JP2022144176A - Polycarbonate resin composition and molded article - Google Patents

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

The present invention relates to polycarbonate resin compositions and molded articles.

2. Description of the Related Art Liquid crystal display devices used in personal computers, mobile phones, etc. incorporate planar light source devices in order to meet demands for thinness, weight reduction, labor saving, and high definition. For the purpose of uniformly and efficiently guiding incident light to the liquid crystal display side, the planar light source device includes a wedge-shaped cross-sectional light guide plate having a uniformly inclined surface on one side, or a flat plate-shaped light guide plate. A light guide plate is provided. Further, some light guide plates are provided with a light scattering function by forming an uneven pattern on the surface thereof.

Such a light guide plate is obtained by injection molding of a thermoplastic resin, and the uneven pattern is imparted by transferring the uneven portion formed on the surface of the insert mold. Conventionally, light guide plates have been molded from resin materials such as polymethyl methacrylate (PMMA). Due to this, the temperature inside the display device tends to rise. For this reason, the resin material of the light guide plate is being replaced with a more heat-resistant polycarbonate resin material.

In general, polycarbonate resins are excellent in mechanical properties, thermal properties, electrical properties and weather resistance. However, the light transmittance of polycarbonate resin is lower than that of resins such as PMMA that have been used in conventional light guide plates. Therefore, when a surface light source body is constructed from a light guide plate made of polycarbonate resin and a light source, there is a problem that the luminance is low. Recently, there has been a demand to reduce the chromaticity difference between the light entrance portion of the light guide plate and the portion away from the light entrance portion. be.

For example, Patent Document 1 proposes a method for improving light transmittance and brightness by adding an acrylic resin and an alicyclic epoxy compound to a polycarbonate resin. Patent Literature 2 proposes a method for improving brightness by modifying the ends of a polycarbonate resin to improve the transferability of uneven portions to a light guide plate. Patent Document 3 proposes a method of improving the luminance by introducing a copolyestercarbonate having an aliphatic segment to improve the transferability.

However, in the method described in Patent Literature 1, although the addition of the acrylic resin improves the hue, it is difficult to increase the light transmittance and brightness due to the white turbidity. Addition of an alicyclic epoxy compound may improve transmittance, but no effect of improving hue is observed. The methods described in Patent Documents 2 and 3 can be expected to improve the fluidity and transferability of the resin constituting the light guide plate, but have the drawback of lowering the heat resistance.

On the other hand, it is known to blend a compound such as polyethylene glycol or poly(2-methyl)ethylene glycol into thermoplastic resin such as polycarbonate resin. For example, Patent Document 4 describes a γ-ray radiation-resistant polycarbonate resin containing this compound. Patent Document 5 describes a thermoplastic resin composition obtained by blending this compound with a resin such as PMMA and having excellent antistatic properties and surface appearance.

Further, in Patent Document 6, it is proposed to improve transmittance and hue by blending polyalkylene glycol composed of straight-chain alkyl groups into polycarbonate resin. For example, by blending polytetramethylene ether glycol with polycarbonate resin, improvement in transmittance and yellowness (yellow index: YI) is observed.

Furthermore, Patent Document 7 describes a method for producing a polycarbonate copolymer using a diol obtained by diesterifying polyalkylene glycol as a raw material (comonomer). In the polycarbonate copolymer described in Patent Document 7, the diester diol of polyalkylene glycol is unstable, and the hue and resistance to heat discoloration are deteriorated.

JP-A-11-158364 Japanese Patent Application Laid-Open No. 2001-208917 Japanese Patent Application Laid-Open No. 2001-215336 JP-A-1-22959 JP-A-9-227785 Japanese Patent No. 5699188 JP 2006-016497 A

2. Description of the Related Art In recent years, in the field of various information terminals such as smartphones, tablet terminals, and in-vehicle display devices, optical components such as light guide plates are becoming thinner and larger at a remarkable speed. Molding such optical components requires high barrel temperatures and high injection speeds. Along with this, resin compositions used for molding optical parts are required not only to have excellent optical properties such as good hue and transparency, but also to have high fluidity suitable for injection molding. Further, in injection molding at high temperatures, there is a risk that the amount of gas generated from the resin composition will increase. Therefore, there is a further demand for the above resin composition to reduce mold contamination due to gas generation during injection molding at high temperatures.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polycarbonate having high fluidity and good hue, excellent transparency, and very little mold contamination due to gas generation during molding. An object of the present invention is to provide a resin composition and a molded product.

As a result of extensive studies to solve the above problems, the present inventors have found that by blending a polyether polycarbonate resin having a molecular weight within a specific range in a specific ratio with respect to a polycarbonate resin, high fluidity and good The inventors have found that it is possible to obtain a polycarbonate resin composition which has a hue, is excellent in transparency, and causes very little mold contamination due to gas generation during molding, and has completed the present invention.

That is, in order to solve the above-described problems and achieve the object, the polycarbonate resin composition according to the present invention is a polyether polycarbonate resin having a polyether and a carbonate bond, based on 100 parts by mass of the polycarbonate resin (A). 0.01 to 5 parts by mass of (B) is contained, and the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8000 to 40000 in terms of polystyrene by gel permeation chromatography using chloroform as a solvent. It is characterized by

Further, the polycarbonate resin composition according to the present invention is characterized in that, in the above invention, the polyether polycarbonate resin (B) is a copolymer represented by the following general formula (1).

（一般式（１）中、Ｒ_ZおよびＲ_Xは、各々独立に、水素原子または炭素数１～３のアルキル基を示す。Ｒ_ZおよびＲ_Xは各々複数存在し、複数のＲ_ZおよびＲ_Xは、各々同じであってもよいし異なっていてもよい。ｉは２～１０の整数を示し、ｐは１～６００の整数を示し、ｎは１～３０００の整数を示す。）

(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. Plural R _Z and R _X each exist, and plural R _Z and R Each _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.)

Further, the polycarbonate resin composition according to the present invention is characterized in that i in the general formula (1) is 3 or 4 in the above invention.

Further, the polycarbonate resin composition according to the present invention, in the above invention, further contains 0.005 to 0.5 parts by mass of a phosphorus stabilizer (C) with respect to 100 parts by mass of the polycarbonate resin (A). characterized in that

Further, in the polycarbonate resin composition according to the present invention, in the above invention, the weight average molecular weight (Mw) of the polyether constituting the polyether polycarbonate resin (B) is determined by gel permeation chromatography using chloroform as a solvent. It is characterized by being 600 to 8000 in terms of polystyrene.

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

A molded article according to the present invention is characterized by comprising the polycarbonate resin composition according to any one of the above inventions.

Further, the molded product according to the present invention is characterized in that it is an optical component in the above invention.

The polycarbonate resin composition and the molded article according to the present invention have high fluidity and good hue, are excellent in transparency, and have the effect of being able to greatly reduce mold contamination due to gas generation during molding. Play.

FIG. 1 is a schematic diagram showing an example of a drop-shaped mold used for mold contamination evaluation in Examples of the present invention.

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

The polycarbonate resin composition according to the embodiment of the present invention contains 0.01 to 5 parts by mass of the polyether polycarbonate resin (B) per 100 parts by mass of the polycarbonate resin (A). In this polycarbonate resin composition, the polyether polycarbonate resin (B) has a weight average molecular weight (Mw) of 8,000 to 40,000 in terms of polystyrene 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, a molded article made of the polycarbonate resin composition, and the like will be described in detail.

[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 polyether and carbonate bonds.

Specifically, the polyether of the polyether polycarbonate resin (B) is, for example, polyalkylene glycol. This polyalkylene glycol may or may not have a substituent. The polyether polycarbonate resin (B) is composed of such polyether and carbonate bonds. In the present invention, the polyether polycarbonate resin (B) is preferably a copolymer formed by carbonate-bonding polyalkylene glycol, that is, a copolymer represented by the following general formula (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. A plurality of each of R _Z and R _X exist, and these plurality of R _Z and R _X may be the same or different. i represents an integer from 2 to 10; p represents an integer from 1 to 600; n represents an integer from 1 to 3,000.

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 polyalkylene glycol with phosgene, or a method of reacting polyalkylene glycol with a carbonate precursor such as ethylene carbonate or diphenyl carbonate.

Various polyalkylene glycols can be used as the polyalkylene glycol which may have a substituent in the polyether polycarbonate resin (B). For example, preferred polyalkylene glycols include branched polyalkylene glycols represented by the following general formula (2).

In general formula (2), R represents an alkyl group having 1 to 3 carbon atoms. q represents an integer from 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.

Preferable specific examples of the branched polyalkylene glycol represented by formula (2) include polypropylene glycol and polybutylene glycol. The polypropylene glycol is a branched polyalkylene glycol in which R=CH ₃ (methyl group) in general formula (2), and a polyalkylene glycol in which i=2, R _Z =CH ₃ and R _X =H in general formula (1). It is an ether polycarbonate resin (B). The above polybutylene glycol is a branched polyalkylene glycol in which R=CH ₃ CH ₂ (ethyl group) in general formula (2), and i=2 and R _Z =CH ₃ CH ₂ in general formula (1). , R _x =H polyether polycarbonate resin (B). Commercially available products of such branched polyalkylene glycols include, for example, trade names “Uniol D-1000” and “Uniol PB-1000” manufactured by NOF Corporation.

Further, in the polyether polycarbonate resin (B), the polyalkylene glycol which may have a substituent may be linear polyalkylene glycol. Examples of the linear polyalkylene glycol include polyethylene glycol (i=2 and R _Z =R _X =H in general formula (1)), 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 =H), and the like are preferred. Among them, polytrimethylene glycol or polytetramethylene glycol is particularly preferable as the polyalkylene glycol. That is, i in general formula (1) is particularly preferably 3 or 4. Moreover, the substituents (R _Z and R _X in the general formula (1)) of the polyalkylene glycol are preferably hydrogen atoms.

Commercially available polytrimethylene glycols include commercially available polytrimethylene glycols in which R _Z and R _X in general formula (1) are hydrogen atoms. Commercially available products of this polytrimethylene glycol include, for example, the product name "Velvetol" manufactured by Allessa. Moreover, commercial products of polytetramethylene glycol include commercial products of polytetramethylene glycol in which R _Z and R _X in the general formula (1) are hydrogen atoms. Commercially available products of this polytetramethylene glycol include, for example, the product name "PTMG" manufactured by Mitsubishi Chemical Corporation.

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

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

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

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

Examples of the linear alkylene ether unit represented by the general formula (3) include glycols, ethylene glycol in which p is 2 in general formula (3), triglyceride in which p is 3 in general formula (3), methylene glycol, tetramethylene glycol in which p in general formula (3) is 4, pentamethylene glycol in which p in general formula (3) is 5, and hexamethylene glycol in which p in general formula (3) is 6 is mentioned. The linear alkylene ether unit may be a mixture of these. Among them, as the linear alkylene ether unit, trimethylene glycol and tetramethylene glycol are preferable, and tetramethylene glycol is particularly preferable.

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

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. mentioned. The branched alkylene ether unit represented by formula (4-1) may be a mixture of two or more of these. (2-methyl)ethylene glycol and (2-ethyl)ethylene glycol are preferable as the branched alkylene ether unit represented by the general formula (4-1).

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 and the like. The branched alkylene ether unit represented by formula (4-2) may be a mixture of two or more of these.

As the branched alkylene ether unit represented by the general formula (4-3), examples of glycol include (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 methylene glycol, (4,4-methylethyl)tetramethylene glycol, (4,4-diethyl)tetramethylene glycol and the like. The branched alkylene ether unit represented by formula (4-3) may be a mixture of two or more of these. Among them, (3-methyl)tetramethylene glycol is preferable as the branched alkylene ether unit represented by general formula (4-3).

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, (5,5-diethyl)pentamethylene glycol and the like. The branched alkylene ether unit represented by formula (4-4) may be a mixture of two or more of these.

In the above, the branched alkylene ether unit represented by each of the general formulas (4-1) to (4-4) was exemplified by glycol for convenience, but the branched alkylene ether unit is not limited to the above-described glycol, Alkylene oxides thereof and polyether-forming derivatives thereof may also be used.

As the polyalkylene glycol copolymer constituting the polyether polycarbonate resin (B), a copolymer composed of tetramethylene ether units and branched alkylene ether units represented by the general formula (4-3) is preferable, and in particular, A copolymer consisting of tetramethylene ether units and 3-methyltetramethylene ether units is more preferred. Further, as the polyalkylene glycol copolymer, a copolymer composed of a tetramethylene ether unit and a branched alkylene ether unit represented by the general formula (4-1) is also preferable. More preferred are copolymers composed of methylethylene ether units and copolymers composed of tetramethylene ether units and 2-ethylethylene ether units. Furthermore, as the polyalkylene glycol copolymer, a copolymer composed of a tetramethylene ether unit and a branched alkylene ether unit represented by the general formula (4-2) is also preferable, and a 2,2-dimethyltrimethylene ether unit. , that is, copolymers composed of neopentyl glycol ether units are also preferred.

Moreover, the polyalkylene glycol copolymer constituting the polyether polycarbonate resin (B) may be a random copolymer or a block copolymer.

In the polyalkylene glycol copolymer, a linear alkylene ether unit represented by the general formula (3) and a branched alkylene ether unit represented by each of the general formulas (4-1) to (4-4) The polymerization ratio is preferably 95/5 to 5/95 in terms of molar ratio of (linear alkylene ether unit)/(branched alkylene ether unit). The copolymerization ratio is more preferably 93/7 to 40/60, still more preferably 90/10 to 65/35, and particularly preferably rich in linear alkylene ether units. The above mole fraction is measured using a ¹ H-NMR spectrometer using deuterated chloroform as a solvent.

Among those mentioned 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, polytetra methylene glycol and the like. Copolymers particularly preferred as the polyalkylene glycol include polytetramethylene glycol-polyethylene glycol, polytetramethylene glycol-polytrimethylene glycol, polytetramethylene glycol-poly(2-methyl)ethylene glycol, and 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 and the like.

In addition, the polyalkylene glycol constituting the polyether polycarbonate resin (B) has a polyol such as 1,4-butanediol, glycerol, sorbitol, benzenediol, bisphenol A, hydrogenated bisphenol A, cyclohexanediol, and spiroglycol in the structure. It may contain the structure from which it originated. These organic groups can be imparted to the main chain by adding these polyols during polymerization of the polyalkylene glycol. Among them, particularly preferred are glycerol, sorbitol, bisphenol A and the like.

Examples of polyalkylene glycols containing organic groups in the structure include polyethylene glycol glyceryl ether, poly(2-methyl)ethylene glycol glyceryl ether, poly(2-ethyl)ethylene glycol glyceryl ether, polytetramethylene glycol glyceryl ether, Polyethylene glycol-poly(2-methyl)ethylene glycol glyceryl ether, polytetramethylene glycol-poly(2-methyl)ethylene glycol glyceryl ether, polytetramethylene glycol-poly(2-ethyl) polyethylene glycol glyceryl ether, polyethylene glycol sorbitol ether, poly(2-methyl)ethylene glycol sorbity ether, poly(2-ethyl)ethylene glycol sorbity ether, polytetramethylene glycol sorbity ether, polyethylene glycol-poly(2-methyl)ethylene glycol sorbity ether, poly Tetramethylene glycol - poly (2-methyl) ethylene glycol sorbity ether, polytetramethylene glycol - poly (2-ethyl) ethylene glycol sorbity 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, bisphenol A-bis(polytetramethylene glycol-poly(2-ethyl) polyethylene glycol) ether, etc. are preferred. It is mentioned as a thing.

The weight-average molecular weight (Mw) of the polyether (eg, polyalkylene glycol) constituting the polyether polycarbonate resin (B) is preferably 600-8,000. 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 6,000 or less, still more preferably 5,000 or less, and particularly preferably 4,000 or less. When the weight average molecular weight (Mw) of the polyalkylene glycol exceeds 8,000, 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) is lowered.

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, using a high-speed GPC apparatus "HLC-8320" manufactured by Tosoh Corporation, the column is HZ-M (4.6 mm × 150 mm) × 3 columns manufactured by Tosoh Corporation, chloroform is used as the eluent, and the measurement temperature is at 25° C., GPC is performed, and the polystyrene-equivalent molecular weight obtained by this is the weight-average molecular weight (Mw) in the present invention.

Carbonate precursors among the monomers used as raw materials for the polyether polycarbonate resin (B) include, for example, carbonyl halides and carbonate esters. As a raw material for the polyether polycarbonate resin (B), one kind of carbonate precursor may be used, or two or more kinds of carbonate precursors may be used together in an arbitrary combination and ratio.

Among the above carbonate precursors, carbonyl halides include, for example, haloformates such as bischloroformates obtained by reaction of phosgene and dihydroxy compounds, and monochloroformates of dihydroxy compounds.

Examples of carbonate esters include diaryl carbonates, dialkyl carbonates, carbonates of dihydroxy compounds, and the like. Examples of diaryl carbonates include diphenyl carbonate and ditolyl carbonate. Examples of dialkyl carbonates include dimethyl carbonate and diethyl carbonate. Examples of carbonate forms of dihydroxy compounds include biscarbonate forms of dihydroxy compounds, monocarbonate forms of dihydroxy compounds, and cyclic carbonates.

The method for producing the polyether polycarbonate resin (B) is not particularly limited, and any known method can be adopted. 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, a solid-phase transesterification method of a prepolymer, and the like. Among these, the melt transesterification method and the interfacial polymerization method are preferred, and the melt transesterification method is more preferred. Moreover, the kind of polyalkylene glycol itself used as the raw material of polyether polycarbonate resin (B) may be one kind, or may be two or more kinds. Further, the polyalkylene glycol, which is the raw material of the polyether polycarbonate resin (B), may contain a plurality of homopolymers, may contain a plurality of copolymers, or may contain a plurality of homopolymers. Mixtures of polymers and copolymers are also possible. For example, the polyalkylene glycol may contain a plurality of the branched polyalkylene glycols, may contain a plurality of the linear polyalkylene glycols, these branched polyalkylene glycols and It may also contain mixtures of linear polyalkylene glycols.

The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8,000-40,000. The lower limit of the weight average molecular weight (Mw) of this polyether polycarbonate resin (B) is preferably 10,000 or more, particularly preferably 12,000 or more. The upper limit of the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is preferably 37,000 or less, more preferably 35,000 or less, particularly preferably 30,000 or less, and 25,000 or less. is most preferred. 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. When the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is less than 8000, the polycarbonate resin composition tends to generate gas during molding of a molded article made of the polycarbonate resin composition (i.e., the amount of generated gas is increase).

The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is adjusted by selecting the Mw of polyalkylene glycol, which is one of the comonomer diol raw materials, by adjusting the ratio of the carbonate precursor, and by adding a terminating agent. It can be carried out by adding, adjusting the temperature and pressure during polymerization, and the like. For example, in the melt transesterification method, in order to increase the Mw of the polyether polycarbonate resin (B), the reaction ratio between the carbonate precursor monomer diphenyl carbonate and the diol monomer is close to 1. is adjusted, the polymerization temperature is kept high so that by-product phenol can be easily removed from the polymerization system, the pressure is kept as low as possible, and the interface is actively renewed by stirring.

The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) can be measured by the same method as the weight average molecular weight (Mw) of the polyether described above. Specifically, using a high-speed GPC apparatus "HLC-8320" manufactured by Tosoh Corporation, the column is HZ-M (4.6 mm × 150 mm) × 3 columns manufactured by Tosoh Corporation, chloroform is used as the eluent, and the measurement temperature is is 25° C. and GPC is performed, and the value of the polystyrene equivalent molecular weight obtained by this is the weight average molecular weight (Mw) of the polyether polycarbonate resin (B) in the present embodiment.

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 with respect 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 and 0.1 parts by mass or more with respect to 100 parts by mass of the polycarbonate resin (A). is more preferred. 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, relative to 100 parts by mass of the polycarbonate resin (A). It is particularly preferably 2 parts by mass or less. If 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. When the content of the polyether polycarbonate resin (B) exceeds 5 parts by mass, the polycarbonate resin composition becomes cloudy and loses transparency.

[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 polyether polycarbonate resin (B), and various resins can be used.

Specifically, polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbons directly bonded to the carbonic acid bonds are aromatic carbons, and aliphatic polycarbonate resins in which the carbons are aliphatic carbons. The polycarbonate resin (A) may be any of these resins. Among them, as the polycarbonate resin (A), an aromatic polycarbonate resin is preferable from the viewpoint of heat resistance, mechanical properties, electrical properties, and the like.

Among the monomers used as raw materials for the aromatic polycarbonate resin, aromatic dihydroxy compounds include, for example, dihydroxybenzenes, dihydroxybiphenyls, dihydroxynaphthalenes, dihydroxydiaryl ethers, bis(hydroxyaryl)alkanes, bis(hydroxyaryl ) cycloalkanes, cardo structure-containing bisphenols, dihydroxydiarylsulfides, dihydroxydiarylsulfoxides, dihydroxydiarylsulfones, and the like.

Examples of dihydroxybenzenes include 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (ie resorcinol), 1,4-dihydroxybenzene and the like. Examples of dihydroxybiphenyls include 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl and the like.

Dihydroxynaphthalenes include, for example, 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene and the like.

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, 1,3-bis(4-hydroxyphenoxy)benzene and the like.

Examples of bis(hydroxyaryl)alkanes include 2,2-bis(4-hydroxyphenyl)propane (that is, bisphenol A), 1,1-bis(4-hydroxyphenyl)propane, 2,2-bis( 3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane , 1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4 -hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane, α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene, 1 , 3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)cyclohexylmethane, bis(4-hydroxyphenyl)phenylmethane, bis (4-hydroxyphenyl)(4-propenylphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)naphthylmethane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1- Bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)-1-naphthylethane, 1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4 -hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)hexane, 2,2-bis(4-hydroxyphenyl)hexane, 1,1-bis (4-hydroxyphenyl)octane, 2,2-bis(4-hydroxyphenyl)octane, 4,4-bis(4-hydroxyphenyl)heptane, 2,2-bis(4-hydroxyphenyl)nonane, 1,1 -bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)dodecane and the like.

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-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane, 1,1-bis(4-hydroxyphenyl)-4- tert-butyl-cyclohexane, 1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane, 1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane and the like.

Cardo structure-containing bisphenols include, for example, 9,9-bis(4-hydroxyphenyl)fluorene and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene.

Examples of dihydroxydiarylsulfides include 4,4'-dihydroxydiphenylsulfide and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfide.

Dihydroxydiarylsulfoxides include, for example, 4,4'-dihydroxydiphenylsulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfoxide.

Examples of dihydroxydiarylsulfones include 4,4'-dihydroxydiphenylsulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone.

Among these, bis(hydroxyaryl)alkanes are preferred. Among bis(hydroxyaryl)alkanes, bis(4-hydroxyphenyl)alkanes are preferred, and 2,2-bis(4-hydroxyphenyl)propane (ie, bisphenol A) is particularly preferred from the viewpoint of heat resistance.

As a 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 together in any combination and ratio.

Carbonate precursors among the monomers used as raw materials for the polycarbonate resin (A) include, for example, carbonyl halides and carbonate esters. As a raw material for the polycarbonate resin (A), one kind of carbonate precursor may be used, or two or more kinds of carbonate precursors may be used together in an arbitrary combination and ratio.

Among the above carbonate precursors, carbonyl halides include, for example, haloformates such as bischloroformates obtained by reaction of phosgene and dihydroxy compounds, and monochloroformates of dihydroxy compounds.

Examples of carbonate esters include diaryl carbonates, dialkyl carbonates, carbonates of dihydroxy compounds, and the like. Examples of diaryl carbonates include diphenyl carbonate and ditolyl carbonate. Examples of dialkyl carbonates include dimethyl carbonate and diethyl carbonate. Examples of carbonate forms of dihydroxy compounds include biscarbonate forms of dihydroxy compounds, monocarbonate forms of dihydroxy compounds, and cyclic carbonates.

The method for producing the polycarbonate resin (A) is not particularly limited, and any method can be adopted. Examples of the method for producing the polycarbonate resin (A) include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, a solid-phase transesterification method of a prepolymer, and the like. Among these, the interfacial polymerization method is particularly preferred.

The molecular weight of polycarbonate resin (A) is preferably 10,000 to 30,000 in terms of viscosity average molecular weight (Mv) converted from solution viscosity measured at 25° C. using methylene chloride as a solvent. The lower limit of the viscosity average molecular weight (Mv) of the polycarbonate resin (A) is more preferably 10,500 or more, still more preferably 11,000 or more, particularly preferably 11,500 or more, and 12,000 or more. is most preferred. The upper limit of the viscosity-average molecular weight (Mv) of the polycarbonate resin (A) is more preferably 24,000 or less, even more preferably 20,000 or less. By setting the viscosity average molecular weight (Mv) of the polycarbonate resin (A) to 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 30000 or less, the decrease in fluidity of the polycarbonate resin composition of the present invention is suppressed, and the fluidity of the polycarbonate resin composition is improved (high fluidity (ensure quality). As a result, the moldability of the polycarbonate resin composition is enhanced, and thin-wall molding can be easily performed.

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

In the present invention, the viscosity average molecular weight (Mv) is determined by using methylene chloride as a solvent and using an Ubbelohde viscometer to determine the intrinsic viscosity [η] (unit dl / g) at a temperature of 25 ° C., Schnell's viscosity It means the value calculated from the formula: η=1.23×10 ⁻⁴ Mv ^0.83 . Also, the intrinsic viscosity [η] is a value obtained by measuring the specific viscosity [η _sp ] at each solution concentration [c] (g/dl) and using the following formula.

The terminal hydroxyl group concentration of the polycarbonate resin (A) is arbitrary and may be selected and determined as appropriate. For example, the terminal hydroxyl group concentration of the polycarbonate resin (A) is 1000 ppm or less, preferably 800 ppm or less, more preferably 600 ppm or less. By setting the upper limit of the terminal hydroxyl group concentration in this manner, 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, particularly when the polycarbonate resin (A) is produced by a melt transesterification method, and 40 ppm. It is more preferable to be above. By setting the lower limit of the terminal hydroxyl group concentration in this way, the decrease in the molecular weight of the polycarbonate resin (A) is suppressed, and the mechanical properties of the polycarbonate resin composition containing the polycarbonate resin (A) are further improved. be able to.

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

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

Further, 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 undergone deterioration such as thermal deterioration and aged deterioration. This is because the hue and mechanical properties of the polycarbonate resin composition containing the polycarbonate resin (A) may be deteriorated.

[Phosphorus 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 a phosphorus stabilizer (C) in addition to the polycarbonate resin (A) and polyether polycarbonate resin (B) described above. By containing the phosphorus-based stabilizer (C), the polycarbonate resin composition has a better hue and more excellent resistance to heat discoloration.

Any known phosphorus stabilizer (C) can be used. Examples of the phosphorus-based stabilizer (C) include phosphorus oxoacids, acidic metal pyrophosphates, group 1 or group 2B metal phosphates, phosphate compounds, phosphite compounds, phosphonite compounds, and the like. Among these, a phosphite compound is particularly preferable as the phosphorus-based stabilizer (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.

Phosphorus oxoacids include, for example, phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid. Examples of the acid metal pyrophosphate include sodium acid pyrophosphate, potassium acid pyrophosphate, calcium acid pyrophosphate, and the like. Phosphates of Group 1 or Group 2B metals include, for example, potassium phosphate, sodium phosphate, cesium phosphate, zinc phosphate, and the like.

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 triphenylphosphite, tris(monononylphenyl)phosphite, tris(monononyl/dinonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, Phyto, monooctyldiphenylphosphite, dioctylmonophenylphosphite, monodecyldiphenylphosphite, didecylmonophenylphosphite, tridecylphosphite, trilaurylphosphite, tristearylphosphite, distearylpentaerythritol diphosphite, Bis(2,4-di-tert-butyl-4-methylphenyl)pentaerythritol phosphite, bis(2,6-di-tert-butylphenyl)octylphosphite, 2,2-methylenebis(4,6-di -tert-butylphenyl)octylphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-diphosphite, 6-[3-(3-tert-butyl-hydroxy-5-methyl phenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]-dioxaphosphepin and the like.

Among the phosphite compounds described above, aromatic phosphite compounds represented by the following general formula (5) or general formula (6) are particularly preferred from the viewpoint of improving the heat discoloration resistance of the polycarbonate resin composition of the present invention. It is more preferable because it is effective.

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

In general formula (6), R ⁴ and R ⁵ , which may be the same or different, represent an aryl group having 6 or more and 30 or less carbon atoms.

Examples of the aromatic phosphite compound represented by the general formula (5) include triphenylphosphite, tris(monononylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, and the like. Among these, tris(2,4-di-tert-butylphenyl)phosphite is more preferred. 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, Examples include "Irgafos 168" manufactured by BASF, "JP-650" manufactured by Johoku Chemical Industry Co., Ltd., and the like.

Examples of the aromatic phosphite compound represented by the general formula (6) include 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 and the like, those having a pentaerythritol diphosphite structure are particularly preferred. Preferred specific examples of such aromatic phosphite compounds include "ADEKA STAB PEP-24G" and "ADEKA STAB PEP-36" manufactured by ADEKA, and "Doverphos S-9228" manufactured by Doverchemical.

Among the phosphite compounds described above, the aromatic phosphite compound represented by the general formula (6) is particularly preferred as the phosphorus-based stabilizer (C). This is because the inclusion of the aromatic phosphite compound makes the polycarbonate resin composition of the present invention more excellent in hue.

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

When the polycarbonate resin composition of the present invention contains a phosphorus stabilizer (C), the content of the phosphorus stabilizer (C) is 100 parts by mass of the polycarbonate resin (A) in the polycarbonate resin composition. On the other hand, it is 0.005 to 0.5 parts by mass. The lower limit of the content of the phosphorus stabilizer (C) is preferably 0.007 parts by mass or more, more preferably 0.008 parts by mass or more, and 0.01 parts by mass or more. is particularly preferred. The upper limit of the content of the phosphorus stabilizer (C) is preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, and 0.2 parts by mass or less. It is more preferable that the amount is 0.1 parts by mass or less.

If the content of the phosphorus-based stabilizer (C) is less than 0.005 parts by mass, the effect of improving the hue and heat discoloration resistance of the polycarbonate resin composition due to the inclusion of the phosphorus-based stabilizer (C) may not be obtained. There is 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 rather deteriorate. Furthermore, the moist heat stability of the polycarbonate resin composition may be lowered.

[Epoxy compound (D)]
Next, the epoxy compound (D) applied to the polycarbonate resin composition according to the embodiment of the invention will be described in detail. The polycarbonate resin composition may further contain an epoxy compound (D) in addition to the polycarbonate resin (A) and polyether polycarbonate resin (B) described above. 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.

As the epoxy compound (D), for example, a compound having one or more epoxy groups in one molecule is used. Preferred specific examples of such epoxy compounds (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′-methylcyclohexylcarboxylate, 2,3-epoxycyclohexylmethyl-3′,4′-epoxycyclohexylcarboxylate, 4-(3 ,4-epoxy-5-methylcyclohexyl)butyl-3′,4′-epoxycyclohexyl carboxylate, 3,4-epoxycyclohexyl ethylene oxide, cyclohexylmethyl 3,4-epoxycyclohexyl carboxylate, 3,4-epoxy-6- Methylcyclohexylmethyl-6′-methylsilohexyl carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopenta Dienyl ether, bis-epoxyethylene glycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxytalate, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5 -dimethyl-1,2-epoxycyclohexane, 3-methyl-5-t-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxylate, 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 ,5-epoxy tetrahydrophthalic anhydride, 3-t-butyl-4,5-epoxy tetrahydrophthalic anhydride, diethyl 4,5-epoxy cis-1,2-cyclohexyldicarboxylate, di-n-butyl-3-t-butyl-4,5-epoxy-cis-1,2-cyclohexyldicarboxylate, epoxidized soybean oil, epoxidized linseed oil and the like.

Among these epoxy compounds (D), alicyclic epoxy compounds are preferably used. Especially preferred is 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate.

Moreover, as the epoxy compound (D), a polyalkylene glycol derivative having an epoxy group at one end or both ends can also be preferably used. In particular, polyalkylene glycol having epoxy groups at both ends is preferred.

Preferred specific examples of the above polyalkylene glycol derivatives include 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, polytetramethylene glycol-poly(2-ethyl)ethylene glycol diglycidyl ether, etc. Examples include polyalkylene glycol derivatives containing epoxy groups in the structure.

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

When the polycarbonate resin composition of the present invention contains the epoxy compound (D), the preferred content of the epoxy compound (D) is 0.0005 to 0.2 per 100 parts by mass of the polycarbonate resin (A). part by mass. 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. preferable. 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 0.05 parts by mass or less. is particularly preferred.

If the content of the epoxy compound (D) is less than 0.0005 parts by mass, the effect of improving the hue 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) exceeds 0.2 parts by mass, the heat discoloration resistance of the polycarbonate resin composition may rather deteriorate. Furthermore, the hue and wet heat stability of the polycarbonate resin composition may deteriorate.

[Oxetane compound (E)]
Next, the oxetane compound (E) applied to the polycarbonate resin composition according to the embodiment of the invention will be described in detail. The polycarbonate resin composition may further contain an oxetane compound (E) in addition to the polycarbonate resin (A) and polyether polycarbonate resin (B) described above. 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.

As the oxetane compound (E), for example, any compound can be used as long as it is a compound having one or more oxetane groups in the molecule. That is, both monooxetane compounds having one oxetane group in the molecule and bifunctional or higher polyoxetane compounds having two or more oxetane groups in the molecule can be used as the oxetane compound (E). By containing the oxetane compound (E), the polycarbonate resin composition of the present invention can have a better hue and further improve heat discoloration resistance.

Preferred specific examples of the monooxetane compound include compounds represented by the following general formula (III-a), compounds represented by general formula (III-b), compounds represented by general formula (IV), and the like. mentioned.

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

In general formula (III-a), general formula (III-b) and general formula (IV), R ¹ is an alkyl group as described above, but is an alkyl group having 1 to 6 carbon atoms. is preferred, a methyl group or an ethyl group is more preferred, and an ethyl group is particularly preferred.

In general formula (III-b), R ² is an alkyl group or a phenyl group as described above, preferably an alkyl group having 2 to 10 carbon atoms. The alkyl group having 2 to 10 carbon atoms may be a chain alkyl group, a branched alkyl group or an alicyclic alkyl group, and an ether bond (etheric oxygen atom) in the middle of the alkyl chain. may be a chain or branched alkyl group having Specific examples of R ² include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, 3-oxypentyl, cyclohexyl, phenyl and the like. Among these, R ² is preferably a 2-ethylhexyl group, a phenyl group or a cyclohexyl group.

Preferred specific examples of the compound represented by formula (III-a) include 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3 -hydroxymethyl-3-n-butyloxetane, 3-hydroxymethyl-3-propyloxetane and the like. Among these, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane and the like are particularly preferred. Further, as a specific example of the compound represented by general formula (III-b), 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane and the like are particularly preferable.

In general formula (IV), R ³ is a divalent organic group which may or may not have an aromatic ring, as described above. Specific examples of R ³ include linear or branched C 1-12 alkylene groups such as ethylene, propylene, butylene, neopentylene, n-pentamethylene and n-hexamethylene; a phenylene group, a divalent group represented by the formula: -CH ₂ -Ph-CH ₂ - or -CH ₂ -Ph-Ph-CH ₂ - (Ph in the formula represents a phenyl group), hydrogenated bisphenol A residue, hydrogenated bisphenol F residue, hydrogenated bisphenol Z residue, cyclohexanedimethanol residue, tricyclodecanedimethanol residue and the like can be mentioned.

Specific preferred 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, 1,4-bis[(3-ethyl-3-oxetanyl)methoxy methyl]benzene and the like.

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. good.

When the polycarbonate resin composition of the present invention contains the oxetane compound (E), the preferred content of the oxetane compound (E) is 0.0005 to 0.2 per 100 parts by mass of the polycarbonate resin (A). part by mass. The lower limit of the content of the oxetane compound (E) is more preferably 0.001 parts by mass or more, still more preferably 0.003 parts by mass or more, and preferably 0.005 parts by mass or more. Especially preferred. The upper limit of the content of the oxetane compound (E) is more preferably 0.15 parts by mass or less, further preferably 0.1 parts by mass or less, and 0.05 parts by mass or less. is particularly preferred.

If the content of the oxetane compound (E) is less than 0.0005 parts by mass, the effect of improving the hue 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 rather deteriorate. Furthermore, there is a possibility that gas is likely to be generated during molding of the polycarbonate resin composition.

It is also preferred that the polycarbonate resin composition of the present invention 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 with respect to 100 parts by mass of the polycarbonate resin (A).

[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 components such as the polycarbonate resin (A) and the polyether polycarbonate resin (B). Examples of such additives include antioxidants, release agents, ultraviolet absorbers, fluorescent brighteners, pigments, dyes, polymers other than polycarbonate resins, flame retardants, impact modifiers, antistatic agents, plasticizers, agents, compatibilizers, and the like. Examples of polymers other than the polycarbonate resin include polyalkylene glycol. The polyalkylene glycol that the polycarbonate resin composition may contain has, for example, the same structure as the polyalkylene glycol that constitutes the polyether polycarbonate resin (B) described above. The polycarbonate resin composition may contain one of these additives, or may contain two or more of these additives.

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 the polycarbonate resin (A) and the polyether It 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 3 parts by mass or less with respect to the total 100 parts by mass of the polycarbonate resin (B). It is particularly preferred to have

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

Each of the initial YI value and the degree of yellowing ΔYI takes a value equal to or lower than a preset threshold value. For example, when the light from the light source passes through a 300 mm optical path in the polycarbonate resin composition, the threshold for the initial YI value is set to 25.0 and the threshold for the yellowness 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 deterioration test and the initial YI value, that is, the degree of yellowing ΔYI, is preferably 6.5 or less. As the accelerated deterioration test, for example, a polycarbonate resin composition is held at a temperature of 95° C. for 1000 hours.

When the initial YI value exceeds 25.0, the light (transmitted light) after passing through an optical path of 300 mm in the polycarbonate resin composition in the initial state is compared to the light emitted from the light source, and the polycarbonate It is yellowed to the extent that it exceeds the permissible hue change for the resin composition (for example, to the extent that it can be confirmed by visual inspection). Further, when the yellowing degree ΔYI exceeds 6.5, the light passing through the optical path of 300 mm in the polycarbonate resin composition after the accelerated deterioration test is transmitted light having a hue represented by the initial YI value. Compared to , it is yellowed to the extent that it exceeds the permissible hue change for the polycarbonate resin composition.

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

[Molding]
Next, the 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. For example, the molded article is produced by molding pellets obtained by pelletizing the polycarbonate resin composition by various molding methods can do. Moreover, the molded article of the present invention may be produced by directly molding the polycarbonate resin composition melt-kneaded by an extruder without going through the pellets.

Since the molded article produced by the above molding method is made of the polycarbonate resin composition of the present invention, it has a good hue and excellent resistance to heat discoloration, and is also excellent in transparency. Examples of such molded products include optical components such as light guide plates. The hue and heat discoloration resistance of the molded article are represented by the initial YI value and the degree of yellowing ΔYI, respectively, as with the polycarbonate resin composition described above. That is, the initial YI value of the molded product at an optical path length of 300 mm is preferably 25.0 or less, and the yellowing degree ΔYI of the molded product at an optical path length of 300 mm is preferably 6.5 or less.

As described above, the polycarbonate resin composition of the present invention has high fluidity and good hue, is excellent in transparency, and can greatly reduce mold contamination due to gas generation during molding. be. Therefore, it is possible to easily obtain a molded product such as an optical component that enjoys the effects of the polycarbonate resin composition by a desired molding method such as injection molding. In particular, the polycarbonate resin composition of the present invention is suitably used for molding thin-walled and large-sized optical parts that are likely to cause mold contamination.

Further, 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, especially when manufacturing a large thin-walled molded product. ~400°C is preferred. The lower limit of the resin temperature is more preferably 310° C. or higher, still 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 less. When a conventional polycarbonate resin composition is used, there is a problem that if the resin temperature during molding is increased in order to mold a large thin-walled molded product, the obtained molded product tends to yellow. On the other hand, by using the polycarbonate resin composition of the present invention, it is possible to produce a molded article having a good hue and excellent transparency even in the above temperature range, especially a large and thin optical part. It becomes possible to When it is difficult to directly measure the resin temperature, the resin temperature is set at the barrel set temperature during molding.

Here, a large thin molded product has a thickness of 1 mm or less, preferably 0.8 mm or less, more preferably 0.6 mm or less, and has a vertical or horizontal length or diameter corresponding to the optical path length. A molded product having a plate-like part with a dimension of 100 mm or more. The plate-like portion may be flat plate-like or curved plate-like. The surface of the plate-like portion may be a flat surface or a surface having unevenness or the like. Moreover, the cross section of the plate-like portion may have an inclined surface, a wedge-shaped cross section, or the like.

Examples of optical components of the present invention include parts of equipment and instruments that directly or indirectly use light sources such as LEDs (Light Emitting Diodes), organic ELs (Electro Luminescence), incandescent lamps, fluorescent lamps, and cathode tubes. Typical examples of such optical components include a light guide plate and surface light emitter members. A light guide plate guides light from a light source such as an LED in a liquid crystal backlight unit, various display devices, and lighting devices. For example, a light guide plate normally diffuses light received from a side surface or a back surface by irregularities provided on the surface to emit uniform light. In general, the shape of the light guide plate is flat. The surface of the light guide plate may or may not have unevenness. Further, the light guide plate is preferably molded by a molding method such as injection molding, ultra-high speed injection molding, injection compression molding, melt extrusion molding (for example, T-die molding).

A light guide plate molded using the polycarbonate resin composition of the present invention has good hue and excellent transparency without white turbidity or decrease in transmittance, and less molding defects due to mold contamination.

A 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 a light guide plate is applied include mobile phones, mobile notebooks, netbooks, slate PCs (personal computers), tablet PCs, smartphones, various mobile terminals such as tablet terminals, cameras, clocks, and desktops. type or laptop type (notebook type) PCs, various displays, lighting equipment, and the like.

Moreover, the shape of the optical component molded using the polycarbonate resin composition of the present invention may be either film-like or sheet-like. Specific examples of this optical component include, for example, a light guide film.

In addition to the light guide plate for the above-mentioned applications, the optical component of the present invention can also be used in vehicle lighting equipment such as headlights (headlamps), rear lamps and fog lamps for automobiles and motorcycles to emit light from light sources such as LEDs. It can also be suitably used as a light guide or lens for guiding light.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples. The present invention should not be construed as being limited to the following examples.

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

The polymerization apparatus restored to pressure as described above was immersed in an oil bath, and the polytetramethylene glycol and DPC in the polymerization apparatus were polymerized. In Production Example 1, these polymerization reactions started when the polymerization apparatus was immersed in an oil bath. The temperature and pressure in this polymerization apparatus were set according to the temperature elevation/pressure reduction program shown in Table 1 below. Specifically, the set temperature in the polymerization apparatus is set to 200° C. at the start of polymerization, raised to 217° C. after 10 minutes have passed since the start of polymerization, and then maintained at 217° C. until 170 minutes have passed since the start of polymerization. did. The set pressure of this polymerization apparatus was set to 97 kPaA at the start of polymerization, and thereafter, the pressure was gradually reduced, and after 100 minutes from the start of polymerization, the pressure was reduced to 0.13 kPaA or less with a vacuum pump full vacuum (F.V.). This reduced set pressure was maintained until 170 minutes after the start of polymerization, and increased to 100 kPaA after 170 minutes. The polymerization reaction between polytetramethylene glycol and DPC in this polymerization apparatus proceeded under such temperature and pressure conditions, and the polymerization was completed 170 minutes after the start of polymerization.

In Production Example 1, a polytetramethylene glycol-polycarbonate copolymer was obtained by the above-described polymerization reaction of polytetramethylene glycol and DPC. The weight average molecular weight (Mw) of the obtained polytetramethylene glycol-polycarbonate copolymer was 21,700. Hereinafter, the polytetramethylene glycol-polycarbonate copolymer produced in Production Example 1 is referred to as polyether polycarbonate resin (B1).

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

(Examples 1 to 18, Comparative Examples 1 to 4)
[Components of Polycarbonate Resin Composition]
Each component of the polycarbonate resin composition in each of Examples 1-18 and Comparative Examples 1-4 is as shown in Table 3. In each of Examples 1 to 18 and Comparative Examples 1 to 4, polycarbonate resin (A), polyether polycarbonate resin (B), polyalkylene glycol (X), phosphorus stabilizer (C), epoxy compound shown in Table 3 (D), an oxetane compound (E) and a release agent (F) are optionally used.

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

[Method for producing pellets of polycarbonate resin composition]
In each of Examples 1 to 18 and Comparative Examples 1 to 4, each component shown in Table 3 above was blended in the proportions (parts by mass) shown in Tables 4-1 to 4-3 below and placed in a tumbler. Mix for 20 minutes. Subsequently, using a vented single-screw extruder with a screw diameter of 40 mm ("VS-40" manufactured by Tanabe Plastic Machinery Co., Ltd.), the cylinder temperature was set to 240 ° C., and the mixture of the above components was melt-kneaded, thereby producing a polycarbonate. A resin composition was produced. Thereafter, a strand of this polycarbonate resin composition was extruded, and the extruded strand was cut (pelletized) to obtain pellets of this polycarbonate resin composition.

[Strand transparency evaluation]
In each of Examples 1 to 18 and Comparative Examples 1 to 4, strand transparency evaluation was performed on strands obtained during pellet production of the polycarbonate resin composition. Specifically, in the process of producing pellets of the polycarbonate resin composition described above, the transparency of the strand extruded from the extruder was visually determined based on the following evaluation criteria.
<Evaluation Criteria>
A: The extruded strand has extremely high transparency, and the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) or polyalkylene glycol is extremely good.
B: The extruded strand has high transparency, and the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) or polyalkylene glycol is good.
C: The extruded strand is cloudy, and the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) or polyalkylene glycol is poor.
D: The extruded strand is extremely cloudy, and the compatibility between the polycarbonate resin (A) and the polyether polycarbonate resin (B) or polyalkylene glycol is extremely poor.

[Evaluation of mold contamination in injection molding (evaluation of mold deposits)]
In each of Examples 1 to 18 and Comparative Examples 1 to 4, mold contamination due to gas generation during injection molding of the polycarbonate resin composition was evaluated. Specifically, the pellets obtained by the above production method are dried at 120 ° C. for 5 hours, then supplied to an injection molding machine ("SE7M" manufactured by Sumitomo Heavy Industries, Ltd.), and as shown in FIG. Using the drop-shaped mold 1, 100 shots of injection molding of the polycarbonate resin composition were performed. The injection molding conditions were a cylinder temperature of 340°C, a molding cycle of 10 seconds, and a mold temperature of 40°C. In the evaluation of mold contamination, the drop-shaped mold 1 after the above injection molding was visually inspected for the state of contamination due to white deposits generated on the metal mirror surface on the fixed side of the mold based on the following evaluation criteria. determined by
<Evaluation Criteria>
A: There is very little deposit on the mold, and the mold contamination resistance is extremely good.
B: There is little deposit on the mold, but some contamination of the mold due to the deposit is observed.
C: The amount of deposits on the mold is rather large, and the mold is found to be contaminated by the deposits.
D: A lot of deposits on the mold, and conspicuous contamination of the mold by the deposits is observed.

As shown in FIG. 1, the drop-shaped mold 1 is provided with a drop-shaped mold body and a portion of the mold body opposite to the pointed end P (hereinafter referred to as a base end). It is a mold provided with a gate G. The drop-shaped mold 1 is designed so that the polycarbonate resin composition is introduced from the gate G, and the generated gas from the polycarbonate resin composition tends to accumulate in the inner portion of the tip P. The deposits generated on the drop-shaped mold 1 originate from the generated gas from the polycarbonate resin composition.

For example, in the drop-shaped mold 1, the gate G has a width of 1 mm and a thickness of 1 mm. Further, as shown in FIG. 1, the width h1 is the maximum width of the drop shape of the drop mold 1, and is set to 14.5 mm. The length h2 is the length between the base end of the drop-shaped mold 1 and the maximum width portion, and is set to 7 mm. The length h3 is the length between the base end portion and the pointed end portion P of the drop-shaped mold 1, and is set to 27 mm. The thickness of the molding portion (mold main body) of the drop-shaped mold 1 is set to 3 mm. It should be noted that the drawings are schematic, and the dimensional relationship of each element, the ratio of each element, and the like shown in the drawings may differ from the actual ones.

[Evaluation of hue and heat discoloration resistance]
In each of Examples 1 to 18 and Comparative Examples 1 to 4, the optical path made of the polycarbonate resin composition was evaluated for hue and heat discoloration resistance. Specifically, the pellets obtained by the above production method are dried at 120° C. for 5 to 7 hours with a hot air circulation dryer, and then supplied to an injection molding machine ("HSP100A" manufactured by Sodick). Using an injection molding machine, the polycarbonate resin composition was injection molded to form a long optical path molded product. As conditions for this injection molding, the resin temperature (cylinder temperature) was 340°C and the mold temperature was 80°C. The obtained long optical path molded article is a molded article made of a polycarbonate resin composition and having an optical path length of 300 mm. The size of this long optical path molded product is length×width×thickness=300 mm×7 mm×4 mm.

In evaluating the hue, the initial YI value, which is an index for judging the quality of the hue of the polycarbonate resin composition, was measured. Specifically, the initial YI value at an optical path length of 300 mm was measured for the long optical path molded product. The initial YI value is measured by transmitting light through the optical path (optical path length: 300 mm) of the long optical path molded product, and passing the light through the light receiving geometric condition e (0 °: 0 °) in accordance with JIS Z 8722. can be performed by receiving light with a light receiving portion at and measuring YI calculated according to ASTM D 1925. For the measurement of the initial YI value, a long-path spectral transmission colorimeter ("ASA 1" manufactured by Nippon Denshoku Industries Co., Ltd., C light source, 2° field of view) was used.

In the evaluation of the heat discoloration resistance, a yellowing index ΔYI was derived, which is an index for determining the quality of the heat discoloration resistance of the polycarbonate resin composition. Specifically, the long optical path molded product whose initial YI value was measured was held 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. The degree of yellowing ΔYI, which is the difference between the obtained YI value and the initial YI value, was determined. The YI value in the evaluation of thermal discoloration resistance can be measured by the same method as the initial YI value described above, except that the object to be measured is a long optical path molded product after being held in a high temperature environment.

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

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

In Examples 1 to 18, the initial YI value and the degree of yellowing 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. Specifically, in any of Examples 1 to 18, the initial YI value is a value equal to or less than the initial YI value threshold (= 25.0) when the target optical path length is 300 mm, and yellow The degree of change ΔYI was a value equal to or less than the threshold value (=6.5) of the degree of yellowing ΔYI when the target optical path length was 300 mm. From these results, it was confirmed that all of the polycarbonate resin compositions of Examples 1 to 18 had good initial hue and excellent resistance to heat discoloration.

On the other hand, as shown in Table 4-3, in Comparative Examples 1 and 4, the results of strand transparency evaluation were good, but in Comparative Examples 2 and 3, the results of strand transparency evaluation were poor. Further, Comparative Example 1 gave good results in mold contamination evaluation, but Comparative Examples 2 to 4 gave poor results in mold contamination evaluation.

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

In addition, the present invention is not limited to the above-described embodiments and examples, and the present invention also includes those configured by appropriately combining the respective constituent elements described above. In addition, other embodiments, examples, operation techniques, etc. made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

INDUSTRIAL APPLICABILITY The polycarbonate resin composition according to the present invention has high fluidity and good hue, is excellent in transparency, and causes very little mold contamination due to gas generation during molding. It can be very suitably used for optical parts such as light plates.

1 Drop-shaped mold G Gate P Tip

Claims (8)

Containing 0.01 to 5 parts by mass of a polyether polycarbonate resin (B) having a polyether and a carbonate bond with respect to 100 parts by mass of the polycarbonate resin (A),
The weight average molecular weight (Mw) of the polyether polycarbonate resin (B) is 8000 to 40000 in terms of polystyrene by gel permeation chromatography using chloroform as a solvent.
A polycarbonate resin composition characterized by: The polyether polycarbonate resin (B) is a copolymer represented by the following general formula (1),
The polycarbonate resin composition according to claim 1, characterized by:

(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. Plural R _Z and R _X each exist, and plural R _Z and R Each _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.) i in the general formula (1) is 3 or 4,
The polycarbonate resin composition according to claim 2, characterized in that: Further containing 0.005 to 0.5 parts by mass of a phosphorus stabilizer (C) with respect to 100 parts by mass of the polycarbonate resin (A),
The polycarbonate resin composition according to any one of claims 1 to 3, characterized in that: The weight average molecular weight (Mw) of the polyether constituting the polyether polycarbonate resin (B) is 600 to 8000 in terms of polystyrene by gel permeation chromatography using chloroform as a solvent.
The polycarbonate resin composition according to any one of claims 1 to 4, characterized in that: 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 and the initial YI value of the polycarbonate resin composition after being held at 95° C. for 1000 hours is 6.5 or less.
The polycarbonate resin composition according to any one of claims 1 to 5, characterized in that: Consisting of the polycarbonate resin composition according to any one of claims 1 to 6,
A molded product characterized by: is an optical component,
The molded article according to claim 7, characterized in that:

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