JP2007034284A - Polyimide resin composition and electric insulated wire or liquid crystal aligning agent using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyimide resin composition excellent in wear resistance and moldability, and also to provide an electric insulated wire or a liquid crystal aligning agent using the same. <P>SOLUTION: The polyimide resin composition comprises at least one polymer selected from a polyamic acid and a polyimide each of which is a reaction product of a tetracarboxylic acid dianhydride and a diamine compound, and an alicyclic epoxy compound as constituents. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyimide resin composition excellent in wear resistance, an insulated wire using the same, or a liquid crystal aligning agent.

  Conventionally, since polyimide has high mechanical strength, heat resistance, and solvent resistance, it is known in various fields. Among them, polyimides having an aromatic ring have been studied so far ( For example, see Patent Document 1 and Patent Document 2).

  As the polyimide having an aromatic ring, a polyimide having an aromatic ring is often used as a composition of an insulated wire that requires wear resistance or in a liquid crystal alignment film.

  In recent years, particularly when the light output of a light source is large, such as a liquid crystal projector, high light resistance of a member used for a liquid crystal display is required.

  In general, aliphatic and alicyclic polyimides are known as highly light-resistant materials, that is, highly transparent polyimides (see, for example, Patent Document 3, Patent Document 4, and Non-Patent Document 1). A liquid crystal alignment film for improving color purity is also known (see, for example, Patent Document 5).

  As a liquid crystal display element using the liquid crystal alignment film, a liquid crystal alignment film is formed on the surface of the substrate on which the transparent conductive film is provided to form a liquid crystal display element substrate, and the two sheets are arranged to face each other and the gap A TFT liquid crystal panel in which a liquid crystal layer is formed in a cell having a sandwich structure and the liquid crystal display element is operated by driving a TFT is widely used. The orientation of the liquid crystal molecules in these liquid crystal display elements is usually formed by applying a so-called rubbing process in which the surface of the coating made of organic polymer is rubbed in a fixed direction with a roll in which a cloth made of fiber such as rayon or cotton is wound. Expressed by the liquid crystal alignment film.

  It is also known to introduce additives in order to improve the resistance to rubbing treatment. (For example, see Patent Literature 6, Patent Literature 7, Patent Literature 8, Patent Literature 9, and Patent Literature 10).

Japanese Unexamined Patent Publication No. 60-6726 JP 2000-313804 A JP-A-5-301958 JP-A-8-003314 JP 2000-250047 A JP 2002-357831 A JP 10-333153 A Japanese Patent Laid-Open No. 10-46151 Japanese Patent No. 3206401 Japanese Patent Laid-Open No. 58-30728 Imai, Tatsuo, Yokota, Rikio; “Latest Polyimides: Fundamentals and Applications”, NTS, Publication Date; January 28, 2002, p. 338-402

  Therefore, a glycidyl-based additive (N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane or the like) described in Patent Document 7 or Patent Document 9 is added to polyimide containing a large amount of an alicyclic structure. When introduced and intensively studied, by introducing the additive, wear resistance and resistance to rubbing treatment as a liquid crystal aligning agent was improved, but the compatibility with polyimide containing a large amount of alicyclic structure was poor, As the polyimide resin composition, the formability of the insulated wire was poor, and as the liquid crystal aligning agent, the liquid crystal molecules were poorly aligned.

  Then, in view of the said subject, in this invention, it aims at providing the polyimide resin composition excellent in abrasion resistance and a moldability, and the insulated wire or liquid crystal aligning agent using the same.

  In order to achieve the above object, the invention of claim 1 is at least one polymer selected from polyamic acid and polyimide, which is a reaction product of a tetracarboxylic dianhydride and a diamine compound, and the polymer is an alicyclic structure. It is a polyimide resin composition characterized by comprising a polymer having an alicyclic epoxy compound as a constituent component.

  The invention according to claim 2 is the polyimide resin composition according to claim 1, wherein the alicyclic structure of the alicyclic epoxy compound is a cyclohexane ring structure.

  A third aspect of the present invention is the polyimide resin composition according to the first or second aspect, wherein the alicyclic epoxy compound is a compound represented by Chemical Formula 1.

(In the formula, R ₁ represents a monovalent organic group, and R ₂ represents hydrogen or an organic group.)
The invention according to claim 4 is the polyimide resin composition according to any one of claims 1 to 3, wherein the polyimide resin composition contains at least one acid anhydride or amine compound having an alicyclic structure. is there.

  The invention according to claim 5 is an insulated wire obtained by applying the polyimide resin composition according to claims 1 to 4 to an insulating material of an insulated wire.

  The invention of claim 6 is characterized in that it comprises at least one polymer selected from polyamic acid and polyimide, which is a reaction product of tetracarboxylic dianhydride and diamine compound, and an alicyclic epoxy compound as constituent components. It is a liquid crystal aligning agent.

  The invention according to claim 7 is the liquid crystal aligning agent according to claim 7, wherein the polymer has an alicyclic structure.

  The invention according to claim 8 is the liquid crystal aligning agent according to claim 6 or 7, wherein the alicyclic structure of the alicyclic epoxy compound is a cyclohexane ring structure.

  The invention according to claim 9 is characterized in that the alicyclic epoxy compound is

(In the formula, R ₁ represents a monovalent organic group, and R ₂ represents hydrogen or an organic group.)
The liquid crystal aligning agent according to claim 6, wherein the liquid crystal aligning agent is a compound represented by the formula:

  The invention according to claim 10 is characterized in that the liquid crystal aligning agent contains at least one acid anhydride having an alicyclic structure or an amine compound having an alicyclic structure. It is an alignment agent.

  Thus, the present invention is a polyimide resin composition comprising as constituent components at least one polymer selected from polyamic acid, which is a reaction product of tetracarboxylic dianhydride and a diamine compound, and polyimide, and an alicyclic epoxy compound. By using this as a covering material for an insulated wire, wear resistance and formability are improved, and when a liquid crystal aligning agent is used, rubbing resistance can be improved.

  Since the polyimide resin composition of the present invention contains an epoxy as a compound, it can be excellent in wear resistance, and has a polymer having an alicyclic structure and an alicyclic epoxy compound as constituent components, Since they have the same alicyclic structure, they have good compatibility and excellent moldability.

  Therefore, by applying the polyimide resin composition to an electric wire insulating material, an insulated electric wire excellent in extrusion moldability and wear resistance can be provided.

  Moreover, by applying to a liquid crystal aligning agent, it is possible to provide a liquid crystal alignment film having high transparency and excellent alignment of liquid crystal molecules with few rubbing scratches even by rubbing treatment.

  Hereinafter, a preferred embodiment of the present invention will be described.

  Polyamic acid and / or polyimide can be synthesized by reacting a tetracarboxylic dianhydride and a diamine compound with the polyimide resin composition constituting the covering material of the insulated wire or the liquid crystal aligning agent of the present invention. Among such tetracarboxylic dianhydrides and diamine compounds, at least one kind preferably has an alicyclic structure.

  Examples of the tetracarboxylic dianhydride constituting the polyamic acid and / or polyimide include alicyclic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride.

  Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetra Carboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid Anhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic acid Anhydride and the like.

  Examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride.

  As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic Acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetra Examples thereof include carboxylic dianhydride and 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride.

  These tetracarboxylic dianhydrides can be used singly or in combination of two or more.

  Examples of the diamine compound component constituting the polyamic acid and / or polyimide used in the present invention include an alicyclic diamine compound, an aliphatic diamine, and an aromatic diamine compound.

  Examples of the alicyclic diamine compound include 1,3-bis (aminomethyl) cyclohexane, 1,2-cyclohexanediamine compound, 1,3-cyclohexanediamine compound, 3,3′-dimethyl-4,4′-diamino-dicyclohexyl. Methane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro- (5,5) undecane 4,4′-diamino-dicyclohexylmethane, 1,4-bis (3- Aminopropyl) piperazine and the like.

Examples of aliphatic diamines include hexamethylenediamine compounds, 1,2-diaminotetradecane, 1,2-diaminoheptadecane, 1,2-diaminooctadecane, 1,9-diaminononane, and 2,2-dimethyl-1,3-propane. Examples include diamine compounds, 1,11-diaminoundecane, aminopropyl-terminated dimethyl silicone (Low MW), aminopropyl-terminated dimethyl silicone (High MW), etc. Examples of aromatic diamine compounds include p-phenylenediamine compounds. 3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl Ether, 1,3-bis- (4-aminophenoxy) benzene, 1,3-bis- (3-aminophenoxy) benzene, 4,4′-diaminodiphenyl sulfone, bis {4- (3-aminophenoxy) phenyl } Sulfone, 2,2′-bis {4- (4-aminophenoxy) phenyl} propane, 2-dodecyloxy-1,4-diaminobenzene, 2,2′-bis {4- (4-aminophenoxy) phenyl } Hexafluoropropane, 4,4′-diaminobenzanilide and the like.

  These diamine compounds can be used singly or in combination of two or more.

  The total aromatic weight of the polyamic acid and / or polyimide used in the present invention is preferably 20% or less, and thus the transparency of the liquid crystal aligning agent is improved by 20% or less. be able to.

  Here, the aromatic weight is obtained by dividing the molecular weight of the aromatic ring in the polyamic acid and / or polyimide (however, the molecular weight of the organic group bonded to the aromatic ring is not included) by the molecular weight of the entire polyamic acid and / or polyimide. Value.

  The polyimide resin composition of the present invention is characterized in that the alicyclic epoxy compound represented by Chemical Formula 1 is contained.

  Examples of the alicyclic epoxy compound include vinylcyclohexene monooxide-1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, D-2,2,6. -Trimethyl-2,3-epoxybicyclo [3,1,1] heptane, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate, 2-methyl-3,4-epoxycyclohexylmethyl-2 '-Methyl-3', 4'-epoxycyclohexylcarboxylate, 2,3-epoxycyclopentane-2 ', 3'-epoxycyclopentane ether, ε-caprolactone modified 3,4-epoxycyclohexylmethyl 3', 4 ' -Epoxycyclohexane Bokireto, 1,2: 8,9 diepoxy limonene, hydrogenated bisphenol A diglycidyl ethers, such as hexahydrophthalic acid diglycidyl esters, but are not limited thereto.

  Here, the addition amount of the alicyclic epoxy compound is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the polyamic acid and / or polyimide.

  In order to increase the reactivity of the alicyclic epoxy compound, a curing agent having an alicyclic structure may be added to the polyimide resin composition of the present invention. Such alicyclic curing agents include hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, 1,2-cyclohexanediamine, hydrogenated pyromellitic dianhydride, 1,3-cyclohexanediamine, 1,4 -Although cyclohexanediamine etc. are mentioned, it is not limited to this.

  The addition amount of the curing agent is preferably added so that the acid equivalent of the acid anhydride and the amine equivalent of the amine are 0.5 to 1.5 equivalent in total with respect to 1 epoxy equivalent of the alicyclic epoxy compound. .

  The polyimide used in the present invention can be synthesized by dissolving a tetracarboxylic dianhydride and a diamine compound in an organic solvent and directly imidizing. The mixing ratio of tetracarboxylic dianhydride and diamine compound is preferably a molar ratio of 1: 1. The imidization can be performed by heating or in the presence of an imidization catalyst. The reaction temperature when imidizing by heating is preferably 80 ° C to 200 ° C, more preferably 120 ° C to 180 ° C.

  Furthermore, examples of the organic solvent include N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, sulfolane, anisole, dioxolane, butyl cellosolve acetate, lactone, and the like, which can be used alone. Two or more types may be mixed and used.

  Usually, the amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic dianhydride and the diamine compound is 5 to 40% by weight based on the total amount of the reaction solution.

  The obtained polyimide solution is put into a poor solvent to precipitate a polymer.

  Examples of the poor solvent include water, alcohols, ketones, ethers, esters, halogenated hydrocarbons, hydrocarbons, and more specifically, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexane. Xanol, 1,4-butanediol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, diethyl malonate, diethyl ether, methyl cellosolve, ethyl cellosolve, butyl cellosolve, tetrahydrofuran, dichloromethane, hexane, heptane, octane, Examples thereof include benzene, toluene, xylene and the like.

  The obtained polymer powder can be dried under reduced pressure to obtain a desired polyimide resin powder. The drying temperature is preferably determined in consideration of the boiling point of the poor solvent used above.

  The insulated wire obtained using the polyimide resin composition of the present invention can be produced, for example, by the following method.

  As a conductor used for the insulated wire of the present invention, a copper wire may be used as a single wire, or may be used as a plurality of stranded wires or knitted wires, and the copper wire may be subjected to doweling or electrolytic tin plating. Good. Moreover, the cross-sectional shape of the conductor is not limited to a circle, and there is no problem even if it is a rectangular shape obtained by slitting from a plate-like copper plate or rolling a round wire. The insulated wire of the present invention is a wire having the polyimide resin composition as a conductor coating layer.

  A well-known method can be used for the manufacturing method of the insulated wire of this invention. That is, the polyimide resin composition can be obtained by extruding a single or plural conductors using a normal extrusion molding line.

  Moreover, the liquid crystal display element obtained by using the polyimide resin composition of this invention as a liquid crystal aligning agent can be manufactured, for example with the following method.

  After applying a liquid crystal aligning agent with a solid content concentration of 3% by weight on a glass substrate with ITO (Indium-Tin-Oxid) transparent electrode by spin coating, it is temporarily dried at 80 ° C. and then finally dried at 250 ° C. A liquid crystal alignment film is formed.

  Next, the coating film is rubbed in a certain direction with a roll around which fibers such as rayon and cotton are wound.

  Two substrates with a liquid crystal alignment film formed by the above method are arranged to face each other with a gap between the two substrates so that the rubbing directions are orthogonal or antiparallel, and the peripheral portions of the two substrates are arranged. Bond with a sealant.

  Thereafter, liquid crystal is injected and sealed in the gap between the two substrates to produce a liquid crystal cell.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

  First, Examples 1 to 8 and Comparative Examples 1 to 3 when the polyimide resin composition of the present invention is used as a liquid crystal aligning agent will be described.

Example 1;
To a 300 ml separable four-necked flask equipped with a stirrer, a ball condenser equipped with a trap with a silicon cock was attached, and bicyclo (2,2,2) oct-7-ene-2,3,5,6- 7.45 g of tetracarboxylic dianhydride (hereinafter referred to as BCD), 4.42 g of 4,4′-diamino-dicyclohexylmethane (hereinafter referred to as DAHM), 0.97 g of p-phenylenediamine (hereinafter referred to as PPD), After adding 0.34 g of γ-caprolactone, 0.47 g of pyridine, 47.04 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) and 9.41 g of toluene, the mixture was stirred at room temperature in a nitrogen atmosphere for 10 minutes, and then 180 ° C. And stirred for about 10 hours to obtain a reaction solution. The water generated during the reaction was distilled out of the reaction system by azeotropy with toluene.

  Next, the resulting varnish was poured into methanol, and the resulting precipitate was pulverized, filtered, washed and dried under reduced pressure to obtain a polyimide powder.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 0.59 g of 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexenecarboxylate was further added.

Example 2;
In a flask similar to Example 1, cyclobutanetetracarboxylic dianhydride (hereinafter referred to as CBDA) 5.88 g, 1,3-bis (3-aminophenoxy) benzene (hereinafter referred to as APB) 2.63 g, DAHM4 .42 g, γ-caprolactone 0.34 g, pyridine 0.47 g, NMP 47.4 g, and toluene 9.48 g were added, respectively, and then the same treatment as in Example 1 was performed to obtain a polyimide powder.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 1.18 g of 3,4-epoxycyclohexylmethyl acrylate was further added.

Example 3;
In a flask similar to that in Example 1, 1,30,4-cyclopentanetetracarboxylic dianhydride (hereinafter referred to as CPDA) 6.30 g, DAHM 4.42 g, γ-caprolactone 0.34 g, pyridine 0.47 g, NMP42.44g and toluene 8.49g were added, respectively, and the same process as Example 1 was followed, and the polyimide powder was obtained.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 0.53 g of 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexenecarboxylate was further added.

Example 4;
To the same flask as in Example 1, 7.45 g of BCD, 4.42 g of DAHM, 0.97 g of PPD, 0.34 g of γ-caprolactone, 0.47 g of pyridine, 47.04 g of NMP and 9.41 g of toluene were added, respectively. The polyimide powder was obtained through the same treatment.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and further 0.59 g of 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate and hexahydrophthalic anhydride 72 g was added.

Example 5;
CBDA 5.88 g, APB 2.63 g, DAHM 4.42 g, γ-caprolactone 0.34 g, pyridine 0.47 g, NMP 47.4 g, and toluene 9.48 g were added to the same flask as in Example 1, and then Example 1 and The polyimide powder was obtained through the same treatment.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 1.18 g of 3,4-epoxycyclohexylmethyl acrylate and 1.09 g of methylhexahydrophthalic anhydride were added.

Example 6;
In a flask similar to Example 1, 9.31 g of 4,4′-oxydiphthalic anhydride, 7.15 g of 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane (hereinafter referred to as DMHM), γ-caprolactone 0 .34 g, 0.47 g of pyridine, 61.52 g of NMP, and 12.3 g of toluene were added, respectively, and then the same treatment as in Example 1 was performed to obtain a polyimide powder.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 1.18 g of 3,4-epoxycyclohexylmethyl acrylate and 1.09 g of methylhexahydrophthalic anhydride were added.

Example 7;
To the same flask as in Example 1, CPDA 6.30 g, DMHM 5.01 g, 1,3-diaminopropane-2-dodecane 2.27 g, γ-caprolactone 0.34 g, pyridine 0.47 g, NMP 50 g, and toluene 10 g were added. Thereafter, the same treatment as in Example 1 was performed to obtain a polyimide powder.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 0.53 g of 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate and hexahydrophthalic anhydride 72 g was added.

Example 8;
BCD 7.45 g, DAHM 6.31 g, γ-caprolactone 0.34 g, pyridine 0.47 g, NMP 50.72 g, and toluene 10.14 g were added to the same flask as in Example 1, and then the same treatment as in Example 1 was performed. A polyimide powder was obtained.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and further 1.27 g of 2,3-epoxycyclopentane-2 ′, 3′-epoxycyclopentane ether and 0.80 g of 1,4-cyclohexanediamine. Was added.

Comparative Example 1;
To the same flask as in Example 1, 6.30 g of CPDA, 6.31 g of DAHM, 0.34 g of γ-caprolactone, 0.47 g of pyridine, 46.12 g of NMP, and 9.22 g of toluene were added, respectively, and then the same as in Example 1. Through the treatment, polyimide powder was obtained.

  In the same manner as in Example 1, the obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and further, 0.59 g of 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate was obtained. 0.72 g of hexahydrophthalic anhydride was added.

Comparative Example 2;
To the same flask as in Example 1, 6.30 g of CPDA, 6.31 g of DAHM, 0.34 g of γ-caprolactone, 0.47 g of pyridine, 46.12 g of NMP, and 9.22 g of toluene were added, respectively, and then the same as in Example 1. Through the treatment, polyimide powder was obtained.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 1.15 g of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane was further added.

Comparative Example 3;
To the same flask as in Example 1, 7.45 g of BCD, 6.31 g of DAHM, 0.34 g of γ-caprolactone, 0.47 g of pyridine, 46.12 g of NMP, and 9.22 g of toluene were added, respectively, and then the same as in Example 1. Through the treatment, polyimide powder was obtained.

  The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 1.15 g of N, N, N ′, N′-tetraglycidyl-m-xylylenediamine was further added.

  The polyimide resin synthesized by Examples 1-8 and Comparative Examples 1-3 was adjusted with the following method, and the liquid crystal aligning agent was obtained. Next, the following method for forming a liquid crystal alignment film and evaluation items for the liquid crystal alignment film were implemented, and the evaluation results are shown in Table 1.

[Method of forming liquid crystal alignment film]
After applying a liquid crystal aligning agent having a solid content concentration of 3% by weight on a glass substrate with an ITO (Indium-Tin-Oxid) transparent electrode by a spin coating method, it was temporarily dried at 80 ° C. and then finally dried at 200 ° C. A liquid crystal alignment film having a thickness of about 50 nm was obtained.

[Evaluation of rubbing resistance of liquid crystal alignment film]
The liquid crystal alignment film formed by the above-described method was rubbed with a rubbing apparatus RM-50 manufactured by Etch Sea Co., Ltd. at a rubbing density of 100 and a roll pushing amount of 0.4 mm. The substrate surface was observed with an optical microscope, and scratches due to rubbing were counted. When the number of scratches due to rubbing was less than 20, O, and 20 or more were marked X.

[Method for manufacturing liquid crystal display element]
A rubbing process is performed in which the liquid crystal alignment film formed by the above method is rubbed in a fixed direction with a rubbing apparatus including a roll around which a cloth made of rayon is wound. Next, the two liquid crystal alignment films subjected to the rubbing treatment are arranged to face each other so that the rubbing directions are antiparallel to each other, and a gap of 50 μm is provided between the two substrates. Next, the periphery of the two substrates is bonded with a sealant, and liquid crystal ZLI-4792 (manufactured by Merck) is injected into the gap between the two substrates and sealed to form a liquid crystal cell.

[Liquid crystal orientation evaluation]
The liquid crystal display element formed by the above-described method was observed with an optical microscope.

[Measurement of light transmittance]
After applying a liquid crystal aligning agent having a solid content concentration of 15% on a glass substrate by spin coating, the glass layer is temporarily dried at 80 ° C. and then finally dried at 200 ° C. to form a resin layer with a thickness of about 1 μm. A sample for rate evaluation was prepared. Using a UV-visible spectrophotometer, the light transmittance at 400 nm was measured. The transmittance of the resin layer was 80% or more, and less than 80% was evaluated as x.

  From Table 1, Examples 1 to 8 have good rubbing resistance, liquid crystal molecule orientation and spectral transmittance, whereas Comparative Example 1 has good liquid crystal molecule orientation and spectral transmittance. Although the rubbing resistance is inferior and Comparative Examples 2 and 3 have good rubbing resistance, the orientation and spectral transmittance of liquid crystal molecules are inferior.

  The difference between Example 1 and Comparative Example 1 is whether or not cyclobutanetetracarboxylic dianhydride (CBDA) is added. By adding CBDA, rubbing resistance can be improved. Moreover, when Example 8 and Comparative Example 3 are compared, the polyimide resin is the same, but in Example 8, it is a difference whether or not an alicyclic epoxy compound was used, and by using an alicyclic epoxy compound, It can be seen that the orientation and spectral transmittance of the liquid crystal molecules can be improved. On the other hand, since Comparative Example 3 uses a glycidyl-based additive, the compatibility with polyimide containing a large amount of alicyclic structure is poor, and the orientation of liquid crystal molecules is poor.

  Next, Examples 9 to 11 and Comparative Examples 4 to 7 when the polyimide resin composition of the present invention is used for an insulated wire will be described.

Example 9;
100 g of the polyimide powder obtained in Example 1 and 20 g of 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate were mixed, and an extruder manufactured by Parker Corporation (Brabender Plasticcoder) PL2000 type), using a tin-plated annealed copper wire with a diameter of 1.3 mm as a conductor, an insulated wire was produced at a cable insulator thickness of 0.5 mm and an extrusion temperature of 300 ° C.

Example 10;
100 g of the polyimide powder obtained in Example 2 and 20 g of vinylcyclohexene monooxide-1,2-epoxy-4-vinylcyclohexane were mixed, and an insulated wire was produced in the same manner as in Example 9.

Example 11;
100 g of the polyimide powder obtained in Example 3 and 20 g of 3,4-epoxycyclohexylmethyl acrylate were mixed, and an insulated wire was produced in the same manner as in Example 9.

Comparative Example 4;
An insulated wire was produced using only a polymer having an alicyclic structure and no alicyclic epoxy compound.

  Specifically, 100 g of the polyimide powder obtained in Example 1 was transferred to a cable of a tin-plated annealed copper wire with a diameter of 1.3 mm using a extruder manufactured by Parker Corporation (Brabender / Plasticcoder PL2000 type). An insulated wire was produced with an insulator thickness of 0.5 mm and an extrusion temperature of 300 ° C.

Comparative Example 5;
An insulated wire was made of a polymer having no alicyclic structure and an alicyclic epoxy compound.

  Specifically, in the same apparatus as in Example 1, 12.41 g of 4,4′-oxydiphthalic dianhydride, 6.09 g of 3,5-diaminobenzoic acid, 0.46 g of γ-caprolactone, 0.63 g of pyridine, NMP68.24g and toluene 20g were added, and it stirred for 10 minutes in nitrogen atmosphere at room temperature, Then, it heated up at 180 degreeC and stirred for about 10 hours, and obtained the reaction liquid. The water generated during the reaction was distilled out of the reaction system by azeotropy with toluene. Next, the resulting varnish was poured into methanol, and the resulting precipitate was pulverized, filtered, washed and dried under reduced pressure to obtain a polyimide powder. The obtained polyimide resin was diluted with NMP to a solid content concentration of 3% by weight, and 0.59 g of 3,4-epoxycyclohexenylmethyl-3, '4'-epoxycyclohexenecarboxylate was added, but the solubility was low. , It has become cloudy. Moreover, when extrusion molding was carried out in the same manner as in Comparative Example 4, the materials were not mixed uniformly, so that molding failed and evaluation was impossible.

Comparative Example 6;
An insulated wire was prepared from a polymer having an alicyclic structure and a non-alicyclic epoxy compound.

  Specifically, the polyimide resin obtained in Example 1 was diluted with NMP to a solid concentration of 3% by weight, and 1.18 g of bisphenol A type epoxy resin was further added, but the solubility was low and the solution became cloudy. . Moreover, when extrusion molding was carried out in the same manner as in Comparative Example 4, the materials were not mixed uniformly, so that molding failed and evaluation was impossible.

Comparative Example 7;
An insulated wire was made of a polymer having an alicyclic structure and a non-alicyclic aromatic epoxy compound.

Specifically, 100 g of the polyimide resin obtained in Comparative Example 3 and 20 g of N, N, N ′, N′-tetraglycidyl-m-xylylenediamine were mixed, and an insulated wire was obtained by the same method as in Comparative Example 4. However, the moldability was poor and the surface of the insulating material became uneven, and evaluation was impossible.
[Abrasion evaluation of wire insulation]
In the test, the tape type abrasion tester shown in FIG. 1 was used.

  The insulated wire 3 of the test sample obtained by the insulated wire manufacturing method is fixed to the gripping tools 21 and 21 of the testing machine 20 so as to be in contact with the platen 22 at the center of the gripping tools 21 and 21. The insulated wire 3 is put on a 450 g weight 1 through a holding jig 9 and brought into contact with the tape 2 (sandpaper, number 150) on the platen 22.

  Thereafter, the tape 2 is moved in the longitudinal direction, the insulator of the insulated wire 3 is polished, and the moving distance of the tape 2 until the conductive wire 4 of the insulated wire 3 is exposed (conduction is detected by a test machine) is compared. .

  The method for detecting continuity by the tester is as follows.

  The surface of the tape 2 that is in contact with the insulated wire 3 is a sandpaper surface, and a silver paste layer is thinly coated on the surface thereof to have conductivity.

  The tape 2 is moved in the longitudinal direction of the insulated wire 3 shown in FIG. 1, the tape 2 is supported by the platen 22, and the weight 1 is placed on the insulated wire 3. The surface of the insulated wire 3 is shaved by polishing the covering portion, and when the tape 2 reaches the conductive wire 4, the conductive wire 4, the tape 2, and the metal tape feed roller 5 are electrically connected.

  By observing the continuity between the lead wire 6 electrically connected to the terminal 8 of the lead wire 4 and the lead wire 7 electrically connected to the roller 5, the tape feeding function is stopped in this apparatus. .

  The results of this continuity test are shown in Table 2.

  In Table 2, those having a tape moving distance of less than 5 m were evaluated as x and those having 5 m or more as ◯.

  From Table 2, all of Examples 9 to 11 have good wear characteristics, and Comparative Example 4 has poor wear characteristics. Moreover, in Comparative Examples 5-7, since moldability was bad, test evaluation was not performed.

It is a side view of the tape abrasion tester of the insulated wire in this invention.

Explanation of symbols

2 Tape 3 Insulated wire 20 Tape wear tester

Claims (10)

  It is at least one polymer selected from polyamic acid or polyimide which is a reaction product of tetracarboxylic dianhydride and a diamine compound, and the polymer is composed of a polymer having an alicyclic structure and an alicyclic epoxy compound. A polyimide resin composition characterized by the above.   The polyimide resin composition according to claim 1, wherein the alicyclic structure of the alicyclic epoxy compound is a cyclohexane ring structure. The polyimide resin composition according to claim 1, wherein the alicyclic epoxy compound is a compound represented by Chemical Formula 1.

(In the formula, R ₁ represents a monovalent organic group, and R ₂ represents hydrogen or an organic group.)   The polyimide resin composition according to any one of claims 1 to 3, wherein the polyimide resin composition contains at least one acid anhydride or amine compound having an alicyclic structure.   An insulated wire obtained by applying the polyimide resin composition according to claim 1 to an insulating material of an insulated wire.   A liquid crystal aligning agent comprising at least one polymer selected from polyamic acid, which is a reaction product of tetracarboxylic dianhydride and a diamine compound, and a polyimide and an alicyclic epoxy compound as constituent components.   The liquid crystal aligning agent according to claim 7, wherein the polymer has an alicyclic structure.   The liquid crystal aligning agent according to claim 6 or 7, wherein the alicyclic structure of the alicyclic epoxy compound is a cyclohexane ring structure. The alicyclic epoxy compound is

(In the formula, R ₁ represents a monovalent organic group, and R ₂ represents hydrogen or an organic group.)
The liquid crystal aligning agent in any one of Claims 6-8 characterized by the above-mentioned. The liquid crystal aligning agent according to any one of claims 6 to 9, wherein the liquid crystal aligning agent contains at least one acid anhydride having an alicyclic structure or an amine compound having an alicyclic structure.

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