JPH0687954A - Production of polycarbonate - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate polymer having a high mol.wt. without employing toxic phosgene by melt-polycondensing a dihydric phenol with a carbonic diester in the presence of a catalyst such as a basic nitrogen compound and a catalyst such as (substituted)phenylacetic acid. CONSTITUTION:A dihydric phenol [e.g. 2,2-bis(4-hydroxyphenyl)propane] and a carbonic diester (e.g. diphenyl carbonate) are subjected to a melt- polycondensation reaction in the presence of a catalyst such as a nitrogen compound (e.g. 2-methylimidazole) and a catalyst such as a non-substituted or substituted phenylacetic acid of the formula (R1 is H, 1-5C alkoxy, nitro; R2, R3 are H, 1-5C alkyl, phenyl) (e.g. phenylacetic acid) to produce the objective high mol.wt. polycarbonate without using toxic phosgene, the melt- polycondensation reaction comprising stirring the raw materials at 180 deg.C in a nitrogen atmosphere for 1hr, subjecting the reaction product to the rise in temperature, while gradually lowering the pressure, and finally polycondensing the reaction product at 270 deg.C under 0.1Torr for 1hr, while distilling off the by-produced phenol.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a process for producing a high molecular weight polycarbonate obtained by polycondensing a dihydric phenol and a carbonic acid diester in the presence of a catalyst selected from basic nitrogen compounds and unsubstituted or substituted phenylacetic acid. It is about.

[0002]

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

Although the interfacial polycondensation method is generally effective in the production of polycarbonate, it has drawbacks such as the use of toxic phosgene and chlorine ion remaining in the polycarbonate.

In order to eliminate these drawbacks, it is a special feature to produce a 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. It is disclosed in Kaishoku 63-182336.

However, there is only a description of 9,9-bis (4-hydroxyphenyl) fluorene which is a special dihydric phenol. Also, using triphosgene instead of toxic phosgene, 2,2-bis (4
-Hydroxyphenyl) propane to obtain a polycarbonate is described in Angew. Chem. (Angevante,
Hemy) 99 . 922 (1987), a reaction mechanism for generating phosgene is also proposed.

Further, Japanese Patent Application Laid-Open No. 60-51719 proposes a method for producing a polycarbonate using a catalyst composed of a combination of a nitrogen-containing basic compound and a boron compound. Although a light-colored polycarbonate can be obtained, this catalyst has a problem that the polymerization activity is low.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention, by polycondensing a carbonic acid diester and a dihydric phenol as a compound which forms a carbonate bond in the presence of a basic nitrogen compound and an unsubstituted or substituted phenylacetic acid, It has been found that high molecular weight polycarbonates are obtained which are free of toxic phosgene and essentially free of chloride ions.

The present invention comprises 1) polycondensing a dihydric phenol with a carbonic acid diester in the presence of a catalyst selected from a basic nitrogen compound and a catalyst selected from an unsubstituted or substituted phenylacetic acid represented by Formula 1. A method for producing a polycarbonate characterized by the following.

2) A method for producing a polycarbonate according to 1), wherein the dihydric phenol is represented by Chemical Formula 2, Chemical Formula 3, Chemical Formula 4, and Chemical Formula 5. 3) The method for producing a polycarbonate copolymer described in 1) or 2) above.

Typical examples of the basic nitrogen compound which can be used in the present invention include 4-dimethylaminopyridine and 4- (4
-Methylpyrrolidinyl) pyridine, 4-diethylaminopyridine, 4-pyrrolidinopyridine, 4-aminopyridine, 2-aminopyridine, 2-hydroxypyridine, 2
-Methoxypyridine, 4-methoxypyridine, 4-hydroxypyridine, 2-dimethylaminoimidazole, 2
-Methoxyimidazole, 2-mercaptoimidazole, 2-aminopyridineaminoquinoline, benzimidazole, imidazole, 2-methylimidazole, 4-
Methylimidazole, diazabicyclooctane (DAB
CO), 1,8-diaza-bicyclo [5,4,0] -7
-Undecene (DBU) and the like.

Representative examples of unsubstituted or substituted phenylacetic acid include phenylacetic acid, p-methoxyphenylacetic acid, p
-Pentoxyphenylacetic acid, p-Nitrophenylacetic acid,
1-phenylpropionic acid, 1-phenylacetic acid, diphenylacetic acid, triphenylacetic acid, 1-phenyl-1-methylpropionic acid, 1-phenyl-1-futylpropionic acid, 1-phenyl-1-pentylbutyric acid, 1- (P-Methoxyphenyl) -1-methylpropionic acid and the like can be mentioned.

Further, as a representative example of the dihydric phenol,
The following compounds may be mentioned. As the bisphenol classified into the 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 can be mentioned.

2,2-bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxy-3) as the dihydric phenol classified in the chemical formula 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 into 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, 1,1-bis- (4-hydroxyphenyl) cyclohexane can be mentioned. Furthermore, the chemical formulas 2, 3, 4, 5
It is also possible to produce a copolycarbonate in which two or more dihydric phenols selected from the above are combined.

The process of the present invention comprises polycondensing a dihydric phenol such as bisphenol A with a carbonic acid diester using a catalyst selected from basic nitrogen compounds and a catalyst selected from unsubstituted or substituted phenylacetic acid. Carried out by

The temperature at which this reaction proceeds is in the range of 100 ° C or higher to about 300 ° C. It is preferably in the range of 130 ° C to 280 ° C. If it is lower than 130 ° C, the reaction rate becomes slow, and if it exceeds 300 ° C, side reactions are likely to occur.

The basic nitrogen compound used as a catalyst, in particular electron-donating amine compounds, requires a 10 ^-5 mol to 10 ^-1 mol with respect to the dihydric phenol present in the reaction system, preferably 10 ^- It is from ² mol to 10 ⁻⁴ mol. Since the rate remaining in the polycarbonate produced as a catalyst When it is 10 ^-5 is less than the molar the polymerization rate of catalysis is small polycarbonate becomes slow 10 ^-1 mole or higher leads to deterioration of physical properties of the polycarbonate.

Further, the unsubstituted or substituted phenylacetic acid used as the combined catalyst requires 10 ^-1 to 10 ^-5 mol, preferably 10 ^-2 mol, relative to the dihydric phenol present in the reaction system. To 10 ⁻⁴ mol. If it is less than 10 ^-5 mol, the catalytic action is small and the polymerization degree of the polycarbonate cannot be reached. If it is 10 ^-1 mol or more, the residual rate in the polycarbonate formed as a catalyst becomes high, and the physical properties of the polycarbonate are deteriorated.

Further, as the catalyst of the third component, a compound containing an alkali metal or an alkaline earth metal, which is a conventionally known transesterification catalyst, or Ti, Zn, Sn, Cd, Sb,
It is also possible to use a compound containing Mn, Ge or the like together. In particular, since the alkali metal or alkaline earth metal adversely affects the hue of the polycarbonate, the concentration of the alkali metal or alkaline earth metal contained in the polycarbonate needs to be 10 ppm or less. Further, the concentration of hydrolyzable chlorine ions also adversely affects the hue of the polycarbonate, so it is necessary to be 5 ppm or less.

The required amount of the carbonic acid diester is the same as that of the dihydric phenol present in the reaction system. In general, 1 mol of a carbonate compound and 1 mol of a dihydric phenol must react in order to produce a high-molecular polycarbonate. With bisphenyl carbonate, 2 moles of phenol are produced by the reaction. These 2 moles of phenol are distilled out of the reaction system.

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

[0023]

Example 1 2,2-bis (4-hydroxyphenyl)
Propane 22.8 g (0.1 mol), 2-methylimidazole 0.164 g (2 × 10 ⁻² mol), phenylacetic acid 0.027 mg (2 × 10 ⁻⁴ mol), and bisphenyl carbonate 21.4 g (0. (1 mol) and stirred under nitrogen at 180 ° C. for 1 hour, and then gradually heated under reduced pressure to allow polycondensation reaction at 0.1 ^Torr , 270 ° C. for 1 hour to distill off the produced phenol. It was. The glass transition temperature was 149 ° 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,

[0024]

[Equation 1]

[0025]

Example 2 Under exactly the same conditions as in Example 1, 0.0122 g (1 × 10 ⁻⁴ mol) of 4-dimethylaminopyridine was added in place of 2-methylimidazole, and under nitrogen,
After stirring for 2 hours, a polycondensation reaction was performed in the same manner as in Example 1 to obtain a colorless transparent polycarbonate. When measuring the viscosity average molecular weight

[0026]

Example 3 2,2-bis (4-hydroxyphenyl)
Propane 11.4 g (50 mol%), 2,2-bis (4
-Hydroxy-3-tert-butylphenyl) propane 17.0 g (50 mol%), 4-dimethylaminopyridine 0.0122 g (1 x 10 ^-4 mol) and phenylacetic acid 0.027 g (2 x 10 ^-4 mol). After stirring under nitrogen for 2 hours, a polycondensation reaction was carried out in the same manner as in Example 1 to obtain a colorless transparent polycarbonate. This port

[0027]

Comparative Example Under exactly the same conditions as in Example 3, pyridine was used in place of 4-dimethylaminopyridine, and acetic acid of 0.
006 g (1 × 10 ⁻⁴ mol) was added and the same treatment was carried out. However, the low molecular weight was not suitable for practical use.

[0028]

EFFECTS OF THE INVENTION By using as a catalyst selected from a basic nitrogen compound and an unsubstituted or substituted phenylacetic acid, a colorless and transparent polycarbonate having substantially no chlorine ion and a high molecular weight is obtained without using toxic phosgene. I was able to.

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[Procedure amendment]

[Submission date] September 16, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Added

[Correction content]

Title: Method for producing polycarbonate

Claims (3)

[Claims] 1. A polycondensation of a dihydric phenol and a carbonic acid diester in the presence of a catalyst selected from a basic nitrogen compound and a catalyst selected from an unsubstituted or substituted phenylacetic acid represented by the chemical formula 1. Method for producing polycarbonate. [Chemical 1] (R ₁ is hydrogen or an alkoxyl group having 1 to 5 carbon atoms or a nitro group, and R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 5 carbon atoms or a phenyl group) 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, and Chemical Formula 5. [Chemical 2] [Chemical 3] [Chemical 4] [Chemical 5] (R ₁ , R ₂ , R ₃ and R ₄ are hydrogen or an alkyl group having a straight or branched chain having 1 to 8 carbon atoms, or a phenyl group, and X is a halogen atom, n = 0 to 4, m = 1-4) 3. A method for producing the polycarbonate copolymer according to claim 1 or 2.