JPH0718075A - Heat-resistant resin, production thereof, and varnish containing the same - Google Patents

Abstract

PURPOSE:To obtain the resin which is soluble in a low-boiling solvent with low hygroscopicity and has an extremely high light transmittance by reacting trimellitic anhydride with a polyisocyanate in a specific organic polar solvent. CONSTITUTION:An acid ingredient comprising trimellitic anhydride is reacted with an isocyanate (or amine) ingredient comprising either a polyisocyanate represented by formula I (wherein R<1> and R<2> each is H or a 1-4C alkyl) or the corresponding polyamine in an organic polar solvent having a permittivity as measured at 20 deg.C or 25 deg.C of 5 or higher to obtain the objective poly(amideimide) having repeating units represented by formula II. When a varnish is prepared from this resin, an amide or non-amide solvent may be used in an amount of usually 100-3,000 pts.wt. per 100 pts.wt. the resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyamideimide resin, a method for producing the same and a varnish containing the same. More specifically, the present invention relates to a heat-resistant polyamide-imide resin, which is soluble in a solvent having a low hygroscopic property and a low boiling point and can provide a molded product having a remarkably high light transmittance, a process for producing the same, and a varnish containing the same.

[0002]

2. Description of the Related Art Polyamide-imide resins are widely used as heat-resistant fibers, films, molding materials and the like because of their excellent mechanical properties and heat resistance. However, heat-resistant resins such as polyimide and polyamide-imide currently used are only soluble in highly hygroscopic amide solvents,
The stability over time during molding was poor. Further, during molding such as wet spinning, the molded product is whitened or voids are formed by water absorbed by the solvent, so that it is difficult to bring out the excellent mechanical properties originally possessed by polyamide-imide. Furthermore, in general, products of polyimide and polyamide-imide are colored in dark yellowish brown, for example,
When it is formed into a fiber or the like, it has a drawback that its coloring property is significantly limited. Also, the dry film after coating is colored yellow even though it has excellent transparency.
In the field of liquid crystal alignment films and the like, which are required to have colorless transparency, they have not been completely satisfactory.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a product which is soluble in a solvent having a low boiling point and a low hygroscopicity, in addition to the heat resistance inherent to polyamideimide, and which has a remarkably high light transmittance. It is an object of the present invention to provide a possible polyamide-imide resin.

[0004]

The present inventors have accomplished the present invention as a result of earnest research for achieving the above object. That is, the present invention provides the following general formula (I):

[0005]

[Chemical 3]

The present invention relates to a polyamideimide resin having a repeating unit represented by the formula (wherein R ¹ and R ² may be the same or different and each represents hydrogen or an alkyl group having 1 to 4 carbon atoms).

The present invention also provides an acid component containing trimellitic anhydride as an essential component and the following general formula (II):

[0008]

[Chemical 4]

(Wherein R ¹ and R ² may be the same or different and each represents hydrogen or an alkyl group having 1 to 4 carbon atoms) or a polyamine corresponding thereto as an essential component. The present invention relates to a method for producing a polyamideimide resin having a repeating unit (I), which comprises reacting an isocyanate (amine) component in an organic polar solvent having a dielectric constant of 5 or more measured at 20 ° C. or 25 ° C.

Further, the present invention relates to a polyamideimide varnish obtained by dissolving a polyamideimide having a repeating unit (I) in a polar solvent.

R ¹ and R ² in the repeating unit represented by the general formula (I) may be the same or different and each is hydrogen or an alkyl group having 1 to 4 carbon atoms, preferably a methyl group.

A feature of the polyamide-imide of the present invention is that it can be polymerized in a solvent having a relatively low hygroscopicity and can provide a product having a remarkably high light transmittance without impairing heat resistance. Polyamideimide having such characteristics is an organic polar solvent other than the highly hygroscopic amide-based solvent such as dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone, and has a relatively large dielectric constant. By using trimellitic anhydride or its reactive derivative as a monomer, and a compound of the formula (II):

[0013]

[Chemical 5]

When a polyisocyanate represented by or a polyamine corresponding thereto is used, it can be easily obtained.

The polyamideimide of the present invention can be produced by a usual method such as an isocyanate method and an acid chloride method, but the isocyanate method is most suitable from the viewpoint of polymerizability and cost. When the polyamideimide of the present invention is produced by the isocyanate method, diglyme which cannot be used in the conventional polyamideimide production, ether solvents such as tetrahydrofuran, cyclohexanone, ketone solvents such as methylethylketone, propionitrile, acetonitrile, etc. A non-amide solvent having a relatively high dielectric constant such as a nitrile solvent, a nitro solvent such as nitromethane or nitroethane, an ester solvent such as γ-butyrolactone or cellosolve acetate can be used. The polar solvent having a relatively high dielectric constant means one having a dielectric constant of 5 or more, preferably 15 or more, measured at 20 ° C. or 25 ° C. The non-amide solvent is not limited to these. It is desirable to use these alone or as a mixture. Furthermore, it is also possible to use a solvent having a low dielectric constant, such as xylene or toluene, having a dielectric constant of less than 5 measured at 20 ° C. or 25 ° C. in addition to the polar solvent having a relatively high dielectric constant. Also, a small amount of water, a metal salt such as lithium bromide, lithium chloride, or the like may be added to the above solvent. Furthermore, an amide solvent such as dimethylformamide that has been conventionally used,
Needless to say, sulfur-based solvents such as dimethyl sulfoxide and sulfolane, tetramethylurea and the like can also be used as the polymerization solvent of the present invention. The polymerization solvent is
They may be used alone or as a mixture.

The reaction temperature is usually preferably 50 to 200 ° C. The reaction is carried out in the presence of a catalyst for the reaction of isocyanate with an active hydrogen compound, for example, a tertiary amine, an alkali metal compound, an alkaline earth metal compound, or a metal such as cobalt, titanium, tin or zinc, or a semimetal compound. You can go. The reaction pressure is usually atmospheric pressure, but it may be carried out under pressure.

In obtaining the polyamideimide of the present invention, it is essential to use trimellitic anhydride as an acid component monomer.

In addition to trimellitic anhydride, acid components that may be added to impart solubility or polymerizability to a solvent include, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and pimeline. Acids, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid and other aliphatic dicarboxylic acids, isophthalic acid, 5-tert-butyl-1,3-benzenedicarboxylic acid, Terephthalic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylmethane-2,4'-dicarboxylic acid, diphenylmethane-
3,4'-dicarboxylic acid, diphenylmethane-3,3 '
-Dicarboxylic acid, 1,2-diphenylethane-4,4 '
-Dicarboxylic acid, 1,2-diphenylethane-2,4 '
-Dicarboxylic acid, 1,2-diphenylethane-3,4 '
-Dicarboxylic acid, 1,2-diphenylethane-3,3 '
-Dicarboxylic acid, 2,2-bis (4-carboxyphenyl) propane, 2- (2-carboxyphenyl) 2-
(4-Carboxyphenyl) propane, 2- (3-carboxyphenyl) 2- (4-carboxyphenyl) propane, 2,2-bis (3-carboxyphenyl) propane, diphenylether-4,4-dicarboxylic acid, diphenylether- 2,4-dicarboxylic acid, diphenyl ether-3,4-dicarboxylic acid, diphenyl ether-
3,3-dicarboxylic acid, diphenyl sulfide-4,4
-Dicarboxylic acid, diphenyl sulfide-2,4-dicarboxylic acid, diphenyl sulfide-3,4-dicarboxylic acid, diphenyl sulfide-3,3-dicarboxylic acid, diphenyl sulfone-4,4-dicarboxylic acid, diphenyl sulfone-2,4 -Dicarboxylic acid, diphenylsulfone-3,4-dicarboxylic acid, diphenylsulfone-3,3
-Dicarboxylic acid, benzophenone-4,4-dicarboxylic acid, benzophenone-2,4-dicarboxylic acid, benzophenone-3,4-dicarboxylic acid, benzophenone-3,
3-dicarboxylic acid, 1,1,3-trimethyl-5-carboxy-3- (p-carboxyphenyl) indane, pyridine-2,6-dicarboxylic acid, bis [(4-carboxy) phthalimide] -4,4 ′ -Diphenyl ether,
Bis [(4-carboxy) phthalimide] -α, α'-
Aromatic dicarboxylic acids such as metaxylene, butane-1,
2,4-tricarboxylic acid, naphthalene-1,2,4-tricarboxylic acid and their anhydrides, butane-1,2,
3,4-tetracarboxylic acid, cyclobutane-1,2,
3,4-tetracarboxylic acid, benzene-1,2,4,5
-Tetracarboxylic acid (pyromet acid), benzophenone-3,3 ', 4,4'-tetracarboxylic acid, diphenyl ether-3,3', 4,4'-tetracarboxylic acid, benzene-1,2,3,4 -Tetracarboxylic acid, biphenyl-3,3 ', 4,4'-tetracarboxylic acid, biphenyl-2,2', 3,3'-tetracarboxylic acid, naphthalene-2,3,6,7-tetracarboxylic acid , Naphthalene-
1,2,4,5-tetracarboxylic acid, naphthalene-1,
4,5,8-Tetracarboxylic acid, decahydronaphthalene-1,4,5,8-tetracarboxylic acid, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1, 2,5,6-tetracarboxylic acid, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid,
2,7-Dichloronaphthalene-1,4,5,8-tetracarboxylic acid, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic acid, phenanthrene-1,3,9 , 10-Tetracarboxylic acid, perylene-
3,4,9,10-tetracarboxylic acid, bis (2,3-
Dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane, 1,1-bis (2,3-dicarboxyphenyl) ethane, 1,1-bis (3,4-dicarboxyphenyl) ethane, 2,2-bis (2,3-
Dicarboxyphenyl) propane, 2,3-bis (3,3
4-dicarboxyphenyl) propane, bis (3,4-
Dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, cyclopentane-1,
2,3,4-tetracarboxylic acid, pyrrolidine-2,3
4,5-tetracarboxylic acid, pyrazine-2,3,5,6
-Tetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, 2,3,5-tricarboxycyclopentyl acetic acid, ethylene glycol bis (anhydro trimellitate), propylene glycol bis (anhydro trimellitate) ) And dianhydrides thereof. These are used alone or as a mixture of two or more kinds. The acid component which may be copolymerized is used within a range in which the effects of the present invention can be achieved.
It is used in an amount of 0 mol% or less, preferably 30% or less.

As the diisocyanate (amine) component, the following general formula (II):

[0020]

[Chemical 6]

(Wherein R ¹ and R ² are as defined above), or, for example, bis [aminocyclohexyl] methane, bis [aminocyclohexyl] propane, etc., represented by the following general formula (III):

[0022]

[Chemical 7]

It is essential to use a diamine represented by the formula (wherein R ¹ and R ² are as defined above).

Further, as an amine (isocyanate) component, 1,3-bis (aminomethyl) cyclohexane,
1,4-bis (aminomethyl) cyclohexane, m-phenylene, p-phenylenediamine, oxydianiline, methylenedianiline, hexafluoroisoprolidene dianiline, a, a′-diamino-m-xylene,
a, a'-diamino-p-xylene, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2,7-naphthalenediamine, 2,
2'-bis (4-aminophenyl) propane, 2,2 '
-Bis (4-aminophenyl) hexafluoropropane, 4,4'-diaminodiphenyl sulfone, 3,3 '
-Diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,4'-diaminobiphenyl,
4,4'-diaminobenzophenone, hexamethylenediamine, tetramethylenediamine, isophoronediamine, 5-amino-1- (4'-aminophenyl) -1,
3,3'-trimethylindane, 3,4'-diaminodiphenyl ether, isopropylidenedianiline, 3,
3'-diaminobenzophenone, 4,4'-diaminocyclohexyl, o-tolidine, 2,4-tolylenediamine, 1,3-bis (3-aminophenoxy) benzene,
1,3-bis (4-aminophenoxy) benzene, 1,
4-bis (4-aminophenoxy) benzene, 4,4 '
-[1,3-phenylenebis (1-methylethylidene)] bisaniline, 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 3,
3 ′-[1,3-phenylenebis (1-methylethylidene)] bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone , Bis [4- (3
-Aminophenoxy) phenyl] sulfone, 4,4'-
Bis (4-aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 4,4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfide, 6-
Amino-1- (4′-aminophenyl) -1,3,3-
Trimethylindane or a diisocyanate corresponding thereto may be copolymerized alone or as a mixture of two or more kinds. The amine or isocyanate that may be copolymerized is used in a range that does not impair the characteristics of the polyamide-imide of the present invention, but is usually 50 mol% or less, preferably 30 mol% in all amine (isocyanate) components.
Used below.

The molecular weight of the polyamideimide of the present invention is N
The logarithmic viscosity value at 30 ° C. in methyl-2-pyrrolidone is 0.1 to 2.5 dl / g, preferably 0.4 to 1.5 dl / g.

The polyamideimide of the present invention is not only dissolved in an ordinary amide polar solvent such as dimethylformamide, dimethylacetamide, diethylacetamide, N-methyl-2-pyrrolidone and hexamethylphosphoamide which is a solvent for polyamideimide. No, dioxane that could not be dissolved in the conventional polyamide-imide polymer,
Ether organic solvents such as diglyme and tetrahydrofuran, hydrocarbon organic solvents such as toluene and xylene, ketone organic solvents such as cyclohexanone, cyclopentanone, methyl ethyl ketone and methyl isobutyl ketone, and other non-isophorone, acetonitrile and γ-butyrolactone It is also soluble in amide polar solvents. Of these, diglyme, tetrahydrofuran, and cyclohexanone are preferably used from the viewpoints of the dielectric constant of the solvent, the solubility in the polymer, and the toxicity.

When the polyamideimide of the present invention is used as a varnish, the above-mentioned amide-based solvent and non-amide-based solvent can be used. The ratio of the polyamide-imide and the solvent is appropriately determined depending on the purpose of use and the like, but usually the solvent is used in an amount of 100 to 3,000 parts by weight, preferably 300 to 1,000 parts by weight, based on 100 parts by weight of the polyamideimide.

The polyamideimide resin of the present invention can be molded by a conventionally known method such as solution casting, dry spinning, wet spinning, gel spinning, melt spinning, melt molding and injection molding. In particular, in the case of solution casting such as solution casting and dry spinning, the solvent used has a low boiling point and low hygroscopicity, so handling is excellent, and the physical properties of the resulting molded article are those molded from conventional amide solvents. Is far superior to.

Although the form of the molded product is not particularly limited, it may be a molded product such as a film, a fiber, a hollow fiber, a pipe or a bottle. The use is also not particularly limited, but it can be used as parts and materials for automobiles, chemical plants, aviation / space, machines, electric / electronics.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0031]

Example 1 A reactor was charged with the following polymerization components, and the temperature was raised to 150 ° C. in about 30 minutes while stirring. After stirring at 150 ° C. for about 20 hours, the reaction was stopped. Polymerization component trimellitic anhydride 1 mol 4,4′-dicyclohexylmethane diisocyanate 0.8 mol m-xylene diisocyanate 0.2 mol γ-butyrolactone 0.2 liter The above polyamideimide solution was placed on a 100 μm thick releasable polyester film. Was cast-coated to a dry thickness of 30 μm, dried at 100 ° C. for 5 minutes and 150 ° C. for 30 minutes, and then peeled off from the release film. afterwards,
To completely remove the solvent, it was heated at 200 ° C. under reduced pressure for about 3 hours. Table 1 shows various physical properties of the polyamide-imide film thus obtained. The polyamideimide polymerization solution was diluted with N-methyl-2-pyrrolidone and then reprecipitated in methanol to obtain polyamideimide powder. The solubility of the powder thus obtained was investigated. The measuring method is shown below. Tg (° C.) and coefficient of thermal expansion: According to TMA tensile measurement method. Load: 1 g, sample size: 5 × 20 mm Temperature rising temperature: measured at 10 ° C./min. Light transmittance: A film with a thickness of 25 μm is used, and the wavelength is 50
Measured at 0 nm. Tensile strength and tensile elongation: According to JIS-C-2318. Tensile modulus: According to JIS-C-2318. Solubility: Polymer powder (diameter: 2-3 μm) was mixed with a solvent so that the concentration was 20% by weight, stirred at room temperature, and visually observed.

Examples 2, 3 As the isocyanate component, 4,4'-dicyclohexylpropane diisocyanate (Example 2) or 4,4'-dicyclohexylpropane diisocyanate
Polyamideimide was produced by the same procedure as in Example 1 except that 4′-dicyclohexylpropane diisocyanate and isophorone diisocyanate were used in a ratio of 0.7 mol: 0.3 mol (Example 3). The physical properties of the obtained polyamideimide were measured in the same manner as in Example 1. The results are shown in Table 1.
Shown in.

[0033]

[Table 1]

[0034]

INDUSTRIAL APPLICABILITY The polyamide-imide of the present invention is not only heat-resistant but also soluble in general-purpose solvents having a low hygroscopicity and a low boiling point, which cannot be used conventionally. Therefore, the solution moldability is excellent, and the molded products such as the film and the fiber exhibit extremely high light transmittance and are substantially colorless and transparent.

Front page continued (72) Inventor Hideo Nishino 1-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd.

Claims (5)

[Claims] 1. The following general formula (I): (In the formula, R ¹ and R ² may be the same or different,
A polyamide-imide resin having a repeating unit represented by hydrogen or an alkyl group having 1 to 4 carbon atoms). 2. An acid component containing trimellitic anhydride as an essential component and the following general formula (II): (In the formula, R ¹ and R ² may be the same or different,
A polyisocyanate represented by hydrogen or an alkyl group having 1 to 4 carbon atoms) or an isocyanate (amine) component having a corresponding polyamine as an essential component at 20 ° C or 25 ° C has a dielectric constant of 5 or more. 2. The method for producing a polyamide-imide resin according to claim 1, wherein the reaction is carried out in the organic polar solvent. 3. The method according to claim 2, wherein the organic polar solvent is a non-amide organic polar solvent. 4. A polyamide-imide varnish containing the polyamide-imide resin according to claim 1 in a polar solvent. 5. The polyamide-imide varnish according to claim 4, wherein the organic polar solvent is a non-amide organic polar solvent.