KR20090131261A - Polycarbonate copolymer and process for producing the same, resin composition and molded article - Google Patents

Abstract

PURPOSE: A polycarbonate copolymer is provided to reduce yellowing generated in molding at a high temperature by restricting the tin content within a copolymer to be less than 0.5 ppm, and to reduce discoloration in a durability test. CONSTITUTION: A polycarbonate copolymer has a repeating unit represented by the following chemical formula I and II. The tin content (as an element) is 0.5 ppm or less. In the chemical formula I and II, R^1 and R^2 are independently C1-6 alkyl group; X is a single bond and represents any one selected from C1-8 alkylene group, C2-8 alkylidene group, C5-15 cycloalkylene group, C5-15 cycloalkylidene group, -S-, -SO-, -SO2-, -O-, -CO- or a bond represented by the following chemical formula III-1 or III-2; R^3 and R^4 are independently C1-3 alkyl group; Y is C2-15 linear or branched alkylene group; a-d are an integer of 0-4; and n is an integer of 2-200.

Description

POLYCARBONATE COPOLYMER AND PROCESS FOR PRODUCING THE SAME, RESIN COMPOSITION AND MOLDED ARTICLE}

BACKGROUND OF THE INVENTION Field of the Invention The present invention is a polycarbonate copolymer having excellent color tone and durability at high temperature molding, a method for producing the same, a resin composition comprising the copolymer, and a molded article. It is useful in the field of absence.

Polycarbonate (hereinafter sometimes abbreviated as "PC") copolymers are mainly produced from bisphenol A as a raw material, and PC copolymers are constantly desired to be improved in various properties. PCs produced from bisphenol A and the like are used for a wide range of applications because of their excellent transparency, heat resistance and mechanical properties (particularly impact resistance). However, when the molded article of the PC is used for an optical component such as a lens, a light guide plate, or an optical disk, there is a drawback that a satisfactory molded article cannot be obtained because of low fluidity, and it is desired that the fluidity is further improved. Carbonates have been proposed.

For example, as a method of improving fluidity, a method of changing the structure of a PC copolymer by copolymerization, modification of molecular chain ends, or the like has been reported. For example, the PC copolymer which modified the molecular chain terminal by the long-chain alkyl group is proposed (for example, refer patent document 1).

However, the terminal-modified PC copolymer obtained by this method has a limit in the amount of long chain alkyl group introduced because only the molecular chain terminal portion acts on the fluidity improvement, and the magnitude of the fluidity improvement was not sufficient.

Moreover, the polycarbonate copolymer which copolymerized polytetramethylene glycol bis (4-hydroxybenzoate) is known by patent document 2. As shown in FIG. It is known that this copolymer not only has remarkably improved the fluidity at the time of molding but also has excellent thermal stability, so that it can cope with a wide range of molding conditions as a molding raw material, and as a result, a good optical molded article can be obtained.

However, a polycarbonate copolymer is continuously produced by copolymerizing polytetramethylene glycol bis (4-hydroxybenzoate) described in Patent Document 2, and the copolymer is molded at a high temperature of higher than 320 ° C. When used under conditions, yellowing occurs.

In general, the causes of yellowing of various polycarbonate copolymers are often caused by impurities remaining in the comonomer in the polycarbonate copolymer. However, since the comonomer used and its use situation differ for each copolymer, the impurity which causes and a usage method are also different for every comonomer, and it makes it difficult to solve the yellowing problem of various polycarbonate copolymers (patent document 3). To 6).

Such yellowing is also caused by a high molding temperature, but also has a large influence by the catalyst contained in the copolymer. In preparing a phenol-modified diol, which is a raw material of the polycarbonate copolymer, in particular, when a tin catalyst is used, a conventional raw material refining process (for example, see Patent Document 7) or a polycarbonate purification step (for example, see Patent Document 8). In the polycarbonate copolymer which is not completely removed but is produced by continuously polymerizing the phenol-modified diol by interfacial polymerization or melt polymerization, tin compounds derived from tin catalysts of about several ppm to several tens ppm remain.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-96180

Patent Document 2: Japanese Patent Application Laid-Open No. 2005-247947

Patent Document 3: Japanese Patent Application Laid-Open No. 2004-315747

Patent Document 4: Japanese Patent Application Laid-Open No. 2005-336332

Patent Document 5: Japanese Patent Application Laid-Open No. 2006-28391

Patent Document 6: Japanese Patent Application Laid-Open No. 2007-70392

Patent Document 7: Japanese Patent Application Laid-Open No. 2005-232287

Patent Document 8: Japanese Patent Application Laid-Open No. 1989-96212

The present invention has been made in view of the above circumstances, and it is possible to produce a polycarbonate copolymer using a phenol-modified diol, and to prepare a polycarbonate copolymer using a high-purity phenol-modified diol capable of improving thermal stability under high temperature. It is an object to provide a carbonate copolymer, a resin composition, a molded article, and a method for producing a copolymer.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, it discovered that the said problem can be solved by controlling content of the impurity derived from the synthetic raw material of the polycarbonate copolymer represented by following formula (I) mentioned later. This invention is completed by this knowledge.

That is, the present invention,

(1) A polycarbonate copolymer having a repeating unit represented by the following formulas (I) and (II), wherein the tin content (as an element) is 0.5 ppm or less:

[Formula I]

[Formula II]

[R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms. X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-,- SO _2- , -O-, -CO- or any of the bonds represented by the following general formula III-1 or the following general formula III-2.

[Formula III-1]

[Formula III-2]

R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms. Y represents a C2-C15 linear or branched alkylene group. a to d are each independently an integer of 0 to 4, n is an integer of 2 to 200;

(2) A method for producing a polycarbonate copolymer according to the above (1), wherein a phenol-modified diol synthesized in the presence of a tin catalyst and treated with an aqueous phosphoric acid solution or a solid adsorbent is used as a comonomer,

(3) The manufacturing method of the polycarbonate copolymer as described in said (2) whose tin content (as an element) in the said phenol modified diol is 10 ppm or less,

(4) a polycarbonate resin composition comprising 100 parts by mass of the polycarbonate copolymer of (1) and 0.01 to 0.5 parts by mass of an antioxidant,

(5) The polycarbonate resin composition according to the above (4), wherein the yellow index (YI) of the molded article is 1.5 or less, and

(6) The molded article formed by shape | molding the resin composition of said (4) or (5) is provided.

According to the present invention, by forming the tin content in the polycarbonate copolymer to be 0.5 ppm or less, a yellow molded product generated in molding under a high temperature can be reduced, and further, a molded article can be obtained as a result by reducing discoloration in the durability test.

The polycarbonate (PC) copolymer of the present invention is a polycarbonate obtained by copolymerizing a phenol-modified diol and can be produced by a conventional production method called an interfacial polymerization method. That is, it can manufacture by the method of making carbonate precursors, such as dihydric phenol, a phenol modified diol, and phosgene, react.

Specifically, in an inert solvent such as methylene chloride, a catalyst or a branching agent is further added, if necessary, in the presence of a known acid acceptor or a molecular weight modifier, such as divalent phenol, phenol-modified diol, phosgene, and the like. The carbonate precursor is reacted. The PC copolymer has repeating units represented by the following formulas (I) and (II).

[Formula I]

[Formula II]

In the formulas (I) and (II), R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms. X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-,- SO _2- , -O-, -CO- or any of the bonds represented by the following general formula III-1 or the following general formula III-2.

[Formula III-1]

[Formula III-2]

R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms, and Y represents a linear or branched alkylene group having 2 to 15 carbon atoms. a to d are each independently an integer of 0 to 4, n is an integer of 2 to 200, preferably 6 to 70.

The alkyl group of R ¹ to R ⁴ may be either linear or branched. As a specific example of the alkyl group of R <^1> and R <^2> , a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert- butyl group, n-pentyl group, isopentyl group, n-hex Practical group, isohexyl group, etc. are mentioned.

As a specific example of the alkyl group of R <^3> and R <^4> , a methyl group, an ethyl group, n-propyl group, and isopropyl group are mentioned.

R ¹ and R ² may each independently be a cyclic hydrocarbon group such as a cyclopentyl group or a cyclohexyl group.

As a C1-C8 alkylene group of X, a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, etc. are mentioned, for example.

As a C2-C8 alkylidene group of X, an ethylidene group, an isopropylidene group, etc. are mentioned, for example.

As a C5-C15 cycloalkylene group of X, a cyclopentylene group, a cyclohexylene group, etc. are mentioned, for example. As a C5-C15 cycloalkylidene group of X, a cyclopentylidene group, a cyclohexylidene group, etc. are mentioned, for example.

As bivalent phenol, the compound represented by following formula (Ia) is mentioned.

Formula Ia

R ¹ and R ² in Formula Ia, a and b, and X are the same as above.

Although there are various divalent phenols represented by the above formula (Ia), 2,2-bis (4-hydroxyphenyl) propane [common name: bisphenol A] is particularly suitable. Examples of bisphenols other than bisphenol A include bis (hydroxyaryl) alkane, bis (hydroxyaryl) cycloalkane, dihydroxyarylether, dihydroxydiaryl sulfide and dihydroxydiaryl sulfoxide. Dihydroxy diaryl sulfones, dihydroxy diphenyls, dihydroxy diaryl fluorenes, dihydroxy diaryl adamantanes, bis (4-hydroxyphenyl) diphenyl methane, 4 , 4 '-[1,3-phenylenebis (1-methylethylidene) bisphenol, 10,10-bis (4-hydroxyphenyl) -9-anthrone, 1,5-bis (4-hydroxy Phenylthio) -2,3-dioxapentaene, the (alpha), (omega) -bishydroxyphenyl polydimethylsiloxane compound, etc. are mentioned. These dihydric phenols may be used independently, respectively and may be used in combination of 2 or more type.

As a molecular weight modifier, various things can be used as long as it is normally used for superposition | polymerization of PC resin. Specifically as monohydric phenol, for example, phenol, on-butylphenol, mn-butylphenol, pn-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, ot-butylphenol , mt-butylphenol, pt-butylphenol, on-pentylphenol, mn-pentylphenol, pn-pentylphenol, on-hexylphenol, mn-hexylphenol, pn-hexylphenol, pt-octylphenol, o-cyclohexyl Phenol, m-cyclohexylphenol, p-cyclohexylphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, on-nonylphenol, m-nonylphenol, pn-nonylphenol, o-cumylphenol, m -Cumylphenol, p-cumylphenol, o-naphthylphenol, m-naphthylphenol, p-naphthylphenol; 2,5-di-t-butylphenol; 2,4-di-t-butylphenol; 3,5-di-t-butylphenol; 2,5-dicumylphenol; 3,5-dicumylphenol; p-cresol, bromophenol, tribromophenol, monoalkylphenol having a straight or branched alkyl group having an average carbon number of 12 to 35 in the ortho, meta or para position; 9- (4-hydroxyphenyl) -9- (4-methoxyphenyl) fluorene; 9- (4-hydroxy-3-methylphenyl) -9- (4-methoxy-3-methylphenyl) fluorene; 4- (1-adamantyl) phenol etc. are mentioned. Among these monohydric phenols, p-t-butylphenol, p-cumylphenol, p-phenylphenol and the like are preferably used.

As the catalyst in the interfacial polymerization method, a phase transfer catalyst such as a tertiary amine or a salt thereof, a quaternary ammonium salt, a quaternary phosphonium salt, and the like can be preferably used. Examples of the tertiary amines include triethylamine, tributylamine, N, N-dimethylcyclohexylamine, pyridine, dimethylaniline, and the like, and examples of the tertiary amine salts include hydrochloride salts of these tertiary amines, Bromate, and the like. Examples of quaternary ammonium salts include trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide, and the like. Tetrabutyl phosphonium chloride, tetrabutyl phosphonium bromide, etc. are mentioned. These catalysts may be used independently, respectively and may be used in combination of 2 or more type. Among the catalysts, tertiary amines are preferred, and triethylamine is particularly suitable.

There are various inert organic solvents. For example, dichloromethane (methylene chloride); Trichloromethane; Carbon tetrachloride; 1,1-dichloroethane; 1,2-dichloroethane; 1,1,1-trichloroethane; 1,1,2-trichloroethane; 1,1,1,2-tetrachloroethane; 1,1,2,2-tetrachloroethane; Pentachloroethane; Chlorinated hydrocarbons such as chlorobenzene, toluene, acetophenone and the like. These organic solvents may be used alone, or two or more thereof may be used in combination. Among them, methylene chloride is particularly suitable.

As the branching agent, for example, 1,1,1-tris (4-hydroxyphenyl) ethane; 4,4 '-[1- [4- [1- (4-hydroxyphenyl) -1-methylethylphenyl] ethylidene] bisphenol; α, α ', α "-tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene; 1- [α-methyl-α- (4'-hydroxyphenyl) ethyl] -4- Compounds having three or more functional groups such as [α ', α'-bis (4' '-hydroxyphenyl) ethyl] benzene, fluoroglycine, trimellitic acid, and izatinbis (o-cresol) can also be used. .

The phenol-modified diol used in the present invention is represented by the following general formula (IIa).

[Formula IIa]

In the formula (IIa), R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms, and Y represents a linear or branched alkylene group having 2 to 15 carbon atoms. c and d are each independently an integer of 0 to 4, n is an integer of 2 to 450.

As an alkyl group represented by R <^3> and R <^4> , a methyl group, an ethyl group, n-propyl group, and isopropyl group are mentioned. When R ³ is plural, a plurality of R ³ may be the same as or different from each other, and when R ⁴ is plural, a plurality of R ⁴ may be identical to or different from each other. Examples of the linear or branched alkylene group having 2 to 15 carbon atoms represented by Y include alkylene groups such as ethylene group, propylene group, butylene group, isobutylene group, pentylene group and isopentylene group, ethylidene group, propylidene group, Alkylidene residues, such as an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group, and an isopentylidene group, are mentioned. It is preferable that n is 2-200, More preferably, it is 6-70.

The phenol-modified diol represented by the formula (IIa) is a compound derived from the hydroxybenzoic acid represented by the following formula (IV) or formula (V) or an alkyl ester thereof and polyetherdiol described later by an esterification reaction or an ester exchange reaction.

[Formula IV]

[Formula V]

In said Formula (V) and Formula (IV), R <^3> represents a C1-C3 alkyl group. c is an integer of 0-4. The alkyl group having 1 to 3 carbon atoms is described above.

In formula (V), R ⁴ represents an alkyl group having 1 to 3 carbon atoms, and R ⁵ represents an alkyl group having 1 to 10 carbon atoms. d is an integer of 0-4. As a C1-C10 alkyl group, in addition to the C1-C3 alkyl group mentioned above, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, 2-ethyl Hexyl group, decyl group, etc. are mentioned.

Examples of the hydroxybenzoic acid represented by the above formula (IV) include p-hydroxybenzoic acid, m-hydroxybenzoic acid, o-hydroxybenzoic acid (salicylic acid), and those having an alkyl group having 1 to 3 carbon atoms substituted on their benzene rings. Can be.

Examples of the alkyl ester of hydroxybenzoic acid represented by the formula (V) include, for example, p-hydroxybenzoic acid methyl ester, p-hydroxybenzoic acid ethyl ester, p-hydroxybenzoic acid n-propyl ester, and the like.

The polyetherdiol is represented by HO- (YO) _n -H [Y is the same as described in the formula (II)], and is composed of repetition of linear or branched alkyl ether having 2 to 15 carbon atoms. Specifically, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. are mentioned. Polytetramethylene glycol is particularly preferred in view of availability and hydrophobicity.

The repeating number n of the ether portion of the polyetherdiol is 2 to 200, preferably 6 to 70. When n is 2 or more, the efficiency at the time of copolymerizing a phenol modified diol is good, and when n is 70 or less, there exists an advantage that the heat resistance fall of a PC copolymer is small.

The esterification reaction or transesterification reaction of hydroxybenzoic acid or its alkylester with polyetherdiol is carried out in the presence of a tin catalyst.

The amount of the tin-based catalyst is usually about 0.01 to 10% by mass, preferably about 0.05 to 5% by mass, and more preferably about 0.1 to 3% by mass relative to hydroxybenzoic acids or hydroxybenzoic acid alkyl esters. to be. By setting it as 0.01 mass% or more, sufficient reaction activity is obtained, by setting it as 10 mass% or less, a side reaction can be suppressed, and the usage-amount of the phosphoric acid aqueous solution or solid adsorbent mentioned later can be reduced, and the tin content in the phenol-modified diol obtained is more You can do less.

It is necessary to purify the phenol-modified diol obtained by such a method to reduce the tin content. Specifically, the tin content in the phenol-modified diol can be reduced by the purification method of washing the reaction tank liquid containing the phenol-modified diol with an aqueous solution of phosphoric acid or a solid adsorbent, and the interface as described above using this phenol-modified diol. By the polymerization method, the polycarbonate copolymer of the present invention having a tin content (as an element) of 0.5 ppm or less can be obtained.

In the treatment with an aqueous solution of phosphoric acid, the crude reaction product obtained in the esterification reaction or the ester exchange reaction is diluted with an organic solvent such as phosphoric acid and an immiscible organic solvent such as methylene chloride, and derived from a tin-based catalyst by liquid-liquid extraction. By extracting impurities, such as a tin compound, with a phosphoric acid layer, content in a target compound can be reduced. The concentration of the phosphoric acid aqueous solution is preferably 0.5 to 40% by mass, more preferably 1.0 to 10% by mass, most preferably 2 to 5% by mass. By making the phosphoric acid concentration 0.5 mass% or more, the extraction efficiency of impurities such as tin compounds is secured. By setting the phosphoric acid concentration to 10% by mass or less, it is possible to prevent high concentration of phosphorus-containing drainage from occurring, to protect the environment, and to prevent economic deterioration by using an aqueous solution of phosphoric acid more than necessary.

As for the capacity | capacitance of the phosphoric acid aqueous solution to be used, 26 volume% or less is preferable in a total capacity. By setting it as 26 volume% or less, the extraction efficiency of the tin compound derived from a tin-type catalyst is prevented from falling by the organic layer becoming a dispersed phase and a phosphoric acid aqueous solution at the time of liquid-liquid extraction. The tin content (as an element) in the phenol-modified diol is 10 ppm or less, preferably 5 ppm or less.

In the treatment with the solid adsorbent, the crude reaction product obtained by the esterification reaction or the transesterification reaction is diluted with an organic solvent such as methylene chloride, and the solid adsorbent is dispersed therein to adsorb impurities such as tin compounds derived from tin catalysts. Content in a target compound can be reduced.

As the solid adsorbent, a complex adsorbent composed of activated clay, acidic clay, ion exchange resin, chelate resin, activated carbon, silica magnesia alumina, or the like can be used. Commercially available products of the adsorbent include, for example, Mizukalife F-2G [manufactured by Mizuka Chemical Co., Ltd., silica / magnesia-based adsorbent], and Mizukalife P-1 [manufactured by the same company, silica-magnesia-based adsorbent] , Galleon Earth V2 [manufactured by the same company, activated clay adsorbent], Mizukaze C-1 [manufactured by the same company, silica-based adsorbent], SA-1 [Japan activated clay, product by activated clay], R15 [Japan active Clay earth product, activated clay soil adsorbent], Kyowado KW700SL [Kyoto Chemical Co., Ltd., silica alumina adsorbent], Egret A [Japan Enviro Chemicals, activated carbon adsorbent], CR 11 [Nihon Refinery products, chelate resins]. In particular, Mizukallife F-2G (manufactured by Mizu Corporation Chemical Co., Ltd.) and Mizucallife P-1 (manufactured by the same company) are preferable because of excellent adsorption performance of the tin compound.

In the case of the treatment operation by the solid adsorbent, the solid adsorbent may be charged into the column, and the crude reaction product may be passed through the packed bed to adsorb impurities such as tin compounds derived from the tin catalyst.

The method of distilling off an excess raw material (for example, hydroxybenzoic acid or its alkyl ester) can also be performed suitably by making a system pressure reduction after a reaction.

In addition, in order to remove the hydroxybenzoic acids which are impurities efficiently, you may perform extraction with the weak alkali aqueous solution as a pretreatment of the processing operation by the said phosphoric acid aqueous solution or the processing operation by a solid adsorbent.

The weak alkaline aqueous solution preferably has a pH of 8 to 11, preferably 8 to 10. If the pH is lower than 8, extraction of hydroxybenzoic acids is insufficient, and if the pH is higher than 11, the comonomer is hydrolyzed.

As said weak alkaline aqueous solution, aqueous solutions, such as hydroxide, carbonate, and hydrogencarbonate of an alkali metal (sodium, potassium, etc.) and alkaline-earth metals (magnesium, calcium, etc.), can be used.

The treatment operation by the aqueous phosphoric acid solution, the treatment operation by the solid adsorbent, and the extraction by the weak alkali aqueous solution may be performed at room temperature, or may be heated to about 30 to 40 ° C. The treatment operation with the aqueous phosphoric acid solution, the treatment operation with the solid adsorbent, and the extraction treatment with the aqueous alkali solution may be performed plural times.

In the manufacturing process of a PC copolymer, it is preferable to use a phenol modified diol as methylene chloride solution as much as possible in order to prevent the alteration etc. of it. When it cannot use as a methylene chloride solution, it can be used as aqueous alkali solution, such as NaOH.

In the PC copolymer, increasing the copolymerization amount of the phenol-modified diol improves fluidity but lowers heat resistance. Therefore, it is preferable to select the copolymerization amount of a phenol-modified diol according to the balance of desired fluidity and heat resistance. When the phenol-modified diol copolymerization amount exceeds 40 mass%, it becomes an elastomer phase as described in Unexamined-Japanese-Patent No. 1987-79222, and there exists a possibility that it cannot apply to uses, such as a general PC resin. In the present invention, the amount of the phenol-modified diol residue contained in the PC copolymer for maintaining heat resistance of 100 ° C. or higher is 1 to 30% by mass, preferably 1 to 20% by mass, more preferably 1 to 15% by mass. %to be.

The PC copolymer of the present invention has a viscosity number of 30 to 71 [corresponding to Mv (viscosity average molecular weight) = 10,000 to 28,100], preferably 37 to 62 [corresponding to Mv = 13,100 to 24,100]. The same applies to the PC copolymer composition described later. If the viscosity number is 30 or more, the mechanical properties are good, and if the viscosity number is 70 or less, the copolymerization effect of the comonomer is exhibited satisfactorily. In order to express high fluidity, a large amount of comonomer is required. However, if the viscosity number is 71 or less, the heat resistance of the use of the comonomer is not significantly reduced. In addition, a viscosity number is the value measured based on ISO1628-4 (1999).

It is preferable that the fluid value (Q value) in 280 degreeC is 30x10 <^-2> mL / sec or more, and 40 * 10 <^-2> mL / sec or more of the PC copolymer of this invention is more preferable. The flow value (Q value) is a melt viscosity measured by a high-cost flow tester in accordance with JIS K7210. When the flow value (Q value) is 30x10 ^-2 mL / sec or more, the melt viscosity of the PC copolymer is It never rises too high. The same applies to the PC copolymer composition described later.

The PC copolymer composition of this invention is a composition containing 0.01-0.5 mass part of antioxidant with respect to 100 mass parts of said PC copolymers.

As antioxidant, an aryl phosphine type, a phosphite ester type, a phosphate ester type, a hindered phenol type, etc. are mentioned.

Moreover, the PC copolymer composition of this invention may be set as the composition which mixed other PC resin whose tin content (as an element) is 0.5 ppm or less.

In addition, when using such a PC copolymer composition as a light guide plate, an optical lens, etc., it is preferable to mix | blend an acrylic resin with a molecular weight of about 1000-100,000 for the purpose of improving light transmittance, and in addition to this acrylic resin, an alicyclic epoxy It is more preferable to set it as PC type resin composition which mix | blended the polysiloxane compound which has 1 or more types chosen from a compound or an alkoxy group, a vinyl group, and a phenyl group.

As another PC resin mix | blended with the PC copolymer of this invention, PC resin whose commercially available tin content (as an element) is 0.5 ppm or less can be used. Since the compounding quantity of another PC resin does not impair the effect of this invention, 300 mass parts or less are preferable with respect to 100 mass parts of PC copolymers, and 10-200 mass parts are more preferable.

An acrylic resin means the polymer which makes at least 1 sort (s) selected from the monomeric unit of acrylic acid, acrylic acid ester, acrylonitrile, and its derivative (s) as a repeating unit, and means homopolymer or copolymer with styrene, butadiene, etc. Specifically, polyacrylic acid, polymethyl methacrylate (PMMA), polyacrylonitrile, ethyl acrylate--2-chloroethyl copolymer, acrylic acid-n-butyl-acrylonitrile copolymer, acrylonitrile -A styrene copolymer, an acrylonitrile- butadiene copolymer, an acrylonitrile- butadiene- styrene copolymer, etc. are mentioned. Among these, polymethyl methacrylate (PMMA) can be used especially suitably.

The acrylic resin has a molecular weight of about 1000 to 100,000, preferably 20,000 to 60,000. When the molecular weight is 1000 to 100,000, phase separation between the PC copolymer and other PC resins and acrylic resins is not too fast at the time of molding, so that sufficient transparency is obtained in the molded article. As a polymethyl methacrylate (PMMA), a well-known thing can be used, but what is normally manufactured by mass-polymerizing the methyl methacrylate monomer in presence of a peroxide and an azo polymerization initiator is preferable.

The compounding quantity of acrylic resin is about 0.01-1 mass part normally with respect to 100 mass parts of PC copolymer compositions which mixed another PC resin with the PC copolymer of this invention or PC copolymer of this invention, Preferably it is 0.05 To 0.5 mass part, More preferably, it is 0.1-0.3 mass part. If the compounding quantity of acrylic resin is 0.01 mass part or more, transparency of a molded article will improve, and if it is 1 mass part or less, transparency can be maintained without damaging other desired physical property.

As an alicyclic epoxy compound, the cycloaliphatic compound which has an alicyclic epoxy group, ie, the epoxy group which added one oxygen atom to the ethylene bond in an aliphatic ring, is mentioned, Specifically, following General formula (1) described in Unexamined-Japanese-Patent No. 1999-158364 What is represented by -10 is suitably used.

In formulas (2) and (3), R is a hydrogen atom or a methyl group.

In Formula 5, a and b are integers of 0-10, respectively, and a + b is an integer of 1-10.

In formula (6), a, b, c and d are each an integer of 0 to 10, and a + b + c + d is an integer of 1 to 10.

In Formula 7, a, b, and c are integers of 1-10, respectively, and a + b + c is an integer of 1-10.

In the formula (8), n is an integer of 1 to 10.

In formula (9), R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms as described above.

In formula (10), n is an integer from 1 to 10, and R is a residue of a compound having an active hydrogen group such as trimethylolpropane.

 The compounding quantity of each said alicyclic epoxy compound is about 0.01-1 mass part normally with respect to 100 mass parts of PC copolymer compositions, Preferably it is 0.02-0.2 mass part. When this compounding quantity is 0.01 mass part or more, an addition effect is acquired, and when it is 1 mass part or less, transparency can be obtained without generating phase separation.

Examples of the polysiloxane compound include organopolysiloxanes as reactive silicone compounds in which at least one functional group selected from an alkoxy group (eg, methoxy group, ethoxy group), vinyl group and phenyl group is introduced into the silicone compound. This polysiloxane compound is a compound which acts as a stabilizer in the PC resin composition. When the polysiloxane compound is blended, yellowing due to thermal deterioration at the time of molding, poor appearance such as silver (silver bath), and bubble mixing can be prevented. The compounding quantity of a polysiloxane compound is suitably selected from the range of about 0.01-3 mass parts normally, Preferably it is 0.05-2 mass parts with respect to 100 mass parts of polycarbonate copolymers. If it is 0.01 mass part or more, the effect of addition will be expressed, and if it is 3 mass parts or less, cloudyness will not arise in a molded article.

Various additives can also be mix | blended with the resin composition of this invention in the range which does not impair the effect of this invention as needed other than said each component. Examples include ultraviolet stabilizers such as benzotriazole and benzophenone, light stabilizers such as hindered amine, internal lubricants such as aliphatic carboxylic acid esters, paraffins, silicone oils and polyethylene wax, and compatible flame retardants and flame retardants and release agents. , Antistatic agents, coloring agents and the like.

Next, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited at all by these examples. In addition, the amount of impurities in each case was measured by the following method.

Preparation Example 1 Synthesis of Polytetramethylene Glycol-bis (4-hydroxybensoate)

Nitrogen was introduced into a reaction vessel having a stirrer, a thermometer, a reflux condenser, a raw material supply port, and a gas introduction tube, and 100 parts by mass of polytetramethylene glycol [PTMG, Mn (number average molecular weight) = 2000] and p-hydroxy 15.8 parts by mass of methyl benzoate and 0.05 parts by mass of dibutyltin oxide were supplied as a tin catalyst, and heated to 220 ° C to effect transesterification while distilling off the resulting methanol. After completion of the reaction, the reaction system was depressurized, and excess p-hydroxybenzoate methyl was distilled off to obtain a crude reaction product.

The crude reaction product was dissolved in methylene chloride to give a solution having a concentration of 20% by mass. 20 mol parts of 0.1 mol% sodium hydrogencarbonate aqueous solution was added to 80 volume parts of this methylene chloride solution, and it stirred and mixed for 30 minutes at 20 degreeC in the stirring tank with a baffle, and obtained p-hydroxy benzoic acid which is an impurity produced by reaction. ), And methylene chloride phase was collected by stationary separation.

25 mass parts of 3.5 mass% phosphoric acid aqueous solution was added to 75 volume parts of methylene chloride phases, and it mixed with 180 degreeC stirring for 180 minutes in the stirring tank with a baffle, and extracted the tin compound derived from a tin type catalyst by water phase, The methylene phase was collected.

Then, 25 parts by mass of 3.5 mass% phosphoric acid aqueous solution was added to 75 parts by volume of methylene chloride phase, stirred and mixed at 20 ° C. for 180 minutes in a stirring tank equipped with a baffle, and the tin compound derived from the tin catalyst was extracted with an aqueous phase, followed by stationary separation. The methylene chloride phase was collected.

To remove trace phosphoric acid in the methylene chloride phase, 25 parts by weight of pure water was added to 75 methylene chloride phase, and stirred and mixed at 20 ° C. for 60 minutes in a stirring tank equipped with a baffle to extract a tin compound derived from a tin catalyst into an aqueous phase. The methylene chloride phase was collected by stationary separation.

The methylene chloride phase was concentrated under reduced pressure to obtain polytetramethylene glycol-bis (4-hydroxybenzoate) (hereinafter briefly referred to as PTMG-BHB) as a phenol-modified diol.

According to the following HPLC (high-performance liquid chromatography), tin and phosphate ions, p-hydroxybenzoic acid in PTMG-BHB is less than 10 mass ppm, p-hydroxybenzoic acid is 0.2 mass%, tin It was confirmed that (as an element, the same below) is less than 2 ppm, and phosphorus (as an element, the same below) is 3 ppm.

Preparation Example 2 Synthesis of Polytetramethylene Glycol-bis (4-hydroxybenzoate)

PTMG-BHB was prepared in the same manner as in Production Example 1, except that polytetramethylene glycol (Mn = 1000) was used instead of Mn = 2000 PTMG and 31.6 parts by mass of methyl p-hydroxybenzoate was used. Got. According to the following HPLC (high performance liquid chromatography), tin and phosphate ions, p-hydroxybenzoic acid in PTMG-BHB is less than 10 mass ppm, p-hydroxybenzoic acid is 0.2 mass%, It was confirmed that tin was less than 2 ppm and phosphorus was less than 2 ppm.

[Production Example 3]

PTMG-BHB was obtained in the same manner as in Production Example 1, except that 1.0 mass% of phosphoric acid was used instead of 3.5 mass% of phosphoric acid. According to the following HPLC (high performance liquid chromatography), tin and phosphate ions, p-hydroxybenzoic acid in PTMC-BHB is less than 10 mass ppm, p-hydroxybenzoic acid is 0.2 mass%, It was confirmed that tin was less than 10 ppm and phosphorus was less than 2 ppm.

[Production Example 4]

PTMG-BHB was obtained in the same manner as in Production Example 1, except that 5.0 mass% phosphoric acid aqueous solution was used instead of 3.5 mass% phosphoric acid aqueous solution. According to the following HPLC (high performance liquid chromatography), tin and phosphate ions, p-hydroxybenzoic acid is less than 10 mass ppm, p-hydroxybenzoic acid is 0.2 mass%, tin is 5 ppm, phosphorus Was found to be 4 ppm.

Production Example 5

The crude reaction product was obtained in the same manner as in Example 1 until the excess methyl p-hydroxybenzoate was distilled off.

The crude reaction product was dissolved in methylene chloride to give a solution having a concentration of 20% by mass, and 5% by mass of Mizukallife F-2G (Mizuwa Chemical Co., Ltd. product) was added thereto, followed by mixing at 20 ° C for 3 hours. After adsorbing a tin compound, F-2G was filtered by vacuum filtration using a membrane filter having a pore size of 0.2 μm.

20 parts by volume of a 0.1 mol% sodium hydrogencarbonate aqueous solution was added to 80 parts by volume of the obtained methylene chloride solution, and stirred and mixed at 20 ° C. for 30 minutes in a stirrer with a baffle to prepare p-hydroxybenzoic acid, which was an impurity produced in the reaction, into an aqueous phase. After extraction, the methylene chloride phase was collected by stationary separation.

To remove traces of sodium in the methylene chloride phase, 25 parts by weight of pure water was added to 75 volumes of methylene chloride phase, and stirred at 20 ° C. for 60 minutes in a stirring tank with a baffle to extract sodium into the aqueous phase, followed by still separation of methylene chloride. The prize was taken.

The methylene chloride phase was concentrated under reduced pressure to obtain PTMG-BHB, which is a phenol-modified diol. Quantification by the following HPLC (High Performance Liquid Chromatography) and quantification of tin confirmed that the p-hydroxybenzoic acid in PTMG-BHB was less than 10 mass ppm, the p-hydroxybenzoic acid methyl was 0.2 mass%, and the tin was 5 ppm. It became.

[Manufacture example 6]

PTMG-BHB was obtained in the same manner as in Production Example 1, except that the tin compound-derived tin compound was not extracted with an aqueous phosphoric acid solution. Quantification by the following HPLC (High Performance Liquid Chromatography) and the quantitation of tin confirmed that the p-hydroxybenzoic acid in PTMG-BHB was less than 10 ppm by mass, the methyl p-hydroxybenzoate was 0.3 mass%, and the tin was 190 ppm. It became.

[Manufacture example 7]

PTMG-BHB was obtained in the same manner as in Production Example 1, except that 0.5 mass% phosphoric acid aqueous solution was used instead of 3.5 mass% phosphoric acid aqueous solution. The following HPLC (High Performance Liquid Chromatography) and tin quantification showed that p-hydroxybenzoic acid in PTMG-BHB is less than 10 mass ppm, p-hydroxybenzoic acid is 0.3 mass%, tin is 70 ppm, phosphorus is 2 ppm It was confirmed that it was less than.

<Quantification by HPLC (High Performance Liquid Chromatography)>

It quantified based on the analytical curve created by standard products of p-hydroxybenzoic acid and p-hydroxybenzoic acid by HPLC (high speed liquid chromatography) on the following conditions.

Column: ODS-3 from GL science

Column temperature: 40 ℃

Solvent: Mixture of 0.5 mass% phosphoric acid aqueous solution and acetonitrile (volume ratio 1: 2)

Flow rate: 1.0ml / min

<Quantification of Tin in Comonomer>

(1) pretreatment of samples

1.0 g of PTMG-BHB was weighed into a platinum crucible, 0.8 ml of concentrated sulfuric acid was added to the platinum crucible, and dried under heating.

0.5 g of potassium hydrogen sulfate was added and heated in a burner, and then 3 ml of 6 mol / L hydrochloric acid was added and heated to dissolve and re-dissolve the powder.

(2) measurement

After cooling the acid decomposition solution, the solution was diluted to 25 ml, and the solution obtained by diluting this further five times was subjected to ICP-OES (High Frequency Inductively Coupled Plasma Emission Spectroscopy) apparatus [SII Nanotechnology Co., Ltd.] Product, SPS 5100]. Luminescence spectroscopy analysis is based on JIS K0116.

<Determination of Tin in Polycarbonate>

(1) pretreatment of samples

3.0 g of polycarbonate was weighed into a platinum dish, 3.0 ml of concentrated sulfuric acid was added thereto, and the resultant was dried by heating and then treated at 550 ° C. for 10 hours to produce the product.

0.1 g of a compound containing lithium tetraborate anhydride and lithium fluoride in a mass ratio of 9: 1 was added thereto, and treated at 930 ° C. for 30 minutes, followed by mixing and dissolving tartaric acid aqueous solution (5 g tartaric acid, 40 ml nitric acid, and 500 ml water). 15 ml of what was added to the total volume to 1000 ml) was added, and it stirred by heating, and prepared the alkali melting solution.

(2) measurement

After cooling the alkaline solution, the solution was diluted to 25 ml, and the solution diluted 2.5 times further was quantified with an ICP-OES apparatus (SII Nanotechnology Co., Ltd. product SPS 5100). Luminescence spectroscopy is based on JIS K0116.

<Quantification of phosphorus>

10 g of PTMC-BHB was weighed out using a 200 ml Teflon (trademark) funnel.

100 ml of purified methylene chloride (* 1) was added, and PTMG-BHB was dissolved by vibration. 10 ml of pure water was added to this, and it vibrated for 30 minutes at the speed | rate of 240 times / min using the vibrator, and the phosphate ion in the sample was extracted in water.

After standing still, the organic layer and the water layer were separated, and the water layer was collected. An ion chromatograph device [Dionex corp. Product, DX-120]. Phosphoric acid standard solution was used as the standard solution.

Ion chromatography is based on JIS K0127.

Purified methylene chloride: Methylene chloride and pure water were taken in a teflon (trademark) skive funnel, and the methylene chloride was washed with pure water by vibration. This operation was performed until the pure water after extraction was analyzed by the ion chromatograph apparatus until phosphate ion was not detected. The obtained methylene chloride was used as purified methylene chloride.

Example P-1

(1) Polycarbonate (PC) oligomer synthesis process

To a 5.6 mass% sodium hydroxide aqueous solution, 2000 ppm by mass sodium adithionate was added to bisphenol A (BPA) to be dissolved later. BPA was dissolved so that the BPA concentration was 13.5 mass%, and an aqueous sodium hydroxide solution of BPA was added. Prepared. The aqueous sodium hydroxide solution of BPA was continuously passed at a flow rate of 40 l / hr and methylene chloride at a flow rate of 15 l / hr, while phosgene was continuously passed at a flow rate of 4.0 kg / hr in a tubular reactor having an inner diameter of 6 mm and a length of 30 m. . The tubular reactor had a jacket portion, and the cooling water was passed through the jacket to maintain the temperature of the reaction solution at 40 ° C or lower.

The reaction liquid sent out from the tubular reactor was continuously introduced into a 40 liter baffle water tank reactor equipped with a retreating blade. In addition, a 25 mass% sodium hydroxide aqueous solution was added to 2.8 L / hour of aqueous sodium hydroxide solution of BPA. 0.07 L / hr, 17 L / hr water, 1 mass% triethylamine aqueous solution was supplied at the flow rate of 0.64 L / hr, and reaction was carried out at 29-32 degreeC. The reaction liquid was continuously extracted from the water tank reactor, and the mixture was left still to separate and remove the aqueous phase, and a methylene chloride phase was collected. The polycarbonate oligomer solution thus obtained had an oligomer concentration of 329 g / L and a chloroformate group concentration of 0.74 mol / L.

(2) Polymerization Process of PC Copolymer

PC oligomer obtained in the synthesis step 20 l / hour, methylene chloride 12 l / hour, 40 mass% methylene chloride solution of PTMG-BHB obtained in Synthesis Example 1 868 kg / hour, 400 ml / hour 3 mass% triethylamine aqueous solution and 6.4 mass% It supplied to TK pipeline homomixer 2 SL type (manufactured by Plymix Co., Ltd.) at the flow rate of 2.3 kg / hour of sodium hydroxide aqueous solution, and prepolymerized under rotation of 3000 rpm, and obtained the prepolymerization liquid.

Subsequently, 14.1 kg / of aqueous solution which melt | dissolved BPA in 960 g / hour of 20 mass% methylene chloride solutions of this prepolymerization liquid and PTBP (p-tert- butylphenol), and a 6.4 mass% sodium hydroxide aqueous solution to the density | concentration of 8.8 mass%. The city was supplied to TK pipeline homomixer 2 SL type (manufactured by Plymix Co., Ltd.), and emulsified under rotation of 300 rpm to obtain an emulsion. Subsequently, this emulsion was introduced into a jacketed orifice mixer in which two orifice plates having three holes of 0.8 mm in diameter, which were the second reactors, were inserted into a 19.05 mm (3/4 inch) pipe. The polymerization was carried out by supplying a 50-liter paddle blade three-stage tower stirring tank with a jacket. Cooling water of 15 degreeC was flowed into the jacket, and the outlet temperature of the polymerization liquid was 30 degreeC.

A 50 L dilution tank equipped with paddle type stirring blades was continuously supplied with a polymerization liquid overflowing from the tower reactor and methylene chloride for dilution at 11 L / hr. Subsequently, the emulsion obtained from the dilution tank was introduced into a K.C.C centrifugal extractor (trade name, manufactured by Kawasaki Hollow Co., Ltd., internal volume 4L, rotor diameter 430 mm), and centrifuged at a rotational speed of 300 rpm to separate the water layer and the organic layer.

(3) alkali cleaning process

The organic layer and 0.03 mol / L sodium hydroxide aqueous solution 7.8 L / hour obtained from the said centrifugal extractor were supplied to T.K pipeline homomixer 2 SL type (made by Plymix Co., Ltd.), and stirring and mixing were performed at 3000 rpm. The mixed liquid from the homomixer outlet was introduced into a centrifugal extractor, centrifuged at a rotational speed of 3000 rpm to separate the water layer and the organic layer. Subsequently, the emulsion obtained from the dilution tank was introduced into a KCC centrifugal extractor (trade name, manufactured by Kawasaki Hollow Co., Ltd., internal volume 4L, rotor diameter 430mm), centrifuged at a rotational speed of 3000 rpm, and the water layer and the organic layer were separated. Then, it supplied to the pickling process.

(4) Pickling process

The organic layer obtained from the centrifugal extractor of an alkali washing process and 7.8 L / hour of 0.2 mol / L hydrochloric acid aqueous solution were supplied to T.K pipeline homomixer 2 SL type (made by Plymix Co., Ltd.), and stirring and mixing were performed at 3000 rpm. The mixed liquid from the homomixer outlet was introduced into the stationary separation tank to separate the water layer and the organic layer, and the organic layer was subsequently supplied to the first water washing step.

(5) 1st water washing process

The organic layer obtained from the centrifugal extractor and 7.8 L / hour of pure water were supplied to T.K pipeline homomixer 2 SL type (manufactured by Plymix Co., Ltd.), and stirred and mixed at 3000 rpm. The mixed liquid from the homomixer outlet was introduced into a centrifugal extractor, centrifuged at a rotational speed of 30 rpm to separate the water layer and the organic layer, and the organic layer was subsequently supplied to the second water washing step.

(6) 2nd water washing process

The organic layer obtained from the centrifugal extractor and 7.8 L / hour of pure water were supplied to T.K pipeline homomixer 2 SL type (manufactured by Plymix Co., Ltd.), and stirred and mixed at 300 rpm. The mixed liquid from the homomixer outlet was introduced into a centrifugal extractor, centrifuged at a rotational speed of 30OO rpm, and the water layer and the organic layer were separated to obtain a purified polycarbonate methylene chloride solution (organic layer).

(7) concentration, drying process

The purified polycarbonate methylene chloride solution was concentrated and pulverized, and the resulting plate was dried at 105 ° C under reduced pressure. The properties of the obtained polycarbonate copolymer were as follows. The amount of PTMC-BHB residue determined by NMR was 4.0 mass%. The viscosity number measured based on ISO 1628-4 (1999) was 37.0 (Mv = 13100).

Example P-2

A 40 mass% methylene chloride solution of PTMG-BHB obtained in Preparation Example 1 was replaced with 434 kg / hour of a 40 mass% methylene chloride solution of PTMG-BHB obtained in Preparation Example 2 as in Example P-1. To obtain a polycarbonate copolymer.

[Examples P-3 to P-5 and Comparative Examples P-1 and P-2]

A polycarbonate copolymer was obtained in the same manner as in Example P-1 except that PTMG-BHB obtained in Production Examples 3 to 7 was used instead of PTMG-BHB obtained in Production Example 1. Table 1 shows the physical properties of the polycarbonate copolymers obtained in Examples P-1 to P-5 and Comparative Examples P-1 and P-2.

Residue amount (mass%) Viscosity Tin content (ppm) Example p-1 4.0 37.0 <0.1 Example p-2 4.0 37.0 <0.1 Example p-3 4.0 36.9 0.4 Example p-4 4.0 37.0 0.2 Example p-5 4.0 37.0 0.2 Comparative Example p-1 4.0 36.9 7.0 Comparative Example p-2 4.0 37.0 2.5

[Application Example 1]

100 parts by mass of the polycarbonate copolymer obtained in Example P-1 and 0.05 parts by mass of Adeka staff PEP-36 (trade name, manufactured by ADEKA Co., Ltd.) were used as an antioxidant, and a resin temperature of 260 was applied by an extruder having a vent of 40 mm. Granulation was carried out at 占 폚 to obtain pellets. Using the obtained pellets, a 35 mm x 25 mm x 2 mm flat plate was injection molded under the following molding conditions.

<Molding condition>

Molding Machine: Toshiba Machine Co., Ltd., EC 40N

Molding Machine Cylinder Temperature: 340 ℃

In-cylinder retention time: 10 minutes

Five molded articles after the 13th shot were taken, and yellow index (YI) was measured using each, and the average value was calculated | required. The results are shown in Table 2. The measuring method of YI is as follows.

<YI>

A 2.0 mm-thick molded article was produced by injection molding, and the measurement area was measured with a spectrophotometer Σ90, manufactured by Nippon Denshoku Industries, Ltd., and measured by a transmission method of 30 ° and a C2 light source.

[Application Examples 2 to 5]

75 parts by mass of the polycarbonate copolymer obtained in Examples P-2 to P-5, 25 parts by mass of Teflon FN1500 (trade name, Bis-A Polycarbonate, VN = 39.5 manufactured by Idemitsu Kosan Co., Ltd.) as an antioxidant 0.05 mass parts of Adeka staff PEP-36 (brand name, product of ADEKA Co., Ltd.) was mix | blended, it granulated at the resin temperature of 260 degreeC by the extruder of 40 mm (ø) with a vent, and obtained pellet. Otherwise, YI was measured in the same manner as in Application Example 1.

[Application Comparative Examples 1 and 2]

The pellets were obtained in the same manner as in Application Example 1 except that the polycarbonate copolymers obtained in Comparative Examples P-1 to P-2 were used instead of the polycarbonate copolymers obtained in Example P-1, and YI was measured.

[Application Example 6]

75 parts by mass of the polycarbonate copolymer obtained in Example P-1 and 25 parts by mass of Teflon FN1500 (trade name, Bis-A polycarbonate manufactured by Idemitsu Petrochemical Co., Ltd., VN = 39.5) as an antioxidant 0.05 parts by mass of staff PEP-36 [brand name, product of ADEKA], 0.1 mass part of diamond BR 83 [brand name, Mitsubishi Rayon Corporation product, acrylic resin, molecular weight 40000], KR511 (brand name, Shin-Etsu Silicone ( 0.1 parts by mass of the product, organosiloxane having a methoxy group and a vinyl group, and 0.05 parts by mass of Celoxide 2021P [trade name, an alicyclic epoxy resin represented by the formula (1) of Daicel Chemical Industries, Ltd.] And pellets were granulated at a resin temperature of 260 ° C. using an extruder with a vent of 40 mm.

YI was measured like the application example 1 using the obtained pellet. YI was 0.9.

YI Application example 1 1.0 Application example 2 1.0 Application Example 3 1.1 Application Example 4 1.0 Application example 5 1.0 Application Example 6 0.9 Application Comparative Example 1 2.3 Application Comparative Example 2 1.7

The molded article of the polycarbonate copolymer with low tin content obtained by this invention can be used suitably in the field of optical members, such as a transparent optical member, especially a lens, a light guide, and an optical disk.

Claims (6)

The polycarbonate copolymer which has a repeating unit represented by following formula (I) and (II) and whose tin content (as an element) is 0.5 ppm or less. [Formula I]

[Formula II]

[R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms. X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-,- SO _2- , -O-, -CO- or any of the bonds represented by the following general formula III-1 or the following general formula III-2. [Formula III-1]

[Formula III-2]

R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms. Y represents a C2-C15 linear or branched alkylene group. a to d are each independently an integer of 0 to 4, n is an integer of 2 to 200] A method for producing a polycarbonate copolymer according to claim 1, wherein a phenol-modified diol synthesized in the presence of a tin catalyst and treated with an aqueous phosphoric acid solution or a solid adsorbent is used as a comonomer. The method of claim 2, The manufacturing method of the polycarbonate copolymer whose tin content (as an element) in the said phenol modified diol is 10 ppm or less. The polycarbonate resin composition containing 100 mass parts of polycarbonate copolymers of Claim 1, and 0.01-0.5 mass part of antioxidant. The method of claim 4, wherein The polycarbonate resin composition whose yellow index (YI) of a molded article is 1.5 or less. The molded article formed by shape | molding the resin composition of Claim 4 or 5.