JP2001329156A - Aromatic polycarbonate resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aromatic polycarbonate resin composition having improved hue and heat resistance, suitable as a molding material for moldings such as an optical disc, a sheet or transparent moldings such as a glass substitute. SOLUTION: This aromatic polycarbonate resin composition is characterized by compounding 100 pts.wt. of an aromatic polycarbonate which is a polycarbonate produced by a reaction between an aromatic dihydroxy compound and a compound into which a carbonate bond can be introduced and having 12,000-40,000 viscosity-average molecular weight, which has <=1,000 ppm content of a specific cyclic oligomer in which the ratio of the cyclic oligomer content to the total oligomer content satisfies a specific relation and is incorporated with 0.001-1 pt.wt. of at least one kind of an antioxidant selected from a hindered phenol compound and a phosphorus compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polycarbonate resin composition having improved hue and heat resistance. This is particularly useful as a molding material for various molded articles such as optical disks and sheets, and transparent molded articles such as glass substitutes.

[0002]

2. Description of the Related Art Polycarbonate resins are widely used in many fields as resins having excellent impact resistance and transparency. However, since the polycarbonate resin has a high melt viscosity, it must be kneaded and molded at a high temperature of 250 to 380 ° C., and it is easy to color during kneading and molding.
Further, there is a problem that coloring is easy even under high-temperature use conditions. In order to solve these problems, polycarbonate produced by the interfacial method in which an aromatic dihydroxy compound and phosgene are reacted and polymerized is reduced by reducing the amount of methylene chloride used as a solvent and the amount of chlorine component derived from phosgene. Attempts have been made to improve the heat resistance, and in the transesterification method in which an aromatic dihydroxy compound and a carbonic acid diester compound are reacted under reduced pressure by heating, the content is reduced by reducing the amount of the raw material carbonic acid diester, etc., and the catalyst is deactivated. (JP-A-7-126374) has been attempted, but sufficient thermal stability has not been obtained. On the other hand, phosphorus-based antioxidants such as phosphites and the like, and antioxidants such as hindered phenols have been added to polycarbonates, and attempts to impart heat resistance have already been made. Could not be suppressed.

[0003]

SUMMARY OF THE INVENTION The present invention provides a polycarbonate resin composition having excellent color tone and heat resistance.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on the color tone, heat resistance and the like of a polycarbonate resin in order to solve the above problems. By combining the amount of the polycarbonate resin reduced to a specific amount and a specific ratio or less and at least one antioxidant selected from a specific phosphorus compound and a specific phenol compound, the color tone and heat resistance can be significantly improved. This finding has led to the completion of the present invention. That is, the present invention relates to a polycarbonate having a viscosity-average molecular weight of 12,000 to 40,000 produced by reacting an aromatic dihydroxy compound with a compound capable of introducing a carbonic acid bond, wherein the content of the cyclic oligomer represented by the formula (I) is as follows: Is 1000 ppm or less, and a ratio of the hindered phenol to 100 parts by weight of the aromatic polycarbonate satisfying the relational expression (1) with respect to the total amount of the oligomers represented by the formulas (I), (II) and (III) The present invention provides an aromatic polycarbonate resin composition comprising 0.001 to 1 part by weight of at least one antioxidant selected from a compound and a phosphorus compound.

[0005]

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(In the formula (I), B is a hydrocarbon group having 1 to 15 carbon atoms which may be halogen-substituted, O, S, C
It is a divalent group selected from O, SO and SO ₂ . X represents a halogen atom, an aliphatic group or a substituted aliphatic group having 1 to 14 carbon atoms, an aromatic group or a substituted aromatic group having 6 to 18 carbon atoms, an oxyalkyl group having 1 to 8 carbon atoms, and 6 carbon atoms.
And a monovalent group selected from oxyaryl groups of -18 to -18. m is an integer of 2 to 8, p is an integer of 0 to 4, and s is 0 or 1. X and p may be the same or different. )

[0007]

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(In the formula (II), A and A ′ are the same or different and each have an aliphatic group having 1 to 18 carbon atoms;
It represents a substituted aliphatic group, an aromatic group, or a substituted aromatic group. n
Is an integer of 1 to 7, and B, X, p and s have the same definition as in formula (I). )

[0009]

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(In the formula (III), A ″ represents an aliphatic group having 1 to 18 carbon atoms, a substituted aliphatic group, an aromatic group or a substituted aromatic group. N ′ represents an integer of 1 to 7, , X, p and s have the same definition as in formula (I).)

[0011]

(Equation 2)

(In the formula (1), [I], [II], [III]
Represents the content of the oligomer corresponding to each formula,
Mv represents the viscosity average molecular weight of the aromatic polycarbonate. )

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The aromatic polycarbonate according to the present invention can be produced by a known method such as an interfacial polycondensation method or a transesterification method using an aromatic dihydroxy compound and a compound capable of introducing a carbonic acid bond as raw materials. Among them, production by a transesterification method is preferred. Examples of the compound capable of introducing a carbonic acid bond include phosgene and carbonic acid diester. The carbonic acid diester is represented by the following formula (V).

[0014]

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(In the formula (V), A and A ′ each have 1 to 1 carbon atoms.
18 aliphatic groups, substituted aliphatic groups, aromatic groups, or substituted aromatic groups, which may be the same or different. )
The carbonic acid diester represented by the above formula (V) is, for example, dimethyl carbonate, diethyl carbonate, di-t-
Examples thereof include substituted diphenyl carbonates such as butyl carbonate, diphenyl carbonate, and ditolyl carbonate. Preferred are diphenyl carbonate and substituted diphenyl carbonate, and particularly preferred is diphenyl carbonate. These carbonate diesters may be used alone or in combination of two or more. A dicarboxylic acid or dicarboxylic acid ester may be used in an amount of preferably 50% or less, more preferably 30% by mole or less, together with the compound capable of introducing a carbonic acid bond as described above. Such dicarboxylic acids or dicarboxylic esters include terephthalic acid, isophthalic acid,
Diphenyl terephthalate, diphenyl isophthalate and the like are used. When such a carboxylic acid or a carboxylic acid ester is used in combination with a carbonic acid diester, a polyester carbonate is obtained. Another raw material, an aromatic dihydroxy compound, is represented by the formula (VI).

[0016]

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(In the formula (VI), B is a hydrocarbon group having 1 to 15 carbon atoms which may be substituted by halogen, or
It is a divalent group selected from O, S, CO, SO and SO ₂ . X is a halogen atom, an aliphatic group or a substituted aliphatic group having 1 to 14 carbon atoms, an aromatic group or a substituted aromatic group having 6 to 18 carbon atoms, an oxyalkyl group having 1 to 8 carbon atoms, and 6 to 18 carbon atoms. A monovalent group selected from oxyaryl groups. p is an integer of 0 to 4, and s is 0 or 1
It is. X and p may be the same or different. The aromatic dihydroxy compound represented by the above formula (VI) is, for example, 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A],
2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,
5-diethylphenyl) propane, 2,2-bis (4-
Hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxyphenyl) pentane, 2,4′- Dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-5-nitrophenyl) methane,
1,1-bis (4-hydroxyphenyl) ethane, 3,
3-bis (4-hydroxyphenyl) pentane, 1,1
-Bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4'-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4'-dihydroxydiphenylether, 4,4'- Dihydroxy-3,3'-dichlorodiphenyl ether, 4,4'-dihydroxy-
Examples thereof include 2,5-diethoxydiphenyl ether. Among these, 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A] is preferable. In addition, these aromatic dihydroxy compounds can be used alone or in combination of two or more, and can also be used as a copolymer if necessary.

The mixing ratio of the carbonic acid diester to the aromatic dihydroxy compound is determined by the desired molecular weight of the aromatic polycarbonate and the amount of terminal hydroxyl groups. The amount of terminal hydroxyl groups depends on the thermal stability of the product polycarbonate,
It has a significant effect on hydrolysis stability, color tone, etc., and is preferably 1,000 ppm in order to have practical physical properties.
Or less, more preferably 800 ppm or less, and particularly preferably 700 ppm or less. In the case of a polycarbonate produced by a transesterification method, if the amount of terminal hydroxyl groups is too small, the molecular weight does not increase and the color tone deteriorates.
0 ppm or more is more preferable, and 300 ppm or more is particularly preferable. Therefore, it is common to use the carbonate diester in an equimolar amount or more with respect to 1 mole of the aromatic dihydroxy compound, preferably from 1.01 to 1.30 mol, particularly preferably from 1.01 to 1.20 mol. Used in When an aromatic polycarbonate is produced by the transesterification method, a transesterification catalyst is usually used. The transesterification catalyst is not particularly limited, but an alkali metal compound and / or an alkaline earth metal compound is mainly used, and a basic boron compound, a basic phosphorus compound,
It is also possible to use a basic compound such as a basic ammonium compound or an amine compound in combination. These catalysts may be used alone or in combination of two or more. The catalyst is used in an amount of 1 × 10 ^-9 to 1 × 10 ^-3 mol per 1 mol of the aromatic dihydroxy compound. Particularly, in the case of an alkali metal compound or an alkaline earth compound, usually 1 × 10 ⁻⁹ to 1 × 10 ⁻⁴ mol, preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁵ mol per 1 mol of the aromatic dihydroxy compound. Used in the range, basic boron compounds, basic phosphorus compounds, basic ammonium compounds or basic compounds such as amine compounds,
1 × 10 ⁻⁹ to 1 mol of aromatic dihydroxy compound
It is used in an amount of 1 × 10 ⁻³ mol, preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻⁴ mol. If the amount of the catalyst is less than these amounts, the polymerization activity required for producing a polycarbonate having a predetermined molecular weight and a terminal hydroxy group amount cannot be obtained. It is not preferable because the color tone is deteriorated, the heat resistance is reduced, the hydrolysis resistance is reduced, and the amount of foreign substances is increased due to the generation of gel.

As the alkali metal compound, lithium,
Inorganic alkali metal compounds such as sodium, potassium, rubidium and cesium hydroxides, hydrogen carbonates, carbonates, acetates, hydrogen phosphates and phenyl phosphates; organic acids such as stearic acid and benzoic acid; methanol And organic alkali metal compounds such as salts with alcohols such as ethanol, phenolic acid, and phenols such as bisphenol A. Examples of the alkaline earth metal compound include inorganic alkaline earth metal compounds such as beryllium, calcium, magnesium, strontium, barium hydroxide, hydrogen carbonate, carbonate, and acetate, organic acids, alcohols,
Organic alkaline earth metal compounds such as salts with phenols and the like can be mentioned. Specific examples of the basic boron compound include tetramethyl boron, tetraethyl boron, tetrapropyl boron, tetrabutyl boron, trimethylethyl boron, trimethylbenzyl boron, trimethylphenyl boron, triethylmethyl boron, triethylbenzyl boron, triethylphenyl boron, tributyl Sodium, potassium, lithium, calcium, magnesium, barium or strontium salts of benzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, butyltriphenylboron, etc. Is mentioned. Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine,
Examples include triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.

Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide,
Trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltrimoxide Examples include phenylammonium hydroxide, methyltriphenylammonium hydroxide, and butyltriphenylammonium hydroxide. Examples of the amine compound include 4-aminopyridine, 2
-Aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2- Mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like can be mentioned. Of these catalysts, practically, alkali metal compounds, basic ammonium compounds, and basic phosphorus compounds are desirable, and alkali metal compounds are particularly desirable. The polycarbonate of the present invention uses the compound capable of introducing a carbonic acid bond and an aromatic dihydroxy compound, and is usually produced using the above-mentioned transesterification catalyst, and has a viscosity average molecular weight of 12,000 to 40,000. If the viscosity average molecular weight is less than 12,000, the mechanical strength decreases,
If it exceeds 00, the moldability is undesirably reduced.

In the aromatic polycarbonate of the present invention, the total content of the cyclic oligomer represented by the formula (1) needs to be 1000 ppm or less, preferably 700 ppm or less, more preferably 550 ppm or less. When the amount of the cyclic oligomer exceeds 1000 ppm, the oligomer is colored, and heat resistance, hydrolysis resistance and the like are reduced. The reason for this is not necessarily clear, but it is presumed that the cyclic oligomer is rich in reactivity and easily produces a coloring component at high temperature or promotes hydrolysis. Further, in the present invention, the ratio of the amount of the cyclic oligomer (I) to the total amount of the cyclic oligomer (I) and the oligomers represented by the formulas (II) and (III) does not satisfy the following relational expression (1). No.

[0022]

(Equation 3)

(In the formula (1), [I], [II], [III]
Represents the content of the oligomer corresponding to each formula,
Mv represents the viscosity average molecular weight of the aromatic polycarbonate. Both the cyclic oligomers represented by the formula (I) and the linear oligomers represented by the formulas (II) and (III) are considered to be components formed during the production of polycarbonate, and The structure of the repeating unit in parentheses in the formula is derived from the aromatic dihydroxy compound used in the production of polycarbonate. The compounds represented by the terminal groups A, A ′ and A ″ are derived from the terminal group of the compound capable of introducing a carbonic acid bond represented by the formula (V), and are obtained by interfacial polycondensation using phosgene. When the cyclic oligomer (I) is produced, it is derived from the terminal stopper used.
Above ppm, the properties are adversely affected. Further 1000
It has been found that even when the content of the cyclic oligomer (I) is less than ppm, if the proportion of the cyclic oligomer (I) exceeds the range of the above relational formula (1), physical properties are adversely affected. Reasons for worse physical properties are 100
Cyclic oligomer (I) as in the case of more than 0 ppm
This is probably because of high reactivity.

The mechanism of the formation of the cyclic oligomer (I) is not clear, but the heat history during the production of the polymer, the influence of the type and amount of the catalyst, the concentration of the monomer during the production of the polymer and the concentration of the aromatic hydroxy compound produced as a by-product, etc. The amount of generation changes due to the influence.
Generally, in order for a certain molecular chain to become a cyclic body, the terminal groups of the molecular chain need to react with each other. However, this is a reaction that usually does not easily occur. Generally, in the initial stage of polymerization, end groups between adjacent molecules react with each other, and the polymerization proceeds. However, when the polymerization proceeds and the ratio of terminal groups in the system changes, it is considered that the reaction between molecules is reduced and the reaction in the molecule is likely to occur. In particular, when a high temperature is maintained in a state where the number of terminal hydroxyl groups is small, a cyclic oligomer is easily formed. Therefore, it is preferable that the ratio of terminal hydroxyl groups is not extremely reduced during the production. For the purpose of merely reducing the content of the cyclic oligomer (I), the extraction treatment can be carried out with a solvent having a weak polycarbonate-dissolving power, such as hexane, heptane, methanol and acetone. However, in the extraction operation, the amount of the linear oligomer other than the cyclic oligomer is also reduced, and the ratio of the amount of the cyclic oligomer in the total amount of the oligomer does not change. There are many. Further, the heat resistance may not be improved due to the influence of the residual solvent due to the extraction operation, which is not preferable. The measurement of the content of the oligomer represented by the formula (I), the formula (II) or the formula (III) is performed by, for example, gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), mass spectrum, N
It can be measured using MR or the like. However, since it is generally necessary to separate a high molecular weight part and a low molecular weight part, MA
LDI-TOFMS (Matrix Assisted Lazer Desorpti
on Ionization Time of Flight Mass Spectrometory)
It is preferable to collectively measure from the high molecular weight part to the low molecular weight part using a measuring device such as

In the production of the polycarbonate of the present invention, the ester exchange reaction using the above-mentioned raw materials is carried out at 100 to 320 ° C.
At normal temperature or reduced pressure to carry out a melt polycondensation reaction while removing by-products such as aromatic hydroxy compounds. The melt polycondensation can be carried out batchwise or continuously, but in the present invention, it is preferably carried out continuously in view of product stability and the like. The reaction is usually carried out in two or more stages in which the temperature and pressure conditions are changed. The reaction temperature of each step is not particularly limited as long as the polymer is in a molten state within the above range, and the reaction time is also appropriately determined depending on the degree of progress of the reaction, but may be 0.1 to 10 hours. preferable. These conditions are determined in view of the molecular weight, hue and cyclic oligomer content of the polymer. Specifically, the first stage reaction is carried out at a temperature of 140 to 260 ° C., preferably 180 to 240 ° C. for 0.1 to 5 hours, preferably 0.5 to 3 hours under normal pressure or reduced pressure. Then, the reaction temperature was raised while increasing the degree of pressure reduction of the reaction system, and finally 240 to 3 mm 2 under a reduced pressure of 2 mmHg or less.
The polycondensation reaction is performed at a temperature of 20 ° C. An effective method as a production method for reducing the content of the cyclic oligomer is
In particular, in the final polymerization step in which the molecular weight is increased by 5% or more, the reaction is carried out at 250 ° C. or more, particularly 260 ° C. or more, under such conditions that the proportion of terminal hydroxyl groups at the inlet of the polymerization apparatus used in the reaction becomes 100 ppm or more. The polymerization is preferably performed, and more preferably at 200 ppm or more. Since the activation energy for the formation of the cyclic oligomer is high, and the higher the temperature, the more rapidly it is generated, the polymerization temperature in the final stage is preferably performed at 310 ° C. or lower. If the amount of the catalyst is too large,
It is considered that the carbonate bond is easily activated, and a reaction between the carbonate terminals which usually does not occur easily occurs, so that a cyclic oligomer is also easily formed. Controlling the conditions of each of these reaction tanks so as not to fluctuate as much as possible can suppress the amount of the cyclic oligomer.

The apparatus to be used may be any of a tank type, a tube type and a tower type, and includes a vertical polymerization tank equipped with various stirring blades, a horizontal single-axis or horizontal two-axis polymerization tank. Etc. can be used. The atmosphere in the apparatus is not particularly limited, but from the viewpoint of the quality of the polymer, the polymerization is preferably performed in an inert gas such as nitrogen gas at normal pressure or reduced pressure. One example of such a manufacturing method is schematically shown in FIG. After completion of the polymerization, the produced aromatic polycarbonate is usually recovered as pellets.In this case, in order to remove low molecular weight components such as monomers and by-products remaining in the resin, the aromatic polycarbonate may be passed through a vented extruder. It is possible. The extruder conditions at which the temperature is usually highest in the production process should be mild conditions in order to keep the generation of cyclic oligomers low. When the temperature is increased while the catalyst is active, a cyclic oligomer is formed. Therefore, it is preferable to deactivate the catalyst using a suitable deactivator. When a catalyst, particularly an alkali metal compound catalyst, is used, a compound that neutralizes the catalyst, for example, a sulfur-containing acidic compound or a derivative formed therefrom is used as a catalyst deactivator in the transesterification polycarbonate. The amount is preferably 0.5 to 10 equivalents, preferably 1 to the alkali metal of the catalyst.
5 to 5 equivalents, usually 1 to 100 ppm, preferably 1 to 20 ppm based on the produced polycarbonate.
Add within the range. Examples of sulfur-containing acidic compounds or derivatives formed therefrom are sulfonic acid, sulfinic acid, sulfuric acid or esters thereof, and specifically, dimethyl sulfate, diethyl sulfate, p-toluenesulfonic acid, its methyl, ethyl, Butyl, octyl and phenyl esters, benzenesulfonic acid, its methyl, ethyl, butyl, octyl, phenyl and dodecyl esters, benzenesulfinic acid, toluenesulfinic acid,
And naphthalenesulfonic acid. Of these compounds, esters of p-toluenesulfonic acid or esters of benzenesulfonic acid are preferred, and two or more of these compounds may be used.

The sulfur-containing acidic compound or a derivative formed therefrom can be added to the polycarbonate by any method. For example, a sulfur-containing acidic compound or a derivative formed therefrom can be added to a polycarbonate in a molten or solid state directly or diluted with a diluent, and dispersed. Specifically, it can be supplied and mixed in a polycondensation reactor, a transfer line from the reactor, or an extruder. Further, after mixing with polycarbonate pellets, flakes, powders and the like generated by a mixer or the like, the mixture can be supplied to an extruder and kneaded. In addition, when performing a reduced pressure treatment by venting in an extruder, or when adding water, further, an antioxidant selected from a hindered phenol compound and a phosphorus compound,
When adding other heat stabilizers, mold release agents, dyes, pigments, ultraviolet absorbers, antistatic agents, antifogging agents, organic / inorganic fillers, etc., the addition and treatment of these various additives May be performed simultaneously with the sulfur-containing acidic compound or a derivative formed therefrom, but it is preferable to add the sulfur-containing acidic compound or the derivative formed therefrom prior to addition or treatment thereof, and further knead the compound. .
In the present invention, at least one antioxidant selected from a hindered phenol compound and a phosphorus compound,
It is necessary to add 0.001 to 1 part by weight to 100 parts by weight of the above specific aromatic polycarbonate.
That is, the hindered phenol compound used in the present invention is preferably a compound represented by the following formula (IV).

[0028]

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(In the formula (IV), R ¹ and R ^{2 each} have 1 to 10 carbon atoms.
And Y may be the same or different, and Y is a hydrocarbon having 1 to 20 carbon atoms which may contain a functional group selected from an ester group, an ether group, and an amide group and / or a phosphorus atom. Z is a hydrocarbon group having 1 to 6 carbon atoms which may contain an oxygen atom and / or a nitrogen atom, a sulfur atom or a single bond, and g represents an integer of 1 to 4. ) Specifically, n-octadecyl-3-
(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] Pentaerythrityl-tetrakis [3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate], 3,9-bis [1,1-di-methyl-2- {β- (3-t-butyl-
4-hydroxy-5-methylphenyl) propionyloxydiethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, triethylene glycol-bis [3- (3-t-butyl-5- Methyl-4-hydroxyphenyl) propionate] 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5- Di-t-butyl-4-hydroxybenzyl) benzene, 2,2-thio-diethylenebis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, N,
N'-hexamethylenebis (3,5-di-t-butyl-
4-hydroxy-hydrocinnamide) and the like. Among these, n-octadecyl-3- (3 ′,
5'-di-t-butyl-4'-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3-
(3 ′, 5′-t-butyl-4′-hydroxyphenyl) propionate], 3,9-bis [1,1-di-methyl-2- {β- (3-t-butyl-4-hydroxy-
5-methylphenyl) propionyloxydiethyl]-
2,4,8,10-Tetraoxaspiro [5,5] undecane is preferred.

The phosphorus compound used in the present invention is preferably a trivalent phosphorus compound. In particular, at least one of the phosphites has at least one phenol and / or an alkyl group having 1 to 25 carbon atoms. Phosphorous ester esterified with phenol having one or tetrakis (2,4-di-t-butylphenyl)
It is preferably at least one selected from -4,4'-biphenylene-di-phosphonite. Specific examples of the phosphite include 4,4'-butylidene-bis (3-methyl-6-t-butylphenyl-di-tridecyl) phosphite and 1,1,3-tris (2-methyl-
4-ditridecyl phosphite-5-t-butylphenyl) butane, trisnonylphenyl phosphite, dinonylphenylpentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2 , 4-Di-t-butylphenyl) pentaerythritol diphosphite, di (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2′-ethylidene-bis (4, 6-ditert-butylphenyl) fluoride phosphite,
Phosphorous acid consisting of 2,2'-methylene-bis (4,6-di-t-butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite, monononylphenol and dinonylphenol Esters, and further, phosphites having a hindered phenol represented by the formula (VII) can be exemplified. In the present invention, as the phosphorus compound,
Tetrakis (2,4-di-t-butylphenyl) -4,
4'-biphenylene-di-phosphonite or tris (2,4-di-t-butylphenyl) phosphite,
2,2'-methylene-bis (4,6-di-t-butylphenyl) octyl phosphite is preferred.

[0031]

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The compounding amount of at least one antioxidant selected from the phenol compound and the phosphorus compound is 0.001 to 100 parts by weight of the aromatic polycarbonate.
To 1 part by weight, preferably 0.01 to 0.4 part by weight. If the amount is less than 0.001 part by weight, the effect is not sufficient. If the amount is more than 1 part by weight, there is a problem that hydrolysis resistance is deteriorated. In addition, when the phenol compound and the phosphorus compound are used in combination, the mixing ratio can be arbitrarily determined, and which one to use or to use together is appropriately determined depending on the use of the resin composition and the like. You. Phenol compounds generally have a high effect on heat stability during use after forming a resin composition such as heat aging resistance, and phosphorus compounds generally have a retention stability at high temperature when molding a resin composition. , And is highly effective in heat stability during use of molded articles. Further, by using a phenol compound and a phosphorus compound in combination, the effect of improving coloring properties is enhanced. There are no particular restrictions on the timing of addition of the antioxidant and the method of addition.For example, as the timing of addition, when a polycarbonate is produced by a transesterification method, during the polymerization reaction or at the end of the polymerization reaction, and further in the polymerization method, Regardless, the polycarbonate can be added in a molten state such as during kneading of the polycarbonate or the like, but can also be kneaded with an extruder or the like after blending with a solid-state polycarbonate such as pellets or powder. In addition, particularly in the transesterification polycarbonate, in order to suppress the decomposition of the antioxidant, the above-mentioned sulfur-containing acidic compound, or a catalyst deactivator such as a derivative formed therefrom, is added after deactivating the polymerization catalyst. Is preferred.

As an addition method, the antioxidant can be directly mixed or kneaded with the polycarbonate.
It can also be dissolved in a suitable solvent or added as a high-concentration masterbatch made of a small amount of polycarbonate or other resin. When a phosphorus compound and a phenol compound are used in combination, it is possible to separately add these to the polycarbonate,
It is preferable to add them simultaneously. The aromatic polycarbonate resin composition of the present invention may further contain ordinary sulfur-based heat-resistant stabilizers, ultraviolet absorbers, release agents, coloring agents, antistatic agents, slip agents, anti-blocking agents, lubricants, anti-fog. Additives such as oils, natural oils, synthetic oils, waxes, organic fillers and inorganic fillers may be added. Such additives can be added to the resin in a molten state,
Further, the resin once pelletized can be remelted and added.

[0034]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the following examples, the production of the aromatic polycarbonate was performed using the steps as shown in FIG. Also,
The analysis of the aromatic polycarbonate obtained by the present invention was performed by the following measurement method. (1) Viscosity average molecular weight The intrinsic viscosity [η] at 20 ° C. in methylene chloride was measured using an Ubbelohde viscometer, and determined by the following equation.

[0035]

[Η] = 1.23 × 10 ⁻⁴ × (Mv) ^0.83

(2) Oligomer content MALDI-TOFMS (VIS manufactured by Finniganmat Co., Ltd.)
ION2000; laser (N ₂ laser = 337N
m) and the measured mass range (m / z = 0 to 35000)) were used for the measurement. 0.10 g of polycarbonate in 10 ml of dichloromethane and tris (3,5-di-t
-Butyl-4-hydroxybenzyl) isocyanurate (0.01 g) was dissolved in THF (1 ml)
Inside, 2,4,6-trihydroxyacetophenone 80m
g of a matrix solution was prepared, and the polymer solution and the matrix solution were mixed at a volume ratio of 1: 1 and used as a sample solution. (3) Initial color tone After drying the resin composition at 120 ° C. for 4 hours, 3 mm using an M150AII-SJ injection molding machine manufactured by Meiki Seisakusho Co., Ltd.
A thick molded product is molded under the conditions of 320 ° C. and a molding cycle of 1 minute, and a spectroscopic colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd., SE
2000). The larger the YI value, the more colored. (4) Retention stability (320 ° C. heat resistance test) After drying the resin composition at 120 ° C. for 4 hours, 3 mm using an M150AII-SJ injection molding machine manufactured by Meiki Seisakusho Co., Ltd.
The thick molded product was molded under the conditions of 320 ° C. and a molding cycle of 10 minutes, and the YI was measured by the transmission method using SE2000 manufactured by Nippon Denshoku Industries Co., Ltd. for the molded product of the fifth shot under these conditions. (5) Heat Aging Test The molded pieces for which the initial color tone was measured were subjected to a heat aging test in a hot air dryer at 110 ° C. for 2000 hours, and the YI after the treatment was measured. (6) Amount of Terminal Hydroxyl Group Colorimetric determination was performed by the titanium tetrachloride / acetic acid method (method described in Macromol. Chem. 88 215 (1965)).

Example 1 Bisphenol A (B
PA) and diphenyl carbonate (DPC) are melt-mixed at a fixed molar ratio (DPC / BPA = 1.045),
The polymer is continuously supplied through a raw material introduction tube heated to 135 ° C. into a vertical first stirred polymerization tank controlled at 205 ° C. under a normal pressure and a nitrogen atmosphere, and the polymer at the bottom of the tank is controlled so that the average residence time is 70 minutes. By controlling the valve opening provided on the discharge line,
The liquid level was kept constant. At the same time as the supply of the raw material mixture was started, cesium hydroxide in the form of an aqueous solution was added as a catalyst in an amount of 1 × 10 6
^It was continuously fed at a flow rate of ^-6 mol. The polymerization liquid discharged from the tank bottom was successively and continuously supplied to the second, third, and fourth vertical polymerization tanks and the horizontal fifth polymerization tank. During the reaction, the liquid level was controlled so that the average residence time of each tank was a predetermined time as shown in Table 1 below, and at the same time, phenol produced as a by-product was distilled off. Table 1 below shows the polymerization conditions in each reaction tank, the monomer content, and the like, from the vertical second polymerization tank to the horizontal fifth polymerization tank. While a polycarbonate obtained continuously at a production rate of 50 kg / Hr is kept in a molten state, a thermometer for measuring an internal temperature is installed in a kneading section, and a twin screw extruder (Kobe Steel ( Co., Ltd., screw diameter 0.046 m, L / D = 36), 5 ppm of butyl p-toluenesulfonate was added, water was added, the water and the monomer component were volatilized, and then pelletized. did. The condition of the extruder is as follows: discharge rate = 50 kg / hr, rotation speed = 1
50 rpm, maximum resin temperature = 278 ° C. The viscosity average molecular weight of the obtained polycarbonate was 22,000, the amount of cyclic oligomer was 400 ppm, and the ratio of the amount of cyclic oligomer calculated by the formula (1) was 13.7%.
This polymer was mixed with the antioxidant shown in Table 1 and mixed with a single screw extruder (trade name: VS-4, manufactured by Tanabe Plastics Co., Ltd.).
After kneading at a barrel temperature of 280 ° C according to 0), injection molding was performed at 320 ° C, and initial color tone, heat aging resistance, and retention stability were evaluated. The results are shown in Table 1.

Example 2 In Example 1, the catalyst was changed to sodium hydroxide,
A polycarbonate was obtained in the same manner except that the polymerization conditions and the like were changed as shown in Table 1. This polymer was mixed with the antioxidant shown in Table 1 and kneaded with a single screw extruder (trade name: VS-40, manufactured by Tanabe Plastic Co., Ltd.) at a barrel temperature of 280 ° C., followed by injection molding at 320 ° C. The initial hue, heat aging resistance, and retention stability were evaluated in the same manner as in Example 1. Table 1 summarizes the obtained evaluation results. Example 3 In Example 1, the catalyst was changed to cesium carbonate, and the polymerization conditions were changed to those shown in Table 1 without using a horizontal polymerization tank.
The same procedure was followed to obtain a polycarbonate. This polymer was mixed with the additives shown in Table 1 and kneaded with a single screw extruder (trade name: VS-40, manufactured by Tanabe Plastics Co., Ltd.) at a barrel temperature of 280 ° C., followed by injection molding at 320 ° C. to carry out initial hue and heat resistance. Aging properties and retention stability were evaluated. Table 1 also summarizes the evaluation results of the obtained polymers. Comparative Example 1 A polycarbonate was obtained in substantially the same manner as in Example 2 except that the conditions of the extruder were changed as shown in the table below. This polymer was mixed with the additives shown in Table 1 and mixed with a single screw extruder (trade name VS- manufactured by Tanabe Plastics Co., Ltd.).
After kneading at a barrel temperature of 280 ° C. according to 40), injection molding was performed at 320 ° C. to evaluate the initial hue, heat aging resistance and retention stability. Table 1 also summarizes the evaluation results of the obtained polymers.

Comparative Example 2 Kneading and molding were performed in substantially the same manner as in Example 1 except that no additive was added to the polymer, and the initial hue, heat aging resistance and retention stability were evaluated. Table 1 also summarizes the evaluation results of the obtained polymers. Comparative Example 3 In Comparative Example 1, kneading and molding were performed in substantially the same manner except that no additive was added to the polymer, and the initial hue, heat aging resistance, and retention stability were evaluated. Table 1 also summarizes the evaluation results of the obtained polymers.

[0040]

[Table 1]

[0041]

The aromatic polycarbonate resin composition of the present invention is excellent in hue and heat resistance.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing an example of a production method for obtaining a polycarbonate of the present invention.

[Explanation of symbols]

1. Raw material mixing tank 2. 2. Vertical polymerization tank Stirrer blade 4. 4. By-product discharge pipe Horizontal polymerization tank 6. Stirring blade 7. Catalyst introduction pipe

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Michio Nakata 5-6-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa F-term in the Technology Center of Mitsubishi Engineering-Plastics Co., Ltd. (Reference) 4J002 CG001 CG011 CG021 CG031 EJ046 EJ066 EP026 EU196 EV096 EW066 EW126 FD076 GP00 GS02

Claims (5)

[Claims] 1. A polycarbonate having a viscosity average molecular weight of 12,000 to 40,000, produced by reacting an aromatic dihydroxy compound with a compound capable of introducing a carbonic acid bond, comprising a cyclic oligomer represented by the formula (I). Quantity 1
100 ppm or less, and the ratio of the aromatic polycarbonate 100 satisfying the relational expression (1) to the total amount of the oligomers represented by the formulas (I), (II) and (III).
0.005 parts by weight of at least one antioxidant selected from a hindered phenol compound and a phosphorus compound is added.
An aromatic polycarbonate resin composition, which is added in an amount of 1 to 1 part by weight. Embedded image (In the formula (I), B is a hydrocarbon group having 1 to 15 carbon atoms which may be substituted with halogen, a divalent group selected from O, S, CO, SO and SO _2. X is a halogen. An atom, an aliphatic group having 1 to 14 carbon atoms or a substituted aliphatic group,
It represents a monovalent group selected from an aromatic group or a substituted aromatic group having 6 to 18 carbon atoms, an oxyalkyl group having 1 to 8 carbon atoms, and an oxyaryl group having 6 to 18 carbon atoms. m is 2
An integer of 8, p is an integer of 0 to 4, and s is 0 or 1. X and p may be the same or different. ) (In the formula (II), A and A ′ are the same or different and each represent an aliphatic group having 1 to 18 carbon atoms, a substituted aliphatic group, an aromatic group, or a substituted aromatic group. Integers of 1 to 7, B, X, p and s have the same definition as in formula (I). (In the formula (III), A ″ represents an aliphatic group having 1 to 18 carbon atoms, a substituted aliphatic group, an aromatic group, or a substituted aromatic group. N ′
Is an integer of 1 to 7, and B, X, p and s have the same definition as in formula (I). ) (Equation 1) (In the formula (1), [I], [II], and [III] each represent the content of the oligomer corresponding to each formula, and Mv represents the viscosity average molecular weight of the aromatic polycarbonate.) 2. A phosphite wherein the phosphorus compound is obtained by esterifying at least one ester in a phosphite with phenol and / or a phenol having at least one alkyl group having 1 to 25 carbon atoms. ,
And tetrakis (2,4-di-t-butylphenyl)-
The aromatic polycarbonate resin composition according to claim 1, which is at least one phosphorus compound selected from 4,4'-biphenylene-di-phosphonite. 3. The hindered phenol compound of the formula (I)
The aromatic polycarbonate resin composition according to claim 1, which is represented by V). Embedded image (In the formula (IV), R ¹ and R ² are a hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different, and Y is a functional group selected from an ester group, an ether group, and an amide group; Z is a hydrocarbon group having 1 to 20 carbon atoms which may contain a phosphorus atom, and Z is a hydrocarbon group having 1 to 6 carbon atoms which may contain an oxygen atom and / or a nitrogen atom, a sulfur atom or A single bond, and g represents an integer of 1 to 4.) 4. The aromatic polycarbonate resin composition according to claim 1, wherein the aromatic polycarbonate is produced by a transesterification reaction between an aromatic dihydroxy compound and a carbonic acid diester. 5. The aromatic polycarbonate resin composition according to claim 1, wherein the aromatic polycarbonate has a terminal hydroxyl group content of 100 to 1000 ppm.