TWI669342B - Polycarbonate resin composition for optical component and molded article - Google Patents

Abstract

The present invention provides an optical component which is excellent in both light transmittance and hue and excellent in hydrolysis resistance even when the molding process is performed at a high temperature without impairing the heat resistance and mechanical strength originally possessed by the polycarbonate resin. A polycarbonate resin composition and a molded article composed thereof are used. The polycarbonate resin composition for an optical component of the present invention contains: a polycarbonate resin (A), a polyether derivative (B), and a bis (2,6-di-tert-butyl-4-methylphenyl group). a phosphite-based compound (C) other than pentaerythritol diphosphate, and an epoxy compound (D); wherein the polyether derivative (B) is 0.1 to 2.0 with respect to 100 parts by mass of the polycarbonate resin (A). The mass fraction, the phosphite-based compound (C) is 0.01 to 0.5 part by mass, and the epoxy compound (D) is 0.001 to 0.2 part by mass.

Description

Polycarbonate resin composition for optical parts and molded articles composed thereof

The present invention relates to a polycarbonate resin composition for an optical component which is excellent in the original properties of the polycarbonate resin, that is, heat resistance, mechanical strength, and the like, and which is excellent in hue and brightness, and excellent in hydrolysis resistance, and is formed by the polycarbonate resin composition. Product.

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 belonging to an optical component.

The material of the light guide plate is known to use polymethyl methacrylate (hereinafter referred to as "PMMA"). However, from the viewpoint of high heat resistance and high mechanical strength, there has been an evolution from polycarbonate to polycarbonate resin.

Compared with PMMA, polycarbonate resin is superior in mechanical properties, thermal properties and electrical properties, but its light transmittance is slightly inferior. Therefore, the planar light source device using the polycarbonate resin light guide plate has a problem that the brightness is low compared to the use of the PMMA light guide plate.

Here, as disclosed in Patent Documents 2 to 6, various proposals have been made for obtaining a resin composition having a light transmittance of the same level or higher as that of PMMA, a brightness of a light guide plate, and a polycarbonate resin and other materials.

However, the resin compositions disclosed in Patent Documents 2 to 6 cannot sufficiently satisfy the requirements for light guide plate materials in recent years (long-term exposure to high temperature and high humidity conditions) The situation still does not lead to a decrease in the integral penetration rate, less hue change, and high long-term reliability).

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. Hei 10-055712

Patent Document 2: Japanese Patent Laid-Open Publication No. 09-020860

Patent Document 3: Japanese Patent Laid-Open No. Hei 11-158364

Patent Document 4: Japanese Patent Laid-Open Publication No. 2001-215336

Patent Document 5: Japanese Patent Laid-Open Publication No. 2004-051700

Patent Document 6: International Publication No. 2011/083635

According to the present invention, it is possible to provide optical properties excellent in light transmittance and hue and excellent in hydrolysis resistance even when the molding process is performed at a high temperature without impairing the heat resistance and mechanical strength originally possessed by the polycarbonate resin. A polycarbonate resin composition for a part and a molded article composed of the same.

The inventors of the present invention have intensively studied to solve this problem, and as a result, have found that the polycarbonate resin (A) contains, in a specific amount, a polyether derivative (B), a specific phosphite having a spiro ring skeleton. The phosphite-based compound (C) and the epoxy compound (D) of the compound can obtain a resin composition excellent in hue and brightness and excellent in hydrolysis resistance even when subjected to molding at a high temperature, and the present invention is completed. .

In other words, the polycarbonate resin composition for an optical component of the present invention contains a polycarbonate resin (A), a polyether derivative (B) represented by the following general formula (1), and the following formula: (2) a phosphite-based compound (C) and an epoxy compound (D) excluding the compound shown; wherein the amount of the polyether derivative (B) is 100 parts by mass based on 100 parts by mass of the polycarbonate resin (A) 0.1 to 2.0 parts by mass; the amount of the phosphite compound (C) is 0.01 to 0.5 parts by mass based on 100 parts by mass of the polycarbonate resin (A); and the amount of the epoxy compound (D) is relative to the polycarbonate resin (A) 100 parts by mass, 0.001 to 0.2 parts by mass.

General formula (1): RO-(XO) _m (YO) _n -R' (1)

(wherein 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 a branch having a carbon number of 3 to 5; Alkyl; m and n each independently represent an integer from 3 to 60; m+n represents an integer from 8 to 90.)

The polycarbonate resin composition for an optical component of the present invention does not impair the heat resistance and mechanical strength originally possessed by the polycarbonate resin, and exhibits excellent light transmittance and hue even when subjected to molding at a high temperature. Moreover, the obtained molded body is also excellent in hydrolysis resistance. Therefore, for example, even a thin light guide plate having a thickness of about 0.3 mm can be obtained without a change in the hue, resulting in a decrease in appearance and formation via high temperature. However, the resin itself has less deterioration, and the product has a low integral penetration rate, a low hue change, and a long-term reliability, and the industrial use value is extremely high.

Hereinafter, the embodiment will be described in detail. However, if necessary, a detailed explanation will be omitted. For example, a detailed description of well-known matters and a case where the same configuration is repeated will be described. This is to avoid unnecessary cues in the description, so that those skilled in the art can easily understand.

In addition, the inventors of the present invention have provided the following description for the purpose of fully understanding the present invention, and are not intended to limit the subject matter described in the claims.

The polycarbonate resin composition for an optical component of the present invention contains a polycarbonate resin (A), a specific polyether derivative (B), a phosphite-based compound (C) other than a specific phosphite-based compound, and Epoxy compound (D).

<Polycarbonate Resin (A)>

The polycarbonate resin (A) is a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. And the obtained polymer. Representative examples include polycarbonate resins produced from, for example, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A).

The dihydroxydiaryl compound may be, for example, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis (4) in addition to bisphenol A. -hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxyphenyl-3-methyl) Phenyl)propane, 1,1-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-double (4-hydroxy-3,5-dibromophenyl)propane, bis(hydroxyaryl)alkane such as 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane; 1,1- Bis(hydroxyaryl)cycloalkanes such as bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane; 4,4'-dihydroxydiphenyl ether, 4 , dihydroxydiaryl ethers such as 4'-dihydroxy-3,3'-dimethyldiphenyl ether; dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide; 4,4 '-Dihydroxydiphenylarylene, 4,4'-dihydroxy-3,3'-dimethyldiphenylarthene and the like dihydroxydiaryl fluorene; 4,4'-dihydroxydiphenyl hydrazine, A dihydroxydiaryl fluorene such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl hydrazine may be used alone or in combination of two or more. In addition to these, it is also possible to mix pipettes , dipiperidinium hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl and the like.

Further, the dihydroxydiaryl compound may be used in combination with, for example, a ternary or higher phenol compound shown below.

The ternary or higher phenolic compound may, for example, be phloroglucinol, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)-heptene, 2,4,6-dimethyl -2,4,6-tris(4-hydroxyphenyl)-heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(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 from 10,000 to 100,000, more preferably from 12,000 to 30,000. Further, when the polycarbonate resin (A) is produced, a molecular weight modifier, a catalyst, or the like may be used as needed.

<polyether derivative (B)>

The polyether derivative (B) used in the present invention may be, for example, a monoether polymer having a carbon number of 3 or more derived from a polyoxyalkylene glycol or a copolymer (block or random copolymer) For example, a copolymer of the following general formula (1) is preferably used: General formula (1): RO-(XO) _m (YO) _n -R' (1)

(wherein 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 a branch having a carbon number of 3 to 5; The alkyl group; m and n each independently represent an integer of from 3 to 60; m+n represents an integer of from 8 to 90.) Further, the polyether derivative is represented by the polyether derivative represented by the general formula (1). It is preferably a polyether derivative represented by the following general formula (3), general formula (4) or general formula (5).

General formula (3): HO-(CH ₂ CH ₂ CH ₂ CH ₂ O) _m (CH ₂ CH(CH ₃ )O) _n -H

(wherein m and n each independently represent an integer from 3 to 60, and m+n represents an integer from 8 to 90.)

For the polyether derivative represented by the general formula (3), for example, POLYSERINE DCB-2000 (weight average molecular weight 2000) manufactured by Nippon Oil Co., Ltd., POLYSERINE DCB-1000 (weight average molecular weight of 1000), etc. ("POLYSERINE" system) can be used. Trademark). The weight average molecular weight of the polyether derivative represented by the general formula (3) is preferably from 1,000 to 4,000.

General formula (4): C ₄ H ₉ O-(CH ₂ CH ₂ O) _m (CH ₂ CH(CH ₃ )O) _n -H

(wherein m and n each independently represent an integer from 3 to 60, and m+n represents an integer from 8 to 90.)

The polyether derivative represented by the general formula (4) is preferably a modified diol composed of a 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, C ₄ H ₉ O-(CH ₂ CH ₂ O) ₃₀ (CH ₂ CH(CH ₃ )O) ₃₀ -H, etc.), commercially available, for example: Nippon Oil Co., Ltd. UNILUB 60MB-26I (weight average molecular weight 1700), UNULUB 50MB-72 (weight average molecular weight 3000), and the like. The weight average molecular weight of the polyether derivative represented by the general formula (4) is preferably from 1,000 to 4,000.

General formula (5): HO-(CH ₂ CH ₂ O) _m (CH ₂ CH(CH ₃ )O) _n -H

(wherein m and n each independently represent an integer from 3 to 60, and m+n represents an integer from 8 to 90.)

The polyether derivative represented by the general formula (5) is commercially available as a polyalkylene glycol having a molar ratio of ethylene glycol unit to propylene glycol unit of 1:1 and having a hydrogen atom at both terminals (preferably, for example, HO). -(CH ₂ CH ₂ O) ₁₇ (CH ₂ CH(CH ₃ )O) ₁₇ -H, for example, UNILUB 50DE-25 (weight average molecular weight: about 1750, random polymer) manufactured by Nippon Oil Co., Ltd., etc. The weight average molecular weight of the polyether derivative represented by the formula (5) is preferably from 1,000 to 4,000.

The polyether derivative other than the above general formulas (3) to (5) is preferably, for example, polyoxytetramethylene-polyoxybutylene glycol, composed of a butylene glycol unit and a 2-methylbutylene glycol unit. The modified butanediol derivative (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.) or the like. Commercially available polyoxytetramethylene-polyoxybutylene glycol is, for example, POLYSERINE DCD-2000 (weight average molecular weight 2000) manufactured by Nippon Oil Co., Ltd., and modified butanediol derivative system. For example, PTG-1000, PTG-2000, PTG-3000, PTG-L1000, PTG-L2000, or PTG-L3000 manufactured by Hodogaya Chemical Industry Co., Ltd.

The weight average molecular weight of the polyether derivative (B) used in the present invention is preferably from 1,000 to 4,000, more preferably from 2,000 to 3,000. If the weight average molecular weight of the polyether derivative is less than 1,000, the effect of sufficiently improving the light transmittance may not be obtained. On the other hand, if the weight average molecular weight exceeds 4,000, the atomization rate may increase and the light transmittance may decrease. .

The amount of the polyether derivative (B) is 0.1 to 2.0 parts by mass, preferably 0.5 to 1.8 parts by mass, per 100 parts by mass of the polycarbonate resin (A). When the amount of the polyether derivative is less than 0.1 part by mass, the effect of improving the light transmittance and the hydrolysis resistance is insufficient. On the other hand, when the amount of the polyether derivative exceeds 2.0 parts by mass, the atomization rate increases and the light transmittance decreases.

Up to now, attempts have been made to add polyoxyalkylene glycol diols with a lower carbon number, in an attempt to increase the light transmittance of polycarbonate resins, but because of the heat resistance of the polyoxyalkylene glycol diols Since the polycarbonate resin composition blended with the polyoxyalkylene glycol is molded at a high temperature, the brightness and light transmittance of the molded article are lowered. On the other hand, the specific polyether derivative (B) represented by the general formula (1) is a bifunctional aromatic copolymer having high heat resistance and is derived from the specific polyether represented by the general formula (1). The polycarbonate resin composition of the object (B) has a high brightness and light transmittance in a molded article formed by high temperature.

Further, since the polyether derivative (B) represented by the general formula (1) has moderate oleophilicity and is excellent in compatibility with the polycarbonate resin (A), it is also possible to enhance the blending of the polyether. The transparency of the molded article obtained from the polycarbonate resin composition of the derivative (B).

Further, when the polycarbonate resin composition is formed by blending the polyether derivative (B) represented by the general formula (1), it is possible to suppress the formation of necessary shear heat and to polycarbonate. The resin composition imparts mold release property, and thus it is not necessary to additionally add a mold release agent such as a polyether organic siloxane compound.

<phosphite compound (C)>

The polycarbonate resin composition of the present invention is specific to the specific polyether derivative represented by the general formula (1) Biological (B), a phosphite-based compound (C) other than bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphate represented by the following formula (2) is blended together . By simultaneously blending the above specific polyether derivative (B) with a phosphite-based compound (C) other than the compound represented by the following formula (2), the original polycarbonate resin (A) can be prevented from being damaged. It has properties such as heat resistance and mechanical strength, and a polycarbonate resin composition for optical parts having improved light transmittance, hue, and hydrolysis resistance is obtained.

The inventors of the present invention have intensively studied and found that when bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphate is used in the phosphite-based compound, high-temperature molding is obtained. When the product is exposed to a high temperature and high humidity for a long period of time, the hydrolysis resistance of the molded article is remarkably lowered, and in view of this, the compound is excluded from the phosphate compound (C).

The phosphite-based compound (C) is preferably, for example, a compound represented by the general formula (6):

(wherein R ¹ represents an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted by an alkyl group; a is an integer of 0 to 3.)

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

The compound represented by the general formula (6) may, for example, be triphenyl phosphate, tricresyl phosphate, tris(2,4-di-t-butylphenyl)phosphate, tris(phenylphenyl)phosphate or the like. Among these, tris(2,4-di-t-butylphenyl)phosphate is more preferable, and IRGAFOS 168 ("IRGAFOS" is a registered trademark of BASF SOCIETAS EUROPAEA) by BASF Corporation is commercially available.

The phosphite-based compound (C) may be, for example, a compound represented by the following general formula (7) in addition to the compound represented by the general formula (6):

(wherein R ² , R ³ , R ⁵ and R ⁶ each independently represent 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; a cycloalkyl 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 represents a single bond, a sulfur atom or a formula: -CHR ⁷ - ( Here, R ⁷ is a group represented by a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms. A represents an alkylene group having 1 to 8 carbon atoms, or a formula: * -CCR ⁸ - (wherein R ⁸ represents a single bond, or an alkylene group having 1 to 8 carbon atoms; * represents a bond bond on the oxygen side). Y and Z systems indicate that one of them is 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 being a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.

The alkyl group having 1 to 8 carbon atoms may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a second butyl group, a third butyl group or a third pentane group. Base, isooctyl, trioctyl, 2-ethylhexyl 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, and 1-methyl-4-isopropylcyclohexyl group. Examples of the aralkyl group having 7 to 12 carbon atoms include a benzyl group, an α-methylbenzyl group, and an α,α-dimethylbenzyl group.

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, R ² and R ⁵ are each a third alkyl group such as a third butyl group, a third pentyl group or a third octyl group which are independent of each other; a cyclohexyl group or a 1-methylcyclohexyl group. In particular, R ^{3 is} preferably a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a second butyl group, a third butyl group, a third pentyl group or the like having 1 to 5 carbon atoms. The alkyl group is more preferably a methyl group, a tert-butyl group or a third 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, more preferably a hydrogen atom, a methyl group, an ethyl group, a n-propyl group, an isopropyl group or a n-butyl group. An alkyl group having 1 to 5 carbon atoms such as a benzyl group, an isobutyl group, a second butyl group, a third butyl group and a third pentyl group.

In the general formula (7), R ⁴ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. The alkyl group having 1 to 8 carbon atoms may, for example, be an alkyl group as exemplified in the description of R ² , R ³ , R ⁵ and R ⁶ . Particularly, R ^{4 is} preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a methyl group.

In the 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. The alkyl group having 1 to 8 carbon atoms and the cycloalkyl group having 5 to 8 carbon atoms are each exemplified by an alkyl group and a cycloalkyl group in the description of R ² , R ³ , R ⁵ and R ⁶ , respectively. Particularly, X is preferably a single bond, a methylene group, or a methylene group substituted with a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a t-butyl group or the like, and more preferably a system. single bond.

In the general formula (7), the A group represents an alkylene group having 1 to 8 carbon atoms or a group represented by the formula: *-COR ⁸ -. The alkylene group having 1 to 8 carbon atoms may, for example, be a methylene group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an exopeptide group, and a 2,2-dimethyl-1 group. 3-propyl, etc., preferably a propyl group. Further, R ⁸ in the formula: *-COR ⁸ - represents a single bond or an alkylene group having 1 to 8 carbon atoms. The alkylene group having a carbon number of 1 to 8 representing R ⁸ may, for example, be an alkyl group as exemplified in the description of A. R ^{8 is} preferably a single bond or an ethyl group. Further, the * in the formula: *-COR ⁸ - represents a bond bond on the oxygen side, and the carbonyl group is bonded to the oxygen atom of the phosphate group.

In the general formula (7), Y and Z represent one of 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 represents a hydrogen atom or a carbon number of 1 ~8 alkyl. The alkoxy group having 1 to 8 carbon atoms may, for example, be a methoxy group, an ethoxy group, a propoxy group, a third butoxy group or a pentyloxy group. The aralkyloxy group having 7 to 12 carbon atoms may, for example, be a benzyloxy group, an α-methylbenzyloxy group or an α,α-dimethylbenzyloxy group. The alkyl group having 1 to 8 carbon atoms may, for example, be an alkyl group as exemplified in the description of R ² , R ³ , R ⁵ and R ⁶ .

The compound represented by the general formula (7) is, for example, 2,4,8,10-tetrabutylbutyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl) ) propoxy]dibenzo[d,f][1,3,2]dioxaphophepine, 6-[3-(3,5-di-t-butyl-4- Hydroxyphenyl)propoxy]-2,4,8,10-tetrabutylbutyldibenzo[d,f][1,3,2]dioxaphospholene, 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)propenyloxy]-4,8- Di-tert-butyl-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphinooctane. Among these, when special In the field where optical properties are required, in the case of using the obtained polycarbonate resin composition, 2,4,8,10-tetrabutylbutyl-6-[3-(3-methyl-4-hydroxyl) is preferred. -5-Tertiary butyl)propoxy]dibenzo[d,f][1,3,2]dioxaphospholene, commercially available, for example, from Sumitomo Chemical Co., Ltd. SUMIRAIZA GP ("SUMIRAIZA" is a registered trademark).

Further, the phosphite-based compound (C) may be a phosphite-based compound represented by the general formula (8).

(wherein R ¹¹ to R ¹⁸ each independently represent an alkyl group or an alkenyl group having 1 to 3 carbon atoms; R ¹¹ and R ¹² , R ¹³ and R ¹⁴ , R ¹⁵ and R ¹⁶ , R ¹⁷ and R ^{18 are} also The groups may be bonded to each other to form a ring. R ¹⁹ to R ²² each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. d to g are each independently an integer of 0 to 5. The X ¹ to X ⁴ systems are each independently The ground represents a single bond or a carbon atom. When X ¹ ~ X ⁴ is a single bond, in R ¹¹ to R ²² , the functional group to which the single bond is attached is excluded from the general formula (8).

Specific examples of the compound of the general formula (8) can be, for example, bis(2,4-diisopropylphenylphenyl)pentaerythritol diphosphate. Commercially available, for example, Dover Chemical Co., Ltd. under the trade name "Doverphos (registered trademark) S-9228"; manufactured by ADEKA, under the trade name "ADKSTAB PEP-45" (bis(2,4-diisopropylphenyl) Phenyl) pentaerythritol diphosphate).

In addition to the above compounds, in the present invention, the phosphite compound (C) The phosphite-based compound having a spirocyclic skeleton represented by the general formula (9) may be other than bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphate. The reason is that when the compound is used, as described above, it acts on a specific ether derivative, and the possibility that the hydrolysis resistance of the resin composition is lowered is improved.

(wherein 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 by an alkyl group; and b and c each independently represent an integer of 0 to 3)

Specific examples of the compound represented by the general formula (9) include bis(2,4-di-t-butylphenyl)pentaerythritol diphosphate and phenylbisphenol A pentaerythritol diphosphate. The bis(2,4-di-t-butylphenyl)pentaerythritol diphosphate is commercially available, for example, under the trade name "ADKSTAB PEP-24G" manufactured by ADEKA Corporation.

The amount of the phosphite-based compound (C) used in the present invention is 0.01 to 0.5 parts by mass, preferably 0.02 to 0.2 parts by mass, per 100 parts by mass of the polycarbonate resin (A). When the amount of the phosphite-based compound (C) is less than 0.01 part by mass, the effect of improving the light transmittance and the hue is insufficient. On the other hand, when the amount of the phosphite-based compound (C) exceeds 0.5 part by mass, the effect of improving the light transmittance and the hue is insufficient.

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

<epoxy compound (D)>

The polycarbonate resin composition of the present invention further contains an epoxy compound (D). By using the polyether derivative (B) and the epoxy compound (D) in combination, it is possible to further suppress the color change of the molded article obtained by high-temperature molding and exposure to high temperature and high humidity for a long period of time.

As the epoxy compound (D), a compound having one or more epoxy groups in one molecule can be used. Specific examples of the epoxy compound (D) include phenyl epoxidized propyl ether, allyl epoxidized ether, tert-butyl phenyl epoxidized ether, and 3', 4'-epoxycyclohexyl 3-,4-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy-6'-methylcyclohexylcarboxylate Acid ester, 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'-methylcyclohexylcarboxylate, bisphenol A diglycidyl ether, tetrabromobisphenol A epoxidized propyl ether, bicyclobicyclobicyclo Pentadiene ether, bis(epoxyethylene glycol), bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenyl oxirane, octyl phthalate, ring Oxidized polybutadiene, cyclohexyl-2-methyl-3,4-epoxycyclohexylcarboxylate, N-butyl-2-isopropyl-3,4-epoxy-5-methyl Cyclohexyl carboxylate, octadecyl-3,4-epoxycyclohexylcarboxylate, 2-ethylhexyl -3',4'-epoxycyclohexylcarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3',4'-epoxycyclohexylcarboxylate, 3 , 4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1,2-epoxycyclohexane, 3-methyl-5-tert-butyl-1 , 2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxylate, N-butyl-2,2-dimethyl-3 , 4-epoxycyclohexyl carboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3-tert-butyl-4,5-epoxytetrahydrophthalic anhydride, 4,5-epoxy -Diethyl-1,2-cyclohexyldicarboxylate, di-n-butyl-3-tert-butyl-4,5-epoxy-cis-1,2-cyclohexyldicarboxylate, hydrazine Acid ring Oxypropyl propyl ester, diglycidyl hexahydrophthalic acid, epoxidized soybean oil, epoxidized linseed oil, and the like. These epoxy compounds may be used singly or in combination of two or more.

Among the above compounds, an alicyclic epoxy compound and a particularly preferred 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate are more preferred. 3',4'-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate is commercially available under the trade name "Celloxide 2021P" manufactured by Daicel Co., Ltd.

The amount of the epoxy compound (D) used in the present invention is 0.001 to 0.2 parts by mass, preferably 0.005 to 0.05 parts by mass, per 100 parts by mass of the polycarbonate resin (A). When the amount of the epoxy compound (D) exceeds this range, the hue stability of the high-temperature molded article is lowered.

In the present invention, a test piece (full length 168 mm × thickness 4 mm) formed by injection molding of the polycarbonate resin composition of the present invention is placed in a constant temperature and humidity chamber at 85 ° C and 90% RH for 1000 hours to carry out a hydrolysis test. The integral penetration rate in the region of 380 to 780 nm is preferably 2,000 or less before and after the hydrolysis test, and the amount of change in yellow chromaticity before and after the test is preferably 20 or less. If the amount of change in the integral penetration exceeds 2,000, the desired transparency cannot be obtained. Further, if the amount of change in yellow chromaticity (ΔYI) exceeds 20, transparency cannot be obtained.

Further, the polycarbonate resin composition used in the present invention may be appropriately blended, for example, a heat stabilizer, an antioxidant, a colorant, a mold release agent, a softener, or the like, within a range not impairing the effects of the present invention. Various additives such as an antistatic agent and an impact modifier, or a polymer other than the polycarbonate resin (A).

The method for producing the polycarbonate resin composition is not particularly limited, and the polycarbonate resin (A), the polyether (B), the phosphite compound (C), the epoxy compound (D), and, if necessary, Various additives and polymerization other than polycarbonate resin (A) The type and amount of each component are appropriately adjusted, and the method of mixing by a known mixer such as a drum or a belt blender or a method of performing melt kneading by an extruder is carried out.

The molded article for an optical component of the present invention is obtained by molding the polycarbonate resin composition for an optical component.

The method for producing the molded article for an optical component is not particularly limited, and for example, a method of molding a polycarbonate resin composition by a known injection molding method, compression molding method, or the like can be employed.

The molded article for an optical component of the present invention is suitably applied to, for example, a light guide plate, a surface light-emitting material, a light guide film, a light guide for a vehicle, a nameplate, and the like.

As described above, the embodiments of the technology disclosed in the present application are exemplified. However, the technology of the present invention is not limited thereto, and may be applied to an embodiment in which modifications, substitutions, additions, omissions, and the like are appropriately performed.

[Examples]

The invention will be specifically described below by way of examples, but the invention is not limited to the embodiments. In addition, "parts" and "%" are quality benchmarks, respectively, unless otherwise stated.

The following materials were used as the raw materials.

1. Polycarbonate resin (A)

Polycarbonate resin synthesized from bisphenol A and carbonium dichloride

CALIBER200-80

(trade name, Sumika Styron Polycarbonate Co., Ltd., "CALIBER" is a registered trademark of Styron Europe GmbH, viscosity average molecular weight: 15000, hereinafter referred to as "PC")

2. Polyether derivative (B) 2-1. Polyoxytetramethylene polyoxypropylene diol (random type)

POLYSERINE DCB-2000

(trade name, daily oil (stock) system, weight average molecular weight: 2000, hereinafter referred to as "compound B1")

2-2. Polyoxytetramethylene polyoxypropylene diol (random type)

POLYSERINE DCB-1000

(trade name, daily oil (stock) system, weight average molecular weight; 1000, hereinafter referred to as "compound B2")

2-3. Modified diol formed from ethylene glycol unit and propylene glycol unit:

HO-(CH ₂ CH ₂ O) ₁₇ (CH ₂ CH(CH ₃ )O) ₁₇ -H

UNILUB 50DE-25

(trade name, daily oil (stock) system, weight average molecular weight: 1750, hereinafter referred to as "compound B3")

2-3. Polytetramethylene ether glycol

PTG-1000

(Product name, Hodogaya Chemical Queen's Industry Co., Ltd., weight average molecular weight: 1000, hereinafter referred to as "Compound B4")

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

(product name, BASF company, hereinafter referred to as "compound C1")

3-2. 2,4,8,10-tetrabutylbutyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy] Dibenzo[d,f][1,3,2]dioxaphospholene

SUMIRAIZA GP

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

3-3. Bis(2,4-diisopropylphenylphenyl)pentaerythritol diphosphate as shown in the following formula (IUPAC designation: 3,9-bis[2,4-bis(α,α-dimethylbenzyl) Phenoxy]-2,4,8,10-four -3,9-diphosphospiro[5.5]undecane)

Doverphos S-9228 (trade name, manufactured by Dover Chemical Co., hereinafter referred to as "Compound C3")

3-2. Bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphate as shown in the following formula (IUPAC designation: 3,9-bis(2,6-di-t-butyl) -4-methylphenoxy)-2,4,8,10-four -3,9-diphosphospiro[5,5]undecane)

ADKSTAB PEP-36 (trade name, ADEKA system, hereinafter referred to as "compound C4")

4. Epoxy compound (D)

3',4'-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate

Celloxide 2021P

(trade name, Daicel (share) system)

The raw materials shown in Table 1 were placed in a drum at a time according to the ratio shown in Table 1, and after dry mixing for 10 minutes, a twin-screw extruder (manufactured by Nippon Steel Works Co., Ltd., TEX30α) was used, and melt-kneading was carried out at a melting temperature of 220 ° C. , obtained polycarbonate resin group Particles of the product.

Using the obtained pellets, each of the evaluation test pieces was prepared and evaluated according to the following method.

(Method of making test piece)

After the obtained pellets were dried at 120 ° C for 4 hours or more, an injection molding machine (manufactured by FANUC Co., Ltd., ROBOSHOT S2000i100A) was used, and a molding temperature of 360 ° C and a mold temperature of 80 ° C were used to prepare a plastic test piece according to JIS K7139. The specified multi-purpose test piece type A (full length 168 mm × thickness 4 mm). The end surface of the test piece was subjected to cutting, and the surface of the cut end surface was mirror-finished using a resin plate end face mirror machine (manufactured by Meike Technology Co., Ltd., PLA-BEAUTY PB-500).

(Method for evaluating the penetration rate of points)

A long-path measuring device is installed in a spectroscopic spectrometer (manufactured by Hitachi, Ltd., UH4150). The light source uses a 50W halogen lamp, and the mask is 5.6mm × 2.8mm before the light source is used, and the mask before the sample is 6.0mm × 2.8mm. In the state, the light transmittance of each of the test pieces measured for the entire length of the test piece was measured every 1 nm in the wavelength range of 380 to 780 nm. The spectral transmittance measured by the integral is obtained by rounding off the tens digits. In addition, the point penetration rate of 30,000 or more is rated as "good" (marked as "○" in the table), and if it is less than 30,000, it is rated as "bad" (marked as "X" in the table).

(Method for evaluating yellow color)

According to the spectral transmittance measured in the integral penetration rate evaluation method, each yellow chromaticity (hereinafter referred to as "YI") was obtained using a standard light source D65 using a 10-degree field of view. In addition, YI is rated as good under 20 (marked as "○" in the table), and if it exceeds 20, it is rated as "poor" (marked as "X" in the table).

(Evaluation of hydrolysis resistance of molded product)

The test piece prepared as described above was placed in a constant temperature and humidity chamber (Constant Temperature and Humidity Apparatus AG-327 manufactured by ADVANTEC Co., Ltd.), and subjected to a hydrolysis test for 1000 hours under conditions of 85 ° C and 90% RH. The integral penetration rate and yellow chromaticity (hereinafter referred to as "YI") of the test piece before and after the test were measured, and the Δ integral transmittance (integral transmittance difference) and ΔYI (YI difference) were obtained. "Δ integral penetration rate" and "△YI" indicate the degree of change in integral penetration rate and yellow chromaticity before and after the test. The smaller the Δ integral penetration rate and ΔYI, the lower the transmittance and the less the discoloration. The more excellent the hydrolysis resistance. The evaluation criteria of the Δ integral penetration rate were rated as "good" (○) for those having a Δ-integral transmittance value of 2,000 or less, and as "unqualified" (×) for those having a Δ integral transmittance value of more than 2,000. The evaluation criteria of ΔYI were rated as "acceptable" (○) for those having a ΔYI value of 20 or less, and as "bad" (×) for those having a value of more than 10.0.

Table 1 shows the raw materials, blending ratios, and evaluation results of the respective examples and comparative examples.

The polycarbonate resin compositions of Examples 1 to 11 are each blended with a specific polyether derivative (B), a phosphite compound (C), and a ring in the polycarbonate resin (A) in the above specific ratio. Oxygen compound (D).

The polycarbonate resin compositions of Examples 1 to 11 did not impair the heat resistance originally possessed by the polycarbonate resin (A), and were excellent in light transmittance even when the molding process was carried out at a high temperature of 360 ° C. Moreover, even if the molded article formed from such a polycarbonate resin composition is subjected to a molding process at a high temperature, the yellow chromaticity is small and the hue is excellent.

In the polycarbonate resin compositions of Examples 1 to 11, since the phosphite-based compound (C) is a compound represented by the above general formulas (6) to (8), the light transmittance in the visible region is high and the temperature is high. The light transmittance at the time of molding processing and the hue at the time of high temperature molding are good. Further, in the polycarbonate resin compositions of Examples 1 to 10, since the phosphite-based compound (C4) represented by the above formula (2) was not contained, the light transmittance was lowered and yellow color was obtained after the hydrolysis test. The degree of change is small and the hydrolysis resistance is excellent.

On the other hand, in the polycarbonate resin composition of Comparative Example 1, the polyether derivative and the epoxy compound were blended in the same manner as in the examples, but the phosphite ester compound was used as shown in the above formula (2). Since the compound (C4) has a reduced integral penetration rate after the hydrolysis test, the amount of change in yellow chromaticity is also large, and hydrolysis resistance is poor.

As described above, the technical examples of the present invention are illustrative of the embodiments. A detailed description is provided for this purpose.

Therefore, the detailed description of the constituent elements described is not only a constituent element necessary for solving the problem, but also a constituent element necessary for solving the problem by exemplifying the above technique. Therefore, these non-essential constituent elements are described in the description of the embodiments, and it should not be intuitively determined that such non-essential constituent elements are necessary. In addition, since the above-described embodiments are intended to exemplify the technology of the present invention, various changes, substitutions, additions, omissions and the like may be made within the scope of the claims.

(industrial availability)

The polycarbonate resin composition for an optical component of the present invention does not impair the properties such as heat resistance and mechanical strength originally possessed by the polycarbonate resin, and is excellent in light transmittance and hue, and hydrolysis resistance even when subjected to molding at a high temperature. Excellent also. Therefore, for example, even a thin light guide plate having a thickness of about 0.3 mm rarely causes a decrease in appearance due to a hue change, and a deterioration of the resin itself due to high-temperature molding, and a low penetration rate even after prolonged exposure to high temperature and high humidity. There are few changes in hue, and products with high long-term reliability can be obtained, and industrial use value is extremely high.

Claims (5)

A polycarbonate resin composition for an optical component, comprising: a polycarbonate resin (A), a polyether derivative (B), a phosphite compound (C), and an epoxy compound (D); The amount of the ether derivative (B) is 0.1 to 2.0 parts by mass based on 100 parts by mass of the polycarbonate resin (A); and the amount of the above phosphite compound (C) is relative to the above polycarbonate resin (A) 100 parts by mass, 0.01 to 0.5 parts by mass; the amount of the epoxy compound (D) is 0.001 to 0.2 parts by mass based on 100 parts by mass of the polycarbonate resin (A); and the above polyether derivative (B) is a polyether derivative represented by the following general formula (3), which has a weight average molecular weight of 1000 to 4000; general formula (3): HO-(CH ₂ CH ₂ CH ₂ CH ₂ O) _m (CH) ₂ CH(CH ₃ )O) _n -H wherein m and n each independently represent an integer of from 3 to 60, and m+n represents an integer of from 8 to 90; and as the phosphite compound (C), a compound other than the compound represented by the following formula (2), and a compound represented by the following general formula (6) and a compound represented by the following general formula (8); In the formula, R ¹ represents an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted by an alkyl group; a is an integer of 0 to 3; In the formula, R ¹¹ to R ¹⁸ each independently represent an alkyl group or an alkenyl group having 1 to 3 carbon atoms; R ¹¹ and R ¹² , R ¹³ and R ¹⁴ , R ¹⁵ and R ¹⁶ , and R ¹⁷ and R ¹⁸ may be used. Coupling with each other to form a ring; R ¹⁹ to R ²² each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; d to g are each independently an integer of 0 to 5; and X ¹ to X ⁴ are each independently Represents a single bond or a carbon atom; when X ¹ ~X ⁴ is a single bond, in R ¹¹ to R ²² , the functional group to which the single bond is attached is excluded from the general formula (8); the above epoxy compound ( D) is 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate. The polycarbonate resin composition for an optical component according to claim 1, wherein the compound represented by the above general formula (6) is tris(2,4-di-t-butylphenyl)phosphate. The polycarbonate resin composition for optical parts according to claim 1, wherein the compound represented by the above general formula (8) is bis(2,4-diisopropylphenylphenyl)pentaerythritol diphosphate. A molded article for optics for use in an optical component according to any one of claims 1 to 3. The polycarbonate resin composition is composed. The molded article for optics according to claim 4, wherein the molded article is a light guide plate.