JP3053249B2 - Production method of polycarbonate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high molecular weight polycarbonate obtained by polycondensing a dihydric phenol and a carbonic acid diester in the presence of unsubstituted or substituted phenylacetic acid.

[0002]

BACKGROUND OF THE INVENTION The high molecular weight polycarbonates of the present invention have a wide variety of uses, especially for injection molding or as glass sheets in place of window glass. General-purpose engineering thermoplastics.

[0003] The interfacial polycondensation method is generally effective for the production of polycarbonate, but has disadvantages such as the use of toxic phosgene and the generation of chloride ions in the polycarbonate.

[0004] In order to eliminate these drawbacks, the production of polycarbonate by an interfacial polycondensation reaction with a special dihydric phenol using liquid trichloromethyl chloroformate, which is a dimer of phosgene, instead of toxic phosgene is a special feature. It is disclosed in JP-A-63-182336.

However, there is only description of 9,9-bis (4-hydroxyphenyl) fluorenes, which are special dihydric phenols. In addition, triphosgene is used in place of toxic phosgene to give 2,2-bis (4
-Hydroxyphenyl) propane is described in Angew. Chem. (Angevante,
Hemy) 99 . 922 (1987), but a reaction mechanism for generating phosgene has also been proposed.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have prepared a diester of carbonic acid and a dihydric phenol in the presence of unsubstituted or substituted phenylacetic acid as a compound for forming a carbonate bond.
Polycondensation has led to the finding that high-molecular-weight polycarbonates which do not use toxic phosgene and are essentially free of chloride ions have been obtained.

The present invention provides 1) a method for producing a polycarbonate, which comprises polycondensing a dihydric phenol with a carbonic acid diester in the presence of a catalyst selected from unsubstituted or substituted phenylacetic acids represented by the following chemical formula 1.

[0008] 2) The method for producing a polycarbonate according to claim 1, wherein the dihydric phenol is represented by Chemical Formula 2, Chemical Formula 3, Chemical Formula 4, or Chemical Formula 5. 3) The method for producing the polycarbonate copolymer according to the above 1) or 2).

Representative examples of the unsubstituted or substituted phenylacetic acid which can be used in the present invention include phenylacetic acid, p-methoxyphenylacetic acid, p-pentoxyphenylacetic acid, p-nitrophenylacetic acid, 1-phenylpropionic acid, -Phenylacetic acid, diphenylacetic acid, triphenylacetic acid, 1-
Phenyl-1-methylpropionic acid, 1-phenyl-1
-Phthylpropionic acid, 1-phenyl-1-pentylbutyric acid, 1- (p-methoxyphenyl) -1-methylpropionic acid and the like.

[0010] Representative examples of dihydric phenols include:
The following compounds are mentioned. As bisphenols classified into Chemical Formula 2, 2,2-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxyphenyl) butane, 2,2-bis- (4-hydroxyphenyl)- 4-methylpentane, 2,2-bis- (4-hydroxyphenyl) octane, 4,4'-dihydroxy-2,2,2-triphenylethane, 2,2-bis-
(3,5-dibromo-4-hydroxyphenyl) propane and the like.

As the dihydric phenols classified into the chemical formula 3, 2,2-bis- (4-hydroxy-3-methylphenyl) propane and 2,2-bis- (4-hydroxy-3
-Isopropylphenyl) propane, 2,2-bis-
(4-hydroxy-3-sec.butylphenyl) propane, 2,2-bis- (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxy-3-tert-butyl) Phenyl) propane and the like.

As the dihydric phenol classified in the chemical formula 4, 1,1'-bis- (4-hydroxyphenyl) -p
-Diisopropylbenzene, 1,1'-bis- (4-hydroxyphenyl) -m-diisopropylbenzene and the like.

As the dihydric phenol classified in the chemical formula 5, there is 1,1'-bis- (4-hydroxyphenyl) cyclohexane. Further, the chemical formulas 2, 3, 4,
It is also possible to produce a copolymerized polycarbonate in which two or three or more dihydric phenols selected from 5 are combined.

The process of the present invention is carried out by a polycondensation reaction of a dihydric phenol such as bisphenol A with a carbonic acid diester using a catalyst selected from unsubstituted or substituted phenylacetic acids.

The temperature at which this reaction proceeds ranges from above 100 ° C. to about 300 ° C. Preferably it is in the range of 130 ° C to 280 ° C. If the temperature is lower than 130 ° C., the reaction rate becomes slow, and if it exceeds 300 ° C., a side reaction tends to occur.

[0016] unsubstituted or substituted phenyl acetic acid is used as the catalyst, it requires a ^{10 -5} mol to ^{10 -1} mol with respect to the dihydric phenol present in the reaction system, 10 preferably from ^{10 -2} mol ^{- 4} moles. If the amount is less than 10 ^-5 mol, the catalytic action is small, and the polymerization rate of the polycarbonate is slow. If the amount is 10 ^-1 mol or more, the rate of remaining in the polycarbonate produced as a catalyst increases, leading to a decrease in the physical properties of the polycarbonate.

In addition, a compound containing an alkali metal or an alkaline earth metal and a T
Compounds containing i, Zn, Sn, Cd, Sb, Mn, Ge and the like can be used in combination, but in particular, alkali metals or alkaline earth metals are included in the polycarbonate because they have a bad influence on the hue of the polycarbonate. The concentration of the alkali metal or alkaline earth metal needs to be 10 ppm or less. Further, the concentration of hydrolyzable chloride ions also needs to be 5 ppm or less because it has a bad influence on the hue of the polycarbonate.

The required amount of the carbonic acid diester is equivalent to that of the dihydric phenol present in the reaction system. Generally, in order to produce a high molecular polycarbonate, one mole of a carbonate compound and one mole of a dihydric phenol must react. When bisphenyl carbonate is used, 2 moles of phenol are formed by the reaction. These two moles of phenol are distilled out of the reaction system.

However, the bisphenyl carbonate charged so that the concentration of terminal hydroxyl groups to all the terminal groups of the polycarbonate is 30 mol% or less requires a molar number of 1.005 to 1.5 times the molar number of the dihydric phenol. And Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

[0020]

Example 1 2,2-bis (4-hydroxyphenyl)
22.8 g (0.1 mol) of propane and 0.1% of phenylacetic acid.
027 mg (2 × 10 ⁻⁴ mol) and 21.4 g (0.1 mol) of bisphenyl carbonate were added, and the mixture was added with nitrogen under nitrogen.
After stirring at 1 ° C. for 1 hour, the temperature was raised while gradually reducing the pressure, and finally the phenol produced by a polycondensation reaction at 0.1 ^Torr and 270 ° C. for 1 hour was distilled off to obtain a colorless and transparent polycarbonate. When the viscosity average molecular weight is measured, v =
It was 26,000. The glass transition temperature is 151
° C. The viscosity-average molecular weight is measured by measuring the intrinsic viscosity [η] of the methylene chloride solution at 20 ° C. using an Ubbelohde viscometer, and using the following equation to calculate the viscosity-average molecular weight v
Was calculated.

[0021]

(Equation 1)

[0022]

Example 2 0.018 mg of p-nitrophenylacetic acid was used in place of phenylacetic acid under exactly the same conditions as in Example 1.
(1 × 10 ⁻⁴ mol) and stirred under nitrogen for 2 hours.
A polycondensation reaction was performed in the same manner as in Example 1 to obtain a colorless and transparent polycarbonate. When the viscosity average molecular weight was measured, it was v = 27,000. The glass transition temperature is 1
It was 50 ° C.

[0023]

Example 3 2,2-bis (4-hydroxyphenyl)
11.4 g (50 mol%) of propane, 2,2-bis (4
-Hydroxy-3-tert-butylphenyl) propane 17.0 g (50 mol%), phenylacetic acid 0.027
mg (2 × 10 ⁻⁴ mol) was stirred under nitrogen for 2 hours, and then subjected to a polycondensation reaction in the same manner as in Example 1 to obtain a colorless and transparent polycarbonate. This polycarbonate has a viscosity average molecular weight v = 25,500 and a glass transition temperature of 127 ° C.
Met.

[0024]

COMPARATIVE EXAMPLE The same treatment as in Example 1 was carried out except that pyridine was used instead of phenylacetic acid, and the viscosity average molecular weight of the obtained polycarbonate was v = 4,000.
0, which was a low molecular weight which was not suitable for practical use although it was in the form of polycarbonate.

[0025]

By using unsubstituted or substituted phenylacetic acid as a catalyst, a high molecular weight, colorless and transparent polycarbonate substantially free of chloride ions can be obtained without using toxic phosgene.

Claims (3)

(57) [Claims] 1. A process for producing a polycarbonate, comprising polycondensing a dihydric phenol with a carbonic acid diester in the presence of a catalyst selected from unsubstituted or substituted phenylacetic acids represented by the chemical formula 1. Embedded image (R ₁ is hydrogen or an alkoxyl group or nitro group having 1 to 5 carbon atoms, R ₂ and R ₃ are hydrogen or an alkyl group or phenyl group having 1 to 5 carbon atoms) 2. The method for producing a polycarbonate according to claim 1, wherein the dihydric phenol is represented by Chemical Formula 2, Chemical Formula 3, Chemical Formula 4, or Chemical Formula 5. Embedded image Embedded image Embedded image Embedded image (R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen or a linear or branched alkyl group having 1 to 8 carbon atoms or a phenyl group, X is a halogen atom, and n = 0 to 4, m = 1-4) 3. The method for producing a polycarbonate copolymer according to claim 1 or 2.