JP6416444B2 - Polycarbonate resin composition for optical parts and molded product comprising the same - Google Patents

Description

  The present invention relates to a polycarbonate resin composition for optical parts having good hue and brightness and excellent hydrolysis resistance without impairing the original characteristics of the polycarbonate resin, that is, heat resistance, mechanical strength, and the like, and a molded article comprising the same.

  For example, as disclosed in Patent Document 1, a planar light source device incorporated in a liquid crystal display device includes a light guide plate that is an optical component.

  Conventionally, polymethyl methacrylate (hereinafter referred to as PMMA) has been used as a material for the light guide plate. However, replacement of PMMA with polycarbonate resin has been promoted because it has high heat resistance and high mechanical strength. Yes.

  A polycarbonate resin is superior in mechanical properties, thermal properties, and electrical properties to PMMA, but slightly inferior in light transmittance. Therefore, the planar light source device using the light guide plate made of polycarbonate resin has a problem that the luminance is lower than that using the light guide plate made of PMMA.

  Therefore, as disclosed in, for example, Patent Documents 2 to 6, a resin composition in which a polycarbonate resin and another material are used together in order to obtain a light transmittance equal to or higher than that of PMMA and improve the luminance of the light guide plate. Various proposals have been made.

  However, the resin compositions disclosed in Patent Documents 2 to 6 are required as a recent light guide plate material (decrease in accumulated transmittance and change in hue even when exposed for a long time under high temperature and high humidity conditions, High reliability) is not fully satisfied.

JP-A-10-055712 Japanese Patent Laid-Open No. 09-020860 JP-A-11-158364 JP 2001-215336 A JP 2004-051700 A International Publication No. 2011/088335

  The present invention does not impair the properties such as heat resistance and mechanical strength inherent to the polycarbonate resin, and has excellent light transmittance and hue even when molded at a high temperature, and also has excellent hydrolysis resistance. A polycarbonate resin composition and a molded article comprising the same are provided.

  As a result of intensive studies to solve such problems, the present inventors have excluded a polycarbonate derivative (B) and a specific phosphite compound having a spiro ring skeleton from the polycarbonate resin (A). By containing a specific amount of the phosphite compound (C) and the epoxy compound (D), a resin composition having excellent hue and brightness even in molding at high temperatures and excellent hydrolysis resistance can be obtained. As a result, the present invention was completed.

一般式（５）：
ＨＯ−（ＣＨ_２ＣＨ_２Ｏ）ｍ（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）ｎ−Ｈ
（式中、ｍ及びｎは、それぞれ独立して、３〜６０の整数を示し、ｍ＋ｎは、８〜９０の整数を示す。）
一般式（６）：

（式中、Ｒ^１は、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、ａは、０〜３の整数を示す。）
一般式（７）：

（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。） That is, the polycarbonate resin composition for optical parts according to the present invention comprises a phosphite compound (C ) excluding a polycarbonate resin (A), a polyether derivative (B), and a compound represented by the following formula (2). ) And an epoxy compound (D),
The amount of the polyether derivative (B) is 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A),
The amount of the phosphite compound (C) is 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A),
The amount of the epoxy compound (D) is 0.001 to 0.2 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A),
Polyether derivative (B) is a polyether derivative represented by the following following general formula (5), the weight average molecular weight of the polyether derivative is 1000 to 4000,
The polycarbonate resin composition for optical parts, wherein the phosphite compound (C) is a compound represented by the following general formula (6) or a compound represented by the following general formula (7) object.
Formula (2):

One general formula (5):
_{HO- (CH 2 CH 2 O)} m (CH 2 CH (CH 3) 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.)
General formula (6):

(In the formula, R ¹ represents an aryl group which may be substituted with an alkyl group or an alkyl group having 1 to 20 carbon atoms, a is an integer of 0 to 3.)
General formula (7):

(In the formula, 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 an alkyl group having 6 to 12 carbon atoms. An alkylcycloalkyl group, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group, R ⁴ represents 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- (wherein R ⁷ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms), and A represents a group having 1 to 8 carbon atoms. 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). Y and Z are either a hydroxyl group or an alcohol having 1 to 8 carbon atoms. A xoxy group or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.)

  The polycarbonate resin composition for optical components in the present invention is not impaired in the heat resistance, mechanical strength and other properties inherent to the polycarbonate resin, and is excellent in light transmittance and hue even when molded at a high temperature. The molded product obtained is also excellent in hydrolysis resistance. Therefore, even with a thin light guide plate with a thickness of about 0.3 mm, for example, the appearance changes due to the hue change, and the resin itself is less likely to deteriorate through high temperature molding. Even when exposed for a long period of time, it is possible to obtain a product having a long-term reliability with a reduced integrated transmittance, a small hue change, and extremely high industrial utility value.

  Hereinafter, embodiments will be described in detail. However, more detailed explanation than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  In addition, the inventors provide the following explanation 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.

  The polycarbonate resin composition for optical components according to the present invention comprises a polycarbonate resin (A), a specific polyether derivative (B), and a phosphite compound (C) other than a specific phosphite compound. And an epoxy compound (D).

<Polycarbonate resin (A)>
The polycarbonate resin (A) is a polymer obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 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 Bis (hydroxyaryl) alkanes such as (4-hydroxy-3,5-dichlorophenyl) propane; 1,1- Bis (hydroxyaryl) cycloalkanes such as bis (4-hydroxyphenyl) cyclopentane and 1,1-bis (4-hydroxyphenyl) cyclohexane; 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3, Dihydroxy diaryl ethers such as 3'-dimethyldiphenyl ether; dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide; 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl Dihydroxy diaryl sulfoxides such as sulfoxide; dihydroxy diaryl sulfones such as 4,4′-dihydroxydiphenyl sulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone; Are 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.

  Furthermore, you may mix and use a dihydroxy diaryl compound and the trivalent or more phenol compound shown below, for example.

  Examples of the trivalent or higher valent 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-bis -[4,4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  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.

<Polyether derivative (B)>
The polyether derivative (B) used in the present invention may be, for example, a homoether polymer having 3 or more carbon atoms derived from polyoxyalkylene glycol or a copolymer (either a block or random copolymer). For example, a copolymer represented by the following general formula (1) is preferably used.
General formula (1):
RO- (X-O) m (YO) 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 represents an alkylene group having 2 to 4 carbon atoms, and Y represents an alkyl group having 3 to 5 carbon atoms. In the branched alkylene group, m and n each independently represents an integer of 3 to 60, and m + n represents an integer of 8 to 90.)

As the polyether derivative, among the polyether derivatives represented by the general formula (1), the polyether derivatives represented by the following general formula (3), general formula (4) or general formula (5) are preferable. It is.
General formula (3):
_{HO- (CH 2 CH 2 CH 2} CH 2 O) m (CH 2 CH (CH 3) 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.)

  Examples of the polyether derivative represented by the general formula (3) include polyserine DCB-2000 (weight average molecular weight 2000) and polyserine DCB-1000 (weight average molecular weight 1000) manufactured by NOF Corporation ("polyserine"). Are registered trademarks). The weight average molecular weight of the polyether derivative represented by the general formula (3) is preferably 1000 to 4000.

General formula (4):
_{C 4 H 9 O- (CH 2} CH 2) m (CH 2 CH (CH 3) 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.)

Examples of the polyether derivative represented by the general formula (4) include a modified glycol comprising 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, NOF Co., Ltd. Unilube 60MB-26I (weight average molecular weight 1700), Unilube 50MB-72 (weight average molecular weight 3000), etc. are commercially available. The weight average molecular weight of the polyether derivative represented by the general formula (4) is preferably 1000 to 4000.

General formula (5):
_{HO- (CH 2 CH 2 O)} m (CH 2 CH (CH 3) 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.)

As the polyether derivative represented by the general formula (5), a polyalkylene glycol having a molar ratio of ethylene glycol unit to propylene glycol unit of 1: 1 and hydrogen atoms at both ends (for example, HO— (CH ₂ CH ₂ O) ₁₇ (CH ₂ CH (CH ₃ ) O) ₁₇ -H is preferable, for example, Unilube 50DE-25 (weight average molecular weight of about 1750, random polymer) manufactured by NOF Corporation is commercially available. The weight average molecular weight of the polyether derivative represented by the general formula (5) is preferably 1000 to 4000.

Examples of the polyether derivatives other than the above general formulas (3) to (5) include polyoxytetramethylene-polyoxybutylene glycol, a modified tetramethylene glycol derivative 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.) are suitable. As commercially available polyoxytetramethylene-polyoxybutylene glycol, polyserine DCD-2000 (weight average molecular weight 2000) manufactured by NOF Corporation, as a modified tetramethylene glycol derivative, Hodogaya Chemical Co., Ltd. Examples thereof include PTG-1000, PTG-2000, PTG-3000, PTG-L1000, PTG-L2000, and PTG-L3000.

  The weight average molecular weight of the polyether derivative (B) used in the present invention is preferably 1000 to 4000, more preferably 2000 to 3000. When the weight average molecular weight of the polyether derivative is less than 1000, there is a fear that sufficient effect of improving the light transmittance may not be expected. Conversely, when the weight average molecular weight exceeds 4000, the clouding rate increases and the light transmission is increased. The rate may decrease.

  The quantity of a polyether derivative (B) is 0.1-2.0 mass parts with respect to 100 mass parts of polycarbonate resin (A), and it is further preferable that it is 0.5-1.8 mass parts. When the amount of the polyether derivative is less than 0.1 parts by mass, the effect of improving light transmittance and hydrolysis resistance is insufficient. On the other hand, when the amount of the polyether derivative exceeds 2.0 parts by mass, the clouding rate increases and the light transmittance decreases.

  Until now, attempts have been made to improve the light transmittance of polycarbonate resin by adding a polyoxyalkylene glycol homopolymer having a small number of carbon atoms. However, the polyoxyalkylene glycol homopolymer has insufficient heat resistance. Therefore, when the polycarbonate resin composition containing the polyoxyalkylene glycol is molded at a high temperature, the brightness and light transmittance of the molded product are lowered. On the other hand, the specific polyether derivative (B) represented by the general formula (1) is a bifunctional random copolymer, has high heat resistance, and is represented by the general formula (1). A molded article obtained by molding a polycarbonate resin composition containing the specific polyether derivative (B) at a high temperature has high luminance and light transmittance.

  Moreover, since the polyether derivative (B) represented by the general formula (1) has an appropriate lipophilicity, it is excellent in compatibility with the polycarbonate resin (A). The transparency of the molded product obtained from the blended polycarbonate resin composition is also improved.

  Furthermore, by blending the polyether derivative (B) represented by the general formula (1), when molding the polycarbonate resin composition, it is possible to suppress generation of shear heat more than necessary, Since release properties can also be imparted to the polycarbonate resin composition, for example, a release agent such as a polyether ganosiloxane compound may not be added separately.

<Phosphorous ester compound (C)>
The polycarbonate resin composition in the present invention includes bis (2,4-di-tert-butyl) represented by the following formula (2) together with the specific polyether derivative (B) represented by the general formula (1). A phosphite compound (C) excluding -4-methylphenyl) pentaerythritol diphosphite is blended. The heat resistance inherent in the polycarbonate resin (A) is obtained by simultaneously blending the specific polyether derivative (B) described above and the phosphite compound (C) other than the compound represented by the following formula (2). Thus, a polycarbonate resin composition for an optical component having improved light transmittance, hue, and hydrolysis resistance is obtained without impairing properties such as property and mechanical strength.
Formula (2):

  As a result of intensive studies, the present inventors have found that, among phosphite compounds, when bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is used, high temperature molding is performed. In view of this point, it has been found that the hydrolysis resistance of the molded product is significantly reduced when the molded product obtained in this way is exposed for a long time under high temperature and high humidity conditions. Excluded from (C).

（式中、Ｒ^１は、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、ａは、０〜３の整数を示す。）As the phosphite compound (C), for example, a compound represented by the general formula (6) is suitable.
General formula (6):

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

In general formula (6), R ¹ is more preferably an alkyl group having 1 to 10 carbon atoms.

  Examples of the compound represented by the general formula (6) include triphenyl phosphite, tricresyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, and trisnonylphenyl phosphite. It is done. Among these, tris (2,4-di-t-butylphenyl) phosphite is particularly suitable. For example, Irgafos 168 manufactured by BASF ("Irgafos" is a registered trademark of BASF Societas Europea) is commercially available. Is available.

（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。）Examples of the phosphite compound (C) include compounds represented by the following general formula (7) in addition to the compounds represented by the general formula (6).
General formula (7):

(In the formula, 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 an alkyl group having 6 to 12 carbon atoms. An alkylcycloalkyl group, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group, R ⁴ represents 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- (wherein R ⁷ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms), and A represents a group having 1 to 8 carbon atoms. 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). Y and Z are either a hydroxyl group or an alcohol having 1 to 8 carbon atoms. A xoxy group or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.)

  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, and t-butyl. 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 a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. 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.

R ² , R ³ and R ⁵ are each independently preferably 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. In particular, R ² and R ⁵ are preferably each independently a t-alkyl group such as a t-butyl group, a t-pentyl group, or a t-octyl group, a cyclohexyl group, or a 1-methylcyclohexyl group. In particular, R ³ is a carbon number such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a t-butyl group, or a 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, a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, It is more preferably an alkyl group having 1 to 5 carbon atoms such as an n-butyl group, i-butyl group, sec-butyl group, t-butyl group, t-pentyl group.

In the general formula (7), ^{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, for ^example, alkyl groups exemplified in the description of R ^2, R 3, ^{R 5} and ^{R 6.} 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 General Formula (7), 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 groups and cycloalkyl groups exemplified in the description of R ² , R ³ , R ⁵ and R ⁶ , respectively. . In particular, 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. It is preferably a single bond, and more preferably a single bond.

In General Formula (7), 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 a methylene group, an ethylene group, a propylene group, a butylene group, a pentamethylene group, a hexamethylene group, an octamethylene group, and a 2,2-dimethyl-1,3-propylene group. And is preferably a propylene group. 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 indicates the R ^8, for example, alkylene groups exemplified in the description of A. 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 General Formula (7), any 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 represents a hydrogen atom or 1 to 1 carbon atoms. 8 represents an alkyl group. As a C1-C8 alkoxy group, a methoxy group, an ethoxy group, a propoxy group, t-butoxy group, a pentyloxy group etc. are mentioned, for example. Examples of the aralkyloxy group having 7 to 12 carbon atoms include benzyloxy group, α-methylbenzyloxy group, α, α-dimethylbenzyloxy group and the like. Examples of the alkyl group having 1 to 8 carbon atoms, for ^example, alkyl groups exemplified in the description of R ^2, R 3, ^{R 5} and ^{R 6.}

  Examples of the compound represented by the general formula (7) include 2,4,8,10-tetra-t-butyl-6- [3- (3-methyl-4-hydroxy-5-t-butylphenyl). Propoxy] dibenzo [d, f] [1,3,2] dioxaphosphine, 6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -2,4,8 , 10-Tetra-t-butyldibenzo [d, f] [1,3,2] dioxaphosphine, 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, 0-dimethyl -12H- dibenzo [d, g] [1,3,2] dioxaphosphocin, and the like. Among these, 2,4,8,10-tetra-t-butyl-6- [3- (3-methyl-4) is particularly used when the obtained polycarbonate resin composition is used in a field where optical properties are required. -Hydroxy-5-t-butylphenyl) propoxy] dibenzo [d, f] [1,3,2] dioxaphosphine is suitable, for example, Sumitizer GP ("Smilizer") manufactured by Sumitomo Chemical Co., Ltd. Is commercially available as a registered trademark.

（式中、Ｒ^１１〜Ｒ^１８は、それぞれ独立に、炭素数１〜３のアルキル基またはアルケニル基を示す。Ｒ^１１とＲ^１２、Ｒ^１３とＲ^１４、Ｒ^１５とＲ^１６、Ｒ^１７とＲ^１８とは、互いに結合して環を形成していても良い。Ｒ^１９〜Ｒ^２２は、それぞれ独立に、水素原子または炭素数１〜２０のアルキル基を示す。ｄ〜ｇは、それぞれ独立して、０〜５の整数である。Ｘ^１〜Ｘ^４は、それぞれ独立に、単結合または炭素原子を示す。Ｘ^１〜Ｘ^４が単結合である場合、Ｒ^１１〜Ｒ^２２のうち、当該単結合に繋がった官能基は一般式（８）から除外される）Moreover, the phosphite compound represented by the general formula (8) can also be used as the phosphite compound (C).
General formula (8):

^(Wherein, R 11 ^{to R 18} are independently a ^{.R 11} and ^{R 12, R 13} and ^{R 14, R 15} and ^{R 16, R 17} represents an alkyl group or an alkenyl group having 1 to 3 carbon atoms R ¹⁸ may be bonded to each other to form a ring, R ^{19 to} R ²² each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and d to g are each independently And X ^{1 to} X ⁴ each independently represents a single bond or a carbon atom, and when X ^{1 to} X ⁴ are a single bond, R ^{11 to} R ²² are The functional group linked to the single bond is excluded from the general formula (8))

  Specific examples of the compound represented by the general formula (8) include, for example, bis (2,4-dicumylphenyl) pentaerythritol diphosphite. This is a product name “Doverphos (registered trademark) S-9228” manufactured by Dover Chemical, a product name “Adekastab PEP-45” (bis (2,4-dicumylphenyl) pentaerythritol diphosphite) manufactured by ADEKA. As commercially available.

（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 addition to the compounds described above, in the present invention, among the phosphite compounds having a spiro ring skeleton represented by the general formula (9), bis (2 , 4-Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite can be used. This is because, when the compound is used, as described above, there is a high possibility that the hydrolysis resistance of the resin composition is lowered as a result of acting with a specific ether derivative.
General formula (9):

(Wherein R ⁹ and R ¹⁰ each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group optionally substituted with an alkyl group, and b and c each independently represents 0 Represents an integer of ~ 3)

Specific examples of the compound represented by the general formula (9) include bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, and the like. Bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite is commercially available from ADEKA under the trade name “ADK STAB PEP-24G”.

  The amount of the phosphite compound (C) used in the present invention is 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). 2 parts by mass is preferable. When the amount of the phosphite compound (C) is less than 0.01 parts by mass, the effect of improving light transmittance and hue is insufficient. Conversely, when the amount of the phosphite compound (C) exceeds 0.5 parts by mass, the effect of improving light transmittance and hue is insufficient.

  In addition, the phosphite compound (C) described above may be used alone or in combination of two or more.

<Epoxy compound (D)>
The polycarbonate resin composition according to the present invention further contains an epoxy compound (D). By using the polyether derivative (B) and the epoxy compound (D) in combination, a change in hue is further suppressed when a molded product obtained by high-temperature molding is exposed for a long time under high-temperature and high-humidity conditions. be able to.

  As the epoxy compound (D), a compound having one or more epoxy groups in one molecule is used. Specific examples of the epoxy compound (D) include phenyl glycidyl ether, allyl glycidyl ether, t-butylphenyl glycidyl ether, 3 ′, 4′-epoxycyclohexylmethyl-3,4-epoxycyclohexyl carboxylate, 3,4-epoxy. -6-methylcyclohexylmethyl-3 ', 4'-epoxy-6'-methylcyclohexylcarboxylate, 2,3-epoxycyclohexylmethyl-3', 4'-epoxycyclohexylcarboxylate, 4- (3,4-epoxy -5-methylcyclohexyl) butyl-3 ', 4'-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, 3,4-epoxy -6-methylcyclohexylmethyl-6'-methylsiloxycarboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, bis-epoxy dicyclopentadienyl ether, bis-epoxy ethylene glycol, bis-epoxy Cyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxytalate, epoxidized polybutadiene, cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate, N-butyl-2-isopropyl-3,4-epoxy 5-methylcyclohexylcarboxylate, octadecyl-3,4-epoxycyclohexylcarboxylate, 2-ethylhexyl-3 ′, 4′-epoxy Chlorocarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3 ', 4'-epoxycyclohexylcarboxylate, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1, 2-epoxycyclohexane, 3-methyl-5-t-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxylate, N-butyl-2,2-dimethyl-3 , 4-epoxycyclohexylcarboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3-tert-butyl-4,5-epoxytetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyldicarboxylate Rate, di-n-butyl-3-t-butyl-4,5-d Poxy-cis-1,2-cyclohexyl dicarboxylate, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, epoxidized soybean oil, epoxidized linseed oil and the like. These epoxy compounds may be used independently and may use 2 or more types together.

  Among the compounds described above, alicyclic epoxy compounds are more preferable, and 3 ', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate is still more preferable. 3 ', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate is commercially available as “trade name: Celoxide 2021P” manufactured by Daicel Corporation.

  The amount of the epoxy compound (D) used in the present invention is 0.001 to 0.2 parts by mass and 0.005 to 0.05 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). Preferably there is. When the amount of the epoxy compound (D) is out of this range, the hue stability of the molded article molded at high temperature is lowered.

  In the present invention, a hydrolysis test in which a test piece (total length: 168 mm × thickness: 4 mm) injection-molded from the polycarbonate resin composition of the present invention is left in a constant temperature and humidity chamber at 85 ° C. and 90% RH for 1000 hours. It is preferable that the change amount of the integrated transmittance in the wavelength range of 380 to 780 nm before and after the hydrolysis test is 2000 or less and the change amount of the yellowness before and after the test is 20 or less. When the amount of change in the integrated transmittance exceeds 2000, the desired transparency cannot be obtained. In addition, when the amount of change in yellowness (ΔYI) exceeds 20, transparency cannot be obtained.

  Furthermore, the polycarbonate resin composition used in the present invention is, for example, a heat stabilizer, an antioxidant, a colorant, a release agent, a softener, an antistatic agent, as long as the effects of the present invention are not impaired. Various additives such as impact modifiers, 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 polyether (B), the phosphite compound (C) and the epoxy compound (D), and various additives as necessary. For polymers other than polycarbonate resin (A), etc., the type and amount of each component are adjusted as appropriate, and these are mixed in a known mixer such as a tumbler or ribbon blender, or melt kneaded in an extruder. The method of doing is mentioned.

  The molded article for optical parts of the present invention is formed by molding the above polycarbonate resin composition for optical parts.

  There are no particular limitations on the method for producing the molded product for optical components, and examples thereof include a method of molding a polycarbonate resin composition by a known injection molding method, compression molding method, or the like.

  The molded article for an optical component according to the present invention is suitable as, for example, a light guide plate, a surface light emitter material, a light guide film, a vehicle light guide, a name plate, and the like.

  As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present invention is not limited to this, and can also be applied to embodiments in which changes, replacements, additions, omissions, etc. are made as appropriate.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass.

The following were used as raw materials.
1. Polycarbonate resin (A)
Polycarbonate resin synthesized from bisphenol A and carbonyl chloride Caliber 200-80
(Trade name, manufactured by Sumika Stylon Polycarbonate Co., Ltd., “Caliver” is a registered trademark of Stylon Europ GmbH, viscosity average molecular weight: 15000, hereinafter referred to as “PC”)

2. Polyether derivative (B)
2-1. Polyoxytetramethylene polyoxypropylene glycol (random type)
Polyserine DCB-2000
(Trade name, manufactured by NOF Corporation, weight average molecular weight: 2000, hereinafter referred to as “compound B1”)

2-2. Polyoxytetramethylene polyoxypropylene glycol (random type)
Polyserine DCB-1000
(Trade name, manufactured by NOF Corporation, weight average molecular weight: 1000, hereinafter referred to as “compound B2”)

2-3. Modified glycol consisting of ethylene glycol unit and propylene glycol unit:
HO— (CH ₂ CH ₂ O) ₁₇ (CH ₂ CH (CH ₃ ) O) ₁₇ —H
UNILOVE 50DE-25
(Trade name, NOF (made by Co., Ltd., weight average molecular weight: 1750, hereinafter referred to as “compound B3”)

2-3. Polytetramethylene ether glycol PTG-1000
(Trade name, manufactured by Hodogaya Chemical Empress Industry Co., Ltd., weight average molecular weight: 1000, hereinafter referred to as “Compound B4”)

イルガフォス１６８
（商品名、ＢＡＳＦ社製、以下「化合物Ｃ１」という）3. Phosphite compound (C)
3-1. Tris (2,4-di-t-butylphenyl) phosphite represented by the following formula

Irgaphos 168
(Trade name, manufactured by BASF, hereinafter referred to as “Compound C1”)

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）3-2. 2,4,8,10-tetra-tert-butyl-6- [3- (3-methyl-4-hydroxy-5-tert-butylphenyl) propoxy] dibenzo [d, f ] [1, 3, 2] Dioxaphosphepine

Smither GP
(Trade name, manufactured by Sumitomo Chemical Co., Ltd., hereinafter referred to as “Compound C2”)

Ｄｏｖｅｒｐｈｏｓ Ｓ−９２２８（商品名、Ｄｏｖｅｒ Ｃｈｅｍｉｃａｌ社製、以下「化合物Ｃ３」という）3-3. Bis (2,4-dicumylphenyl) pentaerythritol diphosphite (IUPAC name: 3,9-bis [2,4-bis (α, α-dimethylbenzyl) phenoxy] -2 represented by the following formula: , 4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane)

Doverphos S-9228 (trade name, manufactured by Dover Chemical, hereinafter referred to as “Compound C3”)

アデカスタブＰＥＰ−３６（商品名、ＡＤＥＫＡ製、以下「化合物Ｃ４」という）3-2. Bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (IUPAC name: 3,9-bis (2,6-di-tert-butyl-) represented by the following formula: 4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane)

ADK STAB PEP-36 (trade name, manufactured by ADEKA, hereinafter referred to as “Compound C4”)

4). Epoxy compound (D)
3 ′, 4′-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate Celoxide 2021P
(Product name, manufactured by Daicel Corporation)

  The raw materials shown in Table 1 are collectively put into a tumbler at the ratio shown in Table 1, and after dry mixing for 10 minutes, using a twin screw extruder (manufactured by Nippon Steel Works, TEX30α), a melting temperature of 220 The mixture was melt-kneaded at 0 ° C. to obtain pellets of a polycarbonate resin composition.

  Using the obtained pellet, according to the following method, each test specimen for evaluation was produced and used for evaluation.

(Test piece preparation method)
The obtained pellets were dried at 120 ° C. for 4 hours or more, and then, using an injection molding machine (manufactured by FANUC, ROBOSHOT S2000i100A) at a molding temperature of 360 ° C. and a mold temperature of 80 ° C., JIS K 7139 “Plastics— The multipurpose test piece A type (full length 168 mm × thickness 4 mm) defined in “Test piece” was produced. The end face of the test piece was cut, and the cut end face was mirror-finished using a resin plate end face mirror machine (Megaro Technica Co., Ltd., Plasticity PB-500).

(Evaluation method of integrated transmittance)
A spectrophotometer (manufactured by Hitachi, Ltd., UH4150) is equipped with a long optical path measurement accessory device, using a 50 W halogen lamp as a light source, a mask before light source 5.6 mm × 2.8 mm, a mask before sample 6.0 mm × In the state where 2.8 mm was used, the spectral transmittance of each test piece for each 1 nm in the wavelength range of 380 to 780 nm was measured in the full length direction of the test piece. The measured spectral transmittance was integrated and rounded off to the nearest tenth to obtain the total transmittance. The integrated transmittance was 30000 or more as good (indicated by ◯ in the table) and less than 30000 was defective (indicated by x in the table).

(Yellowness evaluation method)
Based on the spectral transmittance measured in the evaluation method of the accumulated transmittance, each yellow degree (hereinafter referred to as YI) was obtained in a 10 degree visual field using the standard light source D65. When YI was 20 or less, it was judged good (indicated by ◯ in the table), and when it exceeded 20, it was judged defective (indicated by x in the table).

(Evaluation of hydrolysis resistance of molded products)
The test piece prepared above was placed in a constant temperature and humidity chamber (constant temperature and humidity chamber AG-327 manufactured by ADVANTEC), and a hydrolysis test was performed at 85 ° C. and 90% RH for 1000 hours. The integrated transmittance and yellowness (hereinafter referred to as YI) of the test pieces before and after the test were measured, and Δ integrated transmittance (difference in integrated transmittance) and ΔYI (difference in YI) were determined. ΔIntegrated transmittance and ΔYI represent the degree of change in accumulated transmittance and yellowness before and after the test. The smaller the Δintegrated transmittance and ΔYI, the lower the transmittance and discoloration, and the higher the hydrolysis resistance. Are better. As the evaluation standard of the Δ accumulated transmittance, a value having a Δ accumulated transmittance value of 2000 or less was evaluated as good (◯), and a value greater than 2000 was determined as rejected (×). As an evaluation standard for ΔYI, a value of ΔYI of 20 or less was evaluated as acceptable (◯), and a value larger than 10.0 was evaluated as defective (×).

  In Table 1, the raw material of each Example and a comparative example, a mixture ratio, and an evaluation result are shown collectively.

  In the polycarbonate resin compositions of Examples 1 to 11, the polycarbonate resin (A), the specific polyether derivative (B), the phosphite compound (C), and the epoxy compound (D) were respectively described above. It is blended at a specific ratio.

  The polycarbonate resin compositions of Examples 1 to 11 are excellent in light transmittance even when molded at a molding temperature of 360 ° C. without losing the heat resistance inherent to the polycarbonate resin (A). And the molded product which shape | molded such a polycarbonate resin composition has small yellowness, and is excellent in a hue, even when it shape-processes at high temperature.

  Since the compounds represented by the general formulas (6) to (8) described above were used as the phosphite compound (C) in the polycarbonate resin compositions of Examples 1 to 11, light transmission in the visible region was used. Rate, light transmittance when molded at a high temperature, and hue when molded at a high temperature are good. Moreover, since the polycarbonate resin compositions of Examples 1 to 10 do not contain the phosphite compound (C4) represented by the above formula (2), the light transmittance decreases even after the hydrolysis test. The change in yellowness is small and the hydrolysis resistance is excellent.

  On the other hand, the polycarbonate resin composition of Comparative Example 1 is obtained by blending a polyether derivative and an epoxy compound to the same extent as in the examples, but as a phosphite ester compound, the above formula (2) is used. Since the indicated compound (C4) was used, the integrated transmittance after the hydrolysis test was lowered, the amount of change in yellowness was large, and the hydrolysis resistance was poor.

  As described above, the embodiments have been described as examples of the technology in the present invention. To that end, a detailed explanation was provided.

  Accordingly, the components described in the detailed description include not only components essential for solving the problem but also components not essential for solving the problem in order to illustrate the above technique. obtain. Therefore, it should not be immediately recognized that these non-essential components are essential as the non-essential components are described in the detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this invention, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The polycarbonate resin composition for optical parts in the present invention does not impair the properties such as heat resistance and mechanical strength inherent to the polycarbonate resin, and is excellent in light transmittance and hue even when molded at a high temperature. It also has excellent hydrolysis resistance. Therefore, even with a thin light guide plate with a thickness of about 0.3 mm, for example, the appearance changes due to the hue change, and the resin itself is less likely to deteriorate through high temperature molding. Even when exposed for a long period of time, it is possible to obtain a product having a long-term reliability with a reduced transmittance and a small change in hue, which is extremely industrially useful.

Claims (6)

An optical system comprising a polycarbonate resin (A), a polyether derivative (B), a phosphite compound (C) excluding a compound represented by the following formula (2), and an epoxy compound (D) A polycarbonate resin composition for parts,
The amount of the polyether derivative (B) is 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A),
The amount of the phosphite compound (C) is 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A),
The amount of the epoxy compound (D) is 0.001 to 0.2 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A),
The polyether derivative (B) is a polyether derivative represented by the following following general formula (5), the weight average molecular weight of the polyether derivative is 1000 to 4000,
The polycarbonate resin for optical parts, wherein the phosphite compound (C) is a compound represented by the following general formula (6) or a compound represented by the following general formula (7) Composition.
Formula (2):

One general formula (5):
_{HO- (CH 2 CH 2 O)} m (CH 2 CH (CH 3) 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.)
General formula (6):

(In the formula, R ¹ represents an aryl group which may be substituted with an alkyl group or an alkyl group having 1 to 20 carbon atoms, a is an integer of 0 to 3.)
General formula (7):

(In the formula, 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 an alkyl group having 6 to 12 carbon atoms. An alkylcycloalkyl group, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group, R ⁴ represents 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- (wherein R ⁷ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms), and A represents a group having 1 to 8 carbon atoms. 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). Y and Z are either a hydroxyl group or an alcohol having 1 to 8 carbon atoms. A xoxy group or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.)   The polycarbonate resin composition for optical components according to claim 1, wherein the compound represented by the general formula (6) is tris (2,4-di-t-butylphenyl) phosphite.   The compound represented by the general formula (7) is 2,4,8,10-tetra-t-butyl-6- [3- (3-methyl-4-hydroxy-5-tert-butylphenyl) propoxy]. The polycarbonate resin composition for optical parts according to claim 1, which is dibenzo [d, f] [1,3,2] dioxaphosphine.   The polycarbonate resin composition for optical components according to claim 1, wherein the epoxy compound (D) is 3 ', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.   The molded article for optics which consists of the polycarbonate resin composition for optical components in any one of Claims 1-4.   The optical molded product according to claim 5, wherein the molded product is a light guide plate.