JPH06287425A - Aromatic polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition of low chlorine content, excellent in corrosion resistance, thermal stability and color tone, useful as e.g. a transparent industrial material, by incorporating an aromatic polycarbonate resin with a specified amount of a specific phosphorous ester. CONSTITUTION:The objective composition can be obtained by incorporating (A) an aromatic polycarbonate resin produced by ester interchange reaction with (B) 0.0001-1wt.% of an aromatic phosphorous ester (derivative) of the formula [Ar is (substituted) phenyl or (substituted) naphthyl; n is 1 or 2]. It is preferable that the component A be prepared using an iminocarboxylic acid compound as catalyst for transesterification.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the thermal stability of an aromatic polycarbonate resin produced by a transesterification reaction (melting method).

[0002]

2. Description of the Related Art Aromatic polycarbonate resins have been widely used as engineering plastics for various purposes such as impact resistance, dimensional stability and transparency.
As its industrial production method, phosgene method, transesterification method, etc. are known, but when the obtained aromatic polycarbonate resin is melt-molded, a heat stabilizer is added to prevent a decrease in molecular weight and coloration. This is a known technique.

As such a heat stabilizer, various phosphites (Japanese Patent Publication No. 3713775 and Japanese Patent Laid-Open No. 58-1) are used.
26119), N-alkylphenothiazines (JP-A-4
9-47459), hindered phenol (JP-A-61-61)
-151236), epoxy compounds and the like are known. By using these stabilizers, it was possible to improve the thermal stability of the aromatic polycarbonate resin produced by the phosgene method to a level at which there is no practical problem.

[0004]

However, in the aromatic polycarbonate resin produced by the phosgene method, methylene chloride used as a solvent at the time of production has an extremely high affinity with the resin, so that it is completely removed from the resin. It is difficult to do this, and this residual methylene chloride decomposes during molding to generate hydrogen chloride gas and corrode the molding machine,
There were problems such as deterioration of the polymer. Therefore, in order to remove the residual methylene chloride in the polymer, it is necessary to dry for a long time, or it is necessary to add another solvent, and there is a problem that the cost increases industrially.

On the other hand, when the above-mentioned stabilizer is used in the aromatic polycarbonate resin prepared by the melting method, it has a sufficient thermal stability due to the influence of the catalyst such as the metal salt remaining in the resin. No aromatic polycarbonate composition was obtained. Thus, in the conventional aromatic polycarbonate resin composition, problems such as corrosion of the molding machine,
There was a problem with thermal stability.

[0006]

Means for Solving the Problems The present inventor has diligently studied to produce an aromatic polycarbonate resin composition having a low chlorine atom content and excellent thermal stability. The inventors have found that the above problems can be solved by adding a specific phosphorus compound to the aromatic polycarbonate resin to be used, and have reached the present invention.

That is, the gist of the present invention is to add 0.0001% by weight to 1% by weight of a phosphorus compound represented by the following general formula (I) or a derivative thereof to an aromatic polycarbonate resin produced by a transesterification method. And an aromatic polycarbonate resin composition.

[0008]

[Chemical 2]

(In the formula, Ar represents a phenyl group or a naphthyl group, the aromatic ring may be substituted, and n represents 1 or 2.) The present invention will be described in detail below. The aromatic polycarbonate resin by the transesterification reaction used in the present invention is an aromatic dihydroxy compound and a bisaryl carbonate as raw materials, which are polymerized in a heating and melting state, or a self-condensation of a carbonate precursor. Is. Furthermore, it has a relatively low molecular weight (for example, a viscosity average molecular weight of 2,000 to 20,000 in the transesterification reaction).
It also includes an aromatic polycarbonate resin obtained by producing the prepolymer of 0) and increasing its molecular weight by a reaction device such as an extruder or a step such as a solid phase polymerization method.

As the aromatic dihydroxy compound used as a raw material, those represented by the general formula (II) are used.

[0011]

[Chemical 3]

(In the formula, R ¹ and R ² each independently represent an optionally substituted alkyl group, nitro group, unsubstituted or substituted aryl group, and X is a single bond, an alkylene group, 2
A valent functional group is shown. Among these, particularly preferred are 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), bis (4-hydroxyphenyl) methane, 1,
1-bis (4-hydroxyphenyl) ethane, 1,1-
Bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) pentane, 3,3-bis (4-hydroxyphenyl) pentane, 2, 2-bis (3-methyl-4-hydroxyphenyl) propane,
1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4′-dihydroxydiphenyl ether, 4,
4'-dihydroxydiphenyl sulfide, 4,4'-
Examples thereof include dihydroxydiphenyl sulfoxide and 4,4′-dihydroxydiphenyl sulfone.

Further, as the carbonate precursor in the present invention, those represented by the general formula (III) are used.

[0014]

[Chemical 4]

(In the formula, R ³ and R ⁴ are independently Cl and B
R, F, and other halogens, nitro groups, alkyl groups having 1 to 20 carbon atoms, and aryl groups are shown, and m represents 0 to 20. X represents a single bond, an alkylene group or a divalent functional group. ) Of these, specifically, diphenyl carbonate,
Bis (p-chlorophenyl) carbonate, bis (p-
Examples thereof include nitrophenyl) carbonate, bisaryl carbonate of bisphenol A, and a polycarbonate oligomer having a phenyl carbonate group at the end.

In order to produce the aromatic polycarbonate used in the present invention by a transesterification reaction, in order to compensate for the distillation of bisaryl carbonate and the like during the polymerization, the bisaryl carbonate is added to the aromatic dihydroxy compound. The molar ratio is 1 to 2 times, preferably 1.05 to 1.5 times. Further, the aromatic polycarbonate of the present invention includes one having a branched structure. Furthermore, it is also possible to add terephthalic acid, dicarboxylic acid such as isophthalic acid or their derivatives to obtain an aromatic polyester carbonate.

As the polymerization catalyst, a known transesterification catalyst or the like is usually used. Specifically, alkali metal or alkaline earth metal phenolates, carbonates, acetates, hydroxides, etc., quaternary ammonium hydroxide such as tetramethylammonium hydroxide, imino such as ethylenediaminetetraacetic acid or nitrilotriacetic acid. Examples thereof include carboxylic acids and salts thereof, tertiary amines such as N, N, N ′, N′-tetramethylethylenediamine and salts thereof, and the like. Among these, iminocarboxylic acids and salts thereof are particularly preferable because they give a polymer having a good color tone. The polymerization may be carried out without using these catalysts.

Further, the aromatic acidic phosphoric acid ester (aryl acid phosphate) represented by the structural formula (I), which is used as a heat stabilizer in the present invention, is a monoester, a diester or a mixture thereof. Specific examples thereof include phenyl acid phosphate, tolyl acid phosphate, (tert-butylphenyl) acid phosphate, and naphthyl acid phosphate. These compounds can be used alone or in combination of two or more kinds.

These aromatic acidic phosphoric acid esters may be used as they are or as a derivative, for example, partly or wholly as a salt of an alkali metal, an alkaline earth metal, an amine or the like. Further, it can be used as a compound having a plurality of phosphorus atoms in one molecule such as aromatic acidic polyphosphate ester. The amount of the aromatic acid phosphate ester or its derivative added is 0.0001 to 1% by weight, preferably 0.001 to 1% by weight, particularly preferably 0.01 to 1% by weight based on the aromatic polycarbonate resin.
It is 0.1% by weight. If the amount of the aromatic acid phosphoric acid ester is less than 0.0001% by weight, the effect as a heat stabilizer becomes weak, which is not preferable. On the contrary, if the amount is more than 1% by weight, no particular effect is obtained by that, and further, the hydrolysis resistance of the resin may be adversely affected, which is not desirable.

Within the scope of the present invention, other known heat stabilizers can be used in combination, if necessary.
Further, other additives such as a filler can be added. As a method for adding the aromatic acid phosphoric acid ester to the polycarbonate resin, when a product polymer is added, the same method as that used for preparing a usual resin composition can be applied. For example, it can be carried out by a method of kneading the aromatic acid phosphoric acid ester with the resin by an extruder or the like.
Alternatively, a method of adding the aromatic polycarbonate resin at the time of charging the raw material of the aromatic polycarbonate resin by the transesterification reaction or during the production process may be adopted.

The aromatic polycarbonate resin composition produced by the method of the present invention is excellent in thermal stability, and has little decrease in molecular weight and mechanical properties during molding and little coloring. Therefore, the polycarbonate resin composition can be widely used as a general engineering plastic and is industrially extremely advantageous.

[0022]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. In addition, in each of the following examples, each measurement was performed by the following method. (1) Molecular weight (Mv) Intrinsic viscosity [η] (d) of a methylene chloride solution at 20 ° C
1 / g) was measured using an Ubbelohde viscosity tube, and the viscosity average molecular weight was calculated using the following formula.

[0023]

[Equation 1] [η] = 1.23 × 10 ⁻⁴ (Mv) ^0.83

(2) Thermal stability A polymer dried in a vacuum drier at 120 ° C. for 6 hours or more was compression molded at 280 ° C. for 6 minutes using a press molding machine to obtain a sheet. The thermal stability was evaluated by using the molecular weight retention rate before and after press molding. The sample having good thermal stability has a molecular weight retention of 90% or more, preferably 95% or more.

Example 1 Bisphenol A9 was placed in a reactor equipped with a stirring blade and replaced with nitrogen.
1.2 g and 98.5 g of diphenyl carbonate were charged, and 4.1 × 10 ⁻⁴ wt% of trilithium nitrilotriacetate as a catalyst was added to the produced polymer. This mixture was melted at 160 ° C., the temperature was gradually raised while raising the temperature, and the temperature was kept at 200 mmHg and 240 ° C. for a while,
Finally, a condensation reaction was performed at 0.2 mmHg and 300 ° C., and the produced phenol was distilled off to obtain an almost colorless polycarbonate resin having a viscosity average molecular weight of 19,600.

Next, 0.03% by weight of diphenyl phosphate was mixed with this polycarbonate resin, and then 2
It was pressed at 80 ° C. for 6 minutes to obtain a polycarbonate sheet. Since the viscosity average molecular weight of this sheet is 19,300 and the molecular weight retention rate is 98.5%, it can be seen that a polycarbonate resin composition having very excellent thermal stability was obtained.

Example 2 A polycarbonate resin composition was obtained in the same manner as in Example 1 except that the amount of diphenyl phosphate added was 0.01% by weight. The results are shown in Table 1. Example 3 The same procedure as in Example 1 was carried out except that ethylenediaminetetraacetic acid disodium was used as the polymerization catalyst. The results are shown in Table 1.

Comparative Example 1 Example 1 except that no heat stabilizer was used.
As a result of the same procedure as described above, as shown in Table 1, a resin composition colored in yellow was obtained. Comparative Example 2 As the heat stabilizer, 0.03 of tris (mono, dinonylphenyl) phosphite (manufactured by Asahi Denka Kogyo Co., Ltd., trade name: ADEKA STAB 329K) was used instead of diphenyl phosphate.
The same procedure as in Example 1 was carried out except that the weight% was used. The results are shown in Table 1.

[0029]

[Table 1]

[0030]

The aromatic polycarbonate resin composition according to the present invention has no problem due to residual methylene chloride and is excellent in heat resistance and color tone, so that it can be used in a wide range of applications.

Claims (2)

[Claims] 1. An aromatic polycarbonate resin produced by a transesterification reaction is mixed with 0.005 of an aromatic acidic phosphoric acid ester represented by the following general formula (I) or a derivative thereof.
An aromatic polycarbonate resin composition characterized by being blended in an amount of from 01% by weight to 1% by weight. [Chemical 1] (In the formula, Ar represents a phenyl group or a naphthyl group, the aromatic ring may be substituted with an alkyl group or another functional group, and n represents 1 or 2.) 2. An aromatic polycarbonate resin composition, wherein the aromatic polycarbonate resin according to claim 1 is an aromatic polycarbonate resin produced by using an iminocarboxylic acid or a salt thereof as a catalyst for a transesterification reaction. .