JP2008163089A - Copolymer containing at least alicyclic polyesterimide unit and aromatic polyimide unit, and polyimide film - Google Patents

Abstract

（式（１）中、Ａは２価の基を示す。Ｘは２価の芳香族基を示す。Ｙは芳香族基を示す。ｓおよびｔは、各々独立に０、１、又は２を表す。）
【選択図】図１A novel copolymer composed of an alicyclic polyesterimide and an aromatic polyimide, which has good heat resistance and high solubility in an organic solvent.
A copolymer of an alicyclic polyesterimide represented by the general formula (1) and an aromatic polyimide. A polyimide film formed by molding a copolymer of this alicyclic polyesterimide and an aromatic polyimide.

(In formula (1), A represents a divalent group, X represents a divalent aromatic group, Y represents an aromatic group, and s and t each independently represent 0, 1, or 2. To express.)
[Selection] Figure 1

Description

The present invention relates to a copolymer containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit, and in particular, heat resistance and solubility in organic solvents can be arbitrarily adjusted. The present invention relates to a copolymer containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit whose properties can be controlled. The present invention also relates to a polyimide film formed by molding a copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit.
The alicyclic polyesterimide unit referred to here is the minimum structural unit of polyimide obtained from alicyclic tetracarboxylic dianhydride and diamine, and the aromatic polyimide unit is aromatic tetracarboxylic dianhydride. The minimum constitutional unit of polyimide obtained from the product and diamine shall be indicated respectively.

  Polyimide has not only excellent heat resistance but also chemical resistance, radiation resistance, electrical insulation, excellent mechanical properties, etc., so it can be used for flexible printed circuit boards, tape automation bonding substrates, and semiconductors. Currently, it is widely used in various electronic devices such as protective films for elements and interlayer insulating films for integrated circuits. Polyimide is also a very useful material in terms of simplicity of production method, high film purity, and ease of improving physical properties, and functional polyimide material designs suitable for various applications have been made in recent years.

  Since many polyimides are insoluble in organic solvents and do not melt even above the glass transition temperature, it is usually not easy to mold the polyimide itself. For this reason, polyimide is generally obtained by first reacting an aromatic tetracarboxylic dianhydride such as pyromellitic anhydride with an aromatic diamine such as diaminodiphenyl ether in an aprotic polar organic solvent such as dimethylacetamide to obtain a high molecular weight. A polyimide precursor having a polymerization degree is polymerized, this solution is formed into a film or the like, heated at a temperature of about 250 ° C. to 350 ° C., and dehydrated and closed (imidized) to form a film.

  Thermal stress generated in the process of cooling the polyimide / metal substrate laminate from the imidization temperature to room temperature often causes serious problems such as curling, film peeling and cracking. Recently, with the increase in the density of electronic circuits, multilayer wiring boards have come to be used. However, even if film peeling or cracking does not occur, the residual stress in the multilayer board can increase device reliability. Reduce significantly. For this reason, reduction of thermal stress has also been studied, but these low thermal stress resins have a problem of low solubility in solvents and poor operability.

  On the other hand, when polyimide is soluble in an organic solvent, a thermal imidization step is not required. Therefore, after applying a polyimide organic solvent solution (varnish) on a metal substrate, the solvent is removed at a temperature much lower than the thermal imidization temperature. It is only necessary to evaporate and dry, and it is possible to reduce the thermal stress in the metal substrate / insulating film laminate. However, there are only a limited number of polyimides that are soluble in organic solvents and put into practical use, and development of polyimides having various physical properties that are soluble in solvents is awaited.

  The present invention solves the above-mentioned problems of conventional aromatic polyimides, and is a novel copolymer composed of alicyclic polyesterimide units and aromatic polyimide units, which has good heat resistance and high solubility in organic solvents. The purpose is to provide.

  As a result of intensive studies to solve the above problems, the present inventors have made a copolymer containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit, whereby the heat resistance of the aromatic polyimide component and the alicyclic structure are obtained. A polyimide resin having both the solubility of the polyesterimide component in the organic solvent is obtained, and furthermore, by adjusting the ratio of the alicyclic polyesterimide component and the aromatic polyimide component, heat resistance and resistance to the organic solvent are obtained. It was found that the solubility can be controlled and an imide resin having desired characteristics can be obtained.

  The present invention has been achieved based on the above findings, and the gist thereof is as follows.

（式（１）中、Ａは２価の基を示す。Ｘは２価の芳香族基を示す。Ｙは芳香族基を示す。ｓおよびｔは、各々独立に０、１、又は２を表す。） [1] A copolymer containing at least an alicyclic polyesterimide unit represented by the general formula (1) and an aromatic polyimide unit.

(In formula (1), A represents a divalent group, X represents a divalent aromatic group, Y represents an aromatic group, and s and t each independently represent 0, 1, or 2. To express.)

[2] The alicyclic polyesterimide unit and aromatic polyimide unit according to [1], wherein the molar ratio of m: n represented by the general formula (1) is 1:20 to 20: 1 And a copolymer.

[3] A polyimide film formed by molding a copolymer containing the alicyclic polyesterimide unit and the aromatic polyimide unit described in [1] or [2].

Since the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is a copolymer of an alicyclic polyesterimide component and an aromatic polyimide component, An imide resin having both solubility in an organic solvent and heat resistance of the aromatic polyimide component can be obtained.
In addition, the ratio of the alicyclic polyesterimide component is increased to lower the glass transition point to increase the solubility in organic solvents to improve the molding processability, or the ratio of the alicyclic polyesterimide component is reduced to aromaticity. It is also possible to increase the ratio of the polyimide component to make it highly heat resistant, and the physical properties of the resulting imide resin can be arbitrarily adjusted by the component ratio of the copolymerization component.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. However, the description of constituent elements described below is an example (representative example) of an embodiment of the present invention, and is not specified by these contents.

  The copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is represented by the following general formula (1). Preferably, it is a copolymer composed of an alicyclic polyesterimide unit and an aromatic polyimide unit.

（式（１）中、Ａは２価の基を示す。Ｘは２価の芳香族基を示す。Ｙは芳香族基を示す。ｓおよびｔは、各々独立に０、１、又は２を表す。）

(In formula (1), A represents a divalent group, X represents a divalent aromatic group, Y represents an aromatic group, and s and t each independently represent 0, 1, or 2. To express.)

  In the general formula (1), the structure of A contained in the alicyclic polyesterimide component is not particularly limited as long as it is bonded to a carboxy group so as to form the above structure at two locations.

Among these divalent groups, a group having a cyclic structure is preferable. The structure having a cyclic structure means a structure containing an aromatic group in A or a structure containing an alicyclic structure. When A has a cyclic structure, improvement in mechanical properties and improvement in dimensional stability are achieved when an imide resin is used. Moreover, when the alicyclic structure is included, it is possible to obtain a feature that light absorption in the UV region can be reduced while maintaining moderate heat resistance. Specific examples of the structure include phenylene group, naphthylene group, biphenylene group, diphenyl ether group, diphenylsulfone group, 4,4 ′-(9-fluorenylidene) diphenyl, which are all divalent groups as aromatic groups. Group, methylenediphenyl group, isopropylidenediphenyl group, 3,3 ′, 5,5′-tetramethyl- (1,1′-biphenyl) group and the like, and alicyclic structures include cyclohexylene group, cyclohexanediphenyl group, and the like. A methylene group, a decahydronaphthylene group, etc. are mentioned. Furthermore, a structure in which a plurality of these groups are bonded to each other or a linking group may be used. Specific examples of the linking group applicable here include a methylene group (—CH ₂ —), an ether group (—O—), an ester group (—C (O) O—), a keto group (—C ( O)-), a sulfonyl group (—SO ₂ —), a sulfinyl group (—SO—), a sulfenyl group (—S—), a 9,9-fluorenylidene group, and the like. In addition, regarding the group containing the above-mentioned divalent cyclic structure, the substitution position is not particularly limited. For example, a phenylene group is preferably substituted at the 1,4-position, since the structure of -A- becomes a straight line, thus improving the dimensional stability and reducing the linear expansion coefficient. On the other hand, substitution at the 1,3-position in the phenylene group is preferable because the -A- structure is bent, so that improvement in solubility in a solvent is expected. Therefore, as for the substitution position, it is preferable to select A having an appropriate structure according to the required physical properties.

  In a more preferred structure, A is a group containing an aromatic group. When an aromatic group is contained, the mechanical properties and dimensional stability of the imide resin are further improved, and the refractive index is improved. Specific examples of the aromatic group include those described above. Among them, phenylene group, biphenylene group, diphenyl ether group, diphenyl sulfone group, 4,4 ′-(9-fluorenylidene) diphenyl group, 3, The 3 ′, 5,5′-tetramethyl- (1,1′-biphenyl) group or the like is particularly preferable in that it has a more rigid structure. Furthermore, phenylene group, 4,4 ′-(9-fluorenylidene) diphenyl group, 3,3 ′, 5,5′-tetramethyl- (1,1′-biphenyl) group is a raw material, and the resulting resin This is preferable because of its good physical properties.

s and t each independently represent 0, 1 or 2, preferably 0 or 1, and more preferably 0.
Specific examples of the structure of the alicyclic tetracarboxylic dianhydride include those represented by the following formula group (Z). Of course, as described above, a combination of -A- and n is free. It is possible to design the structure.

<(Z) group>

  On the other hand, in the general formula (1), Y contained in the aromatic polyimide unit is a tetravalent aromatic group, and the aromatic tetracarboxylic dianhydride used when the copolymer of the present invention is produced. The aromatic tetracarboxylic dianhydride containing Y includes the following. These may be used alone or in combination of two or more.

  Acid dianhydride composed of one aromatic group such as pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3′-benzophenone tetracarboxylic acid Anhydride, 2,3 ′, 3,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3 ′, 3,4′-biphenyl Tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) ) Sulfone dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane Consists of two aromatic acid anhydride structures such as anhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride Acid dianhydrides such as 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride and the like An anhydride etc. are mentioned.

  Preferable as aromatic tetracarboxylic dianhydride containing Y is pyromellitic dianhydride, 3, 3 ′, in terms of easy availability among them, and further in terms of excellent physical properties of the resulting polyimide. -Benzophenone tetracarboxylic dianhydride, 2,3 ', 3,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (3,4 -Dicarboxyphenyl) ether dianhydride, and the like.

  X is a divalent aromatic group, which is derived from a diamine used in producing the copolymer of the present invention. Examples of the diamine include the following.

  As aromatic diamines, 3,5-diaminobenzotrifluoride, 2,5-diaminobenzotrifluoride, 3,3′-bistrifluoromethyl-4,4′-diaminobiphenyl, 3,3′-bistrifluoromethyl- 5,5′-diaminobiphenyl, bis (trifluoromethyl) -4,4′-diaminodiphenyl, bis (fluorinated alkyl) -4,4′-diaminodiphenyl, dichloro-4,4′-diaminodiphenyl, dibromo- 4,4′-diaminodiphenyl, bis (fluorinated alkoxy) -4,4′-diaminodiphenyl, diphenyl-, 4′-diaminodiphenyl, 4,4′bis (4-aminotetrafluorophenoxy) tetrafluorobenzene, 4,4′-bis (4-aminotetrafluorophenoxy) octafluorobiphe 4,4'-binaphthylamine, o-, m-, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, Dimethyl-4,4′-diaminodiphenyl, dialkyl-4,4′-diaminodiphenyl, dimethoxy-4,4′-diaminodiphenyl, diethoxy-4,4′-diaminodiphenyl, 4,4′-diaminodiphenylmethane, 4, 4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-a Nophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, bis (4 (3-aminophenoxy) phenyl) sulfone, bis (4- ( 4-aminophenoxy) phenyl) sulfone, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2, 2-bis (4- (3-aminophenoxy) phenyl) propane, 2,2-bis (4- (3-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (4-amino) -2-trifluoromethylphenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (3-amino-5-trifluoromethylphenol) Noxy) phenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (3-amino-) 4-hydroxyphenyl) hexafluoropropane, 2,2 bis (3-amino-4-methylphenyl) hexafluoropropane, 4,4′-bis (4-aminophenoxy) octafluorobiphenyl, 4,4′- Diaminobenzanilide etc. can be illustrated and these can also be used together 2 or more types.

  Examples of the aliphatic diamine include 4,4′-methylenebis (cyclohexylamine), isophoronediamine, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-cyclohexanebis (methylamine), 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 3,8-bis (aminomethyl) tricyclo [5 .2.1.0] decane, 1,3-diaminoadamantane, 2,2-bis (4-aminocyclohexyl) propane, 2,2-bis (4-aminocyclohexyl) hexafluoropropane, 1,3-propanediamine 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenedia Emissions, 1,7 heptamethylene diamine, 1,8-octamethylene diamine, 1,9-nonamethylenediamine, and the like. Two or more of these may be used in combination.

Furthermore, siloxane group-containing diamines such as 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane can also be used.
Among these diamines, aromatic diamines include mononuclear phenylenediamine compounds such as o-, m-, and p-phenylenediamine, 4,4'-diaminodiphenyl, 4,4'-diaminodiphenylsulfone, 4,4. Diaminodiphenyl compounds such as' -diaminodiphenylmethane and 4,4'-diaminodiphenyl ether are preferable. Among them, p-phenylenediamine, 4,4'-diaminodiphenyl ether, More preferred is 4,4′-diaminodiphenyl. As the aliphatic diamine, alicyclic diamines such as 4,4′-methylenebis (cyclohexylamine), trans-1,4-diaminocyclohexane, isophoronediamine and the like are preferable because they have a ring structure and are easily available. The resin from which trans-1,4-diaminocyclohexane is obtained is more preferable because of good physical properties.

  In the general formula (1), the m: n molar ratio indicating the ratio of the alicyclic polyesterimide unit to the aromatic polyimide unit is not particularly limited, and is set within a wide range of, for example, 1:20 to 20: 1. be able to. In particular, when the obtained copolymer has a low glass transition point, is excellent in an organic solvent, and is excellent in molding processability, the alicyclic polyesterimide moiety is large, and the molar ratio of n: m is The ratio is preferably 1:15 to 15: 1, particularly 10: 1 to 1:10. When the glass transition point is high and heat resistance is required to be maintained, the aromatic polyimide portion is increased. The n: m molar ratio is preferably in the range of 10:10 to 1:19, particularly 4: 6 to 1: 9.

  The copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention corresponds to the alicyclic tetracarboxylic dianhydride corresponding to the alicyclic polyesterimide component and the aromatic polyimide component. It can be obtained by reacting an aromatic tetracarboxylic dianhydride with the above-mentioned diamine to obtain a copolymer precursor (also referred to as copolymerized amic acid) and then imidizing. The method of adding the reagent at this time has an influence on the chain structure of the resulting polyimide, and therefore needs to be selected according to the desired physical properties. For example, a method in which an alicyclic tetracarboxylic dianhydride and an aromatic tetracarboxylic dianhydride are mixed in advance in a reactor and a diamine is added thereto, and the alicyclic tetracarboxylic dianhydride is reacted. A method of adding an aromatic tetracarboxylic dianhydride after adding the same amount of diamine as the alicyclic tetracarboxylic dianhydride and adding an aromatic tetracarboxylic dianhydride to the vessel, And a method in which the addition order of the alicyclic tetracarboxylic dianhydride and the aromatic tetracarboxylic dianhydride is reversed by this method, or a diamine is first charged in the reactor and the alicyclic tetracarboxylic carboxylic acid is added thereto. A method of adding a mixture of an acid dianhydride and an aromatic tetracarboxylic dianhydride, and an alicyclic tetracarboxylic dianhydride and an aromatic tetracarboxylic dianhydride sequentially in this order A method of adding and method of adding in reverse order, and the like. Of course, addition methods other than those exemplified here can be employed as necessary.

  As the alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride and diamine described here, one kind of compound classified into each component may be used alone, or two or more kinds may be used. May be used in combination. There is no particular limitation on the method of adding the reagent when used in combination, and the method of adding the reagent can be freely selected.

  The ratio of the total of alicyclic tetracarboxylic dianhydride and aromatic tetracarboxylic dianhydride to diamine is preferably 1: 0.8 to 1.2 in molar ratio. As in the normal polycondensation reaction, the closer the molar ratio is to 1: 1, the higher the molecular weight of the polyamic acid obtained. Here, the m: n ratio in the general formula (1) can be controlled by appropriately adjusting the use ratio of the alicyclic tetracarboxylic dianhydride and the aromatic tetracarboxylic dianhydride.

If the reaction temperature is too low, the solubility of the reagent is lowered, a sufficient reaction rate cannot be obtained, and if it is too high, it is difficult to control the progress of the reaction. Usually, the lower limit is −20 ° C., preferably −10 ° C., more preferably 0 ° C., and the upper limit is 150 ° C., preferably 100 ° C., more preferably 60 ° C.
Although the reaction time can be adopted without any particular limitation, in order to achieve a sufficient reagent conversion rate, the lower limit is 10 minutes, preferably 30 minutes, more preferably 1 hour, and the upper limit is not particularly limited, but the reaction is completed. There is no need to extend the reaction time more than necessary. For example, 100 hours, preferably 50
Time, more preferably 30 hours, is employed.

  The polymerization reaction is performed using a solvent. The solvent used in this case is not particularly limited as long as it is a solvent in which diamine and tetracarboxylic dianhydride as raw material monomers do not react with the solvent and these raw materials dissolve, and the structure is not particularly limited. Specifically, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε -Cyclic ester solvents such as caprolactone, α-methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, lactam solvents such as caprolactam, ether solvents such as dioxane, glycol solvents such as triethylene glycol, m- Phenolic solvents such as cresol, p-cresol, 3-chlorophenol, 4-chlorophenol, 4-methoxyphenol, 2,6-dimethylphenol, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane , Dimethyl Sulfoxide, tetramethyl urea are preferably employed. In addition, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate , Tetrahydrofuran, dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methyl ethyl ketone, acetone, butanol, ethanol, xylene, toluene, chlorobenzene, terpene, mineral spirit, petroleum naphtha A solvent etc. can also be added and used. Of these, aprotic solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, and γ-butyrolactone are preferred because of the high solubility of the raw materials.

  The solvent is preferably used in such an amount that the weight concentration of the total amount of tetracarboxylic dianhydrides and diamines as raw materials falls within the following range. That is, the concentration is 0.1% by weight or more, preferably 1% by weight or more, more preferably 5% by weight or more, although the upper limit is not particularly limited, but from the viewpoint of solubility of tetracarboxylic dianhydrides, 80% by weight. % Or less, preferably 50% by weight or less, more preferably 30% by weight or less. By carrying out polymerization in the concentration range of the tetracarboxylic dianhydrides, a uniform and high degree of polymerization of the polyimide precursor solution can be obtained. In order to impart film toughness to the target polyesterimide, the degree of polymerization of the polyesterimide precursor is preferably as high as possible. When polymerization is performed at a concentration lower than the above concentration range, the degree of polymerization of the polyimide precursor is sufficient. Is not preferable, and the finally obtained polyimide film may be brittle. When an alicyclic diamine is used as the diamine, a higher polymerization concentration requires a longer polymerization time until the formed salt dissolves and disappears, which may lead to a decrease in productivity.

If necessary, inorganic salts may be used as a catalyst in the production of the precursor. Examples of inorganic salts used at this time include alkali metal halides such as LiCl, NaCl, and LiBr, alkaline earth metal halides such as CaCl2, and metal halides such as ZnCl2. Of these, metal chlorides such as LiCl, CaCl 2 and ZnCl 2 are particularly preferred.
The reaction is preferably carried out with stirring during the process.

  The intrinsic viscosity of the precursor containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit thus obtained is not particularly limited, but the preferred intrinsic viscosity has a lower limit of 0.3 dL / g, preferably 0.5 dL / g, more preferably 0.7 dL / g. On the other hand, the upper limit is 5.0 dL / g, preferably 3.0 dL / g, more preferably 2.0 dL / g.

  A copolymer containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit is synthesized from a copolymer precursor containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit. And chemical imidization methods. However, the production method of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is not particularly limited to the production method described below.

The copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is a copolymer precursor containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit obtained by the above method. Can be produced by cyclizing imidization reaction.
At this time, the form which can produce the copolymer containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit is a film, a powder, a molded product and a solution.

  A copolymer film containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit can be produced, for example, as follows. First, a polymerization solution (varnish) of a copolymer precursor containing at least the alicyclic polyesterimide unit and an aromatic polyimide unit is placed on a substrate such as glass, copper, aluminum, silicon, quartz plate, stainless steel plate, or Kapton film. Cast and apply. As a coating method, a copolymer precursor solution containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit obtained as described above is dropped onto the above-mentioned substrate and the height is fixed. It can be applied to a uniform height by stretching the solution on the body. At this time, it may be performed using a device such as a doctor blade. As other coating methods, any method capable of coating the solution with a predetermined thickness, such as a spin coating method, a printing method, and an ink jet method, can be employed without any limitation.

  Since the coating film thus applied contains a solvent, it is then dried. The lower limit of the drying temperature employed at that time is usually 20 ° C., preferably 40 ° C., more preferably 60 ° C. On the other hand, the upper limit is 200 ° C, preferably 150 ° C, more preferably 100 ° C.

The drying time can be used without particular limitation as long as the solvent is removed to some extent, but the lower limit is 10 minutes, preferably 30 minutes, more preferably 1 hour, and the upper limit is not particularly limited, but 50 hours, preferably 30 Time, more preferably 10 hours, is employed.
Drying may be performed under reduced pressure. The degree of reduced pressure employed at that time is usually 0.05 MPa or less, preferably 0.01 MPa or less, more preferably 0.001 MPa or less.

  The thus obtained dried copolymer precursor film containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit is heated on a substrate in a vacuum, in an inert gas such as nitrogen, or in air at a high temperature. Turn into. This method is called heat imidization.

  The lower limit of the temperature employed at this time is 180 ° C., preferably 200 ° C., more preferably 250 ° C. On the other hand, the upper limit is 500 ° C., preferably 400 ° C., more preferably 350 ° C. When the heating temperature is 180 ° C. or lower, the cyclization reaction of the cyclization imidation reaction is not preferable because it is incomplete, and when it is too high, it includes at least the produced alicyclic polyesterimide unit and aromatic polyimide unit. Since the copolymer film may be pyrolyzed and colored, it is not preferable. The imidization is preferably performed in a vacuum or in an inert gas, but may be performed in air if the temperature of the imidization reaction is not too high. The degree of reduced pressure employed when the heat imidization is performed under reduced pressure is usually 0.05 MPa or less, preferably 0.01 MPa or less, and more preferably 0.001 MPa or less.

  The time for which the cyclization imidation proceeds sufficiently is adopted as the heating time, but usually the lower limit is 5 minutes, preferably 10 minutes, more preferably 20 minutes, and the upper limit is not particularly limited, but 20 hours, preferably 10 hours, more preferably 5 hours are employed.

  The thickness of the copolymer film containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention thus obtained can be freely controlled by changing the thickness of the solution to be applied. The lower limit of the specific film thickness is usually 0.1 μm, preferably 1 μm, more preferably 5 μm, and the upper limit is usually 1000 μm, preferably 700 μm, more preferably 500 μm.

  When the precursor of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is chemically imidized, the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is used. The polymer can be obtained as a solution, and further, a copolymer powder can be obtained by treatment with a solvent in which the copolymer does not dissolve. This powder can be converted into various forms.

  As a method that can be adopted in chemical imidization, any method can be adopted as long as it is a generally used method. For example, the precursor is treated with a dehydrating reagent and a basic substance.

  Examples of what can be used as a dehydrating reagent include acid anhydrides of lower carboxylic acids such as acetic anhydride and trifluoroacetic anhydride, aromatic dicarboxylic acid anhydrides such as trimellitic anhydride and pyromellitic anhydride, N , N-dicyclohexylcarbodiimide and other alkyl carbodiimides. The lower limit of the amount used is usually 1.0 mol times, preferably 2.0 mol times, more preferably 4.0 mol times, with respect to the number of moles of amic acid groups contained in the precursor. Although there is no restriction | limiting, Usually, it is 50 mol times, Preferably it is 30 mol times, More preferably, it is 20 mol times. If the amount of the dehydrating reagent is too small, the progress of the reaction is delayed, and if the amount is too large, there is a problem that it remains in the target product.

  On the other hand, examples of basic substances that can be used include, but are not limited to, organic tertiary amines such as pyridine, triethylamine, tributylamine, N, N-dimethylaniline, dimethylaminopyridine, potassium carbonate, sodium hydroxide, and the like. An inorganic basic substance can be used. Of these, pyridine and triethylamine are preferable in that they can be obtained at low cost and can be easily operated because they are liquid and rich in solubility.

  The reaction solution of the chemical imidization product thus obtained can be obtained as a copolymer powder by treating with a solvent in which the copolymer does not dissolve. Solvents that do not dissolve the copolymer that can be used at this time are not particularly limited, and examples include water, methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. it can. The specific polymer that has been deposited in a poor solvent and collected by filtration can be recovered by filtration, and then dried at room temperature or under reduced pressure at normal temperature or under reduced pressure.

  Moreover, when the powdered polymer is redissolved in an organic solvent and reprecipitation and recovery are repeated 2 to 10 times, impurities in the polymer can be reduced. In this case, it is preferable to use three or more kinds of poor solvents such as alcohols, ketones, and hydrocarbons as the poor solvent because the purification efficiency is further increased.

  The powder copolymer thus obtained can be made into a solution (varnish) by dissolving it again in a solvent.

  As the solvent that can be used in this case, the solvent used in the synthesis of the copolymer precursor containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention can be used.

  In addition to this, for the purpose of improving coating film uniformity, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2- Acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamid The solvent having a low surface tension, such as esters may also be used. These solvents may be used alone or in combination.

  The imide solution (varnish) of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit thus obtained can be used as a coating material for various materials for film formation and coating. Can be made into a film. The thickness of the film thus obtained is the same as that described above for the film produced by thermal imidization.

  The copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention exhibits high solvent solubility. Examples of the solvent that can dissolve the copolymer include N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, and γ-butyrolactone.

  The glass transition point Tg (° C.) of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is usually 130 ° C., preferably 140 ° C., more preferably 150 ° C., The upper limit is usually in the range of 250 ° C., preferably 240 ° C., more preferably 230 ° C., and the moldability is excellent.

5% weight loss temperature as another index representing heat resistance is usually 250 ° C. or higher, preferably 300 ° C. or higher, more preferably 350 ° C. or higher in an inert gas atmosphere, and usually 220 ° C. or higher, preferably in an air atmosphere. It is 300 ° C. or higher, more preferably 350 ° C. or higher.
The pencil hardness (JIS-K5400) of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is usually in the range of B to 7H, preferably in the range of H to 4H. is there.

  The upper limit of the refractive index of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is usually 1.75, preferably 1.70, more preferably 0.68, and the lower limit is 1. 50, preferably 1.53, more preferably 1.55. It is well known that the introduction of fluorine atoms into the resin lowers the refractive index. However, when fluorine atoms are introduced into the polymer of the present invention, the refractive index decreases. Is 1.65, preferably 1.63, more preferably 1.60, and the lower limit is usually 1.45, preferably 1.48, more preferably 1.50.

  The dielectric constant at 1 MHz of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is usually 4.0 or less, preferably 3.5 or less, more preferably 3.3 or less. is there. In addition, it is well known that when a fluorine atom is introduced into the resin, the dielectric constant is lowered. However, when a fluorine atom is introduced into the polymer of the present invention, the dielectric constant is lowered. .5 or less, preferably. 3.3 or less, more preferably 3.0 or less. Further, the frequency tangent of the dielectric loss tangent is also low in the range of 1 to 20 GHz, and it has a characteristic of showing a substantially constant value in the range of 0.005 to 0.020, and has extremely excellent high frequency characteristics.

  The amount of foreign particles contained in the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is usually the above-mentioned insoluble fine particles having a projected area equivalent circle diameter of 5 to 20 μm. As described above, the number is 5000 or less, preferably 3000 or less, and more preferably 1000 or less per 1 g of the polymer.

  The water absorption when the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is immersed in water at 25 ° C. for 24 hours is usually 10% by weight or less, preferably 5% by weight or less, More preferably, it is 3% by weight or less.

  The linear thermal expansion coefficient of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is usually 100 ppm / K or less, preferably 50 ppm / K or less, more preferably 30 ppm / K.

  The copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention exhibits high solubility in a solvent. In particular, it dissolves well in the solvent used when synthesizing the polyimide precursor described above and can be easily made into a solution.

  The copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention can be bent flexibly when used as the above-described film, and returns to a flat film when restored. Has a characteristic. Usually, the film of the copolymer of the alicyclic polyesterimide and the aromatic polyimide of the present invention can be produced as an excellent film that does not break even if it is bent by 180 °.

  The tensile strength when the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is used as a film is usually 10 MPa or more, preferably 30 MPa or more, more preferably 50 MPa or more.

  The tensile elastic modulus when the film comprising a copolymer containing at least an alicyclic polyesterimide unit and an aromatic polyimide unit of the present invention is usually 0.1 GPa or more, preferably 0.5 GPa or more, more preferably 1. 0 GPa or more.

  The tensile elongation of the film of the copolymer containing at least the alicyclic polyesterimide unit and the aromatic polyimide unit of the present invention is usually 0.1%, preferably 0.5%, more preferably 1 0.0%, and the upper limit is usually 100% or less, preferably 50% or less, and more preferably 30% or less.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples, unless the summary is exceeded.
In the following, the intrinsic viscosity of the polyesterimide precursor, the glass transition point of the polyesterimide, and the NMR spectrum are measured as follows.

<Intrinsic viscosity>
The 0.5 wt% polyesterimide precursor solution was measured at 30 ° C. using an Ubbelohde viscometer.

<Glass dislocation point>
Using a differential scanning calorimeter (DSC 6220) manufactured by SII NanoTechnology, the heating rate was 10 ° C./min. DSC measurement was performed under the conditions described above to determine the glass transition temperature.

<Proton NMR spectrum>
The product was dissolved in deuterated dimethyl sulfoxide and measured using a proton ( ¹ H) resonance frequency 400 MHz NMR spectrometer.

Moreover, the symbol of each compound used for manufacture of a polyesterimide is as follows.
BPDA; 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PMDA; pyromellitic anhydride DMAc; N, N-dimethylacetamide ODA; 4,4′-diaminodiphenyl ether PDA; p-phenylenediamine

[Synthesis Example 1] Synthesis of hydroquinone hydrogenated trimellitic acid diester In a 500 mL four-necked flask under nitrogen flow, 13.81 g (125 mmol) of hydroquinone and 20.24 g (256 mmol) of pyridine were dissolved in 160 ml of tetrahydrofuran, and the ice bath was used. At 0 ° C. A solution obtained by dissolving 55.43 g (256 mmol) of nuclear hydrogenated trimellitic anhydride chloride in 110 mL of tetrahydrofuran was added dropwise thereto. After completion of the dropwise addition, the mixture was returned to room temperature and reacted for 15 hours. After the reaction, the precipitated white solid was separated by filtration and washed 4 times with 40 ml of water to remove the hydrochloride. This was vacuum dried at 120 ° C. to obtain 47.8 g (yield: 81.0%) of a hydroquinone hydrogenated trimellitic acid diester.

  To the 1 L three-necked flask, 23.9 g of the above crude product, 200 ml of acetic anhydride and 300 ml of acetic acid were added and dissolved at 140 ° C. This was cooled at room temperature, and the precipitated solid was separated by filtration and then vacuum dried at 150 ° C. to obtain 13.7 g of purified hydroquinone hydrogenated trimellitic acid diester having the following structure.

[Example 1] Production of polyimide copolymer of hydroquinone hydrogenated trimellitic acid diester / BPDA / ODA (feeding ratio 9: 1: 10) In a 50 mL three-necked flask, 0.499 g (2.49 mmol) of ODA and DMAc3. 90 g was added and stirred at room temperature to dissolve. This was cooled in an ice bath, 1.06 g (2.26 mmol) of the purified hydroquinone hydrogenated trimellitic acid diester obtained in Synthesis Example 1 was added thereto, and the mixture was stirred as it was for 30 minutes. After returning to room temperature, 0.0742 g (0.252 mmol) of BPDA was added, and the mixture was further diluted with 5.80 g of DMAc, and then stirred for 24 hours. It was 1.34 dL / g when the intrinsic viscosity of this polyimide precursor was measured. Thereafter, 25 ml of DMAc was added to obtain a solid concentration of about 5% by weight, 7.5 ml of acetic anhydride and 3.7 ml of pyridine were added, reacted at 50 ° C. for 2 hours, and left overnight at room temperature. The contents were poured into 200 ml of water, the precipitate was filtered off, washed with methanol, and then vacuum dried at 100 ° C. for 5 hours to obtain 1.39 g of polyimide powder.

The synthesized polyimide powder was dissolved in DMAc to a solid concentration of 20% by weight and applied on a glass plate. This glass plate was heated at 80 ° C. for 1 hour and at 200 ° C. for 1 hour to obtain a polyimide film. This has a glass transition point of 177 ° C., exhibits high solubility at room temperature in organic solvents such as DMAc, N-methyl-2-pyrrolidone, N, N-dimethylformamide, and γ-butyrolactone, and has good moldability. It was confirmed that there was.
The NMR spectrum of this polyimide copolymer measured in DMSO (dimethyl sulfoxide) is shown in FIG.

[Example 2] Preparation of polyimide copolymer of hydroquinone hydrogenated trimellitic acid diester / PMDA / ODA (feeding ratio 9: 1: 10) In a 50 mL three-necked flask, 0.500 g (2.49 mmol) of ODA and DMAc3. 92 g was added and stirred at room temperature to dissolve. This was cooled in an ice bath, 0.831 g (1.76 mmol) of the purified hydroquinone hydrogenated trimellitic acid diester obtained in Synthesis Example 1 was added thereto, and the mixture was stirred as it was for 30 minutes. After returning to room temperature, 0.165 g (0.756 mmol) of PMDA was added and further diluted with 6.21 g of DMAc, and then stirred for 6 hours to synthesize polyamic acid. The intrinsic viscosity of this polyimide precursor was 1.40 dL / g.

A part of the obtained polyamic acid solution was applied on a glass plate and heated at 100 ° C., 200 ° C., and 260 ° C. for 30 minutes in a nitrogen atmosphere to obtain a polyimide film. The glass transition point of this product was 196 ° C.
The NMR spectrum of this polyimide copolymer measured in DMSO (dimethyl sulfoxide) is shown in FIG.

[Comparative Example 1] Production of polyimide of hydroquinone hydrogenated trimellitic acid diester / ODA (feeding ratio 10:10) To a 50 mL three-necked flask, add 0.801 g (4.00 mmol) of ODA and 10.75 g of DMAc at room temperature. Stir and dissolve. To this was added 1.88 g (4.00 mmol) of the purified hydroquinone hydrogenated trimellitic acid diester obtained in Synthesis Example 1, and the mixture was stirred as it was for 1 hour. Next, after dilution with 6.39 g of DMAc, the mixture was continuously stirred for 16 hours. The intrinsic viscosity of the alicyclic polyesterimide precursor was 1.99 dL / g, which was a very high polymer. Thereafter, 13.68 g of DMAc was added for dilution, and 5 ml of acetic anhydride and 2.5 ml of pyridine were added and reacted at 100 ° C. for 4 hours. After cooling, the content was poured into 200 ml of methanol, and the precipitate was separated by filtration, washed with methanol, and then vacuum dried at 100 ° C. for 5 hours to obtain 2.18 g of polyesterimide powder.

  This polyesterimide powder was dissolved in DMAc to a solid concentration of 20% by weight and coated on a glass plate. This glass plate was heated at 80 ° C. for 1 hour and at 200 ° C. for 1 hour to obtain a polyimide film. The glass transition point of this product was 220 ° C.

[Comparative Example 2] Production of polyimide of hydroquinone hydrogenated trimellitic acid diester / PDA (feeding molar ratio 10:10) PDA 0.230 g (2.12 mmol) and DMAc 3.04 g were added to a 50 mL three-necked flask at room temperature. And stirred to dissolve. To this, 1.01 g (2.14 mmol) of purified hydroquinone hydrogenated trimellitic acid diester obtained in Synthesis Example 1 was added, and the mixture was stirred as it was for 30 minutes. Next, the solution was diluted with 5.32 g of DMAc and then stirred for 22 hours. The intrinsic viscosity of the alicyclic polyesterimide precursor was 1.86 dL / g, which was a very high polymer.

  A part of the obtained polyamic acid solution was applied on a glass plate, dried at 80 ° C. for 2 hours in a nitrogen atmosphere, and then heated at 320 ° C. for 1 hour to obtain a polyesterimide film. The glass transition point of this product was 229 ° C.

  All of the polyimide copolymers produced in Examples 1 and 2 described above have a glass transition point of 200 ° C. or lower, and in Comparative Examples 1 and 2, aromatic carboxylic dianhydrides were used alone. Since the value is lower than that in the case, it is considered that molding by extrusion molding or the like is easier.

[Example 3] Preparation of polyimide copolymer of hydroquinone hydrogenated trimellitic acid diester / PMDA / ODA (feeding ratio 1: 9: 10) In a 50 mL three-necked flask, 0.500 g (2.49 mmol) of ODA and DMAc 6.80 g was added and stirred at room temperature to dissolve. To this, 0.118 g (0.252 mmol) of hydroquinone hydrogenated trimellitic acid diester and 0.495 g (2.27 mmol) of PMDA were added and stirred for 4 hours to synthesize polyamic acid. The intrinsic viscosity of this polyimide precursor was measured and found to be 4.01 dL / g.

After diluting the resulting polyamic acid solution with 2.82 g of DMAc, a portion of this was coated on a glass plate and heated at 100 ° C., 200 ° C., and 260 ° C. for 30 minutes in a nitrogen atmosphere, respectively. A membrane was obtained. The glass transition point of this product was 327 ° C., which was higher than that of the conventional alicyclic polyesterimide alone. Moreover, it did not dissolve in DMAc, N-methylpyrrolidone, and cyclohexanone, and was inferior in processability.
In Example 3, although the preparation amount of hydroquinone hydrogenated trimellitic acid diester was small and the solubility in a solvent was lowered, the heat resistance was greatly improved.

2 is an NMR spectrum chart of the polyimide copolymer obtained in Example 1 measured in DMSO. 3 is an NMR spectrum chart of the polyimide copolymer obtained in Example 2 measured in DMSO.

Claims (3)

A copolymer comprising at least an alicyclic polyesterimide unit represented by the general formula (1) and an aromatic polyimide unit.

(In formula (1), A represents a divalent group, X represents a divalent aromatic group, Y represents an aromatic group, and s and t each independently represent 0, 1, or 2. To express.)   The copolymer according to claim 1, wherein the molar ratio of m: n represented by the general formula (1) is 1:20 to 20: 1.   A polyimide film formed by molding the copolymer according to claim 1.

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