JP2009280679A - Polycarbonate-based resin composition and optical molded article made of it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate-based resin composition with reduced yellowing upon molding at elevated temperatures, producing a good optical molded article; and an optical molded article made of it. <P>SOLUTION: A polycarbonate-based resin composition comprises: (A) 100 pts.mass of a polycarbonate-based resin which contains polycarbonate copolymer including predetermined amounts of repeating units represented by particular general formulas (I) and (II) and having viscosity number of 30-71; and (B) 0.0001-0.004 pts.mass of phosphoric acid. An optical molded article made of it is also disclosed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a polycarbonate resin composition, and more specifically, a polycarbonate resin composition containing a polycarbonate resin containing a polycarbonate copolymer having a specific repeating structural unit and phosphoric acid, and optical molding formed by molding the polycarbonate resin composition. Related to goods.

Polycarbonate (PC) produced from bisphenol A and the like is used in a wide range of applications because of its excellent transparency, heat resistance, mechanical properties, and the like. However, when PC is used for optical parts such as lenses, light guide plates, optical disks, etc., there is a drawback that a satisfactory molded product cannot be obtained due to low fluidity. Has been.
For example, Patent Document 1 proposes a polycarbonate copolymer obtained by copolymerizing polytetramethylene glycol-bis (4-hydroxybenzoate). Since this copolymer has remarkably improved fluidity during molding and excellent thermal stability, it can cope with a wide range of molding conditions as a molding raw material. However, when this copolymer is continuously produced, yellowing occurs during molding at a high temperature.

JP 2005-247947 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polycarbonate resin composition in which yellowing is reduced when molded at a high temperature, and as a result, a good optical molded product is obtained. is there.

  As a result of extensive research, the present inventors have obtained a specific amount of a polycarbonate-based resin containing a polycarbonate copolymer having a specific amount of a specific repeating unit and a viscosity number in a specific range, and a specific amount of phosphoric acid. It discovered that the said objective was achieved by a system resin composition. That is, when this polycarbonate-type resin composition was used as a material of an optical molded product, it discovered that yellowing generate | occur | produced when shape | molding under high temperature reduced. The present invention has been completed based on such findings.

  That is, the present invention provides the following polycarbonate resin composition and an optical molded product comprising the same.

1. (A) It has a repeating unit represented by the general formula (I) and a repeating unit represented by the general formula (II), and the content of the repeating unit represented by the general formula (II) is 1 to 30% by mass. A polycarbonate resin composition comprising 100 parts by mass of a polycarbonate resin containing a polycarbonate copolymer having a viscosity number of 30 to 71 and (B) 0.0001 to 0.004 parts by mass of phosphoric acid. .

[In the formula, R ¹ and R ² represents an alkyl group having 1 to 6 carbon atoms independently. 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 a bond represented by the following formula (III-1) or the following 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 an integer of 0 to 4, and n is an integer of 2 to 200. ]
2. In formula (II), Y _{is, -CH 2 -CH 2 -CH 2 -CH} 2 -, - CH 2 -CH 2 -CH 2 -CH (CH 3) - and -CH ₂ -CH ₂ -CH ₂ 2. The polycarbonate resin composition according to 1 above, which is one or more selected from-.
3. The polycarbonate resin composition according to 1 or 2 above, wherein the viscosity of the polycarbonate copolymer contained in the polycarbonate resin as the component (A) is 37 to 62.
4). The polycarbonate resin according to any one of 1 to 3 above, wherein a flow rate value (Q value) at 280 ° C. of the polycarbonate copolymer contained in the polycarbonate resin as the component (A) is 30 × 10 ⁻² mL / s or more. Composition.
5. (A) The polycarbonate-type resin composition in any one of said 1-4 whose polycarbonate-type resin of a component contains a polycarbonate copolymer and another polycarbonate resin.
6). The polycarbonate resin according to any one of 1 to 5 above, further comprising 0.01 to 1 part by mass of (C) an acrylic resin having a molecular weight of 200 to 100,000 with respect to 100 parts by mass of the polycarbonate resin as the component (A). Composition.
7). (A) One or more kinds selected from (D) 0.01 to 1 part by mass of an alicyclic epoxy compound and / or (E) an alkoxy group, a vinyl group, and a phenyl group with respect to 100 parts by mass of the polycarbonate-based resin of the component The polycarbonate-type resin composition in any one of said 1-6 containing 0.01-3 mass parts of polysiloxane compounds which have this.
8). 8. An optical molded article comprising the polycarbonate resin composition according to any one of 1 to 7 above.
9. 9. The optically molded product as described in 8 above, which is a light guide plate.
10. 9. The optical molded product according to 8 above, which is a lens.

  The polycarbonate resin composition of the present invention containing a polycarbonate resin containing a specific polycarbonate copolymer and phosphoric acid can reduce yellowing when the resin composition is molded under high temperature, and is a durability test. Therefore, it is suitable for an optical molded product formed by molding the resin composition.

  The polycarbonate resin composition of the present invention comprises (A) a specific polycarbonate resin and (B) phosphoric acid as essential components, (C) an acrylic resin, (D) an alicyclic epoxy compound, and (E) a specific resin. It can contain a polysiloxane compound.

[(A) Polycarbonate resin]
In the polycarbonate resin composition of the present invention, the polycarbonate copolymer contained in the polycarbonate resin of the component (A) (hereinafter sometimes abbreviated as “PC copolymer”) is a phenol-modified diol copolymer polycarbonate. And can be produced by a conventional production method called an interfacial polymerization method. That is, it can be produced by a method of reacting carbonate precursors such as dihydric phenol, phenol-modified diol and phosgene. Specifically, for example, in an inert solvent such as methylene chloride, in the presence of a known acid acceptor or molecular weight regulator, a catalyst or a branching agent is added as necessary, and dihydric phenol, phenol-modified diol and phosgene are added. And a carbonate precursor such as
Further, the PC copolymer has repeating units represented by the following general formulas (I) and (II).

（式中、Ｒ¹〜Ｒ⁴、Ｘ、Ｙ、ａ〜ｄ及びｎについては後述する。）

(In the formula, R ^{1 to} R ⁴ , X, Y, ad, and n will be described later.)

<Dihydric phenol>
Examples of the dihydric phenol include compounds represented by the following general formula (Ia).

In the general formula (Ia), R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms, and the alkyl group may be linear, branched or cyclic. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, and an isohexyl group. , Cyclopentyl group, cyclohexyl group and the like. a and b each represent the number of substitutions of R ¹ and R ² and are integers of 0 to 4. Incidentally, when R ¹ are a plurality of multiple R ¹ may be the same or different, when R ² are a plurality, the plurality of R ² may be the same or different from each other.

X is a single bond, an alkylene group having 1 to 8 carbon atoms (for example, methylene group, ethylene group, propylene group, butylene group, pentylylene group, hexylene group, etc.), an alkylidene group having 2 to 8 carbon atoms (for example, ethylidene group, isopropylidene group). Group), a cycloalkylene group having 5 to 15 carbon atoms (eg, cyclopentylene group, cyclohexylene group, etc.), a cycloalkylidene group having 5 to 15 carbon atoms (eg, cyclopentylidene group, cyclohexylidene group, etc.),- S—, —SO—, —SO ₂ —, —O—, —CO— bond or a bond represented by the following formula (III-1) or the following formula (III-2) is shown.

  There are various dihydric phenols represented by the general formula (Ia), and 2,2-bis (4-hydroxyphenyl) propane [common name: bisphenol A] is particularly preferable. Examples of bisphenols other than bisphenol A include bis (hydroxyaryl) alkanes, bis (hydroxyaryl) cycloalkanes, dihydroxyaryl ethers, dihydroxydiaryl sulfides, dihydroxydiaryl sulfoxides, dihydroxydiaryl sulfones, dihydroxydiphenyls , Dihydroxydiarylfluorenes, dihydroxydiaryladamantanes, and others, bis (4-hydroxyphenyl) diphenylmethane, 4,4 ′-[1,3-phenylenebis (1-methylethylidene)] bisphenol, 10,10-bis (4 -Hydroxyphenyl) -9-anthrone, 1,5-bis (4-hydroxyphenylthio) -2,3-dioxapentaene and α, ω-bishydroxyphene Nyl polydimethylsiloxane compounds and the like. These dihydric phenols may be used alone or in combination of two or more.

<Phenol-modified diol>
Examples of the phenol-modified diol include compounds represented by the following general formula (IIa).

In the general formula (IIa), R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms, and specific examples include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. If there are a plurality of R ^3, a plurality of R ³ may be the same or different from each other, if R ⁴ is plural, R ⁴ may be the same or different from each other.
Y represents a linear or branched alkylene group having 2 to 15 carbon atoms, specifically an alkylene group such as an ethylene group, a propylene group, a butylene group, an isobutylene group, a pentylene group and an isopentylene group; an ethylidene group, a propylidene group And alkylidene groups such as isopropylidene group, butylidene group, isobutylidene group, pentylidene group and isopentylidene group. Among _{these, -CH 2 -CH 2 -CH 2 -CH} 2 -, - CH 2 -CH 2 -CH 2 -CH (CH 3) - and -CH ₂ -CH ₂ -CH ₂ - one selected from The above is preferable.
c and d are each independently an integer of 0 to 4. n is 2-200, Preferably it is 6-70.

  The phenol-modified diol represented by the general formula (IIa) is, for example, a compound derived from hydroxybenzoic acid or an alkyl ester thereof, an acid chloride and a polyether diol. This phenol-modified diol can be synthesized by the methods proposed in JP-A-62-79222, JP-A-60-79072, JP-A-2002-173465, and the like. It is desirable to appropriately purify the phenol-modified diol obtained by the above. Examples of the purification method include a method in which the pressure in the system is reduced in the latter stage of the reaction, and excess raw materials (for example, parahydroxybenzoic acid) are distilled off. The method of washing with is desirable.

  Examples of hydroxybenzoic acid alkyl esters include hydroxybenzoic acid methyl ester and hydroxybenzoic acid ethyl ester. The polyether diol is represented by HO— (Y—O) n—H (Y and n are the same as described above), and is a repeating group consisting of a linear or branched oxyalkylene group having 2 to 15 carbon atoms. It has a unit. Specific examples include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Polytetramethylene glycol is particularly preferable from the viewpoints of availability and hydrophobicity. When the repeat number n of the oxyalkylene group of the polyether diol is 2 or more, the efficiency when copolymerizing the phenol-modified diol is high, and when n is 200 or less, the heat resistance of the component (A) is small. There is an advantage.

  Representative examples of acid chlorides are those obtained from hydroxybenzoic acid and phosgene. More specifically, it can be obtained by the method described in Japanese Patent No. 2652707. Hydroxybenzoic acid or an alkyl ester thereof may be any of a para isomer, a meta isomer, and an ortho isomer, but the para isomer is preferable from the viewpoint of the copolymerization reaction. Ortho forms may be inferior in copolymerization reactivity due to steric hindrance to hydroxyl groups.

In the production process of the PC copolymer contained in the component (A), the phenol-modified diol is preferably used as a methylene chloride solution as much as possible in order to prevent its alteration. When it cannot be used as a methylene chloride solution, it can be used as an alkaline aqueous solution such as sodium hydroxide.
In the PC copolymer, if the amount of the phenol-modified diol is increased, the fluidity is improved, but the heat resistance is lowered. Therefore, the copolymerization amount of the phenol-modified diol is preferably selected according to the desired balance between fluidity and heat resistance. When the amount of the phenol-modified diol copolymerized is too large, as shown in JP-A-62-79222, it becomes elastomeric and may not be applicable to the same use as a general polycarbonate resin. In order to maintain heat resistance of 100 ° C. or more, the amount of the repeating unit represented by the general formula (II) contained in the PC copolymer, that is, the phenol-modified diol residue is 1 to 30% by mass, Preferably it is 1-20 mass%, More preferably, it is 1-15 mass%.

<Molecular weight regulator>
Any molecular weight regulator can be used without particular limitation as long as it is usually used for polymerization of polycarbonate 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-cyclohexylphenol, 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 2,4-di-t-butylphenol; 3,5-di-t-butylphenol; 2,5-dicumylphenol; 3,5-dicumylphenol; p-cresol, bromophenol, tribromo Phenol, monoalkylphenol having a linear or branched alkyl group having an average carbon number of 12 to 35 in the ortho position, meta position or para position; 9- (4-hydroxyphenyl) -9- (4-methoxyphenyl) fluorene 9- (4-hydroxy-3-methylphenyl) -9- (4-methoxy-3-methylphenyl); Le) fluorene; 4- (1-adamantyl) phenol and the like. Among these, pt-butylphenol, p-phenylphenol, p-cumylphenol and the like are preferably used.

<catalyst>
As the catalyst, phase transfer catalysts such as tertiary amines or salts thereof, quaternary ammonium salts and quaternary phosphonium salts can be preferably used.
Examples of tertiary amines include triethylamine, tributylamine, N, N-dimethylcyclohexylamine, pyridine and dimethylaniline. Examples of tertiary amine salts include hydrochlorides and bromates of these tertiary amines. Etc. Examples of the quaternary ammonium salt include trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, and tetrabutylammonium bromide. Examples of the quaternary phosphonium salt include tetrabutylphosphonium chloride and tetrabutylphosphonium bromide. These catalysts may be used alone or in combination of two or more. Of these, tertiary amines are preferable, and triethylamine is particularly preferable.

<Inert organic solvent>
There are various kinds of inert organic solvents. For example, 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 and chlorobenzene, and the like; and toluene and acetophenone. These organic solvents may be used alone or in combination of two or more. Of these, methylene chloride is particularly preferred.

<Branching agent>
Examples of the branching agent include 1,1,1-tris (4-hydroxyphenyl) ethane, 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl]. Ethylidene] bisphenol, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl] -4 A compound having three or more functional groups such as [α ′, α′-bis (4 ″ -hydroxyphenyl) ethyl] benzene, phloroglucin, trimellitic acid and isatin bis (o-cresol) can be used.

<Viscosity number>
In the present invention, the PC copolymer contained in the component (A) has a viscosity number of 30 to 71 [equivalent to Mv (viscosity average molecular weight) = 10,000 to 28,100], preferably 37 to 62 [ Mv = 12,000 to 24,100 equivalent]. When the viscosity number is 30 or more, the mechanical properties are good, and when the viscosity number is 71 or less, the copolymerization effect of the phenol-modified diol (comonomer) is exhibited well.
In addition, a large amount of comonomer is required to exhibit high fluidity, but when the viscosity number is 71 or less, the heat resistance does not greatly decrease with respect to the amount of comonomer used. The viscosity number is a value measured according to ISO 1628-4 (1999).

<Flow value (Q value)>
The PC copolymer contained in the component (A) preferably has a flow value (Q value) at 280 ° C. of 30 × 10 ⁻² mL / s or more, and 40 × 10 ⁻² mL / s or more. More preferred. The flow value (Q value) is a melt viscosity measured with an elevated flow tester in accordance with JIS K 7210. When the flow value (Q value) is 30 × 10 ⁻² mL / s or more, (A ) The melt viscosity of the component does not become too high.

As the component (A) of the present invention, only the PC copolymer can be used as a material for various optical molded products, but other polycarbonate resins may be mixed with the PC copolymer.
Other polycarbonate resins are not particularly limited as long as the object of the present invention is not impaired, and commercially available polycarbonate resins can be used. The blending amount is usually preferably 300 parts by mass or less and more preferably 10 to 200 parts by mass with respect to 100 parts by mass of the PC copolymer.

[(B) Phosphoric acid]
In the polycarbonate resin composition of the present invention, yellowing and discoloration can be reduced by molding the resin composition by adding phosphoric acid. From the viewpoint of operation, it is preferable to use phosphoric acid dissolved in water so as to be 0.1 to 10% by mass.
(B) The compounding quantity of a component is 0.0001-0.004 mass part with respect to 100 mass parts of (A) component. If it is less than 0.0001 part by mass, the yellowing improvement effect cannot be satisfactorily exhibited, and if it exceeds 0.004 part by mass, discoloration occurs when exposed to a heated atmosphere for a long time. More preferably, it is 0.0005-0.0016 mass part, More preferably, it is 0.0006-0.0016 mass part.

[(C) Acrylic resin]
The polycarbonate-type resin composition of this invention can mix | blend (C) acrylic resin.
As the component (C), for example, a polymer having a repeating unit of at least one selected from monomer units of acrylic acid, acrylic ester, acrylonitrile and derivatives thereof, a homopolymer or styrene, butadiene, α-olefin, vinyl chloride Etc. and a copolymer. Specifically, polyacrylic acid, polymethyl methacrylate (PMMA), polyacrylonitrile, ethyl acrylate-acrylic acid-vinyl chloride copolymer, acrylic acid-n-butene-acrylonitrile copolymer, acrylonitrile-styrene copolymer And acrylonitrile-butadiene copolymer and acrylonitrile-butadiene-styrene copolymer. Among these, PMMA can be particularly preferably used. As the PMMA, known ones can be used, but usually those produced by bulk polymerization of a methyl methacrylate monomer in the presence of a peroxide or an azo polymerization initiator are preferred.

The component (C) preferably has a molecular weight of 200 to 100,000, more preferably 20,000 to 60,000. When the molecular weight is 200 to 100,000, the phase separation between the component (A) and the acrylic resin does not become too fast during molding, so that sufficient transparency can be obtained in the molded product.
(C) The compounding quantity of a component is about 0.01-1 mass part normally with respect to 100 mass parts of (A) component. When the blending amount of the acrylic resin is 0.01 parts by mass or more, the transparency of the molded product is improved, and when it is 1 part by mass or less, the transparency can be maintained without impairing other desired physical properties. . Preferably it is 0.05-0.5 mass part, More preferably, it is 0.1-0.3 mass part.

[(D) Alicyclic epoxy compound]
The polycarbonate-type resin composition of this invention can mix | blend (D) alicyclic epoxy compound.
The component (D) refers to a cycloaliphatic compound having an epoxy group in which one oxygen atom is added to an ethylene bond in an aliphatic ring. Specifically, the following formula (shown in JP-A-11-158364) ( Those represented by 1) to (10) are preferably used.

（Ｒ：Ｈ又はＣＨ₃）

(R: H or CH ₃ )

（Ｒ：Ｈ又はＣＨ₃）

(R: H or CH ₃ )

（ａ＋ｂ＝１又は２）

(A + b = 1 or 2)

（ａ＋ｂ＋ｃ＋ｄ＝１〜３）

(A + b + c + d = 1-3)

（ａ＋ｂ＋ｃ＝ｎ（整数）、Ｒ：炭化水素基）

(A + b + c = n (integer), R: hydrocarbon group)

（ｎ：整数）

(N: integer)

（Ｒ：炭化水素基）

(R: hydrocarbon group)

（ｎ：整数、Ｒ：炭化水素基）

(N: integer, R: hydrocarbon group)

Among the alicyclic epoxy compounds, the compound represented by the formula (1), formula (7) or formula (10) is excellent in compatibility with the PC resin of the component (A) and impairs transparency. It is more preferably used in that there is no.
(D) The compounding quantity of a component is about 0.01-1 mass part normally with respect to 100 mass parts of (A) component. The effect of improving hydrolysis resistance can be expressed by setting it to 0.01 parts by mass or more, and by setting it to 1 part by mass or less, phase separation is not promoted and an improvement in transparency is obtained. It is done. Preferably it is 0.02-0.2 mass part.

[(E) Polysiloxane compound]
The polycarbonate-type resin composition of this invention can mix | blend the polysiloxane compound which has 1 or more types chosen from (E) alkoxy group, a vinyl group, and a phenyl group.
Examples of the alkoxy group include a methoxy group and an ethoxy group. (E) A component is a reactive silicone type compound, and organopolysiloxane etc. are mentioned. This (E) component is a compound that acts as a stabilizer. When the (E) component is blended, it can prevent yellowing due to thermal deterioration during molding, appearance defects such as silver (silver strip), and mixing of bubbles. it can.
(E) The compounding quantity of a component is about 0.01-3 mass parts normally with respect to 100 mass parts of (A) component. When it is 0.01 part by mass or more, the effect can be exhibited, and when it is 3 parts by mass or less, the molded product does not become cloudy. Preferably it is 0.05-2 mass parts.

[Additive]
In addition to the above components (A) to (E), various additives may be blended with the polycarbonate-based resin composition of the present invention as necessary within a range not impairing the effects of the present invention. Various additives include, for example, arylphosphine-based, other phosphite-based, phosphate-based and hindered phenol-based antioxidants, benzotriazole-based and benzophenone-based ultraviolet absorbers, hindered amine-based, etc. Light stabilizers, aliphatic carboxylic acid ester compounds, paraffin compounds, internal lubricants such as silicone oil and polyethylene wax, conventional flame retardants, flame retardant aids, mold release agents, antistatic agents and colorants Etc.

[Optical molded products]
The present invention also provides an optical molded article that is a molded article for optical use comprising the polycarbonate resin composition. There are no particular restrictions on the method for producing the optical molded product of the present invention, and various conventionally known molding methods such as injection molding, injection compression molding, extrusion molding, blow molding, press molding, vacuum molding, and foam molding. The method etc. can be used. As the optically molded product, a light guide plate and a lens are preferably mentioned.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Production Example 1 [Synthesis of polytetramethylene glycol-bis (4-hydroxybenzoate)]
In a nitrogen atmosphere, 100 parts by mass of polytetramethylene glycol (PTMG, Mn (number average molecular weight) = 1000) and 33.4 parts by mass of methyl p-hydroxybenzoate were added at 220 ° C. in the presence of 0.05 part by mass of dibutyltin oxide. And methanol was distilled off.
The reaction system was depressurized, and excess methyl p-hydroxybenzoate was distilled off. 5.0 parts by mass of the reaction product was dissolved in 30 parts by volume of methylene chloride. To this methylene chloride solution, 10 parts by volume of an 8% by mass aqueous sodium hydrogen carbonate solution was added, vigorously mixed for 20 minutes, and then the methylene chloride phase was collected by centrifugation. The methylene chloride phase was concentrated under reduced pressure to obtain polytetramethylene glycol-bis (4-hydroxybenzoate) which is a phenol-modified diol. As a result of quantifying p-hydroxybenzoic acid and methyl p-hydroxybenzoate in polytetramethylene glycol-bis (4-hydroxybenzoate) by the following method by HPLC (high performance liquid chromatography), p-hydroxybenzoic acid was obtained. Was less than 10 mass ppm, and methyl p-hydroxybenzoate was 0.2 mass%.

<Quantification of p-hydroxybenzoic acid and methyl p-hydroxybenzoate>
Quantification was performed by HPLC (high performance liquid chromatography) under the following conditions based on a calibration curve prepared with a standard product.
Column: OD Science ODS-3
Column temperature: 40 ° C
Solvent: 0.5% by mass phosphoric acid aqueous solution and acetonitrile volume ratio 1: 2 mixture Flow rate: 1.0 ml / min

Production Example 2 (Production of PC copolymer)
(1) PC oligomer synthesis step To a 5.6 mass% sodium hydroxide aqueous solution, 2000 mass ppm of sodium dithionite is added to bisphenol A (BPA) to be dissolved later, and the BPA concentration is 13.5. BPA was dissolved so as to have a mass%, and an aqueous sodium hydroxide solution of BPA was prepared. A sodium hydroxide aqueous solution of BPA was continuously passed through a tubular reactor having an inner diameter of 6 mm and a pipe length of 30 m at a flow rate of 40 L / hr and methylene chloride at a flow rate of 15 L / hr, and phosgene was continuously supplied at a flow rate of 4.0 kg / hr. Passed through. The tubular reactor had a jacket portion, and the temperature of the reaction solution was kept at 40 ° C. or lower by passing cooling water through the jacket.
The reaction liquid sent out from the tubular reactor was continuously introduced into a 40-liter baffled tank reactor equipped with a receding blade, and further BPA sodium hydroxide aqueous solution was added at 2.8 L / hr, A 25% by mass sodium hydroxide aqueous solution was supplied at a flow rate of 0.07 L / hr, water at 17 L / hr, and a 1% by mass triethylamine aqueous solution at a flow rate of 0.64 L / hr, and the reaction was performed at 29 to 32 ° C. The reaction liquid was continuously extracted from the tank reactor and allowed to stand to separate and remove the aqueous phase, and the 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) PC copolymer polymerization step (1) PC oligomer 20L / hr obtained in the synthesis step, methylene chloride 12L / hr, polytetramethylene glycol-bis (4-hydroxybenzoate) obtained in Production Example 1 ) 40 mass% methylene chloride solution 868 kg / hr, 3 mass% triethylamine aqueous solution 400 ml / hr and 6.4 mass% sodium hydroxide aqueous solution 2.3 kg / hr. It supplied to K pipeline homomixer 2SL type [made by Primix Co., Ltd.], and it preliminarily polymerized under rotation of 3000 rpm, and the prepolymerization liquid was obtained.
Subsequently, BPA was dissolved in 960 g / hr of a 20 mass% methylene chloride solution of PTBP (p-tert-butylphenol) and PTBP (p-tert-butylphenol) in a 6.4 mass% aqueous sodium hydroxide solution to a concentration of 8.8 mass%. Of aqueous solution 14.1 kg / hr. It supplied to K pipeline homomixer 2SL type [made by Primix Co., Ltd.], and it emulsified under rotation of 3000 rpm, and obtained the 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 are the second reactor, were inserted into a 19.05 mm (3/4 inch) pipe, Further, as a third reactor, a 50 L paddle blade-equipped three-stage tower-type stirring tank with a jacket was supplied for polymerization. Cooling water at 15 ° C. was allowed to flow through the jacket, and the outlet temperature of the polymerization liquid was set to 30 ° C.
Into a 50 L dilution tank equipped with a paddle type stirring blade, a polymerization liquid overflowing from the column reactor and methylene chloride for dilution were continuously supplied at 11 L / hr. The emulsion obtained from the dilution tank is C. The mixture was introduced into a C centrifugal extractor [trade name, manufactured by Kawasaki Heavy Industries, Ltd., internal volume: 4 L, rotor diameter: 430 mm] and subjected to centrifugal extraction at a rotational speed of 3000 rpm to separate an aqueous layer and an organic layer.

(3) Alkaline washing step The organic layer obtained from the above centrifugal extractor and 0.03 mol / L aqueous sodium hydroxide solution (7.8 L / hr) were added to T.C. It supplied to K pipeline homomixer 2SL type [made by Primix Co., Ltd.], and was stirred and mixed at 3000 rpm. The liquid mixture from the outlet of the homomixer was introduced into a centrifugal extractor, and centrifugal extraction was performed at a rotational speed of 3000 rpm to separate the aqueous layer and the organic layer.
The emulsion obtained from the dilution tank is C. C Centrifugal extractor [trade name, manufactured by Kawasaki Heavy Industries, Ltd., internal volume: 4L, rotor diameter: 430mm] and centrifugal extraction at a rotational speed of 3000rpm to separate the aqueous layer and the organic layer, and the organic layer is a continuous acid It was supplied to the washing process.
(4) Acid washing process The organic layer obtained from the centrifugal extractor in the alkali washing process and 7.8 L / hr of 0.2 mol / L hydrochloric acid aqueous solution were treated with T.P. It supplied to K pipeline homomixer 2SL type [made by Primix Co., Ltd.], and was stirred and mixed at 3000 rpm. The liquid mixture from the outlet of the homomixer was introduced into a stationary separation tank to separate the aqueous layer and the organic layer, and the organic layer was supplied to the subsequent first water washing step.

(5) First water washing step An organic layer obtained from a centrifugal extractor and 7.8 L / hr of pure water were treated with T.W. It supplied to K pipeline homomixer 2SL type [made by Primix Co., Ltd.], and was stirred and mixed at 3000 rpm. The mixed solution from the homomixer outlet was introduced into a centrifugal extractor, and centrifugal extraction was performed at a rotational speed of 3000 rpm to separate the aqueous layer and the organic layer. The organic layer was supplied to the subsequent second water washing step.
(6) Second water washing step The organic layer obtained from the centrifugal extractor and 7.8 L / hr of pure water were treated with T.W. It supplied to K pipeline homomixer 2SL type [made by Primics Co., Ltd.], and was stirred and mixed at 3000 rpm. The mixed solution from the outlet of the homomixer was introduced into a centrifugal extractor and subjected to centrifugal extraction at a rotational speed of 3000 rpm to separate the aqueous layer and the organic layer, thereby obtaining a purified polycarbonate methylene chloride solution (organic layer).
(7) Concentration and drying step The purified polycarbonate methylene chloride solution was concentrated and pulverized, and the obtained flakes were dried at 105 ° C under reduced pressure. The properties of the obtained polycarbonate flakes were as follows.
The amount of polytetramethylene glycol-bis (4-hydroxybenzoate) residue determined by NMR was 4.0% by mass.
The viscosity number measured according to ISO 1628-4 (1999) was 36.9 (Mv = 13000). The flow value (Q value) measured by the following method was 96 × 10 ⁻² mL / s. The BPA content was 130 ppm, the methylene chloride content was 1300 ppm, the chloride ion content was less than 0.3 ppm, and the sodium content was less than 0.1 ppm.

<Flow value (Q value)>
Using an elevated flow tester, the amount of molten resin (mL / sec) flowing out from a nozzle having a diameter of 1 mm and a length of 10 mm was measured under a pressure of 280 ° C. and 15.7 MPa according to JIS K 7210. The flow value (Q value) increases with decreasing melt viscosity.

[Examples 1 to 5]
(A) 75 parts by mass of the polycarbonate copolymer obtained in Production Example 2 as a component and 25 parts by mass of Taflon FN 1500 [trade name, manufactured by Idemitsu Kosan Co., Ltd., bis-A polycarbonate, viscosity number: 39.5], (B ) 1.3% by mass phosphoric acid aqueous solution as a component as shown in Table 1, and 0.05 parts by mass of ADEKA STAB PEP-36 [trade name, manufactured by ADEKA Co., Ltd.] as an antioxidant, respectively, and 40 mmφ with vent Was pelletized at a resin temperature of 260 ° C. using an extruder.
Using the obtained pellets, an injection molding machine EC40N [trade name, Toshiba Machine Co., Ltd.] was used to mold a molded product (flat plate: 35 mm × 25 mm × 2 mm) under conditions of a cylinder temperature of 340 ° C. and a residence time of 8 minutes, The yellow index (YI) was measured by the following method. The measurement results are shown in Table 1.

Yellow index (YI)
YI (A): Five molded products after the 13th shot were prepared, and measured with a spectrocolorimeter Σ90 manufactured by Nippon Denshoku Industries Co., Ltd., with a measurement area of 30φ and a C2 light source transmission method, and the average value was obtained. .
YI (B): Five YI (A) molded products were left in an oven at 80 ° C. for 500 hours, and then YI was measured in the same manner as YI (A) to obtain an average value.

[Example 6]
(A) 75 parts by mass of the polycarbonate copolymer obtained in Production Example 2 as a component and 25 parts by mass of Taflon FN 1500 [trade name, manufactured by Idemitsu Kosan Co., Ltd., bis-A polycarbonate, viscosity number: 39.5], (B ) 1.3 mass% phosphoric acid aqueous solution 0.06 parts by mass as component, and (C) component DIANAL BR83 [trade name, Mitsubishi Rayon Co., Ltd., acrylic resin, molecular weight: 40000] 0.1 parts by mass, (D ) Celoxide 2021P [trade name, Daicel Chemical Industries, Ltd.] 0.05 part by mass as component; KR511 [trade name, manufactured by Shin-Etsu Silicone Co., Ltd., organosiloxane having methoxy group and vinyl group] as component (E) 0.1 0.05 parts by mass of Adeka Stab PEP-36 [trade name, manufactured by ADEKA Corporation] as an antioxidant It is blended to obtain a granulated pellets at a resin temperature of 260 ° C. by an extruder with a vent 40 mm diameter. Using the obtained pellets, YI (A) and YI (B) were measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[Comparative Example 1]
(B) YI (A) and YI (B) were measured in the same manner as in Example 1 except that no 1.3 mass% phosphoric acid aqueous solution was added. The measurement results are shown in Table 1.
[Comparative Example 2]
(B) Except not using 1.3 mass% phosphoric acid aqueous solution, and using 0.085 mass parts of Adeka Stub HP-10 [trade name, manufactured by ADEKA Corporation] instead of Adeka Stub PEP-36 as an antioxidant. Was carried out in the same manner as in Example 1, and YI (A) and YI (B) were measured. The measurement results are shown in Table 1.

[Comparative Examples 3 and 4]
(B) Except having shown the compounding quantity of 1.3 mass% phosphoric acid aqueous solution in Table 1, it carried out similarly to Example 1 and measured YI (A) and YI (B). The measurement results are shown in Table 1.
[Comparative Example 5]
(B) YI (A) and YI (B) were measured in the same manner as in Example 1 except that 0.05 parts by mass of 1.3% by mass phosphonic acid aqueous solution was used instead of 1.3% by mass phosphoric acid aqueous solution. did. The measurement results are shown in Table 1.
[Comparative Example 6]
(B) A molded product was obtained in the same manner as in Example 1 except that 0.04 part by mass of a 1.3% by mass aqueous phosphinic acid solution was used instead of the 1.3% by mass phosphoric acid aqueous solution. In the obtained molded product, since resin decomposition progressed during molding, it was impossible to measure YI (A) and YI (B).

  According to the polycarbonate-based resin composition of the present invention, when molded at a high temperature, yellowing is reduced, and a molded product with reduced discoloration in a durability test can be obtained. It is suitable for optical molded products, particularly light guide plates and lenses.

Claims (10)

(A) It has a repeating unit represented by the general formula (I) and a repeating unit represented by the general formula (II), and the content of the repeating unit represented by the general formula (II) is 1 to 30% by mass. A polycarbonate resin composition comprising 100 parts by mass of a polycarbonate resin containing a polycarbonate copolymer having a viscosity number of 30 to 71 and (B) 0.0001 to 0.004 parts by mass of phosphoric acid. .

[In the formula, R ¹ and R ² represents an alkyl group having 1 to 6 carbon atoms independently. 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 a bond represented by the following formula (III-1) or the following 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 an integer of 0 to 4, and n is an integer of 2 to 200. ] In formula (II), Y _{is, -CH 2 -CH 2 -CH 2 -CH} 2 -, - CH 2 -CH 2 -CH 2 -CH (CH 3) - and -CH ₂ -CH ₂ -CH ₂ The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin composition is one or more selected from −.   The polycarbonate resin composition according to claim 1 or 2, wherein the polycarbonate copolymer contained in the polycarbonate resin as the component (A) has a viscosity number of 37 to 62. The polycarbonate-based resin according to any one of claims 1 to 3, wherein the polycarbonate copolymer contained in the polycarbonate-based resin (A) has a flow value (Q value) at 280 ° C of 30 × 10 ^-2 mL / s or more. Resin composition.   The polycarbonate-based resin composition according to any one of claims 1 to 4, wherein the polycarbonate-based resin (A) contains a polycarbonate copolymer and another polycarbonate resin.   The polycarbonate system according to any one of claims 1 to 5, further comprising (C) 0.01 to 1 part by mass of an acrylic resin having a molecular weight of 200 to 100,000 with respect to 100 parts by mass of the component (A) polycarbonate resin. Resin composition.   (A) One or more kinds selected from (D) 0.01 to 1 part by mass of an alicyclic epoxy compound and / or (E) an alkoxy group, a vinyl group, and a phenyl group with respect to 100 parts by mass of the polycarbonate-based resin of the component The polycarbonate-type resin composition in any one of Claims 1-6 containing 0.01-3 mass parts of polysiloxane compounds which have this.   An optical molded article comprising the polycarbonate resin composition according to claim 1.   The optical molded product according to claim 8 which is a light guide plate.   The optical molded article according to claim 8 which is a lens.