JPH07173287A - Polyimide soluble in organic solvent - Google Patents

Abstract

PURPOSE:To provide a polyimide excellent in mechanical characteristics, undergoing less discoloration and soluble in an organic solvent. CONSTITUTION:This polyimide is composed mainly of a polyimide component obtained by the reaction of an amine compound of formula I (wherein n is 0 or 1) with an acid anhydride of formula II (wherein Y is C=O or O).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide which has excellent mechanical properties such as elastic modulus and elongation, is colorless or pale yellow and is soluble in an organic solvent.

[0002]

2. Description of the Related Art Polyimide has been attracting attention in recent years as a coating agent for engineering plastics and etching because of its excellent mechanical properties and heat resistance.
However, most of them are not soluble in organic solvents. Some of them are soluble in an amide-based solvent such as NMP (N-methyl-2-pyrrolidone) and a high boiling solvent such as m-cresol, but the number thereof is small. Therefore, the workability was extremely low, and the usable materials were limited. Many of the colors are dark brown, and it is often difficult to use for coating applications where color tone is a problem.

[0003]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and an object thereof is to:
It is intended to provide a polyimide which is excellent in mechanical properties such as solubility in a solvent and elongation in elastic modulus, and has a color close to colorless and transparent.

[0004]

Means for Solving the Problems As a result of intensive studies to overcome the above-mentioned conventional drawbacks, the inventors of the present invention introduced a specific structure into the structure, thereby making the polyimide soluble in an organic solvent. I found what I could prepare for. That is,
The present invention is an organic solvent-soluble polyimide having a polyimide component as a main component, which is obtained by reacting the amine compound shown in Chemical formula 3 with the acid anhydride shown in Chemical formula 4.

[Chemical 3]

[0005]

[Chemical 4] The polyimide of the present invention has a specific amine component of 4,
4'-diaminodiphenylpropane, 3,4'-diaminodiphenylpropane, 4,4 '-[1,3-phenylenebis (1-methylidene)] bisaniline, 4,4'-
At least one component of [1,4-phenylenebis (1-methylidene)] bisaniline can be mentioned, and specific acid anhydride components include 4,4′-oxydiphthalic acid dianhydride, 3,3 ′, 4. , 4'-benzophenone tetracarboxylic acid dianhydride.

As the amine component to be copolymerized, p-phenylenediamine, m-phenylenediamine, chloro-p-
Phenylenediamine, 4,4'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 3,
4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane, 4,4 '
-Diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,4 '
-Diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3'-dimethylbenzidine, 3,3 ',
5,5'-tetramethylbenzidine, 3,3'-dichlorobenzidine, 2,2'-dichlorobenzidine, 3,
3 ', 5,5'-tetrachlorobenzidine, 2,4-bis (β-amino-t-butyl) toluene, bis (p-β
Aromatic diamines such as -amino-t-butylphenyl) ether can be mentioned.

As the acid anhydride component, pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 1 , 2,5,6-Naphthalenetetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 2,3,4,5-thiophenetetracarboxylic dianhydride, 2 , 2-bis (3,4-dicarboxyphenyl) propanoic acid dianhydride, bis (3,4-dicarboxyphenyl) sulfonic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride Homoaromatic carboxylic acid dianhydrides can be copolymerized.

When the above-mentioned aromatic diamine or aromatic carboxylic dianhydride is copolymerized, the solubility becomes insufficient, so it is desirable to keep the aromatic polyimide component at 50 mol% or less.

The method for synthesizing the polyimide of the present invention is a conventionally used method, that is, a method for obtaining a polyimide by taking out polyamic acid as a film or fiber from a polyamic acid dope solution obtained by a low temperature solution polymerization method and subjecting it to heat treatment. A method of heating the acid dope solution to obtain a polyimide solution can be adopted.

Examples of the present invention will be described below.

【Example】

(Synthesis of Polyimide A) 4,4 ′-[1,3-Phenylenebis (1-methylidene)] bisaniline (4.2094 g) was placed in a 100 ml four-necked flask, and 20 ml of dry N-methyl-2-pyrrolidone was added under a dry nitrogen atmosphere. 2. Put it in, dissolve it completely with stirring at 20 ° C., and keep it below 25 ° C. 4,4′-oxydiphthalic acid dianhydride 3.
8096 g was gradually added, and 12 ml of dried N-methyl-2-pyrrolidone was further added. Stirring was continued for about 6 hours to obtain a polyamic acid dope solution. Logarithmic viscosity is 2.05d / g
(30 ° C.). This dope solution was cast on a glass plate with a film coater, dried with hot air, and heat-treated at 240 ° C. for 6 hours. The prepared film (thickness 32μ
The imide of m) was confirmed by IR spectrum. As a result of the tensile test, the elastic modulus was 2.8 × 10 4 kgf / cm ² and the elongation rate was 18.2%. Dissolved in.

The polyimides B to J obtained by the same manufacturing method are shown in Table 1. Table 1 shows the solubility of the polyimide obtained by the same production method.

[0012]

[Table 1]

* BAM; 4,4 '-[1,3-phenylenebis (1-methylidene)] bisaniline BAP; 4,4'-[1,3-phenylenebis (1-methylidene)] bisaniline 3,4- DDP; 3,4'-diaminodiphenylpropane 4,4-DDP; 4,4'-diaminodiphenylpropane PPD; p-phenylenediamine OPAN; 4,4'-oxydiphthalic acid dianhydride BTAN; 3,3 ', 4 , 4'-Benzophenonetetracarboxylic acid dianhydride BPAN; 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride ** The numbers indicate the molar ratio. H dissolved both amines simultaneously and then both acid anhydrides were added simultaneously. When J started reacting with PPD by reacting BPAN,
4-DDP and OPAN were added in this order.

[0014]

[Table 2]

[0015]

INDUSTRIAL APPLICABILITY The polyimide of the present invention forms a coating film having excellent solubility in organic solvents and excellent mechanical properties, and its color is pale yellow or almost colorless, and is useful as various coating agents.

[Brief description of drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of polyimide A of an example.

FIG. 2 is a diagram showing an infrared absorption spectrum of polyimide B of an example.

FIG. 3 is a diagram showing an infrared absorption spectrum of polyimide C of an example.

Claims (1)

[Claims] 1. An organic solvent-soluble polyimide containing a polyimide component as a main component, which is obtained by reacting an amine compound shown in Chemical formula 1 with an acid anhydride shown in Chemical formula 2. [Chemical 1] [Chemical 2]