JP6526871B2 - Polycarbonate resin composition for thin optical parts and thin optical parts - Google Patents

Description

  The present invention relates to a polycarbonate resin composition for thin-walled optical components and a thin-walled optical component, and more specifically, a polycarbonate resin composition for thin-walled optical components having high transmittance and good hue and excellent heat-resistant discoloration Thin-walled optical components.

  A planar light source device is incorporated in a liquid crystal display device used for a personal computer, a cellular phone or the like in order to meet the demand for thinning, weight saving, labor saving and high definition. The planar light source device has a wedge-shaped light guide plate or a flat plate shape having a uniform inclined surface for the purpose of guiding the incoming light uniformly and efficiently to the liquid crystal display side. A light guide plate is provided. There is also a type in which a concavo-convex 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-mentioned concavo-convex pattern is imparted by transfer of 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 polymethyl methacrylate (PMMA), but recently, a display device for projecting a clearer image is required, and the heat generated in the vicinity of the light source raises the temperature inside the device It is being replaced by polycarbonate resin materials with higher heat resistance.

  A 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 a surface light source is made of a light guide plate made of polycarbonate resin and a light source. When configured, there is a problem that the brightness is low. In recent years, it has been required to reduce the difference in chromaticity between the light entrance portion of the light guide plate and a location away from the light entrance portion, but polycarbonate resins have a problem of being easily yellowed as compared with PMMA resins.

  Patent Document 1 discloses a method of improving light transmittance and brightness by adding an acrylic resin and an alicyclic epoxy, and Patent Document 2 modifies the terminal end of a polycarbonate resin and transfers the concavo-convex portion to a light guide plate. Patent Document 3 proposes a method for improving luminance by introducing a copolyester carbonate having an aliphatic segment to improve the above-mentioned transferability.

  However, according to the method of Patent Document 1, although the hue is improved by the addition of the acrylic resin, the light transmittance and the luminance can not be increased because they become cloudy, and the transmittance is improved by the addition of the alicyclic epoxy. Although there is a possibility of improvement, the improvement effect of the hue is not recognized. In the case of Patent Document 2 and Patent Document 3, although the effect of improving the fluidity and the transferability can be expected, there is a drawback that the heat resistance is lowered.

On the other hand, it is known to blend polyethylene glycol or poly (2-methyl) ethylene glycol etc. into a thermoplastic resin such as a polycarbonate resin, and Patent Document 4 contains a γ-ray-resistant polycarbonate resin containing it. Patent Document 5 describes a thermoplastic resin composition excellent in antistatic property and surface appearance blended in PMMA or the like.
Then, Patent Document 6, _{wherein: X-О- [CH (-R} ) -CH 2 -O] n-Y (R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X and Y are hydrogen atoms or It has been proposed to improve the transmittance and the color by blending polyethylene glycol or poly (2-alkyl) ethylene glycol represented by the aliphatic acyl group having 2 to 23 carbon atoms. By blending polyethylene glycol or poly (2-alkyl) ethylene glycol, the transmittance and yellowing index (Yellow Index: YI) show some improvement.

  However, in recent various types of mobile terminals such as smartphones and tablet terminals, thinning, large-sized thinning, and high performance are progressing at a remarkable speed, and as a result, in the light guide plate and the like, There is a need for materials for thin-walled optical components that are superior in color tone and heat discoloration resistance at higher levels.

JP-A-11-158364 JP 2001-208917 A JP 2001-215336 A Unexamined-Japanese-Patent No. 1-22959 Unexamined-Japanese-Patent No. 9-227785 Patent No. 4069364

  The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a polycarbonate resin composition for thin optical parts having good transmittance and hue and good heat discoloration resistance without impairing the original characteristics of the polycarbonate resin. To provide goods.

As a result of intensive studies to achieve the above-mentioned problems, the inventor of the present invention has found that a polycarbonate resin is a polyalkylene glycol compound having a number average molecular weight of 500 to 5,000 with at least one end sealed with an aryl group or an aralkyl group. It has been surprisingly found that by blending in a specific amount, it is possible to achieve very good heat discoloration resistance in addition to more excellent transmittance and hue, and to complete the present invention.
The present invention provides the following polycarbonate resin composition for thin optical parts, thin optical parts, and a method of manufacturing thin optical parts.

[1] 0.2 to 4 mass of a polyalkylene glycol compound (B) having a number average molecular weight of 500 to 5,000 having at least one end sealed with an aryl group or an aralkyl group relative to 100 parts by mass of the polycarbonate resin (A) Polycarbonate resin composition for thin-walled optical parts, characterized in that it contains 0.0005 to 0.2 parts by mass of part and an epoxy compound (C) .
[2] The polycarbonate resin composition for thin-walled optical parts according to the above [1], wherein the polyalkylene glycol compound (B) has only one end sealed with an aryl group or an aralkyl group.
[3] The polycarbonate resin composition for thin optical parts according to the above [1] or [2], wherein the viscosity average molecular weight (Mv) of the polycarbonate resin (A) is 10,000 to 15,000 .
[4 ] The polycarbonate resin composition for thin-walled optical parts according to any one of the above [1] to [ 3 ], which has a spectral transmittance of 30% or more at a wavelength of 400 nm measured with an optical path length of 300 mm.
[ 5 ] A thin-walled optical component obtained by molding the polycarbonate resin composition according to any one of the above [1] to [ 4 ].
[ 6 ] The thin-walled optical component according to the above [ 5 ], which is a light guide plate having a thickness of 1 mm or less.
[ 7 ] A method for producing a thin-walled optical component having a thickness of 1 mm or less, which comprises injection molding the polycarbonate resin composition according to any one of the above [1] to [ 4 ] at 305 to 380 ° C.

  According to the present invention, a polycarbonate resin composition for thin-walled optical parts having good transmittance and hue and good heat-resistant discoloration is provided without any deterioration in the intrinsic properties of the polycarbonate resin, and the transmittance and hue are good. Thin-walled optical components can be provided.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples.
In addition, in this specification, unless there is particular notice, "-" is used by the meaning included as a lower limit and an upper limit with the numerical value described before and behind that.

[Overview]
The polycarbonate resin composition for thin-walled optical components of the present invention is a polyalkylene glycol compound having a number average molecular weight of 500 to 5,000, in which at least one end is sealed with an aryl group or an aralkyl group per 100 parts by mass of the polycarbonate resin (A). It is characterized in that 0.2 to 4 parts by mass of (B) and 0.0005 to 0.2 parts by mass of the epoxy compound (C) are contained.
Hereinafter, each component constituting the polycarbonate resin composition of the present invention, a thin optical component, a method of manufacturing the thin optical component, and the like will be described in detail.

[Polycarbonate resin (A)]
There is no restriction on the type of polycarbonate resin used in the present invention, and one type of polycarbonate resin may be used, or two or more types may be used in combination in an arbitrary ratio and an arbitrary ratio.

The polycarbonate resin is a polymer of 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 a hetero atom or X having a hetero bond may be used for various properties.

  Further, polycarbonate resins can be classified into aromatic polycarbonate resins in which carbon directly bonded to carbonic bonds is aromatic carbon and aliphatic polycarbonate resins in which aliphatic carbon is directly bonded, but any of them can be used. Among them, aromatic polycarbonate resins are preferable from the viewpoint of heat resistance, mechanical physical properties, electrical characteristics and the like.

  Although there is no restriction | limiting in the specific kind of polycarbonate resin, For example, the polycarbonate polymer which makes 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. Alternatively, carbon dioxide may be reacted with cyclic ether as a carbonate precursor. The polycarbonate polymer may be linear or branched. Furthermore, the polycarbonate polymer may be a homopolymer comprising one kind of repeating unit, or may be a copolymer having two or more kinds of repeating units. At this time, as the copolymer, various copolymer forms such as a random copolymer and a block copolymer can be selected. In general, such polycarbonate polymers are thermoplastic resins.

  Among the monomers used as the raw material of the aromatic polycarbonate resin, to cite an example of the aromatic dihydroxy compound,

Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (that is, 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 , Dihydroxynaphthalenes such as 7-dihydroxynaphthalene, 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) Dihydroxy diaryl ethers such as benzene and 1,3-bis (4-hydroxyphenoxy) benzene;

2,2-bis (4-hydroxyphenyl) propane (that is, 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-naphthyl ethane,
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,
1,1-bis (4-hydroxyphenyl) hexane,
2,2-bis (4-hydroxyphenyl) hexane,
4,4-bis (4-hydroxyphenyl) heptane,
2,2-bis (4-hydroxyphenyl) nonane,
1,1-bis (4-hydroxyphenyl) decane,
1,1-bis (4-hydroxyphenyl) dodecane,
Etc. 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,
Etc. bis (hydroxyaryl) cycloalkanes;

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

4,4'-dihydroxydiphenyl sulfide,
Dihydroxy diaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfide;

Dihydroxy diaryl sulfoxides such as 4,4'-dihydroxy diphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfoxide;

4,4'-dihydroxydiphenyl sulfone,
Dihydroxy diaryl sulfones such as 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfone;
Etc.

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

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

  Cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4- (2-hydroxyethyl) cyclohexanol, 2,2,4,4, Cycloalkane diols 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- Aralkyl diols 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 -Cyclic ethers such as 1,2-epoxycyclohexane, 2,3-epoxy norbornane, and 1,3-epoxypropane; and the like.

  Among the monomers used as the raw materials of polycarbonate resins, 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; bischloroformates of dihydroxy compounds, haloformates such as monochloroformates of dihydroxy compounds, and the like.

  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; biscarbonates of dihydroxy compounds; monocarbonates of dihydroxy compounds; cyclic carbonates And carbonates of dihydroxy compounds such as

-Manufacturing method of polycarbonate resin The manufacturing method of polycarbonate resin is not specifically limited, Arbitrary methods can be adopted. 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.
Among these methods, particularly preferred ones will be specifically described below.

-Interfacial polymerization method First, the case where polycarbonate resin is manufactured by the interfacial polymerization method is explained.
In the interfacial polymerization method, after the dihydroxy compound is reacted with a carbonate precursor (preferably phosgene) in the presence of an organic solvent inert to the reaction and an alkaline aqueous solution, the pH is usually maintained at 9 or more. The polycarbonate resin is obtained by performing interfacial polymerization in the presence. In addition, in the reaction system, a molecular weight modifier (end stopper) may be present if necessary, and an antioxidant may be present to prevent oxidation of the dihydroxy compound.

  The dihydroxy compound and the carbonate precursor are as described above. Among the carbonate precursors, it is preferable to use phosgene, and a method using phosgene is particularly called phosgene method.

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

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

  Although the concentration of the alkali compound in the aqueous alkali solution is not limited, it is usually used at 5 to 10% by mass in order to control the pH in the aqueous alkali solution of the reaction to 10 to 12. For example, when blowing in phosgene, 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. It is preferable to set it as 1: 2.0 or more, usually 1: 3.2 or less, and in particular 1: 2.5 or less.

  Examples of the polymerization catalyst include aliphatic tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine and trihexylamine; and alicyclic resins such as N, N'-dimethylcyclohexylamine and N, N'-diethylcyclohexylamine Aromatic amines such as tertiary amines; N, N'-dimethylaniline, N, N'-diethylaniline; quaternary ammonium salts such as trimethylbenzyl ammonium chloride, tetramethyl ammonium chloride, triethyl benzyl ammonium chloride, etc. Pyridine; salts of guanidine; and the like. The polymerization catalyst may be used alone, or two or more may be used in any combination and ratio.

  Examples of the molecular weight modifier include aromatic phenols having a monohydric phenolic hydroxyl group; aliphatic alcohols such as methanol and butanol; mercaptan; phthalimide and the like, among which aromatic phenols are preferable. 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 phenols. Examples thereof include substituted phenols; vinyl group-containing phenols such as isopropenyl 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 modifier may be used 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  The amount of the molecular weight modifier used 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 can be obtained, and the appropriate order may be arbitrarily set. For example, when phosgene is used as the carbonate precursor, the molecular weight modifier can be mixed at any time between the time of the reaction between the dihydroxy compound and phosgene (phosgenation) and the time of the polymerization reaction start.
The reaction temperature is usually 0 to 40 ° C., and the reaction time is usually several minutes (eg, 10 minutes) to several hours (eg, 6 hours).

Melt Transesterification Method Next, the case of producing a polycarbonate resin by a melt transesterification method will be described.
In the melt transesterification method, for example, a transesterification reaction of carbonic acid diester with a dihydroxy compound is performed.

The dihydroxy compound is as described above.
On the other hand, as a carbonic diester, for example, dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate, di-tert-butyl carbonate and the like; diphenyl carbonate; substituted diphenyl carbonates such as ditolyl carbonate and the like can be mentioned. Among them, diphenyl carbonate and substituted diphenyl carbonate are preferable, and particularly diphenyl carbonate is more preferable. One carbonic diester may be used, or two or more carbonic diesters may be used in any combination and ratio.

  The ratio between the dihydroxy compound and the carbonic diester is arbitrary as long as the desired polycarbonate resin can be obtained, but it is preferable to use an equal molar amount or more of the carbonic diester with respect to 1 mol of the dihydroxy compound, and more preferably 1.01 mol or more Is more preferred. The upper limit is usually 1.30 moles 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 greatly affect the thermal stability, hydrolysis stability, color tone and the like. Therefore, the amount of terminal hydroxyl groups may be adjusted as necessary by any known method. In the transesterification reaction, a polycarbonate resin in which the amount of terminal hydroxyl groups is adjusted can usually be obtained by adjusting the mixing ratio of the carbonic diester and the aromatic dihydroxy compound; the degree of pressure reduction at the time of the transesterification reaction. In addition, the molecular weight of the polycarbonate resin usually obtained can also be adjusted by this operation.

When adjusting the mixing ratio of carbonic diester and dihydroxy compound to adjust the amount of terminal hydroxyl groups, the mixing ratio is as described above.
Further, as a more positive adjustment method, a method of mixing an end terminator separately at the time of reaction may be mentioned. Examples of the terminal stopper at this time include monohydric phenols, monohydric carboxylic acids, carbonic diesters and the like. In addition, 1 type may be used for end terminator and 2 or more types may be used together by arbitrary combinations and a ratio.

  In the production of a polycarbonate resin by a melt transesterification method, a transesterification catalyst is usually used. Any transesterification catalyst can be used. Among them, it is preferable to use, for example, an alkali metal compound and / or an alkaline earth metal compound. In addition, for example, basic 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 2 or more types may be used together by arbitrary combinations and a ratio.

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

  The melt polycondensation reaction can be carried out either batchwise or continuously. When carrying out by a batch system, 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, and what is necessary is just to set an appropriate order arbitrarily. However, in consideration of the stability of the polycarbonate resin, it is preferable to carry out the melt polycondensation reaction continuously.

  In the melt transesterification method, if necessary, a catalyst deactivator may be used. As the catalyst deactivator, a compound that neutralizes the transesterification catalyst can be optionally used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof. The catalyst deactivator may be used alone or in combination of two or more at any ratio and ratio.

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

The molecular weight of the polycarbonate resin (A) is preferably 10,000 to 15,000 by viscosity average molecular weight (Mv) converted from solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. Preferably, it is 10,500 or more, more preferably 11,000 or more, in particular 11,500 or more, most preferably 12,000 or more, and more preferably 14,500 or less. By setting the viscosity average molecular weight to the lower limit value or more of the above range, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, and by setting the viscosity average molecular weight to the upper limit value or less of the above range The flowability of the polycarbonate resin composition of the present invention can be suppressed and improved, and the molding processability can be enhanced to facilitate thin-wall molding.
In addition, you may mix and use 2 or more types of polycarbonate resin from which a viscosity average molecular weight differs, and in this case, you may mix the polycarbonate resin whose viscosity average molecular weight is out of said preferable range.

In addition, with viscosity average molecular weight [Mv], using methylene chloride as a solvent, the intrinsic viscosity [ロ ー] (unit dl / g) at a temperature of 20 ° C. is determined using a Ubbelohde viscometer, and Schnell's viscosity formula, ie, , = 1 = 1.23 × 10 ⁻⁴ Mv ^0.83 . In addition, the intrinsic viscosity [η] is a value calculated by measuring the specific viscosity [で_sp ] at each solution concentration [C] (g / dl) according to the following equation.

  The terminal hydroxyl group concentration of the polycarbonate resin is arbitrary and may be appropriately selected and determined, but is usually 1000 ppm or less, preferably 800 ppm or less, more preferably 600 ppm or less. This can further improve the retention heat stability and color tone of the polycarbonate resin. The lower limit is usually 10 ppm or more, preferably 30 ppm or more, and 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 property of a resin composition can be improved more.

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

  Polycarbonate resin is not limited to an embodiment including polycarbonate resin alone (polycarbonate resin alone is not limited to one including only one kind of polycarbonate resin, for example, it is used in a sense including an embodiment including plural kinds of polycarbonate resins different in monomer composition and molecular weight from each other) And may be used in combination with alloys (mixtures) of polycarbonate resins and other thermoplastic resins. Furthermore, for example, in order to further enhance flame retardancy and impact resistance, polycarbonate resin is copolymerized with an oligomer or polymer having a siloxane structure; phosphorus atom for the purpose of further enhancing thermal oxidation stability and flame retardancy Copolymers with monomers, oligomers or polymers having the formula; Copolymers with monomers, oligomers or polymers having the dihydroxyanthraquinone structure for the purpose of improving the thermal oxidation stability; polystyrene etc. to improve the optical properties Copolymer with an oligomer or polymer having an olefin structure; copolymer with a polyester resin oligomer or polymer for the purpose of improving chemical resistance; or even a copolymer based on a polycarbonate resin Good.

  The polycarbonate resin may contain a polycarbonate oligomer in order to improve the appearance and fluidity of the molded article. 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 9000 or less. Furthermore, the content of the polycarbonate oligomer is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Furthermore, 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, it is preferable that it is 80 mass% or less among polycarbonate resin, and it is more preferable that it is 50 mass% or less among regenerated polycarbonate resin. Since the recycled polycarbonate resin is highly likely to be degraded due to thermal degradation, aging degradation, etc., when such polycarbonate resin is used more than the above range, it is possible to lower the hue and mechanical properties. It is because there is sex.

[Polyalkylene Glycol Compound (B)]
The polycarbonate resin composition for thin-walled optical components of the present invention contains a polyalkylene glycol compound (B) having a number average molecular weight of 500 to 5,000, of which at least one end is sealed with an aryl group or an aralkyl group.

The polyalkylene glycol is an ether polymer composed of units derived from an alkylene glycol. The alkylene group may contain a branched structure, but is preferably a linear alkylene group.
The polyalkylene glycol is preferably a polymer composed of units derived from an alkylene glycol having 2 to 6 carbon atoms, and as such an alkylene glycol, for example, ethylene glycol, propylene glycol, butylene glycol, pentylene and the like Glycol, hexylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, neopentyl glycol, 3-methyl tetramethylene glycol, hexamethylene glycol and the like, and more preferably alkylene glycol having 3 to 6 carbon atoms, Propylene glycol, butylene glycol, trimethylene glycol and tetramethylene glycol are preferred.

  The polyalkylene glycol may be a homopolymer of a single alkylene glycol or a random copolymer or block copolymer of two or more alkylene glycols.

  Specific examples of polyalkylene glycols include polyethylene glycol, polypropylene glycol, polybutylene glycol, polypentylene glycol, polyhexylene glycol, polytrimethylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene Glycol etc. are preferably mentioned, and among them, polypropylene glycol, polybutylene glycol, polytrimethylene glycol and polytetramethylene glycol are preferable.

  The polyalkylene glycol compound (B) is characterized in that at least one end thereof is sealed with an aryl group or an aralkyl group. It seals at least one end, and may be either one end sealing or both end sealing.

  The aryl group is preferably an aryl group having preferably 6 to 22 carbon atoms, more preferably 6 to 12 carbon atoms, and still more preferably 6 to 10 carbon atoms, and examples thereof include a phenyl group, a tolyl group and a naphthyl group. Phenyl and tolyl are preferred. The end-capping group exhibits good compatibility with the polycarbonate even if it is an aralkyl group, and thus can exhibit the same action as the aryl group. The aralkyl group preferably has 7 to 23 carbon atoms, more preferably The aralkyl group preferably has 7 to 13 carbon atoms, more preferably 7 to 11 carbon atoms, and examples thereof include a benzyl group and a phenethyl group, with a benzyl group being particularly preferable.

  Examples of end-capped polyalkylene glycols (B) include, for example, polyethylene glycol monophenyl ether, polyethylene glycol diphenyl ether, polypropylene glycol monophenyl ether, polypropylene glycol diphenyl ether, polytrimethylene glycol monophenyl ether, polytriol. Methylene glycol diphenyl ether, polytetramethylene glycol monophenyl ether, polytetramethylene glycol diphenyl ether and the like are preferably mentioned, and those in which these phenyl groups are substituted by benzyl groups can likewise be mentioned as preferable specific examples.

  The polyalkylene glycol compound (B) in which one end is sealed with an aryl group or an aralkyl group is obtained by addition polymerization of an alkylene oxide to an alcohol having an aryl group such as a phenyl group or the like and an aralkyl group such as a benzyl group. The addition polymerization of alkylene oxide is known and is not particularly limited, but is generally performed under an alkali catalyst such as sodium hydroxide, potassium hydroxide and the like. Also, a polyalkylene glycol compound (B) in which both ends are sealed with an aryl group or an aralkyl group can be produced by etherifying the terminal hydroxy group of polyalkylene glycol or polyalkylene glycol monophenyl ether. The etherification method is known and is not particularly limited. Generally, polyalkylene glycol is reacted with aryl halide or aralkyl in the presence of sodium metal, sodium hydride, sodium hydroxide and the like, etc. Can be mentioned.

The number average molecular weight of the polyalkylene glycol compound (B) whose end is capped with an aryl group or an aralkyl group is in the range of 500 to 5,000, preferably 700 or more, more preferably 800 or more, preferably It is 4,000 or less, more preferably 3,000 or less. If the upper limit of the above range is exceeded, the compatibility is lowered, which is not preferable. If the lower limit of the above range is not reached, a gas is generated during molding, which is not preferable.
In addition, the number average molecular weight of a polyalkylene glycol compound (B) is a number average molecular weight computed based on the hydroxyl value measured based on JISK1577.

  The content of the polyalkylene glycol compound (B) is 0.2 to 4 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). The preferred content is 0.25 parts by mass or more, more preferably 0.3 parts by mass or more, preferably 3.5 parts by mass or less, more preferably 3 parts by mass or less, still more preferably 2.5 parts by mass or less is there. When the content is less than 0.2 parts by mass, the improvement of the hue and yellowing is not sufficient. When the content is more than 4 parts by mass, the resin becomes clouded and the transparency can not be maintained.

[Epoxy compound]
The resin composition of the present invention preferably contains an epoxy compound.
As the epoxy compound, 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'-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexylmethyl -3 ', 4'-Epoxy-6'-methylcyclohexylcarboxylate, 2,3-epoxycyclohexylmethyl-3', 4'-epoxycyclohexylcarboxylate, 4- (3,4-epoxy-5-methylcyclohexyl) Butyl-3 ', 4'-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6' -Methyl hexyl carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether, bis- Epoxy ethylene glycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenyl ethylene epoxide, octyl epoxy tallow, 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-epoxycyclohexyl carboxy , N-butyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexylcarboxylate, 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'-epoxycyclohexyl carboxylate, 4,5-epoxy tetrahydrophthalic anhydride, 3-t-butyl-4,5-epoxy tetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyldicarboxy Rate, di-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.
The epoxy compounds may be used alone or in combination of two or more.

  The content of the epoxy compound is preferably 0.0005 to 0.2 parts by mass, more preferably 0.001 parts by mass or more, still more preferably 0.003 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). The amount is preferably at least 0.005 parts by mass, more preferably at most 0.15 parts by mass, still more preferably at most 0.1 parts by mass, particularly preferably at most 0.05 parts by mass. When the content of the epoxy compound is less than 0.0005 parts by mass, the hue and the heat discoloration resistance tend to be insufficient, and when it exceeds 0.2 parts by mass, the heat discoloration resistance is not only deteriorated but also the hue and Wet heat stability also tends to decrease.

[Additives, etc.]
The polycarbonate resin composition of the present invention, other than those described above, includes other heat stabilizers, antioxidants, release agents, UV absorbers, fluorescent brighteners, pigments, dyes, other polymers, flame retardants, impact resistance improvement Additives such as agents, antistatic agents, plasticizers, compatibilizers and the like can be included. These additives may be used alone or in combination of two or more. Among these, it is particularly preferable to contain a heat stabilizer and an antioxidant.

  The heat stabilizer is not particularly limited but, for example, phosphorus-based compounds are preferably mentioned. Any known phosphorus-based compound can be used. Specific examples include phosphorus oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid and polyphosphoric acid, sodium acid pyrophosphate, potassium acid pyrophosphate, metal acid pyrophosphates such as calcium acid pyrophosphate, and phosphoric acid Examples thereof include phosphates of Group 1 or 10 metals such as potassium, sodium phosphate, cesium phosphate and zinc phosphate, organic phosphate compounds, organic phosphite compounds, organic phosphonite compounds and the like.

  Among them, triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, Dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylene bis (4,6-di-tert-butylphenyl Organic phosphites such as octyl phosphite are preferred.

  The content of the heat stabilizer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, per 100 parts by mass of the polycarbonate resin (A). The amount is usually 1 part by mass or less, preferably 0.7 parts by mass or less, more preferably 0.5 parts by mass or less. If the amount of the heat stabilizer is too small, the heat stabilization effect may be insufficient. If the amount of the heat stabilizer is too large, the effect may plateau and the economy may not be economical.

  Moreover, as antioxidant, a hindered phenol type antioxidant is mentioned preferably, for example. As a specific example thereof, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate, thiodiethylene bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6-diylbis [3- (3,5-di-) tert-Butyl-4-hydroxyphenyl) propionamide], 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] ] Methyl] phosphonate, 3,3 ', 3 ", 5,5', 5" -hexa-tert-butyl-a, a ', a -(Mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl- 4-hydroxy-m-tolyl) propionate], hexamethylene bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-) tert-Butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-) Bis (octylthio) -1,3,5-triazin-2-ylamino) phenol and the like can be mentioned.

Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate are preferred. preferable. As such a phenolic antioxidant, specifically, for example, “IRGANOX 1010” (registered trademark, the same applies hereinafter) manufactured by BASF Japan Ltd., “IRGANOX 1076”, “ADEKASTAB AO-50” manufactured by ADEKA And “Adekastab AO-60” and the like.
In addition, 1 type may contain antioxidant and 2 or more types may be contained by arbitrary combinations and ratios.

  The content of the antioxidant is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 1 part by mass or less, preferably 0 based on 100 parts by mass of the polycarbonate resin (A). .5 parts by mass or less. If the content of the antioxidant is less than the lower limit of the above range, the effect as the antioxidant may be insufficient, and if the content of the antioxidant exceeds the upper limit of the above range, The effect may have plateaued and may not be economical.

[Method of producing polycarbonate resin composition]
There is no restriction on the method for producing the polycarbonate resin composition of the present invention, and any known method for producing the polycarbonate resin composition can be widely adopted, and the polycarbonate resin (A) and the polyalkylene glycol compound (B), and if necessary, blending The other components to be mixed are premixed using various mixers such as tumblers and Henschel mixers, for example, and then mixed with a mixer such as a Banbury mixer, roll, Brabender, single-screw kneading extruder, twin-screw kneading extruder, kneader, etc. The method of melt-kneading is mentioned. The melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320 ° C.

The polycarbonate resin composition for thin optical parts of the present invention exhibits high spectral transmittance, and the spectral transmittance at a wavelength of 400 nm measured with an optical path length of 300 mm is preferably 30% or more, more preferably 31% or more It can preferably have a high spectral transmittance of 32% or more.
The spectral transmittance at a wavelength of 400 nm is the transmittance in the wavelength range close to the wavelength range of the blue LED, which is also frequently used in optical components such as light guide plates, and yellowish if the transmittance in this wavelength range is low. It will increase.
The spectral transmittance at a wavelength of 400 nm is measured with an optical path length of 300 mm using an injection-molded long optical path molded product (300 mm × 7 mm × 4 mm), and specifically, it is performed according to the method described in the examples described later. .

[Thin optical parts]
The polycarbonate resin composition for thin-walled optical components of the present invention can be manufactured into thin-walled optical components by molding pellets obtained by pelletizing the polycarbonate resin composition described above by various molding methods. Alternatively, the resin melt-kneaded by an extruder may be directly molded into a thin optical component without passing through pellets.

The polycarbonate resin composition of the present invention is excellent in fluidity and is excellent in appearance of molded articles without white point foreign matter even when it is formed into a thin-walled molded article, and it is compatible with transmittance and hue. It is suitably used to mold an optical component. It is preferable to shape | mold by resin temperature higher than 260-300 degreeC which is a temperature generally applied to injection molding of polycarbonate resin generally at the time of injection molding, and the resin temperature of 305-380 degreeC is preferable. The resin temperature is more preferably 310 ° C. or more, further preferably 315 ° C. or more, particularly preferably 320 ° C. or more, and more preferably 370 ° C. or less. When a conventional polycarbonate resin composition is used, there is also a problem that when the resin temperature at the time of molding is raised to mold a thin-walled molded article, white point foreign matter is easily generated on the surface of the molded article. By using the resin composition of the present invention, it is possible to produce a thin-walled molded article having a good appearance even in the above temperature range.
In addition, with resin temperature, when it is difficult to measure directly, it is grasped as barrel preset temperature.

  In the present invention, a thin-walled molded article refers to a molded article in which the thickness of its main portion is less than 1 mm. Here, the main portion means a portion exceeding 60% in the area of the molded article. The thickness of the main part is preferably 0.8 mm or less, more preferably 0.6 mm or less. The main part refers to a plate-like part or the like, and the plate-like part may be a flat plate or a curved plate, may be a flat surface, or may have irregularities or the like on the surface. Also, the cross section may have an inclined surface, or may be a bowl-shaped cross section or the like, or may be a rib shape or the like.

Thin-walled optical components include parts of devices and appliances that directly or indirectly use light sources such as LEDs, organic EL, incandescent lamps, fluorescent lamps, and cathode tubes, and light guide plates and members for surface light emitters are typical. It is illustrated as a thing.
The light guide plate is for guiding the light of a light source such as an LED among liquid crystal backlight units, various display devices, and lighting devices, and the light introduced from the side surface or the back surface is usually provided on the front surface Diffuse by the asperity, and give out uniform light. The shape is usually flat and may or may not have asperities on the surface.
The formation of the light guide plate is usually performed preferably by an injection molding method, a super high speed injection molding method, an injection compression molding method, or the like.
A light guide plate molded using the resin composition of the present invention is free from white turbidity and a decrease in transmittance, is extremely excellent in transmittance and hue, and is excellent in heat-resistant discoloration.

  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, various types of portable terminals such as tablet terminals, cameras, watches, notebook computers, various displays, lighting devices, etc. Be

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

Raw materials and evaluation methods used in the following examples and comparative examples are as follows.
In addition, the viscosity average molecular weight of polycarbonate resin (A) measured the intrinsic viscosity [eta] in methylene chloride at 20 degreeC using the Ubbelohde viscometer, and was calculated | required from the following formula | equation.
[Η] = 1.23 × 10 ⁻⁴ × (Mv) ^0.83

(Examples 1 to 6, Comparative Examples 1 to 4)
[Production of Resin Composition Pellets]
The components described above are compounded in proportions (parts by mass) described in Table 2 and mixed in a tumbler for 20 minutes, and then a vented single-screw extruder with a screw diameter of 40 mm ("VS-40" manufactured by Tanabe Plastic Machinery Co., Ltd.) The mixture was melt-kneaded at a cylinder temperature of 240 ° C. to obtain pellets by strand cutting.

[Measurement of hue (YI) and light transmittance]
The obtained pellets are dried at 120 ° C. for 5 to 7 hours with a hot air circulating drier, and then the resin temperature is 340 ° C. and the mold temperature is 80 ° C. by an injection molding machine (“EC100SX-2A” manufactured by Toshiba Machine Co., Ltd.) A long optical path molded product (300 mm × 7 mm × 4 mm) was molded.
The long light path molded product was visually observed to determine whether it was transparent or cloudy.
Further, with respect to this long optical path molded product, measurement of YI (yellowing degree) and spectral transmittance (unit:%) of wavelength 400 nm was performed at an optical path length of 300 mm. For measurement, a long path spectral transmission colorimeter (“ASA 1” manufactured by Nippon Denshoku Kogyo Co., Ltd., C light source, 2 ° visual field) was used.
Further, after heat treatment at 95 ° C. for 250 hours, measurement of YI and 400 nm spectral transmittance was performed, and the difference between before and after heat treatment was evaluated as ΔYI and Δ400 nm transmittance. The larger the negative amount of Δ400 nm transmittance, the more the yellowing progresses.
The above evaluation results are shown in Table 2 below.

As is clear from Table 2, the molded articles of the examples show that YI is small at a long optical path length of 300 mm, and yellowing is small. Furthermore, it is understood that the light transmittance at 400 nm is also high, the transparency is also excellent, and the ΔYI and Δ400 nm transmittances are also small.
On the other hand, in the comparative example, it is understood that YI of 300 mm is worse than that of the example. Furthermore, it is understood that the light transmittance is also low, and the ΔYI and Δ400 nm transmittances are large.
Therefore, the object of the present invention to provide a polycarbonate resin composition for thin-walled optical parts which has good transmittance and hue and is excellent in heat-resistant discoloration is to be achieved only when all the requirements of the present invention are satisfied. I understand that.

  The polycarbonate resin composition of the present invention has extremely good transmittance and hue and is excellent in heat-resistant discoloration, so it can be used extremely suitably for thin-walled optical parts, and its industrial applicability is very high.

Claims (5)

  0.2 to 4 parts by mass of a polyalkylene glycol compound (B) having a number average molecular weight of 500 to 5000, at least one end of which is sealed with an aryl group or an aralkyl group, relative to 100 parts by mass of the polycarbonate resin (A), A thin-walled optical component characterized in that 0.0005 to 0.2 parts by mass of an epoxy compound (C) is contained, and only one end of the polyalkylene glycol compound (B) is sealed with an aryl group or an aralkyl group. Polycarbonate resin composition.   The polycarbonate resin composition for thin optical parts according to claim 1, wherein the viscosity average molecular weight (Mv) of the polycarbonate resin (A) is 10,000 to 15,000. The thin-walled optical component which shape | molded the polycarbonate resin composition of Claim 1 or 2 . The thin-walled optical component according to claim 3 , which is a light guide plate having a thickness of 1 mm or less. According to claim 1 or 2 method for producing a thin optical component wall thickness less 1mm the polycarbonate resin composition is injection molded at from 305 to 380 ° C. according to.