Polycarbonate resin composition and molded article

Abstract

To provide a polycarbonate resin composition which has high flowability and a good hue, is excellent in transparency, and is extremely reduced in mold contamination due to gas generation during molding, and a molded article.SOLUTION: A polycarbonate resin composition contains, with respect to 100 pts.mass of a polycarbonate resin (A), 0.01-5 pts.mass of a polyether polycarbonate resin (B) having polyether and a carbonate bond. A weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8,000 to 40,000 in terms of polystyrene by gel permeation chromatography using chloroform as a solvent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polycarbonate resin composition and a molded article. [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 light guide plates have a light scattering function provided by forming an uneven pattern on the surface.

[0003] Such light guide plates are obtained by injection molding of thermoplastic resin, and the above-mentioned uneven pattern is imparted by transferring unevenness formed on the surface of a nesting mold. Conventionally, light guide plates have been molded from resin materials such as polymethyl methacrylate (PMMA), but recently, there has been a demand for display devices that can project clearer images, and as a result, the temperature inside the display device tends to rise due to heat generated near the light source. For this reason, the resin material of light guide plates is being replaced with polycarbonate resin material, which has higher heat resistance.

[0004] Generally, polycarbonate resin is a resin with excellent mechanical properties, thermal properties, electrical properties, and weather resistance. However, the light transmittance of polycarbonate resin is lower than that of resins used in conventional light guide plates, such as PMMA. Therefore, when a surface light source is constructed from a light guide plate made of polycarbonate resin and a light source, there is a problem that the brightness is low. In addition, there is a recent demand to reduce the chromaticity difference between the light entrance part of the light guide plate and a part away from the light entrance part, but polycarbonate resin has a problem that it is more likely to yellow than PMMA.

[0005] For example, Patent Document 1 proposes a method of improving light transmittance and brightness by adding an acrylic resin and an alicyclic epoxy compound to a polycarbonate resin. Patent Document 2 proposes a method of improving brightness by modifying the terminals of a polycarbonate resin to improve the transferability of the unevenness to a light guide plate. Patent Document 3 proposes a method of improving brightness by introducing a copolyestercarbonate having an aliphatic segment to improve the transferability.

[0006] However, in the method described in Patent Document 1, although the hue is improved by adding an acrylic resin, it is difficult to increase the light transmittance and brightness due to the clouding. Although the transmittance may be improved by adding an alicyclic epoxy compound, the effect of improving the hue is not observed. In the methods described in Patent Documents 2 and 3, although the effect of improving the fluidity and transferability of the resin constituting the light guide plate can be expected, there is a drawback in that the heat resistance is reduced.

[0007] On the other hand, it is known to blend compounds such as polyethylene glycol or poly(2-methyl)ethylene glycol into thermoplastic resins such as polycarbonate resins. For example, Patent Document 4 describes a polycarbonate resin that contains this compound and is resistant to gamma radiation. Patent Document 5 describes a thermoplastic resin composition that is made by blending this compound into a resin such as PMMA and has excellent antistatic properties and surface appearance.

[0008] Patent Document 6 proposes improving the transmittance and hue by blending a polyalkylene glycol composed of a linear alkyl group with a polycarbonate resin. For example, by blending polytetramethylene ether glycol with a polycarbonate resin, improvements in transmittance and yellowness (yellow index: YI) are observed.

[0009] Furthermore, Patent Document 7 describes a method for producing a polycarbonate copolymer using a diol obtained by diesterifying a polyalkylene glycol as a raw material (comonomer). The polycarbonate copolymer described in Patent Document 7 has an unstable diester diol of polyalkylene glycol, and the color tone and heat discoloration resistance are also poor. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 11-158364 [Patent Document 2] JP 2001-208917 A [Patent Document 3] JP 2001-215336 A [Patent Document 4] Japanese Patent Application Publication No. 1-22959 [Patent Document 5] Japanese Patent Application Publication No. 9-227785 [Patent Document 6] Patent No. 5699188 [Patent Document 7] JP 2006-016497 A Summary of the Invention [Problem to be solved by the invention]

[0011] In recent years, in the field of various information terminals such as smartphones, tablet terminals, and in-vehicle displays, the thinning and enlargement of optical components such as light guide plates are progressing at a remarkable speed. Molding of such optical components requires high barrel temperatures and high-speed injection. Accordingly, the resin composition used for molding the optical components is required to have not only excellent optical properties such as good hue and transparency, but also high fluidity suitable for injection molding. In addition, in injection molding at high temperatures, there is a risk of increasing the amount of gas generated from the resin composition, and in this case, a problem occurs in which mold contamination is likely to progress due to gas generation. For this reason, it is further required that the resin composition has less mold contamination due to gas generation during injection molding at high temperatures.

[0012] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polycarbonate resin composition and a molded article which have high fluidity and good hue, and further have excellent transparency, and which cause extremely little mold contamination due to gas generation during molding. [Means for solving the problem]

[0013] Means for Solving the Problems The present inventors have conducted extensive research to solve the above problems and have found that by blending a polyether polycarbonate resin having a molecular weight within a specific range with a polycarbonate resin in a specific ratio, a polycarbonate resin composition can be obtained which has high fluidity, good hue, excellent transparency, and extremely little mold contamination due to gas generation during molding, thereby completing the present invention.

[0014] That is, in order to solve the above-mentioned problems and achieve the object, the polycarbonate resin composition according to the present invention is characterized in that it contains 0.01 to 5 parts by mass of a polyether polycarbonate resin (B) having a polyether and a carbonate bond per 100 parts by mass of a polycarbonate resin (A), and the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8,000 to 40,000 in terms of polystyrene, as determined by gel permeation chromatography using chloroform as a solvent.

[0015] Moreover, the polycarbonate resin composition according to the present invention is characterized in that, in the above-mentioned invention, the polyether polycarbonate resin (B) is a copolymer represented by the following general formula (1).

[0016] [ka] (In general formula (1), R Z and R X R each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Z and R X There are multiple R Z and R X may be the same or different. i represents an integer of 2 to 10, p represents an integer of 1 to 600, and n represents an integer of 1 to 3000.

[0017] Further, in the polycarbonate resin composition according to the present invention, i in the general formula (1) is 3 or 4.

[0018] Moreover, in the above-mentioned invention, the polycarbonate resin composition according to the present invention is characterized in that it further contains 0.005 to 0.5 parts by mass of a phosphorus-based stabilizer (C) per 100 parts by mass of the polycarbonate resin (A).

[0019] Moreover, in the polycarbonate resin composition according to the present invention, in the above-mentioned invention, the weight average molecular weight (Mw) of the polyether constituting the polyether polycarbonate resin (B) is 600 to 8,000 in terms of polystyrene, as determined by gel permeation chromatography using chloroform as a solvent.

[0020] Moreover, the polycarbonate resin composition according to the present invention is characterized in that, in the above invention, the initial YI value of the polycarbonate resin composition at an optical path length of 300 mm is 25.0 or less, and the difference ΔYI between the YI value of the polycarbonate resin composition at an optical path length of 300 mm after being held at 95° C. for 1000 hours and the initial YI value is 6.5 or less.

[0021] A molded article according to the present invention is characterized in that it is made of the polycarbonate resin composition according to any one of the above inventions.

[0022] The molded article according to the present invention is characterized in that it is an optical component in the above invention. Effect of the Invention

[0023] The polycarbonate resin composition and molded article according to the present invention have high fluidity and good color, and further have excellent transparency, and are effective in extremely reducing mold contamination due to gas generation during molding. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram showing an example of a teardrop-shaped mold used for evaluating mold contamination in an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Preferred embodiments of the polycarbonate resin composition and molded article according to the present invention will be described in detail below. The present invention is not limited to the embodiments shown below. In addition, in this specification, the notation "~" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit, unless otherwise specified.

[0026] The polycarbonate resin composition according to the embodiment of the present invention contains 0.01 to 5 parts by mass of polyether polycarbonate resin (B) per 100 parts by mass of polycarbonate resin (A). In this polycarbonate resin composition, the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8000 to 40000 in terms of polystyrene measured by gel permeation chromatography using chloroform as a solvent. Hereinafter, each component constituting the polycarbonate resin composition according to the embodiment of the present invention and a molded article made of this polycarbonate resin composition will be described in detail.

[0027] [Polyether polycarbonate resin (B)] First, the polyether polycarbonate resin (B), which is one component constituting the polycarbonate resin composition according to the embodiment of the present invention, will be described in detail. The polyether polycarbonate resin (B) used in the present invention is a resin having a polyether and a carbonate bond.

[0028] In detail, the polyether of the polyether polycarbonate resin (B) is, for example, a polyalkylene glycol. This polyalkylene glycol may or may not have a substituent. The polyether polycarbonate resin (B) is composed of such a polyether and a carbonate bond. In the present invention, the polyether polycarbonate resin (B) is preferably a copolymer composed of a polyalkylene glycol bonded via a carbonate bond, that is, a copolymer represented by the following general formula (1).

[0029] [ka]

[0030] In general formula (1), R Z and R X R each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Z and R XThere are multiple R Z and R X may be the same or different. i represents an integer of 2 to 10. p represents an integer of 1 to 600. n represents an integer of 1 to 3000.

[0031] The polyether polycarbonate resin (B) can be produced by a conventional production method such as an interfacial polymerization method or a melt polymerization method. For example, the polyether polycarbonate resin (B) can be produced by a method of reacting a polyalkylene glycol with phosgene, or a method of reacting a polyalkylene glycol with a carbonate precursor such as ethylene carbonate or diphenyl carbonate.

[0032] In the polyether polycarbonate resin (B), various polyalkylene glycols can be used as the polyalkylene glycol that may have a substituent. For example, a preferred example of the polyalkylene glycol is a branched polyalkylene glycol represented by the following general formula (2).

[0033] [ka]

[0034] In the general formula (2), R represents an alkyl group having 1 to 3 carbon atoms. q represents an integer of 2 to 400. The branched polyalkylene glycol represented by the general formula (2) may be a homopolymer having one type of R, or a copolymer having two or more types of R.

[0035] Preferable specific examples of the branched polyalkylene glycol represented by the general formula (2) include polypropylene glycol, polybutylene glycol, etc. The above-mentioned polypropylene glycol is a branched polyalkylene glycol in which R=CH3 (methyl group) in the general formula (2), and i=2, R Z =CH3, R XThe polybutylene glycol is a branched polyalkylene glycol in which R=CH3CH2 (ethyl group) in the general formula (2), and i=2, R Z =CH3CH2,R X = H. Examples of commercially available branched polyalkylene glycols include trade names "UNIOL D-1000" and "UNIOL PB-1000" manufactured by NOF Corporation.

[0036] In the polyether polycarbonate resin (B), the polyalkylene glycol which may have a substituent may be a linear polyalkylene glycol. Examples of the linear polyalkylene glycol include polyethylene glycol (i=2 in the general formula (1), R Z =R X =H), polytrimethylene glycol (i=3 in general formula (1), R Z =R X =H), polytetramethylene glycol (i=4 in general formula (1), R Z =R X =H), polypentamethylene glycol (i=5 in general formula (1), R Z =R X =H), polyhexamethylene glycol (i=6 in general formula (1), R Z =R X Of these, polytrimethylene glycol or polytetramethylene glycol is particularly preferred as the polyalkylene glycol. That is, it is particularly preferred that i in the general formula (1) is 3 or 4. In addition, the substituent of the polyalkylene glycol (R Z , R X ) is preferably a hydrogen atom.

[0037] Commercially available polytrimethylene glycols include those represented by the general formula (1) R Z and R XIn the general formula (1), R is a hydrogen atom. ... Z and R X In the present invention, the polytetramethylene glycol may be commercially available, in which each of the groups is a hydrogen atom. Examples of the commercially available polytetramethylene glycol include "PTMG" manufactured by Mitsubishi Chemical Corporation.

[0038] In the polyether polycarbonate resin (B), the polyalkylene glycol which may have a substituent may be a polyalkylene glycol copolymer having a linear alkylene ether unit represented by the following general formula (3) and a branched alkylene ether unit selected from units represented by any one of the following general formulas (4-1) to (4-4).

[0039] [ka]

[0040] In general formula (3), p represents an integer of 2 to 6. The linear alkylene ether unit represented by general formula (3) may be a single unit having a predetermined integer p, or may be a mixture of multiple units having different integers p.

[0041] [ka]

[0042] In general formulas (4-1) to (4-4), R 1 ~R 10 Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In each of general formulas (4-1) to (4-4), R 1 ~R 10 At least one of them is an alkyl group having 1 to 3 carbon atoms.

[0043] The branched alkylene ether unit of the polyalkylene glycol copolymer may be a homopolymer constituted by a branched alkylene ether unit having a structure represented by any one of general formulas (4-1) to (4-4). Alternatively, the branched alkylene ether unit may be a copolymer constituted by a branched alkylene ether unit having a plurality of structures selected from the structure represented by general formula (4-1), the structure represented by general formula (4-2), the structure represented by general formula (4-3), and the structure represented by general formula (4-4).

[0044] Examples of the linear alkylene ether unit represented by the general formula (3) include ethylene glycol in which p is 2 in the general formula (3), trimethylene glycol in which p is 3 in the general formula (3), tetramethylene glycol in which p is 4 in the general formula (3), pentamethylene glycol in which p is 5 in the general formula (3), and hexamethylene glycol in which p is 6 in the general formula (3). The linear alkylene ether unit may be a mixture of these. Among these, the linear alkylene ether unit is preferably trimethylene glycol or tetramethylene glycol, and more preferably tetramethylene glycol.

[0045] Trimethylene glycol is industrially produced by hydrogenating 3-hydroxypropionaldehyde obtained by hydroformylating ethylene oxide, or by hydrogenating 3-hydroxypropionaldehyde obtained by hydrating acrolein with a Ni catalyst. Recently, trimethylene glycol has also been produced by the biomethod, in which glycerin, glucose, starch, etc. are reduced by microorganisms.

[0046] Examples of the branched alkylene ether unit represented by the general formula (4-1) include glycols such as (2-methyl)ethylene glycol, (2-ethyl)ethylene glycol, and (2,2-dimethyl)ethylene glycol. The branched alkylene ether unit represented by the general formula (4-1) may be a mixture of two or more of these. As the branched alkylene ether unit represented by the general formula (4-1), (2-methyl)ethylene glycol and (2-ethyl)ethylene glycol are preferred.

[0047] Examples of the branched alkylene ether unit represented by the general formula (4-2) include glycols such as (2-methyl)trimethylene glycol, (3-methyl)trimethylene glycol, (2-ethyl)trimethylene glycol, (3-ethyl)triethylene glycol, (2,2-dimethyl)trimethylene glycol, (2,2-methylethyl)trimethylene glycol, (2,2-diethyl)trimethylene glycol (i.e., neopentyl glycol), (3,3-dimethyl)trimethylene glycol, (3,3-methylethyl)trimethylene glycol, (3,3-diethyl)trimethylene glycol, etc. The branched alkylene ether unit represented by the general formula (4-2) may be a mixture of two or more of these.

[0048] Examples of the branched alkylene ether unit represented by the general formula (4-3) include glycols such as (3-methyl)tetramethylene glycol, (4-methyl)tetramethylene glycol, (3-ethyl)tetramethylene glycol, (4-ethyl)tetramethylene glycol, (3,3-dimethyl)tetramethylene glycol, (3,3-methylethyl)tetramethylene glycol, (3,3-diethyl)tetramethylene glycol, (4,4-dimethyl)tetramethylene glycol, (4,4-methylethyl)tetramethylene glycol, and (4,4-diethyl)tetramethylene glycol. The branched alkylene ether unit represented by the general formula (4-3) may be a mixture of two or more of these. Among these, the branched alkylene ether unit represented by the general formula (4-3) is preferably (3-methyl)tetramethylene glycol.

[0049] Examples of the branched alkylene ether unit represented by the general formula (4-4) include glycols such as (3-methyl)pentamethylene glycol, (4-methyl)pentamethylene glycol, (5-methyl)pentamethylene glycol, (3-ethyl)pentamethylene glycol, (4-ethyl)pentamethylene glycol, (5-ethyl)pentamethylene glycol, (3,3-dimethyl)pentamethylene glycol, (3,3-methylethyl)pentamethylene glycol, (3,3-diethyl)pentamethylene glycol, (4,4-dimethyl)pentamethylene glycol, (4,4-methylethyl)pentamethylene glycol, (4,4-diethyl)pentamethylene glycol, (5,5-dimethyl)pentamethylene glycol, (5,5-methylethyl)pentamethylene glycol, and (5,5-diethyl)pentamethylene glycol. The branched alkylene ether unit represented by the general formula (4-4) may be a mixture of two or more of these.

[0050] In the above, the branched alkylene ether units represented by each of the general formulas (4-1) to (4-4) are exemplified as glycols for convenience. However, the branched alkylene ether units are not limited to the above-mentioned glycols and may be alkylene oxides thereof or polyether-forming derivatives thereof.

[0051] The polyalkylene glycol copolymer constituting the polyether polycarbonate resin (B) is preferably a copolymer consisting of a tetramethylene ether unit and a branched alkylene ether unit represented by general formula (4-3), and more preferably a copolymer consisting of a tetramethylene ether unit and a 3-methyltetramethylene ether unit. The polyalkylene glycol copolymer is also preferably a copolymer consisting of a tetramethylene ether unit and a branched alkylene ether unit represented by general formula (4-1), and more preferably a copolymer consisting of a tetramethylene ether unit and a 2-methylethylene ether unit, and a copolymer consisting of a tetramethylene ether unit and a 2-ethylethylene ether unit. The polyalkylene glycol copolymer is also preferably a copolymer consisting of a tetramethylene ether unit and a branched alkylene ether unit represented by general formula (4-2), and more preferably a copolymer consisting of a 2,2-dimethyltrimethylene ether unit, i.e., a neopentyl glycol ether unit.

[0052] The polyalkylene glycol copolymer constituting the polyether polycarbonate resin (B) may be a random copolymer or a block copolymer.

[0053] In the polyalkylene glycol copolymer, the copolymerization ratio of the linear alkylene ether unit represented by the general formula (3) and the branched alkylene ether unit represented by each of the general formulas (4-1) to (4-4) is preferably 95 / 5 to 5 / 95 in terms of the molar ratio (linear alkylene ether unit) / (branched alkylene ether unit). The copolymerization ratio is more preferably 93 / 7 to 40 / 60, and even more preferably 90 / 10 to 65 / 35, and is particularly preferably rich in linear alkylene ether units. The molar fraction is 1 Measurements are performed using a H-NMR measurement device and deuterated chloroform as a solvent.

[0054] Among the above, particularly preferred homopolymers as the polyalkylene glycol constituting the polyether polycarbonate resin (B) are polytrimethylene glycol, poly(2-methyl)ethylene glycol, poly(2-ethyl)ethylene glycol, polytetramethylene glycol, etc. Also, particularly preferred copolymers as the polyalkylene glycol are polytetramethylene glycol-polyethylene glycol, polytetramethylene glycol-polytrimethylene glycol, polytetramethylene glycol-poly(2-methyl)ethylene glycol, polytetramethylene glycol-poly(3-methyl)tetramethylene glycol, polytetramethylene glycol-poly(2-ethyl)ethylene glycol, polytetramethylene glycol-polyneopentyl glycol, polyethylene glycol-polytrimethylene glycol, polyethylene glycol-poly(2-methyl)ethylene glycol, etc.

[0055] The polyalkylene glycol constituting the polyether polycarbonate resin (B) may contain a structure derived from a polyol such as 1,4-butanediol, glycerol, sorbitol, benzenediol, bisphenol A, hydrogenated bisphenol A, cyclohexanediol, or spiroglycol. By adding these polyols during polymerization of the polyalkylene glycol, these organic groups can be imparted to the main chain. Among them, glycerol, sorbitol, bisphenol A, and the like are particularly preferred.

[0056] Examples of polyalkylene glycols containing an organic group in the structure include polyethylene glycol glyceryl ether, poly(2-methyl)ethylene glycol glyceryl ether, poly(2-ethyl)ethylene glycol glyceryl ether, polytetramethylene glycol glyceryl ether, polyethylene glycol-poly(2-methyl)ethylene glycol glyceryl ether, polytetramethylene glycol-poly(2-methyl)ethylene glycol glyceryl ether, polytetramethylene glycol-poly(2-ethyl)polyethylene glycol glyceryl ether, polyethylene glycol sorbityl ether, poly(2-methyl)ethylene glycol sorbityl ether, poly(2-ethyl)ethylene glycol sorbityl ether, polytetramethylene glycol sorbityl ether, polyethylene glycol-poly(2-methyl)ethylene glycol sorbityl ether, Preferred examples thereof include butyl ether, polytetramethylene glycol-poly(2-methyl)ethylene glycol sorbityl ether, polytetramethylene glycol-poly(2-ethyl)ethylene glycol sorbityl ether, bisphenol A-bis(polyethylene glycol) ether, bisphenol A-bis(poly(2-methyl)ethylene glycol) ether, bisphenol A-bis(poly(2-ethyl)ethylene glycol) ether, bisphenol A-bis(polytetramethylene glycol) ether, bisphenol A-bis(polyethylene glycol-poly(2-methyl)ethylene glycol) ether, bisphenol A-bis(polytetramethylene glycol-poly(2-methyl)ethylene glycol) ether, and bisphenol A-bis(polytetramethylene glycol-poly(2-ethyl)polyethylene glycol) ether.

[0057] The weight average molecular weight (Mw) of the polyether (e.g., polyalkylene glycol) constituting the polyether polycarbonate resin (B) is preferably 600 to 8000. The lower limit of the weight average molecular weight (Mw) of the polyalkylene glycol is more preferably 800 or more, and even more preferably 1000 or more. The upper limit of the weight average molecular weight (Mw) of the polyalkylene glycol is more preferably 6000 or less, even more preferably 5000 or less, and particularly preferably 4000 or less. When the weight average molecular weight (Mw) of the polyalkylene glycol exceeds 8000, the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) tends to decrease. When the weight average molecular weight (Mw) of the polyalkylene glycol is less than 600, the impact resistance of the polycarbonate resin composition containing the polyether polycarbonate resin (B) decreases.

[0058] In the present invention, the weight average molecular weight (Mw) is a molecular weight measured in terms of polystyrene by gel permeation chromatography (GPC) using chloroform as a solvent (developing solvent). Specifically, GPC is performed using a high-speed GPC device "HLC-8320" manufactured by Tosoh Corporation, three Tosoh Corporation HZ-M (4.6 mm x 150 mm) columns in series, chloroform as the eluent, and a measurement temperature of 25°C. The polystyrene-equivalent molecular weight value thus obtained is the weight average molecular weight (Mw) in the present invention.

[0059] Among the monomers serving as raw materials for the polyether polycarbonate resin (B), examples of carbonate precursors include carbonyl halides, carbonate esters, etc. As raw materials for the polyether polycarbonate resin (B), one type of carbonate precursor may be used, or two or more types of carbonate precursors may be used in any combination and ratio.

[0060] Among the above carbonate precursors, examples of the carbonyl halide include haloformates such as bischloroformates obtained by the reaction of phosgene with a dihydroxy compound, and monochloroformates of dihydroxy compounds.

[0061] Examples of carbonate esters include diaryl carbonates, dialkyl carbonates, and carbonates of dihydroxy compounds. Examples of diaryl carbonates include diphenyl carbonate and ditolyl carbonate. Examples of dialkyl carbonates include dimethyl carbonate and diethyl carbonate. Examples of carbonates of dihydroxy compounds include biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and cyclic carbonates.

[0062] The method for producing the polyether polycarbonate resin (B) is not particularly limited, and any known method can be adopted. For example, examples of the method for producing the polyether polycarbonate resin (B) 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, the melt transesterification method and the interfacial polymerization method are preferred, and the melt transesterification method is more preferred. In addition, the type of polyalkylene glycol itself that is the raw material for the polyether polycarbonate resin (B) may be one type or two or more types. In addition, the polyalkylene glycol that is the raw material for the polyether polycarbonate resin (B) may contain a plurality of homopolymers, may contain a plurality of copolymers, or may be a mixture of these homopolymers and copolymers. For example, the polyalkylene glycol may contain a plurality of the branched polyalkylene glycols, or may contain a plurality of the linear polyalkylene glycols, or may contain a mixture of the branched polyalkylene glycols and the linear polyalkylene glycols.

[0063] The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8000 to 40000. The lower limit of the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is preferably 10000 or more, and particularly preferably 12000 or more. The upper limit of the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is preferably 37000 or less, more preferably 35000 or less, particularly preferably 30000 or less, and most preferably 25000 or less. When the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) exceeds 40000, the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) tends to decrease. If the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is less than 8,000, gas tends to be generated easily from the polycarbonate resin composition (i.e., the amount of gas generated tends to increase) during molding of a molded article made of the polycarbonate resin composition.

[0064] The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) can be adjusted by selecting the Mw of the polyalkylene glycol, which is one of the comonomer diol raw materials, adjusting the ratio of the carbonate precursor, adding a terminator, adjusting the temperature and pressure during polymerization, etc. For example, in the melt transesterification method, the Mw of the polyether polycarbonate resin (B) can be increased by adjusting the monomer raw material ratio so that the reaction ratio between the carbonate precursor monomer diphenyl carbonate and the diol monomer is close to 1, keeping the polymerization temperature high so that by-product phenol can be easily removed from the polymerization system, keeping the pressure as low as possible, and actively renewing the interface by stirring.

[0065] The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) can be measured by the same method as that of the weight average molecular weight (Mw) of the polyether described above. Specifically, a high-speed GPC device "HLC-8320" manufactured by Tosoh Corporation is used, three columns (4.6 mm x 150 mm) manufactured by Tosoh Corporation are arranged in series, the eluent is chloroform, and the measurement temperature is 25°C. The polystyrene-equivalent molecular weight value obtained by this is the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) in this embodiment.

[0066] In the polycarbonate resin composition according to the embodiment of the present invention, the content of the polyether polycarbonate resin (B) is 0.01 to 5 parts by mass relative to 100 parts by mass of the polycarbonate resin (A). The lower limit of the content of the polyether polycarbonate resin (B) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the polycarbonate resin (A). The upper limit of the content of the polyether polycarbonate resin (B) is preferably 4 parts by mass or less, more preferably 3 parts by mass or less, and particularly preferably 2 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin (A). When the content of the polyether polycarbonate resin (B) is less than 0.01 parts by mass, the effect of improving the hue and heat discoloration resistance of the polycarbonate resin composition cannot be obtained. If the content of the polyether polycarbonate resin (B) exceeds 5 parts by mass, the polycarbonate resin composition becomes cloudy and loses transparency.

[0067] [Polycarbonate resin (A)] Next, the polycarbonate resin (A), which is one component constituting the polycarbonate resin composition according to the embodiment of the present invention, will be described in detail. The polycarbonate resin (A) used in the present invention is not particularly limited as long as it is other than the above-mentioned polyether polycarbonate resin (B), and various types of polycarbonate resins can be used.

[0068] In detail, 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 are aliphatic carbons, and the polycarbonate resin (A) of the present invention may be any of these resins. Among them, the polycarbonate resin (A) is preferably an aromatic polycarbonate resin from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

[0069] Among the monomers that serve as raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include dihydroxybenzenes, dihydroxybiphenyls, dihydroxynaphthalenes, dihydroxydiaryl ethers, bis(hydroxyaryl)alkanes, bis(hydroxyaryl)cycloalkanes, cardo structure-containing bisphenols, dihydroxydiaryl sulfides, dihydroxydiaryl sulfoxides, and dihydroxydiaryl sulfones.

[0070] Examples of dihydroxybenzenes include 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), 1,4-dihydroxybenzene, etc. Examples of dihydroxybiphenyls include 2,5-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 4,4′-dihydroxybiphenyl, etc.

[0071] Examples of dihydroxynaphthalenes include 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.

[0072] Examples of dihydroxydiaryl ethers include 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.

[0073] Examples of bis(hydroxyaryl)alkanes include 2,2-bis(4-hydroxyphenyl)propane (i.e., 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 ethane, 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) 1,1-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, and the like.

[0074] Examples of bis(hydroxyaryl)cycloalkanes include 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-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane. Examples of such cyclohexane include 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, and 1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane.

[0075] Examples of the cardo structure-containing bisphenols include 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, and the like.

[0076] Examples of dihydroxydiaryl sulfides include 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, and the like.

[0077] Examples of dihydroxydiaryl sulfoxides include 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, and the like.

[0078] Examples of dihydroxydiarylsulfones include 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone, and the like.

[0079] Among these, bis(hydroxyaryl)alkanes are preferred. Among bis(hydroxyaryl)alkanes, bis(4-hydroxyphenyl)alkanes are preferred, and in particular, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A) is preferred from the viewpoint of heat resistance.

[0080] As the raw material for the aromatic polycarbonate resin, for example, one type of aromatic dihydroxy compound may be used, or two or more types of aromatic dihydroxy compounds may be used in any combination and ratio.

[0081] Among the monomers serving as raw materials for the polycarbonate resin (A), examples of carbonate precursors include carbonyl halides, carbonate esters, etc. As raw materials for the polycarbonate resin (A), one type of carbonate precursor may be used, or two or more types of carbonate precursors may be used in any combination and ratio.

[0082] Among the above carbonate precursors, examples of the carbonyl halide include haloformates such as bischloroformates obtained by the reaction of phosgene with a dihydroxy compound, and monochloroformates of dihydroxy compounds.

[0083] Examples of carbonate esters include diaryl carbonates, dialkyl carbonates, and carbonates of dihydroxy compounds. Examples of diaryl carbonates include diphenyl carbonate and ditolyl carbonate. Examples of dialkyl carbonates include dimethyl carbonate and diethyl carbonate. Examples of carbonates of dihydroxy compounds include biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and cyclic carbonates.

[0084] The method for producing the polycarbonate resin (A) is not particularly limited, and any method can be adopted. For example, the method for producing the polycarbonate resin (A) can 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, the interfacial polymerization method is particularly preferred.

[0085] The molecular weight of the polycarbonate resin (A) is preferably 10,000 to 30,000 in terms of viscosity average molecular weight (Mv) calculated from the solution viscosity measured at a temperature of 25°C using methylene chloride as a solvent. The lower limit of the viscosity average molecular weight (Mv) of this polycarbonate resin (A) is more preferably 10,500 or more, even more preferably 11,000 or more, particularly preferably 11,500 or more, and most preferably 12,000 or more. The upper limit of the viscosity average molecular weight (Mv) of this polycarbonate resin (A) is more preferably 24,000 or less, even more preferably 20,000 or less. By making the viscosity average molecular weight (Mv) of the polycarbonate resin (A) 10,000 or more, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved. By setting the viscosity average molecular weight (Mv) of the polycarbonate resin (A) to 30,000 or less, it is possible to suppress the decrease in the fluidity of the polycarbonate resin composition of the present invention and improve the fluidity of the polycarbonate resin composition (ensuring high fluidity). As a result, the molding processability of the polycarbonate resin composition is improved, and thin-wall molding can be easily performed.

[0086] The polycarbonate resin (A) may be a mixture of two or more polycarbonate resins having different viscosity average molecular weights. In this case, as long as the viscosity average molecular weight of the polycarbonate resin (A) is within the range of 10,000 to 30,000, the polycarbonate resin (A) may contain a polycarbonate resin having a viscosity average molecular weight outside the range of 10,000 to 30,000.

[0087] In the present invention, the viscosity average molecular weight (Mv) is calculated by measuring the intrinsic viscosity [η] (unit: dl / g) at a temperature of 25° C. using methylene chloride as a solvent and an Ubbelohde viscometer, and calculating the viscosity average molecular weight (Mv) from 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.

[0088]

number

[0089] The terminal hydroxyl group concentration of the polycarbonate resin (A) is arbitrary and may be appropriately selected and determined. For example, the terminal hydroxyl group concentration of the polycarbonate resin (A) is 1000 ppm or less, preferably 800 ppm or less, and more preferably 600 ppm or less. By setting the upper limit of the terminal hydroxyl group concentration in this way, the residence heat stability and color tone of the polycarbonate resin (A) can be further improved. In addition, the lower limit of the terminal hydroxyl group concentration of the polycarbonate resin (A) is 10 ppm or more, preferably 30 ppm or more, and more preferably 40 ppm or more, particularly when the polycarbonate resin (A) is produced by a melt transesterification method. By setting the lower limit of the terminal hydroxyl group concentration in this way, the molecular weight of the polycarbonate resin (A) can be suppressed from decreasing, and the mechanical properties of the polycarbonate resin composition containing the polycarbonate resin (A) can be further improved.

[0090] The unit of the terminal hydroxyl group concentration of the polycarbonate resin (A) is the mass of the terminal hydroxyl group relative to the mass of the polycarbonate resin (A) expressed in ppm. The method for measuring the terminal hydroxyl group concentration is colorimetric determination by the titanium tetrachloride / acetic acid method (the method described in Macromol. Chem. 88 215 (1965)).

[0091] In order to improve the appearance of a molded article made of the polycarbonate resin composition of the present invention and to improve the flowability of the polycarbonate resin composition, the polycarbonate resin (A) may contain a polycarbonate oligomer. The viscosity average molecular weight (Mv) of the polycarbonate oligomer is, for example, 1500 or more, and preferably 2000 or more. The upper limit of the viscosity average molecular weight (Mv) of the polycarbonate oligomer is, for example, 9500 or less, and preferably 9000 or less. Furthermore, the content of the polycarbonate oligomer is preferably 30 mass% or less of the polycarbonate resin (A) containing the polycarbonate oligomer.

[0092] Furthermore, the polycarbonate resin (A) may contain not only virgin raw materials but also polycarbonate resins recycled from used products (so-called material recycled polycarbonate resins) as one raw material component. However, the content of the recycled polycarbonate resin is preferably 80 mass% or less, particularly preferably 50 mass% or less, of the polycarbonate resin (A). This is because the recycled polycarbonate resin is highly likely to have been deteriorated by heat degradation, aging degradation, etc., and if the content of such recycled polycarbonate resin is more than 80 mass%, the color and mechanical properties of the polycarbonate resin composition containing the polycarbonate resin (A) may be deteriorated.

[0093] [Phosphorus-based stabilizer (C)] Next, the phosphorus-based stabilizer (C) applied to the polycarbonate resin composition according to the embodiment of the present invention will be described in detail. The polycarbonate resin composition may further contain the phosphorus-based stabilizer (C) in addition to the above-mentioned polycarbonate resin (A) and polyether polycarbonate resin (B). By containing this phosphorus-based stabilizer (C), the polycarbonate resin composition has a better hue and has better heat discoloration resistance.

[0094] Any known phosphorus-based stabilizer (C) can be used. For example, phosphorus-based stabilizers (C) include phosphorus oxoacids, acid pyrophosphate metal salts, phosphate salts of Group 1 or Group 2B metals, phosphate compounds, phosphite compounds, phosphonite compounds, etc. Among these, phosphite compounds are particularly preferred as phosphorus-based stabilizers (C). By selecting a phosphite compound as the phosphorus-based stabilizer (C), a polycarbonate resin composition having higher heat discoloration resistance and continuous productivity can be obtained.

[0095] Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, polyphosphoric acid, etc. Examples of metal acid pyrophosphates include sodium acid pyrophosphate, potassium acid pyrophosphate, calcium acid pyrophosphate, etc. Examples of phosphates of Group 1 or Group 2B metals include potassium phosphate, sodium phosphate, cesium phosphate, zinc phosphate, etc.

[0096] Here, the phosphite compound is a trivalent phosphorus compound represented by the general formula: P(OR)3. In this general formula, 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, monooctyl diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, bis(2,4- di-tert-butyl-4-methylphenyl)pentaerythritol phosphite, bis(2,6-di-tert-butylphenyl)octyl phosphite, 2,2-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.

[0097] Among the above-mentioned phosphite compounds, the aromatic phosphite compounds represented by the following general formula (5) or general formula (6) are more preferred because they are particularly effective in improving the heat discoloration resistance of the polycarbonate resin composition of the present invention.

[0098] [ka]

[0099] In general formula (5), R 1 , R 2 and R 3 may be the same or different and represent an aryl group having 6 to 30 carbon atoms.

[0100] [ka]

[0101] In general formula (6), R 4 and R 5 may be the same or different and represent an aryl group having 6 to 30 carbon atoms.

[0102] As the aromatic phosphite compound represented by the above general formula (5), for example, triphenyl phosphite, tris(mononylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, etc. are preferable, among these, tris(2,4-di-tert-butylphenyl) phosphite is more preferable. Specific examples of such aromatic 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, "JP-650" manufactured by Johoku Chemical Industry Co., Ltd., etc.

[0103] As the aromatic phosphite compound represented by the above general formula (6), for example, 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, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, etc. are particularly preferred. Preferable specific examples of such aromatic phosphite compounds include "ADEKA STAB PEP-24G" and "ADEKA STAB PEP-36" manufactured by ADEKA Corporation, and "Doverphos S-9228" manufactured by Doverchemical Co., Ltd.

[0104] Among the above-mentioned phosphite compounds, the aromatic phosphite compound represented by the general formula (6) is particularly preferred as the phosphorus-based stabilizer (C), because the inclusion of the aromatic phosphite compound leads to a more excellent color of the polycarbonate resin composition of the present invention.

[0105] The polycarbonate resin composition of the present invention may contain one type of phosphorus-based stabilizer (C), or may contain two or more types of phosphorus-based stabilizers (C) in any combination and ratio.

[0106] When the polycarbonate resin composition of the present invention contains a phosphorus-based stabilizer (C), the content of the phosphorus-based stabilizer (C) is 0.005 to 0.5 parts by mass relative to 100 parts by mass of the polycarbonate resin (A) in the polycarbonate resin composition. The lower limit of the content of the phosphorus-based stabilizer (C) is preferably 0.007 parts by mass or more, more preferably 0.008 parts by mass or more, and particularly preferably 0.01 parts by mass or more. The upper limit of the content of the phosphorus-based stabilizer (C) is preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, even more preferably 0.2 parts by mass or less, and particularly preferably 0.1 parts by mass or less.

[0107] If the content of the phosphorus-based stabilizer (C) is less than 0.005 parts by mass, the effect of improving the color and heat discoloration resistance of the polycarbonate resin composition due to the inclusion of the phosphorus-based stabilizer (C) may not be obtained. If the content of the phosphorus-based stabilizer (C) exceeds 0.5 parts by mass, the heat discoloration resistance of the polycarbonate resin composition may worsen. Furthermore, the humidity heat stability of the polycarbonate resin composition may be reduced.

[0108] [Epoxy compound (D)] Next, the epoxy compound (D) applied to the polycarbonate resin composition according to the embodiment of the present invention will be described in detail. The polycarbonate resin composition may further contain the epoxy compound (D) in addition to the above-mentioned polycarbonate resin (A) and polyether polycarbonate resin (B). By containing this epoxy compound (D) together with the polyether polycarbonate resin (B), the heat discoloration resistance of the polycarbonate resin composition can be further improved.

[0109] As the epoxy compound (D), for example, a compound having one or more epoxy groups in one molecule is used. Preferable specific examples of such epoxy compound (D) include 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-methyl ... -methylcyclohexyl)butyl-3',4'-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethylene 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-epoxy Dicyclopentadienyl ether, bis-epoxy ethylene glycol, bis-epoxy cyclohexyl 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 carboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate, N-butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexyl carboxylate, octadecyl-3,4-epoxycyclohexyl carboxylate, 2-ethylhexyl-3',4'-epoxycyclohexyl carboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3',4'-epoxycyclohexyl carboxylate, 4,Examples of the epoxy tetrahydrophthalic anhydride include 5-epoxy tetrahydrophthalic anhydride, 3-t-butyl-4,5-epoxy tetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, di-n-butyl-3-t-butyl-4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, epoxidized soybean oil, and epoxidized linseed oil.

[0110] Among these epoxy compounds (D), alicyclic epoxy compounds are preferably used, and 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate is particularly preferred.

[0111] As the epoxy compound (D), a polyalkylene glycol derivative having an epoxy group at one or both ends can also be preferably used, and in particular, a polyalkylene glycol having an epoxy group at both ends is preferred.

[0112] Preferred specific examples of the polyalkylene glycol derivatives include polyalkylene glycol derivatives containing an epoxy group in the structure, such as polyethylene glycol diglycidyl ether, poly(2-methyl)ethylene glycol diglycidyl ether, poly(2-ethyl)ethylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, polyethylene glycol-poly(2-methyl)ethylene glycol diglycidyl ether, polytetramethylene glycol-poly(2-methyl)ethylene glycol diglycidyl ether, and polytetramethylene glycol-poly(2-ethyl)ethylene glycol diglycidyl ether.

[0113] The polycarbonate resin composition of the present invention may contain one type of epoxy compound (D), or may contain two or more types of epoxy compounds (D) in any combination and ratio.

[0114] When the polycarbonate resin composition of the present invention contains an epoxy compound (D), the preferred content of the epoxy compound (D) is 0.0005 to 0.2 parts by mass relative to 100 parts by mass of the polycarbonate resin (A). The lower limit of the content of the epoxy compound (D) is preferably 0.001 parts by mass or more, more preferably 0.003 parts by mass or more, and particularly preferably 0.005 parts by mass or more. The upper limit of the content of the epoxy compound (D) is preferably 0.15 parts by mass or less, more preferably 0.1 parts by mass or less, and particularly preferably 0.05 parts by mass or less.

[0115] If the content of the epoxy compound (D) is less than 0.0005 parts by mass, the effect of improving the color and heat discoloration resistance of the polycarbonate resin composition due to the inclusion of the epoxy compound (D) may not be obtained. If the content of the epoxy compound (D) is more than 0.2 parts by mass, the heat discoloration resistance of the polycarbonate resin composition may worsen. Furthermore, the color and wet heat stability of the polycarbonate resin composition may be reduced.

[0116] [Oxetane Compound (E)] Next, the oxetane compound (E) applied to the polycarbonate resin composition according to the embodiment of the present invention will be described in detail. The polycarbonate resin composition may further contain an oxetane compound (E) in addition to the above-mentioned polycarbonate resin (A) and polyether polycarbonate resin (B). By containing this oxetane compound (E) together with the polyether polycarbonate resin (B), the heat discoloration resistance of the polycarbonate resin composition can be further improved.

[0117] As the oxetane compound (E), for example, any compound having one or more oxetane groups in the molecule can be used. That is, both monooxetane compounds having one oxetane group in the molecule and polyoxetane compounds having two or more functional groups in the molecule can be used as the oxetane compound (E). By containing the oxetane compound (E), the color of the polycarbonate resin composition of the present invention can be made better and the heat discoloration resistance can be further improved.

[0118] Preferable specific examples of the monooxetane compound include a compound represented by the following general formula (III-a), a compound represented by the general formula (III-b), or a compound represented by the general formula (IV).

[0119] [ka]

[0120] [ka]

[0121] In the general formula (III-a), the general formula (III-b) and the general formula (IV), R 1 R in the general formula (III-b) represents an alkyl group. 2 R in the general formula (IV) represents an alkyl group or a phenyl group. 3 represents a divalent organic group. 3 The divalent organic group represented by the following formula (IV) may or may not have an aromatic ring. In general formula (IV), n is 0 or 1.

[0122] In addition, in the general formula (III-a), the general formula (III-b) and the general formula (IV), R 1 is an alkyl group as described above, 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.

[0123] In addition, in the general formula (III-b), R 2 As described above, R is an alkyl group or a phenyl group, but is preferably an alkyl group having 2 to 10 carbon atoms. The alkyl group having 2 to 10 carbon atoms may be any of a linear alkyl group, a branched alkyl group, and an alicyclic alkyl group, and 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.

[0124] Preferred specific examples of the compound represented by general formula (III-a) include 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxymethyl-3-normal butyloxetane, and 3-hydroxymethyl-3-propyloxetane. Among these, 3-hydroxymethyl-3-methyloxetane and 3-hydroxymethyl-3-ethyloxetane are particularly preferred. Also, preferred specific examples of the compound represented by general formula (III-b) include 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane.

[0125] In the general formula (IV), R 3 As described above, R is a divalent organic group that may or may not have an aromatic ring. 3Specific examples of the alkylene group 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; a divalent group represented by the formula -CH2-Ph-CH2- or -CH2-Ph-Ph-CH2- (wherein 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.

[0126] Particularly preferred specific examples of the compound represented by general formula (IV) 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.

[0127] The polycarbonate resin composition of the present invention may contain one type of oxetane compound (E), or may contain two or more types of oxetane compounds (E) in any combination and ratio.

[0128] When the polycarbonate resin composition of the present invention contains an oxetane compound (E), the content of the oxetane compound (E) is preferably 0.0005 to 0.2 parts by mass relative to 100 parts by mass of the polycarbonate resin (A). The lower limit of the content of the oxetane compound (E) is more preferably 0.001 parts by mass or more, even more preferably 0.003 parts by mass or more, and particularly preferably 0.005 parts by mass or more. The upper limit of the content of the oxetane compound (E) is more preferably 0.15 parts by mass or less, even more preferably 0.1 parts by mass or less, and particularly preferably 0.05 parts by mass or less.

[0129] If the content of the oxetane compound (E) is less than 0.0005 parts by mass, the effect of improving the color and heat discoloration resistance of the polycarbonate resin composition due to the inclusion of the oxetane compound (E) may not be obtained. If the content of the oxetane compound (E) exceeds 0.2 parts by mass, the heat discoloration resistance of the polycarbonate resin composition may worsen. Furthermore, gas may be easily generated during molding of the polycarbonate resin composition.

[0130] The polycarbonate resin composition of the present invention preferably contains both the epoxy compound (D) and the oxetane compound (E) described above. In this case, the total content of the epoxy compound (D) and the oxetane compound (E) is preferably 0.0005 to 0.2 parts by mass per 100 parts by mass of the polycarbonate resin (A).

[0131] [Additives, etc.] Next, additives and the like applied to the polycarbonate resin composition according to the embodiment of the present invention will be described in detail. The polycarbonate resin composition may contain other additives in addition to the above-mentioned components such as the polycarbonate resin (A) and the polyether polycarbonate resin (B). Examples of the additives include antioxidants, release agents, ultraviolet absorbers, fluorescent whitening agents, pigments, dyes, polymers other than polycarbonate resins, flame retardants, impact resistance improvers, antistatic agents, plasticizers, and compatibilizers. Examples of the polymers other than the polycarbonate resins include polyalkylene glycols. The polyalkylene glycols that may be contained in the polycarbonate resin composition have the same structure as the polyalkylene glycols constituting the above-mentioned polyether polycarbonate resin (B). The polycarbonate resin composition may contain one type of additive among these additives, or may contain an additive in which two or more types are blended.

[0132] However, when the polycarbonate resin composition of the present invention contains a polymer other than the polycarbonate resin (A) and the polyether polycarbonate resin (B), the content of the other polymer 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 total of the polycarbonate resin (A) and the polyether polycarbonate resin (B).

[0133] [Yellowing index and yellowing index of polycarbonate resin composition] Next, the yellowness and yellowing index of the polycarbonate resin composition according to the embodiment of the present invention will be described. The yellowness index (YI) is an index representing the degree of the hue of the polycarbonate resin composition. For example, the hue of the polycarbonate resin composition is represented by the initial value of the yellowness index (hereinafter referred to as the initial YI value). The initial YI value is the YI value of the polycarbonate resin composition in the initial state before deterioration due to a load such as heat or deterioration over time occurs. The yellowing index ΔYI is an index representing the heat discoloration resistance of the polycarbonate resin composition. The yellowing index ΔYI is represented by the difference between the YI value of the polycarbonate resin composition after being held under a predetermined temperature and time condition and the initial YI value.

[0134] The initial YI value and the yellowing index ΔYI are each set to a value equal to or less than a preset threshold value. For example, when light from a light source passes through a 300 mm optical path in a polycarbonate resin composition, the threshold value of the initial YI value is set to 25.0, and the threshold value of the yellowing index ΔYI is set to 6.5. The initial YI value of the polycarbonate resin composition of the present invention at an optical path length of 300 mm is preferably 25.0 or less. Furthermore, the difference between the YI value of the polycarbonate resin composition at an optical path length of 300 mm after a predetermined accelerated aging test and the initial YI value, i.e., the yellowing index ΔYI, is preferably 6.5 or less. As the accelerated aging test, for example, a test in which the polycarbonate resin composition is held at a temperature of 95° C. for 1000 hours can be mentioned.

[0135] When the initial YI value exceeds 25.0, the light (transmitted light) after passing through a 300 mm optical path in the polycarbonate resin composition in the initial state is yellowed to an extent that exceeds the allowable hue change for the polycarbonate resin composition (for example, to an extent that can be confirmed by visual inspection) compared to the light emitted from the light source. Also, when the yellowing index ΔYI exceeds 6.5, the light that has passed through a 300 mm optical path in the polycarbonate resin composition after the accelerated aging test is yellowed to an extent that exceeds the allowable hue change for the polycarbonate resin composition compared to the transmitted light having the hue represented by the initial YI value.

[0136] [Method for producing polycarbonate resin composition] Next, the method for producing the polycarbonate resin composition according to the embodiment of the present invention will be described in detail. The method for producing the polycarbonate resin composition is not particularly limited, and known methods for producing polycarbonate resin compositions can be widely adopted. In one example of the production method, the polycarbonate resin (A) and the polyether polycarbonate resin (B) are mixed in advance using various mixers such as a tumbler or a Henschel mixer with other components that are mixed as necessary. Examples of the other components include the phosphorus-based stabilizer (C), the epoxy compound (D), the oxetane compound (E), and additives. After mixing the components in this way, the resulting mixture is melt-kneaded with a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, or a kneader to obtain the polycarbonate resin composition of the present invention. The temperature of the melt-kneading of the mixture is not particularly limited, but is, for example, within the range of 240 to 320°C.

[0137] [Molded products] Next, a molded article of the polycarbonate resin composition according to the embodiment of the present invention will be described in detail. The molded article of the present invention is a molded article made of the polycarbonate resin composition according to the embodiment described above, and can be produced, for example, by pelletizing the polycarbonate resin composition and molding the pellets obtained by various molding methods. The molded article of the present invention may also be produced by directly molding the polycarbonate resin composition melt-kneaded in an extruder, without going through the above-mentioned pellets.

[0138] The molded article produced by the above molding method is made of the polycarbonate resin composition of the present invention, and therefore has a good hue, excellent heat discoloration resistance, and excellent transparency. Examples of such molded articles include optical parts such as light guide plates. The hue and heat discoloration resistance of the molded article are expressed by the initial YI value and the yellowing index ΔYI, respectively, as in the case of the above-mentioned polycarbonate resin composition. That is, the initial YI value of the molded article at an optical path length of 300 mm is preferably 25.0 or less, and the yellowing index ΔYI of the molded article at an optical path length of 300 mm is preferably 6.5 or less.

[0139] As described above, the polycarbonate resin composition of the present invention has high fluidity and good color, is excellent in transparency, and can greatly reduce mold contamination caused by gas generation during molding. Therefore, molded products such as optical parts that enjoy the effects of the polycarbonate resin composition can be easily obtained by a desired molding method such as injection molding. In particular, the polycarbonate resin composition of the present invention is suitable for molding thin-walled and large optical parts that are prone to mold contamination.

[0140] In addition, the resin temperature during injection molding is preferably higher than 260 to 300°C, which is the temperature generally applied to injection molding of polycarbonate resin, particularly when producing a large thin-walled molded product, and is preferably, for example, 305 to 400°C. The lower limit of this resin temperature is more preferably 310°C or higher, even more preferably 315°C or higher, and particularly preferably 320°C or higher. The upper limit of this resin temperature is more preferably 390°C or lower. When a conventional polycarbonate resin composition is used, there is a problem that if the resin temperature during molding is increased to mold a large thin-walled molded product, the molded product obtained is likely to turn yellow. In contrast, by using the polycarbonate resin composition of the present invention, it is possible to produce molded products, particularly large and thin-walled optical parts, having good hue and excellent transparency even in the above temperature range. In addition, when it is difficult to directly measure the resin temperature, the barrel setting temperature during molding is used as the resin temperature.

[0141] Here, a large thin-walled molded product refers to a molded product having a plate-shaped part with a wall thickness of 1 mm or less, preferably 0.8 mm or less, more preferably 0.6 mm or less, and a dimension such as a vertical or horizontal length or a diameter corresponding to the optical path length of 100 mm or more. The plate-shaped part may be flat or curved. The surface of the plate-shaped part may be a flat surface or a surface having projections and recesses. The cross section of the plate-shaped part may have an inclined surface or may be a wedge-shaped cross section.

[0142] The optical components of the present invention include components of devices and instruments that directly or indirectly use light sources such as LEDs (Light Emitting Diodes), organic EL (Electro Luminescence), incandescent bulbs, fluorescent lamps, and cathode tubes. Representative examples of such optical components include light guide plates and members for surface light emitters. Light guide plates are used to guide light from light sources such as LEDs in liquid crystal backlight units and various display devices and lighting devices. For example, light guide plates usually diffuse light received from the side or back side, etc., by unevenness provided on the surface, and emit uniform light. In general, the shape of the light guide plate is a flat plate. The surface of the light guide plate may or may not have unevenness. In addition, the light guide plate is preferably molded by a molding method such as injection molding, ultra-high speed injection molding, injection compression molding, and melt extrusion molding (for example, T-die molding).

[0143] A light guide plate molded using the polycarbonate resin composition of the present invention has no cloudiness or decrease in transmittance, has good hue and excellent transparency, and is less prone to molding defects due to mold contamination.

[0144] 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 devices to which such light guide plates are applied include various mobile terminals such as mobile phones, mobile notebooks, netbooks, slate PCs (personal computers), tablet PCs, smartphones, and tablet terminals, cameras, watches, desktop or laptop (notebook) PCs, various displays, and lighting equipment.

[0145] The optical components molded from the polycarbonate resin composition of the present invention may be in the form of a film or sheet, and specific examples of such optical components include light-guiding films.

[0146] Furthermore, the optical component of the present invention can be suitably used not only as a light guide plate for the above-mentioned applications, but also as a light guide or lens that guides light from a light source such as an LED in vehicle lighting devices such as headlamps, rear lamps, or fog lamps of automobiles or motorcycles. EXAMPLES

[0147] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples.

[0148] [Production Example 1 of Polyether Polycarbonate Resin (B)] In Production Example 1, a production example of a polytetramethylene glycol-polycarbonate copolymer, which is a first example of the polyether polycarbonate resin (B), is shown. Specifically, polytetramethylene glycol and diphenyl carbonate (hereinafter abbreviated as DPC) were first added to a polymerization apparatus equipped with a 1L three-neck flask so that the molar ratio of DPC to polytetramethylene glycol was 1.12. In Production Example 1, the polytetramethylene glycol used was a product name "PTMG650" (Mw: 1700) manufactured by Mitsubishi Chemical Corporation. Then, a Zn(OAc) aqueous solution was added as a catalyst to the polymerization apparatus. At this time, the catalyst was added so that the amount of Zn per mol of polytetramethylene glycol was 10 μmol / diol. Next, the inside of the system was dried for 1 hour, and the inside of the polymerization apparatus was restored to pressure with nitrogen.

[0149] The polymerization apparatus restored to pressure as described above was immersed in an oil bath, and polytetramethylene glycol and DPC in the polymerization apparatus were polymerized. In Production Example 1, the polymerization reaction was started when the polymerization apparatus was immersed in the oil bath. The temperature and pressure in the polymerization apparatus were set according to the temperature increase / reduction program shown in Table 1 below. Specifically, the set temperature in the polymerization apparatus was 200°C at the start of polymerization, and was increased to 217°C 10 minutes after the start of polymerization, and was then maintained at 217°C until 170 minutes had passed from the start of polymerization. The set pressure in the polymerization apparatus was 97 kPaA at the start of polymerization, and was subsequently sequentially reduced, and reduced to 0.13 kPaA or less with a vacuum pump full vacuum (FV) 100 minutes after the start of polymerization. This reduced set pressure was maintained until before 170 minutes had passed from the start of polymerization, and was increased to 100 kPaA after 170 minutes had passed. The polymerization reaction between polytetramethylene glycol and DPC in this polymerization reactor proceeded under these temperature and pressure conditions, and was completed 170 minutes after the start of the polymerization.

[0150] In Production Example 1, a polytetramethylene glycol-polycarbonate copolymer was obtained by the polymerization reaction of the above-mentioned polytetramethylene glycol and DPC. The weight average molecular weight (Mw) of the obtained polytetramethylene glycol-polycarbonate copolymer was 21700. Hereinafter, the polytetramethylene glycol-polycarbonate copolymer produced in Production Example 1 is referred to as polyether polycarbonate resin (B1).

[0151] [Table 1]

[0152] [Production Examples 2 and 3 of Polyether Polycarbonate Resin (B)] Production Examples 2 and 3 are similar to Production Example 1 except that the raw materials for the polymerization reaction are different. The raw materials for the polymerization reaction in Production Examples 1 to 3 and the physical properties of the obtained polyether polycarbonate resins are shown in Table 2. In Production Example 2, a polytrimethylene glycol polycarbonate copolymer (Mw: 16500) was obtained, which is a second example of polyether polycarbonate resin (B). Hereinafter, the polytrimethylene glycol polycarbonate copolymer of Production Example 2 is referred to as polyether polycarbonate resin (B2). In Production Example 3, a polytrimethylene glycol polycarbonate copolymer (Mw: 19900) was obtained, which is a third example of polyether polycarbonate resin (B). Hereinafter, the polytrimethylene glycol polycarbonate copolymer of Production Example 3 is referred to as polyether polycarbonate resin (B3).

[0153] [Table 2]

[0154] (Examples 1 to 18, Comparative Examples 1 to 4) [Components of polycarbonate resin composition] The components of the polycarbonate resin composition in each of Examples 1 to 18 and Comparative Examples 1 to 4 are as shown in Table 3. In each of Examples 1 to 18 and Comparative Examples 1 to 4, the polycarbonate resin (A), polyether polycarbonate resin (B), polyalkylene glycol (X), phosphorus-based stabilizer (C), epoxy compound (D), oxetane compound (E) and release agent (F) shown in Table 3 are used as necessary.

[0155] As the polycarbonate resin (A), polycarbonate resin (A1), polycarbonate resin (A2) or polycarbonate resin (A3) is used. As the polyether polycarbonate resin (B), polyether polycarbonate resin (B1) of Production Example 1, polyether polycarbonate resin (B2) of Production Example 2 or polyether polycarbonate resin (B3) of Production Example 3 is used. As the polyalkylene glycol (X), any of polyalkylene glycols (X1) to (X6) is used. As the phosphorus-based stabilizer (C), phosphorus-based stabilizer (C1), phosphorus-based stabilizer (C2) or phosphorus-based stabilizer (C3) is used. As the epoxy compound (D), epoxy compound (D1) is used, and as the oxetane compound (E), oxetane compound (E1) is used. As the release agent (F), release agent (F1) is used.

[0156] [Table 3]

[0157] [Method for producing pellets of polycarbonate resin composition] In each of Examples 1 to 18 and Comparative Examples 1 to 4, the components shown in Table 3 above were blended in the ratios (parts by mass) shown in Tables 4-1 to 4-3 below and mixed in a tumbler for 20 minutes. Next, using a vented single-screw extruder with a screw diameter of 40 mm (Tanabe Plastic Machinery Co., Ltd.'s "VS-40"), the cylinder temperature was set to 240°C, and the mixture of the components above was melt-kneaded to produce a polycarbonate resin composition. Thereafter, strands of this polycarbonate resin composition were extruded, and the extruded strands were cut (pelletized) to obtain pellets of this polycarbonate resin composition.

[0158] [Strand Transparency Rating] In each of Examples 1 to 18 and Comparative Examples 1 to 4, a strand transparency evaluation was performed on the strand obtained during the production of pellets of the polycarbonate resin composition. In detail, the transparency of the strand extruded from the extruder in the above-mentioned process for producing pellets of the polycarbonate resin composition was visually judged based on the following evaluation criteria. <Evaluation criteria> A: The extruded strands have extremely high transparency, and the compatibility of the polycarbonate resin (A) with the polyether polycarbonate resin (B) and the polyalkylene glycol is extremely good. B: The extruded strands have high transparency and the compatibility of the polycarbonate resin (A) with the polyether polycarbonate resin (B) and the polyalkylene glycol is good. C: The extruded strands were cloudy, and the compatibility of the polycarbonate resin (A) with the polyether polycarbonate resin (B) or with the polyalkylene glycol was poor. D: The extruded strands were significantly cloudy, and the compatibility of the polycarbonate resin (A) with the polyether polycarbonate resin (B) or the polyalkylene glycol was extremely poor.

[0159] [Evaluation of mold contamination during injection molding (evaluation of mold deposits)] In each of Examples 1 to 18 and Comparative Examples 1 to 4, the mold contamination caused by gas generation during injection molding of the polycarbonate resin composition was evaluated. In detail, the pellets obtained by the above-mentioned manufacturing method were dried at 120°C for 5 hours, and then fed to an injection molding machine (Sumitomo Heavy Industries, Ltd. "SE7M"), and 100 shots of injection molding of the polycarbonate resin composition were performed using a teardrop-shaped mold 1 as shown in FIG. 1. The conditions during this injection molding were a cylinder temperature of 340°C, a molding cycle of 10 seconds, and a mold temperature of 40°C. In the mold contamination evaluation, the state of dirt caused by white deposits generated on the metal mirror surface on the mold fixing side of the teardrop-shaped mold 1 after the above-mentioned injection molding was visually judged based on the following evaluation criteria. <Evaluation 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 contamination of the mold due to said adhesion is observed. C: There is a relatively large amount of adhesion to the mold, and the mold is contaminated by the adhesion. D: There is a lot of material adhering to the mold, and the mold is noticeably contaminated by the material.

[0160] As shown in Fig. 1, the teardrop-shaped mold 1 is a mold including a teardrop-shaped mold body and a gate G provided on the side of the mold body opposite to the pointed end P (hereinafter referred to as the base end). The teardrop-shaped mold 1 is designed so that the polycarbonate resin composition is introduced from the gate G and gas generated from the polycarbonate resin composition is easily accumulated inside the pointed end P. The deposits generated on the teardrop-shaped mold 1 originate from the gas generated from the polycarbonate resin composition.

[0161] For example, in the teardrop-shaped mold 1, the width of the gate G is 1 mm, and the thickness of the gate G is 1 mm. As shown in FIG. 1, the width h1 is the maximum width of the teardrop shape of the teardrop-shaped mold 1, and is 14.5 mm. The length h2 is the length between the base end of the teardrop-shaped mold 1 and the part with the maximum width, and is 7 mm. The length h3 is the length between the base end and the tip end P of the teardrop-shaped mold 1, and is 27 mm. The thickness of the molding part (mold body) of the teardrop-shaped mold 1 is 3 mm. Note that the drawings are schematic, and the dimensional relationship of each element shown in the drawings, the ratio of each element, etc. may differ from the actual ones.

[0162] [Evaluation of color and heat discoloration resistance] In each of Examples 1 to 18 and Comparative Examples 1 to 4, the hue and heat discoloration resistance of the optical path made of the polycarbonate resin composition were evaluated. In detail, the pellets obtained by the above manufacturing method were dried at 120°C for 5 to 7 hours by a hot air circulation type dryer, and then fed to an injection molding machine (Sodick's "HSP100A"), and the polycarbonate resin composition was injection molded by this injection molding machine to form a long optical path molded product. The conditions during this injection molding were a resin temperature (cylinder temperature) of 340°C and a mold temperature of 80°C. The obtained long optical path molded product was made of a polycarbonate resin composition and had an optical path length of 300 mm. The size of this long optical path molded product was length x width x thickness = 300 mm x 7 mm x 4 mm.

[0163] In the evaluation of the hue, the initial YI value, which is an index capable of judging the quality of the hue of the polycarbonate resin composition, was measured. Specifically, the initial YI value was measured at an optical path length of 300 mm for the above-mentioned long optical path molded product. The initial YI value can be measured by transmitting light through the optical path (optical path length: 300 mm) of the long optical path molded product, receiving the transmitted light at the light receiving section under the geometric condition e (0°:0°) of light receiving conforming to JIS Z 8722, and measuring the YI calculated conforming to ASTM D 1925. A long optical path spectrophotometer ("ASA 1" manufactured by Nippon Denshoku Industries Co., Ltd., C light source, 2° field of view) was used to measure the initial YI value.

[0164] In the evaluation of heat discoloration resistance, the yellowing index ΔYI, which is an index capable of judging the quality of the heat discoloration resistance of the polycarbonate resin composition, was derived. Specifically, the long optical path molded product for which the initial YI value was measured was kept in a high-temperature environment of 95°C for 1000 hours, and then the YI value of the long optical path molded product at an optical path length of 300 mm was measured, and the yellowing index ΔYI, which is the difference between the obtained YI value and the initial YI value, was obtained. The YI value in the evaluation of heat discoloration resistance can be measured by the same method as the initial YI value described above, except that the measurement object is the long optical path molded product after being kept in a high-temperature environment.

[0165] Tables 4-1 to 4-3 show the content (parts by mass) of each component of the polycarbonate resin composition and the results of each of the above evaluations in each of Examples 1 to 18 and Comparative Examples 1 to 4. In Tables 4-1 to 4-3, "YI (300 mm)" means the initial YI value at an optical path length of 300 mm, and "ΔYI (300 mm)" means the yellowing index ΔYI at an optical path length of 300 mm.

[0166] As shown in Tables 4-1 and 4-2, in Examples 1 to 18, the results of the strand transparency evaluation and the mold contamination evaluation were all "A". That is, in all of Examples 1 to 18, the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) was extremely good, and even when polyalkylene glycol was added, the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) and the polyalkylene glycol was extremely good. Furthermore, in all of Examples 1 to 18, the polycarbonate resin composition generated very little gas during molding, and the mold contamination resistance was extremely good.

[0167] In addition, in Examples 1 to 18, the initial YI value and yellowing index ΔYI of the polycarbonate resin composition at an optical path length of 300 mm were the values ​​shown in Tables 4-1 and 4-2. In detail, in all of Examples 1 to 18, the initial YI value was a value equal to or less than the threshold value (=25.0) of the initial YI value when the target optical path length was 300 mm, and the yellowing index ΔYI was a value equal to or less than the threshold value (=6.5) of the yellowing index ΔYI when the target optical path length was 300 mm. From these results, it was confirmed that the initial hue was good and the heat discoloration resistance was also excellent in all of the polycarbonate resin compositions in Examples 1 to 18.

[0168] On the other hand, as shown in Table 4-3, the results of the strand transparency evaluation were good in Comparative Examples 1 and 4, but were poor in Comparative Examples 2 and 3. In addition, the results of the mold staining evaluation were good in Comparative Example 1, but were poor in Comparative Examples 2 to 4.

[0169] In Comparative Example 1, the results of the strand transparency evaluation and the mold contamination evaluation were good as described above, but the initial YI value at an optical path length of 300 mm exceeded the threshold, and the initial hue was poor. In Comparative Examples 2 and 4, the initial YI value at an optical path length of 300 mm was below the threshold, but the yellowing index ΔYI at an optical path length of 300 mm exceeded the threshold, and the heat discoloration resistance was poor. In Comparative Example 3, the optical path itself made of the polycarbonate resin composition became cloudy, and the initial YI value and the yellowing index ΔYI could not be obtained.

[0170] [Table 4-1]

[0171] [Table 4-2]

[0172] [Table 4-3]

[0173] The present invention is not limited to the above-described embodiment and examples, and includes configurations in which the above-described components are appropriately combined. In addition, other embodiments, examples, and operational techniques made by those skilled in the art based on the above-described embodiment are all included in the scope of the present invention. [Industrial Applicability]

[0174] The polycarbonate resin composition according to the present invention has high fluidity and good hue, and further has excellent transparency, and causes very little mold contamination due to gas generation during molding, and therefore can be extremely suitably used for various molded products, in particular optical parts such as light guide plates. [Explanation of symbols]

[0175] 1 Teardrop mold G Gate P Point

Claims

1. The composition contains 0.01 to 5 parts by mass of a polyether polycarbonate resin (B) having a polyether and a carbonate bond per 100 parts by mass of the polycarbonate resin (A), The polyether polycarbonate resin (B) is a copolymer represented by the following general formula (1): The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8,000 to 40,000 in terms of polystyrene measured by gel permeation chromatography using chloroform as a solvent. A polycarbonate resin composition comprising: 【Chemistry 1】 (In general formula (1), R Z and R X each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. There are a plurality of R Z and R X , and the plurality of R Z and R X may be the same or different. i represents an integer of 2 to 10, p represents an integer of 1 to 600, and n represents an integer of 1 to 3000.)

2. In the general formula (1), i is 3 or 4. The polycarbonate resin composition according to claim 1 .

3. The composition further contains 0.005 to 0.5 parts by mass of a phosphorus-based stabilizer (C) relative to 100 parts by mass of the polycarbonate resin (A). The polycarbonate resin composition according to claim 1 or 2.

4. The weight average molecular weight (Mw) of the polyether constituting the polyether polycarbonate resin (B) is 600 to 8,000 in terms of polystyrene measured by gel permeation chromatography using chloroform as a solvent.

4. The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin composition is a polycarbonate resin composition having a molecular weight of 100 or more.

5. The initial YI value of the polycarbonate resin composition at an optical path length of 300 mm is 25.0 or less, the difference ΔYI between the YI value at an optical path length of 300 mm of the polycarbonate resin composition after being held at 95° C. for 1000 hours and the initial YI value is 6.5 or less; 5. The polycarbonate resin composition according to claim 1,

6. The polycarbonate resin composition according to any one of claims 1 to 5, A molded article characterized by:

7. Optical components, The molded article according to claim 6 .

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