TW202319442A - Polyamic acid, polyimide, and use thereof - Google Patents

Abstract

Provided is a polyamic acid that is a copolymerization reaction product of at least carboxylic acids, diamines, and a silsesquioxane compound A having a dicarboxylic anhydride group, wherein the silsesquioxane compound A is obtained by reacting: a thiol group of a condensate B of a thiol-group-containing trialkoxysilane a1 represented by the general formula: R1Si(OR2)3 (in the formula, R1 represents an organic group such as a C1-8 aliphatic hydrocarbon group in which at least 1 hydrogen is substituted by a thiol group, and R2 each independently represent a hydrogen atom, a C1-8 aliphatic hydrocarbon group, etc.) and a thiol-group-free trialkoxysilane a2; and a reactive group composed of a vinyl group, etc., in a dicarboxylic anhydride C having the reactive group.

Description

Polyamic acid, polyimide, and uses thereof

The present invention relates to a polyamic acid containing a novel silsesquioxane compound as a copolymerization component, a polyimide obtained by imidizing this, and its use. Examples of the use include For example: polyimide film, its laminated body, flexible electronic device, etc.

Polyimide films have excellent heat resistance, good mechanical properties, and are widely used in electrical and electronic fields as flexible materials. However, a general polyimide film is colored yellowish brown, so it cannot be applied to parts such as display devices that require light transmission.

On the other hand, display devices are becoming thinner and lighter, and further require flexibility. Therefore, attempts have been made to replace the substrate material from glass substrates with flexible polymer film substrates. However, the colored polyimide film cannot be used as a substrate material of a liquid crystal display that displays by turning on/off light transmission, and can only be applied to peripheral circuits such as TAB and COF mounted on the driving circuit of the display device, and There are very few such as the rear side of reflective display or self-luminous display devices.

Because of this background, we are heading towards the development of colorless and transparent polyimide film. When using polyimide film as a flexible electronic circuit board, in addition to colorless transparency, low coefficient of linear expansion (CTE), and low hysteresis (Rth), resistance to bending and high temperature conditions during circuit formation are required To maintain mechanical strength, it requires high modulus of elasticity, mechanical strength and high glass transition temperature (Tg).

As a representative example, attempts have been made to develop and use colorless and transparent polyimide films such as fluorinated polyimide resins and semi-alicyclic or fully alicyclic polyimide resins (Patent Documents 1 to 3). These films have less coloring and are transparent, but the increase in mechanical strength is not as good as that of colored polyimide films, and thermal decomposition or oxidation reactions will occur in industrial production and intended exposure to high temperatures. Colorlessness and transparency may not always be maintained.

From this point of view, a method of performing heat treatment while spraying gas with a predetermined oxygen content has been proposed (Patent Document 4). However, in an environment with an oxygen concentration of less than 18%, the production cost is high and industrial production is extremely difficult.

Also, as a means to further improve the properties of organic materials, there is a so-called organic-inorganic hybrid technology, which is to impart the properties of inorganic materials, that is, high heat resistance and chemical resistance, by compounding organic materials and inorganic materials. , high surface hardness, etc. For example, it is known that CTE, Rth, and Tg can be improved while maintaining transparency by compounding transparent polyimide and silica nanoparticles. However, as the mixing amount of silica nanoparticles increases, there is a problem that the film becomes hard and brittle, and the mechanical strength decreases.

On the other hand, in silsesquioxane represented by RSiO _3/2 , by giving R a substituent capable of reacting with an organic material, it is possible to easily provide an organic-inorganic hybrid cured product, so it is moving toward practical use research (for example, Patent Document 5). Attempts have been made to improve heat resistance and processability by compounding flexible silsesquioxane and polyimide. It is known that the thermal decomposition temperature increases due to the charge transfer interaction between the imide portion of polyimide and silsesquioxane (Non-Patent Document 1). [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 11-106508 [Patent Document 2] Japanese Patent Laid-Open No. 2002-146021 [Patent Document 3] Japanese Patent Laid-Open No. 2002-348374 [Patent Document 4] WO2008/146637 Publication [Patent Document 5] Japanese Patent No. 3653976 [Non-patent literature]

[Non-Patent Document 1] Thermochimica Acta 2004, 417, pp.133-142 [Non-Patent Document 2] European Polymer Journal 2011, 47 (6), pp. 1328-1337

[Problem to be solved by the invention]

However, the flexible silsesquioxane structure reduces the rigidity of polyimides, so silsesquioxane composite polyimides usually have the problems of relatively low modulus of elasticity and low Tg (non-patent literature 2).

As described above, it is very difficult to manufacture a colorless and transparent polyimide film having a low coefficient of linear expansion, high heat resistance, and high mechanical strength. In the semi-alicyclic or fully alicyclic polyimide, if the monomer component having the alicyclic structure is added, the colorless transparency is improved, but the mechanical strength is lowered, making it difficult to produce as a film. On the other hand, if an aromatic monomer is introduced, although the toughness is improved and the mechanical properties of the film are improved, it becomes easy to be colored and the colorless transparency decreases. By introducing a filler (inorganic component) whose refractive index is similar to that of the resin component, the heat resistance and colorless transparency are improved, and the linear expansion coefficient is reduced, and the processing suitability is improved, but the physical properties of the resin become hard and brittle, and the mechanical properties decrease.

Therefore, practical properties such as heat resistance and mechanical properties are in a trade-off relationship with colorlessness (transparency or whiteness), and a method for producing a polyimide film with improved toughness while maintaining other main properties is particularly desired.

Therefore, an object of the present invention is to provide a polyamic acid which can be used as a raw material and the like for producing a polyimide film whose toughness is improved while maintaining other main characteristics. Another object of the present invention is to provide a polyamic acid composition including such a polyamic acid, and a polyimide obtained by imidizing the polyamic acid.

Furthermore, another object of the present invention is to provide a polyimide film with improved toughness while maintaining other main characteristics, its laminate, and a flexible electronic component using the polyimide film, and its manufacture. method. [Means to solve the problem]

The inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and as a result, found that a polyamic acid containing a novel silsesquioxane compound that introduces a dicarboxylic anhydride group through a reaction with a thiol group as a copolymerization component can achieve the above-mentioned object. , and then completed the present invention.

That is, the present invention includes the following matters.

[1] A polyamic acid, which is a copolymerization reaction product of at least carboxylic acids, diamines, and a silsesquioxane compound A having a dicarboxylic anhydride group, wherein the aforementioned silsesquioxane compound A is composed of The thiol group of the condensate B of a1 and a2 reacts with the reactive group of dicarboxylic acid anhydride C; General formula: Trialkoxysilanes containing thiol groups represented by R ¹ Si(OR ² ) ₃ a1; (wherein, R ¹ represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons, at least one hydrogen of which is substituted with a thiol group Organic group, ^R2 each independently represents a hydrogen atom, an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons or an aromatic hydrocarbon group with 6 to 8 carbons) Alkoxysilanes a2; The reactive group of the dicarboxylic acid anhydride C is at least one reactive group selected from vinyl, alkenyl, cycloalkenyl, alkynyl and acyl chloride.

[2] A polyamic acid, which is a copolymerization reaction product of at least carboxylic acids, diamines, and a silsesquioxane compound A having a dicarboxylic anhydride group, wherein, The aforementioned silsesquioxane compound A has structural units represented by the following general formulas (1) and (2).

(wherein, Q ¹ represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons, Q ² is a single bond, an aliphatic hydrocarbon with 1 to 8 carbons Hydrocarbon group, organic group or carbonyl group in which one or more carbon atoms in a hydrocarbon group with 1 to 8 carbon atoms is replaced by oxygen, X is a carbon-carbon bond or an aliphatic ring with 4 to 10 carbon atoms, and an aromatic group with 6 to 10 carbon atoms A group ring, or a heterocycle in which part of the carbon constituting these is replaced by oxygen or sulfur; more than one of the hydrogens bonded to these rings may also be replaced by a hydrocarbon group; 1.0≤m≤2.0; 1.4≤n≤1.6 ).

(wherein, ^Q represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons; 1.4≤n≤1.6). [3] The polyamic acid according to [1] or [2], wherein the molar ratio of the trialkoxysilanes a2 in the aforementioned silsesquioxane compound A ([the number of moles of a2]/[ The molar number of a1 + the molar number of a2]) or the molar ratio of the structural unit represented by the general formula (2) ([structural unit (2)]/[structural unit (1)+structural unit (2)]) It is not less than 0.1 and not more than 0.7.

[4] The polyamic acid according to [1] or [3], wherein the dicarboxylic anhydride C is selected from compounds represented by the following chemical formulae.

(In the formula, Rx represents an aliphatic hydrocarbon group having 1 to 8 carbons, an alicyclic hydrocarbon group having 4 to 8 carbons, or an aromatic hydrocarbon group having 6 to 8 carbons). [5] The polyamic acid according to any one of [1] to [4], wherein the molar content is based on the divalent monomer derived from the structural unit of the silsesquioxane compound A: ( nA/(nA+nD))×100 (here, nA is obtained by dividing the total number of moles of structural units derived from the aforementioned silsesquioxane compound A by the total number of the aforementioned dicarboxylic acid anhydride groups and multiplying by 2 times The numerical value; nD is the number of moles derived from the structural units of the aforementioned carboxylic acids) is 0.01-10.0 mole%.

[7] 如[1]至[6]中任一項之聚醯胺酸，其中前述二胺類包含4,4’-二胺基-2,2’-雙(三氟甲基)聯苯(TFMB)或4,4’-二胺基苯甲醯胺苯(DABA)。 [6] The polyamic acid according to any one of [1] to [5], wherein the aforementioned carboxylic acid is selected from one or more compounds represented by the following chemical formulae.

[7] The polyamic acid according to any one of [1] to [6], wherein the aforementioned diamines contain 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB) or 4,4'-diaminobenzamidobenzene (DABA).

[8] A polyamic acid composition comprising the polyamic acid according to any one of [1] to [7] and a solvent.

[9] A polyimide obtained by imidizing the polyamic acid according to any one of [1] to [7].

[10] A polyimide film comprising the polyimide according to [9].

[11] The polyimide film according to [10], wherein the coefficient of linear expansion is not more than 40 ppm/K and not less than -20 ppm/K.

[12] The polyimide film according to [10] or [11], wherein the tensile product (tensile product) in the tensile test is 1,000 MPa･% or more and 10,000 MPa･% or less.

[13] A laminate comprising the polyimide film according to any one of [10] to [12] and an inorganic substrate.

[14] A method of manufacturing a flexible electronic component, comprising: A step of forming an electronic component on the polyimide film surface of the laminate as in [13]; and A step of peeling off the aforementioned inorganic substrate.

[15] A flexible electronic component comprising the polyimide film according to any one of [10] to [12] and an electronic component formed on the polyimide film. [Effect of Invention]

According to the present invention, there can be provided a polyamic acid which can be used as a raw material or the like for producing a polyimide film whose toughness is improved while maintaining other main characteristics. In addition, there are provided a polyamic acid composition including the above-mentioned polyamic acid, and a polyimide obtained by imidizing the polyamic acid.

Furthermore, according to the present invention, it is possible to provide a polyimide film having improved toughness while maintaining other main characteristics, a laminate thereof, a flexible electronic device using the polyimide film, and a method of manufacturing the same.

[Mode for Carrying Out the Invention]

The present invention will be described in detail below, but these are only one aspect of the present invention, and the present invention is not limited to these contents.

The polyamic acid of the present invention is a copolymerization reaction product of at least carboxylic acids, diamines and silsesquioxane compound A having dicarboxylic acid anhydride groups. These are described below.

<Sisesquioxane compound A having a dicarboxylic anhydride group> Novel silsesquioxane compound A is a silsesquioxane compound having a dicarboxylic acid anhydride group (hereinafter sometimes simply referred to as "anhydride group"), which is composed of a thiol-containing silsesquioxane The thiol group of the condensate B of the compound reacts with the aforementioned reactive group of dicarboxylic acid anhydride C having at least one reactive group selected from vinyl, alkenyl, cycloalkenyl, alkynyl and acyl chloride groups silsesquioxane compounds.

The condensate B is the condensate B of the following a1 and a2: General formula: Trialkoxysilanes a1 containing thiol groups represented by R ¹ Si(OR ² ) ₃ ; (wherein, R ¹ represents carbon number 1 An organic group in which at least one hydrogen of an aliphatic hydrocarbon group with ∼8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons is substituted with a thiol group, R ² independently represent a hydrogen atom, an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons); trialkoxysilanes a2 without thiol groups.

Here, there are 3 reactive alkoxy groups in the thiol-containing trialkoxysilanes a1 and trialkoxysilanes a2, so the structure of the obtained product becomes a three-dimensional complex structure, so It is not practical for a chemical formula to specify its overall structure. Therefore, the invention of specific objects is defined in the form of product by process.

However, the structure can be partially specified as two repeating units. That is, the novel silsesquioxane compound A preferably has structural units represented by the following general formulas (1) and (2).

(wherein, Q ¹ represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons, Q ² is a single bond, an aliphatic hydrocarbon with 1 to 8 carbons Hydrocarbon group, organic group or carbonyl group in which one or more carbon atoms in the hydrocarbon group with 1 to 8 carbon atoms is replaced by oxygen, X is a carbon-carbon bond or an aliphatic ring with 4 to 10 carbon atoms, and an organic group with 6 to 10 carbon atoms Aromatic rings or heterocyclic rings in which part of the carbon constituting them is substituted by oxygen or sulfur; one or more hydrogens bonded to these rings may also be substituted by hydrocarbon groups; 1.0≤m≤2.0; 1.4≤n≤1.6) .

(wherein, ^Q represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons; 1.4≤n≤1.6). In another aspect, the novel silsesquioxane compound A is not limited to the specificity of the substance carried out by the above-mentioned preparation method, and can also be specified as having the structural units represented by the following general formulas (1) and (2) as 2 repeating unit.

The novel silsesquioxane compound A, for example, can preferably be produced by a production method sequentially comprising the following steps.

In the first step, use an acidic catalyst to hydrolyze the following a1, a2 with water to obtain a reaction mixture x: General formula: thiol group-containing trialkoxysilanes represented by R ¹ Si(OR ² ) ₃ a1 (wherein, ^R represents an organic group in which at least one hydrogen of an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons is replaced by a thiol group ; ^R independently represent a hydrogen atom, an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons or an aromatic hydrocarbon group with 6 to 8 carbons); Oxygen silanes a2; Step 2, removing the aforementioned acidic catalyst from the aforementioned reaction mixture x to obtain a reaction mixture y; Step 3, mixing a polar solvent containing an alkaline catalyst with the aforementioned reaction mixture y and condensing it, In this way, a condensate B with a thiol group is obtained; and the fourth step is to make the aforementioned condensate B and a reactive group having at least one reactive group selected from vinyl, alkenyl, cycloalkenyl, alkynyl, and acyl chloride. The dicarboxylic anhydride C reaction.

In addition, it can also be obtained by combining a commercially available thiol group-containing silsesquioxane compound (condensate B) with at least A reactive group of dicarboxylic acid anhydride C is obtained by the reaction.

＜Condensate B (thiol group-containing silsesquioxane compound)＞ Condensate B is a condensate of trialkoxysilanes a1 containing thiol groups and trialkoxysilanes a2 without thiol groups. As the condensate B, for example, organic/inorganic hybrid resin Compoceran SQ (trade name: SQ107 or SQ109, Arakawa Chemical Co., Ltd.) can be used. Alternatively, the condensate B synthesized by the method including the above-mentioned first step to third step can be used.

<The first step> The first step is to use an acidic catalyst to make the general formula: R ¹ Si(OR ² ) ₃ containing trialkoxysilanes a1 containing thiol groups, trialkoxysilanes without thiol groups A step in which silanes a2 are hydrolyzed with water to obtain a reaction mixture x.

(wherein, ^R represents an organic group in which at least one hydrogen of an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons is replaced by a thiol group ; R ² independently represent a hydrogen atom, an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons or an aromatic hydrocarbon group with 6 to 8 carbons). Here, the limitation of the carbon number such as "carbon number 1 to 8" means the carbon number of the whole organic group containing a substituent. More specifically, in the above general formula, R ¹ represents a hydrocarbon group with 1 to 8 carbons having a straight chain, branched chain or aliphatic ring, or an aromatic hydrocarbon group with 6 to 8 carbons that may also have a hydrocarbon group An organic group in which at least one hydrogen is replaced by a thiol group. R ¹ is preferably a linear hydrocarbon group from the viewpoint of imparting flexibility to the polymer chain, and is preferably an alicyclic hydrocarbon group or an aromatic hydrocarbon group from the viewpoint of improving heat resistance.

R ² each independently represent a hydrogen atom, a hydrocarbon group having 1 to 8 carbons having a straight chain, a branched chain or an alicyclic ring, or an aromatic hydrocarbon group having 6 to 8 carbons which may also have a hydrocarbon group. R ² is preferably an alkyl group having 1 to 4 carbons from the viewpoint of reactivity in hydrolysis reaction. Particularly preferred is methyl or ethyl.

Specific examples of thiol group-containing trialkoxysilanes a1 (hereinafter referred to as component (a1)) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-Mercaptopropyltripropoxysilane, 3-Mercaptopropyltributoxysilane, 1,4-Dimercapto-2-(trimethoxysilyl)butane, 1,4-Dimercapto-2- (Triethoxysilyl)butane, 1,4-Dimercapto-2-(tripropoxysilyl)butane, 1,4-Dimercapto-2-(tributoxysilyl)butane , 2-mercaptomethyl-3-mercaptopropyltrimethoxysilane, 2-mercaptomethyl-3-mercaptopropyltriethoxysilane, 2-mercaptomethyl-3-mercaptopropyltripropoxysilane , 2-mercaptomethyl-3-mercaptopropyltributoxysilane, 1,2-dimercaptoethyltrimethoxysilane, 1,2-dimercaptoethyltriethoxysilane, 1,2-di Mercaptoethyltripropoxysilane, 1,2-dimercaptoethyltributoxysilane, etc., these exemplified compounds may be used alone or in appropriate combination. Among these exemplified compounds, 3-mercaptopropyltrimethoxysilane is particularly preferable because of its high reactivity in the hydrolysis reaction and its easy availability.

Examples of trialkoxysilanes a2 (hereinafter referred to as component (a2)) not having a thiol group include compounds represented by the general formula: R ³ Si(OR ² ) ₃ . (wherein, R ³ represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons; R ² independently represents a hydrogen atom, a carbon number 1 ～8 aliphatic hydrocarbon group, carbon number 4～8 alicyclic hydrocarbon group or carbon number 6～8 aromatic hydrocarbon group). More specifically, R ³ represents a hydrocarbon group having 1 to 8 carbons having a straight chain, a branched chain, or an aliphatic ring, or an aromatic hydrocarbon group having 6 to 8 carbons that may be polymerized with a hydrocarbon group. R ² is the same as that described for the component (a1), but may be the same as or different from R ² in the component (a1).

As specific examples of component (a2), methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyl Triethoxysilane, etc. Component (a2) may be used individually or in combination of 2 or more types. By using these, the amount of thiol groups can be adjusted, so the degree of crosslinking of the polyimide finally obtained can be adjusted, or the ratio of the inorganic component in the polyimide can be increased.

The molar ratio of the trialkoxysilanes a2 in the alkoxysilanes ([the number of moles of a2]/[the number of moles of a1+the number of moles of a2]) is preferably not less than 0.1 and not more than 0.7, more preferably Preferably, it is not less than 0.2 and not more than 0.7. The larger the molar ratio, the less the amount of thiol groups contained in each molecule, and the smaller the value, the greater the amount of thiol groups. By setting it in this range, the obtained polyimide chain will be moderately crosslinked, and the effect of improving physical properties will be sufficient.

The condensate B of thiol group-containing silsesquioxane can be obtained by using component (a1) and component (a2), hydrolyzing them, and then condensing them. In the first step, the alkoxy groups contained in the component (a1) and the component (a2) are converted into silanol groups by the hydrolysis reaction, and alcohol is by-produced.

The amount of water required for the hydrolysis reaction, as a molar ratio ([the number of moles of water used for the hydrolysis reaction]/[the total number of moles of each alkoxy group contained in component (a1) and component (a2)] ), preferably 0.4 to 10. When the molar ratio is more than 0.4 and less than 0.5, some alkoxy groups will remain in the obtained thiol group-containing silsesquioxane, but the adhesion to inorganic materials can be improved. Also, in the case of 0.5 to 10, substantially no alkoxy group remains in the obtained thiol group-containing silsesquioxane, and it is easy to produce a thick-film cured product.

In addition, in addition to component (a1) and component (a2), dialkoxysilanes and/or tetraalkoxysilanes can be further used within the range that does not impair the effect of the present invention (for example, 50 mole % or less). kind.

As the catalyst used for the hydrolysis reaction, any conventionally known acid catalyst capable of functioning as a hydrolysis catalyst can be used arbitrarily. However, since the acid catalyst must be substantially removed after the hydrolysis reaction, it is preferably one that is easy to remove. Examples of such catalysts include formic acid that can be removed under reduced pressure due to its low boiling point, and solid acid catalysts that can be easily removed by methods such as filtration.

Examples of the solid acid catalyst include cation exchange resins, activated clay, carbon-based solid acids, and the like. Among them, cation exchange resins are preferable because they have high catalytic activity and are easy to obtain. As the cation exchange resin, strong acid type cation exchange resin and weak acid type cation exchange resin can be used. Examples of strong acid ion exchange resins include: Diaion SK series, UBK series of the same series, PK series of the same series, HPK25/PCP series of the same series (all are trade names manufactured by Mitsubishi Chemical Co., Ltd.), Amberlite IR120B, and IR124 of the same series, 200CT of the same series, 252 of the same series, Anberjet 1020, 1024 of the same series, 1060 of the same series, 1220 of the same series, Amberlyst 15DRY, 15JWET of the same series, 16WET of the same series, 31WET of the same series, 35WET of the same series (both are product names manufactured by Organo Co., Ltd.); as weak acid type ion exchange resins, Diaion WK series, WK40 of the same series (both are manufactured by Mitsubishi Chemical Co., Ltd.) product name), Amberlite FPC3500, IRC76 of the same series (all are product names manufactured by Olucano Co., Ltd.), etc. The type of ion-exchange resin used can be arbitrarily selected according to the reaction speed and suppression of side reactions, etc., but from the viewpoint of reactivity, a strongly acidic ion-exchange resin is particularly preferred.

The addition amount of an acid catalyst is preferably 0.1-25 mass parts with respect to a total of 100 mass parts of component (a1) and component (a2), More preferably, it is 1-10 mass parts. If it is 25 parts by mass or less, it will be easy to remove in the subsequent step, and it will tend to be economically advantageous. On the other hand, when it is 0.1 mass part or more, it exists in the tendency which reaction time may not become too long, but can make reaction progress appropriately.

The reaction temperature and time can be set arbitrarily according to the reactivity of component (a1) and component (a2), usually about 0-100°C, preferably 20-60°C, about 1 minute to 2 hours. This hydrolysis reaction can be carried out in the presence or absence of a solvent, but preferably no solvent is used. When a solvent is used, the type of the solvent is not particularly limited, and one or more optional solvents can be selected and used, but it is preferable to use the same solvent as that used in the condensation reaction described later.

＜Step 2＞ The second step is a step of obtaining the reaction mixture y by removing the acid catalyst from the reaction mixture x. That is, after the hydrolysis reaction in the first step is completed, the acid catalyst must be substantially removed from the system. If it is not removed, the reaction does not proceed in the condensation reaction described later, the silanol group is not completely consumed, and the system gels due to the abnormally high molecular weight, so the desired thiol group-containing silsesquioxane cannot be obtained (condensation object B).

The method for removing the acid catalyst can be appropriately selected from various known methods according to the catalyst used. For example, as described above, in the case of using formic acid, in the case of removing the solid acid catalyst by reducing pressure, it can be easily removed by filtration or the like after the condensation reaction is completed.

In addition, after the hydrolysis reaction is completed, after the acid catalyst is removed from the system, by-product alcohol and excess water can be removed by decompression and other methods while removing the acid catalyst. Moreover, it can also dilute with the solvent used for condensation reaction after removal, and it is easy to add a hydrolysis reactant in subsequent condensation reaction.

＜Step 3＞ The third step is a step of obtaining a condensate B having a thiol group by mixing and condensing a polar solvent containing an alkaline catalyst with the aforementioned reaction mixture y. During the condensation reaction, water is by-generated between the aforementioned silanol groups, and alcohol is by-generated between the silanol groups and alkoxy groups to form siloxane bonds. In the condensation reaction, any conventionally known alkaline catalyst capable of functioning as a dehydration condensation catalyst can be used arbitrarily.

The alkaline catalyst is preferably one with high alkalinity, and specific examples include alkali salts such as sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium hydroxide (Ca(OH) ₂ ). , 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene and other organic amines, tetramethylammonium hydroxide, Ammonium hydroxides such as tetrabutylammonium hydroxide, etc. These exemplified compounds can be used alone or in appropriate combination. Among these exemplified compounds, tetramethylammonium hydroxide is particularly preferable because it has high catalytic activity and is easy to obtain. Also, when these alkaline catalysts are used as an aqueous solution, the hydrolysis reaction will also proceed in the condensation reaction step, so it is necessary to reduce the amount of water contained in the alkaline catalyst in advance to properly adjust the amount of water used for hydrolysis. .

The addition amount of an alkaline catalyst is preferably 0.01-5 mass parts with respect to a total of 100 mass parts of component (a1) and component (a2), More preferably, it is 0.1-2 mass parts. If the amount of the alkaline catalyst added is less than 5 parts by mass, there is a tendency that the hardened product made by using the obtained thiol group-containing silsesquioxane (condensate B) is not easy to be colored, and it is difficult to remove the catalyst when it is removed. , the removal steps become easier. On the other hand, when it is 0.01 mass part or more, reaction can be made to progress suitably, and there exists a tendency for reaction time not to be too long.

The reaction temperature can be set arbitrarily according to the reactivity of component (a1) and component (a2), and it is usually about 40-150°C, preferably about 60-100°C. The condensation reaction is preferably carried out in the presence of a polar solvent, and from the viewpoint of the stability of the amide acid solution of the obtained silsesquioxane compound A and its copolymer and the quality of the resulting film, it is more preferably not Contains non-polar solvents such as toluene.

The polar solvent is preferably a polar solvent compatible with water, particularly preferably glycol ethers. Moreover, among glycol ethers, dialkyl glycol ether solvents are particularly preferable. Examples of dialkyl glycol ether solvents compatible with water include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and diethylene glycol methyl ether. , Diethylene glycol diethyl ether, etc. Moreover, glycol ether acetate solvents, such as propylene glycol monomethyl ether acetate (PGMEA), dipropylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate, can also be used.

Moreover, the condensation reaction can be performed by sequentially adding a solution containing a hydrolyzate obtained by a hydrolysis reaction to a polar solvent to which a dehydration condensation catalyst has been added at a reaction temperature. The method of adding can be appropriately selected from various known methods. The time required for the addition can be set arbitrarily according to the reactivity of the component (a1) and the component (a2), but it is usually about 30 minutes to 12 hours.

When the condensation reaction is carried out by the above method, it is preferable to carry out the reaction until the unreacted silanol group substantially disappears. When unreacted silanol groups remain, the obtained thiol group-containing silsesquioxane (condensate B) and the composition containing the condensate B decrease in storage stability or decrease in heat resistance, which is not preferable.

In addition, it is preferable to proceed to the total molar ratio of unreacted alkoxy groups ([total moles of unreacted alkoxy groups]/[each alkoxy group contained in component (a1) and component (a2) The total number of moles]) is 0.2 or less, more preferably substantially 0. When the molar ratio exceeds 0 and is less than 0.2, some alkoxy groups remain in the resulting thiol group-containing silsesquioxane (condensate B), from the viewpoint of improving the adhesion to inorganic materials. Look better. From the viewpoint that no alkoxy group remains substantially, it is easy to produce a thick-film cured product, and the cage structure contained in the obtained thiol group-containing silsesquioxane (condensate B) becomes the largest, and the heat resistance of the cured product is From the point of view of sexual improvement, the molar ratio is 0 for the special series. When it is not 0, the amount of random silsesquioxane contained in the obtained condensate B tends to increase, and the molecular weight (Mw) of the condensate B tends to increase.

This condensation reaction is preferably performed after diluting with a solvent until the total concentration of the component (a1) and the component (a2) becomes about 2 to 80% by mass, more preferably 15 to 75% by mass. It is preferable to use a solvent having a boiling point higher than that of water and alcohol produced by the condensation reaction, since these can be distilled off from the reaction system. When the concentration is 2% by mass or more, the thiol group-containing silsesquioxane (condensate B) contained in the obtained curable composition becomes sufficient amount, which is preferable. In the case of 80% by mass or less, gelation is unlikely to occur during the reaction, and the molecular weight of the resulting condensate B tends to be moderate.

After the condensation reaction is over, if the used catalyst is removed, the stability of the thiol-containing silsesquioxane (condensate B) and the polyimide formed from the condensate B will be improved, so it is more stable than good. The removal method can be appropriately selected from various known methods according to the catalyst used. For example, when tetramethylammonium hydroxide is used, after the condensation reaction is completed, it can be removed by methods such as adsorption and removal with a cation exchange resin. ＜Step 4＞ The fourth step is a step of reacting the aforementioned condensate B with dicarboxylic anhydride C having at least one reactive group selected from vinyl, alkenyl, cycloalkenyl, alkynyl, and acyl chloride groups.

As the dicarboxylic anhydride C (hereinafter referred to as component (C)), a dicarboxylic anhydride having a functional group capable of reacting with a thiol group is used. For example, a dicarboxylic acid anhydride having a vinyl group, an acrylic group, a methacrylic group, an allyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group or an acyl chloride group can be used. More preferably, dicarboxylic acid anhydrides having vinyl, alkenyl, cycloalkenyl, alkynyl or acyl chloride groups can be used. As the dicarboxylic anhydride C, the following structure is particularly desirable.

此等之中，下述化合物與具有醯氯基的化合物，因為反應性高而特佳。另外，使用反應性低之二羧酸酐C的情況，僅以UV光難以使反應完全進行，因此較佳係併用氧及氯化鐵等氧化觸媒。

Among them, the following compounds and compounds having an acid chloride group are particularly preferable because of their high reactivity. In addition, when dicarboxylic anhydride C having low reactivity is used, it is difficult to completely proceed the reaction only with UV light, so it is preferable to use an oxidation catalyst such as oxygen and ferric chloride in combination.

又，二羧酸酐C之中，具有芳香環結構的鄰苯二甲酸酐化合物，從提高所得之聚醯亞胺的耐熱性的觀點及可抑制高溫條件下之黃變的觀點來看較佳，結構中具有脂環式結構的馬來酸酐及環己烷二甲酸酐，從可提高無色透明性的觀點來看較佳。

Also, among the dicarboxylic anhydrides C, a phthalic anhydride compound having an aromatic ring structure is preferable from the viewpoint of improving the heat resistance of the obtained polyimide and suppressing yellowing under high temperature conditions. Maleic anhydride and cyclohexanedicarboxylic anhydride having an alicyclic structure in the structure are preferable from the viewpoint of improving colorless transparency.

For the reaction of silsesquioxane containing thiol group (condensate B) and dicarboxylic anhydride C, thiol-ene reaction or reaction between thiol group and chloroacyl group can be used.

It is known that in the case of a thiol-ene reaction, the reaction mechanism differs depending on the kind of carbon-carbon double bond and the presence or absence of a radical polymerization initiator. That is, when a compound having a vinyl group or an allyl group with low radical polymerizability is used as the component (C), only the ene-thiol reaction proceeds, and the thiol group in the condensate B is combined with the thiol group in the component (C) The carbon-carbon double bond of the carbon-carbon double bond is almost 1:1 (mole ratio) reaction and preferably. On the other hand, when a compound having an acrylic group or a methacrylic group having high radical polymerizability is used as the component (C), when a radical polymerization initiator is used in combination, especially the carbon in the component (C)- The polymerization reaction of the carbon double bond also proceeds at the same time, and the thiol group in the condensate B reacts with the carbon-carbon double bond in the component (C) at a ratio of about 1:1 to 100 (molar ratio), so it may not be possible to obtain sufficient Invention effect. From the above-mentioned viewpoint, in the case of using a component (C) having a vinyl group or an allyl group having low radical polymerizability, it is preferable to use a molar ratio ([mole of the thiol group contained in the condensate B The number of moles]/[the number of moles of carbon-carbon double bonds contained in the component (C)) is blended so that it becomes 0.9 to 2.5, more preferably 1.0. When the molar ratio is 0.9 or more, the carbon-carbon double bond is less likely to remain after ultraviolet curing, and the weather resistance tends to be improved. Also, when it is 2.5 or less, the crosslink density of the cured product is sufficient, and the heat resistance tends to be improved.

As an initiator of the thiol-ene reaction, an ultraviolet light source or an organic material, an inorganic material, or oxygen can be used. As a UV light source, for example, high-pressure mercury lamps, halogen lamps, xenon lamps or UV LEDs can be used.

The usable initiator is not particularly limited, and conventionally known photocation initiators, photoradical initiators, and oxidizing agents can be arbitrarily selected. As photocation initiators, there may be mentioned: perzium salts, iodonium salts, metallocene compounds, benzoin tosylate, etc., which are compounds that generate acids due to irradiation with ultraviolet light, and are commercially available as such Products, such as CYRACURE UVI-6970, UVI-6974 of the same series, UVI-6990 of the same series (all are trade names made by Union Carbide Company of the United States), Irgacure 264 (manufactured by BASF Corporation), CIT-1682 (Nippon Soda Co., Ltd. company), etc. The usage-amount of a photocationic polymerization initiator is normally about 10 mass parts or less with respect to 100 mass parts of this composition, Preferably it is 1-5 mass parts.

Examples of photoradical initiators include: Darocur 1173, Irgacure 651, Irgacure 184, Irgacure 907 (all of which are trade names manufactured by BASF Corporation), diphenyl ketone, etc., which are 5 parts by mass relative to 100 parts by mass of the composition About part or less, Preferably it is 0.1-2 mass parts. Also, the reaction can be accelerated by adding an oxidizing agent such as iron oxide or iron chloride. However, in applications requiring high heat resistance and transparency for substrate films, it is desirable to react using an ultraviolet light source or oxygen without using a photoreaction initiator or a photosensitizer.

In the case of a reaction between a thiol group and an acyl chloride group, it is preferable to add an acyl chloride group having an equivalent or more equivalent to the sum of the thiol group amount and the silanol group amount of the silsesquioxane (condensate B). of dicarboxylic anhydrides. If the amount of dicarboxylic acid anhydride with amide chloride group added is small, the by-generated hydrochloric acid will act as a catalyst, and the silanol groups will condense with each other, so there is a tendency to gel easily. If the amount of dicarboxylic anhydride added is large , it will easily reduce this disadvantage. In addition, in this case, unreacted amide chloride groups may be copolymerized with polyamic acid to produce polyamidoimide.

In addition, in the case of the reaction between the thiol group and the chloroacyl group, hydrochloric acid is generated as a by-product, so a base may be added as a pH adjuster. As the base, organic bases, tertiary amines, and inorganic bases can be used. Examples of organic bases include: N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide Amine, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, imidazole, N-methylcaprolactam, imidazole, N,N-dimethylaniline and N , N-diethylaniline. Examples of tertiary amines include pyridine, colin's base, lutidine and triethylamine. Examples of inorganic bases include potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate. However, it is desirable to react using a volatile base for base film applications requiring high heat resistance and transparency. By adding alkali or heating the solution to remove hydrochloric acid, gelation caused by excessive reaction of silsesquioxane can be suppressed.

As a solvent used for reaction, the following are mentioned. Benzene, toluene, xylene, mesitylene, pentane, hexane, heptane, octane, nonane, decane, N,N-dimethylacetamide, N,N-diethylacetamide , N,N-dimethylformamide, N,N-diethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidone, imidazole, N-methyl caprolactam, dimethyl sulfide, diethyl sulfide, dimethyl sulfide, diethyl sulfide, hexamethyl sulfonamide, cresol, phenol, xylenol, diethylene glycol Alcohol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), tetraglyme, propylene glycol monomethyl ether acetate (PGMEA), dioxane , tetrahydrofuran and γ-butyrolactone. At least two of these can also be used in combination. In particular, in consideration of productivity and optical characteristics of the film, it is preferable to use N,N-dimethylacetamide, N-methyl-2-pyrrolidone, or γ-butyrolactone as the main component of the organic solvent. In addition, a poor solvent such as toluene or xylene may be used together with these organic solvents to the extent that the polyimide-based resin or its precursor does not precipitate.

The silsesquioxane compound A having an acid anhydride group obtained in the fourth step can be used directly as a solution after the reaction, but can also be used as a powder by filtering foreign matter or jelly or distilling off the solvent.

<Structure of silsesquioxane compound A having an acid anhydride group> The silsesquioxane compound A that can be obtained in the above manner preferably has the structural units represented by the following general formulas (1) and (2), more preferably only has the structures represented by the general formulas (1) and (2) unit.

(wherein, Q ¹ represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons; Q ² is a single bond, a carbon number 1 to 8 Hydrocarbon group, organic group or carbonyl group in which one or more carbon atoms in the hydrocarbon group with 1 to 8 carbon atoms are replaced by oxygen, X is a carbon-carbon bond, or an aliphatic ring with 4 to 10 carbon atoms, and with 6 to 10 carbon atoms Aromatic rings or heterocyclic rings in which part of the carbon constituting them is substituted by oxygen or sulfur; more than one hydrogen bonded to these can also be substituted by hydrocarbon groups; 1.0≤m≤2.0; 1.4≤n≤1.6 ).

(wherein, ^Q represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons; 1.4≤n≤1.6). More specifically, ^Q in the general formula (1) represents a hydrocarbon group having 1 to 8 carbons having a straight chain, a branched chain, or an aliphatic ring, or an aromatic hydrocarbon group having 6 to 8 carbons that may also have a hydrocarbon group . As Q ¹ , a linear hydrocarbon group is preferable from the viewpoint of imparting flexibility to the polymer chain, and an alicyclic hydrocarbon group or an aromatic hydrocarbon group is preferable from the viewpoint of improving heat resistance.

As a specific example of ^Q1 , a hydrocarbon group or an aromatic hydrocarbon group to which a Si atom and an S atom of the compound of the thiol group-containing trialkoxysilanes a1 are exemplified are bonded.

^Q2 is a single bond, linear or branched hydrocarbon group having 1 to 8 carbon atoms, an oxygen-containing hydrocarbon group or carbonyl group in which one or more carbon atoms are substituted with oxygen. As Q ² , a linear hydrocarbon group is preferable from the viewpoint of imparting flexibility to the polymer chain, and a single bond, alicyclic hydrocarbon group, or aromatic hydrocarbon group is preferable from the viewpoint of improving heat resistance.

X is a carbon-carbon bond, or an aliphatic ring with 4 to 10 carbons, an aromatic ring with 6 to 10 carbons, or a heterocyclic ring in which some of the carbons constituting these are substituted by oxygen or sulfur; One or more hydrogens of the junction may be substituted by hydrocarbon groups. X is preferably a carbon-carbon bond from the viewpoint of imparting flexibility to the polymer chain, and a single bond, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group from the viewpoint of improving heat resistance. In particular, the case where X is an aromatic hydrocarbon group is preferable from the viewpoint of suppressing discoloration under high-temperature conditions while increasing heat resistance.

Specific examples of Q ² and X include, among the reaction residues of the compound exemplified as dicarboxylic anhydride C, the portion from which the dicarboxylic anhydride group has been removed. In addition, an example in which X is a heterocyclic ring in which a part of carbon constituting an aliphatic ring or an aromatic ring is substituted with oxygen or sulfur is represented by the following chemical formula.

Regarding m, it satisfies 1.0≤m≤2.0, and m is preferably 1 from the viewpoint of small steric hindrance and improved reactivity of dicarboxylic anhydride groups. When m is 1.0<m<2.0 (that is, other than an integer), as the component (a1), one having one thiol group and one having two thiol groups are used in combination.

Regarding n, it is 1.4≦n≦1.6, and n is preferably 1.5 from the viewpoint of forming a more uniform three-dimensional structure. Assuming that n is other than 1.5, it means that not only trialkoxysilane but also dialkoxysilane and tetraalkoxysilane are allowed to be mixed in a small amount in the raw material.

Also, ^Q3 in the general formula (2) represents a hydrocarbon group having 1 to 8 carbons having a straight chain, a branched chain, or an aliphatic ring, or an aromatic hydrocarbon group having 6 to 8 carbons which may also have a hydrocarbon group. Q ³ is preferably a short-chain or branched-chain hydrocarbon group or an aromatic hydrocarbon group from the viewpoint of suppressing crystallization and improving heat resistance. Specific examples of ^Q3 include a hydrocarbon group or an aromatic hydrocarbon group bonded to the Si atom of the compound exemplified by trialkoxysilanes a2.

In the silsesquioxane compound A having the structural unit represented by general formula (1) and (2), the molar ratio of the structural unit represented by general formula (2) ([structural unit (2)]/[structural unit ( 1) + structural unit (2)]) is preferably from 0.1 to 0.7, more preferably from 0.2 to 0.7. The larger the molar ratio, the smaller the amount of thioether or thioester groups contained in each molecule, and the smaller the value, the greater the amount of thioether or thioester groups. By setting it in this range, the obtained polyimide chain will be moderately crosslinked, and therefore the improvement effect of a physical property is also sufficient.

The number of acid anhydride groups (functional groups) per molecule of the silsesquioxane compound A is preferably 2-10, more preferably 2.5-6. If the number of functional groups is within this range, the obtained polyimide chains will be moderately cross-linked, so the effect of improving physical properties is sufficient.

The molecular weight of the silsesquioxane compound A is preferably from 400 to 5,000, more preferably from 600 to 3,000. If the molecular weight is within this range, the obtained polyimide is less likely to be uneven, and a uniform cross-linked structure can be easily obtained.

Although general formulas (1) and (2) are easy to obtain random bonds, they can form cage-type (including double-layer type) or partially open cage-type and ladder-type silicon sesquidoles through regular bonding between the two. Oxygen compounds.

As a method for obtaining the silsesquioxane compound A with such a structure, it is possible to obtain a cage type or a partially open cage type in advance at the stage of the condensate B (thiol group-containing silsesquioxane compound), A method using a ladder-type silsesquioxane compound, or a method using a commercially available thiol group-containing silsesquioxane compound having such a structure.

Condensate B can be synthesized by dehydration condensation of dialkylsilanediol or dehydrochlorination reaction of dialkylsilanediol and dialkyldichlorosilane. By adjusting the concentration of the catalyst, solvent or substrate used, the ratio of formation of specific structures can be increased. The resulting product can be purified by recrystallization, solvent cleaning and column separation, and the specific structure can be isolated. The method is not particularly limited, for example, the methods described in the following documents, etc. can be used: general literature ((1) "Wide Application Fields and Technical Trends of Polysiloxane", by Yoshiaki Ono, Chemical Industry Daily Company; (2) "The Science of Silicon", by Nobuo Matsumoto, Society for Electronics, Information and Communication; (3) "The Latest Application Technology of Polysiloxane", supervised by Makoto Kumata and Masa Wada, CMC Publishing; (4) "Selection and Optimum Utilization of Silicon Compounds Technology", edited by Technology Information Association; (5) "Organosilicon Science in the 21st Century", supervised by Tamao Haoping, CMC Publishing; (6) "Chemistry and Application Development of Silsesquioxane Materials", supervised by Ito Maki, CMC publishing). ^TH ₈ , which is one of the cage structures, can be synthesized, for example, by hydrolyzing trichlorosilane in the presence of ferric chloride (Bull. Chem. Soc. Jpn., 73, 215(2000)). Various derivatives can be synthesized by using ^TH ₈ as a starting material and further chemically modifying it. For example, in the case of introducing an organic group by hydrosilylation of ^TH ₈ , the organic group is introduced by reacting an alkenyl compound in the presence of a platinum catalyst. When ^TH ₈ is reacted with chlorine, T ^Cl ₈ is obtained, and if methyl orthoformate is further reacted, a methoxy group can be introduced. T ^Ph ₄ T ^Ph ₃ (ONa) ₃ having a double-layer structure can be produced almost quantitatively by hydrolyzing trimethoxy(phenyl)silane in the presence of sodium hydroxide. As a method for synthesizing the condensate B having a ladder structure, the method of synthesizing by alkali equilibrium reaction using potassium hydroxide as a catalyst after hydrolysis of trichloro(phenyl)silane (Chem.Rev., 95, 1409 (1995)), and a synthesis method by hydrolysis polycondensation of trichloro(phenyl)silane using a related mobile catalyst (Journal of the Silicon Chemical Society, (8), 16(1997)).

In addition, as the silsesquioxane compound A having an acid anhydride group, in the examples described later, those having a random structure are mainly used, thereby making it possible to manufacture a polyimide film with improved toughness while maintaining other main characteristics. . The detailed reason is not clear, but it is considered that the softer (compared to inorganic fillers, etc.) silsesquioxane skeleton becomes a small domain, which easily allows deformation of the polyimide as the base material. Therefore, it is considered that the same effect can be obtained not only when using the silsesquioxane compound A which has a random structure but also when using the silsesquioxane compound A which has another structure mentioned above.

＜Polyamide＞ The polyamic acid of the present invention is at least a copolymerization reaction product of the above-mentioned silsesquioxane compound A having an anhydride group, carboxylic acids and diamines.

Especially when a silsesquioxane compound having more than two acid anhydride groups is used as the silsesquioxane compound A, a crosslinked structure can be formed in the polyimide as a copolymerization component.

Regarding polyimide, in general, practical properties such as heat resistance and mechanical properties are in a trade-off relationship with colorlessness (transparency or whiteness). Therefore, it is particularly desirable to produce a polyimide with improved toughness while maintaining other main properties. imine membrane method.

By using polyamic acid with silsesquioxane compound A as a copolymerization component, it is possible to manufacture a polyimide film with improved toughness while maintaining other main characteristics, so the polyamic acid of the present invention is used as its raw material etc. are particularly useful. The polyimide membrane can be obtained, for example, by a method comprising the steps of synthesizing polyamic acid in a solution, forming a polyamic acid solution into a thin film, and imidizing polyamic acid. step.

＜Synthesis of Polyamic Acid＞ Synthesis of polyamic acid can be carried out, for example, by reacting at least carboxylic acids, diamines, and silsesquioxane compound A having a dicarboxylic anhydride group in a solvent. That is, as monomer components other than the silsesquioxane compound A, at least carboxylic acids and diamines can be used.

The carboxylic acids are not particularly limited, and alicyclic tetracarboxylic anhydrides, aromatic tetracarboxylic anhydrides, tricarboxylic acids and Dicarboxylic acids, etc. From the viewpoint of heat resistance, aromatic ones are preferred, and from the viewpoint of transparency, alicyclic ones are preferred. These may be used alone or in combination of two or more.

As the alicyclic tetracarboxylic acid anhydride in the present invention, 1,2,3,4-cyclobutane tetracarboxylic acid, 1,2,3,4-cyclopentane tetracarboxylic acid, 1,2,3,4 -Cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,3',4,4'-bicyclohexyltetracarboxylic acid, bicyclo[2,2,1]heptane-2,3 ,5,6-tetracarboxylic acid, bicyclo[2,2,2]octane-2,3,5,6-tetracarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5, 6-tetracarboxylic acid, tetrahydroanthracene-2,3,6,7-tetracarboxylic acid, tetrahydro-1,4:5,8:9,10-trimethanoanthracene-2,3,6,7 -tetracarboxylic acid, decahydronaphthalene-2,3,6,7-tetracarboxylic acid, decahydro-1,4:5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acid, Hydrogen-1,4-ethylidene-5,8-methanophthalene-2,3,6,7-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2 "-Norbornane-5,5",6,6"-tetracarboxylic acid (alias "norbornane-2-spiro-2'-cyclopentanone-5'-spiro-2"-norbornane-5, 5”,6,6”-tetracarboxylic acid”), methylnorbornane-2-spiro-α-cyclopentanone-α’-spiro-2”-(methylnorbornane)-5,5”, 6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclohexanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid (alias "norbornane Bornane-2-spiro-2'-cyclohexanone-6'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid"), Methylnorbornane-2-spiro -α-cyclohexanone-α'-spiro-2"-(methylnorbornane)-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclopropanone-α '-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclobutanone-α'-spiro-2"-norbornane- 5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cycloheptanone-α'-spiro-2"-norbornane-5,5",6,6"-tetra Formic acid, norbornane-2-spiro-α-cyclooctanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic acid, norbornane-2-spiro-α -Cyclononanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclodecanone-α'-spiro-2 "-Norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cycloundecanone-α'-spiro-2"-norbornane-5,5" ,6,6”-tetracarboxylic acid, norbornane-2-spiro-α-cyclododecanone-α’-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic acid, norbornane Bornane-2-spiro-α-cyclotridecanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic acid, norbornane-2-spiro-α-ring Tetradecone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentadecone-α'-spiro-2 "-Norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclopentanone)-α'-spiro-2"-norbornane-5 ,5",6,6"-Tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclohexanone)-α'-spiro-2"-norbornane-5,5",6,6 " - Tetracarboxylic acids such as tetracarboxylic acid and their anhydrides. Among these, dianhydrides having two acid anhydride structures are preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dicarboxylic acid dihydrogen are particularly preferred. anhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, more preferably 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride The dianhydride is more preferably 1,2,3,4-cyclobutanetetracarboxylic dianhydride. In addition, these may be used individually, and may use 2 or more types together.

Examples of the aromatic tetracarboxylic acid anhydride in the present invention include: 4,4'-(2,2-hexafluoroisopropylidene)diphthalic acid, 4,4'-oxydiphthalic acid, Bis(1,3-dioxo-1,3-dihydro-2-benzofuran-5-carboxylic acid)1,4-phenylene, bis(1,3-dioxo-1, 3-dihydro-2-benzofuran-5-yl)benzene-1,4-dicarboxylate, 4,4'-[4,4'-(3-oxo-1,3-dihydro- 2-benzofuran-1,1-diyl)bis(benzene-1,4-diyloxy)]diphenyl-1,2-dicarboxylic acid, 3,3',4,4'-diphenyl Ketotetracarboxylic acid, 4,4'-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(toluene-2,5-diyloxy)] Diphenyl-1,2-dicarboxylic acid, 4,4'-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(1,4-xylene -2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran -1,1-diyl)bis(4-isopropyl-toluene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-( 3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(naphthalene-1,4-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4 ,4'-[4,4'-(3H-2,1-benzoxythiol-1,1-dioxide-3,3-diyl)bis(benzene-1,4-diyloxy )]diphenyl-1,2-dicarboxylic acid, 4,4'-diphenone tetracarboxylic acid, 4,4'-[(3H-2,1-benzoxythiol-1,1-dioxide -3,3-diyl)bis(toluene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[(3H-2,1-benzoxythiol -1,1-dioxide-3,3-diyl)bis(1,4-xylene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'- [4,4'-(3H-2,1-Benzothiol-1,1-dioxide-3,3-diyl)bis(4-isopropyl-toluene-2,5-diyl Oxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-(3H-2,1-benzoxythiol-1,1-dioxide-3,3- Diyl)bis(naphthalene-1,4-diyloxy)]diphenyl-1,2-dicarboxylic acid, 3,3',4,4'-diphenyl ketone tetracarboxylic acid, 3,3',4 ,4'-diphenyl ketone tetracarboxylic acid, 3,3',4,4'-diphenyl tetracarboxylic acid, 3,3',4,4'-biphenyl tetracarboxylic acid, 2,3,3',4 '-Biphenyltetracarboxylic acid, pyromellitic acid, 4,4'-[spiro(dibenzopyran-9,9'-fluorene)-2,6-diylbis(oxycarbonyl)]diphthalic acid Tetracarboxylic acids such as dicarboxylic acid, 4,4'-[spiro(dibenzopyran-9,9'-fluorene)-3,6-diylbis(oxycarbonyl)]diphthalic acid and the like and other anhydrides. In addition, aromatic tetracarboxylic acids may be used alone or in combination of two or more.

Tricarboxylic acids include trimellitic acid, 1,2,5-naphthalenetricarboxylic acid, diphenyl ether-3,3',4'-tricarboxylic acid, diphenylene-3,3',4'- Aromatic tricarboxylic acids such as tricarboxylic acid or hydrogenated products of the above-mentioned aromatic tricarboxylic acids such as hexahydrotrimellitic acid, ethylene glycol bis-trimellitate, propylene glycol bis-trimellitate, 1,4-butanediol Alkanediol bis-trimellitic acid esters such as alcohol bis-trimellitate and polyethylene glycol bis-trimellitate, and their monoanhydrides and esterified products. Among them, monoanhydrides having one acid anhydride structure are preferable, and trimellitic anhydride and hexahydrotrimellitic anhydride are particularly preferable. In addition, these may be used alone or in combination of multiple types.

Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, and 4,4'-oxydibenzoic acid, or 1,6-cyclohexyl Alkane dicarboxylic acid and other above-mentioned aromatic dicarboxylic acid hydrides, oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane dicarboxylic acid acid, dodecanedioic acid, 2-methylsuccinic acid and their acyl chlorides or esters, etc. Among them, aromatic dicarboxylic acids and their hydrogenated products are preferable, and terephthalic acid, 1,6-cyclohexanedicarboxylic acid, and 4,4'-oxydibenzoic acid are particularly preferable. Moreover, dicarboxylic acids may be used individually or in combination of multiple types.

As the carboxylic acids, one or more compounds selected from the compounds represented by the following chemical formulas are particularly preferred.

The diamines in the present invention are not particularly limited, and aromatic diamines, aliphatic diamines, aliphatic diamines, Alicyclic diamines. From the viewpoint of heat resistance, aromatic diamines are preferred, and from the viewpoint of transparency, alicyclic diamines are preferred. Diamines may be used alone or in combination of two or more.

Examples of aromatic diamines include 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl)-2- Propyl]benzene, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminobis Benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy) ) phenyl] ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]pyridine, 2,2-bis[4 -(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoro Propane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4-amino-N-(4-aminophenyl) benzamide, 3 ,3'-Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-trifluoromethyl-4,4'- Diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3' -Diaminodiphenylene, 3,4'-diaminodiphenylene, 4,4'-diaminodiphenylene, 3,3'-diaminodiphenylene, 3,4'-diaminodiphenylphenone, 4,4'-diaminodiphenylphenone, 3,3'-diaminodiphenylketone, 3,4'-diaminodiphenylketone, 4,4'-diaminodiphenylketone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane Methane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4 -(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1,2-bis[4-(4-amine phenoxy)phenyl]propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)benzene base] propane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,3-bis[4-(4-aminophenoxy)phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3- Bis[4-(4-aminophenoxy)phenyl]butane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy) )-3-methylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3-methylphenyl]propane, 2-[4-(4-aminophenoxy base)phenyl]-2-[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy) -3,5-Dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4, 4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl] Thioether, bis[4-(4-aminophenoxy)phenyl]pyridine, bis[4-(4-aminophenoxy)phenyl]pyridine, bis[4-(3-aminophenoxy)phenylene oxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 4, 4'-bis[(3-aminophenoxy)benzoyl]benzene, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4 -(3-aminophenoxy)phenyl]propane, 3,4'-diaminodiphenylsulfide, 2,2-bis[3-(3-aminophenoxy)phenyl]-1 ,1,1,3,3,3-Hexafluoropropane, bis[4-(3-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy) Phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, bis[4-(3-aminophenoxy)phenyl]pyridine, 4, 4'-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl Ether, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl ketone, 4,4'-bis[4-(4-amino -α,α-Dimethylbenzyl)phenoxy]diphenylphenone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]phenone, 1,4-bis[ 4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)phenoxy-α, α-Dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3 -Bis[4-(4-amino-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-methylbenzene oxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-cyanophenoxy)-α,α-dimethylbenzyl]benzene , 3,3'-diamino-4,4'-diphenoxydiphenyl ketone, 4,4'-diamino-5,5'-diphenoxydiphenyl ketone, 3,4 '-Diamino-4,5'-diphenoxydiphenyl ketone, 3,3'-diamino-4-phenoxydiphenyl ketone, 4,4'-diamino-5- Phenoxydiphenyl ketone, 3,4'-diamino-4-phenoxydiphenyl ketone, 3,4'-diamino-5'-phenoxydiphenyl ketone, 3,3 '-Diamino-4,4'-bisphenoxydiphenyl ketone, 4,4'-diamino-5,5'-bisphenoxydiphenyl ketone, 3,4'- Diamino-4,5'-biphenoxydiphenyl ketone, 3,3'-diamino-4-biphenoxydiphenyl ketone, 4,4'-diamino-5- Biphenoxy diphenyl ketone, 3,4'-diamino-4-biphenoxy diphenyl ketone, 3,4'-diamino-5'-biphenoxy diphenyl ketone, 1,3-bis(3-amino-4-phenoxybenzoyl)benzene, 1,4-bis(3-amino-4-phenoxybenzoyl)benzene, 1,3- Bis(4-amino-5-phenoxybenzoyl)benzene, 1,4-bis(4-amino-5-phenoxybenzoyl)benzene, 1,3-bis(3- Amino-4-biphenoxybenzoyl)benzene, 1,4-bis(3-amino-4-biphenoxybenzoyl)benzene, 1,3-bis(4-amino -5-biphenoxybenzoyl)benzene, 1,4-bis(4-amino-5-biphenoxybenzoyl)benzene, 2,6-bis[4-(4-amine Base-α,α-Dimethylbenzyl)phenoxy]benzonitrile, 4,4'-[9H-Ocea-9,9-diyl]bisaniline (alias "9,9-bis(4- Aminophenyl) fluorine"), spiro(dibenzopyran-9,9'-fluorene)-2,6-diylbis(oxycarbonyl)]bisaniline, 4,4'-[spiro(di Benzopyran-9,9'-fluorene)-2,6-diylbis(oxycarbonyl)]bisaniline, 4,4'-[spiro(dibenzopyran-9,9'-fluorene) -3,6-diylbis(oxycarbonyl)]bisaniline, 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl) Benzoxazole, 5-amino-2-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2'-para Phenylbis(5-aminobenzoxazole), 2,2'-p-phenylenebis(6-aminobenzoxazole), 1-(5-aminobenzoxazole)-4- (6-aminobenzoxazole)benzene, 2,6-(4,4'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2 ,6-(4,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole, 2,6-(3,4'-diaminodiphenyl Phenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,4'-diaminodiphenyl)benzo[1,2-d:4 ,5-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6 -(3,3'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole, etc. In addition, part or all of the hydrogen atoms on the aromatic ring of the above-mentioned aromatic diamine may be substituted by a halogen atom, an alkyl group or an alkoxy group with 1 to 3 carbons, or a cyano group, and the aforementioned alkyl group with 1 to 3 carbons Or part or all of the hydrogen atoms of the alkoxy group may be substituted by halogen atoms.

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethane Cyclohexane, 1,4-diamino-2-n-propylcyclohexane, 1,4-diamino-2-isopropylcyclohexane, 1,4-diamino-2-n- Butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-secondary butylcyclohexane, 1,4-diamino-2 -Tertiary butylcyclohexane, 4,4'-methylenebis(2,6-dimethylcyclohexylamine), 9,10-bis(4-aminophenyl)adenine, 2,4 -Dimethyl bis(4-aminophenyl)cyclobutane-1,3-dicarboxylate and the like.

As diamines, it is especially preferred to include 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB) or 4,4'-diaminobenzamide benzene (DABA), more preferably 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB) or 4,4'-diaminobenzamidobenzene (DABA) .

The molar content based on the divalent monomer derived from the structural unit of silsesquioxane compound A: (nA/(nA+nD))×100 (here, nA is derived from the aforementioned silsesquioxane The value obtained by dividing the total number of moles of the structural units of the oxane compound A by the total number of the aforementioned dicarboxylic acid anhydride groups and multiplying by 2 times, nD is the molar number of the structural units derived from the aforementioned carboxylic acids) is preferably 0.01～ 10.0 mole %. When the above-mentioned molar content of silsesquioxane compound A is 0.01 mol% or more, the compounding effect can be obtained, and if the above-mentioned molar content is 10.0 mol% or less, polyamic acid solution is less likely to generate Gel-forming, easy to obtain stability over time. Therefore, the above molar content is more preferably 0.1 to 5.0 mole%.

Especially when the number of acid anhydride groups per molecule of the silsesquioxane compound A is 2 to 5, the molar content is more preferably 0.1 to 10.0 mole%. Also, when the number of acid anhydride groups per molecule of the silsesquioxane compound A is 5 to 10, the molar content is more preferably 0.1 to 5.0 mole%.

As the solvent used in the synthesis of polyamic acid, any solvent can be used as long as it can dissolve the polyamic acid and its monomer, for example: aprotic solvent, phenolic solvent, ether and Alcohol-based solvents, etc.

Specifically, examples of the aprotic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methyl Amide-based solvents such as caprolactam, 1,3-dimethylimidazolidinone, and tetramethylurea; lactone-based solvents such as γ-butyrolactone and γ-valerolactone; hexamethylphosphoramide Phosphorus-containing amide-based solvents such as hexamethylphosphine triamide; sulfur-containing solvents such as dimethylsulfoxide, dimethylsulfoxide, and cyclobutylene; ketones such as cyclohexanone and methylcyclohexanone solvents; tertiary amine solvents such as picoline and pyridine; ester solvents such as acetic acid (2-methoxy-1-methylethyl), etc.

Examples of phenolic solvents include: phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, Xylenol, 3,4-xylenol, 3,5-xylenol, etc. Examples of ether and glycol-based solvents include: 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane alkane, bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1,4-dioxane, etc.

Among them, from the viewpoint of solubility and coating film formation, the solvent preferably contains N-methyl-2-pyrrolidone, N,N'-dimethylacetamide, or γ-butyrolactone. as the main component. The above-mentioned solvents may be used alone or in combination of two or more.

As conditions at the time of synthesis, the reaction temperature is preferably from -30 to 200°C, more preferably from 20 to 180°C, particularly preferably from 20 to 100°C. Stirring is continued at room temperature (20-25° C.) or at an appropriate reaction temperature, and the time point at which the viscosity of the polyimide precursor becomes constant can be regarded as the end of the reaction. The above reaction can generally be completed within 3 to 100 hours.

＜Polyamide Composition＞ The polyamic acid composition of the present invention comprises the above-mentioned polyamic acid and a solvent. The polyamic acid composition may contain a solvent different from the solvent used for synthesis, but it is preferable to contain the solvent used for synthesis from the viewpoint of avoiding complicated production steps. Therefore, the main component of the solvent contained in the polyamide acid composition is preferably N-methyl-2-pyrrolidone, N,N'-dimethylacetamide or γ-butyrolactone.

The content of polyamic acid is preferably from 5 to 30% by mass, more preferably from 10 to 20% by mass, in the polyamic acid composition from the viewpoint of film thickness at the time of film formation. If the content is within this range, a thin film with excellent handling and film thickness can be obtained.

The polyamic acid composition may further include optional components such as adhesion imparting agents, surfactants, leveling agents, antioxidants, UV absorbers, chemical imidization agents, and colorants. Moreover, the filler etc. which a polyimide film can contain may be contained further.

＜Polyimide＞ The polyimide of the present invention is obtained by imidizing the polyamic acid described above. Polyimide can be obtained, for example, by heating the aforementioned polyamic acid. By heating, the carboxyl groups of the polyamic acid are respectively dehydrated and ring-closed, and the polyamic acid undergoes imidization to form a polyimide structure.

Polyimide can be obtained by heating polyamic acid in a solvent. The heating temperature for imidizing polyamic acid is preferably 150 to 220°C in a solvent.

Also, polyimide can be provided as a film-like or film-like molded article by applying a polyamic acid composition containing a solvent to a substrate and heating as described later. The heating temperature for imidizing polyamic acid is preferably 250 to 400° C. in a state where the solvent is dried to a certain extent.

In addition, polyimide can also be obtained by chemical imidization instead of thermal imidization. In this case, it is preferable to use a tertiary amine as an imidization accelerator. The tertiary amine is further preferably a heterocyclic tertiary amine. Preferable specific examples of heterocyclic tertiary amines include pyridine, 2,5-diethylpyridine, picoline, quinoline, and isoquinoline.

＜Polyimide film＞ The polyimide film of the present invention comprises the polyimide as described above. When the polyimide film is composed of two or more layers, at least one layer only needs to contain the polyimide of the present invention.

The polyimide film can be obtained, for example, by casting a polyamic acid solution on a substrate and heating to volatilize the solvent to form a uniform green film with a thickness of 1 to 100 μm, which is then imidized . Examples of the substrate used when forming a film by such a casting method include a polymer film, a glass plate, a silicon rubber plate, a metal plate, and the like.

As the polymer film, polyethylene terephthalate film A4100 (manufactured by Toyobo Co., Ltd.), for example, can be used. In addition, when obtaining a green film with a predetermined thickness, the method of adjusting the concentration of the polyamic acid solution, the method of adjusting the distance between the coating machines, and the method of repeating casting and lamination to achieve the target film thickness can be used to make the target film. Thick film substrate. Furthermore, a polyimide film can be obtained by heat-treating the obtained green film to perform thermal imidization.

The polyimide film may have a single-layer configuration, or may have a laminated configuration of two or more layers. From the viewpoint of the physical strength of the polyimide film and the ease of peeling from the inorganic substrate, a laminated structure of two or more layers is preferable, and a laminated structure of three or more layers is also acceptable. In addition, in this specification, the physical properties (yellow index, total light transmittance, haze, etc.) when the polyimide film is composed of two or more layers refer to the properties of the entire polyimide film unless otherwise specified. value.

The thickness of the polyimide film is preferably at least 5 μm, more preferably at least 7 μm. The upper limit of the thickness of the polyimide film is not particularly limited, but for use as a flexible electronic component, it is preferably less than 200 μm, more preferably less than 90 μm, and even more preferably less than 50 μm. If it is too thin, it will be difficult to form a film and to transport it, and if it is too thick, it will be difficult to transport it as a roll.

The total light transmittance of the polyimide film in the present invention is preferably above 75%, more preferably above 85%, even more preferably above 87%, even more preferably above 88%. The upper limit of the total light transmittance of the polyimide film is not particularly limited, but it is preferably less than 98%, more preferably less than 97%, in order to be used as a flexible electronic component.

The haze of the polyimide film in the present invention is preferably 1.0 or less, more preferably 0.8 or less, further preferably 0.5 or less, still more preferably 0.3 or less.

The yellowness index (hereinafter also referred to as "yellow index" or "YI") of the polyimide film in the present invention is preferably 20 or less, more preferably 15 or less, more preferably 10 or less, and more preferably 5 or less . The lower limit of the yellowness index of the polyimide film is not particularly limited, but it is preferably at least 0.1, more preferably at least 0.2, and even more preferably at least 0.3 for use as a flexible electronic component.

The thickness direction retardation (Rth) of the polyimide film in the present invention is preferably less than 500 nm, more preferably less than 300 nm, more preferably less than 200 nm, and more preferably less than 100 nm. The lower limit of Rth of the polyimide film is not particularly limited, but it is preferably 0.1 nm or more, more preferably 0.5 nm or more for use as a flexible electronic device.

In addition, a colorless and highly transparent polyimide film exhibiting the coefficient of linear expansion (CTE) of the present invention can be realized even if it is stretched during the film-forming process of the polyimide film. This extension operation can be realized by the following method: apply the polyimide solution on the support body for polyimide film production and dry it to become a polyimide film containing 1 to 50% by mass of solvent, and then In the process of drying the polyimide film containing 1 to 50% by mass of solvent on the support or in the state peeled off from the support for making the polyimide film, It extends 1.5 times to 4.0 times in the MD direction and 1.4 times to 3.0 times in the TD direction. At this time, an unstretched thermoplastic polymer film is used as a support for making a polyimide film, and after the thermoplastic polymer film and the polyimide film are simultaneously stretched, the stretched polyimide film is The thermoplastic polymer film is peeled off, thereby preventing scratches on the polyimide film especially when stretching in the MD direction, and a higher-quality colorless and highly transparent polyimide film can be obtained.

The average coefficient of linear expansion (CTE) of the aforementioned polyimide film from 50° C. to 200° C. is preferably below 40 ppm/K. More preferably, it is 35 ppm/K or less. More preferably, it is -20 ppm/K or more, and even more preferably, it is -10 ppm/K or more. If the CTE is within the aforementioned range, the difference between the branch linear expansion coefficient and the general support (inorganic substrate) can be kept relatively small, even if it is subjected to a heating process, the polyimide film can be prevented from peeling off from the inorganic substrate or together with the support The body warps together. Here, CTE is a factor that exhibits reversible stretching with respect to temperature. In addition, the measurement method of the CTE of the aforementioned polyimide film is based on the method described in the examples.

The aforementioned polyimide film may contain a filler. The filler is not particularly limited, and examples thereof include silicon dioxide, carbon, and ceramics, among which silicon dioxide is preferable. These fillers may be used alone or in combination of two or more. By adding the filler, protrusions can be imparted to the surface of the polyimide film, thereby improving the smoothness of the surface of the polyimide film. Also, by adding fillers, the CTE and Rth of the polyimide film can be lowered. The average particle diameter of the filler is preferably at least 1 nm, more preferably at least 5 nm. Also, it is preferably not more than 1 μm, more preferably not more than 500 nm, and still more preferably not more than 100 nm.

The content of the filler in the polyimide film is preferably adjusted according to the average particle size of the filler. When the particle size of the filler is 30 nm or more, it is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, still more preferably 0.01 to 2% by mass, and most preferably 0.01 to 1% by mass. On the other hand, when the average particle diameter is less than 30 nm, it is preferably 0.01 to 50% by mass, more preferably 0.01 to 40% by mass, further preferably 0.01 to 30% by mass, and particularly preferably 0.01 to 20% by mass. By adjusting the content within the above range, the smoothness of the surface of the polyimide film can be maintained at a high degree without impairing the transparency of the polyimide film, and the CTE and CTE of the polyimide film can be lowered. Rth.

The method of adding the filler to the polyimide film is not particularly limited, and examples thereof include a method of adding the filler as a powder during or after the preparation of the aforementioned polyamic acid (polyimide precursor) solution, The method of adding in the form of a filler/solvent (slurry), etc. Among them, the method of adding in a slurry is particularly preferable. The slurry is not particularly limited, and examples include: a slurry in which silicon dioxide with an average particle diameter of 10 nm is dispersed in N,N-dimethylacetamide (DMAC) at a concentration of 20% by mass (for example, Nissan Chemical Industry Co., Ltd. "Snowtex (registered trademark) DMAC-ST", a slurry in which silicon dioxide with an average particle diameter of 80 nm is dispersed in N,N-dimethylacetamide (DMAC) at a concentration of 20% by mass (for example, Nissan Chemical Industrial "Snowtex (registered trademark) DMAC-ST-ZL"), a slurry in which silicon dioxide with an average particle size of 10 nm is dispersed in N-methylpyrrolidone (NMP) at a concentration of 20% by mass (for example, Nissan "Snowtex (registered trademark) NMP-ST" manufactured by Chemical Industry, etc. The aforementioned polyimide film may contain a colorant. For example, by mixing a blue colorant in a pale yellow polyimide film, the Y.I. of the film can be lowered. Examples of the coloring agent include organic pigments, inorganic pigments, and dyes, and organic pigments and inorganic pigments are preferred in order to improve the heat resistance, reliability, and light resistance of the colored film. Examples of organic pigments include: diketopyrrolopyrrole (diketopyrrolopyrrole) pigments; azo pigments such as azo, disazo, and polyazo; Cyan pigments; anthraquinone pigments such as aminoanthraquinone, diaminodianthraquinone, anthrapyrimidine, flavone, anthanthrone (anthanthrone), indanthrene, pyranthrone, and purple anthrone; quinone Acrone series pigments; two 㗁𠯤 series pigments; perinone series pigments; perylene series pigments; sulfur indigo series pigments; isoindoline series pigments; isoindolinone series pigments; quinophthalone yellow (quinophthalone) Department of pigments; Shihlin (threne) pigments; metal complex pigments, etc. Examples of inorganic pigments include titanium oxide, zinc white, zinc sulfide, lead white, calcium carbonate, precipitated barium sulfate, white carbon, alumina white, kaolinite clay, talc, bentonite, black iron oxide, cadmium red , red lead, molybdenum red, molybdenum orange, chrome vermilion, yellow lead, cadmium yellow, yellow iron oxide, thiazole yellow (titan yellow), chromium oxide, chrome green, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, Ultramarine Blue, Prussian Blue, Cobalt Blue, Sky Blue, Cobalt Silicon Blue, Cobalt Zinc Silicon Blue, Manganese Violet, Cobalt Violet, etc. Examples of dyes include azo dyes, anthraquinone dyes, condensed polycyclic aromatic carbonyl dyes, indigo dyes, carbocation dyes, phthalocyanine dyes, methine dyes, and polymethine dyes.

The tensile rupture strength of the aforementioned polyimide film is preferably at least 60 MPa, more preferably at least 120 MPa, even more preferably at least 160 MPa. The upper limit of the tensile rupture strength is not particularly limited, but it is actually less than about 1000 MPa. When the tensile rupture strength is at least 60 MPa, the polyimide film can be prevented from being broken when peeled from the inorganic substrate. In addition, the measuring method of the tensile rupture strength of the said polyimide film is based on the method described in an Example. In addition, when using a casting applicator (casting applicator) to apply on a glass substrate and then produce it, let the two directions perpendicular to the parallel direction and the vertical direction in the casting applicator application be respectively (MD direction) and (TD direction) . The following tensile elongation at break and tensile modulus of elasticity are also the same.

The tensile elongation at break of the aforementioned polyimide film is preferably at least 1%, more preferably at least 5%, and even more preferably at least 10%. When the aforementioned tensile elongation at break is 5% or more, the handleability is excellent. In addition, the measurement method of the tensile elongation at break of the aforementioned polyimide film is based on the method described in the examples.

The tensile modulus of the aforementioned polyimide film is preferably above 2 GPa, more preferably above 3 GPa, even more preferably above 4 GPa. When the tensile modulus of elasticity is 3 GPa or more, the polyimide film exhibits little tensile deformation when peeled from the inorganic substrate and is excellent in handleability. The aforementioned tensile modulus of elasticity is preferably 20 GPa or less, more preferably 12 GPa or less, even more preferably 10 GPa or less. If the above-mentioned tensile modulus of elasticity is 20 GPa or less, the above-mentioned polyimide film can be used as a flexible film. In addition, the measuring method of the tensile elastic coefficient of the aforementioned polyimide film is based on the method described in the examples.

The above-mentioned polyimide film maintains a certain degree of tensile elastic coefficient while improving toughness, so compared with the conventional polyimide film, the tensile product, which is the product of tensile strength and elongation, is improved. That is, the tensile product of the polyimide film of the present invention in the tensile test is preferably at least 1,000 MPa·%, more preferably at least 1,200 MPa·%. The upper limit is not particularly set, but from the viewpoint of the handleability of the film, the tensile product in the tensile test is preferably 10,000 MPa·% or less.

The aforementioned polyimide film is preferably manufactured as a long polyimide film having a width of 300 mm or more and a length of 10 m or more and can be obtained in the form of a roll, more preferably in the form of a roll wound on a core. Morphology of the polyimide film. If the aforementioned polyimide film is wound into a roll, it is easy to transport in the form of the polyimide film wound into a roll.

In the aforementioned polyimide film, in order to ensure handleability and productivity, it is preferable to add/contain 0.03 to 3% by mass of a slippery material (particle) with a particle diameter of about 10 to 1000 nm in the polyimide film to impart The surface of the polyimide film is finely uneven to ensure smoothness.

In addition, when the polyimide film has a laminated structure of two or more layers, if the difference in CTE of each layer is different, it will cause warping, which is not preferable. Therefore, the CTE difference between the 1st polyimide film layer in contact with the inorganic substrate and the 2nd polyimide film layer not in contact with the aforementioned inorganic substrate but adjacent to the 1st polyimide film is preferably 40ppm/ K or less, more preferably 30 ppm/K or less, even more preferably 15 ppm/K or less. In particular, among the aforementioned second polyimide films, the layer with the thickest film thickness is preferably within the aforementioned range. Moreover, it is preferable that the polyimide film has a symmetrical structure in the film thickness direction, since warping is less likely to occur.

In the above-mentioned polyimide film composed of two or more layers, especially the first polyimide film layer in contact with the above-mentioned inorganic substrate and the second polyimide film layer adjacent to the above-mentioned first polyimide film layer The mixed thickness of the interface of the film layer (hereinafter also referred to as "the second polyimide film layer) only needs to be less than the single-layer thickness of the first polyimide film layer and the single-layer thickness of the second polyimide film layer. The sum of the thicknesses is sufficient, and is not particularly limited, preferably less than 99% of the sum of the single-layer thickness of the first polyimide film layer and the single-layer thickness of the second polyimide film layer, more preferably 80% or less. % or less, preferably less than 50%. Also, the lower limit is not particularly limited. In industry, there is no problem as long as it is more than 10nm, and there is no problem if it is more than 20nm. Also, the functions of each layer are obviously different, and it must be sufficient without canceling each other. In the case of performing each function, it is preferable to suppress the proportion of the mixed region in each layer to 50% or less, more preferably to 30% or less, and most preferably to 10% or less.

The means for forming a layer with little mixing is not particularly limited. Compared with making the first polyimide film layer and the second polyimide film layer by solution film formation at the same time, it is better to make the first polyimide film layer first. Any one layer of the imide film layer or the second polyimide film layer is made into the next layer after a heating step. The heating step includes both the intermediate stage and the end state. After the heating step is completed, the next layer can be formed with less mixing, but the surface of the finished film has mostly lost its reactivity, and there are few functional groups on the surface, which may lead to weak adhesion between the two layers and cause practical problems. Therefore, even in the case of little mixing, it is desirable to have an interface where mixing of 10 nm or more occurs.

By forming a film composed of two layers of materials (resins) having different physical properties, it is also possible to produce a film having various properties at the same time. Furthermore, by laminating into a symmetrical structure in the thickness direction (for example, the first polyimide film layer/the second polyimide film layer/the first polyimide film layer), the CTE of the film as a whole The balance becomes good, and a film which does not easily warp can be formed. In addition, it is considered that by using either layer as a layer capable of absorbing ultraviolet light or infrared light, it can be characterized in terms of spectral characteristics, and it is considered that the entrance and exit of light can be controlled by layers with different refractive indices. In addition, by adding a slip agent to the first polyimide film layer, the optical and thermal properties of the entire film can be kept similar to those of the second polyimide film layer, and the smoothness of the film can be improved. In this case, the polymer compositions of the first polyimide film layer and the second polyimide film layer may be the same or different.

As a means of producing a film composed of two or more layers, simultaneous coating by a T-die that can discharge two or more layers at the same time, sequential coating that coats one layer and then coats the next layer, and drying after coating one layer is considered. Various methods such as the method of coating the next layer, the method of coating the next layer after finishing the thin film of one layer, or adding a thermoplastic layer to heat lamination for multilayering, etc., can be appropriately used in this patent. Various coating methods and multilayering methods.

＜Laminates＞ The laminate of the present invention includes the above-mentioned polyimide film and an inorganic substrate. In the aforementioned laminate, when the polyimide film is composed of two or more layers, at least one layer only needs to contain the polyimide of the present invention. Moreover, in addition to the polyimide film, a transparent high heat-resistant film other than the polyimide film may be laminated.

As a transparent high heat-resistant film, PET, PEN, PVC, acrylic, polystyrene, polycarbonate, etc. are mentioned. Transparent high heat resistant film can be used on either side of the polyimide film.

A silane coupling agent layer, an adhesive layer, an adhesive layer, etc. may be further included between the polyimide film and the inorganic substrate. In addition, the surface of the polyimide film may contain a wiring layer, a conductive film layer, a metal layer, and the like.

＜Inorganic substrate＞ As the above-mentioned inorganic substrate, as long as it is a plate-shaped object that can be used as a substrate containing inorganic substances, for example: those mainly composed of glass plates, ceramic plates, semiconductor wafers, metals, etc., and such glass plates, ceramics, etc. Boards, semiconductor wafers, and metal composites are those that are laminated, those that are dispersed therein, those that contain these fibers, etc.

The aforementioned glass plate includes quartz glass, high silicate glass (96% silica), soda lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (PYREX (registered trademark)), borosilicate glass (alkali-free), boric acid glass (microsheet), aluminosilicate glass, etc. Among them, those with a linear expansion coefficient of 5 ppm/K or less are desirable, and if they are commercially available, "Corning (registered trademark) 7059" and "Corning (registered trademark) 1737" manufactured by Corning Co., Ltd., which are glasses for liquid crystals, are desirable. ", "EAGLE", "AN100" manufactured by Asahi Glass Co., Ltd., "OA10, OA11G" manufactured by NEC Glass Co., Ltd., "AF32" manufactured by SCHOTT Corporation, etc.

The aforementioned semiconductor wafer is not particularly limited, and examples thereof include silicon wafers, germanium, silicon-germanium, gallium-arsenic, aluminum-gallium-indium, nitrogen-phosphorus-arsenic-antimony, SiC, InP (indium-phosphorus), InGaAs, GaInNAs, LT, LN, ZnO (zinc oxide) or CdTe (cadmium tellurium), ZnSe (zinc selenide) and other wafers. Among them, the wafer used is preferably a silicon wafer, especially a mirror-polished silicon wafer with a size of 8 inches or more.

The aforementioned metals include single-element metals such as W, Mo, Pt, Fe, Ni, and Au, as well as Inconel, monel, nimonic, carbon copper, and Fe-Ni-based constants. Alloys such as fan alloys, super constant fan alloys, etc. In addition, these metals also include multilayer metal plates in which other metal layers and ceramic layers are added. In this case, Cu, Al, etc. may also be used for the main metal layer if the overall coefficient of linear expansion (CTE) with the additional layer is low. The metal used as the additional metal layer is not limited as long as it can securely adhere to the high heat-resistant film and has characteristics such as no diffusion, good chemical resistance, and heat resistance. Examples include: Cr, Ni, TiN, Mo, Cu, etc. are given as suitable examples.

The ceramic plate in the present invention includes Al ₂ O ₃ , mullite, AlN, SiC, crystallized glass, cordierite, spodumene, Pb-BSG+CaZrO ₃ +Al ₂ O ₃ , Crystallized glass+Al ₂ O ₃ , Crystallized Ca-BSG, BSG+Quartz, BSG+ Quartz, BSG+ Al ₂ O ₃ , Pb-BSG+Al ₂ O ₃ , Glass-ceramic, glass-ceramic (ZERODUR) materials and other substrate ceramics.

The planar portion of the aforementioned inorganic substrate is preferably sufficiently flat. Specifically, the P-V value of the surface roughness is preferably less than 50 nm, more preferably less than 20 nm, and even more preferably less than 5 nm. If it is rougher than this, the peel strength between the polyimide film layer and the inorganic substrate may be insufficient.

The thickness of the above-mentioned inorganic substrate is not particularly limited, but from the viewpoint of handling, the thickness is preferably 10 mm or less, more preferably 3 mm or less, and still more preferably 1.3 mm or less. The lower limit of the thickness is not particularly limited, but is preferably at least 0.07 mm, more preferably at least 0.15 mm, and even more preferably at least 0.3 mm. If it is too thin, it will be easily damaged and difficult to handle. And if it is too thick, it becomes heavy and difficult to handle.

＜Formation of laminate＞ As the laminated body of this invention, what laminated|stacked the said polyimide film and the said inorganic board|substrate substantially without using an adhesive agent is preferable. When the polyimide film has a laminated structure of two or more layers, it is preferable to include the aforementioned first polyimide film in contact with the inorganic substrate and the aforementioned first polyimide film layer that is not in contact with the inorganic substrate but is in contact with the aforementioned first polyimide film. Adjacent to the second polyimide film layer. The aforementioned second polyimide film may further have a multilayer structure. Also, in the thickness direction of the laminate, both ends are constituted by inorganic substrates (for example, inorganic substrate/first polyimide film/second polyimide film/first polyimide film/inorganic substrate ) is fine. In this case, substantially no adhesive is used between the polyimide film and the inorganic substrate at both ends.

The formation of the laminate is either a method of laminating the polyimide film on the inorganic substrate after fabrication, or a method of forming the polyimide film on the inorganic substrate directly or through another layer. When forming through other layers, it is preferable to interpose easily peelable layers, such as a silane coupling agent layer, in between. In addition, in order to control the peeling force to an appropriate level, surface treatment may be performed on the inorganic substrate.

The shape of the laminate is not particularly limited, and may be square or rectangular. It is preferably rectangular, and the length of the long side is preferably at least 300 mm, more preferably at least 500 mm, and even more preferably at least 1000 mm. The upper limit is not particularly limited, and it is expected that substrates of industrially used sizes and materials can be replaced. As long as it is 20000 mm or less, it is sufficient, and 10000 mm or less is fine.

In the laminate of the present invention, the amount of warpage when heated at 300° C. is preferably 10 mm or less. In order to make heat resistance good, it is more preferably 8 mm or less, still more preferably 6 mm or less. The lower limit of the amount of warpage is not particularly limited, and it is sufficient industrially if it is 0.01 mm or more, and 0.1 mm or more is also acceptable.

＜Adhesive＞ It is preferable that the adhesive layer is not substantially interposed between the inorganic substrate and the polyimide film. Here, the adhesive layer in the present invention means that the Si (silicon) component is less than 10% (less than 10% by mass) in terms of mass ratio. In addition, the term “not used substantially” means that the thickness of the adhesive layer between the inorganic substrate and the polyimide film is preferably 0.4 μm or less, more preferably 0.1 μm or less, and even more preferably 0.05 μm or less. μm or less, particularly preferably 0.03 μm or less, most preferably 0 μm.

＜Silane coupling agent (SCA)＞ In the laminate, a layer having a silane coupling agent between the polyimide film and the inorganic substrate is preferable. In the present invention, the so-called silane coupling agent refers to a compound containing 10% by mass or more of Si (silicon) component. More preferably, it has an alkoxy group in the structure. Also, it is desirable not to have a methyl group. By using the silane coupling agent layer, the intermediate layer between the polyimide film and the inorganic substrate can be thinned, so the following effects can be exhibited: there are few outgassing components during heating, and it is not easy to dissolve in the wet process, even if There is only a small amount of dissolution. Among the silane coupling agents, in order to improve heat resistance, it is preferable to contain a large amount of silicon oxide component, and it is particularly preferable to have heat resistance at a temperature of about 400°C. The thickness of the silane coupling agent layer is preferably less than 0.2 μm. The range used as a flexible electronic element is preferably 100 nm or less (0.1 μm or less), more desirably 50 nm or less, and still more desirably 10 nm. If produced by a general method, it is about 0.10 μm or less. In addition, it can also be used below 5nm in the process where very little silane coupling agent is expected. If it is 1 nm or less, there is a possibility that the peeling strength will decrease or a partially unattached part will appear, so it is desirably 1 nm or more.

The silane coupling agent in the present invention is not particularly limited, and preferably has an amino group or an epoxy group. Specific examples of silane coupling agents include: N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-amine N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane Oxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-cyclo Oxypropoxypropyltrimethoxysilane, 3-Glycidoxypropylmethyldiethoxysilane, 3-Glycidoxypropyltriethoxysilane, Vinyltrichlorosilane, Vinyl Trimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-epoxycyclohexyltrimethoxysilane, Propoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane Methoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane Oxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3 -Aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3- Mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatopropyltriethoxysilane, ginseng-(3-trimethoxysilylpropyl)isocyanurate , Chloromethylphenethyltrimethoxysilane, chloromethyltrimethoxysilane, etc. Among them, the preferred ones include: N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl Trimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane Silane, 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropyl Oxypropyltrimethoxysilane, 3-Glycidoxypropylmethyldiethoxysilane, 3-Glycidoxypropyltriethoxysilane, Aminophenyltrimethoxysilane, Aminophenethyltrimethoxysilane, aminoanilinomethylphenethyltrimethoxysilane, etc. When heat resistance is required in the manufacturing process, it is desirable to link Si and amine groups with aromatics.

The peel strength between the polyimide film and the aforementioned inorganic substrate must be 0.3 N/cm or less. Thereby, after the element is formed on the polyimide film, the polyimide film and the inorganic substrate can be detached very easily. Therefore, it is possible to manufacture an element connected body which can be mass-produced, and it is easy to manufacture a flexible electronic element. The aforementioned peel strength is preferably 0.25 N/cm or less, more preferably 0.2 N/cm or less, further preferably 0.15 N/cm or less, particularly preferably 0.12 N/cm or less. Also, it is preferably 0.03 N/cm or more. From the standpoint that the laminate does not peel off when the device is formed on the polyimide film, it is more preferably at least 0.06 N/cm, further preferably at least 0.08 N/cm, and particularly preferably at least 0.1 N/cm. The above-mentioned peel strength is a value (initial peel strength) of the laminate after bonding the polyimide film and the above-mentioned inorganic substrate and heat-treating at 100° C. for 10 minutes in an air atmosphere. In addition, when the laminate is further heat-treated at 300° C. for 1 hour under a nitrogen atmosphere, the peel strength is also preferably within the aforementioned range (peel strength after heat treatment at 300° C.).

The laminate of the present invention can be produced, for example, by the following procedures. At least one side of the inorganic substrate is treated with a silane coupling agent in advance, and the polyimide film is superimposed on the surface treated with the silane coupling agent, and both are laminated under pressure to obtain a laminate. Furthermore, at least one side of the polyimide film is treated with a silane coupling agent in advance, and the surface treated with the silane coupling agent is superimposed on the inorganic substrate, and both are laminated under pressure to obtain a laminate. Also, when the polyimide film has a laminated structure of two or more layers, it is preferable to laminate the first polyimide film on the inorganic substrate. As the pressurization method, general pressurization or lamination in the air, or pressurization or lamination in a vacuum are mentioned. In order to obtain a stable peel strength across the board, it is desirable to use a large-sized laminate ( For example, more than 200mm) are laminated in the atmosphere. On the other hand, in the case of a small-sized laminate of about 200 mm or less, it is preferable to pressurize in a vacuum. The vacuum degree is sufficient as that formed by a general oil rotary pump, and it is sufficient as long as it is below 10 Torr. The preferred pressure is 1 MPa to 20 MPa, more preferably 3 MPa to 10 MPa. If the pressure is high, there is a possibility that the substrate may be damaged, and if the pressure is low, there may be a non-adhesive part. A preferable temperature is from 90° C. to 500° C., more preferably from 100° C. to 400° C. If the temperature is high, the film may be damaged, and if the temperature is low, the adhesion may be weak.

＜Manufacturing method of flexible electronic components＞ The manufacturing method of the flexible electronic device of the present invention includes the step of forming the electronic device on the polyimide film surface of the laminate of the present invention, and the step of peeling off the aforementioned inorganic substrate. In this way, a flexible electronic element in which the electronic element is formed on the surface of the polyimide film can be manufactured.

Therefore, the flexible electronic component of the present invention includes the polyimide film of the present invention and electronic components formed on the polyimide film.

If the above-mentioned laminate is used, it is possible to easily manufacture flexible electronic elements using existing electronic element manufacturing equipment and processes. Specifically, by forming an electronic element on the polyimide film of the laminate, and peeling off the laminate together with the polyimide film, a flexible electronic element can be produced.

In this specification, the so-called electronic component refers to a wiring substrate with a single-sided, double-sided or multi-layer structure that carries electrical wiring, and includes active components such as transistors and diodes, and passive components such as resistors, capacitors, and inductors. Electronic circuits, other sensor components such as sensing pressure, temperature, light, humidity, etc., biological sensor components, light-emitting components, liquid crystal display, electrophoretic display, self-luminous display, etc. Image display components, wireless/wired communication components , calculation components, memory components, MEMS components, solar cells, thin film transistors, etc.

In addition, the wiring board also includes electrodes penetrating polyimide, which function as an interposer. By roughly penetrating through, the step of forming a penetrating electrode can be largely omitted after the inorganic substrate is peeled off. A known technique can be used to form the through hole. For example, through-holes can be formed in polyimide films by UV nanolaser. Then, for example, there is a method of filling the through holes with conductive metal by applying a predetermined method used for through holes of double-sided printed wiring boards or through holes of multilayer printed wiring boards, and then responding to It is necessary to form the wiring pattern with metal.

The polyimide film can be bonded to the inorganic substrate after opening the through-electrodes as described above. The through electrodes may also be produced after laminating the inorganic substrate and the polyimide film. This point may be metallized after the polyimide membrane is pierced, but it is also possible to metallize this point without penetrating through to the surface on the opposite side by opening a hole from one side of the polyimide film.

<Procedure for peeling off the inorganic substrate> The method of manufacturing a flexible electronic device according to the present invention includes a step of peeling off the inorganic substrate after forming the electronic device on the polyimide film surface of the laminate. When peeling the aforementioned inorganic substrate, in addition to peeling at the interface between the polyimide film and the inorganic substrate, one or more layers of the polyimide film composed of two or more layers may be peeled together, or the The aforementioned inorganic substrate is peeled together with other arbitrary layers.

In the case of peeling the interface between the polyimide film and the inorganic substrate, that is, the method of peeling the polyimide film with the component from the inorganic substrate is not particularly limited, and the method of rolling it up from the end with tweezers or the like can be used. , Form a cut in the polyimide film, stick an adhesive tape on one side of the cut part and roll it up from the tape part, vacuum absorb one side of the cut part of the polyimide film and then The method of rolling up from this part, etc. In addition, if a curl with a small curvature occurs at the cut portion of the polyimide film during peeling, stress will be applied to the element at that portion, and the element may be damaged. Therefore, it is desirable to peel in a state where the curvature is extremely large. For example, it is desired to roll up while being wound on a roll with a large curvature, or to roll it up using a machine in which a roll with a large curvature is positioned at the peeling part.

As a method of forming a cut on the aforementioned polyimide film, there are: a method of cutting the polyimide film with a cutting tool such as a knife, and cutting the polyimide film by scanning the laser and the laminate against each other. A method of amine film, a method of cutting a polyimide film by scanning a water jet against a laminate, a method of cutting a polyimide film by slightly cutting into a glass layer with a semiconductor wafer dicing device, etc. , but the method is not particularly limited. For example, when adopting the above-mentioned method, a technique of superimposing ultrasonic waves on a cutting tool, a technique of giving a back and forth motion or a vertical motion, etc. to improve the cutting performance may also be appropriately adopted.

In addition, it is also useful to attach another reinforcing base material to the peeled part and then peel it off together with the reinforcing base material. When the peeled flexible electronic element is the back plate of the display element, the front plate of the display element can also be pasted in advance, integrated on the inorganic substrate, and then both are peeled off simultaneously to obtain a flexible display element.

Also, when the inorganic substrate and one or more polyimide films composed of two or more layers are peeled together, the peeling force at the interface of the polyimide film composed of two or more layers can be adjusted in advance to be smaller than that of the inorganic substrate. The peeling force at the interface was peeled off in the same manner as the aforementioned method. The adjustment of the peeling force at the interface of the polyimide film can be adjusted according to the type of polyimide of each layer and the degree of imidization of the lower layer when the upper layer is coated.

When peeling the above-mentioned inorganic substrate together with other optional layers, an adhesive layer or the like having higher adhesion to the inorganic substrate and adjusted peeling force to the polyimide film is provided in advance, and the peeling is performed in the same manner as the above-mentioned method. [Example]

Although the present invention will be described in detail below using examples, the present invention is not limited to the following examples unless the gist is exceeded. In addition, each physical property value in a synthesis example and an Example was measured by the following method.

＜Thickness measurement of polyimide film＞ The thickness of the film was measured using a micrometer (manufactured by Feinpruf, Miritoron 1245D). Also, the same measurement was performed three times, and the arithmetic mean thereof was adopted.

＜Total light transmittance＞ The total light transmittance (TT) of the film was measured using HAZEMETER (NDH5000, manufactured by Nippon Denshoku Co., Ltd.). As the light source, D65 lump was used. Also, the same measurement was performed three times, and the arithmetic mean thereof was adopted.

＜Haze＞ The haze of the film was measured using HAZEMETER (NDH5000, manufactured by Nippon Denshoku Co., Ltd.). As the light source, D65 lump was used. Also, the same measurement was performed three times, and the arithmetic mean thereof was adopted.

＜Yellow Index＞ Using a colorimeter (ZE6000, manufactured by Nippon Denshoku Co., Ltd.) and a C2 light source, the tristimulus value XYZ value of the film was measured according to ASTM D1925, and the yellowness index (YI) was calculated by the following formula. Also, the same measurement was performed three times, and the arithmetic mean thereof was adopted.

YI=100×(1.28X-1.06Z)/Y ＜Glass transition temperature (Tg), coefficient of linear expansion (CTE)＞ The measurement was performed using TMA (TMA4000S, BRUKER AXIS). The film was cut into short pieces with a width of 15 mm x a length of 2 mm, and it was set in an apparatus under conditions of 10 mm between chucks and a load of 5 gf. Under an argon atmosphere, the temperature was raised to 250° C. at a rate of 20° C./minute, and then lowered to 30° C. at a rate of 5° C./minute. Thereafter, the temperature was raised to a temperature (Td1-20°C) at which thermal decomposition did not occur at a rate of 10°C/min. The CTE was calculated from the slope in the range of 200° C. to 50° C. when the temperature was lowered, and the inflection point when the temperature was raised for the second time was taken as Tg.

＜Tensile modulus, tensile strength, elongation, tensile product＞ Using TENSILON (Autograph AG-IS, Shimadzu Corporation), the test was carried out as follows. The film was cut into a short piece of 5 mm x 50 mm in length in the traveling direction (MD direction) at the time of coating, and this was used as a test piece. The two ends of the short film were clamped by the chuck of Air Jaw for 30 mm. At room temperature, the tensile modulus of elasticity, tensile strength at break and elongation at break in the MD direction were obtained under the condition of a tensile speed of 50 mm/min. The tensile elastic coefficient is obtained from the initial elastic slope of the strain-stress curve. The measurement system is carried out with N=5 for each level, the maximum and minimum values are excluded, and the average value of 3 points is used as the data. The product of the tensile strength at break and the elongation at break was taken as the tensile product.

< ¹ HNMR measurement of silsesquioxane compound which has an acid anhydride group> Using each sample, ¹ HNMR measurement was performed under the following conditions. Device: DPX400 manufactured by Bruker BioSpin (Examples 1-2) or 400MR manufactured by Agilent (Examples 3-9) Solvent: Deuterated chloroform (CDCl ₃ ) (Examples 1-2) or deuterated DMSO (DMSO-d ₆ ) (Examples 3 to 9) Sample concentration: 3mg/1mL Measurement temperature: room temperature (24°C) Resonance frequency: 400MHz Accumulated times: 32 times

[Synthesis Example 1-1: Synthesis of Thiol Group-Containing Silsesquioxane Compound 1] Add 11.8g (60.0mmol) of 3-mercaptopropyltrimethoxysilane and 2.72g of methyltrimethoxysilane ( 20.0mmol) ([the number of moles of component (a2)]/[the total number of moles of components (a1) and components (a2)]=0.25), 1.9g of ion-exchanged water ([the amount of water used for hydrolysis reaction Mole number]/[total mole number of alkoxy groups contained in components (a1) and (a2)] (mole ratio)=0.45), 1.0 g of cation exchange resin, hydrolyzed at room temperature React for 30 minutes. After the reaction, the cation exchange resin was filtered and diluted with 5 g of ethylene glycol dimethyl ether (DMG) to obtain a hydrolyzate solution.

Then, a 25% aqueous solution of 9 g of DMG and 0.05 g of tetramethylammonium hydroxide was added to another reaction vessel, and heated to 80°C. Here it took 2 hours and 30 minutes to drop in the previous hydrolyzate solution. During the dropping, tetramethylammonium hydroxide was dissolved, and the reaction liquid became clear. After dripping, it was made to react at 80 degreeC for 15 minutes, and then cooled to 25 degreeC. Here, 0.5 g of cation exchange resin was added, and stirred at room temperature for 4 hours. During stirring, tetramethylammonium hydroxide was adsorbed, and the reaction solution became clear. By filtering off the cation exchange resin, a solution of silsesquioxane containing thiol groups (average number of thiol groups per molecule=6) was obtained. Toluene was added and heated to 70° C. under reduced pressure to distill off methanol, water, and a part of toluene generated by hydrolysis. Toluene was appropriately added to adjust the final solid content concentration to 72%.

[Synthesis Example 1-2: Synthesis of Thiol Group-Containing Silsesquioxane Compound 2] 8.83 g (45.0 mmol) of 3-mercaptopropyltrimethoxysilane and 5.44 g (40.0 mmol) of methyltrimethoxysilane ([the number of moles of component (a2)]/[component (a1) and component The total number of moles of (a2)]=0.47), ion-exchanged water is 2.0g ([the number of moles of water used for hydrolysis reaction]/[the total number of alkoxy groups contained in components (a1), (a2) molar number] (molar ratio) = 0.45), and synthesized in the same manner as in Synthesis Example 1-1. The average number of thiol groups per molecule of the obtained thiol group-containing silsesquioxane was 4.5, and the final solid content concentration was 72% by mass.

[Synthesis Example 1-3: Synthesis of Thiol Group-Containing Silsesquioxane Compound 3] 4.91 g (25.0 mmol) of 3-mercaptopropyltrimethoxysilane and 6.81 g (50.0 mmol) of methyltrimethoxysilane ([the number of moles of component (a2)]/[component (a1) and component The total number of moles of (a2)]=0.67), ion-exchanged water is 1.8g ([the number of moles of water used for hydrolysis reaction]/[the total number of alkoxy groups contained in components (a1), (a2) molar number] (molar ratio) = 0.45), and synthesized in the same manner as in Synthesis Example 1-1. The average number of thiol groups per molecule of the obtained thiol group-containing silsesquioxane was 2.5, and the final solid content concentration was 72% by mass.

[Synthesis Example 2-1: Synthesis of silsesquioxane SQ1 having an acid anhydride group] Put the following thiol group-containing silsesquioxane solution (manufactured by Arakawa Chemical Industry Co., Ltd., Compoceran SQ-109) 10g (thiol group content: 16.7mmol), and norbornene acid anhydride 2.74g (16.7mmol) The reaction container was irradiated with ultraviolet light (Spot Cure SP-11, manufactured by USHIO) for 20 minutes while stirring, thereby obtaining silsesquioxane SQ1 having an acid anhydride group as a colorless and transparent solution. By NMR and IR measurements, it was confirmed that the thiol group and norbornene had reacted. The obtained solution was filtered with a PTFE filter (pore diameter: 10 μm), and used for the synthesis of the polyamic acid solution described later (the same applies to SQ3 to SQ9).

Compoceran SQ-109: Condensate of methyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane, molar ratio (former/(former+latter))=2/8, solvent PGMEA, solid content concentration 25 mass %.

In addition, the said molar ratio and the average number of thiol groups per molecule were calculated as follows. In ¹ HNMR measurement of Compoceran SQ-109, integration from protons derived from methyl groups (around δ=0.0 to 0.2, 3H) and protons derived from propylthiol groups (around δ=0.2 to 0.8, 2H) Ratio, calculate the molar ratio of methyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane. The average number of thiol groups per molecule is based on the ratio of the above-mentioned thiol groups to methyl groups, the molecular weight of each structural unit (SiO _1.5 Me=67.1, SiO _1.5 C ₃ H ₆ SH=127.2), the thiol groups of the solution Equivalent (600g/eq.), solid content concentration 25% by mass calculation.

For reference, the results of the NMR measurement are shown in FIGS. 1 to 4 . Figure 1 shows ^{the 1} HNMR (CDCl ₃ ) spectrum of SQ-109 (PGMEA solution), Figure 2 shows ^{the 1} HNMR (CDCl ₃ ) spectrum of PGMEA, and Figure 3 shows ^{the 1} HNMR (CDCl ₃ ) spectrum of norbornene anhydride , ^{the 1} HNMR (CDCl ₃ ) spectrum of the reaction mixture after the reaction is shown in FIG. 4 . In FIG. 4 , the peak (δ=6.3, etc.) derived from the double bond of norbornene acid anhydride disappeared, and it was considered that the reaction between the thiol group and the double bond had progressed.

[Synthesis Example 2-2: Synthesis of silsesquioxane SQ2 having an acid anhydride group] Thiol-containing silsesquioxane solution (manufactured by Arakawa Chemical Industry Co., Ltd., Compoceran SQ-109) 10g (16.7mmol of thiol group), 2.74g (16.7mmol) of norcamphenic anhydride, ferric chloride ( III) 1 mg was put into a reaction vessel and stirred for 10 minutes to obtain silsesquioxane SQ2 having an acid anhydride group as a pale yellow solution (the yellow coloration is believed to be derived from ferric chloride). By NMR and IR measurements, it was confirmed that the thiol group and norbornene had reacted.

For reference, the ¹ HNMR (CDCl ₃ ) spectrum of the reaction mixture after the reaction is shown in FIG. 5 as a result of NMR measurement. In FIG. 5 , the peak (δ=6.3, etc.) derived from the double bond of norbornene acid anhydride disappeared, and it was considered that the reaction between the thiol group and the double bond had progressed.

[Synthesis Example 2-3: Synthesis of silsesquioxane SQ3 having an acid anhydride group] Put 20 g of the solution of the thiol group-containing silsesquioxane compound 1 obtained in Synthesis Example 1-1 (97.0 mmol of thiol group), 15.9 g (97.0 mmol) of norbornene anhydride, and 10.0 g of PGMEA into The reaction container was irradiated with ultraviolet light (Spot Cure SP-11, manufactured by USHIO Co., Ltd.) for 20 minutes while stirring, thereby obtaining silsesquioxane SQ3 having an acid anhydride group as a colorless and transparent solution. By NMR and IR measurements, it was confirmed that the thiol group and norbornene had reacted.

[Synthesis Example 2-4: Synthesis of silsesquioxane SQ4 having an acid anhydride group] Put 20 g of the solution of the thiol group-containing silsesquioxane compound 2 obtained in Synthesis Example 1-2 (77.9 mmol of thiol group), 12.8 g (77.9 mmol) of norbornene anhydride, and 10.0 g of PGMEA into The reaction container was irradiated with ultraviolet light (Spot Cure SP-11, manufactured by USHIO Co., Ltd.) for 20 minutes while stirring, thereby obtaining silsesquioxane SQ4 having an acid anhydride group as a colorless and transparent solution. By NMR and IR measurements, it was confirmed that the thiol group and norbornene had reacted.

[Synthesis Example 2-5: Synthesis of silsesquioxane SQ5 having an acid anhydride group] 20 g (thiol group content 54.5 mmol) of the thiol group-containing silsesquioxane compound 3 obtained in Synthesis Example 1-3, 5-norbornene-2,3-dicarboxylic anhydride 8.95 g (54.5 mmol) and 10.0 g of PGMEA were placed in a reaction vessel, and irradiated with ultraviolet light (Spot Cure SP-11, manufactured by USHIO Co., Ltd.) for 20 minutes while stirring, thereby obtaining silsesquioxane SQ5 having an acid anhydride group as a colorless transparent solution . By NMR and IR measurements, it was confirmed that the thiol group had reacted with 5-norbornene-2,3-dicarboxylic anhydride.

[Synthesis Example 2-6: Synthesis of silsesquioxane SQ6 having an acid anhydride group] Put 6 g of thiol group-containing trialkoxysilane solution (manufactured by Arakawa Chemical Industry Co., Ltd., Compoceran SQ-109) (10.0 mmol of thiol group), and 1.40 g (10.0 mmol) of allyl succinic anhydride into the reaction The container was irradiated with ultraviolet light (Spot Cure SP-11, manufactured by USHIO Co., Ltd.) for 20 minutes while stirring, thereby obtaining silsesquioxane SQ6 having an acid anhydride group as a colorless and transparent solution. By NMR and IR measurements, it was confirmed that the thiol group had reacted with allyl succinic anhydride.

[Synthesis Example 2-7: Synthesis of silsesquioxane SQ7 having an acid anhydride group] 6 g of a trialkoxysilane solution containing thiol groups (manufactured by Arakawa Chemical Industry Co., Ltd., Compoceran SQ-109) (10.0 mmol of thiol groups), exo-3,6-epoxy-1,2,3 1.66 g (10.0 mmol) of 6-tetrahydrophthalic anhydride was placed in a reaction vessel, and irradiated with ultraviolet light (Spot Cure SP-11, manufactured by USHIO Co., Ltd.) Based on silsesquioxane SQ7. By NMR and IR measurements, it was confirmed that the thiol group had reacted with exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride.

[Synthesis Example 2-8: Synthesis of silsesquioxane SQ8 having an acid anhydride group] 3 g of trialkoxysilane solution containing thiol group (manufactured by Arakawa Chemical Industry Co., Ltd., Compoceran SQ-109) (5.0 mmol of thiol group), 5,6-dihydro-1,4-dithiene -2,3-dicarboxylic anhydride (5,6-Dihydro-1,4-dithiin-2,3-dicarboxylic Anhydride) 0.94g (5.0mmol), γ-butyrolactone (5mL) into the reaction vessel, while stirring While irradiating with ultraviolet light (Spot Cure SP-11, manufactured by USHIO Corporation) for 20 minutes, silsesquioxane SQ8 having an acid anhydride group was obtained as a colorless and transparent solution. By NMR and IR measurements, it was confirmed that the thiol group had reacted with 5,6-dihydro-1,4-dithiene-2,3-dicarboxylic anhydride.

[Synthesis Example 2-9: Synthesis of silsesquioxane SQ9 having an acid anhydride group] Put 6 g of thiol group-containing trialkoxysilane solution (manufactured by Arakawa Chemical Industry Co., Ltd., Compoceran SQ-109) (10.0 mmol of thiol group) into the reaction vessel, and slowly add triphenylene trichloride while stirring Acid anhydride (trimellitic anhydride chloride) 2.10 g (10.0 mmol). By stirring at room temperature for 24 hours, silsesquioxane SQ9 having an acid anhydride group was obtained as a colorless and transparent solution. By NMR and IR measurements, it was confirmed that the thiol group and the chloroyl group had reacted.

[Comparative synthesis example 2-1: Synthesis of terminal dicarboxylic anhydride silsesquioxane SQN1 (without thioether moiety)] Silsesquioxane SQN1 having a structure represented by the following chemical formula and not containing a thioether moiety was synthesized by the method described in Example 1 of International Publication WO2010/095329A1.

[比較合成例2-2：末端二羧酸酐矽倍半氧烷SQN2(不含硫醚部)的合成] 藉由國際公開WO2010/095329A1號公報的實施例2記載的方法，合成具有下述化學式表示的結構且不含硫醚部的矽倍半氧烷SQN2。

[Comparative Synthesis Example 2-2: Synthesis of terminal dicarboxylic acid anhydride silsesquioxane SQN2 (without thioether moiety]] According to the method described in Example 2 of International Publication WO2010/095329A1, the compound having the following chemical formula was synthesized: The structure shown and the silsesquioxane SQN2 without the thioether moiety.

[實施例A：聚醯胺酸溶液A的合成] 一邊使氮氣通過具備氮氣導入管、攪拌槳的反應器，一邊加入1,2,3,4-環丁烷四甲酸二酐(CBDA，5.88g)、4,4’-二胺基-2,2’-雙(三氟甲基)聯苯(TFMB，9.74g)、SQ1溶液(0.655g)，溶解於N,N-二甲基乙醯胺(DMAc，125.0g)後，在25℃下攪拌24小時，藉此得到聚醯胺酸溶液A(CBDA/SQ1/TFMB之莫耳比=0.985/0.015/1.00)。此處，SQ1之莫耳比，係以酸酐基每2價為基準所算出的值，具體係以源自矽倍半氧烷化合物A的單元結構之總莫耳數除以前述二羧酸酐基的總數再乘以2倍所得的數值進行計算(關於以下的莫耳比亦相同)。

[Example A: Synthesis of Polyamic Acid Solution A] 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA, 5.88 g), 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB, 9.74g), SQ1 solution (0.655g), dissolved in N,N-dimethylethyl After amide (DMAc, 125.0 g), it was stirred at 25° C. for 24 hours to obtain polyamide acid solution A (mole ratio of CBDA/SQ1/TFMB=0.985/0.015/1.00). Here, the molar ratio of SQ1 is a value calculated on the basis of an acid anhydride group per 2 valences, specifically, the total molar number of the unit structure derived from the silsesquioxane compound A is divided by the aforementioned dicarboxylic anhydride group Calculated by multiplying the total value by 2 times (the same applies to the following mol ratios).

[Example B: Synthesis of Polyamic Acid Solution B] 1,2,3,4-Cyclobutanetetracarboxylic dianhydride (CBDA, 5.88g) and 4,4'-diaminobenzamide were added while passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade Aminobenzene (DABA, 6.92g), SQ1 solution (0.655g), dissolved in N,N-dimethylacetamide (DMAc, 133.7g), stirred at 25°C for 24 hours, thereby obtaining polyamide Acid solution B (molar ratio of CBDA/SQ1/DABA=0.985/0.015/1.00).

[Example Ca: Synthesis of Polyamic Acid Solution Ca] While passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 4.88g), SQ1 solution (0.328g), dissolved in N,N-dimethylacetamide (DMAc, 67.0g), and stirred at 25°C for 24 hours to obtain polyamide Amino acid solution Ca (molar ratio of PMDA/SQ1/TFMB=0.985/0.015/1.00).

[Example Cb: Synthesis of Polyamic Acid Solution Cb] While passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 4.90g), SQ3 solution (0.227g), dissolved in N-methyl-2-pyrrolidone (NMP, 66.0g), stirred at 25°C for 24 hours, thereby obtaining polyamide Amino acid solution Cb (mole ratio of PMDA/SQ3/TFMB=0.98/0.02/1.00).

[Example Cc: Synthesis of Polyamic Acid Solution Cc] While passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 4.90g), SQ4 solution (0.258g), dissolved in N-methyl-2-pyrrolidone (NMP, 66.0g), and stirred at 25°C for 24 hours to obtain polyamide Amino acid solution Cc (molar ratio of PMDA/SQ4/TFMB=0.98/0.02/1.00).

[Example Cd: Synthesis of Polyamic Acid Solution Cd] While passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 4.90g), SQ5 solution (0.325g), dissolved in N-methyl-2-pyrrolidone (NMP, 66.0g), and stirred at 25°C for 24 hours to obtain polyamide Amino acid solution Cd (molar ratio of PMDA/SQ5/TFMB=0.98/0.02/1.00).

[Example Ce: Synthesis of Polyamic Acid Solution Ce] While passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 4.90g), SQ9 solution (0.354g), dissolved in N-methyl-2-pyrrolidone (NMP, 66.0g), and stirred at 25°C for 24 hours, thereby obtaining polyamide Amino acid solution Ce (molar ratio of PMDA/SQ9/TFMB=0.985/0.015/1.00).

[Example D: Synthesis of Polyamic Acid Solution D] While making nitrogen pass through a reactor equipped with a nitrogen introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diaminobenzamide benzene (DABA, 3.47 g), SQ1 solution (0.328g), dissolved in N,N-dimethylacetamide (DMAc, 63.0g), stirred at 25°C for 24 hours, thereby obtaining polyamide acid solution D (PMDA/SQ1/DABA Mole ratio=0.985/0.015/1.00).

[Comparative Example A1: Synthesis of Polyamic Acid Solution A1] 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA, 19.6g), 4,4'-diamino-2, 2'-bis(trifluoromethyl)biphenyl (TFMB, 32.3g), dissolved in N,N-dimethylacetamide (DMAc, 279.0g), stirred at 25°C for 24 hours, thereby obtaining Polyamide acid solution A1 (CBDA/TFMB molar ratio=1.00/1.00).

[Comparative Example B1: Synthesis of Polyamic Acid Solution B1] 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA, 3.98g) and 4,4'-diaminobenzoyl Aminobenzene (DABA, 4.58g) was dissolved in N,N-dimethylacetamide (DMAc, 76.0g) and stirred at 25°C for 24 hours to obtain polyamide acid solution B1 (CBDA/DABA Mole ratio=1.00/1.00).

[Example B2: Synthesis of Polyamic Acid Solution B2] 1,2,3,4-Cyclobutanetetracarboxylic dianhydride (CBDA, 2.94g) and 4,4'-diaminobenzamide were added while passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade Aminobenzene (DABA, 3.54g), SQ1 solution (1.00g), dissolved in N,N-dimethylacetamide (DMAc, 90g), stirred at 25°C for 24 hours, thereby obtaining polyamic acid Solution B2 (molar ratio of CBDA/SQ1/DABA=0.955/0.045/1.00).

[Comparative Example B4: Synthesis of Polyamic Acid Solution B4] 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA, 3.98g) and 4,4'-diaminobenzoyl Aminobenzene (DABA, 4.55g) was dissolved in N,N-dimethylacetamide (DMAc, 76.0g), and stirred at 25°C for 24 hours. Thereafter, SQ-109 (0.546 g) was added and stirred for 24 hours to obtain polyamic acid solution B4 (molar ratio of CBDA/DABA/SQ-109=1.00/1.00/0.01).

[Comparative Example B5: Synthesis of Polyamic Acid Solution B5] 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA, 3.98g) and 4,4'-diaminobenzoyl Aminobenzene (DABA, 4.55g) was dissolved in N,N-dimethylacetamide (DMAc, 76.0g), and stirred at 25°C for 24 hours. Thereafter, SQ-109 (8.19 g) was added, followed by stirring for 24 hours to obtain polyamic acid solution B5 (molar ratio of CBDA/DABA/SQ-109=1.00/1.00/0.15).

[Comparative Example B6: Synthesis of Polyamic Acid Solution B6] 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA, 3.98g) and 4,4'-diaminobenzoyl Aminobenzene (DABA, 4.55g) was dissolved in N,N-dimethylacetamide (DMAc, 76.0g), and stirred at 25°C for 24 hours. Thereafter, SQ-109 (27.3 g) was added, followed by stirring for 24 hours to obtain polyamic acid solution B6 (the molar ratio of CBDA/DABA/SQ-109=1.00/1.00/0.50).

[Comparative Example C1: Synthesis of Polyamic Acid Solution C1] Add pyromellitic dianhydride (PMDA, 6.54 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 9.61g), dissolved in N,N-dimethylacetamide (DMAc, 164.0g), stirred at 25°C for 24 hours, thereby obtaining polyamide acid solution C1 (PMDA/ Mole ratio of TFMB=1.00/1.00).

[Comparative Example C2: Synthesis of Polyamic Acid Solution C2] While passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 4.85g), SQN1 (0.070g), dissolved in N,N-dimethylacetamide (DMAc, 67.0g), and stirred at 25°C for 24 hours to obtain polyamide Acid solution C2 (molar ratio of PMDA/SQN1/TFMB=0.99/0.01/1.00).

[Comparative Example C3: Synthesis of Polyamic Acid Solution C3] While passing nitrogen gas through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, pyromellitic dianhydride (PMDA, 3.27 g), 4,4'-diamino-2,2'-bis(trifluoromethyl ) biphenyl (TFMB, 4.85g), SQN2 (0.081g), dissolved in N,N-dimethylacetamide (DMAc, 67.0g), stirred at 25°C for 24 hours, thereby obtaining polyamide Acid solution C3 (molar ratio of PMDA/SQN2/TFMB=0.99/0.01/1.00).

[Comparative Example D1: Synthesis of Polyamic Acid Solution D1] Pyromellitic dianhydride (PMDA, 3.27g) and 4,4'-diaminobenzamide benzene (DABA, 3.41g) were added while nitrogen was passed through a reactor equipped with a nitrogen gas introduction tube and a stirring blade, After dissolving in N,N-dimethylacetamide (DMAc, 63.0g), stir at 25°C for 24 hours to obtain polyamide acid solution D1 (molar ratio of PMDA/DABA=1.00/1.00) .

The polyamic acid solutions obtained in the above examples and comparative examples were thinned by the following method, and the optical properties, thermal properties, and mechanical properties were measured.

[Example 1] The polyamic acid solution A was coated on a polyester film (A4100, manufactured by Toyobo) using a cast coater, and heated at 100° C. for 18 minutes in a nitrogen atmosphere. After cutting the resulting green film with a knife, it is peeled off from the polyester film and fixed on the frame. In a nitrogen atmosphere, heat up at a rate of 10°C/min in stages, while heating at 200°C for 10 minutes, 250°C for 10 minutes, 300°C for 10 minutes, and 350°C for 10 minutes. imidization. After standing to cool, the polyimide film was obtained by taking it out from the frame.

[Embodiments 2-5] In Example 1, except having used polyamic-acid solution B, Ca-Ce, D, and B2 instead of polyamic-acid solution A, it carried out similarly to Example 1, and obtained the polyimide film. The components used at this time and the evaluation results are shown in Table 1.

[Comparative Examples 1 to 9] In Example 1, polyamic acid solutions A1, B1, B4, B5, B6, C1, C2, C3, and D1 were used instead of polyamic acid solution A, and In the same manner as in Example 1, a polyimide film was obtained. The components used at this time and the evaluation results are shown in Table 1. [Table 1] Example 1 Example 2 Example 3a Example 3b Example 3c Example 3d Example 3e Example 4 Example 5 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative Example 5 Comparative example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 polyamide solution A B Ca Cb Cc Cd Ce D. B2 A1 B1 B4 B5 B6 C1 C2 C3 D1 Acid component into mole% CBDA 98.5 98.5 - - - - - - 95.5 100 100 100 100 100 - - - - PMDA - - 98.5 98 98 98 98.5 98.5 - - - - - - 100 99 99 100 Diamine components into mole% TFMB 100 - 100 100 100 100 100 - - 100 - - - - 100 100 100 - DABA - 100 - - - - - 100 100 - 100 100 100 100 - - - 100 Sisesquioxane into mole % SQ1 1.5 1.5 1.5 1.5 4.5 - - - - - - - - - SQ3 - - - 2 - - - - - - - - - - - SQ4 2 SQ5 2 SQ9 1.5 SQ-109 - - - - - - - 1 15 50 - - - - SQN1 - - - - - - - - - - - 1 - - SQN2 - - - - - - - - - - - - 1 - Special Notes on Solution Appearance - - - - a small amount of gel - - - cloudy cloudy - - - - membrane thickness μm 7 13 15 18 17 19 17 13 13 15 15 17 26 26 15 15 15 15 Total light transmittance % 90.3 86.2 87.4 83.4 85.2 83.8 86.2 61.3 86.0 89.8 86.2 85.9 68.7 36.2 87.2 87.0 87.1 66.7 Haze % 0.3 0.4 0.2 0.3 0.3 0.3 2.2 0.3 0.4 0.3 0.3 0.4 5.8 78.2 0.3 0.3 0.3 0.2 yellow index 1.8 5.7 7.0 18.7 14.7 17.2 9.4 102.8 8.0 3.2 6.1 7.0 48.1 131.1 9.2 9.0 9.0 90.8 Tg ℃ 392 >450 >450 >450 >450 >450 >450 >450 >450 392 >450 >450 >450 >450 >450 >450 >450 >450 CTE ppm/K 34 16 8 7 5 1 0 5 26 33 11 17 25 40 6 8 10 4 Tensile product MPa･% 1320 1337 1440 1701 1757 1000 1020 3465 1512 628 1266 664 unmeasured (brittle) unmeasured (brittle) 948 660 645 2964 Bursting Strength MPa 165 191 240 243 251 250 170 231 189 157 211 166 237 220 215 247 elongation at break % 8 7 6 7 7 4 6 15 8 4 6 4 4 3 3 12 Tensile modulus GPa 5.2 6.8 7.6 7.6 7.6 7.6 7.6 7.7 6.7 5.3 8.3 6.8 7.8 7.7 7.7 7.7

As shown in Table 1, polyimide films containing 1 mol % of SQ1 in their structure (Examples 1, 2, 3a, 4) were compared to polyimide films containing the same composition except without SQ1 The films (Comparative Examples 1, 2, 6, and 9) showed approximately the same total light transmittance, haze, yellowness index, Tg, and CTE, and it was found that the tensile product increased.

Comparing Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5, in the case of mixing SQ-109 without acid anhydride groups instead of SQ1 with acid anhydride groups at the end, as the addition amount increases to 1%, 15% and 50%, white turbidity of the polyamic acid solution and the polyimide film was observed. Also, when SQ-109 was mixed, no increase in tensile product was observed, and the film became brittle as the added amount increased.

If Examples 3a～3e, Comparative Example 6, Comparative Example 7, and Comparative Example 8 are compared, compared with Comparative Example 6, the tensile products of Examples 3a～3e are improved, but the tensile products of Comparative Example 7 and Comparative Example 8 are The tension product is at the same level as that of Comparative Example 6. Example 3a, Comparative Example 7, and Comparative Example 8 are all polyimides containing silsesquioxane with the same anhydride group (norcamphenic anhydride) in the structure, but the SQ1 used in Example 3a is in The anhydride group and the silsesquioxane structure contain a thioether group, and SQN1 and SQN2 used in Comparative Example 7 and Comparative Example 8 do not contain a thioether group. This suggests that the copolymer of silsesquioxane containing thioether groups in its structure contributes to the increase in tensile strength. (Application example 1) A dispersion obtained by dispersing colloidal silica in NMP ("Snowtex (registered trademark) NMP-ST-ZL" manufactured by Nissan Chemical Industry Co., Ltd.) 0.3% by mass of the total polymer solid content was added to the solution of Example Ca as a slip agent, and stirred at room temperature for 24 hours. Use this as the example Ca2 solution.

Next, the solution of Example Ca2 was applied to the non-slip surface of polyethylene terephthalate film A4100 (manufactured by Toyobo Co., Ltd.) so that the final film thickness became 1.5 μm by a spot coating method, and then The example Ca solution was coated on the example Ca2 solution with a die coater so that the final film thickness would be 22 μm. It was dried at 110° C. for 10 minutes. The self-supporting polyamide film obtained after drying was peeled off from the A4100 film as a support, passed through a pin tenter equipped with a needle plate equipped with pins, and the end of the film was inserted into the pins to carry out Hold to avoid film rupture and avoid unnecessary slack, adjust the needle plate interval and transport, heat at 200°C for 3 minutes, 250°C for 3 minutes, 300°C for 3 minutes, and 400°C for 3 minutes to make it imidization reaction. After that, it was cooled to room temperature for 2 minutes, and the parts with poor planarity at both ends of the film were cut off with a cutter, and rolled into a roll to obtain a polyimide film A1 with a width of 500 m and a width of 450 mm. (Application Example 2) First, the polyimide film obtained in Example 3a (PMDA/TFMB/SQ1) was cut into a rectangle of 360 mm×460 mm. Next, UV/O ₃ was irradiated for 3 minutes using a UV/O ₃ irradiator (SKR1102N-03 manufactured by LAN Technical) as a film surface treatment. At this time, the distance between the UV/O ₃ lamp and the film was set to 30 mm.

3-Aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-903) as a silane coupling agent is coated on a display glass (370mm×470mm, glass substrate with a thickness of 0.7mm: NEC Glass) with a sprayer company-made OA10G). In addition, what was used for the glass substrate was dry-cleaned by irradiating for 1 minute with a UV/O ₃ irradiator (SKR1102N-03 manufactured by LAN Technical) after washing with pure water and drying.

Next, set the glass substrate coated with the silane coupling agent on a roll laminator equipped with a silicone rubber roller, and first use a dropper to drop 500ml of pure water onto the entire substrate to spread the silane coupling agent coating surface to wet the substrate.

The surface-treated surface of the polyimide film that has undergone the above-mentioned surface treatment is overlapped with the silane coupling agent-coated surface of the glass substrate, that is, the surface wetted with pure water. From the beginning, pressurize while extruding pure water between the polyimide film and the glass substrate with rotating rollers sequentially, and laminate the glass substrate and polyimide film to obtain a temporary laminate. The laminator used is a laminator with an effective roll width of 650mm manufactured by MCK Company. The lamination conditions are air source pressure: 0.5MPa, lamination speed: 50mm/s, roll temperature: 22°C, ambient temperature: 22°C, Humidity 55%RH.

The obtained temporary laminate was heat-treated in a clean oven at 200° C. for 10 minutes to obtain a laminate including a polyimide film and a glass substrate.

A tungsten film (film thickness 75nm) was formed on the polyimide film surface of the obtained laminate in the following steps, and a silicon oxide film (film thickness 150nm) was further laminated and formed as an insulating film without exposure to the atmosphere. Next, a silicon oxide nitride film (thickness: 100nm) was formed as a base insulating film by plasma CVD, and an amorphous silicon film (thickness: 54nm) was further laminated without exposure to the atmosphere.

The obtained amorphous silicon film is used to fabricate TFT elements. First, the amorphous silicon film is patterned to form a silicon region of a predetermined shape, and the formation of the gate insulating film, the formation of the gate electrode, the doping of the active region to form the source region or the drain region, and the interlayer insulation are performed appropriately. Formation of film, formation of source electrode and drain electrode and activation treatment, making P-channel TFT array.

About 0.5mm inward along the outer circumference of the TFT array, the polyimide film was burnt with UV-YAG laser, and peeled off from the broken end with a thin razor-like blade to obtain Flexible A3 size TFT array. It can be peeled off with a very small force, and it can be peeled off without damaging the TFT. Even if the obtained flexible TFT array was wound on a 5mmφ round rod, no deterioration in performance was seen, and good characteristics were maintained. [Possibility of industrial use]

As described above, the polyimide film of the present invention exhibits good mechanical properties while maintaining the same level of optical and thermal properties as compared to the case of not containing the silsesquioxane compound. The polyimide film of the present invention has excellent optical properties, colorless transparency and excellent mechanical properties, and exhibits a lower CTE, so after the film is bonded to a flat inorganic substrate such as glass and has rigidity, the film Various electronic components are processed on it, and finally it is peeled off from the inorganic substrate, so that flexible electronic components can be produced.

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Fig. 1 is a graph showing ^{the 1} HNMR (CDCl ₃ ) spectrum of SQ109 (PGMEA solution) used in Synthesis Example 2-1. Figure 2 is a graph showing ^{the 1} HNMR (CDCl ₃ ) spectrum of PGMEA. In addition, δ=2.2 is the peak from the acetone used to clean the utensils. Fig. 3 is a graph showing ^{the 1} HNMR (CDCl ₃ ) spectrum of norbornene anhydride used in Synthesis Example 2-1. In addition, δ=2.2 is the peak from the acetone used to clean the utensils. Fig. 4 is a graph showing ^{the 1} HNMR (CDCl ₃ ) spectrum of the reaction mixture after the reaction in Synthesis Example 2-1. Fig. 5 is a graph showing ^{the 1} HNMR (CDCl ₃ ) spectrum of silsesquioxane SQ2 having an acid anhydride group obtained in Synthesis Example 2-2. Fig. 6 is a graph showing the ¹ H NMR (DMSO-d ₆ ) spectrum of silsesquioxane SQ3 having an acid anhydride group obtained in Synthesis Example 2-3. Fig. 7 is a graph showing the ¹ H NMR (DMSO-d ₆ ) spectrum of silsesquioxane SQ4 having an acid anhydride group obtained in Synthesis Example 2-4. Fig. 8 is a graph showing the ¹ H NMR (DMSO-d ₆ ) spectrum of silsesquioxane SQ5 having an acid anhydride group obtained in Synthesis Example 2-5. Fig. 9 is a graph showing the ¹ H NMR (DMSO-d ₆ ) spectrum of silsesquioxane SQ6 having an acid anhydride group obtained in Synthesis Example 2-6. Fig. 10 is a graph showing ^{the 1} H NMR (DMSO-d ₆ ) spectrum of silsesquioxane SQ7 having an acid anhydride group obtained in Synthesis Example 2-7. Fig. 11 is a graph showing ^{the 1} H NMR (DMSO-d ₆ ) spectrum of silsesquioxane SQ8 having an acid anhydride group obtained in Synthesis Example 2-8.

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Claims (15)

A kind of polyamic acid, it is the copolymerization reactant of at least carboxylic acid, diamines and the silsesquioxane compound A that has dicarboxylic acid anhydride group, wherein, this silsesquioxane compound A is by following a1 The silsesquioxane compound A formed by reacting the thiol group of the condensate B of a2 with the reactive group of the dicarboxylic anhydride C; general formula: the third thiol group represented by R ¹ Si(OR ² ) ₃ Alkoxysilanes a1 (wherein, R ¹ represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or at least one hydrogen of an aromatic hydrocarbon group with 6 to 8 carbons is replaced by An organic group of a thiol group, ^R2 independently represent a hydrogen atom, an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons or an aromatic hydrocarbon group with 6 to 8 carbons); Thiol-based trialkoxysilanes a2; The reactive group of the dicarboxylic acid anhydride C is at least one reactive group selected from vinyl, alkenyl, cycloalkenyl, alkynyl and acyl chloride. A polyamic acid, which is a copolymerization reaction product of at least carboxylic acids, diamines and a silsesquioxane compound A having a dicarboxylic anhydride group, wherein the silsesquioxane compound A has the following general formula Structural units represented by (1) and (2):

(wherein, Q ¹ represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons, Q ² is a single bond, an aliphatic hydrocarbon with 1 to 8 carbons Hydrocarbon group, organic group or carbonyl group in which one or more carbon atoms in the hydrocarbon group with 1 to 8 carbon atoms is replaced by oxygen, X is a carbon-carbon bond or an aliphatic ring with 4 to 10 carbon atoms, and an organic group with 6 to 10 carbon atoms Aromatic rings, or heterocyclic rings in which part of the carbon constituting them is replaced by oxygen or sulfur; one or more of the hydrogens bonded to these rings may also be replaced by hydrocarbon groups; 1.0≤m≤2.0; 1.4≤n≤ 1.6);

(wherein, ^Q represents an aliphatic hydrocarbon group with 1 to 8 carbons, an alicyclic hydrocarbon group with 4 to 8 carbons, or an aromatic hydrocarbon group with 6 to 8 carbons; 1.4≤n≤1.6). The polyamic acid as claimed in claim 1 or 2, wherein the molar ratio of the trialkoxysilanes a2 in the silsesquioxane compound A ([the molar number of a2]/[the molar number of a1 + the molar number of a2]) or the molar ratio of the structural unit represented by the general formula (2) ([structural unit (2)]/[structural unit (1)+structural unit (2)]) is 0.1 to 0.7 . The polyamic acid as claimed in item 1 or 3, wherein the dicarboxylic anhydride C is a compound selected from the following chemical formulas:

(In the formula, Rx represents an aliphatic hydrocarbon group having 1 to 8 carbons, an alicyclic hydrocarbon group having 4 to 8 carbons, or an aromatic hydrocarbon group having 6 to 8 carbons). The polyamic acid according to any one of claims 1 to 4, wherein the molar content of the divalent monomer derived from the structural unit of the silsesquioxane compound A as a benchmark: (nA/(nA+ nD))×100 (herein, nA is the value obtained by dividing the total number of moles of structural units derived from the silsesquioxane compound A by the total number of the dicarboxylic anhydride groups and multiplying by 2 times; nD is the number of moles of structural units derived from the carboxylic acids) is 0.01 to 10.0 mole%. The polyamic acid according to any one of claims 1 to 5, wherein the carboxylic acids are selected from more than one compound represented by the following chemical formula:

. The polyamic acid according to any one of claims 1 to 6, wherein the diamines comprise 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB) or 4 ,4'-Diaminobenzamidobenzene (DABA). A polyamic acid composition comprising the polyamic acid according to any one of claims 1 to 7 and a solvent. A polyimide, which is formed by imidization of the polyamic acid according to any one of claims 1 to 7. A polyimide film comprising the polyimide according to claim 9. For example, the polyimide film according to Claim 10 has a coefficient of linear expansion of 40 ppm/K or less and -20 ppm/K or more. The polyimide film according to claim 10 or 11, wherein the tensile product in the tensile test is not less than 1,000 MPa·% and not more than 10,000 MPa·%. A laminate comprising the polyimide film and the inorganic substrate according to any one of claims 10 to 12. A method of manufacturing a flexible electronic component, comprising: The step of forming electronic components on the polyimide film surface of the laminate as claimed in claim 13; and A step of peeling off the inorganic substrate. A flexible electronic component comprising the polyimide film according to any one of claims 10 to 12 and an electronic component formed on the polyimide film.

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