WO2018139206A1

WO2018139206A1 - Polycarbonate resin composition for optical parts and optical part

Info

Publication number: WO2018139206A1
Application number: PCT/JP2018/000555
Authority: WO
Inventors: 恵介冨田
Original assignee: 三菱エンジニアリングプラスチックス株式会社
Priority date: 2017-01-26
Filing date: 2018-01-12
Publication date: 2018-08-02
Also published as: JPWO2018139206A1; JP6446601B1

Abstract

The present invention is a polycarbonate resin composition for optical parts and an optical part, which have a good hue and very little gas generation and mold contamination during molding. The polycarbonate resin composition for optical parts is characterized in containing, with respect to 100 parts by mass of a polycarbonate resin (A): 0.1-4 parts by mass of a polyalkylene glycol (B) that has a weight average molecular weight (Mw), measured in a tetrahydrofuran solvent by gel permeation chromatography and calculated as polystyrene, of greater than 4,000-7,700 and has a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 2.5 or less; and 0.005-0.5 parts by mass of a phosphorus stabilizing agent (C).

Description

Polycarbonate resin composition for optical parts and optical parts

The present invention relates to a polycarbonate resin composition for optical parts and an optical part, and more specifically, a polycarbonate resin composition for optical parts having a good hue and extremely low gas generation and mold contamination during molding, and molding the same. Related to the optical component.

2. Description of the Related Art A liquid crystal display device used in personal computers, mobile phones, and the like has a surface light source device incorporated in order to meet the demands for thinning, lightening, labor saving, and high definition. The surface light source device has a wedge-shaped cross-section light guide plate or a flat plate shape with a uniform inclined surface for the purpose of uniformly and efficiently guiding incident light to the liquid crystal display side. A light guide plate is provided. In some cases, an uneven pattern is formed on the surface of the light guide plate to provide a light scattering function.

Such a light guide plate is obtained by injection molding of a thermoplastic resin, and the above concavo-convex pattern is imparted by transferring the concavo-convex portion formed on the surface of the nest. Conventionally, the light guide plate has been molded from a resin material such as polymethylmethacrylate (PMMA). Recently, however, a display device that displays a clearer image has been demanded, and the temperature inside the device is increased by heat generated near the light source. Therefore, it is being replaced with a polycarbonate resin material having higher heat resistance.

Polycarbonate resin is excellent in mechanical properties, thermal properties, electrical properties, and weather resistance, but its light transmittance is lower than that of PMMA, etc., so that a surface light source body is formed from a light guide plate made of polycarbonate resin and a light source. When configured, there is a problem that the luminance is low. Recently, it has been demanded to reduce the difference in chromaticity between the light incident portion of the light guide plate and the location away from the light incident portion, but there is a problem that the polycarbonate resin is more easily yellowed than PMMA.

Patent Document 1 discloses a method for improving light transmittance and luminance by adding an acrylic resin and an alicyclic epoxy, and Patent Document 2 describes a transfer property of a concavo-convex portion to a light guide plate by modifying a polycarbonate resin terminal. A method for improving the brightness by increasing the brightness, and Patent Document 3 propose a method for improving the brightness by introducing a copolyester carbonate having an aliphatic segment to improve the transferability.

However, although the method of Patent Document 1 improves the hue by adding an acrylic resin, it cannot be increased in light transmittance and brightness due to white turbidity, and the transmittance is improved by adding an alicyclic epoxy. Although there is a possibility, the effect of improving the hue is not recognized. In the case of Patent Document 2 and Patent Document 3, although an improvement effect of fluidity and transferability can be expected, there is a disadvantage that heat resistance is lowered.

On the other hand, it is known to blend polyethylene glycol or poly (2-methyl) ethylene glycol or the like into a thermoplastic resin such as a polycarbonate resin. Patent Document 4 discloses a γ-irradiation-resistant polycarbonate resin containing the same. Patent Document 5 describes a thermoplastic resin composition excellent in antistatic properties and surface appearance blended with PMMA or the like.
And in patent document 6, the proposal which improves the transmittance | permeability and a hue is made | formed by mix | blending the polyalkylene glycol comprised by a linear alkyl group. By adding polytetramethylene ether glycol, the transmittance and yellowing degree (yellow index: YI) are improved.

However, in recent years, especially in various portable terminals such as smartphones and tablet terminals, optical parts such as light guide plates are progressing at a remarkable speed of thinning and upsizing. In addition, high-speed injection is required. Along with this, there is a problem that gas generated at the time of molding increases and mold contamination easily proceeds. Therefore, the resin composition used for these moldings is required not only to have excellent optical properties but also to have little mold contamination during injection molding at high temperatures.

JP-A-11-158364 Japanese Patent Laid-Open No. 2001-208917 JP 2001-215336 A JP-A-1-22959 JP-A-9-227785 Japanese Patent No. 5699188

The present invention has been made in view of the above circumstances, and its purpose is to provide an optical material that has a good hue without impairing the original properties of the polycarbonate resin, and that has very little gas generation and mold contamination during molding. The object is to provide a polycarbonate resin composition for parts and an optical part.

As a result of intensive studies to achieve the above-mentioned problems, the inventor has a polystyrene-reduced weight average molecular weight (Mw) by a gel permeation chromatography in a specific range, and the weight average molecular weight (Mw) and number average. By blending a specific amount of polyalkylene glycol with a molecular weight (Mn) ratio (Mw / Mn) in a specific range to a phosphorus stabilizer and a polycarbonate resin, it has a good hue, and at the time of molding The present inventors have found that a polycarbonate resin composition for optical parts can be obtained with extremely little gas generation and mold contamination.
The present invention relates to the following polycarbonate resin composition for optical parts and optical parts.

[1] The polystyrene-reduced weight average molecular weight (Mw) measured with a tetrahydrofuran solvent by gel permeation chromatography with respect to 100 parts by mass of the polycarbonate resin (A) is more than 4,000 to 7,700, and the weight average molecular weight ( 0.1 to 4 parts by mass of polyalkylene glycol (B) having a ratio (Mw / Mn) of 2.5 or less (Mw) to number average molecular weight (Mn) and 0.005 of phosphorus stabilizer (C) A polycarbonate resin composition for optical parts, characterized by containing ~ 0.5 part by mass.
[2] The polycarbonate resin composition for optical components according to [1], wherein the polyalkylene glycol (B) has a tetramethylene ether unit.
[3] The polycarbonate resin composition for optical parts according to the above [1] or [2], wherein the polyalkylene glycol (B) is a polytetramethylene glycol homopolymer comprising tetramethylene ether units.
[4] The polyalkylene glycol (B) is a branch selected from a linear alkylene ether unit represented by the following general formula (3) and units represented by the following general formulas (4-1) to (4-4) The polycarbonate resin composition for optical components according to the above [1], which is a polyalkylene glycol copolymer having an alkylene ether unit.

(In formula (3), p represents an integer of 2 to 6.)

(In the formulas (4-1) to (4-4), R ¹ to R ¹⁰ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and each of the formulas (4-1) to (4- In 4), at least one of R ¹ to R ¹⁰ is an alkyl group having 1 to 3 carbon atoms.)

[5] The optical component according to [4], wherein the polyalkylene glycol (B) is a polyalkylene glycol copolymer having a tetramethylene ether unit and a unit represented by the general formula (4-1). Polycarbonate resin composition.
[6] The above [4], wherein the polyalkylene glycol (B) is a polyalkylene glycol copolymer having a tetramethylene ether unit and a unit represented by the general formula (4-2) or (4-3). 2. A polycarbonate resin composition for optical parts.
[7] The polycarbonate resin composition for optical parts according to the above [1], wherein the phosphorus stabilizer (C) is a phosphite compound represented by the following general formula (1) and / or (2).

[In Formula (1), R ¹ , R ² and R ³ may be the same or different and each represents an aryl group having 6 to 30 carbon atoms. ]

[In Formula (2), R ⁴ and R ⁵ may be the same or different and each represents an aryl group having 6 to 30 carbon atoms. ]
[8] The polycarbonate resin for optical components according to [1] or [2], further containing 0.0005 to 0.2 parts by mass of the epoxy compound (D) with respect to 100 parts by mass of the polycarbonate resin (A). Composition.
[9] The polycarbonate resin composition for optical components according to [8], wherein the epoxy compound (D) is an alicyclic epoxy compound.
[10] An optical component obtained by molding the polycarbonate resin composition according to any one of [1] to [9].

The polycarbonate resin composition of the present invention can provide an optical component having a good hue without deteriorating the original properties of the polycarbonate resin, generating little gas during molding, and extremely little mold contamination. .

It is a top view of the drop mold used for evaluation of mold contamination in an example.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples.
In the present specification, unless otherwise specified, “˜” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

The polycarbonate resin composition for optical parts of the present invention has a polystyrene-reduced weight average molecular weight (Mw) of more than 4,000 to 7,7, measured with a tetrahydrofuran solvent by gel permeation chromatography with respect to 100 parts by mass of the polycarbonate resin (A). 0.1 to 4 parts by mass of a polyalkylene glycol (B) having a ratio (Mw / Mn) of not more than 700 and a weight average molecular weight (Mw) to a number average molecular weight (Mn) of not more than 2.5, phosphorus system It contains 0.005 to 0.5 parts by mass of the stabilizer (C).
Hereinafter, each component, optical component and the like constituting the polycarbonate resin composition of the present invention will be described in detail.

[Polycarbonate resin (A)]
There is no restriction | limiting in the kind of polycarbonate resin used in this invention, A polycarbonate resin may use 1 type and may use 2 or more types together by arbitrary combinations and arbitrary ratios.

The polycarbonate resin is a polymer having a basic structure having a carbonic acid bond represented by the formula: — [— O—X—O—C (═O) —] —.
In the formula, X is generally a hydrocarbon, but for imparting various properties, X into which a hetero atom or a hetero bond is introduced may be used.

The polycarbonate resin can be classified into an aromatic polycarbonate resin in which the carbon directly bonded to the carbonic acid bond is an aromatic carbon, and an aliphatic polycarbonate resin in which the carbon is an aliphatic carbon, either of which can be used. Of these, aromatic polycarbonate resins are preferred from the viewpoints of heat resistance, mechanical properties, electrical characteristics, and the like.

Although there is no restriction | limiting in the specific kind of polycarbonate resin, For example, the polycarbonate polymer formed by making a dihydroxy compound and a carbonate precursor react is mentioned. At this time, in addition to the dihydroxy compound and the carbonate precursor, a polyhydroxy compound or the like may be reacted. Further, a method of reacting carbon dioxide with a cyclic ether using a carbonate precursor may be used. The polycarbonate polymer may be linear or branched. Further, the polycarbonate polymer may be a homopolymer composed of one type of repeating unit or a copolymer having two or more types of repeating units. At this time, the copolymer can be selected from various copolymerization forms such as a random copolymer and a block copolymer. In general, such a polycarbonate polymer is a thermoplastic resin.

Among monomers used as raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include:
Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (ie, resorcinol), 1,4-dihydroxybenzene;
Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 4,4′-dihydroxybiphenyl;

2,2′-dihydroxy-1,1′-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1, , 7-dihydroxynaphthalene, dihydroxynaphthalene such as 2,7-dihydroxynaphthalene;

2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis (3-hydroxyphenoxy) Dihydroxydiaryl ethers such as benzene and 1,3-bis (4-hydroxyphenoxy) benzene;

2,2-bis (4-hydroxyphenyl) propane (ie, bisphenol A),
1,1-bis (4-hydroxyphenyl) propane,
2,2-bis (3-methyl-4-hydroxyphenyl) propane,
2,2-bis (3-methoxy-4-hydroxyphenyl) propane,
2- (4-hydroxyphenyl) -2- (3-methoxy-4-hydroxyphenyl) propane,
1,1-bis (3-tert-butyl-4-hydroxyphenyl) propane,
2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane,
2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane,
2- (4-hydroxyphenyl) -2- (3-cyclohexyl-4-hydroxyphenyl) propane,
α, α'-bis (4-hydroxyphenyl) -1,4-diisopropylbenzene,
1,3-bis [2- (4-hydroxyphenyl) -2-propyl] benzene,
Bis (4-hydroxyphenyl) methane,
Bis (4-hydroxyphenyl) cyclohexylmethane,
Bis (4-hydroxyphenyl) phenylmethane,
Bis (4-hydroxyphenyl) (4-propenylphenyl) methane,
Bis (4-hydroxyphenyl) diphenylmethane,
Bis (4-hydroxyphenyl) naphthylmethane,
1,1-bis (4-hydroxyphenyl) ethane,
1,1-bis (4-hydroxyphenyl) -1-phenylethane,
1,1-bis (4-hydroxyphenyl) -1-naphthylethane,
1,1-bis (4-hydroxyphenyl) butane,
2,2-bis (4-hydroxyphenyl) butane,
2,2-bis (4-hydroxyphenyl) pentane,
1,1-bis (4-hydroxyphenyl) hexane,
2,2-bis (4-hydroxyphenyl) hexane,
1,1-bis (4-hydroxyphenyl) octane,
2,2-bis (4-hydroxyphenyl) octane,
4,4-bis (4-hydroxyphenyl) heptane,
2,2-bis (4-hydroxyphenyl) nonane,
1,1-bis (4-hydroxyphenyl) decane,
1,1-bis (4-hydroxyphenyl) dodecane,
Bis (hydroxyaryl) alkanes such as;

1,1-bis (4-hydroxyphenyl) cyclopentane,
1,1-bis (4-hydroxyphenyl) cyclohexane,
1,1-bis (4-hydroxyphenyl) -3,3-dimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3,4-dimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3,5-dimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane,
1,1-bis (4-hydroxy-3,5-dimethylphenyl) -3,3,5-trimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3-propyl-5-methylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3-tert-butyl-cyclohexane,
1,1-bis (4-hydroxyphenyl) -4-tert-butyl-cyclohexane,
1,1-bis (4-hydroxyphenyl) -3-phenylcyclohexane,
1,1-bis (4-hydroxyphenyl) -4-phenylcyclohexane,
Bis (hydroxyaryl) cycloalkanes such as;

9,9-bis (4-hydroxyphenyl) fluorene,
Cardio structure-containing bisphenols such as 9,9-bis (4-hydroxy-3-methylphenyl) fluorene;

4,4′-dihydroxydiphenyl sulfide,
Dihydroxydiaryl sulfides such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide;

Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;

4,4′-dihydroxydiphenyl sulfone,
Dihydroxydiaryl sulfones such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone;
Etc.

Among these, bis (hydroxyaryl) alkanes are preferable, and bis (4-hydroxyphenyl) alkanes are preferable, and 2,2-bis (4-hydroxyphenyl) propane (particularly from the viewpoint of impact resistance and heat resistance). That is, bisphenol A) is preferred.
In addition, 1 type may be used for an aromatic dihydroxy compound and it may use 2 or more types together by arbitrary combinations and a ratio.

In addition, when an example of a monomer that is a raw material of the aliphatic polycarbonate resin is given,
Ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3- Alkanediols such as diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, decane-1,10-diol;

Cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4- (2-hydroxyethyl) cyclohexanol, 2,2,4, Cycloalkanediols such as 4-tetramethyl-cyclobutane-1,3-diol;

Glycols such as ethylene glycol, 2,2'-oxydiethanol (ie, diethylene glycol), triethylene glycol, propylene glycol, spiro glycol and the like;

1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis ( 2-hydroxyethoxy) benzene, 2,3-bis (hydroxymethyl) naphthalene, 1,6-bis (hydroxyethoxy) naphthalene, 4,4′-biphenyldimethanol, 4,4′-biphenyldiethanol, 1,4- Aralkyldiols such as bis (2-hydroxyethoxy) biphenyl, bisphenol A bis (2-hydroxyethyl) ether, bisphenol S bis (2-hydroxyethyl) ether;

1,2-epoxyethane (ie ethylene oxide), 1,2-epoxypropane (ie propylene oxide), 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,4-epoxycyclohexane, 1-methyl -1,2-epoxycyclohexane, 2,3-epoxynorbornane, cyclic ethers such as 1,3-epoxypropane; and the like.

Among the monomers used as the raw material for the polycarbonate resin, carbonyl halides, carbonate esters and the like are used as examples of carbonate precursors. In addition, 1 type may be used for a carbonate precursor and it may use 2 or more types together by arbitrary combinations and a ratio.

Specific examples of the carbonyl halide include phosgene; haloformates such as a bischloroformate of a dihydroxy compound and a monochloroformate of a dihydroxy compound.

Specific examples of the carbonate ester include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonate bodies of dihydroxy compounds, monocarbonate bodies of dihydroxy compounds, and cyclic carbonates. And carbonate bodies of dihydroxy compounds such as

Manufacturing method of polycarbonate resin The manufacturing method of polycarbonate resin is not specifically limited, Arbitrary methods are employable. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, and a solid phase transesterification method of a prepolymer.
Hereinafter, a particularly preferable one of these methods will be described in detail.

Interfacial Polymerization Method First, a case where a polycarbonate resin is produced by an interfacial polymerization method will be described.
In the interfacial polymerization method, a dihydroxy compound and a carbonate precursor (preferably phosgene) are reacted in the presence of an organic solvent inert to the reaction and an aqueous alkaline solution, usually at a pH of 9 or higher. Polycarbonate resin is obtained by interfacial polymerization in the presence. In the reaction system, a molecular weight adjusting agent (terminal terminator) may be present as necessary, or an antioxidant may be present to prevent the oxidation of the dihydroxy compound.

The dihydroxy compound and the carbonate precursor are as described above. Of the carbonate precursors, phosgene is preferably used, and a method using phosgene is particularly called a phosgene method.

Examples of the organic solvent inert to the reaction include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene and dichlorobenzene; aromatic hydrocarbons such as benzene, toluene and xylene; It is done. In addition, 1 type may be used for an organic solvent and it may use 2 or more types together by arbitrary combinations and a ratio.

Examples of the alkali compound contained in the alkaline aqueous solution include alkali metal compounds and alkaline earth metal compounds such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and sodium hydrogen carbonate, among which sodium hydroxide and water Potassium oxide is preferred. In addition, 1 type may be used for an alkali compound and it may use 2 or more types together by arbitrary combinations and a ratio.

The concentration of the alkali compound in the alkaline aqueous solution is not limited, but it is usually used at 5 to 10% by mass in order to control the pH in the alkaline aqueous solution of the reaction to 10 to 12. For example, when phosgene is blown, the molar ratio of the bisphenol compound to the alkali compound is usually 1: 1.9 or more in order to control the pH of the aqueous phase to be 10 to 12, preferably 10 to 11. Among these, it is preferable that the ratio is 1: 2.0 or more, usually 1: 3.2 or less, and more preferably 1: 2.5 or less.

Examples of the polymerization catalyst include aliphatic tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine, and trihexylamine; alicyclic rings such as N, N′-dimethylcyclohexylamine and N, N′-diethylcyclohexylamine Tertiary amines; aromatic tertiary amines such as N, N′-dimethylaniline and N, N′-diethylaniline; quaternary ammonium salts such as trimethylbenzylammonium chloride, tetramethylammonium chloride, triethylbenzylammonium chloride, etc. Pyridine; guanine; guanidine salt; and the like. In addition, 1 type may be used for a polymerization catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

Examples of the molecular weight regulator include aromatic phenols having a monohydric phenolic hydroxyl group; aliphatic alcohols such as methanol and butanol; mercaptans; phthalimides and the like, among which aromatic phenols are preferred. Specific examples of such aromatic phenols include alkyl groups such as m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol, and p-long chain alkyl-substituted phenol. And substituted phenols; vinyl group-containing phenols such as isopropanyl phenol; epoxy group-containing phenols; carboxyl group-containing phenols such as o-hydroxybenzoic acid and 2-methyl-6-hydroxyphenylacetic acid; In addition, a molecular weight regulator may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

The amount used of the molecular weight regulator is usually 0.5 mol or more, preferably 1 mol or more, and usually 50 mol or less, preferably 30 mol or less, per 100 mol of the dihydroxy compound. By making the usage-amount of a molecular weight modifier into this range, the thermal stability and hydrolysis resistance of a resin composition can be improved.

In the reaction, the order of mixing the reaction substrate, reaction medium, catalyst, additive and the like is arbitrary as long as a desired polycarbonate resin is obtained, and an appropriate order may be arbitrarily set. For example, when phosgene is used as the carbonate precursor, the molecular weight regulator can be mixed at any time as long as it is between the reaction (phosgenation) of the dihydroxy compound and phosgene and the start of the polymerization reaction.
The reaction temperature is usually 0 to 40 ° C., and the reaction time is usually several minutes (for example, 10 minutes) to several hours (for example, 6 hours).

Next, a case where a polycarbonate resin is produced by a melt transesterification method will be described.
In the melt transesterification method, for example, a transesterification reaction between a carbonic acid diester and a dihydroxy compound is performed.

The dihydroxy compound is as described above.
On the other hand, examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate, and di-tert-butyl carbonate; diphenyl carbonate; substituted diphenyl carbonate such as ditolyl carbonate, and the like. Among these, diphenyl carbonate and substituted diphenyl carbonate are preferable, and diphenyl carbonate is more preferable. In addition, carbonic acid diester may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

The ratio of the dihydroxy compound and the carbonic acid diester is arbitrary as long as the desired polycarbonate resin is obtained, but it is preferable to use an equimolar amount or more of the carbonic acid diester with respect to 1 mol of the dihydroxy compound, and above all, 1.01 mol or more is used. It is more preferable. The upper limit is usually 1.30 mol or less. By setting it as such a range, the amount of terminal hydroxyl groups can be adjusted to a suitable range.

In polycarbonate resins, the amount of terminal hydroxyl groups tends to have a large effect on thermal stability, hydrolysis stability, color tone, and the like. For this reason, you may adjust the amount of terminal hydroxyl groups as needed by a well-known arbitrary method. In the transesterification reaction, a polycarbonate resin in which the amount of terminal hydroxyl groups is adjusted can be usually obtained by adjusting the mixing ratio of the carbonic diester and the aromatic dihydroxy compound; the degree of vacuum during the transesterification reaction, and the like. In addition, the molecular weight of the polycarbonate resin usually obtained can also be adjusted by this operation.

When adjusting the amount of terminal hydroxyl groups by adjusting the mixing ratio of the carbonic acid diester and the dihydroxy compound, the mixing ratio is as described above.
Further, as a more aggressive adjustment method, there may be mentioned a method in which a terminal terminator is mixed separately during the reaction. Examples of the terminal terminator at this time include monohydric phenols, monovalent carboxylic acids, carbonic acid diesters, and the like. In addition, 1 type may be used for a terminal terminator and it may use 2 or more types together by arbitrary combinations and a ratio.

When a polycarbonate resin is produced by the melt transesterification method, a transesterification catalyst is usually used. Any transesterification catalyst can be used. Among these, for example, it is preferable to use an alkali metal compound and / or an alkaline earth metal compound. In addition, auxiliary compounds such as basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds may be used in combination. In addition, 1 type may be used for a transesterification catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

In the melt transesterification method, the reaction temperature is usually 100 to 320 ° C. The pressure during the reaction is usually a reduced pressure condition of 2 mmHg or less. As a specific operation, a melt polycondensation reaction may be performed under the above conditions while removing by-products such as aromatic hydroxy compounds.

The melt polycondensation reaction can be performed by either a batch method or a continuous method. When performing by a batch type, the order which mixes a reaction substrate, a reaction medium, a catalyst, an additive, etc. is arbitrary as long as a desired aromatic polycarbonate resin is obtained, What is necessary is just to set an appropriate order arbitrarily. However, considering the stability of the polycarbonate resin and the like, the melt polycondensation reaction is preferably carried out continuously.

In the melt transesterification method, a catalyst deactivator may be used as necessary. As the catalyst deactivator, a compound that neutralizes the transesterification catalyst can be arbitrarily used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof. In addition, 1 type may be used for a catalyst deactivator and it may use 2 or more types together by arbitrary combinations and a ratio.

The amount of the catalyst deactivator used is usually 0.5 equivalents or more, preferably 1 equivalent or more, and usually 10 equivalents or less, relative to the alkali metal or alkaline earth metal contained in the transesterification catalyst. Preferably it is 5 equivalents or less. Furthermore, it is 1 ppm or more normally with respect to polycarbonate resin, and is 100 ppm or less normally, Preferably it is 20 ppm or less.

The molecular weight of the polycarbonate resin (A) is preferably 10,000 to 26,000 in terms of viscosity average molecular weight (Mv) converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. Preferably it is 10,500 or more, More preferably, it is 11,000 or more, Especially, 11,500 or more, Most preferably, it is 12,000 or more, More preferably, it is 24,000 or less, More preferably, it is 20,000 or less is there. By making the viscosity average molecular weight more than the lower limit of the above range, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, and by making the viscosity average molecular weight not more than the upper limit of the above range, The fluidity of the polycarbonate resin composition of the invention can be suppressed and improved, and the molding processability can be improved and the thin-wall molding process can be easily performed.
Two or more types of polycarbonate resins having different viscosity average molecular weights may be mixed and used, and in this case, a polycarbonate resin having a viscosity average molecular weight outside the above-mentioned preferred range may be mixed.

The viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and obtaining an intrinsic viscosity [η] (unit: dl / g) at a temperature of 20 ° C. using an Ubbelohde viscometer. , Η = 1.23 × 10 ⁻⁴ Mv ^0.83 . The intrinsic viscosity [η] is a value calculated from the following equation by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

The terminal hydroxyl group concentration of the polycarbonate resin is arbitrary and may be appropriately selected and determined, but is usually 1,000 ppm or less, preferably 800 ppm or less, more preferably 600 ppm or less. Thereby, the residence heat stability and color tone of polycarbonate resin can be improved more. In addition, the lower limit is usually 10 ppm or more, preferably 30 ppm or more, more preferably 40 ppm or more, particularly for polycarbonate resins produced by the melt transesterification method. Thereby, the fall of molecular weight can be suppressed and the mechanical characteristic of a resin composition can be improved more.

In addition, the unit of the terminal hydroxyl group concentration represents the mass of the terminal hydroxyl group with respect to the mass of the polycarbonate resin in ppm. The measuring method is a colorimetric determination by the titanium tetrachloride / acetic acid method (method described in Macromol. Chem. 88 215 (1965)).

The polycarbonate resin is a polycarbonate resin alone (the polycarbonate resin alone is not limited to an embodiment containing only one type of polycarbonate resin, and is used in a sense including an embodiment containing a plurality of types of polycarbonate resins having different monomer compositions and molecular weights, for example. .), Or an alloy (mixture) of a polycarbonate resin and another thermoplastic resin may be used in combination. Further, for example, for the purpose of further improving flame retardancy and impact resistance, a polycarbonate resin is copolymerized with an oligomer or polymer having a siloxane structure; for the purpose of further improving thermal oxidation stability and flame retardancy A monomer, oligomer or polymer having a copolymer; a copolymer with a monomer, oligomer or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermal oxidation stability; Copolymers with oligomers or polymers having an olefinic structure; copolymers with polyester resin oligomers or polymers for the purpose of improving chemical resistance; Good.

Further, in order to improve the appearance of the molded product and the fluidity, the polycarbonate resin may contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Furthermore, the polycarbonate ligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Further, the polycarbonate resin may be not only a virgin raw material but also a polycarbonate resin regenerated from a used product (so-called material-recycled polycarbonate resin).
However, the regenerated polycarbonate resin is preferably 80% by mass or less of the polycarbonate resin, and more preferably 50% by mass or less. Recycled polycarbonate resin is likely to have undergone deterioration such as heat deterioration and aging deterioration, so when such polycarbonate resin is used more than the above range, hue and mechanical properties can be reduced. It is because there is sex.

[Polyalkylene glycol (B)]
The polycarbonate resin composition for optical parts of the present invention has a polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography with a tetrahydrofuran solvent of more than 4,000 to 7,700, and the weight average molecular weight (Mw). And a polyalkylene glycol (B) having a ratio (Mw / Mn) of 2.5 or less to the number average molecular weight (Mn).
By containing such a polyalkylene glycol (B), it is possible to obtain an optical component having a good hue and generating very little gas during molding and mold contamination. When the weight average molecular weight (Mw) is 4,000 or less, the deposit on the mold at the time of injection molding increases. When the weight average molecular weight (Mw) exceeds 7,700, it becomes incompatible with polycarbonate and becomes cloudy, and Mw / Mn is 2.5. When it exceeds Mw, even if Mw exceeds 4,000, mold deposits at the time of injection molding increase.

The weight average molecular weight (Mw) of the polyalkylene glycol (B) is preferably 4,050 or more, more preferably 4,100 or more, further 4,200 or more, 4,300 or more, especially 4,400 or more, especially More than 4,500, most preferably more than 5,000, preferably 7,500 or less, more preferably 7,400 or less, further preferably 7,350 or less, particularly 7300 or less. The Mw / Mn of the polyalkylene glycol (B) is preferably 2.4 or less, more preferably 2.3 or less, still more preferably 2.2 or less, and particularly preferably 2.15 or less. The lower limit of Mw / Mn is usually 1.0, preferably 1.1, more preferably 1.2, still more preferably 1.3, and particularly 1.35 or more.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyalkylene glycol (B) are measured in terms of polystyrene measured with a tetrahydrofuran solvent by gel permeation chromatography. The details of the measurement method are as described in detail in the examples.

As the polyalkylene glycol (B), various polyalkylene glycols can be used. For example, a branched polyalkylene glycol represented by the following general formula (1) or a linear polyalkylene glycol represented by the following general formula (2) An alkylene glycol is mentioned as a preferable thing. The branched polyalkylene glycol represented by the following general formula (1) or the linear polyalkylene glycol represented by the following general formula (2) may be a copolymer with another copolymer component. Although it is good, it is preferably a homopolymer.

(Wherein R represents an alkyl group having 1 to 3 carbon atoms, and X and Y each independently represent a hydrogen atom, an aliphatic acyl group having 1 to 23 carbon atoms, an alkyl group having 1 to 23 carbon atoms, carbon An aryl group having 6 to 22 carbon atoms or an aralkyl group having 7 to 23 carbon atoms, and m represents an integer of 10 to 400.)
The branched polyalkylene glycol represented by the general formula (1) may be a homopolymer composed of one kind of R or a copolymer composed of different Rs.

(Wherein X and Y are each independently a hydrogen atom, an aliphatic acyl group having 2 to 23 carbon atoms, an alkyl group having 1 to 23 carbon atoms, an aryl group having 6 to 22 carbon atoms, or 7 to 23 carbon atoms). (Wherein p represents an integer of 2 to 6, and r represents an integer of 6 to 100).
The linear polyalkylene glycol represented by the general formula (2) may be a homopolymer composed of a single p or a copolymer composed of a different p.

As the branched polyalkylene glycol, in the general formula (1), (2-methyl) ethylene glycol in which X and Y are hydrogen atoms and R is a methyl group and (2-ethyl) ethylene glycol in which an ethyl group is preferable are preferable. .

As the linear polyalkylene glycol, in general formula (2), X and Y are hydrogen atoms, p is 2, polyethylene glycol, p is 3, polytrimethylene glycol, and p is 4, polytetramethylene. Preferable examples include glycol, polypentamethylene glycol having p of 5, and polyhexamethylene glycol having p of 6, more preferably polytrimethylene glycol and polytetramethylene glycol.

The polyalkylene glycol (B) is selected from linear alkylene ether units (P1) represented by the following general formula (3) and units represented by the following general formulas (4-1) to (4-4). A polyalkylene glycol copolymer having a branched alkylene ether unit (P2) is also preferred.

(In formula (3), p represents an integer of 2 to 6.)
As a linear alkylene ether unit represented by General formula (3), the single unit which consists of 1 type of p, or the several unit which consists of different p may mix.

The branched alkylene ether units represented by general formulas (4-1) to (4-4) are composed of branched alkylene ether units having any one structure of general formulas (4-1) to (4-4). It may be a homopolymer or a copolymer composed of branched alkylene ether units having a plurality of structures.

As the linear alkylene ether unit (P1) represented by the general formula (3), when describing it as glycol, ethylene glycol in which p is 2, trimethylene glycol in which p is 3, and tetra in which p is 4 Examples thereof include methylene glycol, pentamethylene glycol having p of 5, and hexamethylene glycol having p of 6, which may be mixed, preferably trimethylene glycol and tetramethylene glycol, and tetramethylene glycol is particularly preferable.

Trimethylene glycol is industrially obtained by hydroformylating ethylene oxide to obtain 3-hydroxypropionaldehyde and hydrogenating it, or 3-hydroxypropionaldehyde obtained by hydrating acrolein is hydrogenated with a Ni catalyst. Manufactured by the method. Recently, trimethylene glycol is also produced by reducing glycerin, glucose, starch and the like to microorganisms by a bio method.

When the branched alkylene ether unit represented by the general formula (4-1) is described as glycol, (2-methyl) ethylene glycol, (2-ethyl) ethylene glycol, (2,2-dimethyl) ethylene glycol, etc. These may be mixed, and (2-methyl) ethylene glycol and (2-ethyl) ethylene glycol are preferred.

When the branched alkylene ether unit represented by the general formula (4-2) is described as glycol, (2-methyl) trimethylene glycol, (3-methyl) trimethylene glycol, (2-ethyl) trimethylene glycol , (3-ethyl) triethylene glycol, (2,2-dimethyl) trimethylene glycol, (2,2-methylethyl) trimethylene glycol, (2,2-diethyl) trimethylene glycol (ie neopentyl glycol) (3,3-dimethyl) trimethylene glycol, (3,3-methylethyl) trimethylene glycol, (3,3-diethyl) trimethylene glycol, and the like, and these may be mixed.

The branched alkylene ether unit represented by the above general formula (4-3) is described as glycol. (3-Methyl) tetramethylene glycol, (4-methyl) tetramethylene glycol, (3-ethyl) tetramethylene glycol , (4-ethyl) tetramethylene glycol, (3,3-dimethyl) tetramethylene glycol, (3,3-methylethyl) tetramethylene glycol, (3,3-diethyl) tetramethylene glycol, (4,4-dimethyl) ) Tetramethylene glycol, (4,4-methylethyl) tetramethylene glycol, (4,4-diethyl) tetramethylene glycol, etc., and these may be mixed, and (3-methyl) tetramethylene glycol preferable.

When the branched alkylene ether unit represented by the general formula (4-4) is described as glycol, (3-methyl) pentamethylene glycol, (4-methyl) pentamethylene glycol, (5-methyl) pentamethylene glycol , (3-ethyl) pentamethylene glycol, (4-ethyl) pentamethylene glycol, (5-ethyl) pentamethylene glycol, (3,3-dimethyl) pentamethylene glycol, (3,3-methylethyl) pentamethylene glycol (3,3-diethyl) pentamethylene glycol, (4,4-dimethyl) pentamethylene glycol, (4,4-methylethyl) pentamethylene glycol, (4,4-diethyl) pentamethylene glycol, (5,5 -Dimethyl) pentamethyleneglycol , (5,5-methylethyl) pentamethylene glycol, (5,5-diethyl) such as pentamethylene glycol, and the like, may also be these mixtures.

The units represented by the general formulas (4-1) to (4-4) constituting the branched alkylene ether unit have been described for convenience by way of glycols, but are not limited to these glycols. Alternatively, these polyether-forming derivatives may be used.

Preferable examples of the polyalkylene glycol copolymer include a copolymer composed of a tetramethylene ether unit and a unit represented by the general formula (4-3), particularly a tetramethylene ether unit and 3-methyltetramethylene. A copolymer comprising an ether unit is more preferable. Further, a copolymer comprising a tetramethylene ether unit and a unit represented by the general formula (4-1) is also preferred, and in particular, a copolymer comprising a tetramethylene ether unit and a 2-methylethylene ether unit, and tetramethylene ether More preferred are copolymers comprising units and 2-ethylethylene ether units. Further, a copolymer composed of a tetramethylene ether unit and the above general formula (4-2) is also preferable, and a copolymer composed of a 2,2-dimethyltrimethylene ether unit, that is, a neopentyl glycol ether unit is also preferable.

The polyalkylene glycol copolymer may be a random copolymer or a block copolymer.

The linear alkylene ether unit (P1) represented by the general formula (3) and the branched alkylene ether unit (P2) represented by the general formulas (4-1) to (4-4) of the polyalkylene glycol copolymer. The copolymerization ratio of (P1) / (P2) is preferably 95/5 to 5/95, more preferably 93/7 to 40/60, and still more preferably 90/10. It is more preferable that the linear alkylene ether unit (P1) is rich.
The mole fraction is measured using a ¹ H-NMR measuring apparatus and deuterated chloroform as a solvent.

Further, as polyalkylene glycol (B), even if one or both ends thereof are blocked with fatty acid or alcohol, there is no effect on the performance expression, and fatty acid esterified products or etherified products can be used similarly. In the general formulas (1) and (2), X and / or Y may be an aliphatic acyl group or alkyl group having 1 to 23 carbon atoms.

The esterified product or etherified product of polyalkylene glycol does not necessarily need to be esterified or etherified entirely, and is preferably a partially esterified product or an etherified product.

As the fatty acid ester product, either a linear or branched fatty acid ester can be used, and the fatty acid constituting the fatty acid ester may be a saturated fatty acid or an unsaturated fatty acid. Also, those in which some hydrogen atoms are substituted with a substituent such as a hydroxyl group can be used.
The fatty acid constituting the fatty acid ester is a monovalent or divalent fatty acid having 1 to 23 carbon atoms, such as a monovalent saturated fatty acid, specifically formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid. , Enanthic acid, caprylic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid and monovalent unsaturated fatty acids, specifically, Unsaturated fatty acids such as oleic acid, elaidic acid, linoleic acid, linolenic acid and arachidonic acid, and divalent fatty acids having 10 or more carbon atoms, specifically sebacic acid, undecanedioic acid, dodecanedioic acid, tetradecanedioic acid , Tapsia and decenedioic acid, undecenedioic acid, dodecenedioic acid.
These fatty acids can be used alone or in combination. The fatty acid also includes a fatty acid having one or more hydroxyl groups in the molecule.

Preferable specific examples of the fatty acid ester of polyalkylene glycol include polypropylene glycol stearate in which R is a methyl group, X and Y are aliphatic acyl groups having 18 carbon atoms in general formula (I-1), and R is a methyl group , Polypropylene glycol behenate wherein X and Y are aliphatic acyl groups having 22 carbon atoms. Preferable specific examples of the fatty acid ester of polyalkylene glycol include polyalkylene glycol monopalmitate, polyalkylene glycol dipalmitate, polyalkylene glycol monostearate, polyalkylene glycol distearate, polyalkylene glycol (monopalmitin) Acid / monostearic acid) ester, polyalkylene glycol behenate and the like.

The alkyl group constituting the alkyl ether of the polyalkylene glycol may be either linear or branched, for example, carbon number such as methyl group, ethyl group, propyl group, butyl group, octyl group, lauryl group, stearyl group, etc. Examples of such polyalkylene glycols include alkylmethyl ether, ethyl ether, butyl ether, lauryl ether, stearyl ether and the like of polyalkylene glycol.

The polyalkylene glycol (B) may contain a polyol-derived structure such as 1,4-butanediol, glycerol, sorbitol, benzenediol, bisphenol A, cyclohexanediol, and spiroglycol in the structure. By adding these polyols during the polymerization of the polyalkylene glycol, these organic groups can be imparted to the main chain. Particularly preferred are glycerol, sorbitol, bisphenol A and the like.

Examples of the polyalkylene glycol having an organic group in the structure include polyethylene glycol glyceryl ether, poly (2-methyl) ethylene glycol glyceryl ether, poly (2-ethyl) ethylene glycol glyceryl ether, polytetramethylene glycol glyceryl ether, Polyethylene glycol-poly (2-methyl) ethylene glycol glyceryl ether, polytetramethylene glycol-poly (2-methyl) ethylene glycol glyceryl ether, polytetramethylene glycol-poly (2-ethyl) polyethylene glycol glyceryl ether, polyethylene glycol sorbitol Ether, poly (2-methyl) ethylene glycol sorbyl ether, poly (2-ethyl) ethylene glycol sorbyl Ether, polytetramethylene glycol sorbitol ether, polyethylene glycol-poly (2-methyl) ethylene glycol sorbitol ether, polytetramethylene glycol-poly (2-methyl) ethylene glycol sorbitol ether, polytetramethylene glycol-poly (2 -Ethyl) ethylene glycol sorbyl ether, bisphenol A-bis (polyethylene glycol) ether, bisphenol A-bis (poly (2-methyl) ethylene glycol) ether, bisphenol A-bis (poly (2-ethyl) ethylene glycol) ether Bisphenol A-bis (polytetramethylene glycol) ether, bisphenol A-bis (polyethylene glycol-poly (2-methyl) ethylene glycol) Preferred examples include ether, bisphenol A-bis (polytetramethylene glycol-poly (2-methyl) ethylene glycol) ether, and bisphenol A-bis (polytetramethylene glycol-poly (2-ethyl) polyethylene glycol) ether. .

The above polyalkylene glycol (B) may be used alone or in combination of two or more.

The content of the polyalkylene glycol (B) is 0.1 to 4 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). The preferred content is 0.15 parts by mass or more, more preferably 0.2 parts by mass or more, further preferably 0.3 parts by mass or more, particularly preferably 0.4 parts by mass or more, preferably 3.5 parts by mass. Hereinafter, it is more preferably 3 parts by mass or less, further preferably 2.5 parts by mass or less, and particularly preferably 2 parts by mass or less. When the content is less than 0.1 parts by mass, the hue and yellowing are not sufficiently improved. When the content exceeds 4 parts by mass, the transmittance decreases due to white turbidity of the polycarbonate resin, and at the time of melt kneading by an extruder. The strand breaks frequently, making it difficult to produce resin composition pellets.

[Phosphorus stabilizer (C)]
The polycarbonate resin composition of the present invention contains a phosphorus stabilizer. By containing a phosphorus stabilizer, the hue of the polycarbonate resin composition of the present invention is improved, and the heat discoloration is further improved.
Any known phosphorous stabilizer can be used. Specific examples include phosphorus oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphoric acid Phosphates of Group 1 or Group 2B metals such as potassium, sodium phosphate, cesium phosphate, and zinc phosphate; phosphate compounds, phosphite compounds, phosphonite compounds and the like can be mentioned, and phosphite compounds are particularly preferred. By selecting a phosphite compound, a polycarbonate resin composition having higher discoloration resistance and continuous productivity can be obtained.

Here, the phosphite compound is a trivalent phosphorus compound represented by the general formula: P (OR) ₃ , and R represents a monovalent or divalent organic group.
Examples of such phosphite compounds include triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphine. Phyto, monooctyl diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, Bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite, bis (2,6-di-tert-butylphenyl) octyl phosphite, 2,2-methylene (4,6-di-tert-butylphenyl) octyl phosphite, tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylene-diphosphite, 6- [3- (3-tert- Butyl-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3,2] -dioxaphosphine.

Among such phosphite compounds, an aromatic phosphite compound represented by the following formula (1) or (2) is more preferable because the heat discoloration of the polycarbonate resin composition of the present invention is effectively enhanced. .

[In Formula (2), R ⁴ and R ⁵ may be the same or different and each represents an aryl group having 6 to 30 carbon atoms. ]

As the phosphite compound represented by the above formula (1), triphenyl phosphite, tris (monononylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite and the like are preferable. Tris (2,4-di-tert-butylphenyl) phosphite is more preferred. Specific examples of such organic phosphite compounds include, for example, “ADEKA STAB 1178” manufactured by ADEKA, “SUMILIZER TNP” manufactured by Sumitomo Chemical Co., Ltd., “JP-351” manufactured by Johoku Chemical Industry Co., Ltd., and “ADEKA STAB manufactured by ADEKA. 2112 "," Irgaphos 168 "manufactured by BASF," JP-650 "manufactured by Johoku Chemical Industry Co., Ltd., and the like.

Examples of the phosphite compound represented by the above formula (2) include bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,6-di-tert-butyl). Those having a pentaerythritol diphosphite structure such as -4-methylphenyl) pentaerythritol diphosphite and bis (2,4-dicumylphenyl) pentaerythritol diphosphite are particularly preferred. Specific examples of such an organic phosphite compound include “Adekastab PEP-24G”, “Adekastab PEP-36” manufactured by Adeka, “Doverphos S-9228” manufactured by Doverchemical, and the like.

Among the phosphite compounds, the aromatic phosphite compound represented by the above formula (2) is more preferable because the hue is more excellent.
In addition, 1 type may contain phosphorus stabilizer and 2 or more types may contain it by arbitrary combinations and a ratio.

The content of the phosphorus stabilizer (C) is 0.005 to 0.5 parts by mass, preferably 0.007 parts by mass or more, more preferably 0.005 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). 008 parts by mass or more, particularly preferably 0.01 parts by mass or more, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, still more preferably 0.2 parts by mass or less, particularly 0 .1 part by mass or less. When the content of the phosphorus stabilizer (C) is less than 0.005 parts by mass of the above range, the hue and heat discoloration are insufficient, and the content of the phosphorus stabilizer (C) is 0.5 parts by mass. If it exceeds 1, not only the heat discoloration is deteriorated, but also the wet heat stability is lowered.

[Epoxy compound (D)]
It is also preferable that the resin composition of the present invention contains an epoxy compound (D). By containing the epoxy compound (D) together with the polyalkylene glycol (B), the heat discoloration can be further improved.

As the epoxy compound (D), a compound having one or more epoxy groups in one molecule is used. Specifically, phenyl glycidyl ether, allyl glycidyl ether, t-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl -3 ', 4'-epoxy-6'-methylcyclohexyl carboxylate, 2,3-epoxycyclohexylmethyl-3', 4'-epoxycyclohexyl carboxylate, 4- (3,4-epoxy-5-methylcyclohexyl) Butyl-3 ′, 4′-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6 ′ -Methylsiloxyl carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxy dicyclopentadienyl ether, bis- Epoxyethylene glycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxytalate, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1,2, -Epoxycyclohexane, 3-methyl-5-t-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxy N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate, N-butyl-2-isopropyl-3,4-epoxy -5-methylcyclohexyl carboxylate, octadecyl-3,4-epoxycyclohexyl carboxylate, 2-ethylhexyl-3 ', 4'-epoxycyclohexyl carboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3', 4'-epoxycyclohexylcarboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3-tert-butyl-4,5-epoxytetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyldicarboxylate Rate, j-n-b Le -3-t-butyl-4,5-epoxy - cis-1,2-cyclohexyl dicarboxylate, epoxidized soybean oil, can be preferably exemplified such as epoxidized linseed oil.
Epoxy compounds may be used alone or in combination of two or more.

Of these, alicyclic epoxy compounds are preferably used, and 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate is particularly preferable.

The content of the epoxy compound (D) is preferably 0.0005 to 0.2 parts by mass, more preferably 0.001 parts by mass or more, and still more preferably 0.005 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). 003 parts by mass or more, particularly preferably 0.005 parts by mass or more, more preferably 0.15 parts by mass or less, still more preferably 0.1 parts by mass or less, and particularly preferably 0.05 parts by mass or less. When the content of the epoxy compound (D) is less than 0.0005 parts by mass, the hue and the heat discoloration tend to be insufficient. When the content exceeds 0.2 parts by mass, the heat discoloration tends to deteriorate, Hue and wet heat stability tend to decrease.

The mass ratio (C / D) of the content of the epoxy compound (D) and the content of the phosphorus stabilizer (C) is preferably 0, or more than 0 and less than 6.0, more preferably It is 0.1 to 5.5, and more preferably 0.5 to 5.0.

[Additives, etc.]
The polycarbonate resin composition of the present invention includes other additives other than those described above, for example, antioxidants, mold release agents, ultraviolet absorbers, fluorescent brighteners, pigments, dyes, other polymers other than polycarbonate resins, Additives such as a flame retardant, an impact resistance improver, an antistatic agent, a plasticizer, and a compatibilizing agent can be contained. These additives may be used alone or in combination of two or more.

[Production Method of Polycarbonate Resin Composition]
There is no restriction | limiting in the manufacturing method of the polycarbonate resin composition of this invention, The manufacturing method of a well-known polycarbonate resin composition can be employ | adopted widely, polycarbonate resin (A), polyalkylene glycol (B), and phosphorus stabilizer (C), In addition, other components to be blended as necessary are mixed in advance using various mixers such as a tumbler and a Henschel mixer, and then Banbury mixer, roll, Brabender, single-screw kneading extruder, twin-screw kneading extruder And a melt kneading method using a mixer such as a kneader. The temperature for melt kneading is not particularly limited, but is usually in the range of 240 to 320 ° C.

[Optical parts]
The polycarbonate resin composition for optical components of the present invention can be produced by molding pellets obtained by pelletizing the above-described polycarbonate resin composition by various molding methods. Moreover, the resin melt-kneaded by an extruder can be directly molded into an optical component without going through the pellets.

The polycarbonate resin composition of the present invention is excellent in fluidity and hue, and has very little gas generation and mold contamination during molding. Therefore, by injection molding, optical components, particularly thin optical components that are prone to mold contamination. It is particularly preferably used for molding. The resin temperature at the time of injection molding is preferably molded at a resin temperature higher than 260 to 300 ° C., which is a temperature generally applied to injection molding of polycarbonate resin, particularly in the case of a thin molded product. A resin temperature of ˜400 ° C. is preferred. The resin temperature is more preferably 310 ° C or higher, further preferably 315 ° C or higher, particularly preferably 320 ° C or higher, and more preferably 390 ° C or lower. When the conventional polycarbonate resin composition is used, there is a problem that when the resin temperature at the time of molding is increased in order to mold a thin molded product, the molded product is likely to be yellowed. By using the composition, it becomes possible to produce a molded product having a good hue, particularly a thin-walled optical component, even in the above temperature range.
The resin temperature is grasped as the barrel set temperature when it is difficult to directly measure the resin temperature.

Here, the thin-walled molded article refers to a molded article having a plate-shaped portion having a thickness of usually 1 mm or less, preferably 0.8 mm or less, more preferably 0.6 mm or less. Here, the plate-like portion may be a flat plate or a curved plate, may be a flat surface, may have irregularities on the surface, and the cross section has an inclined surface. Or a wedge-shaped cross section.

Examples of optical components include components of equipment and instruments that directly or indirectly use light sources such as LEDs, organic EL, incandescent bulbs, fluorescent lamps, and cathode tubes, and light guide plates and surface light emitter members are typical. It is illustrated as a thing.
The light guide plate is used to guide light from a light source such as an LED in a liquid crystal backlight unit, various display devices, and lighting devices. It diffuses by the unevenness and emits uniform light. The shape is usually flat, and the surface may or may not have irregularities.
The light guide plate is usually formed preferably by an injection molding method, an ultra-high speed injection molding method, an injection compression molding method, a melt extrusion molding method (for example, a T-die molding method), or the like.
The light guide plate molded using the resin composition of the present invention does not have white turbidity or transmittance, has a good hue, and has few molding defects due to mold contamination.

The light guide plate using the polycarbonate resin composition of the present invention can be suitably used in the fields of liquid crystal backlight units, various display devices, and lighting devices. Examples of such devices include mobile phones, mobile notebooks, netbooks, slate PCs, tablet PCs, smartphones, tablet terminals, and other portable terminals, cameras, watches, notebook computers, various displays, lighting devices, and the like. It is done.

Further, the shape as the optical component may be a film or a sheet, and specific examples thereof include a light guide film and the like.

In addition, as an optical component, a light guide or a lens that guides light from a light source such as an LED in a vehicle headlight (head lamp) or a rear lamp or a fog lamp for an automobile or a motorcycle is also suitable. Also, it can be suitably used.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not construed as being limited to the following examples.

The raw materials and evaluation methods used in the following examples and comparative examples are as follows. In addition, the measuring method of the viscosity average molecular weight of polycarbonate resin (A) is as having mentioned above.

Specifically, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyalkylene glycol were measured by gel permeation chromatography as follows.
As the gel permeation chromatography apparatus, HLC-8320 (manufactured by Tosoh Corporation) was used, and KF-G, KF-805L × 3, and KF-800D (all manufactured by Shodex) were connected and used as columns. The column temperature was 40 ° C. The detector used was an RI detector of HLC-8320. Tetrahydrofuran was used as an eluent, and a calibration curve was prepared using standard polystyrene manufactured by Shodex.

(Examples 1 to 14, Comparative Examples 1 to 5)
[Production of resin composition pellets]
Each component described above was blended in the proportions (parts by mass) shown in Tables 2 to 3 below, mixed for 20 minutes with a tumbler, and then a single screw extruder with a screw diameter of 40 mm (manufactured by Tanabe Plastic Machinery Co., Ltd.) VS-40 "), the cylinder temperature was melt kneaded at 240 ° C, and pellets were obtained by strand cutting.

[Measurement of Hue (YI)]
The obtained pellets were dried at 120 ° C. for 5 to 7 hours with a hot air circulating dryer, and then with an injection molding machine (“EC100SX-2A” manufactured by Toshiba Machine Co., Ltd.) at a resin temperature of 340 ° C. and a mold temperature of 80 ° C. A long optical path molded product (300 mm × 7 mm × 4 mm) was molded.
About this long optical path molded product, YI (yellowing degree) was measured at an optical path length of 300 mm. For the measurement, a long optical path spectral transmission color meter (“ASA 1” manufactured by Nippon Denshoku Industries Co., Ltd., C light source, 2 ° visual field) was used.

[Evaluation of mold contamination (mold deposits)]
Contamination evaluation in injection molding (mold dirt)
After the pellets obtained above were dried at 120 ° C. for 5 hours, an injection molding machine (“SE8M” manufactured by Sumitomo Heavy Industries, Ltd.) was used and a drop mold as shown in FIG. A comparative example shows the state of contamination due to white deposits generated on the metal mirror surface on the mold fixing side after 200 shot injection molding under conditions of a temperature of 340 ° C., a molding cycle of 10 seconds, and a mold temperature of 40 ° C. The following criteria compared with 1 were evaluated and judged visually.
A: The amount of mold deposits is much less than that after the 200-shot molding in Comparative Example 1, and the mold contamination resistance is very good.
B: Although mold deposits are less than the state after the 200-shot molding of Comparative Example 1, some mold resistance is observed.
C: Mold adhering material is at the same level as the state after 200 shot molding of Comparative Example 1.
D: There are more mold deposits than the state after the 200-shot molding of Comparative Example 1, and the mold contamination is noticeable.

The drop mold shown in FIG. 1 is a mold designed to introduce a resin composition from the gate G so that the generated gas easily accumulates at the tip P portion. The gate G has a width of 1 mm and a thickness of 1 mm. In FIG. 1, the width h1 is 14.5 mm, the length h2 is 7 mm, the length h3 is 27 mm, and the thickness of the molded part is 3 mm.
The above evaluation results are shown in Table 2 below.

The polycarbonate resin composition of the present invention has a good hue and generates very little gas during molding and mold contamination, and can therefore be used very suitably for optical parts.

Claims

The polystyrene-reduced weight average molecular weight (Mw) measured with a tetrahydrofuran solvent by gel permeation chromatography with respect to 100 parts by mass of the polycarbonate resin (A) is 4,000 to 7,700, and the weight average molecular weight (Mw) The polyalkylene glycol (B) having a ratio (Mw / Mn) to the number average molecular weight (Mn) of 2.5 or less is 0.1 to 4 parts by mass, and the phosphorus stabilizer (C) is 0.005 to 0.005. A polycarbonate resin composition for optical parts, comprising 5 parts by mass.
The polycarbonate resin composition for optical components according to claim 1, wherein the polyalkylene glycol (B) has a tetramethylene ether unit.
The polycarbonate resin composition for optical parts according to claim 1 or 2, wherein the polyalkylene glycol (B) is a polytetramethylene glycol homopolymer comprising tetramethylene ether units.
The polyalkylene glycol (B) is a branched alkylene ether unit selected from linear alkylene ether units represented by the following general formula (3) and units represented by the following general formulas (4-1) to (4-4) The polycarbonate resin composition for optical components according to claim 1, wherein the polycarbonate resin composition is a polyalkylene glycol copolymer.

(In formula (3), p represents an integer of 2 to 6.)

(In the formulas (4-1) to (4-4), R 1 to R 10 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and each of the formulas (4-1) to (4- In 4), at least one of R 1 to R 10 is an alkyl group having 1 to 3 carbon atoms.)
The polycarbonate resin composition for optical parts according to claim 4, wherein the polyalkylene glycol (B) is a polyalkylene glycol copolymer having a tetramethylene ether unit and a unit represented by the general formula (4-1). .
The optical system according to claim 4, wherein the polyalkylene glycol (B) is a polyalkylene glycol copolymer having a tetramethylene ether unit and a unit represented by the general formula (4-2) or (4-3). Polycarbonate resin composition for parts.
The polycarbonate resin composition for optical components according to claim 1, wherein the phosphorus stabilizer (C) is a phosphite compound represented by the following general formula (1) and / or (2).

[In Formula (1), R 1 , R 2 and R 3 may be the same or different and each represents an aryl group having 6 to 30 carbon atoms. ]

[In Formula (2), R 4 and R 5 may be the same or different and each represents an aryl group having 6 to 30 carbon atoms. ]
The polycarbonate resin composition for optical parts according to claim 1 or 2, further comprising 0.0005 to 0.2 parts by mass of the epoxy compound (D) with respect to 100 parts by mass of the polycarbonate resin (A).
The polycarbonate resin composition for optical components according to claim 8, wherein the epoxy compound (D) is an alicyclic epoxy compound.
An optical component formed by molding the polycarbonate resin composition according to any one of claims 1 to 9.