Polycarbonate resin composition

Abstract

A polycarbonate resin composition comprising 100 parts by mass of a polycarbonate resin (A) and 0.01 to 4 parts by mass of a polylactone-polyether copolymer (B).

Description

[Technical field]

[0001] The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin composition which has a good hue, is excellent in transparency, and causes very little gas generation and mold contamination during molding, and to a molded article obtained by molding the same. [Background technology]

[0002] Liquid crystal display devices used in personal computers, mobile phones, etc. incorporate planar light source devices to meet the demands for thinner, lighter, more energy-efficient, and higher definition. These planar light source devices are equipped with a wedge-shaped light guide plate with a uniformly inclined surface on one side or a flat light guide plate for the purpose of guiding the incoming light uniformly and efficiently to the liquid crystal display side. Some planar light source devices are provided with a light scattering function by forming an uneven pattern on the surface of the light guide plate.

[0003] Such light guide plates are obtained by injection molding of thermoplastic resin, and the above-mentioned uneven pattern is imparted by transferring uneven parts formed on the surface of a nesting mold. Light guide plates have been molded from resin materials such as polymethyl methacrylate (PMMA), but in recent years, there has been a demand for display devices that can project clearer images, and the inside of devices tends to become hotter due to heat generated near the light source, so light guide plates are being replaced with polycarbonate resin materials that have higher heat resistance.

[0004] Polycarbonate resin has excellent mechanical properties, thermal properties, electrical properties, and weather resistance, but its light transmittance is lower than PMMA, etc., so when a surface light source is constructed from a light guide plate and a light source made of polycarbonate resin, the brightness is low. Recently, there has been a demand to reduce the chromaticity difference between the light entrance part of the light guide plate and the place away from the light entrance part, but polycarbonate resin has a problem of yellowing more easily than PMMA.

[0005] In order to improve the transmittance and hue, it has been proposed in Patent Document 1 to blend a polyalkylene glycol composed of a linear alkyl group into a polycarbonate resin. By blending polytetramethylene ether glycol, improvements in transmittance and yellowing index (YI) have been observed.

[0006] In particular, in recent mobile terminals such as smartphones and tablet terminals, optical components such as light guide plates have been getting thinner and larger at a remarkable speed, and high barrel temperatures and high-speed injection are required for molding light guide plates. As a result, the amount of gas generated during molding increases, and the problem of mold contamination is easily promoted. Therefore, the resin compositions used in these moldings are required to have not only excellent hue (YI) and transparency, but also low mold contamination due to gas generation during injection molding at high temperatures and excellent impact resistance. Furthermore, particularly in the case of edge-light type light guide plates, monitors are becoming significantly larger, thinner, and more powerful, and there is a demand for further improvements in the transparency, color, and mold contamination resistance of light guide plates. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5699188 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a polycarbonate resin composition which has a good hue, is excellent in transparency, produces very little gas generation and mold contamination during molding, and is also excellent in impact resistance. [Means for solving the problem]

[0009] Means for Solving the Problems The present inventors have conducted extensive research in order to achieve the above object, and as a result have found that by blending a specific amount of a polylactone-polyether copolymer with a polycarbonate resin, a polycarbonate resin composition can be obtained which has a good hue, is excellent in transparency, produces very little gas generation and mold contamination during molding, and also has excellent impact resistance, and have thus completed the present invention. The present invention relates to the following polycarbonate resin composition and molded article.

[0010] 1. A polycarbonate resin composition comprising 100 parts by mass of a polycarbonate resin (A) and 0.01 to 4 parts by mass of a polylactone-polyether copolymer (B). 2. The polycarbonate resin composition according to the above item 1, wherein the molar ratio of polylactone units to polyether units in the polylactone-polyether copolymer (B) is 5:95 to 95:5. 3. The polycarbonate resin composition according to the above 1 or 2, wherein the polylactone-polyether copolymer (B) is a polycaprolactone-polyether copolymer.

[0011] 4. The polycarbonate resin composition according to any one of the above 1 to 3, wherein the polycaprolactone-polyether copolymer (B) is a polycaprolactone-polyether copolymer represented by the following general formula (I) or (II): [ka] [ka] (In formulas (I) and (II), R1 to R4 each represent a linear or branched hydrocarbon group having 2 to 20 carbon atoms which may be substituted with an aryloxy group or an alkoxy group, and R5 represents CH2CHCH2, CH3C(CH2)3, or CH3CH2C(CH2)3. a represents an integer of 3 or more, b and c each represent an integer of 1 or more, l, m, and n each represent an integer of 1 or more, and o, p, and q each represent an integer of 1 or more.) 5. The polycarbonate resin composition according to 4 above, wherein R1 to R4 in said general formulas (I) and (II) are alkylene groups selected from the group consisting of 1,2-ethylene groups, 1,2-propylene groups, trimethylene groups, 1,2-butylene groups and tetramethylene groups.

[0012] 6. The polycarbonate resin composition according to any one of 1 to 5 above, wherein the polylactone-polyether copolymer (B) has a number average molecular weight (Mn) of 200 to 10,000. 7. The polycarbonate resin composition according to any one of the above 1 to 6, wherein the polycarbonate resin (A) has a viscosity average molecular weight (Mv) of 10,000 to 50,000. 8. The polycarbonate resin composition according to any one of 1 to 7 above, further comprising 0.005 to 0.5 parts by mass of a phosphorus-based stabilizer (C) per 100 parts by mass of the polycarbonate resin (A). 9. The polycarbonate resin composition according to the above item 8, wherein the phosphorus-based stabilizer (C) is a phosphorus-based compound having a phosphite structure. 10. The polycarbonate resin composition according to the above item 8 or 9, wherein the phosphorus-based stabilizer (C) contains two or more phosphorus-based compounds having a phosphite structure, at least one of which is a phosphite-based stabilizer having a spiro ring skeleton. 11. The polycarbonate resin composition according to any one of 1 to 10 above, further comprising an epoxy compound and / or an oxetane compound (D) in an amount of 0.0005 to 0.2 part by mass per 100 parts by mass of the polycarbonate resin (A). 12. The polycarbonate resin composition according to any one of 1 to 11 above, further comprising 0.01 to 0.5 parts by mass of a fatty acid ester (E) per 100 parts by mass of the polycarbonate resin (A). 13. A pellet made of the polycarbonate resin composition according to any one of 1 to 12 above. 14. A molded article obtained by molding the pellets described in 13 above. 15. The molded article according to the above item 14, which is an optical component. Effect of the Invention

[0013] The polycarbonate resin composition of the present invention has a good hue, excellent transparency, and is extremely low in gas generation and mold contamination during molding, and is also excellent in impact resistance. The molded article made of the polycarbonate resin composition of the present invention has a low YI value, excellent hue, and good transparency, and is therefore particularly suitable as an optical part. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a plan view of a teardrop-shaped mold used in the evaluation of mold contamination in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the present invention will be described in detail with reference to embodiments and examples. In this specification, unless otherwise specified, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0016] The polycarbonate resin composition of the present invention is characterized by containing 0.01 to 4 parts by mass of a polylactone-polyether copolymer (B) based on 100 parts by mass of a polycarbonate resin (A). Hereinafter, each component constituting the polycarbonate resin composition of the present invention, the molded article, etc. will be described in detail.

[0017] [Polylactone-polyether copolymer (B)] The polycarbonate resin composition of the present invention contains a polylactone-polyether copolymer (B). The polylactone-polyether copolymer (B) is a copolymer composed of units derived from a lactone compound and ether units or ether units derived from a polyglycol, and may be a random copolymer or a block copolymer. Preferably, it is a block copolymer composed of a polylactone block and a polyether block, and more preferably, it is a block copolymer in which a polylactone is linked to the end of a polyether.

[0018] The molar ratio of polylactone units to polyether units in the polylactone-polyether copolymer (B) is preferably 5:95 to 95:5, and more preferably 10:90 to 90:10. A polyether unit-rich copolymer having a molar ratio of polyether units of more than 50 is more preferred in terms of excellent hue, and the molar ratio of polylactone units to polyether units is preferably 10:90 to 45:55, 10:90 to 40:60, 10:90 to 35:65, and particularly preferably 10:90 to 30:70. The molar ratio of each unit in the polylactone-polyether copolymer (B) is measured using a 1H-NMR measuring device and 1,1,2,2-tetrachloroethylene-d2 as a solvent.

[0019] Examples of the lactone compound include cyclic lactone compounds such as ε-caprolactone, γ-butyrolactone, δ-valerolactone, β-propiolactone, and pivalolactone, which may be used alone or in combination. As the lactone compound, ε-caprolactone is particularly preferred.

[0020] The ether unit is expressed as -[R 1 -O]-, R 1 R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms which may be substituted with an aryloxy group or an alkoxy group. 1 may be substituted with an aryloxy or alkoxy group, and may have an aromatic ring, such as a 1-phenoxymethyl group.

[0021] R 1 is preferably a hydrocarbon group having 2 to 6 carbon atoms, particularly an alkylene group. Examples of the linear hydrocarbon group having 2 to 6 carbon atoms include a 1,2-ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group. Examples of the branched hydrocarbon group having 2 to 6 carbon atoms include a 1,2-propylene group, a 1,2-butylene group, a 2-methyl (1,2-propylene group), a 2,2-dimethyl (1,2-propylene group), a 1,2-dimethyl (1,2-propylene group), a 1-methyl (1,2-propylene group), a 1,2,2-trimethyl (1,2-propylene group), a 2-methyl (1,2-butylene group), a 1-methyl (1,2-butylene group), a 1-isopropylene (1,2-ethylene group), a 2-methyl, 1-isopropylene (1,2-ethylene group), a 1-tert-butyl (1,2-ethylene group), a 2-ethyl (1,2-butylene group), a 1-ethyl (1,2-butylene group), a 1,1-dimethyltrimethylene group, a 2-methyltetramethylene group, and a 1-methylpentylene group. R 1 Of these, 1,2-ethylene group, 1,2-propylene group, trimethylene group, 1,2-butylene group, and tetramethylene group are preferred, and 1,2-propylene group, trimethylene group, and tetramethylene group are particularly preferred. R 1 may be the same hydrocarbon group or may be composed of different hydrocarbon groups.

[0022] The method for producing the polylactone-polyether copolymer (B) is not particularly limited, and the copolymer can be produced by a known method. For example, a method in which a lactone compound is subjected to ring-opening polymerization and then esterification copolymerization (block copolymerization) with the above-mentioned polyether glycol or alkylene oxide having an ether unit is desirable.

[0023] During the copolymerization, a diol compound, a triol compound, or the like may be present. Examples of diol compounds include ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, 2-ethyl-2-n-butyl-1,3-propanediol, 2-ethyl-2-hexyl-1,3-propanediol, and cyclohexanedimethanol. Examples of the triol compound include glycerin, trimethylolethane, trimethylolpropane, butanetriol, pentanetriol, hexanetriol, heptanetriol, and octanetriol. Of these, glycerin and trimethylolpropane are preferred. When a triol compound is used, the polylactone-polyether copolymer (B) becomes a polymer having three branches.

[0024] The polycaprolactone-polyether copolymer (B) is preferably one represented by the following general formula (I) or (II). [ka] [ka] (In formulas (I) and (II), R1 to R4 each represent a linear or branched hydrocarbon group having 2 to 20 carbon atoms which may be substituted with an aryloxy group or an alkoxy group, and R5 represents CH2CHCH2, CH3C(CH2)3, or CH3CH2C(CH2)3. a represents an integer of 3 or more, b and c each represent an integer of 1 or more, l, m, and n each represent an integer of 1 or more, and o, p, and q each represent an integer of 1 or more.)

[0025] In general formulas (I) and (II), l, m, and n are each an integer of 1 or more, preferably 1 to 100, more preferably 3 or more, even more preferably 5 or more, and particularly preferably 10 or more, and are more preferably 90 or less, even more preferably 80 or less, among which 70 or less, 60 or less, 50 or less, 45 or less, 40 or less, and particularly preferably 35 or less. Furthermore, o, p, and q are each an integer of 1 or more, preferably 1 to 100, more preferably 3 or more, even more preferably 5 or more, and particularly preferably 10 or more, and more preferably 90 or less, even more preferably 80 or less, among which 70 or less, 60 or less, 50 or less, 45 or less, 40 or less, and particularly preferably 35 or less. a is an integer of 3 or more, preferably 3 to 100, more preferably 3 or more, even more preferably 5 or more, particularly preferably 10 or more, more preferably 90 or less, even more preferably 80 or less, among which 70 or less, 60 or less, 50 or less, 45 or less, 40 or less, particularly preferably 35 or less. b and c are each an integer of 1 or more, preferably 1 to 100, more preferably 3 or more, even more preferably 5 or more, particularly preferably 10 or more, more preferably 90 or less, even more preferably 80 or less, among which 70 or less, 60 or less, 50 or less, 45 or less, 40 or less, particularly preferably 35 or less.

[0026] R1 to R4 are straight-chain or branched hydrocarbon groups having 2 to 20 carbon atoms, which may be substituted with an aryloxy group or an alkoxy group. For example, they may have an aromatic ring, such as a 1-phenoxymethyl group. R1 to R4 are the same as the [R 1 -O]R 1 Preferable examples of R1 to R3 are the same as those shown below. R1 to R3 are preferably alkylene groups selected from a 1,2-ethylene group, a 1,2-propylene group, a trimethylene group, a 1,2-butylene group, and a tetramethylene group. Furthermore, R5 is CH2CHCH2, CH3C(CH2)3, or CH3CH2C(CH2)3, with CH2CHCH2 being particularly preferred. When l, m, and n are 2 or greater, R1 to R3 may be the same hydrocarbon group or different hydrocarbon groups.

[0027] The number average molecular weight (Mn) of the polylactone-polyether copolymer (B) is preferably 200 to 10,000, more preferably 300 or more, even more preferably 500 or more, and more preferably 5,000 or less, and even more preferably 4,500 or less. When the number average molecular weight is in such a range, compatibility with the polycarbonate resin (A) is excellent, and gas generation during molding is likely to be prevented. If the number average molecular weight exceeds the above upper limit, compatibility tends to decrease, and if the number average molecular weight is below the above lower limit, gas generation during molding is likely to occur. The number average molecular weight (Mn) of the polylactone-polyether copolymer (B) is a number average molecular weight (Mn) calculated based on the hydroxyl value measured in accordance with JIS K1577.

[0028] The content of the polylactone-polyether copolymer (B) is 0.01 to 4 parts by mass relative to 100 parts by mass of the polycarbonate resin (A). By containing it in such a range, the obtained polycarbonate resin composition has a good hue, excellent transparency, extremely little gas generation and mold contamination during molding, and excellent impact resistance without a decrease in impact resistance. The content is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.3 parts by mass or more, and is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less. If the content of the polyether compound (B) compound is less than the above lower limit or exceeds the above upper limit, the color of the obtained molded article tends to be inferior.

[0029] [Polycarbonate resin (A)] The polycarbonate resin (A) used in the present invention is not particularly limited, and various types can be used. Polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbons directly bonded to the carbonate bonds are aromatic carbons, and aliphatic polycarbonate resins in which the carbons directly bonded to the carbonate bonds are aliphatic carbons, and either type can be used. Among them, aromatic polycarbonate resins are preferred as the polycarbonate resin (A) from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

[0030] Among the monomers that are raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include: Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene; Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl;

[0031] dihydroxynaphthalenes such as 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;

[0032] dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, and 1,3-bis(4-hydroxyphenoxy)benzene;

[0033] 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 1,1-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C), 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-naphthylethan, 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;

[0034] 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;

[0035] 9,9-bis(4-hydroxyphenyl)fluorene, Cardo structure-containing bisphenols such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

[0036] 4,4'-dihydroxydiphenyl sulfide, Dihydroxydiaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; 4,4'-dihydroxydiphenyl sulfone, dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone; etc.

[0037] Of these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are particularly preferred. In particular, from the standpoint of impact resistance and heat resistance, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A) and 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C) are preferred. The aromatic dihydroxy compounds may be used alone or in any combination of two or more in any ratio.

[0038] Among the monomers that are raw materials for polycarbonate resins, examples of carbonate precursors include carbonyl halides, carbonate esters, etc. The carbonate precursors may be used alone or in any combination and ratio of two or more.

[0039] Specific examples of carbonyl halides include phosgene; haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds; and the like.

[0040] Specific examples of carbonate esters 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, and carbonates of dihydroxy compounds such as cyclic carbonates.

[0041] The method for producing the polycarbonate resin (A) is not particularly limited, and any method can be adopted. Examples of the method include interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers. Among these, the interfacial polymerization and melt transesterification methods are preferred because they have a higher effect of improving resistance to moist heat, and the interfacial polymerization method is particularly preferred.

[0042] The polycarbonate resin (A) used in the present invention may be a polycarbonate resin having a terminal structure represented by the following formula (1) as a part or all of it. [ka]

[0043] In the above formula (1), n ​​is an integer of 0 or 1, and R 1 is an alkyl group having 4 to 14 carbon atoms. When the polycarbonate resin has the terminal structure of the above formula (1), high fluidity is possible while maintaining strength, and high fluidity can be achieved even when a desired molecular weight is adopted without lowering the molecular weight of the polycarbonate resin, thereby enabling high impact resistance and high impact resistance at low temperatures.

[0044] R 1 The number of carbon atoms in the alkyl group of R is preferably 4 or 6 or more, and more preferably 12 or less, and even more preferably 10 or less. 1 The alkyl group may be linear or branched. Among them, R 1 is preferably one or more selected from the group consisting of a t-butyl group, an n-octyl group, an iso-octyl group, and a t-octyl group, more preferably a t-butyl group or a t-octyl group, and the terminal structure in general formula (1) is preferably a t-octylphenyl group (i.e., a 1,1,3,3-tetramethylbutylphenyl group).

[0045] In the above formula (1), -(O) bonded to a phenyl group n R1 The position of the group may be the ortho, meta or para position, but the para position shown in the following formula (1') is preferable. [ka]

[0046] R represented by the above formula (1) or (1') 1 Specific preferred examples of the group include alkylphenyl groups such as pt-butyl group, p-pentylphenyl group, p-hexylphenyl group, p-heptylphenyl group, pn-octylphenyl group, p-iso-octylphenyl group, pt-octylphenyl group, p-dodecylphenyl group, p-tetradecylphenyl group, p-nonylphenol, p-dodecylphenol, amylphenol, hexylphenol, heptylphenol, octylphenol, nonylphenol, decylphenol, dodecylphenol, and myristylphenol, and alkoxyphenyl groups such as p-hexyloxyphenyl group, pn-octyloxyphenyl group, p-iso-octyloxyphenyl group, pt-octyloxyphenyl group, and p-dodecyloxyphenyl group. R represented by formula (1) or (1') 1 Of these, the groups are preferably pt-butyl, n-octyl, iso-octyl and t-octyl, more preferably pt-butyl, pn-octyl, p-iso-octyl and pt-octyl, and particularly preferably pt-octyl, since it can achieve high fluidity and therefore high impact resistance and low-temperature impact resistance.

[0047] When the polycarbonate resin having the terminal structure of the above formula (1) is contained, the proportion thereof is preferably 40% by mass or more, and even preferably 100% by mass, in 100% by mass of the entire polycarbonate resin (A).

[0048] The molecular weight of the polycarbonate resin (A) is preferably 10,000 to 50,000, more preferably 10,000 to 40,000, even more preferably 10,000 to 30,000, 10,000 to 26,000, and even more preferably 10,500 or more, 11,000 or more, particularly preferably 11,500 or more, most preferably 12,000 or more, and even more preferably 24,000 or less, particularly preferably 20,000 or less. By making the viscosity average molecular weight equal to or 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 equal to or less than the upper limit of the above range, the decrease in the flowability of the polycarbonate resin composition of the present invention can be suppressed and improved, and the molding processability can be improved to facilitate molding process. Two or more kinds of polycarbonate resins having different viscosity average molecular weights may be mixed and used. In this case, polycarbonate resins having a viscosity average molecular weight outside the above-mentioned preferable range may be mixed.

[0049] The viscosity average molecular weight [Mv] is calculated by using methylene chloride as a solvent, measuring the intrinsic viscosity [η] (unit: dl / g) at 25°C using an Ubbelohde viscometer, and calculating the viscosity average molecular weight [Mv] using the Schnell viscosity formula, i.e., η = 1.23 × 10 -4 Mv 0.83 The intrinsic viscosity [η] is the value calculated from the specific viscosity [η sp ] was measured and the value was calculated according to the following formula.

number

[0050] In order to improve the appearance and flowability of the molded article, the polycarbonate resin (A) 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 oligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

[0051] Furthermore, the polycarbonate resin (A) may be not only a virgin raw material but also a polycarbonate resin regenerated from a used product (so-called material recycled polycarbonate resin), and it is also preferable to contain both a virgin raw material and a recycled resin, or it may be made of a recycled polycarbonate resin. When a recycled polycarbonate resin is used, the proportion of the recycled polycarbonate resin in the polycarbonate resin (A) is preferably 5% or more.

[0052] [Phosphorus-based stabilizer (C)] The polycarbonate resin composition of the present invention preferably contains a phosphorus-based stabilizer (C). By containing the phosphorus-based stabilizer, the color of the polycarbonate resin composition of the present invention becomes better, and the heat discoloration resistance is further improved. Any known phosphorus stabilizer can be used as the phosphorus stabilizer. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphates such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; phosphate compounds, phosphite compounds, and phosphonite compounds, and compounds having a phosphite structure are particularly preferred. By selecting a phosphite compound, a polycarbonate resin composition having higher discoloration resistance and continuous productivity can be obtained.

[0053] Here, the phosphite compound is a trivalent phosphorus compound having a structure represented by the general formula: P(OR)3, where R represents a monovalent or divalent organic group. Examples of such phosphite compounds include triphenyl phosphite, tris(mononylphenyl)phosphite, tris(mononyl / dinonyl phenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, monooctyldiphenyl phosphite, dioctyl monophenyl phosphite, monodecyldiphenyl 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-methylenebis(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]-dioxaphosphepine, and the like.

[0054] Among these phosphite compounds, aromatic phosphite compounds represented by the following formula (1) or (2) are more preferred because they effectively enhance the heat discoloration resistance of the polycarbonate resin composition of the present invention.

[0055] [ka] [In formula (1), R 1 , R 2 and R 3 may be the same or different and represent an aryl group having 6 to 30 carbon atoms.

[0056] [ka] [In formula (2), R 4 and R 5 may be the same or different and represent an aryl group having 6 to 30 carbon atoms.

[0057] Among the phosphite compounds represented by the above formula (1), triphenyl phosphite, tris(mononylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, etc. are preferred, and among them, tris(2,4-di-tert-butylphenyl) phosphite is more preferred.Specific examples of such organic phosphite compounds include "Adeka STAB 1178" manufactured by ADEKA Corporation, "Sumilizer TNP" manufactured by Sumitomo Chemical Co., Ltd., "JP-351" manufactured by Johoku Chemical Industry Co., Ltd., "Adeka STAB 2112" manufactured by ADEKA Corporation, "Irgafos 168" manufactured by BASF, and "JP-650" manufactured by Johoku Chemical Industry Co., Ltd.

[0058] As the phosphite compound represented by the above formula (2), those having a pentaerythritol diphosphite structure such as bis(2,4-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite are particularly preferred. Specific examples of such organic phosphite compounds include "ADEKA STAB PEP-36" and "ADEKA STAB PEP-24G" manufactured by ADEKA Corporation, and "Doverphos S-9228" manufactured by Doverchemical Co., Ltd.

[0059] Among the phosphite compounds, the aromatic phosphite compounds represented by the above formula (2) are more preferred because they have a more excellent hue. The phosphorus-based stabilizer may be contained either as one type or as two or more types in any combination and ratio.

[0060] The content of the phosphorus-based stabilizer (C) is preferably 0.005 to 0.5 parts by mass, more preferably 0.007 parts by mass or more, even more preferably 0.008 parts by mass or more, particularly preferably 0.01 parts by mass or more, and more preferably 0.4 parts by mass or less, even more preferably 0.3 parts by mass or less, among which, preferably 0.2 parts by mass or less, particularly 0.1 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin (A). When the content of the phosphorus-based stabilizer (C) is less than 0.005 parts by mass within the above range, the hue and heat discoloration resistance tend to be insufficient, and when the content of the phosphorus-based stabilizer (C) exceeds 0.5 parts by mass, the heat discoloration resistance tends to deteriorate and the wet heat stability tends to decrease.

[0061] [Epoxy compounds and / or oxetane compounds (D)] The resin composition of the present invention also preferably contains an epoxy compound and / or an oxetane compound (D). By containing the epoxy compound and / or the oxetane compound (D), the heat discoloration resistance can be further improved. The content of the epoxy compound and / or the oxetane compound (D) is preferably 0.0005 to 0.2 parts by mass relative to 100 parts by mass of the polycarbonate resin (A).

[0062] The epoxy compound may be a compound having one or more epoxy groups in one molecule. 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'-methylcyclohexyl carboxylate, 2,3-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate, 4-(3,4-epoxy-5-methylcyclohexyl)butyl-3',4'-epoxy, and the like may be used. bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene oxide, cyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6'-methylcyclohexylcarboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene oxide, ethylene glycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxy thalate, 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 carboxylate, N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl carbo xylate, 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'-epoxycyclohexyl carboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3-t-butyl-4,Preferred examples of the epoxy ester include 5-epoxytetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyldicarboxylate, di-n-butyl-3-t-butyl-4,5-epoxy-cis-1,2-cyclohexyldicarboxylate, epoxidized soybean oil, and epoxidized linseed oil.

[0063] Of these, alicyclic epoxy compounds are preferably used, and 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate is particularly preferred.

[0064] Also preferably usable are polyalkylene glycol derivatives having an epoxy group at one or both ends, and in particular, polyalkylene glycols having an epoxy group at both ends.

[0065] Preferred examples of the polyalkylene glycol derivatives containing an epoxy group in the structure include polyethylene glycol diglycidyl ether, poly(1-methyl)ethylene glycol diglycidyl ether, poly(2-ethyl)ethylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, polyethylene glycol-poly(1-methyl)ethylene glycol diglycidyl ether, polytetramethylene glycol-poly(2-methyl)ethylene glycol diglycidyl ether, and polytetramethylene glycol-poly(1-ethyl)ethylene glycol diglycidyl ether.

[0066] The epoxy compounds may be used alone or in combination of two or more kinds.

[0067] The content of the epoxy compound is preferably 0.0005 to 0.2 parts by mass relative to 100 parts by mass of the polycarbonate resin (A), but is more preferably 0.001 parts by mass or more, even more preferably 0.003 parts by mass or more, particularly preferably 0.005 parts by mass or more, and more preferably 0.15 parts by mass or less, even more preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less. If the content of the epoxy compound is less than 0.0005 parts by mass, the hue and heat discoloration resistance tend to be insufficient, and if it exceeds 0.2 parts by mass, the heat discoloration resistance tends to deteriorate, and the hue and moist heat stability tend to decrease.

[0068] As the oxetane compound, any compound having one or more oxetane groups in the molecule can be used, and both a monooxetane compound having one oxetane group in the molecule and a polyoxetane compound having two or more oxetane groups in the molecule and being bifunctional or higher can be used. By including an oxetane compound, it is possible to further improve good hue and high resistance to heat discoloration.

[0069] Preferred examples of the monooxetane compound include compounds represented by the following general formula (3), (4) or (5).

[0070] [ka] [ka] [In the above formulas (3) to (5), R 1 is an alkyl group, R 2 represents an alkyl group or a phenyl group, and R 3 represents a divalent organic group which may have an aromatic ring, and n represents 0 or 1.

[0071] In the above general formulas (3), (4) and (5), R 1 is an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably an ethyl group. Also, R 2 R is an alkyl group or a phenyl group, preferably an alkyl group having 2 to 10 carbon atoms, and may be any of a linear alkyl group, a branched alkyl group, and an alicyclic alkyl group, or may be a linear or branched alkyl group having an ether bond (an ether-type oxygen atom) in the middle of the alkyl chain. 2 Specific examples of R include an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, a 3-oxypentyl group, a cyclohexyl group, and a phenyl group. 2 is preferably a 2-ethylhexyl group, a phenyl group, or a cyclohexyl group.

[0072] Preferred specific examples of the compound of the above general formula (3) include 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxymethyl-3-n-butyloxetane, 3-hydroxymethyl-3-propyloxetane, etc. Among these, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, etc. are particularly preferred. A specific example of the compound of the above general formula (4) is particularly preferably 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane.

[0073] In the above general formula (5), R 3 is a divalent organic group which may have an aromatic ring, examples of which include linear or branched alkylene groups having 1 to 12 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, an n-pentamethylene group, and an n-hexamethylene group; a phenylene group; 2 -Ph-CH 2 -or-CH 2 -Ph-Ph-CH 2Examples of such a divalent group include a divalent group represented by the formula - (where Ph represents a phenyl group), a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol Z residue, a cyclohexanedimethanol residue, and a tricyclodecanedimethanol residue.

[0074] Particularly preferred specific examples of the compound of the above general formula (5) include bis(3-methyl-3-oxetanylmethyl)ether, bis(3-ethyl-3-oxetanylmethyl)ether, bis(3-propyl-3-oxetanylmethyl)ether, bis(3-butyl-3-oxetanylmethyl)ether, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, and 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene.

[0075] The oxetane compounds may be used alone or in combination of two or more kinds.

[0076] The content of the oxetane compound, when contained, is preferably 0.0005 to 0.2 parts by mass, more preferably 0.001 parts by mass or more, even more preferably 0.003 parts by mass or more, particularly preferably 0.005 parts by mass or more, and more preferably 0.15 parts by mass or less, even more preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin (A). When the content of the oxetane compound is less than 0.0005 parts by mass, the hue and heat discoloration resistance tend to be insufficient, and when it exceeds 0.2 parts by mass, the heat discoloration resistance tends to deteriorate and gas is easily generated during molding.

[0077] It is also preferable to contain both the epoxy compound and the oxetane compound in combination, and when both are contained, the total content is preferably 0.0005 to 0.2 parts by mass per 100 parts by mass of the polycarbonate resin (A).

[0078] [Fatty acid ester (E)] The resin composition of the present invention preferably contains a fatty acid ester (E). By containing the fatty acid ester (E), the color tone becomes good, which is preferable. The fatty acid ester (E) is an ester of an aliphatic carboxylic acid and an alcohol.

[0079] Examples of the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol include saturated or unsaturated aliphatic mono-, di- or tri-carboxylic acids. Here, the aliphatic carboxylic acid also includes alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are mono- or di-carboxylic acids having 6 to 36 carbon atoms, and more preferred are saturated aliphatic mono-carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetralinic acid, montanic acid, adipic acid, and azelaic acid.

[0080] Examples of the alcohol in the ester of an aliphatic carboxylic acid and an alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferred, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols having 30 or less carbon atoms are more preferred. Here, the term aliphatic is used to include alicyclic compounds. Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol.

[0081] The above ester may contain an aliphatic carboxylic acid and / or alcohol as an impurity. The above ester may be a pure substance, or may be a mixture of a plurality of compounds. The aliphatic carboxylic acid and alcohol that are combined to form an ester may each be used alone or in any combination and ratio of two or more.

[0082] Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

[0083] The content of the fatty acid ester (E) is preferably 0.01 to 0.5 parts by mass based on 100 parts by mass of the polycarbonate resin (A).

[0084] [Additives, etc.] The polycarbonate resin composition of the present invention may contain additives other than those described above, such as antioxidants, ultraviolet absorbers, fluorescent whitening agents, pigments, dyes, polymers other than polycarbonate resins, flame retardants, impact resistance improvers, antistatic agents, plasticizers, compatibilizers, etc. These additives may be blended alone or in combination of two or more. However, when a polymer other than the polycarbonate resin (A) is contained, the content thereof is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, per 100 parts by mass of the polycarbonate resin (A).

[0085] [Method for producing polycarbonate resin composition] There is no limitation on the method for producing the polycarbonate resin composition of the present invention, and a wide variety of known methods for producing polycarbonate resin compositions can be used, including a method in which the above-mentioned essential components and other components to be mixed as necessary are mixed in advance using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, a kneader, etc. The temperature for melt-kneading is not particularly limited, but is usually in the range of 240 to 320°C.

[0086] [Polycarbonate resin composition] The polycarbonate resin composition of the present invention has excellent hue and therefore excellent YI (yellowing index), and the initial YI value at an optical path length of 300 mm is preferably 23 or less, more preferably 22 or less, 21.5 or less, 21 or less, and further preferably 20.5 or less. The initial YI value is measured by molding a long optical path molded product (300mm x 7mm x 4mm) at a resin temperature of 340°C and a mold temperature of 80°C, and measuring the YI value (initial YI value) with an optical path length of 300mm, a C light source, and a 2° field of view.

[0087] [Optical components] The polycarbonate resin composition of the present invention can be pelletized and molded by various molding methods to produce optical parts. Alternatively, the resin melt-kneaded in an extruder can be directly molded into optical parts without going through the pelletizing process.

[0088] The polycarbonate resin composition of the present invention is excellent in fluidity and hue, and gas generation and mold contamination during molding are extremely low, so it is particularly suitable for use in molding optical components, particularly thin-walled optical components that are prone to mold contamination, by injection molding. The resin temperature during injection molding is preferably higher than 260 to 300 ° C, which is a temperature generally applied to injection molding of polycarbonate resins, particularly in the case of thin-walled molded bodies, and is preferably 305 to 400 ° C. The resin temperature is more preferably 310 ° C or higher, even more preferably 315 ° C or higher, particularly preferably 320 ° C or higher, and more preferably 390 ° C or lower. When a conventional polycarbonate resin composition is used, there is a problem that the molded body is prone to yellowing when the resin temperature during molding is increased to mold a thin-walled molded body, but by using the resin composition of the present invention, it is possible to produce molded bodies, particularly thin-walled optical components, having good hue and high transparency even in the above temperature range. When it is difficult to measure the resin temperature directly, the resin temperature is regarded as the barrel set temperature.

[0089] Here, the thin-walled molded product refers to a molded product having a plate-like 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 flat or curved, may have a flat surface or may have irregularities on the surface, and may have an inclined cross section or a wedge-shaped cross section.

[0090] The optical component may be in the form of a film or sheet, and a specific example of such a film or sheet is a light guide film.

[0091] In addition, suitable optical components include light guides and lenses that guide light from light sources such as LEDs in vehicle headlamps, rear lamps, fog lamps, etc. for automobiles or motorcycles, and the like, and the present invention can also be suitably used for these.

[0092] Optical components include parts of devices and appliances that directly or indirectly use light sources such as LEDs, organic electroluminescence (EL), incandescent lamps, fluorescent lamps, and cathode ray tubes, and representative examples include light guide plates and surface light emitter components. Light guide plates are used in liquid crystal backlight units and various display devices and lighting devices to guide light from light sources such as LEDs, and they usually diffuse the light entering from the side or back side by using irregularities on the surface to emit a uniform light. They are usually flat in shape, and the surface may or may not have irregularities. The light guide plate is usually formed by, preferably, injection molding, ultra-high speed injection molding, injection compression molding, melt extrusion molding (for example, T-die molding), or the like. A light guide plate molded using the resin composition of the present invention is free from cloudiness or reduced transmittance, has good hue and high transparency, and is less prone to molding defects due to mold contamination.

[0093] 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 various mobile terminals such as mobile phones, mobile notebooks, netbooks, slate PCs, tablet PCs, smartphones, and tablet-type terminals, cameras, watches, notebook computers, various displays, lighting equipment, etc. Among these, the light guide plate can be particularly suitably used as a high-performance edge-light type light guide plate, etc. EXAMPLES

[0094] The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited to the following examples. The raw materials used in the following Examples and Comparative Examples are as shown in Table 1.

[0095] [Table 1]

[0096] (Examples 1 to 15, Comparative Examples 1 to 7) [Production of resin composition pellets] The above-mentioned components were blended in the ratios (parts by mass) shown in Tables 2 and 3 below, mixed in a tumbler for 20 minutes, and then melt-kneaded at a cylinder temperature of 240°C using a vented single-screw extruder with a screw diameter of 40 mm (Tanabe Plastic Machinery Co., Ltd.'s "VS-40"), and pellets were obtained by strand cutting.

[0097] [Strand transparency during production of resin composition pellets] In the above-mentioned production process of the resin composition pellets, the transparency of the strands melt-kneaded and extruded by the extruder was visually judged according to the following criteria. A: The extruded strands have extremely high transparency, and the compatibility between the polycarbonate resin (A) and the polylactone-polyether copolymer (B) is extremely good. B: The extruded strand has high transparency and good compatibility between the polycarbonate resin (A) and the polylactone-polyether copolymer (B). C: The extruded strand is slightly cloudy, and the compatibility between the polycarbonate resin (A) and the polylactone-polyether copolymer (B) is poor. D: The extruded strand is strongly cloudy, and the compatibility between the polycarbonate resin (A) and the polylactone-polyether copolymer (B) is extremely poor.

[0098] [Gas generation during molding (mold contamination evaluation)] Evaluation of contamination during injection molding (mold contamination) The pellets obtained above were dried at 120°C for 5 hours, and then injection molded for 200 shots using an injection molding machine (Sumitomo Heavy Industries, Ltd., "SE7M") with a teardrop-shaped mold as shown in Figure 1 under conditions of a cylinder temperature of 340°C, a molding cycle of 10 seconds, and a mold temperature of 40°C. After molding, the condition of dirt due to white deposits that occurred on the metal mirror surface on the fixed side of the mold was visually evaluated and judged according to the following criteria. A: There is very little adhesion to the mold, and the mold contamination resistance is extremely good. B: There is little adhesion to the mold, but some resistance to mold contamination is observed. C: There is a relatively large amount of material adhering to the mold, and mold contamination is evident. D: There is a lot of material adhering to the mold, and mold contamination is evident.

[0099] The teardrop-shaped mold in Fig. 1 is designed to introduce the resin composition from gate G and to facilitate accumulation of generated gas at tip P. Gate G has a width of 1 mm and a thickness of 1 mm, and in Fig. 1, width h1 is 14.5 mm, length h2 is 7 mm, length h3 is 27 mm, and the thickness of the molded part is 3 mm.

[0100] [Hue (YI)] The obtained pellets were dried in a hot air circulation dryer at 120°C for 5 to 7 hours, and then molded into a long optical path molded product (300mm x 7mm x 4mm) using an injection molding machine (Sodick "HSP100A") at a resin temperature of 340°C and a mold temperature of 80°C. The long-light-path molded product was subjected to measurement of YI (yellowing index) at a light path length of 300 mm using a long-light-path spectrophotometer ("ASA 1" manufactured by Nippon Denshoku Industries Co., Ltd., C light source, 2° field of view).

[0101] The above evaluation results are shown in Table 2-3 below.

[0102] [Table 2]

[0103] [Table 3] [Industrial Applicability]

[0104] The polycarbonate resin composition of the present invention has a good hue, excellent transparency, extremely little gas generation and mold contamination during molding, and excellent impact resistance, and therefore can be extremely suitably used for various molded products, particularly optical parts.

Claims

1. A polycarbonate resin composition comprising 100 parts by mass of a polycarbonate resin (A), 0.01 to 4 parts by mass of a polylactone-polyether copolymer (B), and 0.005 to 0.5 parts by mass of a phosphorus-based stabilizer (C).

2. 2. The polycarbonate resin composition according to claim 1, wherein the molar ratio of polylactone units to polyether units in the polylactone-polyether copolymer (B) is from 5:95 to 95:

5.

3. 3. The polycarbonate resin composition according to claim 1, wherein the polylactone-polyether copolymer (B) is a polycaprolactone-polyether copolymer.

4. 4. The polycarbonate resin composition according to claim 3, wherein the polycaprolactone-polyether copolymer (B) is a polycaprolactone-polyether copolymer represented by the following general formula (I) or (II): 【Chemistry 1】 【Chemistry 2】 (In formulas (I) and (II), R1 to R4 each represent a linear or branched hydrocarbon group having 2 to 20 carbon atoms which may be substituted with an aryloxy group or an alkoxy group, and R5 represents CH ２ CHCH ２ , C.H. ３ C (CH ２ ) ３ , or C.H. ３ CH ２ C (CH ２ ) ３ a is an integer of 3 or more, b and c are each an integer of 1 or more, l, m, and n are each an integer of 1 or more, and o, p, and q are each an integer of 1 or more.

5. 5. The polycarbonate resin composition according to claim 4, wherein R1 to R4 in general formulas (I) and (II) are alkylene groups selected from the group consisting of a 1,2-ethylene group, a 1,2-propylene group, a trimethylene group, a 1,2-butylene group, and a tetramethylene group.

6. 3. The polycarbonate resin composition according to claim 1, wherein the polylactone-polyether copolymer (B) has a number average molecular weight (Mn) of 200 to 10,000.

7. 3. The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin (A) has a viscosity average molecular weight (Mv) of 10,000 to 50,000.

8. 2. The polycarbonate resin composition according to claim 1, wherein the phosphorus-based stabilizer (C) is a phosphorus-based compound having a phosphite structure.

9. 2. The polycarbonate resin composition according to claim 1, wherein the phosphorus-based stabilizer (C) contains two or more phosphorus-based compounds having a phosphite structure, at least one of which is a phosphite-based stabilizer having a spiro ring skeleton.

10. 3. The polycarbonate resin composition according to claim 1, further comprising an epoxy compound and / or an oxetane compound (D) in an amount of 0.0005 to 0.2 parts by mass per 100 parts by mass of the polycarbonate resin (A).

11. 3. The polycarbonate resin composition according to claim 1, further comprising a fatty acid ester (E) in an amount of 0.01 to 0.5 parts by mass per 100 parts by mass of the polycarbonate resin (A).

12. A pellet comprising the polycarbonate resin composition according to claim 1 or 2.

13. A molded article obtained by molding the pellet according to claim 12.

14. The molded article according to claim 13, which is an optical component.

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