JP2846902B2 - Coating solution for electronic materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a coating liquid for an electronic material including a polyamide film having excellent solubility in a solvent and a film having excellent light transmittance obtained by curing the same. The present invention relates to an electronic material such as a color filter substrate, a protective film thereof, a liquid crystal alignment film, various protective films for semiconductors or a planarizing film.

[Conventional technology]

2. Description of the Related Art Wholly aromatic polyimide resins are widely used as protective materials and insulating materials in the field of electronic devices, or as adhesives, films or structural materials, mainly from the viewpoint of heat resistance.
However, when it is used as a film, it has a low transmittance of light in a low wavelength region (for example, a wavelength of about 400 nm) among visible rays, and is colored light yellow to brown.

However, such coloring is difficult to apply in a field requiring light transmittance (for example, a color filter base material or a protective film thereof), and therefore, attempts have been conventionally made to improve this aspect.

For example, improvements have been proposed in JP-A-60-6726, JP-A-61-141731, JP-A-61-141732 and JP-A-63-170420.

[Problems to be solved by the invention]

As a method for improving the transparency of a polyimide resin, a method in which an acid anhydride as a raw material is converted into an alicyclic compound (for example, see
No.-6726), those in which a diamine as a raw material is used as a sulfone group-containing compound (eg, JP-A-61-141731 and JP-A-61-141731).
Japanese Patent Application Laid-Open No. 61-141732 or a method in which an acid anhydride as a raw material is used as a fluorine-containing compound (eg, Japanese Patent Application Laid-Open No. 63-170420) have been proposed.

However, the polyimide resin obtained by these methods has a transmittance of 95% for light having a wavelength of 400 nm when the film thickness is about 1 to 2 μm.
However, for example, the film thickness becomes thicker,
With a film of 10 μm or more, it was difficult to obtain a film having a transmittance exceeding 95%.

In addition, all cycloaliphatic polyimides obtained from cyclobutanetetracarboxylic dianhydride obtained by dimerization of maleic anhydride alone, which is an inexpensive raw material, are good in terms of light transmittance, but the precursor is basic. It is only soluble in solvents, so if it is used, for example, for the purpose of a color filter protective film, the dye in the color filter is extracted at the time of application, except for those that have been specially treated, and the protective film is colored, impairing the function of the color filter. There is a fact that.

An object of the present invention is to obtain a coating liquid comprising a polyimide precursor having excellent solubility in a solvent and a solvent, and to provide a polyimide film having excellent visible light transmittance by curing the coating liquid.

[Means for solving the problem]

A first aspect of the present invention is a polyimide precursor comprising an amic acid repeating unit represented by the following general formula (I) and having a logarithmic viscosity number of 0.1 to 5 dl / g, 2-methoxyethanol, 2-ethoxyethanol, An electronic material comprising at least one non-polar solvent selected from the group consisting of butoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, cyclopentanone, cyclohexanone, cresol, γ-butyrolactone, and tetrahydrofuran. Coating solution.

[In the formula (I), R is a group represented by the following formula (II) or (III), and R ² is 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane , 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3 '
At least one alicyclic diamine residue selected from the group consisting of dimethyldicyclohexyl and isophoronediamine.

Here, R ¹ is independently a methyl group or an ethyl group, and p is an integer of 1 ≦ p ≦ 3.

Here, q is an integer of 2 ≦ q ≦ 10. In addition, instead of R ^{2 in} the above formula (I), R ³ is 4,4′-diaminodicyclohexylmethane, 2,2-bis [4- (4- (aminophenoxy) phenyl] hexafluoropropane, 3,3 ′ -A coating liquid for an electronic material in which at least one alicyclic diamine residue selected from the group consisting of diaminodiphenyl sulfone is used.

Further, as R of (I), 1-methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo (4.2.0) octane
This is a coating liquid for electronic materials in which any anhydride residue of 1,6,7,8-tetracarboxylic dianhydride is used.

The coating liquid for an electronic material according to any one of the above, wherein ethyl carbitol is used as a solvent.

Examples of the alicyclic diamine include the following compounds. That is, 1,4-diaminocyclohexane, 1,3-
Diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexyl and isophoronediamine.

Examples of the carbon dry aromatic diamines include the following compounds.

o-, m- and p-phenylenediamine, diaminotoluenes (eg, 2,4-diaminotoluene), 1,4-diamino-2-methoxybenzene, 2,5-diaminoxylenes, 1,3-diamino- 4-chlorobenzene, 1,4-diamino-2,5-dichlorobenzene, 1,4-diamino-2-bromobenzene, 1,3-diamino-4-isopropylbenzene, N, N'-diphenyl-1, 4-phenylenediamine,
4,4'-diaminodiphenyl-2,2-propane, 4,4'-
Diaminodiphenylmethane, 2,2'-diaminostilbene, 4,4'-diaminostilbene, 4,4'-diaminodiphenyl-ether, 4,4'-diaminodiphenyl-thioether, 4,4'-diaminodiphenylsulfone, 3, 3 ′
-Diaminodiphenyl sulfone, 4,4'-diaminobenzoic acid phenyl ester, 2,2'-diaminobenzophenone, 4,4'-diaminobenzophenone, 4,4'-diaminobenzyl, 4- (4'-aminophenylcarbamoyl)
-Aniline, bis (4-aminophenyl) -phosphine oxide, bis (4-aminophenyl) -methyl-phosphine oxide, bis (3-aminophenyl) -methylsulfin oxide, bis (4-aminophenyl)- Phenylphosphine oxide, bis (4-aminophenyl) -cyclohexylphosphine oxide, N, N-bis (4-aminophenyl) -N-phenylamine, N, N-
Bis (4-aminophenyl) -N-methylamine, 4,
4'-diaminodiphenylurea, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoanthraquinone, diaminofluoranthene, bis (4-aminophenyl) -diethylsilane, bis (4-aminophenyl ) -Dimethylsilane, bis (4-aminophenyl)-
Tetramethyldisiloxane, 3,4'-diaminodiphenyl ether, benzidine, 2,2'-dimethylbenzidine, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) ) Phenyl] sulfone, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (4-aminophenoxy) Benzene, 1,3-bis (4-
Aminophenoxy) benzene.

Examples of the hetero-dry diamines include the following compounds.

2,6-diaminopyridine, 2,4-diaminopyrimidine,
2,4-diamino-s-triazine, 2,7-diamino-dibenzofuran, 2,7-diaminocarbazole, 3,7-diaminophenothiazine, 2,5-diamino-1,3,4-thiadiazole, 2,4- Diamino-6-phenyl-s-triazine.

Further, examples of the aliphatic diamine include the following compounds.

Dimethylamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, heptamethinediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, 2,2-dimethylpropylenediamine, 2,5-dimethylhexamethylenediamine, 2 , 5-dimethylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 3-methoxyheptamethylenediamine, 5
-Methylnonamethylenediamine, 2,11-diaminododecane, 1,12-diaminooctadecane, 1,2-bis (3-aminopropoxy) -ethane, N, N'-dimethyl-ethylenediamine, N, N'-diethyl- 1,3-diaminopropane, N, N'-dimethyl-1,6-diaminohexane, a diamine represented by the formula: H ₂ N (CH ₂ ) ₃ O (CH ₂ ) ₂ O (CH ₂ ) ₃ NH ₂ .

The following compounds can be mentioned as siloxane-based diamines.

Preferred solvents (hereinafter, sometimes referred to as “reaction solvents”) for reacting the above-mentioned starting compounds in a solvent include 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, diethylene glycol monomethyl ether, and diethylene glycol mono. Non-polar solvents such as ethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, cyclopentanone, cyclohexanone, cresol, γ-butyrolactone, and tetrahydrofuran can be suitably used. Further, N-methyl-2-pyrrolidone, N,
N-dimethylacetamide, N, N'-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylphosphoramide, methylformamide, N- Basic solvents such as acetyl-2-pyrrolidone, N, N-dimethylmethoxyacetamide, N-acetyl-2-pyrrolidone, N-methyl-ε-caprolactam and the like can also be used.

As described above, a polyimide precursor containing the repeating unit of the formula (I) can be obtained by a method known per se.
It is possible to constitute the polyimide precursor coating solution of the present invention only with a polyimide precursor composed of only this repeating unit (I) among all amic acid repeating units.

However, among the raw materials, part of the acid dianhydride represented by the formula (VI) is replaced with an aromatic dianhydride, an aliphatic dianhydride,
It can be replaced by cyclobutanetetracarboxylic dianhydride or the like. However, a polyimide film obtained from a raw material having a large ratio of aromatic compounds has a reduced light transmittance, and if the ratio of aliphatic compounds is large, the heat resistance of the obtained polyimide film is reduced, and cyclobutanetetracarboxylic dianhydride is obtained. When the ratio of the products is large, the obtained polyimide precursor becomes difficult to be dissolved in a solvent other than the basic solvent, and neither is preferable.

Accordingly, of all the amic acid repeating units in the polyimide precursor and all the imide repeating units in the polyimide, the repeating units (I) and (V) account for at least 60 mol%, preferably 80 mol%.
The above is good.

It is particularly preferred that R ² is an alicyclic group.

Specific examples of the aromatic dianhydride and the aliphatic dianhydride are shown below.

Pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (3,4-di Carboxyphenyl) -ether dianhydride, bis (3,4-dicarboxyphenyl) -sulfone dianhydride, bis (3,4-
Dicarboxyphenyl) -sulfide dianhydride, 2,2-
Bis (3,4-dicarboxyphenyl) -hexafluoropropane dianhydride, 1,2,3,4-tetracarboxybutane dianhydride.

In order to improve the adhesion to the substrate, aminosilane of 10 mol% or less of the whole raw material can be added. These can react with terminal anhydride groups to form polymer ends. Specific examples are shown below.

Next, the reaction method will be described. An acid dianhydride containing 60 mol% or more of the tetracarboxylic dianhydride represented by the formula (IV), and the diamine represented by the formula (VII) and 0 to 10 mol% of the aminosilane in all the raw material compounds, The reaction is performed in a reaction solvent.

In this case, the mixing ratio of the raw materials is determined so that the amount of the repeating unit represented by the formula (I) in the synthesized polyimide precursor is 60 mol% or more.

In addition, the total amount of the acid dianhydride and the total amount of the diamine are made to be approximately equimolar, but either one may be in excess within 10 mol%.

The reaction solvent is preferably used in an amount of 50% by weight or more based on the total amount of the reaction solvent and the added raw materials. If the amount of solvent is less than this, stirring may be difficult, which is not preferable. The reaction may be any method as long as it is a method of synthesizing a polyimide precursor, which is usually performed, but the raw materials are supplied to the reactor in a lump or in a batch in a solvent, and at a temperature of 0 to 100 ° C. for several hours to several tens of hours. It is common to do. Thus, a solution containing the polyimide precursor of the present invention is obtained.

Apply this solution to the substrate and heat to 100-400 ° C or
Alternatively, an acid anhydride such as acetic anhydride and / or a known imidization accelerator such as pyridine or isoquinoline are added thereto.
By imidizing the precursor and evaporating the solvent at a relatively low temperature of 10 to 100 ° C., the cured polyimide film of the present invention can be obtained.

The average molecular weight of the polyimide precursor of the present invention is preferably such that the logarithmic viscosity number measured under the above-mentioned constant conditions is in the range of 0.1 to 5 dl / g.

In the present invention, the logarithmic viscosity number is as defined by the measurement conditions. More specifically, the logarithmic viscosity number is represented by the following equation.

(Here, η is a value measured using a Ubbelohde viscometer at a concentration of 30 g / dl in a solvent at a temperature of 30 ± 0.01 ° C., and η ₀ is a value obtained by using an Ubbelohde viscometer at the same temperature. When the logarithmic viscosity number is less than 0.1, the resulting cured polyimide film is often inferior in mechanical strength, which is not preferable, and the synthesis of a cured polyimide film exceeding 5 is difficult. is there.

Next, a method of using the precursor solution and the polyimide film used in the present invention will be described. Since the precursor in the present invention is used in the state of a solution dissolved in a solvent, it is preferable to use the reaction solution as it is or by concentrating it, or diluting it by adding a solvent. As the diluting solvent, the same solvent as the reaction solvent can be used.

When the cured polyimide film used in the present invention is formed from the precursor solution used in the present invention, any known method may be used.

For example, after applying a precursor solution on a substrate such as a glass plate, a copper plate, an aluminum plate or a silicon wafer, 50
By baking at a temperature of about 400 ° C., a transparent cured polyimide film used in the present invention can be obtained. In this case, the coating method may be any method, but usually a spin coating method,
The method is selected from a printing method, a dipping method, a roll coater method, and the like.

The cured polyimide film of the present invention has good visible light transmittance, that is, it is suitably used as a color filter protective film because of its high transparency, and an organic pigment or dye is dispersed in the polyimide precursor solution of the present invention. Alternatively, a colored paste for a color filter can be easily obtained by dissolving. The color paste can be obtained by applying this colored paste to a substrate by any of the above-mentioned application methods and baking the applied paste. As the pigment, for example, red quinacridone red, green phthalocyanine green, blue phthalocyanine blue and the like can be used. Addition ratio of pigment or dye is 10 ~ of polymer
It is 200% by weight, preferably 20 to 100% by weight. The color filter substrate of the present invention and the protective film thereof can be used for a color liquid crystal display device or an imaging device. The cured film obtained from the polyimide precursor solution in the present invention has excellent heat resistance, mechanical properties, and electrical properties, and is also suitable for various protective films for semiconductors, flattening films, alignment films for liquid crystals, and the like. Can be used for

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples, Reference Examples, and Comparative Examples. However, it is needless to say that the present invention is not limited to these Examples. The transparency of the polyimide was measured using a Shimadzu UV-210A spectrophotometer, which was applied to quartz glass and baked.

Example 1 A 1-liter separable flask was equipped with a stirrer, a thermometer, a condenser, and a nitrogen purge device. After the inside of the flask was replaced with nitrogen, dehydrated and purified ethyl carbitol.
500 g were added, followed by 57.40 g (271 mmol) of 4,4'-diaminodicyclohexylmethane and 6.60 g (31.0 mmol) of p-aminophenyltrimethoxysilane.
After stirring to make a homogeneous solution, 1-methyl-1,2,3,4
-61.00 g of cyclobutanetetracarboxylic dianhydride (290
(Mmol) and stirring was continued at room temperature to 50 ° C. for 8 hours to obtain a pale yellow viscous liquid. The logarithmic viscosity number of this product in ethyl carbitol was 1.10 dl / g. This solution was spin-coated on quartz glass and baked in a nitrogen atmosphere at 80 ° C for 30 minutes and then at 250 ° C for 60 minutes, and the transmittance was measured using a spectrophotometer. The transmittance was 98.0% at a wavelength of 10 μm and a wavelength of 400 nm.

Example 2 In a 1 liter separable flask, 39.03 g (184 mmol) of 4,4'-diaminodicyclohexylmethane, 2,2-bis [4- (4-
Aminophenoxy) phenyl] hexafluoropropane 2
After dissolving 5.47 g (49.1 mmol) and 5.44 g (24.6 mmol) of 3-aminopropyltriethoxysilane in 500 g of dehydrated and purified ethyl carbitol, 1,3-dimethyl-1,2,3,4- 55.06 g (246 mmol) of cyclobutanetetracarboxylic dianhydride was added, and the mixture was stirred at room temperature to 50 ° C. for 10 hours to give a pale yellow viscous liquid. The logarithmic viscosity number of this product in ethyl carbitol is
It was 1.50 dl / g. This liquid was spin-coated on quartz glass and baked in a nitrogen atmosphere at 80 ° C. for 30 minutes and then at 250 ° C. for 60 minutes, and the transmittance was measured using a spectrophotometer. The transmittance was 97.1% at a film thickness of 10 μm and a wavelength of 400 nm.

Example 3 In a 1-liter separable flask, 52.48 g (248 mmol) of 4,4'-diaminodicyclohexylmethane and 2,2-bis [4-
(4-Aminophenoxy) phenyl] hexafluoropropane (6.76 g, 13 mmol) was dissolved in dehydrated and purified ethyl carbitol (500 g), and then dissolved in 1,2,3,4-tetramethyl-1,2,3,4 '-Cyclobutanetetracarboxylic dianhydride (65.76 g, 261 mmol) was added, and the mixture was stirred at a temperature from room temperature to 50 ° C for 13 hours to give a pale yellow viscous liquid. The logarithmic viscosity number of this product in ethyl carbitol is 0.
It was 89 dl / g. This liquid was spin-coated on quartz glass and baked in a nitrogen atmosphere at 80 ° C. for 30 minutes and then at 250 ° C. for 60 minutes, and the transmittance was measured using a spectrophotometer. 9 at a film thickness of 10 μm and a wavelength of 400 nm
The transmittance was 6.2%.

Example 4 In a 1-liter separable flask, 43.34 g (205 mmol) of 4,4'-diaminodicyclohexylmethane and 6.35 g (25.6 mmol) of 3,3'-diaminodiphenylsulfone in a 1-liter separable flask in the same manner as in Example 1. , And 11.32 g (51.1 mmol) of 3-aminopropyltriethoxysilane
After dissolving in 500 g of dehydrated and purified ethyl carbitol, 93.98 g (256 mmol) of bicyclo [4.2.0] octane-1,6,7,8-tetracarboxylic dianhydride was added, and the mixture was heated from room temperature to 50 ° C. After stirring at the temperature for 15 hours, a pale yellow viscous liquid was obtained. The logarithmic viscosity number of this product in NMP is 0.68d
l / g. This solution was spin-coated on quartz glass and baked in a nitrogen atmosphere at 80 ° C for 30 minutes and then at 250 ° C for 60 minutes, and the transmittance was measured using a spectrophotometer. 96 at 10 μm, wavelength 400 nm.
The transmittance was 9%.

Example 5 In a 1 liter separable flask, 55.95 g of isophoronediamine was prepared in the same manner as in Example 1.
(329 mmol) was dehydrated and purified with ethyl carbitol 5
After dissolving in 100 g, 69.05 g (329 mmol) of 1-methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride
Was added and stirred at room temperature to 50 ° C. for 13 hours to give a pale yellow viscous liquid. The logarithmic viscosity number of this product in ethyl carbitol was 0.91 dl / g. This solution is spin-coated on quartz glass and placed in a nitrogen atmosphere at 80 ° C.
When the transmittance was measured with a spectrophotometer, the transmittance was 96.2% at a film thickness of 10 μm and a wavelength of 400 nm.

Example 6 In a 1-liter separable flask, 48.57 g (229 mmol) of 4,4'-diaminodicyclohexylmethane and 3.00 g (12.1 mmol) of 3,3'-diaminodiphenylsulfone were prepared in the same apparatus and method as in Example 1. Was dissolved in 500 g of dehydrated and purified ethyl carbitol, and 73.74 g (241 mmol) of tricyclo [6.4.0.0 ^2,7 ] dodecane-1,8,2,7-tetracarboxylic dianhydride was added. Room temperature to 50
After stirring at a temperature of ° C. for 17 hours, a pale yellow viscous liquid was obtained. The logarithmic viscosity number of this product in ethyl carbitol was 0.54 dl / g. This solution is spin-coated on quartz glass, and then at 80 ° C for 30 minutes in a nitrogen atmosphere, and then at 250 ° C for 6 minutes.
When the transmittance of the product fired for 0 minutes was measured by a spectrophotometer, the transmittance was 96.6% at a film thickness of 10 μm and a wavelength of 400 nm.

Comparative Example 1 In a 1-liter separable flask, 64.91 g (306 mmol) of 4,4'-diaminodicyclohexylmethane was dissolved in 500 g of dehydrated and purified ethyl carbitol in the same apparatus and method as in Example 1. 60,09 g (309 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride were added and stirred at room temperature to 50 ° C.
A white mass formed 30 minutes after the start. Stirring was continued for another 10 hours, but the mass was not dissolved and the reaction was stopped.

Comparative Example 2 In a 1-liter separable flask, 77.09 g of 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane (149) was prepared in the same apparatus and method as in Example 1.
Was dissolved in 500 g of dehydrated and purified ethyl carbitol, 47.91 g (149 mmol) of benzophenonetetracarboxylic dianhydride was added, and the mixture was stirred at room temperature to 50 ° C. for 9 hours. It became a good liquid. The logarithmic viscosity number of this product in ethyl carbitol is 1.
It was 73 dl / g. This solution was spin-coated on quartz glass and baked in a nitrogen atmosphere at 80 ° C for 30 minutes and then at 250 ° C for 60 minutes, and the transmittance was measured using a spectrophotometer. 28 at 10 μm, 400 nm wavelength.
The transmittance was 5%.

Comparative Example 3 In a 1-liter separable flask, 62.17 g (293 mmol) of 4,4'-diaminodicyclohexylmethane was dissolved in 500 g of dehydrated and purified ethyl carbitol in the same apparatus and method as in Example 1. After that, 1-methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 30.
83 g (147 mmol) and pyromellitic dianhydride 32.0
0 g (147 mmol) are added at room temperature to 30 ° C.
After stirring for an hour, a brown viscous liquid was obtained. The logarithmic viscosity number of this product was 1.19 dl / g. This solution was spin-coated on quartz glass and baked in a nitrogen atmosphere at 80 ° C for 30 minutes and then at 250 ° C for 60 minutes, and the transmittance was measured using a spectrophotometer. The transmittance was 50.2% at a wavelength of 10 μm and a wavelength of 400 nm.

Example 7 To 120 g of the varnish synthesized in Example 1, 25 g of powdery phthalocyanine blue was added and kneaded with an automatic mortar to prepare a varnish for a blue colored color filter.
After applying this varnish on a glass plate by a spinner, under nitrogen atmosphere 50 ° C 30 minutes, 150 ° C 30 minutes and 250 ° C
By firing for 1 hour, a colored color filter was formed on the glass plate. Visually, the pigment phthalone anine blue was uniformly dispersed, and a clear blue color filter was obtained. Further, for the purpose of forming a protective film on the color filter, the varnish obtained in Example 1 containing no pigment was similarly applied and baked.
Thus, a protective film having a transparent and smooth surface was formed on the color filter. A 2 mm square section was peeled off using a cellophane tape. According to a test of ruggedness, the adhesiveness between the glass plate and the color filter and between the color filter and the protective film were all good.

Example 8 The varnish synthesized in Example 1 was diluted with ethyl carbitol to prepare a solution having a solid content of 8%, which was used as a coating solution. This is spin-coated on a glass substrate with a transparent electrode,
By firing at 220 ° C. for 1 hour, a film having a thickness of 800 ° was formed. After rubbing this film, a liquid crystal (LIXON (registered trademark) 6300, manufactured by Chisso Corporation) was injected and assembled into a TN cell. The liquid crystal alignment of the liquid crystal cell thus prepared was good.

Example 9 A film of about 1 μm of an acrylic color filter material (CFP-7215NB manufactured by Chisso Corporation) was formed on a glass plate, and the film was dyed with a red dye (21P manufactured by Nippon Kayaku Co., Ltd.). The varnish synthesized in (1) was applied by spin coating, and heated at 200 ° C. for 1 hour to form a protective film having a thickness of about 1.5 μ on the color filter. When this film was observed and it was examined whether or not the dye had transferred to the protective film, the film was transparent and no transfer of the dye was observed.

Comparative Example 4 Using the same apparatus and method as in Example 1, 59.10 g (281 mmol) of 4,4'-diaminodicyclohexylmethane and p
6.85 g (32.1 mmol) of aminophenyltrimethoxysilane are added to 500 g of N-methyl-2-pyrrolidone, and to this solution 59.02 g (301 mmol) of cyclobutanetetracarboxylic dianhydride are added, and 50 ° C. The mixture was stirred for 10 hours to obtain a pale yellow viscous solution. The logarithmic viscosity number of the obtained polyamic acid in N-methyl-2-pyrrolidone was 0.85 dl / g. This varnish was applied on a color filter prepared in the same manner as in Example 9 by spin coating, and heated at 200 ° C. for 1 hour to obtain a thickness of about 1.5
μ of the protective film was formed. Observing this film,
Transfer of a red dye was observed, and the color was light red.

〔The invention's effect〕

Since the coating liquid for electronic materials of the present invention contains a polyamic acid having excellent solubility in a solvent, the choice of the solvent is widened. Therefore, a solvent can be selected with little damage to the substrate, and the practical effect is large. Further, the cured polyimide film obtained from the coating solution is excellent in transparency and thus is suitable as a color filter substrate and a protective film thereof, and is also preferable as various protective films for semiconductors or a planarizing film. It also has good characteristics as a liquid crystal alignment film.

Claims (4)

(57) [Claims] 1. A polyimide precursor comprising an amic acid repeating unit represented by the following general formula (I) and having a logarithmic viscosity number of 0.1 to 5 dl / g, 2-methoxyethanol, 2-ethoxyethanol and 2-butoxy Coating for electronic materials comprising at least one non-polar solvent selected from the group consisting of ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, cyclopentanone, cyclohexanone, cresol, γ-butyrolactone, and tetrahydrofuran. liquid. [In the formula (I), R is a group represented by the following formula (II) or (III), and R ² is 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane , 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3 '
At least one alicyclic diamine residue selected from the group consisting of dimethyldicyclohexyl and isophoronediamine. Here, R ¹ is independently a methyl group or an ethyl group, and p is an integer of 1 ≦ p ≦ 3. Here, q is an integer of 2 ≦ q ≦ 10. ] 2. A polyimide precursor comprising an amic acid repeating unit represented by the following general formula (I) and having a logarithmic viscosity number of 0.1 to 5 dl / g, 2-methoxyethanol, 2-ethoxyethanol and 2-butoxy Coating for electronic materials comprising at least one non-polar solvent selected from the group consisting of ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, cyclopentanone, cyclohexanone, cresol, γ-butyrolactone, and tetrahydrofuran. liquid. [In the formula (I), R is a group represented by the following formula (II) or (III), and R ² is 4,4'-diaminodicyclohexylmethane, 2,2-bis [4- (4- (amino Phenoxy) phenyl] at least one alicyclic diamine residue selected from the group consisting of hexafluoropropane and 3,3'-diaminodiphenylsulfone. Here, R ¹ is independently a methyl group or an ethyl group, and p is an integer of 1 ≦ p ≦ 3. Here, q is an integer of 2 ≦ q ≦ 10. ] 3. The method according to claim 1, wherein R in (I) is 1-
Methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo [4.2.0] octane-1, 6,
The coating liquid for an electronic material according to claim 1, which is any anhydride residue of 7,8-tetracarboxylic dianhydride. 4. The method according to claim 1, wherein the solvent is ethyl carbitol.
4. The coating material for an electronic material according to any one of claims 1 to 3.