JP6746533B2 - Polycarbonate resin composition and optical molded article - Google Patents

Description

The present invention relates to a polycarbonate resin composition and an optical molded article.

BACKGROUND ART Polycarbonate resins have been conventionally used for molded products such as light guide plates, various lenses, and name plates, because they are excellent in impact resistance, heat resistance, transparency, and the like.

For example, in Patent Document 1, an aromatic polycarbonate resin composition for a light guide plate, in which a stabilizer and a release agent are mixed with an aromatic polycarbonate resin in which a ratio of a weight average molecular weight and a number average molecular weight is defined in a specific range Is disclosed.

Patent Document 2 discloses a polycarbonate resin composition for optical molded articles in which polystyrene and one type of phosphorus-based antioxidant are mixed with a polycarbonate resin.

In addition, for example, as disclosed in Patent Documents 3 to 6, various resin compositions in which a polycarbonate resin is used in combination with other materials to obtain excellent light transmittance and improve the brightness of the optical member are proposed. Has been done.

However, the polycarbonate resin compositions disclosed in Patent Documents 3 to 6 are required as a material for a light guide plate in recent years (especially, a requirement that light transmittance does not decrease even when molding is performed at high temperature for thin-wall molding). ) Is not fully satisfactory.

JP, 2007-204737, A JP, 09-020860, A JP, 2011-133647, A JP, 11-158364, A JP 2001-215336 A JP 2004-051700 A

INDUSTRIAL APPLICABILITY The present invention does not impair properties such as heat resistance and mechanical strength originally possessed by a polycarbonate resin, is excellent in thermal stability, has a high light transmittance, and is excellent in light transmittance even when molded at high temperature. A polycarbonate resin composition is provided.

As a result of earnest studies to solve such problems, the present inventors have found that a polycarbonate resin (A) containing a melt viscosity modifier (B) and a phosphite compound (C) In the composition, by making the ratio of the melt viscosity of the polycarbonate resin composition and the melt viscosity of the polycarbonate resin (A) contained therein to satisfy a value in a specific range, the light transmittance decreases even when molded at high temperature. The present invention has been completed by finding that a polycarbonate resin composition having good hue and brightness can be obtained.

That is, the present invention is based on 100 parts by weight of the polycarbonate resin (A), 0.005-3.0 parts by weight of the melt viscosity modifier (B) and 0.005-1. A polycarbonate resin composition containing 0 parts by weight, wherein the melt viscosity at a measurement temperature of 220° C. and a shear rate of 10 sec ⁻¹ is η, the melt viscosity η1 of the polycarbonate resin composition and the polycarbonate resin (A) are the ratio .eta.1 / .eta.2 melt viscosity .eta.2 is satisfies 0.45 ≦ η1 / η2 ≦ 0.95, a melt viscosity modifier (B) is, it polyether derivative der represented by the following general formula (1) _{, HO- (CH 2 CH 2 CH} 2 CH 2 O) m (CH 2 CH 2 CH (CH 3) CH 2 O) n-H ( wherein, m and n are each independently of 3-60 an integer, m + n is a compound represented by the indicating.) an integer of _{8~90, HO- (CH 2 CH 2} CH 2 CH 2 O) m- (CH (CH 3) CH 2 O) nH ( m / n molar ratio: 45.7 / 54.3 number average molecular weights expressed as) is Ri polyether derivatives der neither the compounds wherein 1000, weight average molecular weight of the polyether derivative is 1000 to 4000 Is what is.
General formula (1):
RO-(X-O)m(Y-O)n-R' (1)
(In the formula, R and R′ each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X is an alkylene group having 4 carbon atoms, and Y is a branched alkylene group having 3 to 5 carbon atoms. In the group, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.)

The polycarbonate resin composition of the present invention does not impair the properties such as heat resistance and mechanical strength originally possessed by the polycarbonate resin, is excellent in thermal stability and weather resistance, and has a light transmittance even when molded at high temperature. It is an excellent one. Therefore, even for a thin light guide plate having a thickness of, for example, about 0.3 mm, there is little possibility that the hue will change and the appearance will be deteriorated, and the resin itself will not be deteriorated after high temperature molding. high.

The embodiments will be described in detail below. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters and repeated description of substantially the same configuration may be omitted. This is for avoiding unnecessary redundancy in the following description and for facilitating understanding by those skilled in the art.

It should be noted that the inventors provide the following explanations for those skilled in the art to fully understand the present invention, and are not intended to limit the subject matter described in the claims by these.

The polycarbonate resin composition used in the present invention is a blend of the polycarbonate resin (A), the melt viscosity modifier (B), and the phosphite ester compound (C). The polycarbonate resin composition used in the present invention may contain other components, if necessary.

The polycarbonate resin (A) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonic acid ester such as diphenyl carbonate. It is united. A typical example is a polycarbonate resin produced from 2,2-bis(4-hydroxyphenyl)propane (bisphenol A).

Examples of the dihydroxydiaryl compound include bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, in addition to bisphenol A. 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxyphenyl-3-methylphenyl)propane, 1,1-bis(4-hydroxy) -3-tert-Butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2- Bis(hydroxyaryl)alkanes such as bis(4-hydroxy-3,5-dichlorophenyl)propane; 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, etc. Bis(hydroxyaryl)
Cycloalkanes; dihydroxydiaryl ethers such as 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dimethyldiphenylether; dihydroxydiarylsulfides such as 4,4'-dihydroxydiphenylsulfide; Dihydroxy diaryl sulfoxides such as 4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'- Examples thereof include dihydroxydiaryl sulfones such as dimethyldiphenyl sulfone, and these may be used alone or in admixture of two or more. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4′-dihydroxydiphenyl and the like may be mixed and used.

Further, the dihydroxydiaryl compound may be mixed with, for example, a phenol compound having a valence of 3 or more shown below.

Examples of the trivalent or higher phenol compound include phloroglucin, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene, 2,4,6-dimethyl-2,4,6. -Tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzol, 1,1,1-tri-(4-hydroxyphenyl)-ethane and 2,2- Examples thereof include bis-[4,4-(4,4'-dihydroxydiphenyl)-cyclohexyl]-propane.

The viscosity average molecular weight of the polycarbonate resin (A) is preferably 10,000 to 100,000, and more preferably 12,000 to 30,000. In addition, when manufacturing such a polycarbonate resin (A), a molecular weight regulator, a catalyst, etc. can be used as needed.

The melt viscosity modifier (B) used in the present invention behaves like a kind of lubricant to reduce the shear viscosity (shear viscosity) of the polycarbonate resin when the polycarbonate resin composition is molded and processed, It means that it has a function of suppressing excessive heat generation from shearing, and further, reducing or suppressing heat generation in the polycarbonate resin.

As the melt viscosity modifier (B), when the melt viscosity at a measurement temperature of 220° C. and a shear rate of 10 sec ⁻¹ is η, the ratio η1 of the melt viscosity η1 of the polycarbonate resin composition and the melt viscosity η2 of the polycarbonate resin (A) is η1. There is no particular limitation as long as /η2 can be adjusted so as to satisfy 0.45≦η1/η2≦0.95, but typically, the following general formula (1) is used. The polyether derivative etc. which are represented are mentioned. In addition, silicone compounds, glycerin compounds, pentaerythritol compounds, etc. may be mentioned.

General formula (1):
RO-(X-O)m(Y-O)n-R' (1)
(In the formula, R and R′ each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X is an alkylene group having 2 to 4 carbon atoms, and Y is an alkyl group having 3 to 5 carbon atoms. In the branched alkylene group, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.)

As the polyether derivative represented by the general formula (1), a modified glycol composed of a tetramethylene glycol unit and a 1-ethylethylene glycol unit (for example, HO-(CH ₂ CH ₂ CH ₂ CH ₂ O) ₂₄ (CH _{2 CH (C 2 H 5) O} ) 13 -H , etc.), for example, manufactured by NOF CORPORATION of DCD-2000 (weight average molecular weight 2000) is commercially available as such. The weight average molecular weight of the polyether derivative represented by the general formula (1) is 1,000.
It is preferably ˜4000.

Further, as the polyether derivative, among the polyether derivatives represented by the general formula (1), the polyether derivative represented by the following general formula (2), general formula (3) or general formula (4) is preferable. Is.
General formula (2):
_{HO- (CH 2 CH 2 CH 2} CH 2 O) m (CH 2 CH 2 CH (CH 3) CH 2 O) n-H (2)
(In the formula, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.)

As the polyether derivative represented by the general formula (2), a modified glycol composed of a tetramethylene glycol unit and a 2-methyltetramethylene glycol unit (for example, HO-(CH ₂ CH ₂ CH ₂ CH ₂ O) ₂₂ (CH _{2 CH 2 CH (CH 3)} CH 2 O) 5 -H , etc.) can be mentioned, for example, Hodogaya Chemical Co., Ltd. PTG-L1000 (weight average molecular weight 1000), PTG-L2000 (weight average molecular weight 2000 ), or PTG-L3000 (weight average molecular weight 3000) and the like. The weight average molecular weight of the polyether derivative represented by the general formula (2) is preferably 1000 to 4000.

General formula (3):
_{C 4 H 9 O- (CH 2} CH 2) m (CH 2 CH (CH 3) O) n-H (3)
(In the formula, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.)

As the polyether derivative represented by the general formula (3), a modified glycol composed of an ethylene glycol unit and a propylene glycol unit (for example, C ₄ H ₉ O—(CH ₂ CH ₂ O) ₂₁ (CH ₂ CH(CH ₃ ) _O) 14 -H and _{C 4 H 9 O- (CH 2} CH 2 O) 30 (CH 2 CH (CH 3) O) 30 -H , etc.) are preferable, for example, Unilube 60MB-26I (weight average A molecular weight of 1700) and Unilube 50MB-72 (weight average molecular weight of 3000) are commercially available. The weight average molecular weight of the polyether derivative represented by the general formula (3) is preferably 1000 to 4000.

General formula (4):
_{HO- (CH 2 CH 2 O)} m (CH 2 CH (CH 3) O) n-H (4)
(In the formula, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.)

As the polyether derivative represented by the general formula (4), a modified glycol composed of an ethylene glycol unit and a propylene glycol unit (for example, HO—(CH ₂ CH ₂ O) ₁₇ (CH ₂ CH(CH ₃ )O) ₁₇ -H is preferable, and for example, Unilube 50DE-25 (weight average molecular weight 1750) is commercially available, etc. The weight average molecular weight of the polyether derivative represented by the general formula (4) is 1000 to 4000. Is preferred.

Up to now, it has been attempted to add a linear polyoxyalkylene glycol to improve the light transmittance of the polycarbonate resin, but since the polyoxyalkylene glycol has insufficient heat resistance, When a polycarbonate resin composition containing an alkylene glycol is molded at high temperature, the brightness and light transmittance of the molded product decrease. On the other hand, the melt viscosity modifier such as the polyether derivative represented by the general formula (1) is a bifunctional random copolymer, has high heat resistance, and has the general formula (1). A molded product obtained by molding a polycarbonate resin composition containing a specific polyether derivative shown at a high temperature has high brightness and high light transmittance.

Further, since the melt viscosity modifier (B) used in the present invention has an appropriate lipophilicity, it is also excellent in compatibility with the polycarbonate resin (A). The transparency of the molded product obtained from the blended polycarbonate resin composition is also improved. The weight average molecular weight of the polyether derivative used in the melt viscosity modifier (B) is preferably 1000 to 4000, more preferably 2000 to 3000. When the weight average molecular weight of the polyether derivative is 1000 to 4000, a sufficient effect of improving the light transmittance can be expected, and there is no fear that the light transmittance will decrease without increasing the clouding ratio.

The amount of the polyether derivative is 0.005 to 3.0 parts by weight, preferably 0.1 to 1.5 parts by weight, and further 0.3 to 1. 1 part by weight with respect to 100 parts by weight of the polycarbonate resin (A). It is preferably 2 parts by weight. When the amount of the polyether derivative is less than 0.005 part by weight, the effect of improving the light transmittance and the hue is insufficient. On the other hand, when the amount of the polyether derivative exceeds 3.0 parts by weight, the clouding rate increases and the light transmittance decreases.

The polycarbonate resin composition of the present invention contains a phosphite compound (C) together with a melt viscosity modifier (B) such as a specific polyether derivative. Thus, by simultaneously mixing the melt viscosity modifier (B) and the phosphite compound (C), it is possible to prevent the shear heat insulation of the polycarbonate resin composition from occurring as much as possible, and the polycarbonate resin (A) It is possible to obtain a polycarbonate resin composition in which properties such as heat resistance and mechanical strength originally possessed by (1) are not impaired and the light transmittance is improved even when molded at high temperature.

As the phosphite compound (C) used in the present invention, for example, a compound represented by the following general formula (5) is particularly suitable.

（式中、Ｒ^１は、炭素数１〜２０のアルキル基を示し、ａは、０〜３の整数を示す）

(In the formula, R ¹ represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 0 to 3)

In the general formula (5), R ¹ is an alkyl group having 1 to 20 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms.

Examples of the compound represented by the general formula (5) include triphenyl phosphite, tricresyl phosphite, tris(2,4-di-t-butylphenyl)phosphite, and trisnonylphenyl phosphite. To be Among these, tris(2,4-di-t-butylphenyl)phosphite is particularly preferable, and for example, it is commercially available as Irgafos 168 manufactured by BASF (“Irgafos” is a registered trademark of BSF Society of Europe). Is available at.

Examples of the phosphite ester compound include compounds represented by the following general formula (6), in addition to the compounds represented by the general formula (5).

（式中、Ｒ^２、Ｒ^３、Ｒ^５及びＲ^６は、それぞれ独立して、水素原子、炭素数１〜８のアルキル基、炭素数５〜８のシクロアルキル基、炭素数６〜１２のアルキルシクロアルキル基、炭素数７〜１２のアラルキル基又はフェニル基を示す。Ｒ^４は、水素原子又は炭素数１〜８のアルキル基を示す。Ｘは、単結合、硫黄原子又は式：−ＣＨＲ^７−（ここで、Ｒ^７は、水素原子、炭素数１〜８のアルキル基又は炭素数５〜８のシクロアルキル基を示す）で表される基を示す。Ａは、炭素数１〜８のアルキレン基又は式：＊−ＣＯＲ^８−（ここで、Ｒ^８は、単結合又は炭素数１〜８のアルキレン基を示し、＊は、酸素側の結合手であることを示す）で表される基を示す。Ｙ及びＺは、いずれか一方がヒドロキシル基、炭素数１〜８のアルコキシ基又は炭素数７〜１２のアラルキルオキシ基を示し、もう一方が水素原子又は炭素数１〜８のアルキル基を示す。）

^{(Wherein, R 2, R 3, R} 5 and ^{R 6} are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, cycloalkyl group having 5 to 8 carbon atoms, 6 to 12 carbon atoms An alkylcycloalkyl group, an aralkyl group having 7 to 12 carbon atoms or a phenyl group is shown, R ⁴ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, X is a single bond, a sulfur atom or a formula: —CHR. ^7- (Here, R< ⁷ > shows a hydrogen atom, a C1-C8 alkyl group, or a C5-C8 cycloalkyl group.) A is C1-C8. Or an alkylene group of the formula: *-COR ⁸ — (wherein R ⁸ represents a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond on the oxygen side). One of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other is a hydrogen atom or a C 1 to 8 carbon atom. Indicates an alkyl group.)

In the general formula (6), R ² , R ³ , R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or 6 carbon atoms. To 12 alkylcycloalkyl groups, aralkyl groups having 7 to 12 carbon atoms or phenyl groups.

Here, examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group. Group, t-pentyl group, i-octyl group, t-octyl group, 2-ethylhexyl group and the like. Examples of the cycloalkyl group having 5 to 8 carbon atoms include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. Examples of the alkylcycloalkyl group having 6 to 12 carbon atoms include 1-methylcyclopentyl group, 1-methylcyclohexyl group, 1-methyl-4-i-propylcyclohexyl group and the like. Examples of the aralkyl group having 7 to 12 carbon atoms include benzyl group, α-methylbenzyl group, α,α-dimethylbenzyl group and the like.

It is preferable that R ² , R ³ and R ⁵ are each independently an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms or an alkylcycloalkyl group having 6 to 12 carbon atoms. .. Particularly, it is preferable that R ² and R ⁵ are each independently a t-alkyl group such as t-butyl group, t-pentyl group, t-octyl group, cyclohexyl group or 1-methylcyclohexyl group. In particular, R ³ is a carbon number such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, t-pentyl group. It is preferably an alkyl group of 1 to 5, more preferably a methyl group, a t-butyl group or a t-pentyl group.

R ⁶ is preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms, and a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group. , N-butyl group, i-butyl group, sec-butyl group, t-butyl group, t-pentyl group and the like, and more preferably an alkyl group having 1 to 5 carbon atoms.

In the general formula (6), R ⁴ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include the alkyl groups exemplified in the description of R ² , R ³ , R ⁵ and R ⁶ above. In particular, R ⁴ is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group.

In the general formula (6), X represents a single bond, a sulfur atom or a group represented by the formula: —CHR ⁷ —. Here, R ⁷ in the formula: —CHR ⁷ — represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms and the cycloalkyl group having 5 to 8 carbon atoms include the alkyl group and cycloalkyl group exemplified in the description of R ² , R ³ , R ⁵ and R ⁶ , respectively. To be Particularly, X is a single bond, a methylene group, or a methylene group substituted with a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group or the like. Is preferably present, and more preferably a single bond.

In the general formula (6), A represents an alkylene group having 1 to 8 carbon atoms or a group represented by the formula: *-COR ⁸ —. Examples of the alkylene group having 1 to 8 carbon atoms include methylene group, ethylene group, propylene group, butylene group, pentamethylene group, hexamethylene group, octamethylene group, 2,2-dimethyl-1,3-propylene group and the like. And a propylene group is preferable. R ⁸ in the formula: *-COR ⁸ — represents a single bond or an alkylene group having 1 to 8 carbon atoms. Examples of the alkylene group having 1 to 8 carbon atoms which represents R ⁸ include the alkylene groups exemplified in the description of A above. R ⁸ is preferably a single bond or an ethylene group. Further, * in the formula: *-COR ⁸ — is a bond on the oxygen side, and indicates that the carbonyl group is bonded to the oxygen atom of the phosphite group.

In the general formula (6), one of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other one is a hydrogen atom or 1 to 12 carbon atoms. 8 represents an alkyl group. Examples of the alkoxy group having 1 to 8 carbon atoms include methoxy group, ethoxy group, propoxy group, t-butoxy group, pentyloxy group and the like. Examples of the aralkyloxy group having 7 to 12 carbon atoms include benzyloxy group, α-methylbenzyloxy group and α,α-dimethylbenzyloxy group. Examples of the alkyl group having 1 to 8 carbon atoms include the alkyl groups exemplified in the description of R ² , R ³ , R ⁵ and R ⁶ above.

Examples of the compound represented by the general formula (6) include 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl). Propoxy]dibenzo[d,f][1,3,2]dioxaphosphepine, 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-2,4,8 , 10-Tetra-t-butyldibenzo[d,f][1,3,2]dioxaphosphepine, 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy] -4,8-Di-t-butyl-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin, 6-[3-(3,5-di-t] -Butyl-4-hydroxyphenyl)propionyloxy]-4,8-di-t-butyl-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin. To be Among these, 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4) is used when the obtained polycarbonate resin composition is used in a field where optical properties are particularly required. -Hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosphepine is preferable, and examples thereof include Sumilizer GP manufactured by Sumitomo Chemical Co., Ltd. (“Sumilizer”). Is a registered trademark) and is commercially available.

Examples of the phosphite compound (C) include compounds represented by the general formula (5) and compounds represented by the general formula (6), and, for example, compounds represented by the general formula (7). The compound described can be preferably used.

（式中、Ｒ^９及びＲ^１０は、それぞれ独立して、炭素数１〜２０のアルキル基又はアルキル基で置換されていてもよいアリール基を示し、ｂ及びｃは、それぞれ独立して、０〜３の整数を示す。）

(In the formula, R ⁹ and R ¹⁰ each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group, and b and c each independently represent 0 or Indicates an integer of 3).

As the compound represented by the general formula (7), for example, ADEKA STAB PEP-36 (“ADEKA STAB” is a registered trademark) manufactured by ADEKA Corporation is commercially available.

The amount of the phosphite ester-based compound (C) is 0.005 to 1.0 part by weight, preferably 0.01 to 0.5 part by weight, based on 100 parts by weight of the polycarbonate resin (A). It is preferably 0.02 to 0.1 part by weight. When the amount of the phosphite compound (C) is less than 0.005 part by weight, the effect of improving the light transmittance and the hue is insufficient. Conversely, when the amount of the phosphite compound (C) exceeds 1.0 part by weight, the effect of improving the light transmittance and the hue is insufficient.

In addition to the above components, the polycarbonate resin composition according to the embodiment, for example, obtained by molding a polycarbonate resin composition an ultraviolet absorber that is a component that further improves the weather resistance of the obtained polycarbonate resin composition. It can be appropriately used depending on the intended use of the molded product.

Examples of the ultraviolet absorber include, for example, benzotriazole-based compounds, triazine-based compounds, benzophenone-based compounds, oxalic anilide-based compounds and the like, which are usually added to polycarbonate resins alone or in combination of two or more thereof. Can be used.

Examples of the benzotriazole compound include, for example, 2-(2-hydroxy-5-t-octylphenyl)benzotriazole and 2-(3-tert-butyl-2-hydroxy-5-methylphenyl) as the benzotriazole compound. -5-chloro-2H-benzotriazole, 2-(3,5-di-tert-pentyl-2-hydrophenyl)-2H-benzotriazole, 2-(2H-benzotriazole-2-yl)-4-methyl-6-( 3,4,5,6-Tetrahydrophthalimidylmethyl)phenol, 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzyl). '-Hydroxy-3,5-di(1,1-dimethylmethylbenzyl)phenyl]-2H-benzotriazole,2,2'-Methylenbis[6-(2H-benzotriazol-2-yl)4-(1,1,3,3) 3-tetramethylbutyl)phenol] and the like. Of these, 2-(2-hydroxy-5-t-octylphenyl)benzotriazole and the like are particularly preferable, and examples thereof include TINUVIN 329 (TINUVIN is a registered trademark) manufactured by BASF, and Seesorb manufactured by Cypro Kasei Co., Ltd. 709, Chemisorb 79 manufactured by Chemipro Kasei Co., Ltd., and the like are commercially available.

Examples of the triazine-based compound include 2,4-diphenyl-6-(2-hydroxyphenyl-4-hexyloxyphenyl)1,3,5-triazine and 2-[4,6-bis(2,4-dimethyl). Phenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)phenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[( Hexyl)oxy]phenol and the like, and for example, TINUVIN 1577 manufactured by BASF and the like are commercially available.

As the oxalic acid anilide-based compound, for example, Sanduvor VSU manufactured by Clariant Japan KK or the like is commercially available.

Examples of the benzophenone-based compound include 2,4-dihydroxybenzylzophenone and 2-hydroxy-4-n-octoxybenzophenone.

The amount of the ultraviolet absorber is 0 to 1.0 part by weight, preferably 0 to 0.5 part by weight, based on 100 parts by weight of the polycarbonate resin (A). When the amount of the ultraviolet absorber (D) exceeds 1.0 part by weight, the initial hue of the obtained polycarbonate resin composition may decrease. Further, particularly when the amount of the ultraviolet absorber (D) is 0.1 part by weight or more, the effect of further improving the weather resistance of the polycarbonate resin composition is greatly exerted.

Furthermore, in the polycarbonate resin composition according to the embodiment, for example, other antioxidants, colorants, release agents, softening agents, antistatic agents, impact modifiers, within a range that does not impair the effects of the present invention. Various additives such as the above, polymers other than the polycarbonate resin (A), and the like may be appropriately blended.

The method for producing the polycarbonate resin composition is not particularly limited, and the polycarbonate resin (A), the melt viscosity adjusting agent (B), and the phosphite compound (C), and if necessary, the various additives and the polycarbonate resin For polymers and the like other than (A), the type and amount of each component are appropriately adjusted, and a method of mixing these with a known mixer such as a tumbler or a ribbon blender or a method of melt-kneading with an extruder is available. Can be mentioned. By these methods, pellets of the polycarbonate resin composition can be easily obtained.

The shape and size of pellets of the polycarbonate resin composition obtained as described above are not particularly limited, and may be any shape and size that a general resin pellet has. For example, the shape of the pellet may be an elliptic cylinder, a cylinder, or the like. The size of the pellet is preferably about 2 to 8 mm, and in the case of an elliptic column, the major axis of the ellipse in section is about 2 to 8 mm and the minor axis is about 1 to 4 mm. In the case of a columnar shape, it is preferable that the diameter of the cross section circle is about 1 to 6 mm. Each of the obtained pellets may have such a size, all the pellets forming the pellet aggregate may have such a size, and the average value of the pellet aggregate may be It may have any size and is not particularly limited.

The polycarbonate resin composition of the present invention is obtained by molding the polycarbonate resin composition obtained as described above.

The method for producing the polycarbonate resin composition of the present invention is not particularly limited, and examples thereof include a method of molding the polycarbonate resin composition by a known injection molding method, compression molding method, or the like.

The embodiments have been described above as examples of the present invention. However, the technique of the present invention is not limited to this, and can be applied to the embodiment in which changes, replacements, additions, omissions, etc. are appropriately made.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "part" and "%" are based on weight.

The following were used as raw materials.
1. Polycarbonate resin (A):
Polycarbonate resin caliber 200-80 synthesized from bisphenol A and carbonyl chloride
(Product name, manufactured by Sumika Styron Polycarbonate Co., Ltd., "Calibur" is a registered trademark of Styron Europe GmbH, viscosity average molecular weight: 15,000, hereinafter referred to as "PC")

2. Melt viscosity modifier (B) (polyether derivative of the following formula):
2-1. Modified glycol (polyether derivative) consisting of a tetramethylene glycol unit and a 2-methyltetramethylene glycol unit:
_{HO- (CH 2 CH 2 CH 2} CH 2 O) 22 (CH 2 CH 2 CH (CH 3) CH 2 O) 5 -H
PTG-L2000
(Product name, Hodogaya Chemical Co., Ltd., weight average molecular weight: 2000, hereinafter referred to as "compound B1")

2-2. Modified glycol (polyether derivative) consisting of a tetramethylene glycol unit and a 1-ethylethylene glycol unit:
_{HO- (CH 2 CH 2 CH 2} CH 2 O) 24 (CH 2 CH (C 2 H 5) O) 13 -H
DCD-2000
(Product name, NOF Corporation, weight average molecular weight: 2000, hereinafter referred to as "compound B2")

2-3. Modified glycol (polyether derivative) consisting of ethylene glycol unit and propylene glycol unit:
_{C 4 H 9 O- (CH 2} CH 2 O) 30 (CH 2 CH (CH 3) O) 30 -H
UniLube 50MB-72
(Product name, NOF Corporation, weight average molecular weight: 3000, hereinafter referred to as "compound B3")

2-4. Modified glycol (polyether derivative) consisting of ethylene glycol unit and propylene glycol unit:
_{C 4 H 9 O- (CH 2} CH 2 O) 21 (CH 2 CH (CH 3) O) 14 -H
UniLube 60MB-26I
(Product name, NOF Corporation, weight average molecular weight: 1700, hereinafter referred to as "compound B4")

2-5. Modified glycol (polyether derivative) consisting of ethylene glycol unit and propylene glycol unit:
_{HO- (CH 2 CH 2 O)} 17 (CH 2 CH (CH 3) O) 17 -H
Unilube 50 DE-25
(Trade name, NOF (manufactured by KK, weight average molecular weight: 1750, hereinafter referred to as “compound B5”))

3. Phosphite compound (C):
3-1. Tris(2,4-di-t-butylphenyl)phosphite represented by the following formula

イルガフォス１６８
（商品名、ＢＡＳＦ社製、以下「化合物Ｃ１」という）
３−２．以下の式で表される、２，４，８，１０−テトラ−ｔ−ブチル−６−〔３−（３−メチル−４−ヒドロキシ−５−ｔ−ブチルフェニル）プロポキシ〕ジベンゾ〔ｄ，ｆ〕〔１，３，２〕ジオキサホスフェピン

Irgafoss 168
(Brand name, manufactured by BASF, hereinafter referred to as "Compound C1")
3-2. 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f represented by the following formula: ] [1,3,2]Dioxaphosphine

スミライザーＧＰ
（商品名、住友化学（株）製、以下「化合物Ｃ２」という）

Sumilizer GP
(Product name, Sumitomo Chemical Co., Ltd., hereinafter referred to as "Compound C2")

3-3. 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5] represented by the following formula Undecane

アデカスタブＰＥＰ−３６
（商品名、（株）ＡＤＥＫＡ製、以下「化合物Ｃ３」という）

ADEKA STAB PEP-36
(Product name, manufactured by ADEKA Corporation, hereinafter referred to as "Compound C3")

(Examples 1 to 17 and Comparative Examples 1 to 6)
The above raw materials were put into a tumbler at a ratio shown in Tables 1 and 2 all together, dry-mixed for 10 minutes, and then melted using a twin-screw extruder (TEX30α manufactured by Japan Steel Works, Ltd.). Melt kneading was carried out at a temperature of 220° C. to obtain pellets of a polycarbonate resin composition. The pellets obtained in Examples and Comparative Examples are substantially elliptic cylinders, and the aggregate of 100 pellets has an average length of about 5.1 mm to about 5.4 mm and an elliptical cross section. The average value of the major axis was about 4.1 mm to about 4.3 mm, and the average value of the minor axis was about 2.2 mm to about 2.3 mm.

Using the obtained pellets, each test piece for evaluation was prepared and provided for evaluation according to the following method. The results are shown in Tables 1 and 2.

(Measurement method of melt viscosity)
After drying the obtained pellets and the pellets of the polycarbonate resin (A) at 120° C. for 4 hours or more, using a capillary rheometer (manufactured by Shimadzu Corporation, Flow Tester CFT-500), a measurement temperature of 220° C. and a shear rate of 1 sec. ^The melt viscosity was measured in the range of ^{−1 to} 100 sec ⁻¹ . The melt viscosity of the polycarbonate resin composition at a shear rate of 10 sec ⁻¹ was η1, and the melt viscosity of the polycarbonate resin (A) was η2.

(Method for producing test piece)
After drying the obtained pellets at 120° C. for 4 hours or more, using an injection molding machine (ROBOSHOT S2000i100A manufactured by FANUC CORPORATION) at a molding temperature of 360° C. and a mold temperature of 80° C., JIS K 7139 “Plastic- A prescribed multipurpose test piece A type (total length 168 mm×thickness 4 mm) was prepared in “Test piece”. The end face of this test piece was cut, and the cut end face was mirror-finished using a resin plate end face mirror machine (Megaro Technica Co., Ltd., Plastic Beauty PB-500).

(Evaluation method of integrated transmittance)
A long light path measurement attachment device is installed in a spectrophotometer (UH4150, manufactured by Hitachi, Ltd.), and a 50 W halogen lamp is used as a light source. A mask before light source is 5.6 mm×2.8 mm, a mask before sample is 6.0 mm× Using 2.8 mm, the spectral transmittance of each 1 nm test piece was measured in the wavelength range of 380 to 780 nm in the entire length direction of the test piece. The measured spectral transmittances were integrated and the tens digit was rounded off to obtain each integrated transmittance. An integrated transmittance of 30,000 or more was evaluated as good (indicated by ◯ in the table), and a value of less than 30,000 was evaluated as poor (indicated by x in the table).

(Yellowness evaluation method)
Based on the spectral transmittance measured in the integrated transmittance evaluation method, the standard light source D65 was used to determine the yellowness of each of the 10-degree visual fields. It should be noted that a yellowness of 20 or less was evaluated as good (indicated by ◯ in the table), and a value of more than 20 was evaluated as poor (indicated by x in the table).

In the polycarbonate resin compositions of Examples 1 to 18, the polycarbonate resin (A) contains a melt viscosity modifier (B) such as a specific polyether derivative and a phosphite compound (C). It is blended in proportion. Therefore, the test piece molded from the polycarbonate resin composition has high integrated transmittance and low yellowness.

As described above, the polycarbonate resin compositions of Examples 1 to 18 have high light transmittance in the visible region without impairing the heat resistance originally possessed by the polycarbonate resin (A), and when molded at high temperature. However, it has excellent light transmittance. A molded product obtained by molding such a polycarbonate resin composition has a small degree of yellowness and an excellent hue, and also has an excellent hue even when molded at a high temperature.

On the other hand, in the polycarbonate resin composition of Comparative Example 1, since the amount of the melt viscosity modifier (compound B1) such as a specific polyether derivative is small, the integrated transmittance is low and the yellowness is high. Thus, the molded product obtained by molding the polycarbonate resin composition of Comparative Example 1 is inferior in brightness and hue.

The polycarbonate resin composition of Comparative Example 2 has a large amount of the specific melt viscosity modifier (compound B1), and therefore has a low cumulative transmittance and a high yellowness. Thus, the molded product obtained by molding the polycarbonate resin composition of Comparative Example 2 is inferior in brightness and hue.

The polycarbonate resin composition of Comparative Example 3 has a small amount of the phosphite compound (C), so that the test piece has a large degree of yellowness. Thus, the molded product obtained by molding the polycarbonate resin composition of Comparative Example 3 is inferior in hue.

The polycarbonate resin composition of Comparative Example 4 has a large amount of the phosphite compound (C), and thus has a low cumulative transmittance and a large yellowness. Thus, the molded product obtained by molding the polycarbonate resin composition of Comparative Example 4 is inferior in brightness and hue.

The polycarbonate resin composition of Comparative Example 5 has a small amount of the specific melt viscosity modifier (Compound B5), and thus has a low cumulative transmittance and a high yellowness. Thus, the molded product obtained by molding the polycarbonate resin composition of Comparative Example 5 is inferior in brightness and hue.

The polycarbonate resin composition of Comparative Example 6 had a large amount of the specific melt viscosity modifier (Compound B5), and thus had a low cumulative transmittance and a large yellowness. Thus, the molded product obtained by molding the polycarbonate resin composition of Comparative Example 5 is inferior in brightness and hue.

As described above, the embodiment has been described as an example of the technique of the present invention. To that end, we have provided a detailed description.

Therefore, among the constituent elements described in the detailed description, not only constituent elements that are essential for solving the problem but also constituent elements that are not essential for solving the problem are included in order to exemplify the above technology. obtain. As such, the inclusion of these non-essential components in the detailed description should not immediately be construed as essential to those non-essential components.

Further, since the above-described embodiment is for exemplifying the technique of the present invention, various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or the scope equivalent thereto.

The polycarbonate resin composition of the present invention does not impair the properties such as heat resistance and mechanical strength originally possessed by the polycarbonate resin, is excellent in thermal stability and weather resistance, and has a light transmittance even when molded at high temperature. It is an excellent one. Therefore, even for a thin light guide plate having a thickness of, for example, about 0.3 mm, there is little possibility that the hue will change and the appearance will be deteriorated, and the resin itself will not be deteriorated after high temperature molding. high.

Claims (8)

To 100 parts by weight of the polycarbonate resin (A), 0.005 to 3.0 parts by weight of the melt viscosity modifier (B) and 0.005 to 1.0 parts by weight of the phosphite compound (C) are added. A polycarbonate resin composition comprising:
When the melt viscosity at a measurement temperature of 220° C. and a shear rate of 10 sec ⁻¹ is η, the ratio η1/η2 of the melt viscosity η1 of the polycarbonate resin composition and the melt viscosity η2 of the polycarbonate resin (A) is 0.45≦η1/ satisfies η2≦0.95,
The melt viscosity modifier (B) is, it polyether derivative der represented by the following general formula _{(1), HO- (CH 2} CH 2 CH 2 CH 2 O) m (CH 2 CH 2 CH (CH _{3) CH 2 O) n-} H ( wherein, m and n are each independently an integer of 3 to 60, m + n is a compound represented by the indicating.) an integer of 8 to 90, _{HO- (CH 2 CH 2 CH 2} CH 2 O) m- (CH (CH 3) CH 2 O) nH (m / n molar ratio: 45.7 / 54.3) the number average molecular weight which is expressed by 1000 Ri polyether derivatives der neither the compound is, weight average molecular weight of the polyether derivative is 1000 to 4000, polycarbonate resin composition.
General formula (1):
RO-(X-O)m(Y-O)n-R' (1)
(In the formula, R and R′ each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X is an alkylene group having 4 carbon atoms, and Y is a branched alkylene group having 3 to 5 carbon atoms. In the group, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.) The polycarbonate resin composition according to claim 1, wherein the melt viscosity modifier (B) represented by the general formula (1) is a polyether derivative represented by the following general formula.
General formula:
_{HO- (CH 2 CH 2 CH 2} CH 2 O) m (CH 2 CH (C 2 H 5) O) n-H
(In the formula, m and n each independently represent an integer of 3 to 60, and m+n represents an integer of 8 to 90.) The phosphite compound (C) is one or more kinds of compounds selected from compounds represented by the following general formulas (5), (6) and (7). Polycarbonate resin composition.
General formula (5):

(In the formula, R ¹ represents an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group, and a represents an integer of 0 to 3.)
General formula (6):

^{(Wherein, R 2, R 3, R} 5 and ^{R 6} are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, cycloalkyl group having 5 to 8 carbon atoms, 6 to 12 carbon atoms An alkylcycloalkyl group, an aralkyl group having 7 to 12 carbon atoms or a phenyl group is shown, R ⁴ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, X is a single bond, a sulfur atom or a formula: —CHR. ^7- (Here, R< ⁷ > shows a hydrogen atom, a C1-C8 alkyl group, or a C5-C8 cycloalkyl group.) A is C1-C8. Or an alkylene group of the formula: *-COR ⁸ — (wherein R ⁸ represents a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond on the oxygen side). One of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other is a hydrogen atom or a C 1 to 8 carbon atom. Indicates an alkyl group.)
General formula (7):

(In the formula, R ⁹ and R ¹⁰ represent an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group, and b and c represent an integer of 0 to 3. ) The polycarbonate resin composition according to claim 3, wherein the compound represented by the general formula (5) is tris(2,4-di-t-butylphenyl)phosphite. The compound represented by the general formula (6) is 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]. The polycarbonate resin composition according to claim 3, which is dibenzo[d,f][1,3,2]dioxaphosphepine. The compound represented by the general formula (7) is 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro. The polycarbonate resin composition according to claim 3, which is [5,5] undecane. An optical molded article comprising the polycarbonate resin composition according to claim 1. The optical molded article according to claim 7, wherein the molded article is a light guide plate.