CN114466896B - polycarbonate resin composition - Google Patents

Abstract

A polycarbonate resin composition, characterized in that, relative to 100 parts by mass of the polycarbonate resin (A), it contains 0.1 to 10 parts by mass of a polycarbonate copolymer (B) and 0.005 to 0.005 parts by mass of a phosphorus-based stabilizer (C). 0.5 parts by mass, the polycarbonate copolymer (B) is formed based on carbonate bonds of (B1) bisphenol A and (B2) polypropylene glycol optionally having substituents.

Description

Polycarbonate resin composition

Technical Field

The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin composition having excellent impact resistance, good hue, and excellent transparency, and having extremely little gas generation and mold contamination during molding, and a molded product obtained by molding the polycarbonate resin composition.

Background Art

In order to meet the requirements of thinness, lightness, labor saving and high precision, a planar light source device is installed in a liquid crystal display device such as a personal computer and a mobile phone. In addition, in order to play the role of uniformly and effectively guiding the incident light to the liquid crystal display side, the planar light source device is equipped with a wedge-shaped cross-section light guide plate with a uniform inclined surface, or a flat light guide plate. In addition, there are those that form a concave-convex pattern on the surface of the light guide plate to give it a light scattering function.

Such a light guide plate can be obtained by injection molding of a thermoplastic resin, and the above-mentioned concavo-convex pattern can be imparted by transfer of the concavo-convex portion formed on the surface of the insert mold. At present, the light guide plate is molded from a resin material such as polymethyl methacrylate (PMMA), but recently, there is a trend to demand display devices that reflect more vivid images. Due to the tendency of the heat generated near the light source to increase the temperature inside the device, it is being replaced by a polycarbonate resin material with higher heat resistance.

Polycarbonate resin has excellent mechanical properties, thermal properties, electrical properties, and weather resistance, but its light transmittance is lower than that of PMMA, so when a light guide plate and a light source made of polycarbonate resin constitute a surface light source, there is a problem of low brightness. In addition, there is a recent demand to reduce the chromaticity difference between the incident part of the light guide plate and the position away from the incident part, but there is a problem that polycarbonate resin is more prone to yellowing than PMMA.

Patent document 1 proposes a method for improving light transmittance and brightness by adding acrylic resins and alicyclic epoxy compounds, Patent document 2 proposes a method for improving brightness by modifying the ends of polycarbonate resins and improving the transferability of concave and convex parts to light guide plates, and Patent document 3 proposes a method for improving brightness by introducing copolyester carbonates having aliphatic chain segments and improving the above-mentioned transferability.

However, in the method of Patent Document 1, although the hue is improved by adding an acrylic resin, the transmittance and brightness cannot be improved due to white turbidity, and the transmittance can be improved by adding an alicyclic epoxy compound, but the hue is not improved. In the case of Patent Documents 2 and 3, although the improvement effect of fluidity and transferability can be expected, there is a disadvantage of reduced heat resistance.

On the other hand, it is known that polyethylene glycol or poly(2-methyl)ethylene glycol is blended into thermoplastic resins such as polycarbonate resins. Patent Document 4 describes a polycarbonate resin containing the same and having gamma-ray resistance, and Patent Document 5 describes a thermoplastic resin composition blended into PMMA and the like and having excellent antistatic properties and surface appearance.

Patent Document 6 proposes to improve transmittance and hue by blending a polyalkylene glycol composed of a linear alkyl group, and to improve transmittance and yellowing degree (yellowness index: YI) by blending polytetramethylene ether glycol.

Furthermore, Patent Document 7 describes a method for producing a polycarbonate copolymer using a diol obtained by diesterification of a polyalkylene glycol as a raw material (comonomer). However, the diester diol of the polyalkylene glycol in the polycarbonate copolymer is unstable, has insufficient impact resistance, and has poor hue and heat discoloration resistance.

In particular, recently, in various portable terminals such as smart phones and tablet terminals, the thinning and enlargement of optical components such as light guide plates are being carried out at an alarming rate, and the molding of light guide plates requires high-temperature barrel temperatures and high-speed injection. Accompanying this, there are problems such as increased gas generated during molding and easy development of mold contamination. Therefore, for the resin composition used for these moldings, not only excellent optical properties are required, but also less mold contamination caused by gas generation during injection molding at high temperatures and excellent impact resistance.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Laid-Open No. 11-158364

Patent Document 2: Japanese Patent Application Publication No. 2001-208917

Patent Document 3: Japanese Patent Application Publication No. 2001-215336

Patent Document 4: Japanese Patent Application Laid-Open No. 1-22959

Patent Document 5: Japanese Patent Application Laid-Open No. 9-227785

Patent Document 6: Japanese Patent No. 5699188

Patent Document 7: Japanese Patent Application Publication No. 2006-016497

Summary of the invention

Problem that the invention aims to solve

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polycarbonate resin composition having good hue, excellent transparency, excellent impact resistance, and extremely little gas generation and mold contamination during molding.

Solutions for solving problems

The present inventors have conducted intensive studies to achieve the above-mentioned problems and have found that by blending a specific polycarbonate copolymer based on carbonate bonds of bisphenol A and polypropylene glycol with a specific amount of a phosphorus-based stabilizer into a conventional polycarbonate resin, a polycarbonate resin composition having excellent impact resistance, good hue, and further excellent transparency and extremely low gas generation and mold contamination during molding can be obtained, thereby completing the present invention.

The present invention relates to the following polycarbonate resin composition and molded article.

[1] A polycarbonate resin composition, characterized in that it contains 0.1 to 10 parts by mass of a polycarbonate copolymer (B) and 0.005 to 0.5 parts by mass of a phosphorus stabilizer (C) relative to 100 parts by mass of a polycarbonate resin (A), wherein the polycarbonate copolymer (B) is a carbonate-based bond of (B1) bisphenol A and (B2) polypropylene glycol optionally having a substituent.

[2] The polycarbonate resin composition according to [1] above, wherein the initial YI value at an optical path length of 300 mm is 25 or less, and the difference (ΔYI) between the YI value at an optical path length of 300 mm after being kept at 95° C. for 1000 hours and the initial YI value is 6 or less.

[3] The polycarbonate resin composition according to [1] or [2] above, wherein the weight average molecular weight (Mw) of the poly(n-propylene glycol) (B2) constituting the polycarbonate copolymer (B) is 600 to 8,000.

[4] The polycarbonate resin composition according to any one of [1] to [3] above, wherein the weight average molecular weight (Mw) of the polycarbonate copolymer (B) is 5,000 to 40,000.

[5] A polycarbonate resin composition according to any one of [1] to [4] above, wherein the mass ratio of bisphenol A (B1) and polypropylene glycol (B2) constituting the polycarbonate copolymer (B) is 5 mass % or more and less than 50 mass % and (B2) is more than 50 mass % and less than 95 mass % based on the total mass % of (B1) and (B2) of 100 mass %.

[6] The polycarbonate resin composition according to any one of [1] to [5] above, wherein the Charpy notched impact strength of a molded article having a thickness of 3 mm in accordance with ISO 179 is 25 kJ/m ² or more.

[7] A molded article of the polycarbonate resin composition according to any one of [1] to [6] above.

[8] The molded article according to [7] above, which is an optical component.

[9] A polycarbonate resin composition, characterized in that it contains 0.001 to 0.5 parts by mass of a stabilizer relative to 100 parts by mass of a polycarbonate resin (A), the initial YI value at an optical path length of 300 mm is 25 or less, and the difference (ΔYI) between the YI value at an optical path length of 300 mm after being kept at 95°C for 1000 hours and the initial YI value is 6 or less.

[10] The polycarbonate resin composition according to [9] above, wherein the stabilizer is a phosphorus-based stabilizer.

[11] The polycarbonate resin composition according to [9] or [10] above, wherein the Charpy notched impact strength of a molded article having a thickness of 3 mm in accordance with ISO 179 is 25 kJ/m ² or more.

Effects of the Invention

The polycarbonate resin composition of the present invention has excellent impact resistance, good hue, and excellent transparency, and generates very little gas and mold contamination during molding. The molded product formed therefrom has excellent impact resistance and is particularly suitable for use as an optical component with good hue and transparency. In particular, the polycarbonate copolymer (B) using (B2) polypropylene glycol in the present invention has high compatibility with the polycarbonate resin (A) and excellent transparency compared to a copolymer replaced with the similarly linear polytetramethylene glycol. Therefore, since the ratio of the polycarbonate copolymer (B) that can be mixed can be increased in practical terms, or a polycarbonate copolymer (B) with a higher molecular weight can be used, there is also an effect of expanding the range of resin design according to various uses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a water drop type mold used for evaluation of mold contamination in Examples.

DETAILED DESCRIPTION

Hereinafter, the present invention will be described in detail with reference to embodiments and examples.

In addition, in this specification, "to" is used as a meaning including the numerical value described before and after it as a lower limit and an upper limit unless otherwise specified.

The polycarbonate resin composition of the present invention is characterized in that it contains 0.1 to 10 parts by mass of a polycarbonate copolymer (B) and 0.005 to 0.5 parts by mass of a phosphorus-based stabilizer (C) relative to 100 parts by mass of a polycarbonate resin (A), wherein the polycarbonate copolymer (B) is a carbonate-based bond of (B1) bisphenol A and (B2) polypropylene glycol optionally having a substituent.

Hereinafter, each component constituting the polycarbonate resin composition of the present invention, the optical component, etc. will be described in detail.

[Polycarbonate copolymer (B) of (B1) bisphenol A and (B2) polypropylene glycol based on carbonate bonds]

The polycarbonate copolymer (B) used in the present invention is a polycarbonate copolymer based on a carbonate bond of (B1) bisphenol A and (B2) poly-n-propylene glycol which may have a substituent.

The mass ratio of bisphenol A (B1) and poly(n-propylene glycol) (B2) constituting the polycarbonate copolymer (B) is preferably 5% by mass or more and less than 50% by mass, and poly(n-propylene glycol) (B2) is more than 50% by mass and less than 95% by mass, based on the total of (B1) and (B2) being 100% by mass. It is more preferred that (B1) is 5% by mass or more and less than 40% by mass, and (B2) is 60% by mass or more and less than 95% by mass. It is further preferred that (B1) is 5% by mass or more and less than 35% by mass, and (B2) is 65% by mass or more and less than 95% by mass. When poly(n-propylene glycol) (B2) is 50% by mass or less, the hue of the polycarbonate resin composition deteriorates, and when it exceeds 95% by mass, the composition tends to be turbid.

The polycarbonate copolymer (B) is represented by the following general formula (1), and is a polycarbonate copolymer composed of polycarbonate units derived from bisphenol A and polycarbonate units derived from poly-n-propylene glycol.

(In formula (1), _Ra to _Rf each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. m, n and l represent integers.)

The polycarbonate copolymer (B) can be produced by conventional production methods such as interfacial polymerization and melt polymerization. For example, it can be produced by reacting at least (B1) bisphenol A and (B2) poly(n-propylene glycol) with a carbonate precursor such as phosgene or diphenyl carbonate.

As the poly-n-propylene glycol (B2) which may have a substituent, various poly-n-propylene glycols can be used. For example, a poly-n-propylene glycol in which a methylene group may have a substituent and is represented by the following general formula (2) is preferably used.

(In formula (2), _Ra to _Rf each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 6 to 600.)

Preferred poly(n-propylene glycol) (B2) are: poly(2-methyl)-n-propylene glycol wherein, in the general formula (2), R _b is a methyl group and _{Ra ,} R _c , R _d , Re and R _f are hydrogen; poly(2-ethyl)-n-propylene glycol wherein R _b is an ethyl group and _Ra , R _c , R _d , _Re and R _f are hydrogen; and poly(2,2-dimethyl)-n-propylene glycol wherein R _b and _Re are methyl groups and _Ra , R _c , R _d and R f are hydrogen. Among these, poly(n-propylene glycol) wherein all of _Ra to R _f are hydrogen atoms (i.e., polytrimethylene glycol) is further preferred.

In this specification, poly(n-propylene glycol) may also be referred to as polytrimethylene glycol, but both have the same meaning and are the same compound.

The poly(n-propylene glycol) (B2) represented by the general formula (2) may be a homopolymer composed of one type of _Ra to _Rf , or may be a copolymer composed of different types of _Ra to _Rf .

Commercially available products of the poly n-propylene glycol (B2) represented by the general formula (2) include poly n-propylene glycol in which R _a to R _f in the general formula (2) are all hydrogen atoms, that is, polytrimethylene glycol, such as "VELVETOL" manufactured by Allessa.

The poly(n-propylene glycol) (B2) represented by the general formula (2) may be a copolymer of a linear polyalkylene glycol such as polyethylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, etc., but polytrimethylene glycol, i.e., a homopolymer of poly(n-propylene glycol), is preferred from the perspective of improving the transparency of the resulting molded article.

The poly-n-propylene glycol (B2) may contain a polyalkylene glycol copolymer having a branched alkylene ether unit (P2) selected from the units represented by the following general formulae (4-1) to (4-4), in addition to the n-propyl ether unit (P1) represented by the following general formula (3).

(In formula (3), _Ra to _Rf have the same meanings as in the above general formula (2).)

(In formulae (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, and in each of formulae (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 units represented by the general formulae (4-1) to (4-4) may be homopolymers composed of branched alkylene ether units having any one structure among the general formulae (4-1) to (4-4), or copolymers composed of branched alkylene ether units having a plurality of structures.

The n-propyl ether unit represented by the general formula (3) is n-propylene glycol when it is expressed as a diol. In addition to n-propylene glycol, ethylene glycol, tetramethylene glycol, pentamethylene glycol, and hexamethylene glycol may be mixed. However, it is preferably only n-propylene glycol, and more preferably only n-propylene glycol (i.e., trimethylene glycol) in which all of R _a to R _f are hydrogen atoms.

Trimethylene glycol can be produced industrially by the following methods: a method of hydrogenating 3-hydroxypropionaldehyde obtained by hydroformylation of ethylene oxide, or a method of hydrogenating 3-hydroxypropionaldehyde obtained by hydrating acrolein using a Ni catalyst. In addition, recently, trimethylene glycol has been produced by reducing glycerol, glucose, starch, etc. to microorganisms using biological methods.

The branched alkylene ether unit represented by the general formula (4-1) may be (2-methyl)ethylene glycol, (2-ethyl)ethylene glycol, (2,2-dimethyl)ethylene glycol, etc. when expressed as a diol. These may be mixed, and (2-methyl)ethylene glycol and (2-ethyl)ethylene glycol are preferred.

When the branched alkylene ether unit represented by the general formula (4-2) is expressed as a diol, examples thereof include (2-methyl)trimethylene glycol, (3-methyl)trimethylene glycol, (2-ethyl)trimethylene glycol, (3-ethyl)triethylene glycol, (2,2-dimethyl)trimethylene glycol (i.e., neopentyl glycol), (2,2-methylethyl)trimethylene glycol, (2,2-diethyl)trimethylene glycol, (3,3-dimethyl)trimethylene glycol, (3,3-methylethyl)trimethylene glycol, and (3,3-diethyl)trimethylene glycol, and these may be mixed.

The branched alkylene ether unit represented by the general formula (4-3) may be exemplified as a diol, and examples thereof 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, (4,4-methylethyl)tetramethylene glycol, and (4,4-diethyl)tetramethylene glycol. These may be mixed, and (3-methyl)tetramethylene glycol is preferred.

When the branched alkylene ether unit represented by the general formula (4-4) is expressed as a diol, examples thereof include (3-methyl)pentamethylene glycol, (4-methyl)pentamethylene glycol, (5-methyl)pentamethylene glycol, (3-ethyl)pentamethylene glycol, (4-ethyl)pentamethylene glycol, (5-ethyl)pentamethylene glycol, (3,3-dimethyl)pentamethylene glycol, (3,3-methylethyl)pentamethylene glycol, (3,3-diethyl)pentamethylene glycol, (4,4-dimethyl)pentamethylene glycol, (4,4-methylethyl)pentamethylene glycol, (4,4-diethyl)pentamethylene glycol, (5,5-dimethyl)pentamethylene glycol, (5,5-methylethyl)pentamethylene glycol, and (5,5-diethyl)pentamethylene glycol, and these may be mixed.

For the sake of convenience, the units represented by the general formulae (4-1) to (4-4) constituting the branched alkylene ether units are described above by taking diols as examples, but the units are not limited to these diols and may be these alkylene oxides or these polyether-forming derivatives.

Preferred poly-n-propylene glycol copolymers (B2) are copolymers composed of n-propyl ether units and units represented by the above general formula (4-2). In particular, copolymers composed of trimethylene ether units and 3-methyltrimethylene ether units are more preferred.

The poly(n-propylene glycol) copolymer (B2) may be a random copolymer or a block copolymer.

The copolymerization ratio of the n-propyl ether unit (P1) represented by the aforementioned general formula (3) and the branched alkylene ether unit (P2) represented by the aforementioned general formulas (4-1) to (4-4) in the poly(n-propylene glycol) copolymer (B2) is preferably 95/5 to 5/95 in terms of the molar ratio (P1)/(P2), more preferably 93/7 to 40/60, further preferably 90/10 to 65/35, and more preferably rich in the n-propyl ether unit (P1).

The molar fraction can be measured using a ¹ H-NMR measuring apparatus with deuterated chloroform as a solvent.

Among the above, the particularly preferred poly n-propylene glycol (B2) is a homopolymer of n-propylene glycol having no substituent, that is, trimethylene glycol.

The polypropylene glycol (B2) may include a structure derived from a polyol such as 1,4-butanediol, glycerol, sorbitol, benzene glycol, bisphenol A, cyclohexanediol, spiroglycol, etc. By adding these polyols during the polymerization of the polyalkylene glycol, these organic groups can be imparted to the main chain. Glycerol, sorbitol, bisphenol A, etc. are particularly preferred.

Preferred examples of polypropylene glycol having an organic group in its structure include:

Polypropylene glycol glycerol ether,

Poly(2-methyl)propylene glycol glycerol ether,

Polypropylene glycol-poly (2-methyl) propanediol glycerol ether,

Polypropylene glycol-poly (2-ethyl) polypropylene glycol glycerol ether,

Polypropylene glycol sorbitan ether,

Poly(2-methyl)propylene glycol sorbitol ether,

Polypropylene glycol-poly (2-methyl) glycol sorbitol ether,

Bisphenol A-bis(polypropylene glycol) ether,

Bisphenol A-bis(poly(2-methyl)propylene glycol) ether, bisphenol A-bis(poly(2-methyl)ethylene glycol) ether,

Bisphenol A-bis(poly-n-propylene glycol-poly(2-ethyl)poly-n-propylene glycol) ether, etc.

The weight average molecular weight (Mw) of polypropylene glycol (B2) is preferably 600 to 8000, more preferably 800 or more, further preferably 1000 or more, more preferably 6000 or less, further preferably 5000 or less, and particularly preferably 4000 or less. When the weight average molecular weight exceeds the upper limit, the compatibility tends to decrease. When the weight average molecular weight exceeds the lower limit, the impact resistance of the composition decreases.

The weight average molecular weight (Mw) is a polystyrene-equivalent molecular weight measured by gel permeation chromatography (GPC) using chloroform as a developing solvent.

Specifically, as GPC, a high-speed GPC apparatus "HLC-8320" manufactured by Tosoh Corporation was used, columns: 3 HZ-M (4.6 mm x 150 mm) manufactured by Tosoh Corporation connected in series, eluent: chloroform, and the value was determined as a polystyrene-equivalent molecular weight (weight average molecular weight).

Examples of carbonate precursors used as monomers of the polycarbonate copolymer (B) include carboxylic acid halides, carbonate esters, etc. The carbonate precursor may be used alone or in any combination and ratio.

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

Specific examples of carbonates include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; dicarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, carbonates of dihydroxy compounds such as cyclic carbonates, etc.

As the polycarbonate copolymer (B), a bisphenol A-poly-n-propylene glycol copolymer polycarbonate represented by the following formula (5) is particularly preferred.

[In formula (5), m, n, and l represent integers.]

The manufacturing method of polycarbonate copolymer (B) is not particularly limited, and known arbitrary methods can be adopted. If its example is enumerated, the ring-opening polymerization method of interfacial polymerization, melt transesterification, pyridine method, cyclic carbonate compound, solid phase transesterification of prepolymer etc. can be enumerated. Among these, preferred melt transesterification, interfacial polymerization, more preferably melt transesterification.

The weight average molecular weight (Mw) of the polycarbonate copolymer (B) is preferably 5,000 to 40,000, more preferably 6,000 or more, further preferably 7,000 or more, more preferably 37,000 or less, further preferably 35,000 or less, particularly preferably 30,000 or less, and most preferably 25,000 or less. When the weight average molecular weight (Mw) exceeds the upper limit, the compatibility tends to decrease. When the weight average molecular weight exceeds the lower limit, gas tends to be generated during molding.

The weight average molecular weight (Mw) of the polycarbonate copolymer (B) can be adjusted by the following methods: selecting the Mw of (B2) polypropylene glycol as one of the comonomer diol raw materials; adjusting the ratio of carbonate precursors, adding terminators, adjusting the temperature and pressure during polymerization, etc. For example, in order to increase the Mw in the melt ester exchange method, it can be adjusted by the following methods: adjusting the monomer raw material ratio so that the reaction ratio of diphenyl carbonate as a carbonate precursor monomer and the diol monomer is close to 1; in order to easily remove the by-product phenol from the polymerization system, the polymerization temperature is kept high, the pressure is reduced as much as possible, and the interface renewal based on stirring is actively carried out.

In addition, the weight average molecular weight (Mw) of the polycarbonate copolymer (B) is a polystyrene conversion molecular weight measured by GPC using chloroform as a developing solvent.

Specifically, as GPC, a high-speed GPC apparatus "HLC-8320" manufactured by Tosoh Corporation was used, columns: manufactured by Tosoh Corporation, HZ-M (4.6 mm×150 mm)×3 columns connected in series, eluent: chloroform, measurement temperature: 25°C, and the value was determined as a polystyrene-equivalent molecular weight (weight average molecular weight).

The content of the polycarbonate copolymer (B) in the polycarbonate resin composition of the present invention is 0.1 to 10 parts by mass, preferably 0.15 parts by mass or more, more preferably 0.2 parts by mass or more, preferably 7 parts by mass or less, more preferably 5 parts by mass or less, further preferably 3 parts by mass or less, particularly 2 parts by mass or less, and most preferably 1 part by mass or less, relative to 100 parts by mass of the polycarbonate resin (A). When the content of the polycarbonate copolymer (B) is less than 0.1 parts by mass within the aforementioned range, the hue and heat discoloration resistance become insufficient, and when it exceeds 10 parts by mass, the material becomes turbid and loses transparency.

[Polycarbonate resin (A)]

The polycarbonate resin (A) used in the present invention is not particularly limited as long as it is other than the above-mentioned polycarbonate copolymer (B), and various types can be used.

Polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbon directly bonded to the carbonic acid bond is aromatic carbon, and aliphatic polycarbonate resins in which the carbon directly bonded to the carbonic acid bond is aliphatic carbon, and both can be used. Among them, as the polycarbonate resin (A), aromatic polycarbonate resins are preferred from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

Examples of aromatic dihydroxy compounds among monomers used as raw materials of aromatic polycarbonate resins include:

Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene;

Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2’-dihydroxybiphenyl, and 4,4’-dihydroxybiphenyl;

Dihydroxynaphthalenes such as 2,2'-dihydroxy-1,1'-binaphthalene, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;

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

2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A),

1,1-bis(4-hydroxyphenyl)propane,

2,2-Bis(3-methyl-4-hydroxyphenyl)propane,

2,2-Bis(3-methoxy-4-hydroxyphenyl)propane,

2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane,

1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane,

2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane,

2,2-Bis(3-cyclohexyl-4-hydroxyphenyl)propane,

2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane,

α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene,

1,3-Bis[2-(4-hydroxyphenyl)-2-propyl]benzene,

Bis(4-hydroxyphenyl)methane,

Bis(4-hydroxyphenyl)cyclohexylmethane,

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,

etc. bis(hydroxyaryl)alkanes;

1,1-Bis(4-hydroxyphenyl)cyclopentane,

1,1-bis(4-hydroxyphenyl)cyclohexane,

1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane,

1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane,

1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane,

1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,

1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane,

1,1-bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane,

1,1-bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane,

1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane,

1,1-Bis(4-hydroxyphenyl)-4-phenylcyclohexane,

etc. bis(hydroxyaryl)cycloalkanes;

9,9-bis(4-hydroxyphenyl)fluorene,

Bisphenols containing a cardo structure such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

4,4'-Dihydroxydiphenyl sulfide,

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

Dihydroxy diaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;

4,4'-Dihydroxydiphenyl sulfone,

Dihydroxydiaryl sulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone;

wait.

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

In addition, the aromatic dihydroxy compound may be used alone or in combination of two or more in any combination and ratio.

Among monomers used as raw materials of the polycarbonate resin, examples of carbonate precursors include carboxylic acid halides, carbonate esters, etc. The carbonate precursor may be used alone or in any combination and ratio.

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

Specific examples of carbonates include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; dicarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, carbonates of dihydroxy compounds such as cyclic carbonates, etc.

The manufacturing method of polycarbonate resin (A) is not particularly limited, and any method can be adopted. If its example is enumerated, the ring-opening polymerization method of interfacial polymerization, melt transesterification, pyridine method, cyclic carbonate compound, solid phase transesterification of prepolymer etc. can be enumerated. Among these, also particularly preferably by interfacial polymerization.

The molecular weight of the polycarbonate resin (A) is a viscosity average molecular weight (Mv) calculated from the solution viscosity measured at 25° C. using dichloromethane as a solvent, and is preferably 10,000 to 26,000, more preferably 10,500 or more, further preferably 11,000 or more, particularly 11,500 or more, most preferably 12,000 or more, more preferably 24,000 or less, and further preferably 20,000 or less. By setting the viscosity average molecular weight to be equal to or greater than the lower limit of the above range, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, and by setting the viscosity average molecular weight to be equal to or less than the upper limit of the above range, the decrease in fluidity of the polycarbonate resin composition of the present invention can be suppressed and improved, and the moldability can be improved to facilitate thin-wall molding.

It should be noted that two or more polycarbonate resins having different viscosity average molecular weights may be mixed and used. In this case, a polycarbonate resin having a viscosity average molecular weight not falling within the above-described preferred range may be mixed.

It should be noted that the viscosity average molecular weight [Mv] refers to a value calculated from the Schnell viscosity formula, i.e., η=1.23×10 ^-4 Mv ^0.83 , by using methylene chloride as a solvent and an Ubbelohde viscometer to determine the intrinsic viscosity [η] (unit: dl/g) at a temperature of 25°C. In addition, the intrinsic viscosity [η] is a value calculated from the specific viscosity [η _sp ] measured at each solution concentration [C] (g/dl) and calculated according to the following formula.

The terminal hydroxyl concentration of polycarbonate resin (A) is arbitrary, can be suitably selected and determined, is usually below 1000ppm, preferably below 800ppm, more preferably below 600ppm.Thus, the retention thermal stability and the hue of polycarbonate resin can be further improved.In addition, particularly for the polycarbonate resin manufactured by melt transesterification, its lower limit is usually more than 10ppm, preferably more than 30ppm, more preferably more than 40ppm.Thus, the reduction of molecular weight can be suppressed, and the mechanical properties of resin combination can be further improved.

The unit of the terminal hydroxyl group concentration is ppm, which represents the mass of the terminal hydroxyl group relative to the mass of the polycarbonate resin. The determination method is a colorimetric quantitative method based on the titanium tetrachloride/acetic acid method (the method described in Macromol. Chem. 88 215 (1965)).

In addition, in order to improve the appearance and fluidity of the molded article, the polycarbonate resin (A) may also contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of the polycarbonate oligomer is usually 1500 or more, preferably 2000 or more, and usually 9500 or less, preferably 9000 or less. Furthermore, the polycarbonate oligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Furthermore, the polycarbonate resin (A) may be not only a pure raw material but also a polycarbonate resin recycled from a used product (so-called recycled polycarbonate resin).

However, the recycled polycarbonate resin is preferably 80% by mass or less, more preferably 50% by mass or less, of the polycarbonate resin (A). This is because the recycled polycarbonate resin is highly likely to be degraded by heat degradation, deterioration over time, etc., and therefore, if such a polycarbonate resin is used in an amount exceeding the above range, the color and mechanical properties may be reduced.

[Phosphorus stabilizer (C)]

The polycarbonate resin composition of the present invention contains a phosphorus-based stabilizer (C). By containing the phosphorus-based stabilizer, the hue of the polycarbonate resin composition of the present invention becomes good, and the heat discoloration resistance is improved.

As the phosphorus stabilizer, any known substance can be used. Specific examples include phosphorus oxygen acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; phosphate compounds, phosphite compounds, and phosphonite compounds, and phosphite compounds are particularly preferred. By selecting phosphite compounds, a polycarbonate resin composition with higher color resistance and continuous productivity can be obtained.

Here, the phosphite compound is a trivalent phosphorus compound represented by the general formula: P(OR) ₃ , wherein R represents a monovalent or divalent organic group.

Examples of such phosphite compounds include triphenyl phosphite, tris(mononylphenyl) phosphite, tris(mononyl/dinonyl/phenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, bis ... and bis(2,4-di-tert-butylphenyl) phosphite. di-tert-butyl-4-methylphenyl) pentaerythritol phosphite, bis(2,6-di-tert-butylphenyl) octyl phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-diphosphite, 6-[3-(3-tert-butyl-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]-dioxaphosphite, etc.

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

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

[In formula (2), ^R4 and ^R5 may be the same or different and represent an aryl group having 6 or more and 30 or less carbon atoms.]

As the phosphite compound represented by the above formula (1), triphenyl phosphite, tris(mononylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, etc. are preferred, and tris(2,4-di-tert-butylphenyl) phosphite is more preferred. As such an organic phosphite compound, specifically, for example, "Adekastab 1178" manufactured by ADEKA Corporation, "Sumilizer TNP" manufactured by Sumitomo Chemical Co., Ltd., "JP-351" manufactured by Johoku Chemical Industry Co., Ltd., "Adekastab 2112" manufactured by ADEKA Corporation, "Irgafos 168" manufactured by BASF Corporation, "JP-650" manufactured by Johoku Chemical Industry Co., Ltd., etc. can be cited.

As the phosphite compound represented by the above formula (2), particularly preferred are those having a pentaerythritol diphosphite structure such as bis(2,4-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite. As such an organic phosphite compound, specifically, for example, "Adekastab PEP-24G" and "Adekastab PEP-36" manufactured by ADEKA Corporation, and "Doverphos S-9228" manufactured by Doverchemical Co., Ltd. can be preferably cited.

Among the phosphite compounds, the aromatic phosphite compounds represented by the above formula (2) are more preferred because of their excellent hue.

The phosphorus-based stabilizer may be contained alone or in combination of two or more in any ratio.

The content of the phosphorus stabilizer (C) is 0.005 to 0.5 parts by mass relative to 100 parts by mass of the polycarbonate resin (A), preferably 0.007 parts by mass or more, more preferably 0.008 parts by mass or more, particularly preferably 0.01 parts by mass or more, and preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, further preferably 0.2 parts by mass or less, and particularly preferably 0.1 parts by mass or less. When the content of the phosphorus stabilizer (C) is less than 0.005 parts by mass in the aforementioned range, the hue and heat discoloration resistance become insufficient, and when the content of the phosphorus stabilizer (C) exceeds 0.5 parts by mass, not only the heat discoloration resistance is deteriorated, but also the wet heat stability is reduced.

[Epoxy compound and/or oxetane compound (D)]

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

As the epoxy compound, a compound having one or more epoxy groups in one molecule is used. Specifically, preferably phenyl glycidyl ether, allyl glycidyl ether, tert-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy-6'-methylcyclohexylcarboxylate, 2,3-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate, 4-(3,4-epoxy-5-methylcyclohexyl)butyl-3',4'-epoxycyclohexylcarboxylate, 3,4-epoxy- Cyclohexylethylene oxide, cyclohexyl methyl 3,4-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexyl methyl-6'-methylcyclohexyl carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene glycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxy phthalate, epoxidized Polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1,2-epoxycyclohexane, 3-methyl-5-tert-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate, N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate, N-butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexyl carboxylate, octadecyl-3,4- Epoxycyclohexylcarboxylate, 2-ethylhexyl-3',4'-epoxycyclohexylcarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3',4'-epoxycyclohexylcarboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3-tert-butyl-4,5-epoxytetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, di-n-butyl-3-tert-butyl-4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, epoxidized soybean oil, epoxidized linseed oil, etc.

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

In addition, a polyalkylene glycol derivative having an epoxy group at one or both ends can also be preferably used. In particular, a polyalkylene glycol having an epoxy group at both ends is preferred.

Preferred examples of the polyalkylene glycol derivative having an epoxy group in the structure 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, and polytetramethylene glycol-poly(2-ethyl)ethylene glycol diglycidyl ether.

The epoxy compounds may be used alone or in combination of two or more.

The preferred content of the epoxy compound is 0.0005 to 0.2 parts by mass relative to 100 parts by mass of the polycarbonate resin (A), more preferably 0.001 parts by mass or more, further preferably 0.003 parts by mass or more, particularly preferably 0.005 parts by mass or more, and more preferably 0.15 parts by mass or less, further preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less. When the content of the epoxy compound is less than 0.0005 parts by mass, the hue and heat discoloration resistance are likely to become insufficient, and when it exceeds 0.2 parts by mass, the heat discoloration resistance is likely to deteriorate, and the hue and wet heat stability are also likely to decrease.

As the oxetane compound, any compound having one or more oxetane groups in the molecule can be used, and both a monooxetane compound having one oxetane group in the molecule and a difunctional or higher polyoxetane compound having two or more oxetane groups in the molecule can be used.

By containing an oxetane compound, the good hue and high heat discoloration resistance can be further improved.

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

[In formulae (3) to (5), ^R1 represents an alkyl group, ^R2 represents an alkyl group or a phenyl group, ^R3 represents a divalent organic group which may have an aromatic ring, and n represents 0 or 1.]

In the above general formulae (3), (4) and (5), ^R1 is an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, preferably a methyl group or an ethyl group, and particularly preferably an ethyl group.

In addition, ^R2 is an alkyl group or a phenyl group, preferably an alkyl group having 2 to 10 carbon atoms, and may be any of a chain alkyl group, a branched alkyl group or an alicyclic alkyl group, or may be a chain or branched alkyl group having an ether bond (ether oxygen atom) in the middle of the alkyl chain. Specific examples of ^R2 include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, 3-oxopentyl, cyclohexyl, and phenyl. Among them, ^R2 is preferably 2-ethylhexyl, phenyl, and cyclohexyl.

Specific examples of the compound of general formula (3) include preferably 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxymethyl-3-n-butyloxetane, 3-hydroxymethyl-3-propyloxetane, etc. Among them, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, etc. are particularly preferred.

As specific examples of the compound of the general formula (4), 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane and the like are particularly preferred.

In the general formula (5), ^R3 is a divalent organic group which may have an aromatic ring, and examples thereof include a linear or branched alkylene group having 1 to 12 carbon atoms such as ethylene, propylene, butylene, neopentylene, n-pentylene, and n-hexylene, a phenylene group, a divalent group represented by the formula: _-CH2 -Ph- _CH2- or _-CH2 -Ph-Ph- _CH2- (wherein Ph represents a phenyl group), a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol Z residue, a cyclohexanedimethanol residue, and a tricyclodecane dimethanol residue.

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

The oxetane compound may be used alone or in combination of two or more.

The content of the oxetane compound is preferably 0.0005 to 0.2 parts by mass relative to 100 parts by mass of the polycarbonate resin (A), more preferably 0.001 parts by mass or more, further preferably 0.003 parts by mass or more, particularly preferably 0.005 parts by mass or more, and more preferably 0.15 parts by mass or less, further preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less. When the content of the oxetane compound is less than 0.0005 parts by mass, the hue and heat discoloration resistance are likely to become insufficient, and when it exceeds 0.2 parts by mass, the heat discoloration resistance is easily deteriorated, and gas is easily generated during molding.

It is also preferred that both the epoxy compound and the oxetane compound be contained in combination. When both are contained, the total content is preferably 0.0005 to 0.2 parts by mass based on 100 parts by mass of the polycarbonate resin (A).

[Polyalkylene glycol]

The resin composition of the present invention also preferably contains a polyalkylene glycol.

Preferred examples of the polyalkylene glycol compound include polyalkylene glycol copolymers (CP) having a linear alkylene ether unit (P1) represented by the following general formula (2) and a branched alkylene ether unit (P2) selected from units represented by the following general formulas (2A) to (2D).

In the general formula (2), t represents an integer of 3-6.

In the general formulae (2A) to (2D), R ³¹ to R ⁴⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. At least one of R ³¹ to R ⁴⁰ in the general formulae (2A) to (2D) is an alkyl group having 1 to 3 carbon atoms.

As the linear alkylene ether unit (P1) represented by the general formula (2), when it is expressed as a diol, examples thereof include trimethylene glycol where t is 3, tetramethylene glycol where t is 4, pentamethylene glycol where t is 5, and hexamethylene glycol where t is 6. Preferred are trimethylene glycol and tetramethylene glycol, and particularly preferred is tetramethylene glycol.

Trimethylene glycol (i.e., n-propylene glycol) can be produced industrially by hydrogenating 3-hydroxypropionaldehyde obtained by hydroformylation of ethylene oxide, or by hydrogenating 3-hydroxypropionaldehyde obtained by hydrogenating acrolein using a Ni catalyst. Trimethylene glycol can also be produced by biological methods by reducing glycerol, glucose, starch, etc. to microorganisms.

When the branched alkylene ether unit represented by the general formula (2A) is expressed as a diol, examples thereof include (2-methyl)ethylene glycol (i.e., propylene glycol), (2-ethyl)ethylene glycol (i.e., butanediol), and (2,2-dimethyl)ethylene glycol (i.e., neopentyl glycol).

The branched alkylene ether unit represented by the general formula (2B) may be exemplified in the case of a diol, 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, and (3,3-diethyl)trimethylene glycol.

The branched alkylene ether unit represented by the general formula (2C) may be exemplified in the case of a diol, such as (3-methyl)tetramethylene glycol, (4-methyl)tetramethylene glycol, (3-ethyl)tetramethylene glycol, (4-ethyl)tetramethylene glycol, (3,3-dimethyl)tetramethylene glycol, (3,3-methylethyl)tetramethylene glycol, (3,3-diethyl)tetramethylene glycol, (4,4-dimethyl)tetramethylene glycol, (4,4-methylethyl)tetramethylene glycol, and (4,4-diethyl)tetramethylene glycol, and (3-methyl)tetramethylene glycol is preferred.

Examples of the branched alkylene ether unit represented by the general formula (2D) include (3-methyl)pentamethylene glycol, (4-methyl)pentamethylene glycol, (5-methyl)pentamethylene glycol, (3-ethyl)pentamethylene glycol, (4-ethyl)pentamethylene glycol, (5-ethyl)pentamethylene glycol, (3,3-dimethyl)pentamethylene glycol, (3,3-methylethyl)pentamethylene glycol, (3,3-diethyl)pentamethylene glycol, (4,4-dimethyl)pentamethylene glycol, (4,4-methylethyl)pentamethylene glycol, (4,4-diethyl)pentamethylene glycol, (5,5-dimethyl)pentamethylene glycol, (5,5-methylethyl)pentamethylene glycol, and (5,5-diethyl)pentamethylene glycol.

For convenience, diols are used as an example to describe the units represented by the general formulas (2A) to (2D) constituting the branched alkylene ether units (P2). However, the units are not limited to these diols and may be these alkylene oxides or these polyether derivatives.

Preferred polyalkylene glycol copolymers (CP) include copolymers composed of tetramethylene ether (i.e., tetramethylene glycol) units and units represented by the general formula (2A), and copolymers composed of tetramethylene ether (i.e., tetramethylene glycol) units and 2-methylethyl ether (i.e., propylene glycol) units and/or (2-ethyl)ethylene glycol (i.e., butylene glycol) units are particularly preferred. Copolymers composed of tetramethylene ether units and 2,2-dimethyltrimethylene ether units, i.e., neopentyl glycol ether units, are also preferred.

The method for producing a polyalkylene glycol copolymer (CP) having a linear alkylene ether unit (P1) and a branched alkylene ether unit (P2) is well known, and it can be produced by polycondensing the above-mentioned diol, alkylene oxide or a polyether derivative thereof using a common acid catalyst.

The polyalkylene glycol copolymer (CP) may be a random copolymer or a block copolymer.

The terminal groups of the polyalkylene glycol copolymer (CP) are preferably hydroxyl groups. Even if one or both ends of the polyalkylene glycol copolymer (CP) are capped with alkyl ethers, aryl ethers, arylalkyl ethers, fatty acid esters, aryl esters, etc., it does not affect the performance, and etherified or esterified products can be used in the same manner.

The alkyl group constituting the alkyl ether may be any of a linear or branched chain, and examples thereof include alkyl groups having 1 to 22 carbon atoms, such as methyl, ethyl, propyl, butyl, octyl, lauryl, and stearyl groups. Preferred examples of the alkyl ether include methyl ether, ethyl ether, butyl ether, lauryl ether, and stearyl ether of polyalkylene glycol.

The aryl group constituting the aryl ether is preferably an aryl group having 6 to 22 carbon atoms, more preferably 6 to 12 carbon atoms, and further preferably 6 to 10 carbon atoms, and examples thereof include phenyl, tolyl, and naphthyl, and preferably phenyl, tolyl, and the like. The aralkyl group is preferably an aralkyl group having 7 to 23 carbon atoms, more preferably 7 to 13 carbon atoms, and further preferably 7 to 11 carbon atoms, and examples thereof include benzyl, phenethyl, and the like, and particularly preferably benzyl.

The fatty acid constituting the fatty acid ester may be linear or branched, and may be a saturated fatty acid or an unsaturated fatty acid.

As fatty acids constituting fatty acid esters, monovalent or divalent fatty acids having 1 to 22 carbon atoms can be cited. As monovalent saturated fatty acids, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, capric acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid can be cited. As monovalent unsaturated fatty acids, for example, unsaturated fatty acids such as oleic acid, elaidic acid, linoleic acid, linolenic acid, and arachidonic acid can be cited. As divalent fatty acids having more than 10 carbon atoms, for example, sebacic acid, undecane dioic acid, dodecanedioic acid, tetradecanedioic acid, tauric acid, and decadecenedioic acid, undecenedioic acid, and dodecanedioic acid can be cited.

The aryl group constituting the aryl ester is preferably an aryl group having 6 to 22 carbon atoms, more preferably 6 to 12 carbon atoms, and further preferably 6 to 10 carbon atoms, and examples thereof include phenyl, tolyl, naphthyl, and the like, and preferably phenyl, tolyl, and the like. The end-capping group is an aralkyl group and exhibits good compatibility with the polycarbonate resin (A), and thus can play the same role as the aryl group. The aralkyl group is preferably an aralkyl group having 7 to 23 carbon atoms, more preferably 7 to 13 carbon atoms, and further preferably 7 to 11 carbon atoms, and examples thereof include benzyl, phenethyl, and the like, and particularly preferably benzyl.

As the polyalkylene glycol copolymer (CP), among them, a copolymer composed of a tetramethylene ether unit and a 2-methyl ethyl ether unit, a copolymer composed of a tetramethylene ether unit and a 3-methyltetramethylene ether unit, and a copolymer composed of a tetramethylene ether unit and a 2,2-dimethyltrimethylene ether unit are particularly preferred. Commercially available products of such polyalkylene glycol copolymers include "Polystyrene DCB" manufactured by NOF Corporation, "PTG-L" manufactured by Hodogaya Chemical Co., Ltd., and "PTXG" manufactured by Asahi Kasei Fibers Co., Ltd.

The copolymer composed of a tetramethylene ether unit and a 2,2-dimethyltrimethylene ether unit can also be produced by the method described in JP-A-2016-125038.

As the polyalkylene glycol compound, a branched polyalkylene glycol compound represented by the following general formula (3A) or a linear polyalkylene glycol compound represented by the following general formula (3B) can also be listed as a preferred example. The branched polyalkylene glycol compound represented by the following general formula (3A) or the linear polyalkylene glycol compound represented by the following general formula (3B) can be a copolymer of other copolymer components, preferably a homopolymer.

In the general formula (3A), R represents an alkyl group having 1 to 3 carbon atoms. ^Q1 and ^Q2 each independently represent a hydrogen atom, an aliphatic acyl group having 1 to 23 carbon atoms, or an alkyl group having 1 to 23 carbon atoms. r represents an integer of 5 to 400.

In the general formula (3B), ^Q3 and ^Q4 each independently represent a hydrogen atom, an aliphatic acyl group having 2 to 23 carbon atoms, or an alkyl group having 1 to 23 carbon atoms. p represents an integer of 2 to 6, and q represents an integer of 6 to 100.

In the general formula (3A), the integer (polymerization degree) r is 5 to 400, preferably 10 to 200, more preferably 15 to 100, and particularly preferably 20 to 50. When the polymerization degree r is less than 5, the amount of gas generated during molding increases, and molding errors due to gas, such as non-filling, gas combustion, and transfer errors, may occur. When the polymerization degree r exceeds 400, there is a concern that the effect of improving the color of the pellets of the present invention cannot be fully obtained.

As the branched polyalkylene glycol compound, in the general formula (3A), preferred are polypropylene glycol (i.e., poly(2-methyl)ethylene glycol) in which Q ¹ and Q ² are hydrogen atoms and R is a methyl group, and polybutylene glycol (i.e., poly(2-ethyl)ethylene glycol) in which R is an ethyl group. Polybutylene glycol (i.e., poly(2-ethyl)ethylene glycol) is particularly preferred.

In the general formula (3B), q (polymerization degree) is an integer of 6 to 100, preferably 8 to 90, more preferably 10 to 80. When the polymerization degree q is less than 6, gas is generated during molding, which is not preferred. When the polymerization degree q exceeds 100, compatibility decreases, which is not preferred.

As the straight-chain polyalkylene glycol compound, preferably listed are polyethylene glycol wherein ^Q3 and ^Q4 in the general formula (3B) are hydrogen atoms, p is 2, polytrimethylene glycol wherein p is 3, polytetramethylene glycol wherein p is 4, polypentamethylene glycol wherein p is 5, and polyhexamethylene glycol wherein p is 6. More preferred are polytrimethylene glycol, polytetramethylene glycol, or esters or ethers thereof.

As a polyalkylene glycol compound, even if one or both ends are blocked with fatty acid or alcohol, it will not affect its performance and can be used in the same way as fatty acid esters or ethers. Therefore, ^Q1 to ^Q4 in the general formula (3A) and (3B) can also be aliphatic acyl or alkyl groups having 1 to 23 carbon atoms.

As the fatty acid ester, any of straight-chain or branched fatty acid esters can be used. The fatty acid constituting the fatty acid ester can be a saturated fatty acid or an unsaturated fatty acid. A part of the hydrogen atoms can also be substituted by a substituent such as a hydroxyl group.

As the fatty acid constituting the fatty acid ester, monovalent or divalent fatty acids having 1 to 23 carbon atoms can be listed. As monovalent saturated fatty acids, specifically, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, capric acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid can be listed. As monovalent unsaturated fatty acids, specifically, unsaturated fatty acids such as oleic acid, elaidic acid, linoleic acid, linolenic acid, and arachidonic acid can be listed. As divalent fatty acids having more than 10 carbon atoms, specifically, sebacic acid, undecane dioic acid, dodecanedioic acid, tetradecanedioic acid, tauric acid, and decadecenedioic acid, undecenedioic acid, and dodecanedioic acid can be listed.

The fatty acid may be used alone or in combination of two or more. The fatty acid also includes a fatty acid having one or more hydroxyl groups in the molecule.

Preferred specific examples of branched polyalkylene glycol fatty acid esters include polypropylene glycol stearate wherein R is a methyl group, ^Q1 and ^Q2 are aliphatic acyl groups having 18 carbon atoms, and polypropylene glycol behenate wherein R is a methyl group, and ^Q1 and ^Q2 are aliphatic acyl groups having 22 carbon atoms. Preferred specific examples of linear polyalkylene glycol fatty acid esters include polyalkylene glycol monopalmitate, polyalkylene glycol dipalmitate, polyalkylene glycol monostearate, polyalkylene glycol distearate, polyalkylene glycol (monopalmitate/monostearate) esters, and polyalkylene glycol behenate.

The alkyl group constituting the alkyl ether of the polyalkylene glycol may be any of a linear or branched chain, and examples thereof include alkyl groups having 1 to 23 carbon atoms, such as methyl, ethyl, propyl, butyl, octyl, lauryl, and stearyl. Preferred examples of the polyalkylene glycol compound include alkyl methyl ether, ethyl ether, butyl ether, lauryl ether, and stearyl ether of polyalkylene glycol.

Commercially available products of the branched polyalkylene glycol compound represented by the general formula (3A) include "UNIOL D-1000" and "UNIOL PB-1000" manufactured by NOF Corporation.

The number average molecular weight of polyalkylene glycol compounds such as polyalkylene glycol copolymers (CP), branched polyalkylene glycol compounds represented by general formula (3A), and linear polyalkylene glycol compounds represented by general formula (3B) is preferably 200 to 5000, more preferably 300 or more, further preferably 500 or more, more preferably 4000 or less, further preferably 3000 or less, particularly preferably 2000 or less, particularly preferably less than 1000, and most preferably 800 or less. When the number average molecular weight exceeds the upper limit, there is a tendency for compatibility to decrease. When the number average molecular weight exceeds the lower limit, there is a tendency for gas to be generated during molding. The number average molecular weight of the polyalkylene glycol compound is a number average molecular weight calculated based on the hydroxyl value measured in accordance with JIS K1577.

These polyalkylene glycol compounds may be used alone or in combination of two or more.

When the resin composition of the present invention contains a polyalkylene glycol compound, its content is preferably 0.001 to 1.0 parts by mass, more preferably 0.01 to 0.8 parts by mass, and particularly preferably 0.1 to 0.5 parts by mass relative to 100 parts by mass of the polycarbonate resin (A). If the content of the polyalkylene glycol compound is less than the above lower limit or exceeds the above upper limit, the color of the obtained molded product tends to be different.

[Release agent]

The resin composition of the present invention also preferably contains a release agent.

Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils.

As aliphatic carboxylic acids, for example, saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acids can be listed. Here, aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and more preferably aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms. Specific examples of the above-mentioned aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetratriacontanoic acid, montanic acid, adipic acid, azelaic acid, etc.

As the aliphatic carboxylic acid in the ester of aliphatic carboxylic acid and alcohol, for example, the same as the above-mentioned aliphatic carboxylic acid can be used. On the other hand, as alcohol, for example, saturated or unsaturated monohydric alcohol or polyhydric alcohol can be listed. These alcohols may have substituents such as fluorine atoms and aromatic groups. Among these, monohydric or polyhydric saturated alcohols with a carbon number of less than 30 are preferred, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols with a carbon number of less than 30 are further preferred. It should be noted that aliphatic is used here as a term including alicyclic compounds.

Specific examples of the alcohol include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentyl glycol, di(trimethylol)propane, and dipentaerythritol.

It should be noted that the above-mentioned ester may contain aliphatic carboxylic acid and/or alcohol as impurities. In addition, the above-mentioned ester may be a pure substance or a mixture of multiple compounds. Furthermore, the aliphatic carboxylic acid and alcohol that combine to form an ester may be used in one kind each, or in combination of two or more kinds in any combination and ratio.

Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture containing beeswax palmitate as the main component), stearyl stearate, behenyl behenate, stearyl behenate, glyceryl monopalmitate, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, and the like.

Examples of aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microcrystalline wax, polyethylene wax, Fischer Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. It should be noted that the aliphatic hydrocarbons herein also include alicyclic hydrocarbons. In addition, these hydrocarbons may be partially oxidized.

Among these, paraffin wax, polyethylene wax or a partial oxide of polyethylene wax is preferred, and paraffin wax and polyethylene wax are more preferred.

Furthermore, the number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.

It should be noted that the aliphatic hydrocarbon may be a single substance or a mixture having different constituent components and molecular weights, and any aliphatic hydrocarbon may be used as long as the main component is within the above-mentioned range.

Examples of the polysiloxane-based silicone oil include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

In addition, the said mold release agent may contain 1 type, and may contain 2 or more types in arbitrary combinations and ratios.

The content of the release agent is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass or less, relative to 100 parts by mass of the polycarbonate resin (A). When the content of the release agent is less than the lower limit of the aforementioned range, the effect of mold release may be insufficient, and when the content of the release agent exceeds the upper limit of the aforementioned range, a decrease in hydrolysis resistance and mold contamination during injection molding may occur.

[Additives, etc.]

The polycarbonate resin composition of the present invention may contain other additives other than those mentioned above, such as antioxidants, ultraviolet absorbers, fluorescent whitening agents, pigments, dyes, other polymers other than polycarbonate resins, flame retardants, impact modifiers, antistatic agents, plasticizers, and compatibilizers. These additives may be mixed alone or in combination of two or more.

Among them, the content of other polymers other than the polycarbonate resin (A) and the polycarbonate copolymer (B) is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, further preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, relative to 100 parts by mass of the total of the polycarbonate resin (A) and the polycarbonate copolymer (B).

[Method for producing polycarbonate resin composition]

There is no limitation on the method for producing the polycarbonate resin composition of the present invention, and a wide range of known methods for producing the polycarbonate resin composition can be used, including the following method: the aromatic polycarbonate resin (A), the polycarbonate copolymer (B) and the phosphorus stabilizer (C), and other components to be blended as required are pre-mixed using various mixers such as a drum mixer and a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, a roll, a Brabender extensometer, a single-screw mixing extruder, a twin-screw mixing extruder, and a kneader. It should be noted that the temperature for melt-kneading is not particularly limited, and is generally in the range of 240 to 320°C.

[Polycarbonate resin composition]

The polycarbonate resin composition of the present invention has excellent hue and therefore excellent YI (yellowing index). The initial YI value at an optical path length of 300 mm is preferably 25 or less. In addition, due to its excellent heat discoloration resistance, the difference (ΔYI) between the YI value at an optical path length of 300 mm after being kept at 95°C for 1000 hours and the initial YI value is preferably 6 or less.

The initial YI value is more preferably 24 or less, further preferably 22 or less, further preferably 20 or less. ΔYI is more preferably 5 or less, further preferably 4 or less.

It should be noted that for the measurement of the initial YI value and ΔYI, a long light path molded product (300mm×7mm×4mm) was molded at a resin temperature of 340°C and a mold temperature of 80°C, and the YI value (initial YI value) was measured under a C light source and a 2° field of view with a light path length of 300 mm. In addition, the YI value after being maintained at 95°C for 1000 hours was measured, and the difference ΔYI with the initial YI value was calculated.

The polycarbonate resin composition of the present invention has excellent impact resistance, and therefore the Charpy notched impact strength of a molded article with a thickness of 3 mm according to ISO 179 is preferably 25 kJ/m ² or more, more preferably 30 kJ/m ² or more, and further preferably 35 kJ/m ² or more.

Furthermore, the present invention can also provide the following polycarbonate resin composition.

That is, a polycarbonate resin composition, characterized in that it contains 0.001 to 0.5 parts by mass of a stabilizer relative to 100 parts by mass of a polycarbonate resin (A), the initial YI value at an optical path length of 300 mm is 25 or less, and the difference (ΔYI) between the YI value at an optical path length of 300 mm after being kept at 95° C. for 1000 hours and the initial YI value is 6 or less.

The initial YI value is preferably 24 or less, more preferably 22 or less, and further preferably 20 or less. ΔYI is preferably 5 or less, and more preferably 4 or less.

The stabilizer in this case is preferably a phosphorus stabilizer. The phosphorus stabilizer is as described above.

The polycarbonate resin composition has a Charpy notched impact strength of a 3 mm thick molded article in accordance with ISO 179 of preferably 25 kJ/m ² or more, more preferably 30 kJ/m ² or more, and even more preferably 35 kJ/m ² or more.

[Optical components]

The polycarbonate resin composition of the present invention can be granulated and the obtained pellets can be molded by various molding methods to produce optical parts. In addition, the resin melt-kneaded in an extruder can be directly molded to form optical parts without pelletizing.

The polycarbonate resin composition of the present invention has excellent fluidity and color, and generates very little gas and mold contamination during molding. Therefore, it is particularly suitable for molding optical parts, especially thin-walled optical parts that are prone to mold contamination, by injection molding. As for the resin temperature during injection molding, especially in the case of thin-walled molded products, it is preferred to mold at a resin temperature higher than 260 to 300°C, which is a temperature generally suitable for injection molding of polycarbonate resins, and preferably a resin temperature of 305 to 400°C. The resin temperature is more preferably 310°C or higher, further preferably 315°C or higher, and particularly preferably 320°C or higher for pellets, and more preferably 390°C or lower. When using the existing polycarbonate resin composition, in order to mold thin-walled molded products, if the resin temperature during molding is increased, there is also a problem that the molded products are prone to yellowing. However, by using the resin composition of the present invention, molded products with good color and high transparency, especially thin-walled optical parts, can be manufactured even in the above temperature range.

In addition, when it is difficult to measure the resin temperature directly, it can be understood as the barrel setting temperature.

Here, the thin-walled molded product generally refers to a molded product having a plate-like portion with a wall thickness of 1 mm or less, preferably 0.8 mm or less, and more preferably 0.6 mm or less. Here, the plate-like portion may be a flat plate, a curved plate, or a flat surface, and the surface may have concave and convex shapes, and the cross section may have an inclined surface or a wedge-shaped cross section.

Optical components include components of equipment/devices that directly or indirectly utilize light sources such as LEDs, organic ELs, incandescent bulbs, fluorescent lamps, and cathode tubes, and light guide plates and components for surface emitters are representative examples.

The light guide plate is a device used to guide light from light sources such as LEDs in liquid crystal backlight units, various display devices, and lighting devices. It diffuses light incident from the side or back through the concave and convex surfaces usually provided on the surface, and emits uniform light. Its shape is usually a flat plate, and it may or may not have concave and convex surfaces.

The light guide plate is usually preferably molded by injection molding, ultra-high-speed injection molding, injection compression molding, melt extrusion molding (for example, T-die molding), or the like.

The light guide plate molded using the resin composition of the present invention has no white turbidity or reduction in transmittance, has good hue and high transparency, and has little molding error due to mold contamination.

The light guide plate using the polycarbonate resin composition of the present invention can be suitably used in the fields of liquid crystal backlight units, various display devices, and lighting devices. Examples of such devices include various mobile terminals such as mobile phones, mobile notebooks, netbooks, tablet personal computers, tablet computers, smart phones, and tablet-type terminals, cameras, clocks, portable computers, various displays, and lighting equipment.

The optical member may be in the form of a film or a sheet, and specific examples thereof include a light guide film.

In addition, as optical components, light guides, lenses, etc. for guiding light from light sources such as LEDs are also suitable in light-guiding components for exterior lighting, such as headlights or taillights, fog lights, etc. for vehicles such as automobiles or motorcycles, and can also be suitably used in these.

The light guide plate using the polycarbonate resin composition of the present invention can be suitably used in the fields of liquid crystal backlight units, various display devices, and lighting devices. Examples of such devices include various portable terminals such as mobile phones, mobile notebooks, netbooks, tablet PCs, tablet PCs, smart phones, and tablet terminals, cameras, clocks, personal computers, various displays, and lighting equipment.

Example

The present invention will be described in more detail below with reference to examples, but the present invention is not to be construed as being limited to the following examples.

The raw materials used in the following examples and comparative examples are shown in Table 1.

[Table 1]

In addition, in the said Table 1, the polycarbonate copolymers (B1) - (B4) and another polycarbonate copolymer (Y1) were manufactured by the following manufacturing examples 1-5.

[Production Example 1 of Polycarbonate Copolymer (B1)]

In a polymerization apparatus equipped with a 1L three-necked flask, 85% by mass of "VELVETOL H500" (Mw: 1700) manufactured by ALLESSA as polypropylene glycol (i.e., polytrimethylene glycol), 15% by mass of bisphenol A, and 1.16 molar ratio of diphenyl carbonate to diol were added. As a catalyst, 11 μmol (in terms of Cs) of Cs ₂ CO ₃ aqueous solution was added per 1 mol of diol. After drying the system for 1 hour, the inside of the polymerization apparatus was re-pressurized with nitrogen. The polymerization was started when the re-pressurized polymerization apparatus was immersed in an oil bath, and was carried out according to the temperature increase/depressurization program shown in the following Table 2. The final temperature was maintained at 217°C under a reduced pressure of 0.13 kPaA or less using a full vacuum pump (FV), and the polymerization was terminated 140 minutes after the start of the polymerization.

The weight average molecular weight (Mw) of the obtained bisphenol A-polypropylene glycol-polycarbonate copolymer (B1) was 15,400.

[Table 2]

[Production Example 2 of Polycarbonate Copolymer (B2)]

In a polymerization apparatus equipped with a 1L three-necked flask, 85% by mass of "VELVETOL H500" (Mw: 1700) manufactured by ALLESSA as polypropylene glycol, 15% by mass of bisphenol A, and 1.11 molar ratio of diphenyl carbonate to diol were added. As a catalyst, 5.0 μmol (in terms of Cs) of Cs ₂ CO ₃ aqueous solution was added per 1 mol of diol. After drying the system for 1 hour, the inside of the polymerization apparatus was re-pressurized with nitrogen. The polymerization was started when the re-pressurized polymerization apparatus was immersed in an oil bath, and was carried out according to the temperature increase/depressurization program shown in the following Table 3. The final temperature was maintained at 217°C under a reduced pressure condition of 0.13 kPaA or less using a full vacuum pump (FV), and the polymerization was terminated 320 minutes after the start of the polymerization.

The weight average molecular weight (Mw) of the obtained bisphenol A-polypropylene glycol-polycarbonate copolymer (B1) was 18,800.

[Table 3]

[Production Example 3 of Polycarbonate Copolymer (B3)]

In a polymerization apparatus equipped with a 1L three-necked flask, 85% by mass of "VELVETOL H500" (Mw: 1700) manufactured by ALLESSA as polytrimethylene glycol, 15% by mass of bisphenol A, and 1.10 molar ratio of diphenyl carbonate to diol were added. As a catalyst, 4.9 μmol (in terms of Cs) of Cs ₂ CO ₃ aqueous solution was added per 1 mol of diol. After drying the system for 1 hour, the inside of the polymerization apparatus was re-pressurized with nitrogen. The polymerization was started when the re-pressurized polymerization apparatus was immersed in an oil bath, and was carried out according to the temperature increase/depressurization program shown in the following Table 4. The final temperature was maintained at 217°C under a reduced pressure condition of 0.13 kPaA or less using a full vacuum pump (FV), and the polymerization was terminated 350 minutes after the start of the polymerization.

The weight average molecular weight (Mw) of the obtained bisphenol A-poly(n-propylene glycol)-polycarbonate copolymer (B3) was 22,800.

[Table 4]

[Production Example 4 of Polycarbonate Copolymer (B4)]

In a polymerization apparatus equipped with a 1L three-necked flask, 85% by mass of "VELVETOL H500" (Mw: 1700) manufactured by ALLESSA as polytrimethylene glycol, 15% by mass of bisphenol A, and 1.07 molar ratio of diphenyl carbonate to diol were added. As a catalyst, 4.9 μmol (in terms of Cs) of Cs ₂ CO ₃ aqueous solution was added per 1 mol of diol. After drying the system for 1 hour, the inside of the polymerization apparatus was re-pressurized with nitrogen. The polymerization was started when the re-pressurized polymerization apparatus was immersed in an oil bath, and was carried out according to the temperature increase/depressurization program shown in the following Table 5. The final temperature was maintained at 217°C under a reduced pressure condition of 0.13 kPaA or less using a full vacuum pump (FV), and the polymerization was terminated 310 minutes after the start of the polymerization.

The weight average molecular weight (Mw) of the obtained bisphenol A-polypropylene glycol-polycarbonate copolymer (B4) was 34,100.

[Table 5]

[Production Example 5 of Polycarbonate Copolymer (Y1)]

In a polymerization apparatus equipped with a 1L three-necked flask, 85% by mass of "PTMG650" (Mw: 1950) manufactured by Mitsubishi Chemical Corporation as polytetramethylene glycol, 15% by mass of bisphenol A, and 1.15 molar ratio of diphenyl carbonate to diol were added. As a catalyst, 9.9 μmol (in terms of Cs) of a Cs ₂ CO ₃ aqueous solution was added per 1 mol of diol. After drying the system for 1 hour, the inside of the polymerization apparatus was re-pressurized with nitrogen. The polymerization was started when the re-pressurized polymerization apparatus was immersed in an oil bath, and was carried out according to the temperature increase/depressurization schedule shown in Table 6 below. The final temperature was maintained at 217°C under a reduced pressure of 0.13 kPaA or less using a full vacuum pump (FV), and the polymerization was terminated 140 minutes after the start of the polymerization.

The weight average molecular weight (Mw) of the obtained bisphenol A-polytetramethylene glycol-polycarbonate copolymer (Y1) was 22,800.

[Table 6]

(Examples 1 to 19, Comparative Examples 1 to 5)

[Manufacture of resin composition pellets]

The above-mentioned components were blended in the ratios (parts by mass) shown in the following Tables 7-9, mixed in a drum mixer for 20 minutes, and then melt-kneaded at a barrel temperature of 240°C using a single-screw extruder with a vent and a screw diameter of 40 mm ("VS-40" manufactured by Tanabe Plastic Machine Co., Ltd.), and strand-cut to obtain pellets.

[Strand transparency during production of resin composition pellets]

In the above-mentioned production process of the resin composition pellets, the transparency of the strands obtained by melt-kneading and extruding using an extruder was visually evaluated according to the following criteria.

A: The transparency of the extruded strand is extremely high, and the compatibility of the polycarbonate resin with the polycarbonate copolymer (B), polytetramethylene glycol, and other polycarbonate copolymers is extremely good.

B: The extruded strand has high transparency, and the compatibility of the polycarbonate resin with the polycarbonate copolymer (B), polytetramethylene glycol, and other polycarbonate copolymers is good.

C: The extruded strands were slightly turbid, and the compatibility of the polycarbonate resin with the polycarbonate copolymer (B), polytetramethylene glycol, and other polycarbonate copolymers was poor.

D: The extruded strands were extremely turbid, and the compatibility of the polycarbonate resin with the polycarbonate copolymer (B), polytetramethylene glycol, and other polycarbonate copolymers was extremely poor.

[Flowability evaluation (Q value)]

The obtained pellets were dried at 120°C for more than 5 hours, and the flow rate Q value (unit: ×10 ^-2 cm ³ /sec) of the composition per unit time was measured using a high-grade flow tester at 280°C and a load of 160 kgf by the method described in JIS K7210 Appendix C to evaluate the fluidity. It should be noted that the orifice used had a diameter of 1 mm and a length of 10 mm.

The higher the Q value, the better the fluidity.

[Impact resistance evaluation (Charpy impact strength)]

The obtained pellets were dried at 120°C for 5 hours, and then an impact resistance test piece with a thickness of 3 mm was prepared using an injection molding machine ("NEX80III" manufactured by Nissei Plastic Industry Co., Ltd.) under the conditions of a cylinder temperature of 250°C, a mold temperature of 80°C, and a molding cycle of 45 seconds in accordance with ISO179-1, 2. The obtained test piece was subjected to notch cutting with R0.25 mm/depth of 2 mm, and the Charpy notched impact strength (kJ/m ² ) was measured under a temperature environment of 23°C.

[Evaluation of mold contamination (mold deposits)]

Contamination evaluation in injection molding (mold stains)

The pellets obtained in the above were dried at 120°C for 5 hours, and then injection molded by an injection molding machine ("SE7M" manufactured by Sumitomo Heavy Industries, Ltd.) using a teardrop-shaped mold as shown in FIG. 1, with a cylinder temperature of 340°C, a molding cycle of 10 seconds, and a mold temperature of 40°C. 200 shots were injected, and the state of contamination caused by white attachments generated on the metal mirror surface on the fixed side of the mold after completion was determined by visual evaluation according to the following criteria.

A: There is very little mold attachment and excellent resistance to mold contamination.

B: There is little mold attachment, but a little mold contamination resistance is observed.

C: There are many mold attachments and mold contamination is observed.

D: There are many mold attachments and mold contamination is significantly observed.

It should be noted that the teardrop-shaped mold in FIG1 is a mold designed in such a way that the resin composition is introduced from the gate G and the generated gas can easily slide at the tip P. The gate G has a width of 1 mm and a thickness of 1 mm. In FIG1 , the width h1 is 14.5 mm, the length h2 is 7 mm, the length h3 is 27 mm, and the thickness of the molded portion is 3 mm.

[Hue (YI) and ΔYI (Evaluation of Heat Discoloration Resistance)]

The obtained pellets were dried at 120°C for 5 to 7 hours in a hot air circulation dryer and then molded into a long optical path molded product (300 mm×7 mm×4 mm) at a resin temperature of 340°C and a mold temperature of 80°C using an injection molding machine (Sodick "HSP100A").

The YI value (yellowing degree) of the long optical path molded product was measured at an optical path length of 300 mm. The measurement was performed using a long optical path spectral transmission colorimeter ("ASA 1" manufactured by Nippon Denshoku Industries Co., Ltd., C light source, 2° field of view).

Next, the long optical path molded product was kept at 95° C. for 1000 hours, and the YI value was measured at an optical path length of 300 mm. The difference ΔYI from the initial YI value was calculated to evaluate the heat discoloration resistance.

The above evaluation results are shown in the following Tables 7-9.

[Table 7]

[Table 8]

[Table 9]

Industrial Applicability

The polycarbonate resin composition of the present invention has excellent impact resistance, good hue, and excellent transparency, and generates very little gas and mold contamination during molding, and can be extremely suitably used for various molded products, especially optical parts.

Claims (10)

1. A polycarbonate resin composition, characterized in that, with respect to 100 parts by mass of the polycarbonate resin (A), 0.1 to 10 parts by mass of the polycarbonate copolymer (B) and a phosphorus-based stabilizer (C) are contained 0.005～0.5 parts by mass, The polycarbonate copolymer (B) is formed from (B1) bisphenol A and (B2) optionally substituted polypropylene glycol based on carbonate bonds, The mass ratio of (B1) bisphenol A and (B2) polypropylene glycol constituting the polycarbonate copolymer (B) is 5 mass % or more based on the total of (B1) and (B2) 100 mass % And less than 50% by mass, (B2) is more than 50% by mass and 95% by mass or less. 2. polycarbonate resin composition according to claim 1, wherein, the initial YI value of 300mm optical path length is less than 25, and 95 ℃ keeps the YI value of 300mm optical path length after 1000 hours and the difference between initial YI value (ΔYI ) is 6 or less. 3 . The polycarbonate resin composition according to claim 1 , wherein (B2) polyn-propylene glycol constituting the polycarbonate copolymer (B) has a weight average molecular weight (Mw) of 600 to 8,000. 4 . 4. The polycarbonate resin composition according to claim 1 or 2, wherein the polycarbonate copolymer (B) has a weight average molecular weight (Mw) of 5,000 to 40,000. 5 . The polycarbonate resin composition according to claim 3 , wherein the polycarbonate copolymer (B) has a weight average molecular weight (Mw) of 5,000 to 40,000. 6. The polycarbonate resin composition according to any one of claims 1, 2, and 5, wherein the Charpy notched impact strength of a molded article having a thickness of 3 mm based on ISO179 is 25 kJ/m ² or more. 7. The polycarbonate resin composition according to claim 3, wherein the Charpy notched impact strength of a molded article having a thickness of 3 mm based on ISO179 is 25 kJ/m ² or more. 8. The polycarbonate resin composition according to claim 4, wherein the Charpy notched impact strength of a molded article having a thickness of 3 mm based on ISO179 is 25 kJ/m ² or more. 9. A molded article of the polycarbonate resin composition according to any one of claims 1 to 8. 10. The molded article according to claim 9, which is an optical component.

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