KR20130031052A - Polyamic acid-silca hybrid composition, polyimide-silaca hybrid film and method for preparing the sames - Google Patents

Abstract

The present invention relates to a polyamic acid-silica hybrid composition, a method for producing the same, and a polyimide-silica hybrid film and a method for producing the same, which are surface-treated to have excellent compatibility with polyamic acid and manufactured using colloidal silica. The present invention relates to a polyamic acid-silica hybrid composition using a silane sol and a method for producing the same, and to a polyimide-silica hybrid film and a method for producing the same, which are improved in the physical properties of the hybrid composition.

Description

Polyamic acid-silica hybrid composition, polyimide-silica hybrid film, and preparation method thereof {Polyamic Acid-Silca Hybrid Composition, Polyimide-Silaca Hybrid Film and Method for Preparing the Sames}

The present invention relates to a polyamic acid-silica hybrid composition, a polyimide-silica hybrid film, and a manufacturing method thereof in the field of organic-inorganic nano hybrid polyimide.

Polyimide is used in electric and electronic parts, automobile parts, sanitary and food device parts, medical device parts, etc. because of its excellent mechanical properties and good electrical and chemical resistance in a wide temperature range. Particularly in the fields of electrical and electronic components, polyimide films are films for mounting electrical insulators or semiconductor integrated circuits as well as flexible printed circuit boards, various electric motors, transformers and generators due to their excellent heat resistance. It has been put to practical use in a film carrier tape or the like.

However, as the industrial structure has been recently advanced, the necessity for the improvement of polyimide or the development of new composition and the development of new processing technology has been gradually increased due to the increased demand for super heat resistance and functionality. In particular, many studies have been conducted to improve thermal expansion coefficient and dimensional stability of polyimide. For example, attempts are made to improve the dimensional stability of polyimides by using diamines or acids of special structure with low thermal expansion, anhydride components.

However, the use of a compound having a special structure as described above has a problem regarding the availability of raw materials, toxicity, and cost increase, and as an alternative to this, much attention has been focused on the organic-inorganic composite composition. In particular, organic-inorganic nano hybrid materials are capable of overcoming the limitations of existing organic polymer materials and can realize new physical properties.

Attempts have been made to uniformly disperse inorganic fillers in polyamic acid polymers that are precursors of polyimide polymers to improve thermal expansion and dimensional stability of conventional polyimide films. While this process is simple and advantageous in terms of cost, it is difficult to control particle cohesion and to achieve uniform dispersion, as well as film whitening or flexibility, due to the low miscibility of organic polymers with packed particle sizes of tens or hundreds of microns. Degradation of adhesion, electrical properties, etc. had a big problem in the physical properties of the organic-inorganic composite.

Meanwhile, the sol-gel process, which is a method for preparing an organic-inorganic complex, attracts much attention as a possible method for preparing a multicomponent composite by hydrolysis and polycondensation of alkoxy silane (Si (OR) ₄ ) in a polymer matrix. have. However, this method is difficult to control and grow silica by sol-gel process in matrix polymer (polyamic acid) with the cost burden of using expensive alkoxy silane. Silica has a weakness to reduce the durability of the composite material due to the strong stress generated in the dissimilar interface by increasing the contact surface resistance with the resin, and had a limitation in causing a defect or a uniform physical properties of the hybrid material. In addition, alcohol, a by-product produced during the sol-gel process, causes a reverse reaction of the polyamic acid polymer, that is, a polyamic acid polymer chain dissociation, thereby lowering the composite properties and anhydrous to be used as a dehydrating agent for forming a polyimide film through a chemical imidizing agent. As a result of esterification with acetic anhydride, there was a problem of cost increase due to the addition of a dehydrating agent lost by esterification along with the dehydration efficiency of the polyamic acid polymer. It was a fact that there was a problem in the method for commercial production of polyimide-silica hybrid film as an additional cost burden in the sol-gel process using expensive alkoxy silane.

The present invention is intended to provide a polyamic acid-silica hybrid composition, a polyimide-silica hybrid film, and a method for manufacturing the same, which can reduce cost and improve physical properties, which are disadvantages of the organic-inorganic composite.

Accordingly, the present invention provides a polyamic acid polymer (PAA-Silane) having a silane end by reacting (a) a polyamic acid (PAA) prepared by reacting a dianhydride and a diamine and a silane coupling agent. step; (b) preparing a silane sol by adding an organic solvent, distilled water and an acid catalyst to the colloidal silica, followed by hydrolysis and condensation, and then adding a silane coupling agent; (c) preparing a silane sol (PAA-Silane Sol) having a polyamic acid bonded to the surface by combining the silane sol and a polyamic acid polymer having a silane end (PAA-Silane); (d) mixing a silane sol (PAA-Silane Sol) having a polyamic acid bound to the surface and a polyamic acid polymer (PAA) to prepare a polyamic acid-silica hybrid composition. It provides a method for producing a polyamic acid-silica hybrid composition.

According to the above embodiment, when the polyamic acid (PAA) terminal is anhydride in step (a), the silane coupling agent is 3-aminopropyl-triethoxysilane (APTES) or 3-aminopropyl-. The silane coupling agent is 3-glycidoxypropyltriethoxysilane or 3-glycol when 3-ethoxypropyl-diethoxymethylsilane (APMDS) and the terminal of the polyamic acid (PAA) are amines. It may be a glycidoxy propyl methyl ethoxysilane (3-glycidoxy propylmethylsilane, APMDS).

The silane coupling agent of step (b) according to the embodiment may be the same as or different from the silane coupling agent of step (a), 3-aminopropyl-triethoxysilane (3-Aminoproryl-triethoxysilane, APTES), 3 3-Aminopropyl-diethoxymethylsilane (APMDS), 3-glycidoxypropyltriethoxysilane and 3-glycidoxypropylmethylsilane (APMDS) It may be selected from the group consisting of).

In the step (b) according to the embodiment, 1.5 to 2 parts by weight of the silane coupling agent may be added to 100 parts by weight of colloidal silica.

In step (b) according to the embodiment, 0.5 to 2 mol of an organic solvent, 1 to 4 mol of distilled water, and 0.01 to 0.5 mol of an acid catalyst may be added to 1 mol of colloidal silica.

After step (b) according to the embodiment may further comprise the step of solvent-substituted silane sol (Silane Sol) with an organic solvent.

In the step (c) according to the embodiment, 1 to 10 parts by weight of a polyamic acid polymer (PAA-Silane) having a silane terminal may be condensation reaction with respect to 100 parts by weight of silane sol.

In the step (d) according to the embodiment, the polyamic acid polymer (PAA) may be mixed with 5 to 35 parts by weight of the silane sol (PAA-Silane Sol) having a polyamic acid bonded to the terminal.

The present invention also provides a second preferred embodiment, comprising: applying a mixed solution of the polyamic acid-silica hybrid composition and a chemical imidizing agent to a support; Drying the applied liquid mixture to form a coating film; After fixing the coating film to the support, it provides a method for producing a polyimide-silica hybrid film comprising the step of heating and drying.

3 to 10 parts by weight of the chemical imidating agent may be mixed with respect to 100 parts by weight of the polyamic acid-silica hybrid composition according to the embodiment.

The invention also provides, as a third preferred embodiment, a polyamic acid-silica hybrid composition prepared by the above method.

Polyamic acid-silica hybrid composition according to the embodiment may have a silica content of 10 ~ 30wt%.

The present invention also provides, as a fourth preferred embodiment, a polyimide-silica hybrid film prepared by the above method.

According to the present invention, when preparing a polyamic acid-silica hybrid composition, by preparing and using a silane sol having a polyamic acid bonded to the surface, usability and mixing characteristics of the silane sol and polyamic acid polymer can be improved. For this reason, the polyimide-silica hybrid film prepared using the polyamic acid-silica hybrid composition may have excellent heat resistance and mechanical strength, and thus may be used in flexible printed circuit boards, liquid crystal display substrates, and flexible solar cell substrates. In addition, by using inexpensive colloidal silica instead of alkoxy silanes used in the manufacture of silane sol, it is possible to improve the cost competitiveness of the product.

1 illustrates a process for preparing a polyamic acid-silica hybrid composition and a polyimide-silica hybrid film as an embodiment of the present invention.
Figure 2 shows, as an embodiment of the present invention, a process for preparing a polyamic acid polymer having a silane terminal according to the present invention.
3 is an embodiment of the present invention, by preparing a silane sol by hydrolysis condensation reaction of colloidal silica in the presence of an alcohol, a silane coupling agent, and remove the water-soluble alcohol by-product in the resulting silane sol by distillation under reduced pressure, the silane A condensation reaction of a polyamic acid polymer having a sol and a silane end shows a process for preparing a silane sol having a polyamic acid bound to a surface thereof.
4 is an embodiment of the present invention, a polyamic acid-silica hybrid composition is prepared by admixing a silane sol and a polyamic acid polymer having a polyamic acid bound to a surface thereof, and then casting the support onto an imidization catalyst, drying and It shows the process of curing to produce a polyimide-silica hybrid film.
5 and 6 are graphs showing characteristic peaks by polycondensation of imide characteristic peaks and silane sol in the polymer in the FT-IR spectrum of the polyimide-silica hybrid film.

Hereinafter, the present invention will be described in more detail.

The present invention comprises the steps of preparing a polyamic acid polymer (PAA-Silane) having a silane end by reacting a polyamic acid polymer (PAA) prepared by reacting a dianhydride and a diamine and a silane coupling agent; (b) preparing a silane sol by adding an organic solvent, distilled water and an acid catalyst to the colloidal silica, followed by hydrolysis and condensation, and then adding a silane coupling agent; (c) condensing the silane sol with a polyamic acid polymer (PAA-Silane) having a silane end to prepare a silane sol (PAA-Silane Sol) having a polyamic acid bonded to a surface thereof; (d) mixing a silane sol (PAA-Silane Sol) having a polyamic acid bound to the surface and a polyamic acid polymer (PAA) to prepare a polyamic acid-silica hybrid composition. And a method for producing a polyamic acid-silica hybrid composition.

The present invention also comprises the steps of applying to the support a mixed solution of the polyamic acid-silica hybrid composition and the chemical imidizing agent; Drying the applied liquid mixture to form a coating film; And after fixing the coating film to the support, and a method for producing a polyimide-silica hybrid film comprising the step of heating and drying.

As an embodiment of the method for preparing the polyamic acid-silica hybrid composition and the method for producing the polyimide-silica hybrid film, the polyamic acid-silica hybrid composition and the polyimide-silica hybrid film may be prepared as shown in FIG. 1. However, it is not limited thereto.

Step (a) is a process of preparing a polyamic acid polymer (PAA-Silane) having a silane end by reacting a polyamic acid polymer (PAA) prepared by reacting a dianhydride and a diamine with a silane coupling agent. As shown in FIG. 2, a polyamic acid polymer having a silane end may be prepared, but is not limited thereto.

In step (a), the polyamic acid polymer (PAA) may be prepared by copolymerizing dianhydride and diamine in a conventional manner. For example, (1) an aromatic tetracarboxylic dianhydride and an excessively molar amount of an aromatic diamine compound are reacted in an organic polar solvent to obtain a prepolymer having an acid anhydride group at both ends thereof, followed by aromatic tetracarboxylic dianhydride and A method for producing a polyamic acid polymer having a desired molecular weight by adding an aromatic diamine compound such that the aromatic diamine compound is substantially equimolar; Or (2) reacting an aromatic tetracarboxylic dianhydride with an excess molar amount of an aromatic diamine compound in an organic polar solvent to obtain a prepolymer having an amine group at both ends thereof, followed by an aromatic tetracarboxylic dianhydride and an aromatic diamine compound. The polyamic acid polymer (PAA) may be prepared by a method of preparing a polyamic acid polymer having a desired molecular weight by adding an aromatic tetracarboxylic dianhydride to substantially equimolar, but is not limited thereto.

In the step (a), the silane coupling agent may be selected according to the structure of the polyamic acid polymer (PAA). When the terminal of the polyamic acid polymer (PAA) is an anhydride group, the silane coupling agent is 3-aminopropyl-triethoxysilane (APTES) or 3-aminopropyl-diethoxymethylsilane (3-Aminopropyl -diethoxymethylsilane (APMDS), and when the terminal of the polyamic acid polymer (PAA) is an amine, the silane coupling agent is 3-glycidoxypropyltriethoxysilane or 3-glycidoxypropylmethyl. It may be an ethoxysilane (3-glycidoxypropylmethylsilane, APMDS).

Here, when the terminal of the polyamic acid polymer (PAA) is an anhydride group, the polyamic acid polymer may be prepared by reacting 80 to 99% by weight of dianhydride with 1 to 20% by weight of diamine, and the terminal of the polyamic acid polymer (PAA) In the case of this amine, the polyamic acid polymer may be prepared by reacting 1 to 20% by weight of dianhydride with 80 to 99% by weight of diamine.

For example, the polyamic acid polymer having the silane end of step (a) can be synthesized by controlling the ratio of dianhydride and diamine in the presence of a silane coupling agent, that is, fatigue represented by [Formula 1] as dianhydride. Polyamic acid by controlling the ratio of diaminodiphenyl ether (4,4-ODA) and paraphenylenediamine (p-PPD) represented by [Formula 2] and [Formula 3] as metic anhydride (PMDA) and diamine After preparing the polymer, the silane coupling agent may be prepared by encapsulating the terminal with 3-Aminopropyl triethoxysilane (APTES) represented by [Formula 4].

[Formula 1]

      PMDA

[Formula 2]

4,4-ODA

(3)

p- PPD

[Formula 4]

APTES

The polymerization temperature of the diamine and dianhydride for preparing the polyamic acid polymer may be in the temperature range of 0 to 60 ℃, preferably 5 to 50 ℃ in consideration of the polymerization efficiency. When the polyamic acid prepolymer composed of the terminal of the anhydride is used as an intermediate as in the polymerization method (1), the reaction temperature is preferably performed at 30 ° C. or lower, preferably 10 ° C. or lower, and the reaction time is within 10 hours, Preferably less than 5 hours, More preferably, less than 3 hours.

  In the present invention, a silane terminated polyamic acid polymer may be prepared by adding a silane coupling agent during the polymerization of the polyamic acid prepared as described above. As the silane coupling agent, a silane agent capable of chemically bonding with the polyamic acid terminal is preferable, and when the polyamic acid terminal is an anhydride, 3-Aminopropyl triethoxysilane (APTES) or 3-Aminopropyl-diethoxymethylsilane (APMDS) having a reactive amine group, and polyamic acid When the terminal is an amine, it may be 3-glycidoxypropyltriethoxysilane or 3-glycidoxypropylmethylethoxysilane having a reactive epoxy group, but is not limited thereto. Any coupling agent having a reactive functional group at the polyamic acid terminal and inducing a chemical bond with the silane precursor may be used. have.

  For example, anhydride-terminated polyamic acid was prepared and 3-aminopropyl triethoxysilane (APTES) was added as a silane coupling agent to control the end of polyamic acid to induce chemical bonding with silica precursor in sol-gel reaction. can do.

  The amount of silane coupling agent added at this time is preferably adjusted according to the theoretical terminal mole number of the polyamic acid polymer, but it is usually 100 to 500 mol%, preferably 200 to 400 mol% based on the terminal dianhydride functional group calculated quantitatively. More preferably using an amount of 150 to 300 mol% in the reaction yield with the polyamic acid terminal anhydride.

  In addition, in the present invention, when the silane coupling agent is added, the viscosity of the final polyamic acid polymer to be prepared is a target viscosity, and the viscosity of the polyamic acid polymer prepared by copolymerizing the dianhydride and the diamine component in a conventional manner. It is preferred to add when the amount reaches 50 to 95%, preferably 80 to 90% of the target viscosity.

If the silane coupling agent is added too early before the target viscosity, it is difficult to obtain a high molecular weight polyamic acid polymer or when the silane coupling agent is too late, the anhydride terminal reaction efficiency of the silane coupling agent and the polyamic acid polymer decreases. The silane-terminated polyamic acid prepared by the above method is usually 5 to 25% by weight, preferably 10 to 25% by weight, more preferably 15 to 25% by weight of the appropriate molecular weight and solution viscosity You can get it. Further, the preferred number average molecular weight (Mn) of the polyamic acid polymer is 10,000 to 1,000,000, and the viscosity is 10,000 to 40,000 P (rotary viscometer, 25 ° C), preferably 20,000 to 40,000 P.

Step (b) is a step of preparing a silane sol (Silane Sol) by the hydrolysis and condensation reaction in the presence of methyl trimethoxy silane, silane coupling agent by adding an acid catalyst to colloidal silica, Silane sol may be prepared as shown in 3, but is not limited thereto.

0.5 to 2 moles of organic solvent, 1 to 4 moles of water, and 0.01 to 0.5 moles of acid catalyst are added to 1 mole of colloidal silica in step (b), and if the amount of organic solvent, water and acid catalyst is less than The decomposition and condensation reactions do not proceed normally, and if exceeded, there is a problem in that residual byproducts do not participate in the reaction.

An acid catalyst may be added to colloidal silica and hydrolyzed and condensed with 3-Aminopropyl triethoxysilane (APTES) with methyltrimethoxy silane and a silane coupling agent to produce a silane sol.

The amine silane coupling agent preferably has 0.5 to 5% by weight, preferably 1 to 3% by weight more preferably 1.5 to 2% by weight, relative to colloidal silica (solid content 30wt%). The polymerization temperature for preparing the silanol surface-treated with the silane coupling agent is in the range of 0 to 60 ° C, preferably 5 to 50 ° C, and the reaction time is within 24 hours, preferably within 12 hours, more preferably. 8 hours or less is good.

The organic solvent may be a polar solvent such as DMF, DMAc, NMP, and the like is preferably added in an appropriate amount so that the colloidal silica has the same concentration with respect to the water to be replaced.

The acid catalyst may be hydrochloric acid, acetic acid, sulfuric acid, nitric acid, and the like, and the appropriate amount is preferably added so that the aqueous acidity is pH 2.0 to 4.5, preferably PH 3.0 to 4.0 moles, more preferably PH 3.0 to 3.5. Do.

Methyltrimethoxy silane for the surface treatment of colloidal silica preferably has from 1 to 30% by weight, preferably from 5 to 20% by weight and more preferably from 10 to 15% by weight relative to colloidal silica (solid content 30wt%). Do.

In addition, the step (b) may be to add 1.5 to 2 parts by weight of the silane coupling agent with respect to 100 parts by weight of colloidal silica, if the silane coupling agent is less than 1.5 parts by weight silane sol manufacturing process does not proceed as desired If the silane coupling agent is more than 2 parts by weight, there is a problem that the remaining silane coupling agent increases without participating in the reaction.

The silane coupling agent of step (b) may be the same as or different from the silane coupling agent of step (a), and 3-aminopropyl-triethoxysilane (APTES), 3-aminopropyl-die 3-Aminopropyl-diethoxymethylsilane (APMDS), 3-glycidoxypropyltriethoxysilane and 3-glycidoxypropylmethylsilane, methyltrimethoxy silane (Methyltrimethoxysilane, MTMS) may be selected from the group consisting of.

 The polymerization temperature for preparing the silane sol is in the temperature range of 0 to 60 ℃, preferably 5 to 50 ℃ and the reaction time is within 12 hours, preferably within 6 hours, more preferably within 3 hours.

For example, the silane coupling agent used for preparing the silane sol in step (b) is 3-Aminopropyl triethoxysilane (APTES) represented by Formula 4 and methyltrimethoxysilane (MTMS) represented by Formula 5. Can be.

[Formula 4]

APTES

[Chemical Formula 5]

MTMS

The method for preparing a polyamic acid-silica hybrid composition according to the present invention may further include a step of solvent-substituting a silane sol (Silane Sol) with an organic solvent after the step (b).

Due to the solvent replacement, the water-soluble alcohol by-product remaining in the silane sol prepared in step (b) may be removed by distillation under reduced pressure. Maintaining the temperature below 60 ° C under reduced pressure distillation helps maintain the stability of the silane sol. The functional silane sol obtained maintains 20-30 wt% of silica solid content with respect to the reaction solvent. If lower than this, the yield of the silane-terminated polyamic acid condensation reaction is lowered, and if higher, the stability of the functional silane sol is significantly lowered.

Step (c) condensation reaction of the silane sol prepared in step (b) and the polyamic acid polymer (PAA-Silane) having a silane end prepared in step (a), the polyamic acid As a process for producing a bonded silane (PAA-Silane Sol), as an embodiment, as shown in Figure 3 can be prepared a silane sol (PAA-Silane Sol) is a polyamic acid is bonded to the surface However, the present invention is not limited thereto.

The temperature of the reaction system is maintained at 30 ° C. or lower, preferably 20 ° C., and a polyamic acid polymer having a silane end is added, stirred and condensed with the silane sol to prepare a silane sol silane having a polyamic acid bonded to the surface thereof. have. The reaction time is within 12 hours, preferably within 6 hours, more preferably 3 hours.

In this case, 1 to 10 parts by weight of a polyamic acid polymer having a silane end (PAA-Silane) may be condensed with respect to 100 parts by weight of the silane sol, and the polyamic acid polymer having the silane end is less than 1 part by weight. There is a problem in that the surface treatment effect is inferior, and if it exceeds 10 parts by weight, there is a problem such as agglomeration of colloidal particles by an excessive polyamic acid.

The silane sol having a polyamic acid bonded to the surface lowers the interfacial resistance between different species when mixed with the polyamic acid polymer, which is a polyimide precursor, to increase compatibility and to allow a large amount of silica to be contained without degrading polyimide intrinsic properties. There is an advantage.

Silanol having a polyamic acid bound to the surface prepared in step (c) may be represented by the formula (5), but is not limited thereto.

 [Formula 6]

는 폴리이미드의 전구체인 폴리아믹산 중합체를 의미하는 것으로 예를 들면 [화학식 7]로 표시할 수 있으나 이에 제한되는 것은 아니다. 여기서 n은 10 내지 500의 정수이고 m은 10내지 500의 정수이다.
In the above formula

Refers to a polyamic acid polymer that is a precursor of polyimide, for example, but may be represented by [Formula 7], but is not limited thereto. Where n is an integer from 10 to 500 and m is an integer from 10 to 500.

[Formula 7]

Silane end capped Polyamic-acid (PAA-Silane)

Where n is an integer from 10 to 500 and m is an integer from 10 to 500.

Step (d) is a process of preparing a polyamic acid-silica hybrid composition by mixing a polyamic acid (PAA-Silane Sol) and a polyamic acid polymer (PAA) having a polyamic acid bound to a surface thereof. In one embodiment, as shown in FIG. 4, a polyamic acid-silica hybrid composition may be prepared, but is not limited thereto.

At this time, 5 to 35 parts by weight of the polyamic acid polymer (PAA) may be mixed with respect to 100 parts by weight of the silane sol (PAA-Silane Sol) to which the polyamic acid is bound, and the polyamic acid polymer (PAA) is 5 parts by weight. If less than the silica content is difficult to expect the composite physical properties effect, if exceeding 35 parts by weight there is a problem in that the composite physical properties also fall due to local silica agglomeration problem.

The polyamic acid-silica hybrid composition prepared in step (d) may be, for example represented by Formula 8, but is not limited thereto.

[Formula 8]

In the above formula, PAA means a polyamic acid polymer, and for example, may be represented by [Formula 8], but is not limited to a sugar polyamic acid polymer. Where n is an integer from 10 to 500 and m is an integer from 10 to 500.

[Chemical Formula 9]

Where n is an integer from 10 to 500 and m is an integer from 10 to 500.

The present invention relates to a polyamic acid-silica hybrid composition prepared by the manufacturing method as described above, may have a silica content of 10 ~ 30wt% therein.

If the silica content is less than 10wt%, it is difficult to expect the composite properties effect due to the decrease in silica content, if the silica content exceeds 30wt%, there is a problem that the composite properties are also lowered due to local silica aggregation due to miscibility.

The polyamic acid-silica hybrid composition may be prepared into a polyimide-silica hybrid film by imidation by thermal or chemical curing.

In this case, the polyamic acid polymer used for preparing the polyimide-silica hybrid film was copolymerized with an acid dianhydride and a diamine component in a conventional manner to prepare a polyamic acid as a precursor of the polyimide. That is, (1) an aromatic tetracarboxylic dianhydride and an excessively molar amount of an aromatic diamine compound are reacted in an organic polar solvent to obtain a prepolymer having acid anhydride groups at both ends thereof, and then the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially (2) A method for producing a polyamic acid polymer having a desired molecular weight by adding an aromatic diamine compound to a mole, or (2) having an amino group at both ends by reacting an aromatic tetracarboxylic dianhydride with an excess molar amount of an aromatic diamine compound in an organic polar solvent. A method of obtaining a prepolymer and then adding an aromatic tetracarboxylic dianhydride such that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar may be used to prepare a polyamic acid polymer having a desired molecular weight. In the production of polyimide-silica hybrid film, the thermal curing method is a method in which the imidation reaction is carried out by heating only without using a dehydrating agent or an imidization catalyst, and the chemical curing method is a polyamic acid-organic solvent solution, acetic anhydride, A dehydrating agent typified by an acid anhydride and an imidization catalyst typified by tertiary amines such as isoquinoline, β-picoline, pyridine and the like are reacted.

  As in the embodiment of the present invention, when carried out by the chemical curing method, as the dehydrating agent added to the polyamic acid solution, for example, aliphatic acid anhydride, aromatic acid anhydride, N, N'-dialkylcarbodiimide, Lower aliphatic halides, halogenated lower aliphatic halides, halogenated lower fatty acid anhydrides, arylphosphonic acid dihalides, thionylhalides, or mixtures of two or more thereof, of which aliphatic acid anhydrides are preferred. Specifically, as the aliphatic acid anhydride, it is preferable to use acetic anhydride, propionic anhydride, butyric anhydride or a mixture of two or more thereof. The dehydrating agent may be used in a ratio of 1 to 10 molar equivalents, preferably 1.5 to 8 molar equivalents, and more preferably 2 to 5 molar equivalents, relative to the polyamic acid. Outside this range, the chemical imidation ratio may fall below a suitable range or the release property may deteriorate from the support.

In order to advance imidation effectively, it is preferable to use an imidation catalyst simultaneously for a dehydrating agent. Tertiary amines used as imidization catalysts include aliphatic tertiary amines, aromatic tertiary amines, heterocyclic tertiary amines, and the like, of which heterocyclic tertiary amines are preferably used. Quinoline, isoquinoline, β-picolin, pyridine and the like. The imidation catalyst may be used in a ratio of 0.1 to 2 molar equivalents, preferably 0.2 to 1.8 molar equivalents, more preferably 0.3 to 1.5 molar equivalents, relative to the polyamic acid. The manufacturing process (film forming process) of the polyimide film according to the present invention is not particularly limited, and can be produced, for example, by the following process. First, a dehydrating agent and an imidization catalyst are mixed in a copolymerized polyamic acid solution at low temperature. And then applied or cast onto a support such as a support plate, heating drum or endless belt, and then partially cured and dried by heating on a support in a temperature range of 50 to 200 ° C., preferably 70 to 150 ° C. to activate the dehydrating agent and catalyst. Thereafter, a gel film which is a self supporting film is obtained. Then, the ends of the obtained polyamic acid gel film are fixed and heated, and in order to completely imidize the remaining polyamic acid, it is finally heated at a temperature of 200 to 600 ° C. for 3 to 30 minutes to dehydrate closed ring drying. At this time, when the temperature is higher or longer, the film is deteriorated and a problem is likely to occur. On the contrary, when the temperature is lower than this temperature or the time is short, a predetermined effect is hardly expressed. The average thickness of the polyimide film prepared as above may range from 7.5 to 125 μm. In addition, the polyimide film produced as described above has an average thermal expansion coefficient of 5 to 20 ppm / 占 폚 and a tensile modulus of 500 to 700 kg / mm2 in the mechanical direction (MD) and the width direction (TD) at 100 to 200 ° C. And a moisture absorption is 3.0% or less.

Silanol having a polyamic acid bonded to the surface according to the present invention, when mixed with a polyamic acid polymer, which is a polyimide precursor, lowers interfacial resistance between heterogeneous compounds to increase compatibility, and can contain a large amount of silica without degrading polyimide intrinsic properties. Thus, moldings such as polyimide-silica hybrid films or sheets have excellent mechanical strength as well as heat resistance, and thus have excellent characteristics for use in printed boards and substrates for liquid crystal displays. This is a method to solve the problem of deterioration of physical properties caused by a decrease in compatibility, which is a problem of the conventional hybrid technology is to enable the production of a hybrid polyimide composite film of excellent physical properties.

In addition, the present invention is a problem caused by the use of alkoxy silane used to prepare the silane sol in the polyimide-silica nano hybrid manufacturing process, that is, high raw material cost, polyamic acid polymer chain dissociation by alcohol by-products, viscosity drop, curing yield The polyamic acid-silica hybrid composition having excellent physical properties and high value added using a low-cost commercial nano colloidal silane sol as a silica starting material for a hybrid composition to solve the problems such as reduction and polyimide prepared from the composition Silica hybrids and methods for their preparation can be provided.

This is due to the high compatibility and miscibility of the silane sol made of the colloidal silica provided by the present invention and the silane sol in which the polyamic acid is bonded to the surface made by the polyamic acid polymer having the silane end. The silica nano hybrid composition has excellent heat resistance as well as mechanical strength, and thus may be used in flexible printed circuit boards, liquid crystal display substrates, and flexible solar cell substrates.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are not intended to limit the present invention, but are not limited thereto. Measurement of physical properties and various performance evaluations of the films prepared in Examples and Comparative Examples of the present invention were performed by the following method.

Example 1

1-1. Preparation of Polyamic Acid-Silica Hybrid Composition

(a) Preparation of Polyamic Acid Polymer (PAA-Silane) Having a Silane Termination

After 500 ml of the reactor was charged with nitrogen gas, 17.67 g (0.08826 mol) of ODA and 200 g of N, N-dimethylformamide were added to the reactor, followed by stirring at 25 ° C. until complete dissolution. Then 25.68 g (0.11773 mol) of PMDA was added slowly and stirred for 40 minutes. Then, after adding 1.621 g (0.0073 mol) of APTES and stirring for 30 minutes to seal some of the anhydride ends in the polymer with silane, 2.79 g (0.02580 mol) of PPD was slowly added and reacted for 1 hour to polyamide having silane ends. An acid polymer was obtained. The concentration of diamine and acid dianhydride in this reaction solution was 19 wt% with respect to the entire reaction solution. The viscosity of the polyamic acid polymer is 8,000 P (rotary viscometer, 25 ° C).

(b) Preparation of Silane Sol

500 ml of the reactor was charged with nitrogen gas, and then the acidity of the colloidal silane sol was adjusted to pH 3.5 with acetic acid for 100 g (solid size 30%) of colloidal silane (particle size 12 nm), followed by 50 g of ethanol, methyltri 3 g (0.0734 mol) of methoxy silane and 5.53 g (0.0240 mol) of APTES were added and stirred at 25 ° C. for 6 hours. Thereafter, 70 g of N, N-dimethylformamide was added thereto, and distilled under reduced pressure at 60 ° C. to replace the solvent to prepare a silane sol on a DMF solvent surface-treated with APTES.

(c) Preparation of silane sol (PAA-Silane Sol) having a polyamic acid bonded to the surface

2.50 g of a polyamic acid polymer having a silane terminal prepared in (a) (solid content 19wt%) and the silane sol prepared in (b) are reacted at 25 ° C. for 6 hours at a silane sol having a polyamic acid bonded to the surface thereof. Was synthesized. Solids content of the final product was 28.7%.

(d) Preparation of Polyamic Acid-Silica Hybrid Composition

(d) -1. Preparation of Polyamic Acid Polymer (PAA), Precursor of Polyimide

500 ml liter of the reactor was charged with nitrogen gas and then 17.67 g (0.08826 mol) of ODA and 200 g of N, N-dimethylformamide were added to the reactor and stirred at 25 ° C. until complete dissolution. Then 25.68 g (0.11773 mol) of PMDA was added slowly and stirred for 40 minutes. Then, 2.79 g (0.02580 mol) of PPD was slowly added and stirred for 1 hour to prepare a solid content 30 wt% PPD solution, and then in small portions until the desired viscosity (30,000 P, rotary viscometer, 25 ° C.) was reached. Addition to obtain a polyamic acid polymer. The concentration of diamine and acid dianhydride in this reaction solution was 18.5 wt% with respect to the entire reaction solution.

(d) -2. Preparation of Polyamic Acid-Silica Hybrid Composition

The silane having the polyamic acid bonded to the polyamic acid polymer (PAA) prepared in (d) -1 and the surface prepared in (c) so that the content of silica in the final polyamic acid-silica hybrid composition is 10wt%. PAA-Silane Sol was quantified and stirred and mixed to prepare a polyamic acid-silica hybrid composition.

1-2. Preparation of Polyimide-Silica Hybrid Film

5 molar equivalents of acetic anhydride (AA) (based on polyamic acid) and 1 molar equivalent of isoquinoline (IQ) based on the polyimide equivalent ratio of the polyamic acid-silica hybrid composition prepared in 1-1 above as a chemical imidating agent 1 molar equivalent), and the mixed solution was cast on a aluminum sheet in a uniform thickness and dried stepwise at 90 ° C for 42 seconds, 110 ° C for 2 minutes, and 130 ° C for 3 minutes and 12 seconds. Subsequently, the obtained polyamic acid coating film (gel film) was peeled off from an aluminum plate, and the coating film was pinned to a support frame, and then heated at 250 ° C. for 5 minutes and at 450 ° C. for 5 minutes to dehydrate and ring-close dry to obtain a thickness of 25 μm. Polyimide-silica hybrid film was obtained.

Example 2

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared in the same manner as in Example 1 except that the content of the final silica in the polyamic acid-silica hybrid composition was 20 wt%.

Example 3

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared in the same manner as in Example 1 except that the content of the final silica in the polyamic acid-silica hybrid composition was 30 wt%.

Example 4

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared such that the content of the final silica in the polyamic acid-silica hybrid composition prepared by the same process as in Example 1 was 10 wt%, and in step (c) 5.32 g (0.0240 mol) of APTES was added so that the content of APTES was 10 mol% with respect to TEOS during the synthesis of the silane sol having the polyamic acid.

Example 5

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared in the same manner as in Example 4 except that the content of the final silica in the polyamic acid-silica hybrid composition was 20 wt%.

Example 6

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared in the same manner as in Example 4 except that the content of the final silica in the polyamic acid-silica hybrid composition was 30 wt%.

Example 7

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared such that the content of the final silica in the polyamic acid-silica hybrid composition prepared by the same process as in Example 1 was 10 wt%, and in step (c) 10.63 g (0.0480 mol) of APTES was added so that the content of APTES was 20 mol% with respect to TEOS during the synthesis of the silane sol having the polyamic acid.

Example 8

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared in the same manner as in Example 7, except that the content of the final silica in the polyamic acid-silica hybrid composition was 20 wt%.

Example 9

A polyamic acid-silica hybrid composition and a polyimide-silica hybrid film were prepared in the same manner as in Example 7, except that the content of the final silica in the polyamic acid-silica hybrid composition was 30 wt%.

Comparative Example 1

Example 1 A polyimide film was prepared in the same manner as in Example 1, except that silane sol having a polyamic acid bound was not added to the surface prepared in step (c).

Comparative Examples 2 to 4

Using only colloidal silica, hybrid compositions and polyimide-silica hybrid films were prepared such that the silica content was 10, 20, 30 wt% as in Examples 1, 2, and 3.

Comparative Example 5 to Comparative Example 7

A polyimide-silica hybrid film was prepared in the same manner as in Examples 1, 2, and 3 to have a silica content of 10, 20, and 30 wt%, but the colloidal silane surface-treated with silane using only APTES except polyamic acid as the colloidal silane sol. Sol was used.

Comparative Example 8-13

In the same manner as in Examples 1, 2, and 3, a polyimide-silica hybrid film having a silica content of 10, 20, and 30 wt% was prepared, but as colloidal silane sol, colloidal silane with different amounts of APTES / colloidal silane sol except polyamic acid was added. Silanazole was used.

FT-IR analysis was performed to confirm the synthesis of silane sol (PAA-Silane Sol) having a polyamic acid bonded to the surface thereof. For the polyimide films prepared in Examples 1 to 9 and Comparative Examples 1 to 7, The elongation, thermal expansion coefficient (CTE) and glass transition temperature (Tg, ° C.) were measured as shown in Table 1, and the results are shown in Table 1.

(1) Infrared Absorption Spectroscopy (FT-IR)

   Device: Nicolet 380 (Thermo Scientific)

(2) tensile strength, elongation, elastic modulus

  Device: UTM (Instron)

  Sample: width 15mm, length 100mm

  Tensile Speed: 100 mm / min

(3) Coefficient of thermal expansion

  Device: TMA-2940 (TA)

  Temperature: 20 ~ 400 ℃

  Heating rate: 10 ℃ / min

  Sample size: 5 ㅧ 20 ㎜

  Load: 3 g

(4) Glass transition temperature

  The glass transition temperature present on the characteristic peak at the 2nd run was measured.

  Device: DSC-2940 (TA)

  Temperature: 20 ~ 400 ℃

  Heating rate: 10 ° C / min

(5) transparency

    Device: 日本 電 色 Haze / Tubidity Meter (NDH-5000W)

    Sample: A4 Size

Method: measuring total light transmittance

Silica (%) % By weight
(APTES / colloidal silane sol) PAA-Si
Surface treatment thickness
(μm) Seal
burglar
(Mpa) Elongation
(%) Modulus
(Gpa) Tg
(℃) CTE
(100 ~
200 ℃) transparency Example 1 10 5.5 O 32 222 60 3.8 431 18 T Example 2 20 5.5 O 28 243 52 4 432 17 T Example 3 30 5.5 O 25 257 50 4.1 421 16 T Example 4 10 9 O 34 190 58 4 422 18 T Example 5 20 9 O 26 245 55 4.6 442 16 T Example 6 30 9 O 30 265 47 4.7 431 15 T Example 7 10 18 O 32 247 60 4.1 420 20 T Example 8 20 18 O 34 282 58 4.5 425 18 T Example 9 30 18 O 25 291 52 4.8 443 16 T Comparative Example 1 0 0 X 28 234 76 3.5 452 21 T Comparative Example 2 10 0 X 27 201 43 3.5 351 20 T Comparative Example 3 20 0 X 22 200 32 3.7 403 18 O Comparative Example 4 30 0 X 25 200 32 3.8 422 17 O Comparative Example 5 10 5.5 X 32 202 35 3.6 381 21 T Comparative Example 6 20 5.5 X 28 204 28 3.7 418 18 T Comparative Example 7 30 5.5 X 25 211 13 3.8 419 16 O Comparative Example 8 10 9 X 28 215 22 3.6 419 18 T Comparative Example 9 20 9 X 25 243 21 4.1 433 16 T Comparative Example 10 30 9 X 27 250 20 4.2 427 15 O Comparative Example 11 10 18 X 28 230 32 3.6 418 20 T Comparative Example 12 20 18 X 26 243 25 4.2 427 18 T Comparative Example 13 30 18 X 26 244 20 4.2 437 16 O

As a result of measuring physical properties, in order to confirm the synthesis of silanol having a polyamic acid bound to the surface with respect to infrared absorption spectroscopy (FT-IR), anhydride of a reactive amine functional group which is a silane coupling agent and an anhydride terminal of a polyamic acid chain terminal It was necessary to confirm the reaction with the carbonyl functional group.

However, the amount of APTES added for the terminal encapsulation of the anhydride-terminated polyamic acid is very small relative to the polyamic acid, and their reactive characteristic peaks by FT-IR are difficult to analyze because they are buried in other characteristic peaks or the change is weak. It was not enough for the following. The synthesis reaction was confirmed by analyzing the FT-IR reaction peak of the sample by the modeling test of PMDA and APTES.

In other words, 1 mol PMDA and 2 mol APTES were synthesized in the presence of DMF solvent at room temperature and nitrogen atmosphere and then dried for 48 hours in 100 ℃ and air. Carbonyl (C = O) peaks and imide carbonyl (C = O) peaks were confirmed to confirm their reactivity. That is, shown in FIG. 5 1885 - most APTES amide (NH ₂₎ characteristic peaks at 1725cm ^-1 and a peak of the characteristic anhydride PMDA and 3335cm ^-1 disappears by reaction thereof in a 1660cm ^-1 amide carbonyl (C as described The streching vibration characteristic peak of = O) and the streching vibration characteristic peak of imide carbonyl (C = O) at 1778cm ^-1 were confirmed.

In addition, it can be seen from the results of Table 1 that the silane sol having a polyamic acid bonded to the surface has a low elongation decrease due to the increase of silica filling amount in the composite, and thus a film having high toughness with polyimide can be produced. have. This is due to the high compatibility and miscibility with the polyamic acid polymer of the silanazole having a polyamic acid bonded to the surface provided by the present invention in the polyamic acid-silica hybrid composition, which is excellent in heat resistance and mechanical strength. It can be seen that it can be used for printed boards, liquid crystal display substrates, flexible solar cell substrates, and the like.

Although the exemplary embodiments of the present invention have been exemplified above, the present invention is not limited to the above-described specific preferred embodiments, and the present invention may be commonly used in the art without departing from the gist of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

Claims (13)

(a) preparing a polyamic acid polymer (PAA-Silane) having a silane end by reacting a polyamic acid (PAA) prepared by reacting a dianhydride and a diamine with a silane coupling agent;
(b) preparing a silane sol by adding an organic solvent, distilled water and an acid catalyst to the colloidal silica, followed by hydrolysis and condensation, and then adding a silane coupling agent;
(c) condensing the silane sol with a polyamic acid polymer (PAA-Silane) having a silane end to prepare a silane sol (PAA-Silane Sol) having a polyamic acid bonded to a surface thereof;
(d) mixing a silane sol (PAA-Silane Sol) having a polyamic acid bound to the surface and a polyamic acid polymer (PAA) to prepare a polyamic acid-silica hybrid composition. ,
Method for producing a polyamic acid-silica hybrid composition.
The method of claim 1,
When the polyamic acid (PAA) terminal in step (a) is an anhydride, the silane coupling agent is 3-aminopropyl-triethoxysilane (APTES) or 3-aminopropyl-diethoxymethylsilane ( 3-Aminopropyl-diethoxymethylsilane, APMDS)
When the terminal of the polyamic acid (PAA) is an amine, the silane coupling agent is 3-glycidoxypropyltriethoxysilane or 3-glycidoxypropylmethylsilane (APMDS). It is characterized by
Method for producing a polyamic acid-silica hybrid composition.
The method of claim 1,
The silane coupling agent of step (b) may be the same as or different from the silane coupling agent of step (a), and 3-aminopropyl-triethoxysilane (APTES), 3-aminopropyl- Group consisting of 3-Aminopropyl-diethoxymethylsilane (APMDS), 3-glycidoxypropyltriethoxysilane and 3-glycidoxypropylmethylsilane (APMDS) Method for producing a polyamic acid-silica hybrid composition, characterized in that selected from.
The method of claim 1,
In the step (b), 1.5 to 2 parts by weight of the silane coupling agent is added to 100 parts by weight of colloidal silica, the method for producing a polyamic acid-silica hybrid composition.
The polyamic acid-silica according to claim 1, wherein 0.5-2 mol of an organic solvent, 1-4 mol of distilled water, and 0.01-0.5 mol of an acid catalyst are added to 1 mol of colloidal silica in step (b). Method for preparing a hybrid composition.
The method of claim 1, further comprising the step of solvent-substituting a silane sol (Silane Sol) with an organic solvent after the step (b).
[Claim 2] The polyamic acid of claim 1, wherein in the step (c), 1 to 10 parts by weight of a polyamic acid polymer (PAA-Silane) having a silane end is condensed with respect to 100 parts by weight of silane sol (Silane Sol). Method for producing a silica hybrid composition.
The method of claim 1,
In the step (d), polyamic acid-silica hybrid, characterized in that 5 to 35 parts by weight of a polyamic acid is bonded to the end of the polyamic acid polymer (PAA) is combined with the polyamic acid (PAA-Silane Sol) Method of Preparation of the Composition.
Applying to the support a mixed solution of a polyamic acid-silica hybrid composition prepared by the method of any one of claims 1 to 8 and a chemical imidating agent;
Drying the applied liquid mixture to form a coating film;
After fixing the coating film to the support, comprising the steps of heating and drying, polyimide silica hybrid film manufacturing method.
10. The method of claim 9,
A method for producing a polyimide-silica hybrid film, characterized in that 3 to 10 parts by weight of a chemical imidating agent is mixed with respect to 100 parts by weight of the polyamic acid-silica hybrid composition.
A polyamic acid-silica hybrid composition prepared by the method of any one of claims 1 to 8.
The polyamic acid-silica hybrid composition according to claim 11, wherein the silica content is 10-30 wt%.
A polyimide-silica hybrid film prepared by the method of claim 9 or 10.

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