JP2023065802A - Polycarbonate resin composition - Google Patents

Abstract

To provide a polycarbonate resin composition which has high heat resistance and is excellent in retention stability, and satisfies total light transmittance and diffusibility in a balanced manner.SOLUTION: A polycarbonate resin composition contains, with respect to 100 pts.mass of a polycarbonate resin (A), 0.2-1.0 pts.mass of crosslinked acrylic polymer particles (B), 0.01-0.5 pts.mass of an acid phosphate compound (C), and 0.0001-0.5 pts.mass of a phosphorus-based antioxidant (D), wherein the crosslinked acrylic polymer particles (B) have a 10% weight reduction temperature measured by a calorimetry apparatus of 330°C or higher.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin composition which has high heat resistance, excellent retention stability, and satisfies a good balance between total light transmittance and diffusivity, and a molded article thereof.

Polycarbonate resin is a highly functional resin with excellent physical properties such as impact resistance, heat resistance, weather resistance, and flame resistance, and high light transmittance. In recent years, it has come to be used as parts for lighting equipment and optical members.

Among these, lighting covers, various displays, vehicle light guides, etc., which use LEDs as light sources, are provided with light diffusing properties to spread the illumination light, which does not reduce the lighting efficiency. It is required to maintain such high light diffusibility and light transmittance.

Various polycarbonate resin compositions containing acrylic resin particles such as polymethyl methacrylate have been proposed as polycarbonate resins imparted with light diffusion properties. It has also been proposed to add silicone particles instead of the acrylic resin particles.
However, although silicone-based particles have excellent heat resistance, the optical properties that require both light transmittance and light diffusion are not sufficient compared to acrylic resin particles, and acrylic resin particles are useful.

In recent years, lighting parts and optical members come in various shapes and are becoming larger and longer. For example, long optical members exceeding 1 m have appeared. there is When such a long molded product is injection molded, the resin composition stays at a high temperature for a long time, so the retention deterioration is severe, and the decrease in the viscosity of the raw material resin may make it impossible to mold. It is essential to be excellent in

Patent Literature 1 describes an invention in which a phosphite-based antioxidant is contained in an acrylic resin diffusing agent and then blended with the polycarbonate resin to prevent discoloration of the polycarbonate resin. However, it is not easy to produce a diffusing agent containing a phosphite-based antioxidant, and the effect of the phosphite-based antioxidant is not necessarily sufficient.

Japanese Patent No. 4711796

The present invention has been made in view of the above circumstances, and provides a polycarbonate resin composition which has high heat resistance, excellent retention stability, and satisfies a good balance between total light transmittance and diffusivity in a system containing acrylic resin particles. The task (objective) is to provide

In order to achieve the above object, the present inventors have made intensive studies and found that, in a polycarbonate resin, crosslinked acrylic polymer particles (B) having a 10% weight loss temperature of a specific temperature or higher, an acidic phosphate compound ( The present inventors have found that the above problems can be solved by adding specific amounts of C) and the phosphorus-based antioxidant (D), respectively, and have completed the present invention.
The present invention relates to the following polycarbonate resin composition and molded article.

1. Per 100 parts by mass of the polycarbonate resin (A), 0.2 to 1.0 parts by mass of the crosslinked acrylic polymer particles (B), 0.01 to 0.5 parts by mass of the acidic phosphate ester compound (C), and 0.0001 to 0.5 parts by mass of a phosphorus antioxidant (D), and the 10% weight loss temperature of the crosslinked acrylic polymer particles (B) measured by a calorimeter is 330 ° C. or higher. A polycarbonate resin composition characterized by:
2. 2. The polycarbonate resin composition according to 1 above, further comprising 0.0001 to 0.5 parts by mass of a phenolic antioxidant (E) with respect to 100 parts by mass of the polycarbonate resin (A).
3. 3. The polycarbonate resin composition as described in 1 or 2 above, wherein the acidic phosphoric acid ester compound (C) is one or more phosphates selected from alkyl acid phosphates, alkenyl acid phosphates and metal salts thereof.
4. A molded article made of the polycarbonate resin composition according to any one of 1 to 3 above.
5. 4. The molded article as described in 4 above, which is a lighting component or an optical member.

The polycarbonate resin composition of the present invention has high heat resistance and excellent retention stability, satisfies a good balance between total light transmittance and diffusibility, and is also excellent in moldability.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to embodiments, examples, and the like.
In this specification, unless otherwise specified, the term "~" is used to mean that the numerical values before and after it are included as lower and upper limits.

The polycarbonate resin composition of the present invention contains 0.2 to 1.0 parts by mass of the crosslinked acrylic polymer particles (B) and 0 parts by mass of the acidic phosphate ester compound (C) per 100 parts by mass of the polycarbonate resin (A). .01 to 0.5 parts by mass and 0.0001 to 0.5 parts by mass of a phosphorus antioxidant (D), and 10% weight measured by a calorimeter of crosslinked acrylic polymer particles (B) The reduction temperature is 330° C. or higher.
Hereinafter, each component, molded article, etc., constituting the polycarbonate resin composition of the present invention will be described in detail.

[Polycarbonate resin (A)]
The polycarbonate resin (A) used in the present invention is not particularly limited, and various resins can be used. Polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbons directly bonded to the carbonic acid bonds are aromatic carbons, and aliphatic polycarbonate resins in which the carbons directly bonded to the carbonic acid bonds are aliphatic carbons, and either can be used. Among them, as the polycarbonate resin (A), an aromatic polycarbonate resin is preferable from the viewpoint of heat resistance, mechanical properties, electrical properties, and the like.

Examples of aromatic dihydroxy compounds among monomers that are raw materials for aromatic polycarbonate resins include:
Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (ie, resorcinol), 1,4-dihydroxybenzene;
Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl;

2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1 ,7-dihydroxynaphthalene, dihydroxynaphthalenes such as 2,7-dihydroxynaphthalene;

2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy) dihydroxy diaryl ethers such as benzene, 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 (i.e. bisphenol C),
2,2-bis(3-methoxy-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane,
1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane,
2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane,
α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
bis(4-hydroxyphenyl)methane,
bis(4-hydroxyphenyl)cyclohexylmethane,
bis(4-hydroxyphenyl)phenylmethane,
bis(4-hydroxyphenyl)(4-propenylphenyl)methane,
bis(4-hydroxyphenyl)diphenylmethane,
bis(4-hydroxyphenyl)naphthylmethane,
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)-1-phenylethane,
1,1-bis(4-hydroxyphenyl)-1-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,
Bis(hydroxyaryl)alkanes such as;

1,1-bis(4-hydroxyphenyl)cyclopentane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane,
1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane,
Bis(hydroxyaryl)cycloalkanes such as;

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

4,4'-dihydroxydiphenyl sulfide,
Dihydroxydiarylsulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfide;
dihydroxydiarylsulfoxides such as 4,4'-dihydroxydiphenylsulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfoxide;
4,4'-dihydroxydiphenyl sulfone,
Dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone;
etc.

Among these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are particularly preferred, and 2,2-bis(4-hydroxyphenyl)propane ( That is, bisphenol A) and 2,2-bis(3-methyl-4-hydroxyphenyl)propane (ie, bisphenol C) are preferred.
In addition, 1 type may be used for an aromatic dihydroxy compound, and it may use 2 or more types together by arbitrary combinations and ratios.

Carbonyl halides, carbonate esters and the like are used as examples of carbonate precursors among the monomers used as raw materials for polycarbonate resins. In addition, one type of carbonate precursor may be used, or two or more types may be used together in an arbitrary combination and ratio.

Specific examples of carbonyl halides include phosgene; haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds.

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

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

The molecular weight of the polycarbonate resin (A) is preferably 10,000 to 50,000, more preferably 10,000 to 40,000 as a viscosity-average molecular weight (Mv) converted from a solution viscosity measured at a temperature of 25° C. using methylene chloride as a solvent. , especially 10,000 to 30,000, 10,000 to 26,000, more preferably 10,500 or more, 11,000 or more, particularly 11,500 or more, most preferably 12,000 or more, furthermore 24,000 or less, particularly preferably 20,000 or less. By setting the viscosity-average molecular weight to the lower limit of the above range or more, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved. The decrease in fluidity of the polycarbonate resin composition of the present invention can be suppressed and improved, and the moldability can be enhanced to facilitate thin-wall molding.
Two or more kinds of polycarbonate resins having different viscosity-average molecular weights may be mixed and used, and in this case, polycarbonate resins having viscosity-average molecular weights outside the preferred range may be mixed.

The viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and determining the intrinsic viscosity [η] (unit dl / g) at a temperature of 25 ° C. using an Ubbelohde viscometer. , η=1.23×10 ⁻⁴ Mv ^0.83 . In addition, the intrinsic viscosity [η] is a value calculated from the following formula by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g/dl).

Further, the polycarbonate resin (A) may contain a polycarbonate oligomer in order to improve the appearance and fluidity of the molded product. The viscosity-average molecular weight [Mv] of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Further, the polycarbonate oligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Further, the polycarbonate resin (A) may be not only a virgin raw material but also a polycarbonate resin recycled from a used product (so-called material-recycled polycarbonate resin).
However, the content of the recycled polycarbonate resin in the polycarbonate resin (A) is preferably 80% by mass or less, more preferably 50% by mass or less. Since recycled polycarbonate resins are likely to have undergone deterioration such as heat deterioration and aging, if such polycarbonate resins are used more than the above range, the hue and mechanical properties may be reduced. This is because of the nature of

[Crosslinked acrylic polymer particles (B)]
The polycarbonate resin composition of the present invention contains crosslinked acrylic polymer particles (B) and has a 10% weight loss temperature of 330° C. or higher as measured by a calorimeter.

Crosslinked acrylic polymer particles (B) are preferably crosslinked acrylic resin particles produced by suspension polymerization of a non-crosslinkable acrylic monomer and a crosslinkable monomer, preferably by suspension polymerization.
As the non-crosslinkable acrylic monomer, an acrylic monomer alone or a plurality of acrylic monomers are used in combination. Acrylic monomers include acrylic acid esters such as methyl acrylate, n-butyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethyl-hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. and methacrylic acid esters such as methacrylic acid esters, and these can be used alone or in combination of two or more. Among them, methyl methacrylate is preferably used.
In addition, monomers that can be copolymerized with (meth)acrylic acid ester monomers may be added to the monomers. Examples of such monomers include styrene, α-methylstyrene, A monomer having a vinyl group such as vinyl acetate can be mentioned.

A compound having two or more unsaturated bonds in the molecule is preferably used as the crosslinkable monomer. For example, trimethylolpropane tri(meth)acrylate, allyl methacrylate, triallyl cyanurate, triallyl isocyanate, ethylene glycol dimethacrylate, propylene glycol diallyl ether, divinylbenzene, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate. etc. Among them, trimethylolpropane tri(meth)acrylate is preferred.

The crosslinked acrylic polymer particles (B) can be produced by suspension polymerization of a non-crosslinkable acrylic monomer and a crosslinkable monomer. For example, both monomers are suspended in polyvinyl alcohol as a dispersant, polymerized, filtered, washed, sieved, and dried. The ratio of the two monomers to be used is preferably 90 to 99% by mass of the non-crosslinkable acrylic monomer and 10 to 1% by mass of the crosslinkable monomer. If the amount of the crosslinkable monomer is too small, the obtained bead-shaped crosslinked acrylic polymer particles tend to be poorly dispersed in the polycarbonate resin, and the 10% weight loss temperature is raised by increasing the amount of the crosslinkable monomer. However, if it is too large, the crosslinked acrylic polymer particles become too hard and the impact strength tends to decrease, which is not preferable.

The 10% weight loss temperature of the crosslinked acrylic polymer particles (B) is 330°C or higher. change and haze change were also found to be small. The 10% weight loss temperature is preferably 335° C. or higher, more preferably 340° C. or higher, 345° C. or higher, 350° C. or higher, 355° C. or higher, 360° C. or higher, and particularly preferably 365° C. or higher. The upper limit is usually up to about 400° C. in the case of a crosslinked acrylic polymer.

The 10% weight loss temperature is measured by a calorimeter (TGA) under a nitrogen atmosphere in the process of raising the temperature from 40°C to 520°C at a rate of 10°C/min. is measured, and the specific method is as described in Examples.

In order to obtain crosslinked acrylic polymer particles (B) having a 10% weight loss temperature of 330° C. or higher, it is possible to increase the amount of crosslinkable monomer or increase the molecular weight of the polymer by a conventional method. It is also possible to select and use from commercially available products.

The crosslinked acrylic polymer particles (B) preferably have an average particle size of 1 to 10 μm. When the average particle size is within this range, the light diffusion rate and the degree of dispersion are further improved. The average particle size is preferably 1.5-7 μm, more preferably 2-4 μm. In addition, the measurement of the particle diameter is D50 performed on a number basis by the Coulter counter method.

The content of the crosslinked acrylic polymer particles (B) is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). ) and a specific amount of the phosphorus-based antioxidant (D), it is possible to obtain a polycarbonate resin composition that has high heat resistance, excellent retention stability, and satisfies a good balance between total light transmittance and diffusivity. A preferable amount of the crosslinked acrylic polymer particles (B) is 0.2 to 0.9 parts by mass, more preferably 0.2 to 0.8 parts by mass.

[Acidic phosphate ester compound (C)]
The polycarbonate resin composition of the present invention contains an acidic phosphate compound (C).
As the acidic phosphoric acid ester compound (C), one or more phosphates selected from alkyl acid phosphates, alkenyl acid phosphates and metal salts thereof are preferred.

The alkyl acid phosphate or alkenyl acid phosphate is preferably represented by the following formula (I). The alkyl acid phosphate or alkenyl acid phosphate is represented by the following general formula (I), and the alkyl acid phosphate metal salt or alkenyl acid phosphate metal salt is a zinc salt of an alkyl acid phosphate or alkenyl acid phosphate represented by the following formula (I). , aluminum salts and the like.
O=P(OH) _n (OR) _3-n (I)
(In the formula, R is an alkyl group or alkenyl group having 9 to 30 carbon atoms, and n represents an integer of 1 or 2. When n is 1, the two R may be the same or different. may be used.)

The alkyl group represented by R in the above formula (I) may be a linear alkyl group or may have a branch. Specific examples of alkyl groups for R include nonyl, isononyl, decyl, isodecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl (stearyl), eicosyl, and tetracosyl groups. Also, the alkenyl group represented by R may be a straight-chain alkenyl group or may have a branch. Specific examples of the alkenyl group for R include an oleyl group and the like. n is 1 or 2, and may be a mixture thereof.

The number of carbon atoms in the alkyl or alkenyl group represented by R in the above formula (I) is more preferably 13, 18, or 24, and the alkyl acid phosphate is particularly represented by the following formula (II): and is a mixture of distearyl acid phosphate with n=1 and monostearyl acid phosphate with n=2 in formula (II).
O=P(OH) _{n ( OC18H37} ) _3-n (II)

As the metal salt of alkyl acid phosphate, a mixture of a distearyl acid phosphate zinc salt represented by the following formula (IIIa) and a monostearyl acid phosphate zinc salt represented by the following formula (IIIb) is preferable.

The content of the acidic phosphate ester compound (C) is 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin. By combining specific amounts of the crosslinked acrylic polymer particles (B) and the phosphorus antioxidant (D) within such a range, high heat resistance, excellent retention stability, and a good balance between total light transmittance and diffusivity can be obtained. A highly satisfactory polycarbonate resin composition can be obtained. The content of the acidic phosphate ester compound (C) is preferably 0.015 parts by mass or more, more preferably 0.02 parts by mass or more, and preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass. part or less, especially 0.2 mass part or less, 0.1 mass part or less, 0.08 mass part or less, and 0.05 mass part or less.

[Phosphorus-based antioxidant (D)]
The polycarbonate resin composition of the present invention further contains a phosphorus antioxidant (D).
The content of the phosphorus antioxidant (D) is 0.0001 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin. By combining the specific amounts of the crosslinked acrylic polymer particles (B) and the acidic phosphate ester compound (C) within these ranges, high heat resistance, excellent retention stability, and a good balance between total light transmittance and diffusivity can be obtained. A highly satisfactory polycarbonate resin composition can be obtained. The content of the phosphorus antioxidant (D) is preferably 0.001 parts by mass or more, more 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. , especially preferably 0.2 parts by mass or less, 0.1 parts by mass or less, 0.08 parts by mass or less, and particularly preferably 0.05 parts by mass or less.

Phosphorus-based antioxidants (D) include phosphorous acid, phosphoric acid, phosphites, and phosphate esters (excluding the acidic phosphate compound (C) described above). Phosphites such as phosphites and phosphonites are preferred in that they contain a valence of phosphorus and tend to exhibit discoloration-inhibiting effects.

Examples of phosphites include triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite. Phyto, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra (tridecyl) pentaerythritol tetraphosphite, water Added bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl)phosphite), tetra(tridecyl)4,4′- isopropylidene diphenyl diphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris(4-tert- butylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite , bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2′-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, bis(2, 4-dicumylphenyl)pentaerythritol diphosphite and the like.

Phosphonites include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenyl diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite night, tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite, tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, Tetrakis (2,6-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis ( 2,6-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite and the like.

Among the phosphites, distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)penta Erythritol diphosphite, 2,2′-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite are preferred, and have good heat resistance. Tris(2,4-di-tert-butylphenyl)phosphite is particularly preferred because of its consistency and resistance to hydrolysis.

The phosphorus antioxidant (D) may be used alone or in combination of two or more.

[Phenolic antioxidant (E)]
The polycarbonate resin composition of the present invention preferably contains a phenolic antioxidant (E). By containing a phenol-based antioxidant, it is possible to suppress the deterioration of hue and the deterioration of mechanical properties during heat retention.

Examples of the phenolic antioxidant (E) include hindered phenolic antioxidants. Specific examples include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl ) propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di- tert-butyl-4-hydroxyphenylpropionamide), 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl ]methyl]phosphoate, 3,3′,3″,5,5′,5″-hexa-tert-butyl-a,a′,a″-(mesitylene-2,4,6-triyl)tri -p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene Bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3 ,5-triazine-2,4,6(1H,3H,5H)-trione,2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine- 2-ylamino)phenol and the like.

Among them, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. . Examples of commercially available phenolic antioxidants include "Irganox 1010" and "Irganox 1076" manufactured by BASF, "ADEKA STAB AO-60" and "ADEKA STAB AO-50" manufactured by ADEKA. be done.

Phenolic antioxidants (E) may be used alone or in combination of two or more.

When the phenolic antioxidant (E) is contained, the content thereof is preferably 0.0001 parts by mass or more, more preferably 0.001 parts by mass or more, and still more preferably 100 parts by mass of the polycarbonate resin (A). is 0.01 parts by mass or more, preferably 0.5 parts by mass or less, more preferably 0.4 parts by mass or less, still more preferably 0.3 parts by mass or less, especially 0.2 parts by mass or less, 0.1 0.08 parts by mass or less, particularly preferably 0.05 parts by mass or less. By combining the specific amounts of the crosslinked acrylic polymer particles (B), the acidic phosphate ester compound (C) and the phosphorus antioxidant (D) within such a range, high heat resistance and excellent retention stability can be obtained. , a polycarbonate resin composition that satisfies a good balance of total light transmittance and diffusivity.

[Ultraviolet absorber (F)]
The polycarbonate resin composition of the present invention preferably contains an ultraviolet absorber (F).
Examples of the ultraviolet absorber (F) include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide; and organic ultraviolet absorbers such as Among these, organic ultraviolet absorbers are preferred, and benzotriazole compounds are more preferred. By selecting the organic ultraviolet absorber, the resin composition of the present invention has good transparency and mechanical properties.

Specific examples of benzotriazole compounds include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl ) phenyl]-benzotriazole, 2-(2′-hydroxy-3′,5′-di-tert-butyl-phenyl)-benzotriazole, 2-(2′-hydroxy-3′-tert-butyl-5′ -methylphenyl)-5-chlorobenzotriazole, 2-(2′-hydroxy-3′,5′-di-tert-butyl-phenyl)-5-chlorobenzotriazole), 2-(2′-hydroxy-3 ',5'-di-tert-amyl)-benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3, 3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], among which 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2' -methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol] is preferred, especially 2-(2′-hydroxy-5′-tert- Octylphenyl)benzotriazole is preferred.

Specific examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxy Benzophenone, 2-hydroxy-n-dodecyloxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4 , 4′-dimethoxybenzophenone and the like.

Specific examples of salicylate compounds include phenyl salicylate and 4-tert-butylphenyl salicylate.
Specific examples of cyanoacrylate compounds include ethyl-2-cyano-3,3-diphenyl acrylate and 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate.
Specific examples of the oxanilide compound include 2-ethoxy-2'-ethyloxalinic acid bisallinide and the like.
As the malonic ester compound, 2-(alkylidene)malonic esters are preferable, and 2-(1-arylalkylidene)malonic esters are more preferable.

The content when containing the ultraviolet absorber (F) is usually 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and usually 1 Part by mass or less, preferably 0.5 part by mass or less. If the content of the UV absorber is less than the lower limit of the above range, the effect of improving weather resistance may be insufficient, and if the content of the UV absorber exceeds the upper limit of the range, mold Deposits and the like may occur and cause mold contamination.
One type of ultraviolet absorber may be contained, or two or more types may be contained in any combination and ratio.

[Release agent (G)]
It is also preferred that the resin composition of the present invention contains a release agent (G).
Examples of the release agent (G) 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 silicone oils.

Aliphatic carboxylic acids include, for example, saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acids. Here, the aliphatic carboxylic acid also includes alicyclic carboxylic acid. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, more preferably aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetralyacontanoic acid, montanic acid, and adipine. acid, azelaic acid, and the like.

As the aliphatic carboxylic acid in the ester of aliphatic carboxylic acid and alcohol, for example, the same aliphatic carboxylic acid as mentioned above can be used. Alcohols, on the other hand, include, for example, saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have substituents such as fluorine atoms and aryl groups. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic saturated monohydric alcohols or saturated aliphatic polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the term "aliphatic" is used as a term that also includes alicyclic compounds.

Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. are mentioned.

In addition, said ester may contain aliphatic carboxylic acid and/or alcohol as an impurity. Further, the above ester may be a pure substance, or may be a mixture of multiple compounds. Furthermore, the aliphatic carboxylic acids and alcohols that form one ester by combining may be used alone, or two or more of them may be used in any combination and ratio.

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

Aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include, for example, liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. In addition, an alicyclic hydrocarbon is also contained as an aliphatic hydrocarbon here. Also, these hydrocarbons may be partially oxidized.
Among these, paraffin wax, polyethylene wax, or partial oxides of polyethylene wax are preferable, and paraffin wax and polyethylene wax are more preferable.
Also, the number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.
The aliphatic hydrocarbon may be a single substance, or a mixture of substances having various constituents and molecular weights can be used as long as the main component is within the above range.

Examples of polysiloxane-based silicone oils include dimethylsilicone oil, methylphenylsilicone oil, diphenylsilicone oil, and fluorinated alkylsilicone.

In addition, 1 type may be contained in the release agent mentioned above, and 2 or more types may be contained in arbitrary combinations and ratios.

The content of the release agent (G) is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and more preferably 0.05 parts by mass or more with respect to 100 parts by mass of the polycarbonate resin (A). Also, it is usually 2 parts by mass or less, preferably 1 part by mass or less, more preferably 0.7 parts by mass or less, and still more preferably 0.5 parts by mass or less. If the content of the release agent is less than the lower limit of the above range, the releasability effect may not be sufficient, and if the content of the release agent exceeds the upper limit of the above range, hydrolysis resistance may cause a decrease in the product, mold contamination during injection molding, and the like.

[Additives, etc.]
The polycarbonate resin composition of the present invention contains other additives other than those described above, such as fluorescent brighteners, pigments, dyes, polymers other than polycarbonate resins, flame retardants, impact modifiers, antistatic agents, plasticizers, Additives such as agents, compatibilizers, etc. can be contained. These additives may be used alone or in combination of two or more.
However, when other polymers other than the polycarbonate resin (A) are contained, the content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, with respect to 100 parts by mass of the polycarbonate resin (A). It is preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less.

[Method for producing polycarbonate resin composition]
The method for producing the polycarbonate resin composition of the present invention is not limited, and a wide range of known methods for producing a polycarbonate resin composition can be employed. After pre-mixing using various mixers such as a tumbler and Henschel mixer, a method of melt-kneading with a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, and a kneader can be mentioned. The melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320°C.

[Molding]
The polycarbonate resin composition of the present invention can be produced into molded articles by molding pellets obtained by pelletizing the polycarbonate resin composition described above by various molding methods. Also, the resin melted and kneaded by the extruder can be directly molded into a molded product without going through pellets.

The polycarbonate resin composition of the present invention has high heat resistance and excellent retention stability. It is particularly suitably used for molding a molded article, for example, a long molded article having a length of more than 1 m, particularly 1 m50 cm or more.
Regarding the resin temperature during injection molding, it is possible to perform molding at a resin temperature higher than 260 to 300°C, which is common for polycarbonate resins, and it is also possible to use a resin temperature of over 300°C to 400°C.

Since the resin composition of the present invention has excellent retention stability, the total light transmittance change (3 mm thickness, Δtransmittance), haze value change (3 mm thickness, ΔHaze) and The flow value change (ΔQ) per unit time is preferably allowed to be:
Δ Transmittance (%) = | [initial total light transmittance] - [total light transmittance after 20 minutes of residence time] |
Preferably 3.0% or less, more preferably 2.5% or less, still more preferably 2.0% or less ΔHaze (%) =|[initial haze]−[haze after 20 minutes of residence time]|
It is preferably 1.2% or less, more preferably 1% or less, still more preferably 0.8% or less, especially 0.6% or less, 0.5% or less, and particularly preferably 0.3% or less.
ΔQ (×10 ⁻² cm ³ /sec)=|[Q value after 20 minutes of residence time]−[Initial Q value]|
It is preferably 4 or less, more preferably 3.5 or less, still more preferably 3 or less, especially 2.5 or less, 2 or less, and particularly preferably 1.5 or less.
The total light transmittance (%) of the resin composition of the present invention is preferably 60% or more, more preferably 70% or more, still more preferably 75% or more, and particularly preferably 80% or more as its initial value. be.
The initial value of haze is preferably 90% or higher, more preferably 95% or higher, and even more preferably 96% or higher.
The initial value of the Q value (×10 ⁻² cm ³ /sec) is preferably 11 or more, more preferably 13 or more, and even more preferably 14 or more.

Details of methods for measuring the total light transmittance, haze, and Q value and how to determine the Δ value are as described in Examples.

Molded articles are particularly suitable for lighting parts or optical members, and include parts of equipment and instruments that directly or indirectly use light sources such as LEDs, organic ELs, incandescent lamps, fluorescent lamps, and cathode tubes. Particularly suitable for long optical members having a long optical path length, for example, longer than 30 cm, longer than 50 cm, longer than 80 cm, especially longer than 100 cm, longer than 120 cm, especially longer than 150 cm.
A typical example is a light guide that efficiently guides light from one side of the light source to the other side using internal reflection. There is a diffusion cover for In addition, light guides for vehicle headlamps; light guides and diffusion covers for various types of lighting; illumination signboards; various display devices; It can also be suitably used for light plates, scanner light source units, various lenses, and the like.

The shape of the molded article may be long, flat, rod-shaped, cylindrical, spiral, lens-shaped, film-shaped, or sheet-shaped.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention should not be construed as being limited to the following examples.
Raw materials used in the following examples and comparative examples are shown in Table 1.

The 10% weight loss temperature of the above-mentioned crosslinked acrylic polymer particles, etc., was obtained by using a calorimeter "TG/DTA7200" manufactured by Hitachi High-Tech Science Co., Ltd. in a nitrogen atmosphere with a sample of 10 mg at a heating rate of 10 from 40 ° C. When the temperature was raised at a rate of °C/min, the temperature was measured at which the weight decreased by 10% when the weight at room temperature was taken as 100%.

(Examples 1 to 12, Comparative Examples 1 to 13)
[Production of resin composition pellets]
Each component described above was blended in the proportions (parts by mass) shown in Table 2 below, mixed in a tumbler for 20 minutes, then supplied to a twin-screw extruder (“TEM26SX” manufactured by Shibaura Kikai Co., Ltd.), and rotated with a screw. The mixture was kneaded under conditions of several 200 rpm, discharge rate of 25 kg/hour and barrel temperature of 280° C., and pellets were obtained by strand cutting.

[Total light transmittance (unit: %), haze (unit: %)]
After drying the pellets obtained by the above method at 120 ° C. for 5 hours with a hot air circulating dryer, an injection molding machine ("J55-60H" manufactured by Japan Steel Works, Ltd.) was used to mold at a cylinder temperature of 330 ° C. Under the conditions of a temperature of 80 ° C., a screw rotation speed of 100 rpm, and an injection speed of 40 mm / s, a three-stage plate [90 mm × 50 mm × thickness is 3 mm (length 20 mm) from the gate side, 2 mm (length 45 mm), 1 mm ( length 25 mm)] was molded. At this time, after molding in the normal cycle, the molding machine was temporarily stopped, and after holding the molten resin in the injection cylinder for 20 minutes, the three-stage plate was molded.
Using a haze meter "SH7000" manufactured by Nippon Denshoku Industries Co., Ltd., the total light transmittance (initial total light transmittance rate) and haze (initial haze) were measured.
Furthermore, the total light transmittance (initial total light transmittance) and haze (initial haze) of a 3 mm thick portion of the three-stage plate molded after holding the molten resin in the injection cylinder for 20 minutes were measured in the same manner as above. , the Δtransmittance and ΔHaze were obtained from the following equations.
Δ Transmittance (%) = | [initial total light transmittance] - [total light transmittance after 20 minutes of residence time] |
ΔHaze (%)=|[initial haze]−[haze after 20 minutes of residence time]|

[Flow value per unit time (Q value, unit: ×10 ^-2 cm ³ /sec)]
After drying the normal cycle three-stage plate obtained by the above method at 120 ° C. for 5 hours, using an elevated flow tester, the composition per unit time at a temperature of 280 ° C. and a load of 160 kgf A flow value (initial Q value, unit: ×10 ⁻² cm ³ /sec) was measured.
Furthermore, the Q value (Q value after a residence time of 20 minutes) of the three-stage plate molded after holding the molten resin in the injection cylinder obtained by the method described above for 20 minutes was measured in the same manner as described above. A ΔQ value was obtained from the formula.
ΔQ = | [Q value after 20 minutes of residence time] - [Initial Q value] |
A larger ΔQ value indicates that the decomposition of the polycarbonate resin progresses and the retention stability is poor.

The above evaluation results are shown in Table 2 below.

In addition, in Comparative Example 5 in Table 3 above, a large amount of silver was generated in the molded product, making it difficult to accurately evaluate the optical characteristics.

INDUSTRIAL APPLICABILITY The polycarbonate resin composition of the present invention has high heat resistance, excellent retention stability, and satisfies a good balance between total light transmittance and diffusivity, and therefore can be suitably used for various molded articles.

Claims (5)

Per 100 parts by mass of the polycarbonate resin (A), 0.2 to 1.0 parts by mass of the crosslinked acrylic polymer particles (B), 0.01 to 0.5 parts by mass of the acidic phosphate ester compound (C), and 0.0001 to 0.5 parts by mass of a phosphorus antioxidant (D), and the 10% weight loss temperature of the crosslinked acrylic polymer particles (B) measured by a calorimeter is 330 ° C. or higher. A polycarbonate resin composition characterized by: The polycarbonate resin composition according to claim 1, further comprising 0.0001 to 0.5 parts by mass of a phenolic antioxidant (E) with respect to 100 parts by mass of the polycarbonate resin (A). 3. The polycarbonate resin composition according to claim 1, wherein the acidic phosphoric acid ester compound (C) is one or more phosphates selected from alkyl acid phosphates, alkenyl acid phosphates and metal salts thereof. A molded article made of the polycarbonate resin composition according to any one of claims 1 to 3. 5. The molded article according to claim 4, which is an illumination part or an optical member.