JP7077049B2 - Polycarbonate resin composition - Google Patents

Description

The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin composition capable of cutting light having a wavelength of 400 to 420 nm on the visible light side of ultraviolet light and having no problem of gas generation during molding.

The eyes are constantly exposed to damage from sunlight, and it is important to protect them from UV light up to a wavelength of 400 nm. In addition, recent studies have revealed that the wavelength band on the visible light side from ultraviolet light also damages the tissues of the eye and causes the cause of cataracts and the like. Further, it has been reported that blue light, which is abundantly contained in LED light sources, causes eye diseases while devices and lighting using LEDs as light sources are widespread.
Therefore, in addition to ultraviolet light, there is a demand for a material that cuts wavelength light having a wavelength of 400 to 420 nm, which is closer to the visible light side.

In general, polycarbonate resin has excellent mechanical properties, weather resistance, and transparency, and a polycarbonate resin composition containing an ultraviolet absorber can be used as a transparent ultraviolet absorbing material for glasses, sunglasses, goggles, various lighting covers, and the like. in use. As the ultraviolet absorber, an ultraviolet absorber such as a benzophenone type, a benzotriazole type, a triazine type, or a salicylate type is used (for example, Patent Documents 1 and 2).
However, there is no known polycarbonate resin composition that can actually effectively absorb and block wavelengths of 400 to 420 nm.
Further, when trying to cut the 420 nm wavelength light with the conventional ultraviolet absorber as described above, there is a problem that the blending amount becomes large and the gas generation at the time of molding increases.

As described above, a resin composition composed of an ultraviolet absorber and a polycarbonate resin is known, but a polycarbonate resin composition capable of effectively absorbing and blocking wavelengths of 400 to 420 nm and having no problem of gas generation during molding is known. The current situation is that it has not been done.

Japanese Unexamined Patent Publication No. 09-291205 Special Fair No. 06-51840

The present invention has been made in view of the above circumstances, and an object (problem) thereof is to be able to cut wavelength light of 400 to 420 nm on the more visible light side in addition to ultraviolet light, and to generate gas during molding. It is an object of the present invention to provide a polycarbonate resin composition having no problem.

As a result of diligent studies to achieve the above problems, the present inventor has benzotriazole-based ultraviolet absorbers having a specific structure having a cesamole group, benzotriazole-based ultraviolet absorbers having no cesamole group, and triazine-based ultraviolet absorbers. By containing at least one UV absorber selected from agents, malonic acid ester-based UV absorbers and benzoxazine-based UV absorbers in a specific amount and amount ratio, and further containing a stabilizer, the above-mentioned problems can be solved. We have found that it can be solved and have completed the present invention.
The present invention relates to the following polycarbonate resin compositions.

（一般式（１）中、Ｒは水素原子、炭素数１～８のアルキル基、炭素数１～８のアルコキシ基、ヒドロキシル基、カルボキシル基、アルキル基の炭素数が１～８のアルキルオキシカルボニル基、炭素数１～８のヒドロキシアルキル基又はアルキル基の炭素数が各々１～８のアルキルカルボニルオキシアルキル基を表す。）
［２］ＪＩＳ Ｋ７１０５に準拠して厚み２ｍｍの成形体を波長４２０ｎｍで測定した透過率が２５％以下である請求項［１］に記載のポリカーボネート樹脂組成物。
［３］ＪＩＳ Ｋ７１０５に準拠して厚み２ｍｍの成形体を波長３２０ｎｍで測定した透過率が０．５％以下である請求項［１］又は［２］に記載のポリカーボネート樹脂組成物。
［４］請求項［１］～［３］のいずれかに記載のポリカーボネート樹脂組成物の成形品。 [1] 0.075 to 0.15 parts by mass of a benzotriazole-based ultraviolet absorber (B1) having a sesamole group represented by the following general formula (1) with respect to 100 parts by mass of the polycarbonate resin (A), a sesamole group. At least one UV absorber (B2) selected from a benzotriazole-based UV absorber, a triazine-based UV absorber, a malonate ester-based UV absorber, and a benzoxazine-based UV absorber (B2) 0.075 to 0. It contains 2 parts by mass and 0.01 to 0.5 parts by mass of the stabilizer (C), and the mass ratio (B2) / (B1) of the contents of the ultraviolet absorber (B2) and (B1) is more than 1. A polycarbonate resin composition characterized by the following.

(In the general formula (1), R is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a hydroxyl group, a carboxyl group, and an alkyloxycarbonyl having an alkyl group having 1 to 8 carbon atoms. A group, a hydroxyalkyl group having 1 to 8 carbon atoms, or an alkylcarbonyloxyalkyl group having an alkyl group having 1 to 8 carbon atoms, respectively.)
[2] The polycarbonate resin composition according to claim [1], wherein the molded product having a thickness of 2 mm and having a transmittance of 25% or less measured at a wavelength of 420 nm according to JIS K7105.
[3] The polycarbonate resin composition according to claim [1] or [2], wherein the molded product having a thickness of 2 mm in accordance with JIS K7105 has a transmittance of 0.5% or less measured at a wavelength of 320 nm.
[4] The molded product of the polycarbonate resin composition according to any one of claims [1] to [3].

The polycarbonate resin composition of the present invention can cut wavelength light having a wavelength of 400 to 420 nm on the visible light side in addition to ultraviolet light, and has no problem of gas generation during molding.

It is a top view of the drop mold used for the evaluation of mold contamination in an Example.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples.
In addition, in this specification, "-" is used in the meaning which includes the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

In the polycarbonate resin composition of the present invention, a benzotriazole-based ultraviolet absorber (B1) having a sesamole group represented by the general formula (1) is 0.075 to 0. To 100 parts by mass of the polycarbonate resin (A). At least one UV absorber selected from 15 parts by mass, a benzotriazole-based UV absorber having no sesamole group, a triazine-based UV absorber, a malonate ester-based UV absorber, and a benzoxazine-based UV absorber (B2). It contains 0.075 to 0.2 parts by mass and 0.01 to 0.5 parts by mass of the stabilizer (C), and the mass ratio (B2) / (B2) of the contents of the ultraviolet absorbers (B2) and (B1). It is characterized in that B1) is more than 1 and 2 or less.

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

[Polycarbonate resin (A)]
The polycarbonate resin is a polymer having a basic structure having a carbonic acid bond represented by the formula:-[-O-X-OC (= O)-]-. In the formula, X is generally a hydrocarbon, but a heteroatom or an X having a heterobond introduced may be used to impart various properties.

Further, the polycarbonate resin can be classified into an aromatic polycarbonate resin in which the carbon directly bonded to the carbonic acid bond is an aromatic carbon and an aliphatic polycarbonate resin in which the carbon is an aliphatic carbon, and any of them can be used. Of these, aromatic polycarbonate resins are preferable from the viewpoints of heat resistance, mechanical properties, electrical characteristics, and the like.

The specific type of the polycarbonate resin is not limited, and examples thereof include a polycarbonate polymer obtained by reacting a dihydroxy compound with a carbonate precursor. At this time, in addition to the dihydroxy compound and the carbonate precursor, a polyhydroxy compound or the like may be reacted. Further, a method of reacting with cyclic ether using carbon dioxide as a carbonate precursor may also be used. Further, the polycarbonate polymer may be linear or branched. Further, the polycarbonate polymer may be a homopolymer composed of one type of repeating unit or a copolymer having two or more types of repeating units. At this time, as the copolymer, various copolymer forms such as a random copolymer and a block copolymer can be selected. Usually, such a polycarbonate polymer becomes a thermoplastic resin.

Among the monomers used as raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds 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, 2,7-dihydroxynaphthalene and other 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) Dihydroxydiaryl ethers such as benzene and 1,3-bis (4-hydroxyphenoxy) benzene;

2,2-Bis (4-hydroxyphenyl) propane (ie, 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,
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'-Dihydroxydiphenylsulfide,
Dihydroxydiarylsulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfide;

Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;

4,4'-Dihydroxydiphenyl sulfone,
Dihydroxydiaryl sulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone;
And so on.

Among these, bis (hydroxyaryl) alkanes are preferable, and bis (4-hydroxyphenyl) alkanes are particularly preferable, and 2,2-bis (4-hydroxyphenyl) propane (particularly from the viewpoint of impact resistance and heat resistance). That is, bisphenol A) is preferable.
As the aromatic dihydroxy compound, one kind may be used, or two or more kinds may be used in any combination and ratio.

To give an example of a monomer that is a raw material for an aliphatic polycarbonate resin,
Etan-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3- Alkanediols such as diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, decane-1,10-diol;

Cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4- (2-hydroxyethyl) cyclohexanol, 2,2,4 Cycloalkanediols such as 4-tetramethyl-cyclobutane-1,3-diol;

Glycols such as ethylene glycol, 2,2'-oxydiethanol (ie, diethylene glycol), triethylene glycol, propylene glycol, spiroglycol;

1,2-Benzene dimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis ( 2-Hydroxyethoxy) benzene, 2,3-bis (hydroxymethyl) naphthalene, 1,6-bis (hydroxyethoxy) naphthalene, 4,4'-biphenyldimethanol, 4,4'-biphenyldiethanol, 1,4- Aralkyldiols such as bis (2-hydroxyethoxy) biphenyl, bisphenol A bis (2-hydroxyethyl) ether, bisphenol S bis (2-hydroxyethyl) ether;

1,2-Epoxyethane (ie, ethylene oxide), 1,2-epoxypropane (ie, propylene oxide), 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,4-epoxycyclohexane, 1-methyl Cyclic ethers such as -1,2-epoxycyclohexane, 2,3-epoxynorbornane, and 1,3-epoxypropane; and the like.

Among the monomers used as raw materials for the polycarbonate resin, carbonyl halides, carbonate esters and the like are used as examples of carbonate precursors. As the carbonate precursor, one kind may be used, or two or more kinds may be used in any combination and ratio.

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

Specific examples of the carbonate ester include diaryl carbonates such as diphenyl carbonate and ditril carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonate form of dihydroxy compound, monocarbonate form of dihydroxy compound, and cyclic carbonate. Examples thereof include carbonates of dihydroxy compounds such as.

The method for producing the polycarbonate resin 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 for a cyclic carbonate compound, and a solid phase transesterification method for a prepolymer.

The molecular weight of the polycarbonate resin (A) is preferably in the range of 16,000 to 50,000 in viscosity average molecular weight (Mv), more preferably 18,000 or more, still more preferably 20,000 or more, still more preferably 45,000 or less, still more preferably. Is 40,000, particularly preferably 38,000 or less. If the viscosity average molecular weight is smaller than 16000, the impact resistance of the molded product tends to decrease and cracks may occur, which is not preferable. If the viscosity average molecular weight is larger than 50,000, the fluidity deteriorates and the moldability becomes a problem. It is not preferable because it is easy.
The polycarbonate resin (A) may be used by mixing two or more types of polycarbonate resins having different viscosity average molecular weights. In this case, a polycarbonate resin having a viscosity average molecular weight outside the above-mentioned suitable range is mixed. You may.

In the present invention, the viscosity average molecular weight [Mv] of the polycarbonate resin is the ultimate viscosity [η] (unit: dl / g) at a temperature of 25 ° C. using a Ubbelohde viscometer using methylene chloride as a solvent. , Schnell's viscosity formula, ie
It means a value calculated from η = 1.23 × 10 ^-4 Mv ^0.83 . The ultimate viscosity [η] is a value calculated by the following formula by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

Further, in the present invention, the polycarbonate resin may be used in combination with another thermoplastic resin. Further, for example, a polycarbonate resin is used as a copolymer with an oligomer or a polymer having a siloxane structure for the purpose of further improving flame retardancy and impact resistance; a phosphorus atom for the purpose of further improving thermal oxidation stability and flame retardancy. Copolymer with a monomer, oligomer or polymer having a dihydroxyanthraquinone structure; a copolymer with a monomer, oligomer or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermal oxidation stability; Even if it is configured as a copolymer mainly composed of a polycarbonate resin, such as a copolymer with an oligomer or a polymer having an olefin structure; a copolymer with a polyester resin oligomer or a polymer for the purpose of improving chemical resistance; good.

Further, in order to improve the appearance and fluidity of the molded product, the polycarbonate resin may contain a polycarbonate oligomer. The viscosity average molecular weight (Mv) of this polycarbonate oligomer is usually 1500 or more, preferably 2000 or more, and usually 9500 or less, preferably 9000 or less. Further, the contained polycarbonate ligomer is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Further, the polycarbonate resin 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 regenerated polycarbonate resin is preferably 80% by mass or less, and more preferably 50% by mass or less of the polycarbonate resin. Since the regenerated polycarbonate resin is likely to be deteriorated due to heat deterioration, aging deterioration, etc., if such a polycarbonate resin is used in a larger amount than the above range, the hue and mechanical properties may be deteriorated. Because it has sexual characteristics.

（一般式（１）中、Ｒは水素原子、炭素数１～８のアルキル基、炭素数１～８のアルコキシ基、ヒドロキシル基、カルボキシル基、アルキル基の炭素数が１～８のアルキルオキシカルボニル基、炭素数１～８のヒドロキシアルキル基又はアルキル基の炭素数が各々１～８のアルキルカルボニルオキシアルキル基を表す。） [Benzotriazole-based UV absorber with sesamol group (B1)]
The polycarbonate resin composition of the present invention contains a benzotriazole-based ultraviolet absorber (B1) having a sesamol group represented by the following general formula (1) (that is, a benzo [1,3] -dioxol-5-ol group). contains.

(In the general formula (1), R is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a hydroxyl group, a carboxyl group, and an alkyloxycarbonyl having an alkyl group having 1 to 8 carbon atoms. A group, a hydroxyalkyl group having 1 to 8 carbon atoms, or an alkylcarbonyloxyalkyl group having an alkyl group having 1 to 8 carbon atoms, respectively.)

Specific examples of R in the general formula (1) include hydrogen atom; methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-hexyl. A linear or branched alkyl group having 1 to 8 carbon atoms which may be substituted, such as a group, an n-octyl group, a 2-ethylhexyl group, etc .; a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, A linear or branched alkoxy group having 1 to 8 carbon atoms which may be substituted, such as an isobutoxy group, a sec-butoxy group, a tert-butoxy group, an n-hexyloxy group, an n-octyloxy group, and a 2-ethylhexyloxy group. Hydroxyl group; carboxyl group; methoxycarbonyl group, ethoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, isobutoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, n-hexyloxycarbonyl group, A linear or branched alkyloxycarbonyl group having 1 to 8 carbon atoms of an alkyl group which may be substituted, such as an n-octyloxycarbonyl group and a 2-ethylhexyloxycarbonyl group; a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group. , A hydroxybutyl group, a hydroxyhexyl group, a hydroxyoctyl group, etc., which may be substituted with a linear or branched hydroxyalkyl group having 1 to 8 carbon atoms; methylcarbonyloxymethyl group, ethylcarbonyloxymethyl group, propylcarbonyloxymethyl Group, butylcarbonyloxymethyl group, hexylcarbonyloxymethyl group, heptylcarbonyloxymethyl group, octylcarbonyloxymethyl group, methylcarbonyloxyethyl group, ethylcarbonyloxyethyl group, propylcarbonyloxyethyl group, butylcarbonyloxyethyl group, Examples thereof include linear or branched alkylcarbonyloxyalkyl groups having 1 to 8 carbon atoms in each of the alkyl groups which may be substituted, such as a hexylcarbonyloxyethyl group, a heptylcarbonyloxyethyl group, and an octylcarbonyloxyethyl group. ..

Among the above, R is preferably a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a carboxyl group, an alkyloxycarbonyl group, a hydroxyalkyl group or an alkylcarbonyloxyalkyl group. More preferably, a hydrogen atom, a methyl group, a methoxy group, an n-octyloxy group, a hydroxyl group, a carboxyl group, a methoxycarbonyl group, an n-octyloxycarbonyl group, a hydroxyethyl group, a methylcarbonyloxyethyl group and a heptylcarbonyloxyethyl group. Is.

Preferred examples of the compound represented by the general formula (1) are 6- (2H-benzotriazole-2-yl) benzo [1,3] dioxotol-5-ol, 6- (5-n-heptylcarbonyloxyethyl). -2H-benzotriazole-2-yl) benzo [1,3] dioxol-5-ol, 6- (5-isoheptylcarbonyloxyethyl-2H-benzotriazole-2-yl) benzo [1,3] dioxol- 5-ol, 6- (5-methyl-2H-benzotriazole-2-yl) benzo [1,3] dioxol-5-ol, 6- (5-methoxy-2H-benzotriazole-2-yl) benzo [ 1,3] Dioxol-5-ol, 6- (5-hydroxy-2H-benzotriazole-2-yl) benzo [1,3] Dioxol-5-ol, 6- (5-octyloxy-2H-benzotriazole) -2-Il) Benzotriazole [1,3] dioxotol-5-ol, 6- (5-carboxy-2H-benzotriazole-2-yl) Benzotriazole [1,3] Dioxotol-5-ol, 6- (5-yl) Hydroxyethyl-2H-benzotriazole-2-yl) benzo [1,3] dioxol-5-ol, 6- (5-methylcarbonyloxyethyl-2H-benzotriazole-2-yl) benzo [1,3] dioxol -5-all and the like can be mentioned.

Among these, 6- (2H-benzotriazole-2-yl) benzo [1,3] dioxotol-5-ol, 6- (5-n-heptylcarbonyloxyethyl-2H-benzotriazole-2-yl) benzo [1,3] Dioxol-5-ol, 6- (5-isoheptylcarbonyloxyethyl-2H-benzotriazole-2-yl) benzo [1,3] dioxol-5-ol are particularly preferable.

The content of the ultraviolet absorber (B1) is 0.075 to 0.15 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). When the content is less than 0.075 parts by mass, the transmittance of the obtained resin composition in the 400 to 420 nm wavelength range becomes too high, and when it exceeds 0.15 parts by mass, the transmittance in the 400 to 420 nm wavelength range is low. However, gas generation during molding becomes remarkable, and volatile substances adhere to the molded product, which significantly impairs the appearance of the product. The content of the ultraviolet absorber (B1) is preferably 0.08 part by mass or more, preferably 0.13 part by mass or less, and more preferably 0.12 part or less, based on 100 parts by mass of the polycarbonate resin (A). More preferably, it is 0.11 part by mass or less, and particularly preferably 0.10 part by mass or less.

[Ultraviolet absorber (B2)]
The polycarbonate resin composition of the present invention, in addition to the above-mentioned ultraviolet absorber (B1), is a benzotriazole-based ultraviolet absorber having no sesamole group, a triazine-based ultraviolet absorber, a malonic acid ester-based ultraviolet absorber, and a benzoxazine-based. It contains at least one UV absorber (B2) selected from UV absorbers. These ultraviolet absorbers may be used alone or in two or more kinds, and a plurality of those belonging to the kind may be used respectively.

More specific examples of the benzotriazole-based ultraviolet absorber having no cesamole group include, for example, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole, 2- (3-t-butyl). -2-Hydroxy-5-methylphenyl) -5-chloro-2H-benzotriazole, 2- [5-chloro (2H) -benzotriazole-2-yl] -4-methyl-6- (t-butyl) phenol , 2,4-Di-tert-butyl-6- (5-chlorobenzotriazole-2-yl) phenol, 2,2'-methylenebis [6- (2H-benzotriazole-2-yl) -4- (1) , 1,3,3, -tetramethylbutyl) phenol], (2- [5-chloro (2H) -benzotriazole-2-yl] -4,6-di (tert-pentyl) phenol), 3-[ 3-tert-butyl-5- (5-chloro-2H-benzotriazole-2-yl) -4-hydroxyphenyl] octylpropionate, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) )-5-Chlorobenzotriazole, 2- (2H-benzotriazole-2-yl) -6-dodecyl-4-methylphenol, 2- (2H-benzotriazole-2-yl) -p-cresol, 2-[ (2H) -benzotriazole-2-yl] -4,6-bis- (1-methyl-1-phenylethyl) phenol and the like are preferably mentioned.

Examples of malonic acid ester-based UV absorbers include dimethyl (p-methoxybenzylidene) malonate, 2- (1-arylalkylidene) malonic acid esters, and tetraethyl-2,2'-(1,4-phenylene-dimethylidene) -bismalonate. And so on.
Examples of the triazine-based ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazine-2-yl) -5-[(hexyl) oxy] -phenol and the like.
Examples of the benzoxazine-based ultraviolet absorber include 2,2'-(1,4-phenylene) bis (4H-3,1-benzoxazine-4-one) and the like.

The content of the ultraviolet absorber (B2) is 0.075 to 0.2 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A), and the content of the ultraviolet absorber (B2) and the ultraviolet absorber (B1) is contained. The mass ratio (B2) / (B1) of the quantity is more than 1 and 2 or less.
The absorption capacity of the ultraviolet absorber (B1) is insufficient by setting the mass ratio (B2) / (B1) of the content to more than 1 and 2 or less after setting the content of the ultraviolet absorber (B2) in the above range. It is possible to absorb ultraviolet rays in the vicinity of 320 nm with a smaller content, and it is possible to suppress gas generation during molding.
The content of the ultraviolet absorber (B2) is preferably 0.08 part by mass or more, more preferably 0.09 part by mass or more, and preferably 0.18 part by mass with respect to 100 parts by mass of the polycarbonate resin (A). Below, more preferably 0.175 parts by mass or less. The mass ratio (B2) / (B1) is preferably 1.2 to 1.8, more preferably 1.3 to 1.7.

[Stabilizer (C)]
The polycarbonate resin composition of the present invention contains the stabilizer (C) in an amount of 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). Examples of the stabilizer (C) include phosphorus-based stabilizers, phenol-based stabilizers, sulfur-based stabilizers, and the like.

[Phosphorus stabilizer]
By containing a phosphorus-based stabilizer, the polycarbonate resin composition of the present invention has a good hue of the polycarbonate resin composition, and further improves heat-resistant discoloration.
Any known phosphorus-based stabilizer can be used. Specific examples are phosphoric acid, phosphonic acid, phosphite, phosphinic acid, polyphosphoric acid and other phosphorus oxo acids; acidic sodium pyrophosphate, potassium pyrophosphate, acidic calcium pyrophosphate and other acidic pyrophosphate metal salts; phosphoric acid. Phosphate compounds, phosphate compounds, phosphonite compounds and the like; phosphate compounds of Group 1 or Group 2B metals such as potassium, sodium phosphate, cesium phosphate, zinc phosphate and the like; phosphite compounds are particularly preferred. By selecting the phosphite compound, a polycarbonate resin composition having higher discoloration resistance and continuous productivity can be obtained.

Here, the phosphite compound is a trivalent phosphorus compound represented by the general formula: P (OR) ₃ , and R represents a monovalent or divalent organic group.
Examples of such phosphite compounds include triphenylphosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl-phenyl) phosphite, and tris (2,4-di-tert-butylphenyl) phos. Fight, monooctyldiphenylphosphite, dioctylmonophenylphosphite, monodecyldiphenylphosphite, didecylmonophenylphosphite, tridecylphosphite, trilaurylphosphite, tristearylphosphite, distearylpentaerythritol diphosphite, Bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite, bis (2,6-di-tert-butylphenyl) octylphosphite, 2,2-methylenebis (4,6-di) -Tert-Butylphenyl) octylphosphite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene-diphosphite, 6- [3- (3-tert-butyl-hydroxy-5-methyl) Phenyl) propoxy] -2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3,2] -dioxaphosphepine and the like can be mentioned.

Among such phosphite compounds, the aromatic phosphite compound represented by the following general formula (2) or (3) is more effective because the heat-resistant discoloration property of the polycarbonate resin composition of the present invention is effectively enhanced. preferable.

（式中、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ同一であっても異なっていてもよく、炭素数６以上３０以下のアリール基を表す。）

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

（式中、Ｒ^４及びＲ^５は、それぞれ同一であっても異なっていてもよく、炭素数６以上３０以下のアリール基を表す。）

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

As the phosphite compound represented by the above formula (2), triphenylphosphine, tris (monononylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite and the like are preferable. Tris (2,4-di-tert-butylphenyl) phosphite is more preferred.

Examples of the phosphite compound represented by the above formula (3) include bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,6-di-tert-butyl). Those having a pentaerythritol diphosphite structure such as -4-methylphenyl) pentaerythritol diphosphite and bis (2,4-dicumylphenyl) pentaerythritol diphosphite are particularly preferable.

Among the phosphite compounds, the aromatic phosphite compound represented by the above formula (3) is more preferable because it has a better hue.
The phosphorus-based stabilizer may contain one kind or two or more kinds in any combination and ratio.

The content of the phosphorus-based stabilizer is 0.01 to 0.5 parts by mass, preferably 0.02 parts by mass or more, and more preferably 0.03 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). The above is more, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, still more preferably 0.2 parts by mass or less. If the content of the phosphorus-based stabilizer (C) is less than 0.01 parts by mass, the hue and heat-resistant discoloration will be insufficient, and if it exceeds 0.5 parts by mass, the heat-resistant discoloration will only worsen. Not only that, but also the wet and heat stability is reduced.

[Phenolic stabilizer]
The polycarbonate resin composition of the present invention may contain a phenolic stabilizer as a stabilizer. Examples of the phenol-based stabilizer include hindered phenol-based antioxidants. Specific examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and 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''-(mesitylen-2,4,6-triyl) tri -P-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylene bis (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- Examples thereof include 2-ylamino) phenol and 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate.

Of these, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate are preferable. .. Specific examples of such phenolic antioxidants include, for example, "Irganox 1010" and "Irganox 1076" manufactured by BASF, "ADEKA STAB AO-50" and "ADEKA STAB AO-60" manufactured by ADEKA. Can be mentioned.
The phenolic stabilizer may contain one kind or two or more kinds in any combination and ratio.

The content of the phenolic stabilizer is 0.01 to 0.5 parts by mass, preferably 0.02 parts by mass or more, and more preferably 0.03 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). The above is more, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, still more preferably 0.2 parts by mass or less. If the content of the phenolic stabilizer is less than the lower limit of the above range, the effect as the phenolic stabilizer may be insufficient, and the content of the phenolic stabilizer exceeds the upper limit of the above range. In that case, the effect may reach a plateau and become uneconomical.

Phosphorus-based stabilizers and phenol-based stabilizers may be used in combination. In that case, the total content of the phosphorus-based stabilizer and the phenol-based stabilizer is 0.01 to 0.5 parts by mass, preferably 0.02 parts by mass or more with respect to 100 parts by mass of the polycarbonate resin (A). , More preferably 0.03 parts by mass or more, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, still more preferably 0.2 parts by mass or less.

[Sulfur stabilizer]
Examples of the sulfur-based stabilizer include dilauryl-3,3'-thiodipropionic acid ester, ditridecyl-3,3'-thiodipropionic acid ester, dimyristyl-3,3'-thiodipropionic acid ester, and distearyl. -3,3'-thiodipropionic acid ester, laurylstearyl-3,3'-thiodipropionic acid ester, pentaerythritol tetrakis (3-laurylthiopropionate), bis [2-methyl-4- (3-) Laurylthiopropionyloxy) -5-tert-butylphenyl] sulfide, octadecyldisulfide, mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, 1,1'-thiobis (2-naphthol) and the like can be mentioned.

Of the above, pentaerythritol tetrakis (3-laurylthiopropionate) is preferable. Specific examples of such a sulfur-based stabilizer include "ADEKA STUB AO-412S" manufactured by ADEKA Corporation.

The content of the sulfur-based stabilizer is 0.01 to 0.5 parts by mass, preferably 0.02 parts by mass or more, and more preferably 0.03 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). The above is more, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, still more preferably 0.2 parts by mass or less. If the content of the sulfur-based stabilizer is less than the lower limit of the above range, the effect as the sulfur-based stabilizer may be insufficient, and the content of the sulfur-based stabilizer exceeds the upper limit of the above range. In that case, the effect may reach a plateau and become uneconomical.

[Additives, etc.]
The polycarbonate resin composition of the present invention has other additives other than those described above, such as a mold release agent, a fluorescent whitening agent, a pigment, a dye, a flame retardant, an impact resistance improver, an antistatic agent, a plasticizer, and a compatibilization agent. It can contain additives such as agents and resins other than polycarbonate resins.
These additives or other resins may be used alone or in combination of two or more.
However, when a resin other than the polycarbonate resin (A) is contained, the content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the polycarbonate resin (A). Further, it is preferably 5 parts by mass or less, particularly preferably 3 parts by mass or less.

[Manufacturing method of polycarbonate resin composition]
The method for producing the polycarbonate resin composition of the present invention is not limited, and a known method for producing the polycarbonate resin composition can be widely adopted, and the polycarbonate resin (A), the ultraviolet absorber (B1), the ultraviolet absorber (B2), and phosphorus can be widely adopted. After premixing the system stabilizer (C) and other components to be blended as needed using various mixers such as a tumbler and a henschel mixer, a Banbury mixer, a roll, a brabender, and a uniaxial kneading extrusion are used. Examples thereof include a method of melt-kneading with a mixer such as a machine, a twin-screw kneading extruder, or a kneader. The temperature of melt-kneading is not particularly limited, but is usually in the range of 240 to 320 ° C.

The polycarbonate resin composition of the present invention can produce various molded products by molding pellets obtained by pelletizing the above-mentioned polycarbonate resin composition by various molding methods. Further, the resin melt-kneaded by an extruder can be directly molded into a molded product without passing through pellets.

Since the polycarbonate resin composition of the present invention has excellent cutting performance in the wavelength range of 400 to 420 nm, a molded product having a thickness of 2 mm obtained by molding this polycarbonate resin composition has a wavelength of 420 nm in accordance with JIS K7105. The transmittance measured in 1 is preferably 25% or less. The transmittance is more preferably 10% or less, further preferably 5% or less, and particularly preferably 1% or less. If the transmittance at a wavelength of 420 nm exceeds 25%, it is insufficient as a material for sunglasses lenses and the like aiming at cutting in the wavelength range of 400 to 420 nm.

Further, in the polycarbonate resin composition of the present invention, the transmittance measured at a wavelength of 320 nm in accordance with JIS K7105 for a molded product having a thickness of 2 mm obtained by molding this polycarbonate resin composition is preferably 0. It is less than 5.5%. The transmittance is more preferably 0.3% or less, further preferably 0.1% or less.

In the present invention, the maximum absorption wavelength of the ultraviolet absorbers (B1) to (B2) is the absorbance of the polycarbonate resin containing 0.005% by mass of the ultraviolet absorber according to the following formula (1) in a flat plate-shaped molded product. Therefore, it is defined as the maximum absorption wavelength of the absorption curve obtained by subtracting the absorbance of a flat plate-shaped molded product having the same shape and the same thickness as the same polycarbonate resin containing no ultraviolet absorber.
[Asorbance of Polycarbonate Resin Containing 0.005% by Mass of UV Absorbant]-[Asorbance of Polycarbonate Resin Only] ... (1)
It is considered in principle that the maximum absorption wavelength defined in this way does not change depending on the thickness of the flat-plate molded product used, but in the present invention, it is preferable to compare with a thickness of 2 mm.
Further, the specific conditions and the like of the method for measuring and determining the maximum absorption wavelength are as described in the examples.

The molded product obtained from the polycarbonate resin composition of the present invention has excellent cutability of light having a wavelength of 400 to 420 nm, which is on the more visible light side, in addition to ultraviolet light, and has no problem of gas generation during molding. It has various excellent mechanical and thermal properties of the polycarbonate resin. Therefore, the application can be widely and suitably used for applications where deterioration due to ultraviolet rays is a concern, and examples thereof include sheets, films, miscellaneous goods, home appliance parts, automobile parts, building materials, hollow containers, and the like. More specifically, for example, eyeglass lenses, sunglasses lenses, goggles (for skis, etc.), protective glasses, protective facets, etc., roof panels such as arcades, indoor pools, carports, sun roofs, signal lights, sound insulation walls, automobile sides, etc. A window, a rear window, a solar cell housing, a street light cover and the like are preferably mentioned.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not construed as being limited to the following examples.

The raw materials and evaluation methods used in the following Examples and Comparative Examples are as follows.

In Table 1 above, the maximum absorption wavelength of the ultraviolet absorber is the absorbance A _λ of the polycarbonate resin composition shown in Table 1 containing 0.005% of each ultraviolet absorber and does not contain the ultraviolet absorber. It is the maximum absorption wavelength obtained from the absorption curve of the absorbance (A _λ − A _λ0 ) obtained by determining the absorbance A _λ0 of the polycarbonate resin shown in Table 1 above and subtracting the absorbance A _λ0 from the absorbance A _λ . The absorbance A _λ and the absorbance A _{λ 0} were measured in the same manner as described in [Measurement of Transmittance and Absorbance] below.

(Examples 1 to 13, Comparative Examples 1 to 12)
[Manufacturing of resin composition pellets]
Each component listed in Table 1 above is blended in the proportions (parts by mass) shown in Tables 2 to 3 below, mixed in a tumbler for 20 minutes, and then a single-screw extruder with a vent (Tanabe Plastic) having a screw diameter of 40 mm. By melt-kneading at a cylinder temperature of 280 ° C. using “VS-40” manufactured by Kikai Co., Ltd., pellets of a polycarbonate resin composition were obtained by strand cutting.

[Measurement of transmittance and absorbance]
The obtained pellets are dried at 120 ° C. for 5 hours with a hot air circulation type dryer, and then molded with an injection molding machine (“SE50DUZ” manufactured by Sumitomo Heavy Industries, Ltd.) at a resin temperature of 280 ° C. and a mold temperature of 80 ° C. Under the condition of a cycle of 30 seconds, a three-stage stepped flat plate-shaped test piece having a width of 50 mm and a length of 90 mm and a thickness of 1 mm, 2 mm and 3 mm was formed.
In accordance with JIS K7105, the transmittance and absorbance of the 2 mm thick portion of the stepped flat plate test piece were measured using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation).
The transmittances (unit:%) at 420 nm, 380 nm and 320 nm are shown in Table 2 and below.

[Evaluation of gas generation during molding]
The pellets obtained above are dried at 120 ° C. for 5 hours, and then the cylinder temperature is adjusted using an injection molding machine (“SE18DUZ” manufactured by Sumitomo Heavy Industries, Ltd.) and a drop mold shown in FIG. 100 shot injection molding was performed under the conditions of 320 ° C., molding cycle 10 seconds, and mold temperature 80 ° C., and the state of stains due to white deposits generated on the metal mirror surface on the fixed side of the mold after completion was compared with Comparative Example 4. Based on the following criteria, the evaluation was visually evaluated and used as the evaluation of gas generation during molding.
A: The amount of deposits on the mold is much smaller than that after 100-shot molding in Comparative Example 4, and the mold contamination resistance is extremely good.
B: The amount of deposits on the mold is less than that after 100-shot molding in Comparative Example 4, but the mold contamination resistance is slightly observed.
C: The mold deposits are at the same level as the state after 100-shot molding in Comparative Example 4, and mold contamination is observed.
D: The amount of deposits on the mold is larger than that after 100-shot molding in Comparative Example 4, and the mold is significantly contaminated.

The drop mold of FIG. 1 is a mold designed so that the resin composition is introduced from the gate G and the generated gas easily collects in the tip P portion. The width of the gate G is 1 mm and the thickness is 1 mm. In FIG. 1, 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.
The above evaluation results are shown in Tables 2 and 3 below.

The molded product obtained from the polycarbonate resin composition of the present invention has excellent cutability of light having a wavelength of 400 to 420 nm, which is on the more visible light side, in addition to ultraviolet light, and has no problem of gas generation during molding. It has various excellent mechanical and thermal properties of the polycarbonate resin, can be suitably used for applications where deterioration due to ultraviolet rays is a concern, and has high industrial utility.

Claims (3)

With respect to 100 parts by mass of the polycarbonate resin (A), 0.075 to 0.15 parts by mass of the benzotriazole-based ultraviolet absorber (B1) having a sesamole group represented by the following general formula (1) and having no sesamole group. At least one UV absorber (B2) selected from benzotriazole-based UV absorbers, triazine-based UV absorbers, malonic acid ester-based UV absorbers, and benzoxazine-based UV absorbers (B2) 0.075 to 0.175 parts by mass. , The stabilizer (C) is contained in an amount of 0.01 to 0.5 parts by mass, and the mass ratio (B2) / (B1) of the contents of the ultraviolet absorber (B2) and (B1) is more than 1 and 2 or less . ,
A polycarbonate resin composition having a transmittance of 25% or less measured at a wavelength of 420 nm in a molded product having a thickness of 2 mm in accordance with JIS K7105 .

(In the general formula (1), R is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a hydroxyl group, a carboxyl group, and an alkyloxycarbonyl having an alkyl group having 1 to 8 carbon atoms. A group, a hydroxyalkyl group having 1 to 8 carbon atoms, or an alkylcarbonyloxyalkyl group having an alkyl group having 1 to 8 carbon atoms, respectively.) The polycarbonate resin composition according to claim 1, wherein the molded product having a thickness of 2 mm and having a transmittance of 0.5% or less measured at a wavelength of 320 nm according to JIS K7105. A molded product of the polycarbonate resin composition according to claim 1 or 2 .

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