JP2904299B2 - Production method of polycarbonate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is to melt-polycondensate a divalent hydroxy compound with a bisaryl carbonate by a transesterification method in the presence of a transesterification catalyst, and furthermore, a specific phosphite The present invention relates to a method for producing a high-molecular-weight polycarbonate having excellent thermal stability, hue, and hydrolysis stability obtained by inactivating a catalyst residue by adding a compound.

(Prior Art and Problems to be Solved by the Invention) High-molecular-weight polycarbonates having excellent heat stability, hue, and hydrolysis stability have a wide range of applications, particularly for injection molding or as glass sheets instead of window glasses.
General-purpose engineering thermoplastics. The production of polycarbonate has been roughly classified into two methods: an interfacial polycondensation method (phosgene method) and a transesterification method. 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 produced. In order to eliminate these drawbacks, it has been proposed to produce 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. -182336. However, it is a special dihydric phenol
There is only description of 9,9-bis (4-hydroxyphenyl) fluorenes. Further, to obtain a polycarbonate from 2,2-bis (4-hydroxyphenyl) propane with triphosgene instead of toxic phosgene Angew. (Angewandte, Chemie) 99.922 (1
987), a reaction mechanism for generating phosgene has also been proposed. Also, many proposals have been made on how to make the reaction conditions mild to obtain a high-molecular-weight polycarbonate having a good hue when a high-molecular-weight polycarbonate is produced by a transesterification method.

For example, in Japanese Patent Publication No. 47-14742, an initial condensate is formed from an aromatic dioxy compound and a bisaryl carbonate in the presence of a chlorinated catalyst, and then a post-condensation reaction is performed on the initial condensate in the presence of a quaternary ammonium compound. It shows that a polycarbonate having excellent heat stability and hue can be obtained. In JP-B-47-14743, a polycarbonate having a good hue is similarly obtained from an aromatic dioxy compound and bisallyl carbonate by using a quaternary ammonium-hydroloxide as a transesterification catalyst. According to US Pat. No. 4,363,905, a high-molecular-weight polycarbonate having a good hue is obtained by using a phase transfer catalyst in combination with a basic catalyst under basic reaction conditions including a basic catalyst. Or tetraethylphosphonium hydroxide.

However, even if the transesterification reaction is carried out using the above-mentioned transesterification catalyst, deterioration of the hue cannot be avoided if the polycondensation time is long in order to obtain a high molecular weight polycarbonate. Further, the catalyst residue is not deactivated, and the heat resistance and the hydrolysis resistance are essentially insufficient as shown in Comparative Examples.

(Means for Solving the Problems) The present inventors melt-polycondensate a bisaryl carbonate and a divalent hydroxy compound as compounds for forming a carbonate bond by a transesterification method in the presence of a transesterification catalyst to form a phosphite compound. The fact that the addition makes it possible to obtain a high-molecular-weight polycarbonate excellent in heat stability, hue, and hydrolysis stability by not using toxic phosgene, containing essentially no chloride ions, and deactivating the catalyst residue. I came to find.

The present invention relates to (1) a method in which 2
Engineering plastic material characterized by adding a phosphite compound represented by the following structural formula (I) to a polycarbonate obtained by melt-polycondensation of a bivalent hydroxy compound and a bisaryl carbonate by a transesterification reaction. A method for producing a polycarbonate for general engineering plastics, wherein the hydrolysis resistance of the polycarbonate for engineering plastics materials is 90% or more, and after 30 days under conditions of 100% RH (relative humidity), the retention of the molecular weight to the initial molecular weight is 86% or more. The heat resistance is in a nitrogen gas stream, at a heating rate of 10 ° C./min, using a differential thermogravimetric analyzer, the decomposition starting temperature is 426 ° C. or more, the temperature at which the weight loss reaches 5% is 465 ° C. or more, General engineering with improved heat resistance and hydrolysis resistance when the temperature at which the weight loss reaches 10% is 478 ° C or higher
Manufacturing method of polycarbonate for plastic materials.

(2) In the polycondensation step, the addition of the phosphite compound represented by the structural formula (I) is performed based on the relative viscosity of the produced polymer estimated from the stirring torque (polymer concentration: 0.5 g / 100 m 2).
2. The production of the polycarbonate resin for general engineering plastic materials according to claim 1, wherein the measurement is carried out when (measured value under the condition of solvent: methylene chloride, sample temperature 20 ° C.) becomes 1.17 or more. The hydrolysis resistance of the polycarbonate for general engineering plastic materials is 90 ° C., 100% RH (relative humidity) after 30 days, the retention of the molecular weight to the initial molecular weight is 86% or more, Heating rate in nitrogen stream
At a temperature of 10 ° C / min, with a differential thermogravimetric analyzer, the decomposition onset temperature is 426 ° C or more, the temperature at which the weight loss reaches 5% is 465 ° C or more, and the temperature at which the weight loss reaches 10% is 478 ° C or more General engineering with improved heat resistance and hydrolysis resistance
Manufacturing method of polycarbonate for plastic materials.

Representative examples of the transesterification catalyst that can be used in the present invention include (a) lithium borohydride, sodium borohydride, potassium borohydride, rubidium borohydride, cesium borohydride similar to a catalyst containing a metal,
Beryllium borohydride, magnesium borohydride,
Calcium borohydride, strontium borohydride, barium borohydride, aluminum borohydride, titanium borohydride, tin borohydride, germanium borohydride, tetraphenoxylinium, tetraphenoxy sodium, tetraphenoxy potassium, tetraphenoxy Rubidium, tetraphenoxycesium, sodium thiosulfate, beryllium oxide, magnesium oxide, tin (IV) oxide, dibutyltin oxide,
Beryllium hydroxide, magnesium hydroxide, germanium hydroxide, beryllium acetate, magnesium acetate, tin (IV) acetate, germanium acetate, lithium carbonate, sodium carbonate, potassium carbonate, beryllium carbonate, magnesium carbonate, tin (IV) carbonate, germanium carbonate , Tin nitrate (I
V), germanium nitrate, antimony trioxide, bismuth trimethycarboxylate, and the like. (B) N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 4-pyridinopyridine, 4- (5-noryl) -pyridine, 4-aminopyridine, 2-amino similar to an electron-donating amine compound Pyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 4-hydroxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, 2-mercaptoimidazole, 2-aminopyridine, aminoquinoline, imidazole, 2- Methyl imidazole, 4-methyl imidazole, diazabicyclooctane (DABCO) and the like can be mentioned. (C) or the above-mentioned electron-donating amine compounds such as carbonic acid, acetic acid, formic acid, nitric acid, nitrous acid, oxalic acid, boronic acid, and hydrofluoric acid. (D) triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tri-o-dimethoxyphenylphosphine, tri-p-tolylphosphine, similar to an electron-donating phosphorus compound; Tri-o-
Tolyl phosphine, tributyl phosphite, triphenyl phosphite, tri-p-tolyl phosphite, tri-o-tolyl phosphite and the like can be mentioned. (E) As a borane complex, a complex of borane and the following compounds, namely, ammonia, dimethylamine, trimethylamine, triethylamine, t-butylamine, dimethylaniline, pyridine, dimethylaminopyridine,
Complexes with morpholine, piperazine, pyrrole, tetrahydrofuran, dimethylsulfide, tri-n-butylphosphine, triphenylphosphine, triphenylphosphite and the like can be mentioned.

In addition, typical examples of the divalent hydroxy compound include the following compounds. 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, 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 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-butylphenyl) propane, 1,1 '
-Bis- (4-hydroxyphenyl) -p-diisopropylbenzene, 1,1'-bis- (4-hydroxyphenyl) -m-diisopropylbenzene, 1,1-bis- (4-
(Hydroxyphenyl) cyclohexane and the like.
Further, two or three or more selected from the above
It is also possible to produce a copolymerized polycarbonate in which a divalent hydroxy compound is combined.

Further, the structural formula (I) used in the present invention is preferably tris (2,4-di-t-butylphenyl phosphite). Representative examples of bisaryl carbonates include diphenyl carbonate, bis (2,4-dichlorophenyl) carbonate, bis (2,4,6-trichlorophenyl) carbonate, bis (2-cyanophenyl) carbonate, and bis (2-cyanophenyl) carbonate. Bisaryl carbonates having unsubstituted and nuclear substituents such as (o-nitrophenyl) carbonate, ditolyl carbonate and the like can be mentioned.

The process of the present invention is carried out by subjecting a divalent hydroxy compound such as bisphenol A to a melt polycondensation reaction with a bisaryl carbonate by a transesterification method using a catalyst selected from a transesterification catalyst.

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.

The transesterification catalyst used as the catalyst is 10 ^-1 mol to 10 ^-5 mol based on the divalent hydroxy compound present in the reaction system.
A mole is required, but preferably from 10 ^-2 to 10 ^-4 mole. When the amount is less than 10 ^-5 mol, the catalytic action is small, and the polymerization rate of the polycarbonate is slow. When the amount is 10 ^-1 mol or more, the rate of remaining in the polycarbonate produced as a catalyst becomes high, which leads to deterioration of the physical properties of the polycarbonate. At any point, tris (2,4-di-t-butylphenyl phosphite) is added to the polycarbonate, with the amount of phosphite compound added being from 0.01% to 0.5% by weight, based on the total polymer. , Preferably from 0.03% to 0.3% by weight. If the addition amount is 0.03% by weight or less, it has no effect as a stabilizer and adversely affects the heat resistance and hydrolysis resistance of the polycarbonate. Also, 0.3
Exceeding the weight percent adversely affects the mechanical properties of the polycarbonate.

The polymer thus obtained is used as a general engineering plastic material, but is particularly exposed to high-temperature and high-humidity conditions such as outdoor lighting equipment, window glass, outdoor applications such as fences, microwave ovens, tableware, tanks, and transport pipes. Suitable as a material for use.

In addition, the present invention is applicable to heat-sensitive elements such as electric blankets and carpets, various hoses, tubes, hot melt adhesives, and the like.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1 Example 1 228 parts by weight of 2,2-bis (4-hydroxyphenyl) propane, potassium borohydride (10 ³ mol% based on the charged dihydroxy compound), diphenyl carbonate 214
After adding 1 part by weight and stirring at 180 ° C. for 1 hour under nitrogen, the temperature was gradually raised to 250 ° C., and the pressure in the system was reduced to 2 mmHg. Subsequently, the temperature was raised and reacted at 280 ° C. and 0.5 mmHg for 2 hours to obtain a polycarbonate. This polycarbonate is almost colorless and transparent, and has an intrinsic viscosity [η] of 0.434 measured at 20 ° C. in a methylene chloride solution and [η] = 1.11 × 10 ⁻⁴ ( _v ).
^0.82 [Encyclopedia of Polymer Science and Technology Vol. 10, p. 732, p. 1969
John Quirie and Sons, Inc .; Encyclope
dia of Polymer Science and Technology Vol 10 P732;
John Wiley & Sons Inc (1969) ] becomes the average molecular weight _v calculated using equation was 24,000. Tris (2,4-di-t) was added to 254 g of the polycarbonate thus obtained.
-Butylphenyl phosphite) 0.254 g (0.1% by weight based on the polymer) in a tumbler blender (Matsui Seisakusho)
The mixture is mixed by SK-B-50; SKB-50) and twin-screw extruder (Haake Butler Product HBI System 9)
0; extruded using HAAKE Buchler Product HBI System 90) and pelletized. As an evaluation of heat resistance, the thermal decomposition behavior was measured with a differential thermogravimetric analyzer (manufactured by Rigaku Denki Co., Ltd.) in a nitrogen stream at a heating rate of 10 ° C./min. The decomposition onset temperature (T _d ) is 426 ° C., the temperature at which the weight loss reaches 5% (T ₅ ) is 465 ° C., and the temperature at which the weight loss reaches 10% (T ₁₀ ) is 47.
8 ° C.

In addition, to evaluate hydrolysis resistance, 50
A sheet having a thickness of mm × 50 mm × 0.6 mm was prepared, suspended in a high-temperature and high-humidity tank at 90 ° C. and 100% RH, and the decrease in molecular weight due to hydrolysis was measured. After 30 days under the conditions of 90 ° C. and 100% RH (relative humidity), the retention ratio of the molecular weight to the initial molecular weight was 86.3%, and the appearance of the sheet was colorless and transparent, and no abnormality was observed.

Example 2 22.8 g of 2,2-bis (4-hydroxyphenyl) propane
(0.1 mol) and 0.164 g of 2-methylimidazole (2 × 10
^-2 mol) and 21.4 g (0.1 mol) of diphenyl carbonate, and the mixture is stirred at 180 ° C for 1 hour under nitrogen, and then gradually heated to 250 ° C.
℃, the pressure in the system was reduced to 2 mmHg, and Tris (2,4
-Di-t-butylphenyl phosphite) (0.025 g, 0.1% by weight based on the whole polymer). The estimated relative solution viscosity obtained from the stirring torque during this addition (polymer concentration: 0.5 / 100 ml, 20 ° C, methylene chloride solvent) is
The relative solution viscosity obtained by actually sampling a small amount of a part of the polymer was 1.18 and was 1.18. Continue to heat up 28
The mixture was reacted at 0 ° C. and 0.5 mmHg for 2 hours to obtain a polycarbonate. This polycarbonate is almost colorless and transparent, and the intrinsic viscosity [η] measured at 20 ° C. in methylene chloride solution is 0.489 and [η] = 1.11 × 10 ⁻⁴ ( _v ) ^0.82 [Encyclopedia of Polymer Science and Technology, Volume 10 732 pages 1969 John
Quilly and Sons, Inc .; Encyclopedia of P
olymer Science and Technology Vol 10 P732; John Wil
ey & Sons Inc (1969)], the average molecular weight _v was 27,800.

Example 3 Under exactly the same conditions as in Example 1, a dimethylamine borane complex (10 ^-2 mol% based on the charged dihydroxy compound) was added instead of sodium borohydride, and a reaction was carried out to obtain a polycarbonate. . Moreover, the heat resistance and the hydrolysis resistance were evaluated in the form of pellets in the same manner as in Example 1. The results are shown in Table 1.

Example 4 114 parts by weight of 2,2-bis (4-hydroxyphenyl) propane (50 mol%), 2,2-bis (4-hydroxy-3-t-
Butylphenyl) propane 170 parts by weight (50 mol%), diphenyl carbonate 214 parts by weight, 4-dimethylaminopyridine (10 ^-2 mol based on the charged dihydroxy compound)
%) And reacted under the same conditions as in Example 1 to obtain a polycarbonate copolymer. The pellets were formed in the same manner as in Example 1, and heat resistance and hydrolysis resistance were evaluated. The results are shown in Table 1.

Example 5 2,2.8 g of 2,2-bis (4-hydroxyphenyl) propane
(0.1 mol), bis (2,4,6-trichlorophenyl) carbonate 42.1 g (0.1 mol), dimethylaminopyridine 0.
0122g (10 ^-4 mol) under nitrogen, after 180 ° C. 1 hour agitation, in the same manner as in Example 2 when it reaches a relative solution viscosity was warmed 1.19 while the pressure was gradually reduced tris (2,4 0.025 g of di-t-butylphenylphosphite) was added to carry out the reaction.
Table 1 shows the hue, viscosity average molecular weight, thermal decomposition behavior and hydrolysis behavior of the obtained polymer.

(Comparative Example) Comparative Example 1 Tris (2,4) was added to the polycarbonate obtained in Example 1.
-Di-t-butylphenyl phosphite), and evaluated for heat resistance and hydrolysis resistance. The results are shown in Table 1.

Comparative Example 2 For the purpose of comparison in Example 2, as a known catalyst, lithium hydroxide which is an alkali metal hydroxide was used in an amount of 10 ^-3 mol% based on 2,2-bis (4-hydroxyphenyl) propane.
The reaction was carried out without using, in particular, tris (2,4-di-t-butylphenylphosphite).

The obtained polymer showed a high value of 26,500 as an average molecular weight, but was pale yellow and pyrolysis started at 375 ° C and 430 ° C
At a 10% weight loss. After 30 days in a hydrolysis test at 90 ° C. and 100% RH, the retention of the average molecular weight was only 65.3%. The test sheet became cloudy and many small white spots (including some voids) occurred on the entire surface. The conversion was remarkable. These results are shown in Table 1.

(Effects of the Invention) As shown in the results in Table 1, by adding a specific phosphite compound to the aromatic polycarbonate polymer, the heat resistance and hydrolysis resistance of the obtained resin composition are improved, and the It can be used in various fields as a plastic material.

Claims (2)

(57) [Claims] 1. A polycarbonate obtained by subjecting a divalent hydroxy compound and a bisaryl carbonate to melt polycondensation by a transesterification reaction in the presence of a transesterification reaction catalyst to a phos- phos represented by the following structural formula (I). A method for producing a polycarbonate for a general engineering plastic material, characterized by adding a phyt compound, wherein the hydrolysis resistance of the polycarbonate for a general engineering plastic material is 90 ° C. and 100% RH (relative humidity). After 30 days, the retention of the molecular weight to the initial molecular weight is 86% or more,
The temperature at which decomposition starts is 426 ° C or more and the temperature at which the weight loss reaches 5% is 465 ° C or more,
A process for producing polycarbonate for general engineering plastics materials with improved heat resistance and hydrolysis resistance at which the temperature at which the weight loss reaches 10% is 478 ° C or higher. 2. The method according to claim 1, wherein the addition of the phosphite compound represented by the structural formula (I) is carried out in the polycondensation step.
g / 100 ml, solvent: methylene chloride, sample temperature 20 ° C.), when the measured value is 1.17 or more, the polycarbonate resin for general engineering plastic material according to claim 1, characterized in that: Wherein the hydrolysis resistance of the polycarbonate for general engineering plastic materials is 90 ° C., 100% RH
After 30 days under the conditions of (Relative Humidity), the molecular weight retention rate with respect to the initial molecular weight is 86% or more, and the heat resistance is decomposed with a differential thermogravimetric analyzer under a condition of a nitrogen gas flow at a heating rate of 10 ° C / min. Starting temperature of 426 ° C or more, temperature at which weight loss reaches 5% is 465
A method for producing polycarbonate for general engineering plastics with improved heat resistance and hydrolysis resistance at temperatures of 478 ° C or higher at temperatures of 478 ° C or higher with a weight loss of 10% or higher.