JPH1017658A - Polyarylate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyarylate having excellent electrical properties, being amorphous and considerably soluble in a solvent, giving a coating fluid having storage stability and being desirable as especially an electronic material by using a specified dihydric phenol and specifying the carboxyl value ascribable to the terminal carboxyl groups. SOLUTION: This polyarylate comprises a dihydric phenol and an aromatic dicarboxylic acid. The dihydric phenol comprises 10-90mol%, based on the total phenol content, dihydric phenol represented by the formula [wherein R1 to R8 are each a group selected among hydrogen, halogens, 1-4C hydrocarbon groups and 1-4C alkoxyls, and at least one of them is a group other than hydrogen]. This polyarylate has a terminal-carboxyl value of 20mol/ton or below and can dissolve in methylene chloride to form a solution having a concentration of 10wt.% or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyarylate containing a specific dihydric phenol unit, having a small number of carboxyl end groups, having good solubility in a solvent, and having excellent electric properties, and is particularly preferably used for electronic materials. It relates to a polyarylate that can be used.

[0002]

2. Description of the Related Art Amorphous polyarylate comprising residues of 2,2-bis (4-hydroxyphenyl) propane [bisphenol A] and residues of terephthalic acid and isophthalic acid is already well known as an engineering plastic. I have. Such polyarylate has high heat resistance,
Excellent mechanical strength and dimensional stability represented by impact strength,
In addition, since it is amorphous and transparent, the molded product is widely applied to fields such as electric / electronic, automobile, and machine.

Further, polyarylate made from bisphenol A is used as a film for a capacitor or a resin for a binder of an electrophotographic photosensitive member by utilizing its excellent electric characteristics (insulating property, dielectric property, etc.). Applications to various electronic materials are being performed.

[0004] However, the demands for electrical characteristics in electronic material applications have become more and more severe, and polyarylate made from bisphenol A has been used in some applications with insufficient electrical characteristics. Under these circumstances, there is a demand for polyarylate having more excellent electrical properties.

[0005] Further, in applications where the composition is used by dissolving in a solvent, such as the above-mentioned binder resin and casting film, not only the electric properties but also the amorphous and good solubility in the solvent, and the It is also necessary to have storage stability at the time of doing.

Under these circumstances, polyarylates for electronic materials which are excellent in electrical properties, are amorphous, have excellent solvent solubility, and have excellent storage stability when used as a coating solution, are required. It has come.

[0007]

DISCLOSURE OF THE INVENTION In view of the above situation, an object of the present invention is to provide a polyarylate made from bisphenol A as a raw material, which has more excellent electrical properties and is amorphous and is not suitable for use in a solvent. An object of the present invention is to provide a polyarylate that has good solubility and storage stability when used as a coating liquid, and can be particularly preferably used for electronic materials.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve such problems, and as a result, the electrical properties of polyarylate are determined by the two benzene rings of dihydric phenol constituting polyarylate. And the carboxyl number at the end of the polymer. In other words, a biallylic derivative having no hydrogen atom in the bond between the two benzene rings of the dihydric phenol is copolymerized, and a polyarylate having a carboxyl value of a specific value or less is found to be extremely stable electrically. Further, among the dihydric phenols, at least one of
First, they have found that a polyarylate copolymerized with a compound having a substituent other than a hydrogen atom is excellent in solubility in a solvent and storage stability of a coating solution, and have reached the present invention.

That is, the gist of the present invention is a polyarylate comprising a dihydric phenol and an aromatic dicarboxylic acid, wherein the dihydric phenol is represented by the following general formula (1)

[0010]

Embedded image

[In the formula, R _{1 to} R ₈ each independently represent a group selected from a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. , R _{1 to} R ₈ represent a substituent other than a hydrogen atom. And the terminal carboxyl number is not more than 20 mol / ton, and the solubility in methylene chloride is not less than 10% by weight. It is a polyarylate characterized by having.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polyarylate of the present invention comprises a dihydric phenol and an aromatic dicarboxylic acid, and the dihydric phenol constituting the polyarylate of the present invention has the following general formula (1)

[0013]

Embedded image

[Wherein, R _{1 to} R ₈ each independently represent a group selected from a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. , R _{1 to} R ₈ represent a substituent other than a hydrogen atom. ] As an essential component.

Specific examples of the dihydric phenol represented by the general formula (1) are as follows. 2-methyl-4,4'-dihydroxybiphenyl, 3-methyl-4,4'-dihydroxybiphenyl, 2-chloro-4,4'-dihydroxybiphenyl, 3-chloro-4,4'-dihydroxybiphenyl, 3, 3'-dimethyl-4,4'-dihydroxybiphenyl, 2,2'-dimethyl-4,4'-dihydroxybiphenyl, 2,3'-dimethyl-4,4'-dihydroxybiphenyl, 3,3'-dichloro- 4,4′-dihydroxybiphenyl, 3,3′-di-tert-butyl-4,4′-dihydroxybiphenyl, 3,3′-dimethoxy-4,4′-dihydroxybiphenyl,
3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl, 3,3 ′, 5,5′-tetra-tert
-Butyl-4,4'-dihydroxybiphenyl, 3,
3 ', 5,5'-tetrachloro-4,4'-dihydroxybiphenyl, 2,2'-dihydroxy-3,3'-dimethylbiphenyl, 3,3'-difluoro-4,4'-
Biphenol, 2,2'-dihydroxy-3,3 ',
5,5′-tetramethylbiphenyl, 3,3 ′, 5
5'-tetrafluoro-4,4'-biphenol, 2,
2 ', 3,3', 5,5'-hexamethyl-4,4'-
Biphenol and the like can be exemplified, and these may be used alone or in combination of two or more. Among them, 3,3′-dimethyl-4,4′- is particularly preferable.
Dihydroxybiphenyl, 2,2′-dimethyl-4,
4'-dihydroxybiphenyl, 3,3 ', 5,5'-
Tetramethyl-4,4'-dihydroxybiphenyl,
2,2′-dihydroxy-3,3′-dimethylbiphenyl, 2,2′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl, 2,2 ′, 3,3 ′, 5,5 ′
-Hexamethyl-4,4'-biphenol.

Other dihydric phenols copolymerized with the dihydric phenol represented by the general formula (1) constituting the polyarylate of the present invention include bis (4-hydroxyphenyl) methane and 1,1- Bis (4-hydroxyphenyl) ethane, bis (4-methyl-2-hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-
Hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxy Phenyl) -1-
Phenylethane, 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, bis (3-methyl-4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4
-Hydroxyphenyl) -2-methylpropane, bis (4-hydroxyphenyl) phenylmethane, 2,2-
Bis (4-hydroxyphenyl) octane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 2,2-bis (3-allyl-4-hydroxyphenyl) propane, 2,2-bis (3 -Isopropyl-4
-Hydroxyphenyl) propane, 2,2-bis (3-
tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (3-sec-butyl-4-hydroxyphenyl) propane, 1,1-bis (2-methyl-4)
-Hydroxy-5-tert-butylphenyl) -2-
Methylpropane, 4,4 '-[1,4-phenylene-bis (1-methylethylidene)] bis (3-methyl-4-
Hydroxyphenyl), 1,1-bis (3-phenyl-
4-hydroxyphenyl) cyclohexane, bis (2-
(Hydroxyphenyl) methane, 2,4′-methylenebisphenol, bis (3-methyl-4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl)
Propane, 1,1-bis (2-hydroxy-5-methylphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -3-methyl-butane, bis (2-hydroxy-
3,5-dimethylphenyl) methane, 1,1-bis (4
-Hydroxyphenyl) cyclopentane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclopentane, 3,3-bis (4-hydroxyphenyl) pentane, 3,3-bis (3-methyl-4- Hydroxyphenyl) pentane, 3,3-bis (3,5-dimethyl-4-)
Hydroxyphenyl) pentane, 2,2-bis (2-hydroxy-3,5-dimethylphenyl) propane, 2,
2-bis (4-hydroxyphenyl) nonane,

1,1-bis (3-methyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 2,2-bis (4 -Hydroxyphenyl) decane, 1,1-bis (4-hydroxyphenyl) decane, 1,1-bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane, bis (4-hydroxyphenyl) diphenylmethane , Terpene diphenol, 1,1-bis (3-tert-butyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (2-methyl-4-hydroxy-5-tert-butylphenyl) -2-methylpropane 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, bis (3,5-di-tert-butyl) Le 4-hydroxyphenyl) methane, bis (3,5-di -sec- butyl-4
-Hydroxyphenyl) methane, 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (2-hydroxy-3,5-di-te
rt-butylphenyl) ethane, 1,1-bis (3-nonyl-4-hydroxyphenyl) methane, 2,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 1,1 -Bis (2-hydroxy-3,
5-di-tert-butyl-6-methylphenyl) methane, 1,1-bis (3-phenyl-4-hydroxyphenyl) -1-phenylethane, butyl α, α′-bis (4-hydroxyphenyl) acetate Ester, 1,1-bis (3-fluoro-4-hydroxyphenyl) methane, bis (2-hydroxy-5-fluorophenyl) methane,
2,2-bis (3-fluoro-4-hydroxyphenyl) propane,

1,1-bis (3-fluoro-4-hydroxyphenyl) -1-phenylmethane, 1,1-bis (3-fluoro-4-hydroxyphenyl) -1- (p
-Fluorophenyl) methane, 1,1-bis (4-hydroxyphenyl) -1- (p-fluorophenyl) methane, 2,2-bis (3-chloro-4-hydroxy-5-
Methylphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-
Bis (3-chloro-4-hydroxyphenyl) propane, 1,1-bis (3,5-dibromo-4-hydroxyphenyl) methane, 2,2-bis (3,5-dibromo-
4-hydroxyphenyl) propane, 2,2-bis (3
-Nitro-4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) dimethylsilane, bis (2,3,5-trimethyl-4-hydroxyphenyl)
-1-phenylmethane, 2,2-bis (4-hydroxyphenyl) dodecane, 2,2-bis (3-methyl-4-
Hydroxyphenyl) dodecane, 2,2-bis (3,5
-Dimethyl-4-hydroxyphenyl) dodecane, 1,
1-bis (3-tert-butyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (3,5-
Di-tert-butyl-4-hydroxyphenyl) -1
-Phenylethane, 1,1-bis (2-methyl-4-hydroxy-5-cyclohexylphenyl) -2-methylpropane, 1,1-bis (2-hydroxy-3,5-di-tert-butylphenyl) Ethane, 2,2-bis (4-hydroxyphenyl) propanoic acid methyl ester, 2,2-bis (4-hydroxyphenyl) propanoic acid ethyl ester, 2,2 ′, 3,3 ′, 5,5′-hexamethyl -4,4'-biphenol, bis (2-hydroxyphenyl) methane, 2,4'-methylenebisphenol, 1,2-bis (4-hydroxyphenyl) ethane, 2- (4-hydroxyphenyl) -2- ( 2-hydroxyphenyl) propane, bis (2-hydroxy-3)
-Allylphenyl) methane, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane, 1,1-bis (2-hydroxy-5-tert-butylphenyl) ethane, bis ( 2-hydroxy-5-phenylphenyl) methane, 1,1-bis (2-methyl-
4-hydroxy-5-tert-butylphenyl) butane, bis (2-methyl-4-hydroxy-5-cyclohexylphenyl) methane, 2,2-bis (4-hydroxyphenyl) pentadecane, 2,2-bis (3 -Methyl-4-hydroxyphenyl) pentadecane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) pentadecane, 1,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) Ethane, bis (2-hydroxy-3,5-di-tert-butylphenyl) methane, 2,2-bis (3-styryl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl)- 1- (p-nitrophenyl) ethane, bis (3
5-difluoro-4-hydroxyphenyl) methane, bis (3,5-difluoro-4-hydroxyphenyl)-
1-phenylmethane, bis (3,5-difluoro-4-
Hydroxyphenyl) diphenylmethane, bis (3-fluoro-4-hydroxyphenyl) diphenylmethane,
2,2-bis (3-chloro-4-hydroxyphenyl)
Propane, 1,1-bis (4-hydroxyphenyl)-
3,3-dimethyl-5-methyl-cyclohexane, 1,
1-bis (4-hydroxyphenyl) -3,3-dimethyl-5,5-dimethyl-cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3-dimethyl-4-
Methyl-cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3-dimethyl-5-ethyl-cyclohexane, 1,1-bis (4-hydroxyphenyl)-
3,3-dimethyl-5-methyl-cyclopentane, 1,
1-bis (3,5-dimethyl-4-hydroxyphenyl) -3,3-dimethyl-5-methyl-cyclohexane, 1,1-bis (3,5-diphenyl-4-hydroxyphenyl) -3,3- Dimethyl-5-methyl-cyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) -3,3-dimethyl-5-methyl-cyclohexane, 1,1-bis (3-phenyl-4-hydroxyphenyl ) -3,3-Dimethyl-5-methyl-cyclohexane, 1,1-bis (3,5-dichloro-4-hydroxyphenyl) -3,3-dimethyl-5-methyl-cyclohexane, 1,1-bis ( 3,5-dibromo-4-hydroxyphenyl) -3,3-dimethyl-5-methyl-
Cyclohexane, 1,4-di (4-hydroxyphenyl) -p-menthane, 1,4-di (3-methyl-4-hydroxyphenyl) -p-menthane, 1,4-di (3,
Terpene diphenols such as 5-dimethyl-4-hydroxyphenyl) -p-menthane and the like can be mentioned. These dihydric phenols can be used alone or in combination of two or more.

Particularly preferred are 2,2-bis (4-hydroxyphenyl) propane (bisphenol A),
2-bis (3-methyl-4-hydroxyphenyl) propane (bisphenol C), 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z),
1,1-bis (4-hydroxyphenyl) -1-phenylethane (bisphenol AP).

The ratio of copolymerizing the dihydric phenol represented by the general formula (1) is determined in consideration of desired electric characteristics and solubility in a solvent described below. 10 to 90 mol%, preferably 15 to 60 mol%
It is. 90, depending on the type of dihydric phenol to be copolymerized
When the amount is more than mol%, solubility in a solvent and storage stability may be deteriorated. When the amount is less than 10% by mol, electric characteristics may not be sufficiently exhibited.

In addition, ethylene glycol, propylene glycol, butanediol, and dihydric phenol copolymerizable within a range that does not impair the electrical properties and solubility of the polymer
It may be replaced with a dihydric alcohol such as pentanediol, hexanediol, heptanediol, octanediol, dodecanediol, neopentyl glycol, cyclohexanediol, and 1,4-dihydroxymethylcyclohexane.

Examples of the divalent carboxylic acid used for producing the polyarylate of the present invention include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 3-tert-butylisophthalic acid, Diphenic acid, 4,4′-dicarboxydiphenyl ether, bis (p-carboxyphenyl) alkane,
Aromatic dicarboxylic acids such as 4,4'-dicarboxyphenyl sulfone are exemplified. These divalent carboxylic acids can be used alone or in combination of two or more. The divalent carboxylic acid that can be particularly preferably used is a mixture of equal amounts of terephthalic acid and isophthalic acid.

The polyarylate of the present invention does not necessarily need to be a linear polymer, and may have a branched structure by adding a substance having three or more functions at the time of polymerization.

Examples of the terminal blocking material include monovalent phenols such as phenol, cresol and p-tert-butylphenol; monovalent acid chlorides such as benzoic acid chloride, methanesulfonyl chloride and phenylchloroformate; Methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, pentanol, hexanol, dodecyl alcohol, stearyl alcohol, benzyl alcohol,
Monohydric alcohols such as phenethyl alcohol, acetic acid,
Propionic acid, octanoic acid, cyclohexanecarboxylic acid, benzoic acid, toluic acid, phenylacetic acid, p-ter
Monovalent carboxylic acids such as t-butylbenzoic acid and p-methoxyphenylacetic acid are exemplified.

As a method for producing the polyarylate of the present invention, a solution polymerization method (A. Conix I) in which a divalent carboxylic acid halide and a divalent phenol are reacted in an organic solvent.
nd. Eng. Chem. 51 147 1959,
JP-B-37-5599), a melt polymerization method in which a divalent carboxylic acid and a dihydric phenol are heated in the presence of acetic anhydride, and a divalent carboxylic acid and a dihydric phenol are heated in the presence of diallyl carbonate. Melt polymerization method
-26299), an interfacial polymerization method of mixing a divalent carboxylic acid halide dissolved in an organic solvent incompatible with water and a divalent phenol dissolved in an aqueous alkaline solution (WM EARCKSON J. Poly). .Sc
i. XL399, 1959, Japanese Patent Publication No. 40-1959), etc., and the polyarylate of the present invention can be produced by the above-mentioned known methods, but interfacial polymerization is particularly preferably employed. The interfacial polymerization method is faster in reaction than the solution polymerization method, so that the hydrolysis of the acid halide can be minimized, which is advantageous when a polymer having a low carboxyl number as in the present invention is obtained. is there.

The production method by the interfacial polymerization method will be described in more detail. An aqueous alkali solution of dihydric phenol is prepared,
Subsequently, a polymerization catalyst, for example, tertiary amines such as trimethylamine, triethylamine, tri-n-butylamine, trihexylamine, tridodecylamine, N, N-dimethylcyclohexylamine, pyridine, quinoline and dimethylaniline, and trimethylbenzylammonium halide Quaternary ammonium salts such as tributylbenzylammonium halide, triethylbenzylammonium halide, tetrabutylammonium halide, trimethylbenzylphosphonium halide, tributylbenzylphosphonium halide, triethylbenzylphosphonium halide, tetrabutylphosphonium halide, triphenylbenzylphosphonium halide, tetra Quaternary phosphonium salts such as phenylphosphonium halide,
18-crown-6,18-benzocrown-6,18
-Add a crown ether such as dibenzocrown-6, 15-crown-5. As the polymerization catalyst, tributylbenzylammonium halide, tetrabutylammonium halide, and tetrabutylphosphonium halide are particularly preferable since the reaction rate is high and the hydrolysis of acid halide is minimized.

On the other hand, a solvent which is insoluble in water and dissolves polyarylate, for example, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride, chlorobenzene, 1,1,2,2-tetrachloroethane , 1,1,
A solution obtained by dissolving a divalent carboxylic acid halide in a chlorine-based solvent such as 1-trichloroethane, o-, m-, or p-dichlorobenzene, or an aromatic hydrocarbon such as toluene, benzene, or xylene is used as the alkali solution. Mix. The polyarylate of the present invention can be obtained by carrying out the reaction while stirring at a temperature of 25 ° C. or lower for 1 hour to 5 hours.
Examples of the alkali that can be used here include sodium hydroxide and potassium hydroxide.

The molecular weight of the polyarylate can be controlled by the amount of the terminal blocking agent described above.
Inherent viscosity is a value directly related to the molecular weight of the polymer. Using tetrachloroethane as a solvent for viscosity measurement, the inherent viscosity was measured at 25 ° C. in a 1 g / dl solution. The inherent viscosity is preferably in the range of 0.25 to 1.20, and more preferably 0.35 to 1.20.
00. If the inherent viscosity is less than 0.25, the mechanical properties as a polymer tend to decrease, while if it exceeds 1.20, the molding processing properties at the time of melting and the solubility in a solvent tend to decrease, which is not preferable.

The carboxyl number of the polyarylate of the present invention is 20 mol / ton or less, preferably 15 mol / ton or less.
Mol / ton or less. If it exceeds 20 mol / ton, electric characteristics may be deteriorated, which is not preferable. The method for measuring the carboxyl number of the polyarylate of the present invention comprises:
A known method can be adopted. Specifically, it can be measured by dissolving polyarylate in a mixed solvent of benzyl alcohol and chloroform, and performing a neutralization titration with an aqueous benzyl alcohol solution of KOH.

The polyarylate of the present invention is substantially amorphous and has high solubility in solvents, especially methylene chloride. The solubility of polyarylate in methylene chloride can be confirmed by various methods, but the simplest method is to carry out interfacial polymerization using methylene chloride as a solvent. When the solubility is good, the methylene chloride solution of the polyarylate after the interfacial polymerization is a homogeneous solution, but when the solubility is bad, the polymer precipitates after the start of the polymerization, and the polymer precipitates after the polymerization.

The stability of the coating solution (polymer solution) can be evaluated by dissolving the polymer in a solvent at a concentration used when used as a coating solution, and allowing the polymer to stand at room temperature. In the case of poor, the solution becomes turbid or gels with the passage of time even if it is uniformly dissolved. In the present invention, the polyarylate is dissolved in methylene chloride at a concentration of 10% by weight or more, preferably 15 to 20% by weight, and left at room temperature to obtain good stability.

Further, whether or not it is amorphous may be confirmed by a known method such as differential scanning calorimetry (DSC) or dynamic viscoelasticity measurement to determine whether or not a melting point exists. Various antioxidants such as hindered phenol-based, hindered amine-based, thioether-based, and phosphorus-based agents can be added to the polyarylate of the present invention as long as the properties are not impaired.

The polyarylate of the present invention can be applied as a melt molded product or an extruded film, or as a binder resin or a solvent cast film dissolved in a solvent, particularly in the field of electronic materials.

[0034]

EXAMPLES Next, the present invention will be described in detail with reference to Examples, Reference Examples and Comparative Examples, but the present invention is not limited to these, and various modifications and changes can be made without departing from the spirit of the present invention. Application is possible.

Example 1 100 parts by weight of 2,2-bis (3-methyl-4-hydroxyphenyl) propane was placed in a reaction vessel equipped with a stirrer.
3,3'-dimethyl-4,4'-biphenol 35.8
Parts by weight, 2.5 parts by weight of p-tert-butylphenol, 54.7 parts by weight of sodium hydroxide, and 1.3 parts by weight of tri-n-butylbenzylammonium chloride were dissolved in 3450 parts by weight of water (aqueous phase). . Separately, 115 parts by weight of a terephthalic acid chloride / isophthalic acid chloride = 1/1 mixture was dissolved in 1560 parts by weight of methylene chloride (organic phase). This organic phase was added to the previously prepared aqueous phase under vigorous stirring, and a polymerization reaction was carried out for 3 hours.
Thereafter, 50 parts by weight of acetic acid was added to stop the reaction, the aqueous phase and the organic phase were separated, and water washing was repeated until the organic phase became neutral, and the organic phase was added to methanol to precipitate the polymer. Was. The polymer was separated and dried to obtain a polyarylate containing 3,3′-dimethyl-4,4′-biphenol units in an amount of 30 mol%.

Examples 2 to 11 and Comparative Examples 1 to 6 Polyarylates were produced in the same manner as in Example 1 except that the preparation of the dihydric phenol was changed. Table 1 shows the charging conditions of the dihydric phenol.

Comparative Example 7 The procedure of Example 1 was repeated, except that 1.3 parts by weight of trimethylbenzylammonium chloride was used instead of 1.3 parts by weight of tributylbenzylammonium chloride.

Evaluation of Polyarylate The physical properties of the polyarylate synthesized as described above were evaluated. Table 2 shows the results. The following evaluation method was used.

1) Inherent Viscosity Using 1,1,2,2-tetrachloroethane as a solvent, the temperature was 25 ° C. and the concentration was 1 g / dl.

2) Carboxyl number 0.15 g of polyarylate was precisely weighed in a test tube, and dissolved by heating in 5 ml of benzyl alcohol. Chloroform 1
After mixing 0 ml with a benzyl alcohol solution of polyarylate, phenol red was added as an indicator, and neutralization titration was performed with a 0.1 N-KOH benzyl alcohol solution with stirring to obtain a carboxyl number.

3) Solubility in methylene chloride 10 g of the polyarylate obtained in each of Examples and Comparative Examples was dissolved in 90 g of methylene chloride. The state of dissolution was visually determined.

4) Stability of coating liquid 15 g of the polyarylate obtained in each of Examples and Comparative Examples was dissolved in 85 g of methylene chloride and sealed, and the mixture was sealed at room temperature (25 ° C.).
Left. In this state, it was visually determined whether or not gelation occurred.

5) Dielectric constant and dielectric loss tangent A solvent cast film having a thickness of 50 μm was prepared from a solution of polyarylate in methylene chloride. Using this film as a test piece, measurement was performed at 1 MHz according to ASTM D-150.

6) Dielectric breakdown voltage The measurement was performed in accordance with ASTM D149 by using the same polyarylate film having a thickness of 50 μm as in 5).

[0045]

[Table 1]

[0046]

[Table 2]

From the above results, the following became clear. 1) From a comparison between Comparative Examples 1, 2 and 5, and Examples 1 to 11, the polyarylate of the present invention is excellent in electrical characteristics because a specific biphenol derivative is copolymerized.

2) Comparative Examples 3, 4 and 6 and Examples 1-1
From the comparison of 3, the polyarylate of the present invention has good solubility in solvents and stability of the coating solution.

3) From the comparison between Comparative Example 7 and Example 3, since the polyarylate of the present invention has a low carboxyl number, it has excellent electrical properties.

[0050]

The polyarylate of the present invention has excellent electrical properties, is soluble in a solvent, and has excellent stability of a coating solution. Therefore, it can be easily formed into a film as well as a molded product, and it can be applied to dielectric films such as electrical equipment, motors, generators, insulating materials such as interphase insulation, transformers, electric wire coatings, capacitors, etc. And also
As a binder resin for an electrophotographic photosensitive member, a binder resin for an electrophotographic carrier, and a surface coating material, it can be suitably used for electronic material applications.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Hayase 23, Uji Kozakura, Uji-city, Kyoto, Japan Unitika, Ltd. In-house (72) Inventor Yashiro Ito 23 Uji Kozakura, Uji City, Kyoto Pref.

Claims (1)

[Claims] 1. A polyarylate comprising a dihydric phenol and an aromatic dicarboxylic acid, wherein the dihydric phenol is represented by the following general formula (1): Wherein, R ₁ to R ₈ represent each independently a hydrogen atom, a halogen atom, a group selected from among hydrocarbon groups and alkoxy groups having 1 to 4 carbon atoms having 1 to 4 carbon atoms, R ₁ ~ R ₈
At least one of them represents a substituent other than a hydrogen atom. And the terminal carboxyl number is not more than 20 mol / ton, and the solubility in methylene chloride is not less than 10% by weight. A polyarylate characterized by having.