JP2637391B2 - Polyimide resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyimide resin having good heat resistance and having a higher adhesiveness than conventional polyimide resins.

[0002]

2. Description of the Related Art Polyimide resins are widely known as resins having excellent heat resistance, electrical insulation and mechanical properties.
For this reason, in recent years, polyimide resins have been used in the field of the semiconductor industry, and demands for new performance improvements have been increasing. For example, when a polyimide resin is used as an alignment film of a liquid crystal display element, the polyimide resin is required to have high light transmittance. In addition, when a polyimide resin is used as an interlayer insulating film of an IC or the like, it is required to have high adhesion to a substrate.

However, when a conventional polyimide resin is produced by subjecting a polyamic acid, which is a precursor thereof, to a cyclization reaction by heat treatment, it is colored yellow-brown, and thus has a problem in that light transmittance is reduced.

In addition, when a conventional polyimide resin is adhered to a substrate, moisture invades from between the substrate and the polyimide resin due to poor adhesion to the substrate, resulting in a liquid crystal display element or an I.D.
C, there is a problem that the reliability of the LSI is greatly reduced.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a polyimide resin having low light transmittance and excellent adhesion to a substrate.

[0006]

The polyimide resin according to the present invention has a general formula

[0007]

Embedded image (However, Ar is

[0008]

Embedded image And represents a tetravalent organic group selected from

[0009]

Embedded image

[0010]

Embedded image

[0011]

Embedded image

[0012]

Embedded image Represents a divalent organic group selected from: m and n are 0.01 ≦ m
/(M+n)≦1.0.)
0.5 g / dl concentration N of polyamic acid as its precursor
The intrinsic viscosity of the -methyl-2-pyrrolidone solution at 30 ° C. is 0.15 dl / g or more.

Such a polyimide resin includes 2,2-bis (hydroxyaminophenyl) hexafluoropropane (II) and a diamino compound represented by the general formula H ₂ N—Z—NH ₂ .

[0014]

Embedded image With a tetracarboxylic dianhydride represented by the general formula

[0015]

Embedded image Can be obtained by synthesizing a polyamic acid having an intrinsic viscosity of 0.15 dl / g or more at 30 ° C. in a 0.5 g / dl concentration N-methyl-2-pyrrolidone solution, followed by a cyclization reaction.

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

In the present invention, examples of 2,2-bis (hydroxyaminophenyl) hexafluoropropane (II) include 2,2-bis (3-hydroxy-4-aminophenyl) hexafluoropropane and 2.2. -Bis (4-hydroxy-3-aminophenyl) hexafluoropropane, 2- (3-hydroxy-4-aminophenyl) -2- (4-hydroxy-3-aminophenyl) hexafluoropropane and the like can be mentioned. . One or more of these compounds are used.

In the present invention, the compound represented by the general formula (III)
Examples of the diamino compound represented by are m-phenylenediamine, p-phenylenediamine, 2,4-tolylenediamine, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,4 ′
-Diaminodiphenyl ether, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3
'-Diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 3,3
'-Diaminodiphenylketone, 4,4'-diaminodiphenylketone, 3,4'-diaminodiphenylketone, 2,2'-bis (p-aminophenyl) propane,
2,2'-bis (p-aminophenyl) hexafluoropropane, 1,3-bis (m-aminophenoxybenzene), 1,3-bis (p-aminophenoxybenzene), 1,4-bis (p- Aminophenoxybenzene), 4-methyl-2,4-bis (p-aminophenyl) -1-pentene, 4-methyl-2,4-bis (p-
Aminophenyl) -2-pentene, 1,4-bis (α,
α-dimethyl-p-aminobenzyl) benzene, imino-di-p-phenylenediamine, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 4-methyl-
2,4-bis (p-aminophenylpentane), 5 (or 6) -amino-1- (p-aminophenyl) -1,
3,3-trimethylindane, bis (p-aminophenyl) phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenylurea, 4,4'-
Bis (p-aminophenoxy) biphenyl, 2,2-bis [p- (p'-aminophenoxy) phenyl] propane, 2,2-bis [p- (m-aminophenoxy) phenyl] propane, 4,4 ' -Bis (p-aminophenoxy) benzophenone, 4,4'-bis (p-aminophenoxy) diphenylsulfone, 4,4'-bis (m-aminophenoxy) diphenylsulfone, 4,4'-bis [p- ( α, α-dimethyl-p′-aminobenzyl) phenoxy] benzophenone, 4,4′-bis [p-
(Α, α-dimethyl-p′-aminobenzyl) phenoxy] diphenylsulfone, bis (4-aminophenyl)
Examples include aromatic diamines such as dimethylsilane, bis (4-aminophenyl) tetramethyldisiloxane, and bis (m-aminophenyl) tetramethyldisiloxane. The hydrogen atom of the aromatic nucleus of these aromatic diamines is substituted with at least one substituent selected from the group consisting of a chlorine atom, a fluorine atom, a bromine atom, a methyl group, a methoxy group, a cyano group and a phenyl group. It may be a compound.

Examples of the diamino compound represented by the general formula (III) include, in addition to the above-mentioned aromatic diamines, dimethylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, and the like. Octamethylenediamine, nonamethylenediamine, decamethylenediamine,
1,2-bis (3′-aminopropoxy) ethane, 1,
4-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane,
1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylisopropane, 1,4-xylylenediamine, 2,6-diaminopyridine, 2,4-diamino-S-triazine, bis (γ-amino Propyl) tetramethyldisiloxane, 1,4-bis (γ-aminopropyldimethylsilyl) benzene, bis (4-aminobutyl) tetramethyldisiloxane, bis (γ-aminopropyl) tetraphenyldisiloxane, and the like. it can.

The diamino compound represented by the general formula (III) may not necessarily be used, and if necessary, one or more compounds selected from the above groups may be used.

In the present invention, examples of the tetracarboxylic dianhydride represented by the general formula (IV) include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride 2,3,3 ′, 4′-benzophenonetetracarboxylic dianhydride, 3,3 ′,
4,4′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride,
2,2-bis (3 ′, 4′-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride , Bis (3,4-dicarboxyphenyl) tetramethyldisiloxane dianhydride, 1-4-4-8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride And butanetetracarboxylic dianhydride. Note that these compounds are compounds in which a hydrogen atom is substituted with at least one substituent selected from the group consisting of a chlorine atom, a fluorine atom, a bromine atom, a methyl group, a methoxy group, a cyano group, and a phenyl group. You may.

As the compound represented by the general formula (IV), one or more compounds selected from the above groups are used.

The polyamic acid which is a precursor of the polyimide resin according to the present invention comprises 2,2-bis (hydroxyaminophenyl) hexafluoropropane (II) and, if necessary, a diamino compound (III) and tetracarboxylic acid dicarboxylic acid. It can be synthesized by a polycondensation reaction with an anhydride (IV) in an organic solvent. At this time, as the organic solvent used, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-
Examples thereof include pyrrolidone, N-methyl-ε-caprolactam, γ-butyrolactone, sulfolane, N, N, N ′, N′-tetramethylbromine, and hexamethylphosphamide.

In this reaction, the ratio between 2,2-bis (hydroxyaminophenyl) hexafluoropropane (II) and the diamino compound (III) is determined in accordance with the ratio of the repeating unit in the intended polyimide resin. . Also,
The ratio of the total amount of 2,2-bis (hydroxyaminophenyl) hexafluoropropane (II) and the diamino compound (III) to the ratio of tetracarboxylic dianhydride (IV) is
The molar ratio is 0.9 to 1.1: 1. The reaction conditions are a reaction temperature of -20 to 150 ° C. and a reaction time of 10 minutes to 20 hours.

Under the above conditions, a polyamic acid having m repeating units and n repeating units represented by the general formula (V) is produced. The generated polyamic acid may be used as a solution in the next step. Alternatively, the resulting polyamic acid solution may be poured into a poor solvent such as water, methanol, ethanol, acetone, or methyl ethyl ketone to precipitate a polymer, which may be washed and dried to recover a solid, which may be used in the next step.

In the present invention, the molecular weight of the polyamic acid to be synthesized is desirably such that a film capable of maintaining sufficient physical strength when coated on a substrate can be formed. From this viewpoint, it is desirable that the intrinsic viscosity at 30 ° C. of the polyamic acid / N-methyl-2-pyrrolidone solution having a concentration of 0.5 g / dl is 0.15 dl / g or more.

[0027]

[0028]

Further, by cyclizing the polyamic acid synthesized as described above, the polyimide resin of the present invention can be produced. This cyclization is performed by heat treatment or chemical treatment. In the heat treatment method, a polyamic acid solution is applied to an appropriate substrate such as glass or stainless steel, and the solvent is removed.The resulting polyamic acid film or film is heated to 100 to 400 ° C. to effect cyclization. A reaction is caused to produce a polyimide resin.
In the method by the chemical treatment, the polyamic acid solution is reacted in the presence of acetic anhydride, triethylamine, pyridine, sodium acetate, zinc acetate, manganese acetate, cobalt acetate or the like in a temperature range of -20 to 150 ° C. for 1 minute to 10 hours. This causes a cyclization reaction to produce a polyimide resin.

The polyimide resin thus produced has m repeating units and n repeating units represented by the general formula (I). In such a polyimide resin, since a hydroxyl group and a fluorine atom derived from 2,2-bis (hydroxyaminophenyl) hexafluoropropane are introduced into the polymer molecular skeleton, the adhesion to the substrate can be improved. Further, 2,2-bis (hydroxyaminophenyl) hexafluoropropane has a lower degree of coloring than other aromatic diamines and a lower degree of coloring even in a solution state, so that the obtained polyimide resin is also less than the conventional polyimide resin. Excellent light transmittance.
Further, it is considered that the presence of the fluorine atom also improves the light transmittance of the polyimide resin.

It is to be noted that the relation between the total number m and the number n of the respective repeating units is 0.01 ≦ m / (m + n) ≦ 1.0 because this value is
If it is less than 0.01, the number of hydroxyl groups and fluorine atoms introduced into the polymer skeleton is small, so that the adhesion to the substrate cannot be improved. More preferred m /
The range of the value of (m + n) is 0.1 to 0.9. this is,
If the value is less than 0.1, the adhesion to the substrate tends to decrease, while if it exceeds 0.9, the heat resistance of the obtained polyimide resin tends to decrease.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples. (Example 1) 14.71 parts by weight of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 50 parts by weight of N, N-dimethylacetamide were placed in a reaction flask equipped with a stirring rod, a thermometer, and a dropping funnel. Then, the mixture was sufficiently stirred and cooled to 0 ° C. The suspension was kept at 0 ° C. and 4.67 parts by weight of p-phenylenediamine, 0.75 parts by weight of bis (γ-aminopropyl) tetramethyldisiloxane and 2,2-bis (4-hydroxy-3-aminophenyl) hexa. Fluoropropane 1.
A solution of 13 parts by weight of N, N-dimethylacetamide in 70 parts by weight was gradually dropped from a dropping funnel. After completion of the dropwise addition, stirring was continued at 0 to 10 ° C for 6 hours to synthesize a polyamic acid.

A portion of the reaction solution was dropped into a poor solvent to precipitate a polyamic acid, which was washed and dried to recover the polyamic acid as a solid. The polyamic acid / N-methyl-2 having a concentration of 0.5 g / dl was recovered. Preparing the pyrrolidone solution,
When the intrinsic viscosity was measured at 30 ° C., 1.09 dl /
g.

Next, the above reaction solution was applied to a glass substrate at 2000 rpm using a spinner. p. m. The solution was uniformly coated at a rotation speed of, dried at 150 ° C. for 30 minutes to remove the solvent, and then peeled off from the substrate. This film was heated at 250 ° C. for 1.5 hours to cause a cyclization reaction, and a 1.4 μm-thick polyimide film was obtained. The elemental analysis value of this polyimide almost coincided with the calculated value as shown in Table 1 below. FIG. 1 shows an infrared absorption spectrum of this polyimide. As is clear from FIG. 1, there is strong characteristic absorption of the imide group at 1780 cm −1,
It can be seen that the obtained polymer is a polyimide resin.

[0035]

[Table 1] Then, in the same manner as above, a solution of polyamic acid is uniformly applied on a glass substrate to a thickness of 1 μm, and then heat-treated to form a polyimide film, and adhered according to the method specified in JIS K-5400, 6.14. An acidity test (peeling of the substrate) was performed. As a result, fifty base lines were formed, but did not peel at all.

The film thickness 1 formed in the same manner as described above
The light transmittance of the μm polyimide film measured at a wavelength of 450 nm was 85%. Example 2 In a reaction flask equipped with a stirring rod, a thermometer, and a dropping funnel, 8.727 parts by weight of pyromellitic dianhydride, 3,3 ′,
4,4'-benzophenonetetracarboxylic dianhydride 1
2.885 parts by weight and 70 parts by weight of N, N-dimethylacetamide were charged, sufficiently stirred, and cooled to 10 ° C. The suspension was kept at 10 ° C and 2,2-bis (4-hydroxy-
A solution of 29.301 parts by weight of (3-aminophenyl) hexafluoropropane in 70 parts by weight of N, N-dimethylacetamide was gradually dropped from a dropping funnel. After dropping,
Stirring was continued at 15 ° C. for 7 hours to synthesize a polyamic acid.

The intrinsic viscosity of the polyamic acid measured in the same manner as in Example 1 was 0.88 dl / g.

Next, the above reaction solution was put on a glass substrate at 2000 rpm using a spinner. p. m. The solvent was removed by drying at 100 ° C. for 30 minutes and at 150 ° C. for 30 minutes to remove the solvent, and then heat-treated at 300 ° C. for 2 hours to initiate a cyclization reaction. A polyimide film was obtained. When the adhesion of this polyimide film to a glass substrate was examined in the same manner as in Example 1, no fifty substrates were peeled off at all. Example 3 17.450 parts by weight of pyromellitic dianhydride and 90 parts by weight of N-methyl-2-pyrrolidone were charged into a reaction flask equipped with a stir bar, a thermometer, and a dropping funnel. Cooled to ° C. The suspension was kept at 10 ° C., and 14.979 parts by weight of 2,2-bis (4-hydroxy-3-aminophenyl) hexafluoropropane and 1,4-
A solution prepared by dissolving 11.692 parts by weight of bis (p-aminophenoxy) benzene in 90 parts by weight of N-methyl-2-pyrrolidone was gradually dropped from a dropping funnel. After dropping, 15 ℃
For 7 hours to synthesize a polyamic acid.

The intrinsic viscosity of the polyamic acid measured in the same manner as in Example 1 was 0.98 dl / g.

Next, the adhesion of the polyimide film obtained from the polyamic acid to the glass substrate was examined in exactly the same manner as in Example 2, and no fifty substrates were peeled off at all. (Example 4) In a reaction flask equipped with a stirring rod, a thermometer, and a dropping funnel, 11.796 parts by weight of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 8.731 of pyromellitic dianhydride were added.
Parts by weight and 100 parts by weight of N, N-dimethylacetamide were charged, sufficiently stirred, and cooled to 10 ° C. This suspension was kept at 10 ° C., and 2,2-bis (4-hydroxy-3-
7.328 parts by weight of aminophenyl) hexafluoropropane and 20.06 parts by weight of 2,2-bis (p-aminophenyl) hexafluoropropane were added to N, N-dimethylacetamide
The solution dissolved in 0 parts by weight was gradually dropped from the dropping funnel. After completion of the dropwise addition, stirring was continued at 15 ° C. for 7 hours to synthesize a polyamic acid.

The intrinsic viscosity of the polyamic acid measured in the same manner as in Example 1 was 1.13 dl / g.

Next, when the adhesion of the polyimide film obtained from polyamic acid to the glass substrate was examined in exactly the same manner as in Example 2, no fifty substrates were peeled off at all. (Comparative Example) 8.728 parts by weight of pyromellitic dianhydride, 3,3 ', in a reaction flask equipped with a stirring rod, a thermometer, and a dropping funnel
4,4'-benzophenonetetracarboxylic dianhydride 1
2.884 parts by weight and N, N-dimethylacetamide 80 parts by weight were charged, sufficiently stirred, and cooled to 10 ° C. The suspension was maintained at 10 ° C., and 16.016 parts by weight of 4,4′-diaminodiphenyl ether was added to N, N-dimethylacetamide 70.
The solution dissolved in parts by weight was gradually dropped from the dropping funnel. After completion of the dropwise addition, stirring was continued at 15 ° C. for 7 hours to synthesize a polyamic acid.

The intrinsic viscosity of this polyamic acid measured in the same manner as in Example 1 was 1.7 dl / g.

Next, the adhesion of the polyimide film obtained from the polyamic acid to the glass substrate was examined in exactly the same manner as in Example 2, and the fifty substrates were completely peeled off.

The light transmittance of a polyimide film having a thickness of 1 μm at a wavelength of 450 nm was 53%.

As described above, the conventional polyimide film not using 2,2-bis (hydroxyaminophenyl) hexafluoropropane as a raw material is inferior in both adhesion to a substrate and light transmittance.

[0047]

As described in detail above, according to the present invention, a polyimide resin having excellent adhesion to a substrate and excellent transparency can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of a polyimide resin in Example 1 of the present invention.

Claims (1)

(57) [Claims] 1. A compound of the general formula (However, Ar is Represents a tetravalent organic group selected from: wherein Z is Embedded image Embedded image Embedded image Represents a divalent organic group selected from: m and n are 0.01 ≦ m
/(M+n)≦1.0.)
A polyimide resin, wherein the intrinsic viscosity at 30 ° C. of a 0.5 g / dl concentration N-methyl-2-pyrrolidone solution of a polyamic acid as a precursor thereof is 0.15 dl / g or more.