JP2018141093A - Aromatic polycarbonate resin composition and molding thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aromatic polycarbonate resin composition that is suitable as a molding material of a light guide member, and is excellent in hue, moist heat resistance and thermal discoloration inhibitory effect.SOLUTION: An aromatic polycarbonate resin composition contains an aromatic polycarbonate resin (A) 100 pts.mass, blended with a phosphite stabilizer (B-I) having a spiro ring skeleton 0.001-0.1 pts.mass, a phosphite stabilizer (B-II) represented by formula (II) 0.01-0.5 pts.mass, a polybutylene glycol compound with a number average molecular weight 200-1,000 (C) 0.05-2 pts.mass, and an alicyclic epoxy compound (D) 0.0005-0.2 pts.mass. (R-Rare H, a C6-20 aryl group, or a C1-20 alkyl group).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an aromatic polycarbonate resin composition and a molded article thereof. Specifically, the present invention is an aromatic polycarbonate resin composition excellent in hue, moist heat resistance and heat discoloration suppressing effect, and a molding formed by molding this aromatic polycarbonate resin composition, which is suitable as a molding material for the light guide member. Related to goods.

  In recent years, in Europe, North America, etc., daylighting of automobiles has been promoted to improve visibility from daytime pedestrians and oncoming vehicles by installing daylights that are always lit on the headlamps and rear lamps of automobiles. . The daylight generally includes a light guide member and a light source that causes light to enter the light guide member. An incandescent lamp such as a halogen lamp is generally provided near the daylight of an automobile as a normal light source for nighttime. Therefore, the light guide member is an incandescent lamp in addition to the heat generated from the daylight light source. It is also heated by the heat generated from. Furthermore, when it rains, it is exposed to heating conditions in a high humidity environment. Heating in a high-humidity environment is a major problem even in high-temperature and high-humidity areas such as Southeast Asia. For this reason, the light guide member is required to have excellent heat resistance and moisture and heat resistance.

  Conventionally, as a constituent material of a light guide member, for example, Patent Document 1 below discloses an aromatic polycarbonate resin composition in which a phosphorus stabilizer and a fatty acid ester are blended with an aromatic polycarbonate resin. When the light guide member of the automotive lighting device is molded using the resin composition, the aromatic polycarbonate resin deteriorates due to the heat received in the molding process, and the resulting molded product may be slightly yellowish. Further, even if the light guide member does not have a yellow tint at the time of molding, the light guide member is deteriorated and yellowed by being exposed to the heat of the light source around the light guide member for a long time.

  In Patent Document 2, as an aromatic polycarbonate resin composition that improves yellowing resistance and is less susceptible to yellowing even when exposed to heating conditions for a long time, there are two types of aromatic polycarbonate resins. An aromatic polycarbonate resin composition containing a phosphite-based stabilizer and a fatty acid ester is disclosed, but no examination has been made on heat and moisture resistance.

JP 2007-204737 A JP2015-189879A

  If the heat and heat resistance of the aromatic polycarbonate resin composition is not sufficient, the molded product may become cloudy or foam in a moist heat environment, and the use cannot be continued. In addition, the molecular weight is decreased due to decomposition of the aromatic polycarbonate resin. Although the mechanical properties are also impaired, conventionally, an aromatic polycarbonate resin composition improved not only in hue and heat discoloration suppressing effect but also in moisture and heat resistance has not been provided.

  The present invention relates to an aromatic polycarbonate resin composition having a remarkably excellent hue and heat-resistant yellowing suppression effect and high heat-and-moisture resistance suitable for use in a light guide member incorporated in an automotive lighting device, and the aromatic polycarbonate resin. It is an object to provide a molded product obtained by molding the composition.

  In order to solve the above-mentioned problems, the present inventor has conducted extensive research on additives to be added to an aromatic polycarbonate resin. As a result, two specific types of phosphite stabilizers are used in combination with a relatively low molecular weight polybutylene glycol. It discovered that the said subject could be solved by mix | blending a compound and an alicyclic epoxy compound as an epoxy compound.

  The present invention has been achieved based on such findings, and the gist thereof is as follows.

[1] Phosphite stabilizer (BI) having a spiro ring skeleton as a phosphorus stabilizer (B) with respect to 100 parts by mass of the aromatic polycarbonate resin (A) and the aromatic polycarbonate resin (A) 0.001 to 0.1 parts by mass, 0.01 to 0.5 parts by mass of a phosphite stabilizer (B-II) represented by the following general formula (II), and a number average molecular weight of 200 to 1, A phosphite-based stabilizer having a spiro ring skeleton containing 0.05 to 2 parts by mass of a polybutylene glycol compound (C) less than 000 and 0.0005 to 0.2 parts by mass of an alicyclic epoxy compound (D) An aromatic polycarbonate resin composition, wherein the agent (B-1) contains bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite.

(In formula (II), R ^{21 to} R ²⁵ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)

[2] An aromatic polycarbonate resin composition according to [1], wherein the alicyclic epoxy compound (D) is 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate.

[3] In [1] or [2], the content mass ratio of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) is phosphite stabilizer (BI): The phosphite stabilizer (B-II) = 1: 1 to 30, and the total content of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) is an aromatic polycarbonate. An aromatic polycarbonate resin composition, which is 0.05 to 0.2 parts by mass with respect to 100 parts by mass of the resin (A).

[4] A molded product formed by molding the aromatic polycarbonate resin composition according to any one of [1] to [3].

[5] The molded product according to [4], which is a light guide member.

[6] The molded product according to [5], wherein the molded product is a light guide member built in an automobile lighting device.

  The aromatic polycarbonate resin composition of the present invention is a polycarbonate for a light guide member because it has good hue and good heat discoloration-inhibiting effect as well as excellent heat and heat discoloration inhibiting effect without impairing the original properties of the polycarbonate resin. It is suitable as a resin material, and can maintain high light transmission efficiency even under severe weather and high temperature and humidity. Especially, it is a light guide member built in an automobile lighting device, especially long or It can be suitably used as a thick light guide member.

It is a photograph which shows the state after PC test of the test piece of Example 1 and Comparative Examples 1 and 2.

  Hereinafter, embodiments of the present invention will be described in detail.

[Aromatic polycarbonate resin composition]
The aromatic polycarbonate resin composition of the present invention comprises an aromatic polycarbonate resin (A) and a phosphite having a spiro ring skeleton as a phosphorus stabilizer (B) with respect to 100 parts by mass of the aromatic polycarbonate resin (A). 0.001 to 0.1 parts by mass of a system stabilizer (BI) and 0.01 to 0.5 parts by mass of a phosphite stabilizer (B-II) represented by the following general formula (II); Containing 0.05 to 2 parts by mass of a polybutylene glycol compound (C) having a number average molecular weight of 200 or more and less than 1,000, and 0.0005 to 0.2 parts by mass of an alicyclic epoxy compound (D); The phosphite stabilizer (B-1) having a ring skeleton includes bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite.

(In formula (II), R ^{21 to} R ²⁵ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)

  In the present invention, the hue immediately after molding of a molded product obtained by molding the aromatic polycarbonate resin composition is referred to as “initial hue”, and yellowing when the obtained molded product is exposed to heating conditions for a long time. The effect of suppressing heat is referred to as “heat-resistant yellowing suppression effect”.

<Aromatic polycarbonate resin (A)>
The aromatic polycarbonate resin (A) is an aromatic polycarbonate polymer obtained by reacting an aromatic hydroxy compound with a diester of phosgene or carbonic acid. The aromatic polycarbonate polymer may have a branch. The method for producing the aromatic polycarbonate resin is not particularly limited, and may be a conventional method such as a phosgene method (interfacial polymerization method) or a melting method (transesterification method).

  Typical examples of the aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, and 2,2-bis (4-hydroxy-3-methylphenyl). ) Propane, 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy) -3,5-dibromophenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxybiphenyl, 3,3 ', 5 , 5′-tetramethyl-4,4′-dihydroxybiphenyl, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) Le) sulfide, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) ketone.

Among the aromatic dihydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is particularly preferable.
The aromatic dihydroxy compounds may be used alone or in combination of two or more.

  When the aromatic polycarbonate resin (A) is produced, a small amount of polyhydric phenol having 3 or more hydroxy groups in the molecule may be added in addition to the aromatic dihydroxy compound. In this case, the aromatic polycarbonate resin (A) has a branch.

  Examples of the polyhydric phenol having three or more hydroxy groups include phloroglucin, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptene-2, 4,6-dimethyl-2,4. , 6-tris (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptene-3, 1,3,5-tris (4-hydroxyphenyl) benzene, Polyhydroxy compounds such as 1,1,1-tris (4-hydroxyphenyl) ethane, or 3,3-bis (4-hydroxyaryl) oxindole (= isatin bisphenol), 5-chlorouisatin, 5,7-dichloroisatin , 5-bromoisatin and the like. Among these, 1,1,1-tris (4-hydroxylphenyl) ethane or 1,3,5-tris (4-hydroxyphenyl) benzene is preferable. The amount of the polyhydric phenol used is preferably an amount of 0.01 to 10 mol%, more preferably 0.1 to 2 mol%, based on the aromatic dihydroxy compound (100 mol%). It is.

  In the polymerization by the transesterification method, a carbonic acid diester is used as a monomer instead of phosgene. Representative examples of the carbonic acid diester include substituted diaryl carbonates typified by diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates typified by dimethyl carbonate, diethyl carbonate, di-tert-butyl carbonate and the like. These carbonic acid diesters can be used alone or in combination of two or more. Among these, diphenyl carbonate and substituted diphenyl carbonate are preferable.

  The carbonic acid diester may preferably be substituted with dicarboxylic acid or dicarboxylic acid ester in an amount of 50 mol% or less, more preferably 30 mol% or less. Representative dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate, and diphenyl isophthalate. When a part of the carbonic acid diester is substituted with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

  When an aromatic polycarbonate resin is produced by a transesterification method, a catalyst is usually used. Although there is no restriction | limiting in a catalyst seed | species, Generally basic compounds, such as an alkali metal compound, an alkaline-earth metal compound, a basic boron compound, a basic phosphorus compound, a basic ammonium compound, an amine compound, are used. Of these, alkali metal compounds and / or alkaline earth metal compounds are particularly preferred. These may be used individually by 1 type and may be used in combination of 2 or more types. In the transesterification method, the catalyst is generally deactivated with p-toluenesulfonic acid ester or the like.

  The aromatic polycarbonate resin (A) can be copolymerized with a polymer or oligomer having a siloxane structure for the purpose of imparting flame retardancy and the like.

The viscosity average molecular weight of the aromatic polycarbonate resin (A) is preferably 10,000 to 22,000. When the viscosity average molecular weight of the aromatic polycarbonate resin (A) is less than 10,000, the molded product obtained may have insufficient mechanical strength, and it may not be possible to obtain a product having sufficient mechanical strength. Moreover, when the viscosity average molecular weight of aromatic polycarbonate resin (A) exceeds 22,000, since the melt viscosity of aromatic polycarbonate resin (A) becomes large, for example, an aromatic polycarbonate resin composition is obtained by a method such as injection molding. As a result, it is not possible to obtain excellent fluidity when producing a long molded product such as a light guide member by molding, and the amount of heat generated by shearing of the resin increases, resulting in deterioration of the resin due to thermal decomposition. In some cases, a molded product having an excellent hue cannot be obtained.
The viscosity average molecular weight of the aromatic polycarbonate resin (A) is more preferably 12,000 to 18,000, and further preferably 14,000 to 17,000.

The viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and obtaining an intrinsic viscosity [η] (unit: dl / g) at a temperature of 20 ° C. using an Ubbelohde viscometer. , Η = 1.23 × 10 ⁻⁴ Mv ^0.83 . The intrinsic viscosity [η] is a value calculated from the following equation by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

  The aromatic polycarbonate resin (A) may be a mixture of two or more kinds of aromatic polycarbonate resins having different viscosity average molecular weights, or a mixture of aromatic polycarbonate resins having a viscosity average molecular weight outside the above range. It may be within the range of the viscosity average molecular weight.

<Phosphorus stabilizer (B)>
The aromatic polycarbonate resin composition of the present invention includes a phosphite stabilizer (BI) having a spiro ring skeleton (hereinafter simply referred to as “phosphite stabilizer (BI)) as the phosphorus stabilizer (B). And a phosphite stabilizer (B-II) represented by the following general formula (II) (hereinafter, simply referred to as “phosphite stabilizer (B-II)”). A).

(In formula (II), R ^{21 to} R ²⁵ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)

<Phosphite stabilizer (BI)>
The phosphite stabilizer (BI) is not particularly limited as long as it is a phosphite compound having a spiro ring skeleton, and examples thereof include those represented by the following general formula (I).

(In formula (I), R ^10A and R ^10B each independently represent an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms.)

In the general formula (I), the alkyl groups represented by R ^10A and R ^10B are preferably each independently a linear or branched alkyl group having 1 to 10 carbon atoms. When R ^10A and R ^10B are an aryl group, an aryl group represented by any of the following general formulas (Ia), (Ib), or (Ic) can be given.

(In formula (Ia), R ^A represents an alkyl group having 1 to 10 carbon atoms. In formula (Ib), R ^B represents an alkyl group having 1 to 10 carbon atoms.)

  Among these, the phosphite stabilizer (BI) used in the present invention is bis (2,6-di-tert-butyl-4-methylphenyl) penta represented by the following structural formula (IA). It is essential to include erythritol diphosphite.

  The above phosphite stabilizers (BI) may be used alone or in combination of two or more. In the phosphite stabilizer (BI), bis (2 , 6-Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferably contained in an amount of 50% by mass or more, more preferably 70% by mass or more.

<Phosphite stabilizer (B-II)>
The phosphite stabilizer (B-II) is represented by the general formula (II).

In the general formula (II), examples of the alkyl group represented by R ^{21 to} R ²⁵ include a methyl group, an ethyl group, a propyl group, an n-propyl group, an n-butyl group, a tert-butyl group, a hexyl group, and An octyl group etc. are mentioned.

  As the phosphite stabilizer (B-II), tris (2,4-di-tert-butylphenyl) phosphite represented by the following structural formula (II-A) is particularly preferable.

  The above phosphite stabilizers (B-II) may be used alone or in combination of two or more.

<Content of phosphorus stabilizer (B)>
In the aromatic polycarbonate resin composition of the present invention, the content of the phosphite stabilizer (BI) is 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). It is. When the content of the phosphite stabilizer (BI) is less than 0.001 part by mass, a sufficient heat-resistant yellowing suppression effect cannot be obtained. Even if the content of the phosphite stabilizer (BI) exceeds 0.1 parts by mass, the effect of suppressing heat yellowing tends to decrease, the gas during molding increases, and transfer defects due to mold deposits. May occur, the light transmittance of the obtained molded product may be reduced. The content of the phosphite stabilizer (BI) is preferably 0.002 parts by mass or more, more preferably 0.003 parts by mass or more, preferably 100 parts by mass of the aromatic polycarbonate resin (A). Is 0.09 parts by mass or less, more preferably 0.07 parts by mass or less, and particularly preferably 0.06 parts by mass or less.

  In the aromatic polycarbonate resin composition of the present invention, the content of the phosphite stabilizer (B-II) is 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). It is. When the content of the phosphite stabilizer (B-II) is less than 0.01 parts by mass, the initial hue and the heat yellowing suppression effect are further improved by adding the phosphite stabilizer (B-II). The improvement effect cannot be obtained sufficiently. If the content of the phosphite stabilizer (B-II) exceeds 0.5 parts by mass, the amount of gas at the time of molding increases or transfer defects due to mold deposits occur, so the light transmission of the resulting molded product There is a risk that the rate will decrease. The content of the phosphite stabilizer (B-II) is preferably 0.03 to 0.3 parts by mass, more preferably 0.05 to 0 parts per 100 parts by mass of the aromatic polycarbonate resin (A). .2 parts by mass.

  In order to more effectively obtain the effect of the combined use of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II), the phosphite system in the aromatic polycarbonate resin composition of the present invention is used. The content ratio by mass of the stabilizer (BI) and the phosphite stabilizer (B-II) is preferably such that it is 1: 1-30, more preferably 1: 1-20, still more preferably. Is in an amount such as 1: 1 to 15, particularly preferably 1: 2 to 10, particularly preferably 1: 3 to 7. The total content of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) is 0.05 to 0.2 with respect to 100 parts by mass of the aromatic polycarbonate resin (A). It is preferable that it is a mass part, and it is more preferable that it is 0.1-0.16 mass part.

<Polybutylene glycol compound (C)>
The polybutylene glycol compound (C) used in the present invention is a branched glycol compound represented by the following general formula (III).

(In Formula (III), R represents an ethyl group, X and Y each independently represent a hydrogen atom, an aliphatic acyl group having 1 to 23 carbon atoms, or an alkyl group having 1 to 23 carbon atoms, and n Represents the degree of polymerization and is an integer of 2 or more.)

  The branched polybutylene glycol compound is preferably a polybutylene glycol in which X and Y are hydrogen atoms in the general formula (III).

  As the polybutylene glycol compound (C), even if one or both ends thereof are blocked with a fatty acid or alcohol, there is no effect on the performance expression, and a fatty acid ester or etherified product can be used in the same manner. X and / or Y in the general formula (III) may be an aliphatic acyl group having 1 to 23 carbon atoms or an alkyl group.

As the fatty acid ester product, either a linear or branched fatty acid ester can be used, and the fatty acid constituting the fatty acid ester may be a saturated fatty acid or an unsaturated fatty acid. Also, those in which some hydrogen atoms are substituted with a substituent such as a hydroxyl group can be used.
The fatty acid constituting the fatty acid ester is a monovalent or divalent fatty acid having 1 to 23 carbon atoms, such as a monovalent saturated fatty acid, specifically formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid. , Enanthic acid, caprylic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid and monovalent unsaturated fatty acids, specifically, Unsaturated fatty acids such as oleic acid, elaidic acid, linoleic acid, linolenic acid and arachidonic acid, and divalent fatty acids having 10 or more carbon atoms, specifically sebacic acid, undecanedioic acid, dodecanedioic acid, tetradecanedioic acid , Tapsia and decenedioic acid, undecenedioic acid, dodecenedioic acid.
These fatty acids can be used alone or in combination. The fatty acid also includes a fatty acid having one or more hydroxyl groups in the molecule.

  Preferable specific examples of the polybutylene glycol fatty acid ester include polybutylene glycol stearate in which X and Y are aliphatic acyl groups having 18 carbon atoms in the general formula (III), and X and Y aliphatic groups having 22 carbon atoms. Examples thereof include polybutylene glycol behenate which is an acyl group.

  The alkyl group constituting the alkyl ether of polybutylene glycol may be either linear or branched, for example, carbon number such as methyl group, ethyl group, propyl group, butyl group, octyl group, lauryl group, stearyl group, etc. Examples of such a polybutylene glycol compound (C) are preferably polybutylene glycol methyl ether, ethyl ether, butyl ether, lauryl ether, stearyl ether and the like.

In the present invention, a polybutylene glycol compound (C) having a number average molecular weight of 200 or more and less than 1,000 is used. The number average molecular weight of the polybutylene glycol compound (C) is preferably 300 or more, more preferably 500 or more, preferably 900 or less, more preferably 800 or less. Exceeding the upper limit of the above range is not preferable because compatibility decreases, and if the lower limit of the above range is not reached, the amount of gas generated during molding increases, resulting in molding failure due to gas, for example, unfilled, gas burned, poor transfer May occur, which is not preferable. The number average molecular weight of a polybutylene glycol compound (C) here is the number average molecular weight computed based on the hydroxyl value measured based on JISK1577.
In addition, the lower the number average molecular weight of the polybutylene glycol compound (C), the more effective the mold contamination (mold adhesion) during molding is reduced.

  The said polybutylene glycol compound (C) may be used individually by 1 type, or may use 2 or more types together.

  In the aromatic polycarbonate resin composition of the present invention, the content of the polybutylene glycol compound (C) is 0.05 to 2 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). Even if the content of the polybutylene glycol compound (C) is less than 0.05 parts by mass or more than 2 parts by mass, the initial hue of the obtained molded product tends to be inferior. The content of the polybutylene glycol compound (C) is preferably 0.1 to 1.5 parts by mass, more preferably 0.2 to 1.2 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). More preferably, it is more than 0.5 parts by mass and 1.0 parts by mass or less.

[Alicyclic epoxy compound (D)]
As the alicyclic epoxy compound (D), an alicyclic compound having one or more epoxy groups in one molecule is used. Specifically, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate, 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, bis-epoxydicyclopentadienyl ether, bis − Epoxycyclohexyl adipate, 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-epoxycyclohexyl carboxylate, N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate, N- Butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexyl carboxylate, octadecyl-3,4-epoxycyclohexyl carboxylate, 2-ethylhexyl-3 ', 4'-epoxycyclohexyl carboxylate, 4,6-dimethyl 2,3-epoxycyclohexyl-3 ′, 4′-epoxycyclohexylcarboxylate, diethyl-4,5-epoxy-cis-1,2-cyclohexyldicarboxylate, di-n-butyl-3-t-butyl-4 , 5-epoxy-cis-1,2-cyclohexyldicarboxylate and the like can be preferably exemplified. Among these, an alicyclic epoxy compound having two or more epoxy groups in one molecule is preferable, and 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate is particularly preferable.
An alicyclic epoxy compound (D) may be used individually by 1 type, or may be used in combination of 2 or more type.

  In the aromatic polycarbonate resin composition of the present invention, the content of the alicyclic epoxy compound (D) is preferably 0.0005 to 0.2 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). Is 0.001 part by mass or more, more preferably 0.003 part by mass or more, further preferably 0.005 part by mass or more, particularly preferably 0.01 part by mass or more, particularly preferably 0.03 part by mass or more, Moreover, Preferably it is 0.15 mass part or less, More preferably, it is 0.1 mass part or less, More preferably, it is 0.07 mass part or less. When the content of the alicyclic epoxy compound (D) is less than 0.0005 parts by mass, the effect of suppressing the hue and heat discoloration is insufficient, and the effect of improving the heat and moisture resistance cannot be sufficiently obtained. When it exceeds 0.2 parts by mass, not only the heat discoloration suppressing effect is deteriorated, but also the hue and wet heat stability are lowered.

<Other ingredients>
The aromatic polycarbonate resin composition of the present invention includes, as optional components, an antioxidant, a mold release agent, an ultraviolet absorber, a fluorescent whitening agent, a dye / pigment, a flame retardant, an anti-resistance, as long as the object of the present invention is not impaired. Impact modifiers, antistatic agents, lubricants, plasticizers, compatibilizers, fillers, and the like may be blended.

<Method for producing aromatic polycarbonate resin composition>
The method for producing the aromatic polycarbonate resin composition of the present invention is not particularly limited, and for example, at any stage until the final molded product is molded, the components are mixed together or divided and melt-kneaded. A method is mentioned. As a blending method of each component, for example, a method using a tumbler, a Henschel mixer or the like, a method of quantitatively feeding to an extruder hopper with a feeder and mixing, and the like can be mentioned. Examples of the melt kneading method include a method using a single screw kneading extruder, a twin screw kneading extruder, a kneader, a Banbury mixer, and the like.

[Molding]
The molded article of the present invention is formed by molding the above-described aromatic polycarbonate resin composition of the present invention.

  Although there is no restriction | limiting in particular in the shaping | molding method of the aromatic polycarbonate resin composition of this invention, For example, an injection molding method, a compression molding method, an injection compression molding method etc. are mentioned, Preferably it is an injection molding method.

  In order to suppress thermal deterioration of the resin during molding and obtain an excellent initial hue, when molding the aromatic polycarbonate resin composition of the present invention, molding is performed in an inert gas atmosphere such as nitrogen. It is preferable to carry out.

  The molded product of the present invention formed by molding the aromatic polycarbonate resin composition of the present invention is superior to conventional products in moisture and heat resistance, and has mechanical properties due to white turbidity, foaming of the molded product, and decomposition of the aromatic polycarbonate resin. There is no problem of deterioration, and the degree of yellowing when exposed to a long time under heating conditions is low and the initial hue is remarkably good, so that the light guide member of the lighting device, particularly the light source of daylight In addition to heat generated from incandescent lamps, it can be suitably used as a light guide member for automotive lighting devices that are exposed to heating conditions or humid environments. The light transmission efficiency of the optical member can be maintained high for a long time, and the replacement frequency of the light guide member can be greatly reduced.

[YI value]
The aromatic polycarbonate resin composition of the present invention is remarkably excellent in initial hue, and can be obtained by injection molding using the aromatic polycarbonate resin composition of the present invention according to the method described in the Examples section below. The YI value of 300 mm length measured for a 300 mm long optical path molded product is usually 20 or less, preferably 16 or less, more preferably 14 or less, and exhibits a remarkably excellent hue not found in conventional products.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

  The materials used in the examples and comparative examples are as follows.

<Aromatic polycarbonate resin (A)>
Bisphenol A type aromatic polycarbonate resin produced by the interfacial polymerization method: manufactured by Mitsubishi Engineering Plastics Co., Ltd., viscosity average molecular weight 19,000

<Phosphorus stabilizer (B)>
<Phosphite stabilizer (BI)>
“ADEKA STAB PEP-36” manufactured by ADEKA: bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite represented by the structural formula (IA) (in Tables 1 and 2) , Described as “PEP-36”.)

“Doverphos” from Properties & Characteristics
S-9228 ": Bis (2,4-dicumylphenyl) pentaerythritol diphosphite represented by the following structural formula (Ia) (indicated as" S-9228 "in Table 1)

<Phosphite stabilizer (B-II)>
“ADEKA STAB AS2112” manufactured by ADEKA Corporation: Tris (2,4-di-tert-butylphenyl) phosphite represented by the structural formula (II-A) (described as “AS2112” in Tables 1 and 2).

<Polybutylene glycol compound (C)>
“Uniol PB-700” manufactured by NOF Corporation: Polybutylene glycol (number average molecular weight 700) (in Tables 1 and 2, described as “PB-700”)
“Uniol PB-500” manufactured by NOF Corporation: Polybutylene glycol (number average molecular weight 500) (in Tables 1 and 2, described as “PB-500”)

<Alicyclic epoxy compound (D)>
“Celoxide 2021P” manufactured by Daicel Corporation: 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate (described as “2021P” in Tables 1 and 2)

<Fatty acid ester>
“Rikemar S-100A” manufactured by Riken Vitamin Co., Ltd .: stearic acid monoglyceride (indicated as “S-100A” in Table 1)

[Examples 1-6 and Comparative Examples 1-3]
<Production of aromatic polycarbonate resin composition>
The components shown in Table 1 were blended so as to have the ratio shown in Table 1, and were uniformly mixed with a tumbler mixer to obtain a mixture. This mixture is supplied to a single screw extruder (“VS-40” manufactured by Isuzu Chemical Industries Ltd.) equipped with a full flight screw and a vent, and the screw rotation speed is 80 rpm, the discharge rate is 20 kg / hour, and the barrel temperature is 250 ° C. Kneaded and extruded in a strand form from the tip of the extrusion nozzle. The extrudate was quenched in a water bath and cut and pelletized using a pelletizer to obtain pellets of an aromatic polycarbonate resin composition.
The obtained aromatic polycarbonate resin composition was subjected to the following heat and humidity resistance test, and the results are shown in Table 1.

<Moisture and heat resistance test>
After drying the pellets of the aromatic polycarbonate resin composition at 120 ° C. for 4 to 8 hours with a hot-air circulating dryer, the dumbbell-shaped test was performed at a temperature of 280 ° C. with an injection molding machine (“EC100” manufactured by Toshiba Machine Co., Ltd.). A piece was molded.
This test piece was treated for 240 hours in a steam atmosphere of 110 ° C. and 85% humidity with a high accelerated life test device (pressure cooker (PC) test device) (“HATEST MODEL PC-R8D” manufactured by HIRAYAMA) The viscosity average molecular weight of the aromatic polycarbonate resin before and after the PC test was measured by the method described above. The thing with little fall of the viscosity average molecular weight after a PC test is excellent in heat-and-moisture resistance.
In addition, the photograph of the test piece of Example 1 after this PC test and the test piece of Comparative Examples 1 and 2 is shown in FIG.
As will be described later, the test piece of Example 1 had no change in appearance before and after the PC test, and both the test piece of Example 1 and the test pieces of Comparative Examples 1 and 2 were performed before the PC test. It is the same external appearance as the test piece after the PC test of Example 1.

From Table 1, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite and a specific phosphite stabilizer (B-II) are included as the phosphorus stabilizer (B). At the same time, it has been clarified that the moisture and heat resistance is improved by containing the polybutylene glycol compound (C) having a number average molecular weight of 200 or more and less than 1,000 and the alicyclic epoxy compound (D).
On the other hand, in Comparative Examples 1-3 which do not contain a polybutylene glycol compound (C) and an alicyclic epoxy compound (D), it is inferior to heat-and-moisture resistance.
FIG. 1 also shows that Example 1 has no change from that before the PC test, whereas Comparative Example 1 has white turbidity and foaming, and Comparative Example 2 has more turbidity and foaming.

  Of the above Examples 1 to 6, Examples 1, 2, 4 and Comparative Example 2 were evaluated as follows, and the results are shown in Table 2.

<Evaluation of initial hue (YI)>
After drying the pellets of the aromatic polycarbonate resin composition at 120 ° C. for 4 to 8 hours with a hot-air circulating dryer, 300 mm long optical path molding is performed at a temperature of 280 ° C. with an injection molding machine (“EC100” manufactured by Toshiba Machine Co., Ltd.). A product (6 mm × 4 mm × 300 mm, L / d = 50) was obtained. About this molded article, 300 mm length YI value was measured using the long optical path spectral transmission color meter ("ASA1" by Nippon Denshoku Industries Co., Ltd.).

<Evaluation of heat-resistant discoloration (ΔYI ₁ )>
The long optical path molded product obtained by the evaluation of the above initial hue (YI) was held at 120 ° C. for 1000 hours, and then YI was measured at 300 mm optical path length (post-treatment YI), and the difference in YI values (ΔYI ₁ = After processing, YI-initial YI) was determined, and heat discoloration (ΔYI ₁ ) was evaluated.

<Residence discoloration resistance (ΔYI ₂ ) evaluation>
A 300 mm optical path length molded product was obtained in the same manner as in the evaluation of the initial hue (YI) except that the injection molding was carried out after being retained at a temperature of 280 ° C. for 25 minutes in the injection molding machine, and the 300 mm optical path length was similarly obtained. YI was measured (YI after treatment), the difference in YI values (ΔYI ₂ = YI after residence−initial YI) was determined, and the retention discoloration resistance (ΔYI ₂ ) was evaluated.

  From Table 2, it can be seen that the aromatic polycarbonate resin composition of the present invention is excellent in the initial hue, has improved heat discoloration resistance, and has improved retention discoloration resistance. In Comparative Example 2, the initial hue and the retention discoloration resistance are good, but the heat discoloration resistance is inferior.

Claims (6)

For 100 parts by mass of the aromatic polycarbonate resin (A) and the aromatic polycarbonate resin (A),
As a phosphorus stabilizer (B), phosphite stabilizer (BI) having a spiro ring skeleton (0.001 to 0.1 parts by mass) and a phosphite stabilizer represented by the following general formula (II) (B-II) 0.01 to 0.5 parts by mass;
0.05 to 2 parts by mass of a polybutylene glycol compound (C) having a number average molecular weight of 200 or more and less than 1,000;
The phosphite stabilizer (B-1) containing 0.0005 to 0.2 parts by mass of the alicyclic epoxy compound (D) and having a spiro ring skeleton is bis (2,6-di-tert-butyl-4). -Aromatic polycarbonate resin composition comprising methylphenyl) pentaerythritol diphosphite.

(In formula (II), R ^{21 to} R ²⁵ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)   The aromatic polycarbonate resin composition according to claim 1, wherein the alicyclic epoxy compound (D) is 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate.   3. The mass ratio of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) according to claim 1 or 2, wherein the phosphite stabilizer (BI): phosphite stabilizer is contained. (B-II) = 1: 1-30, and the total content of the phosphite stabilizer (BI) and the phosphite stabilizer (B-II) is an aromatic polycarbonate resin (A) 100. An aromatic polycarbonate resin composition characterized by being 0.05 to 0.2 parts by mass with respect to parts by mass.   A molded article obtained by molding the aromatic polycarbonate resin composition according to any one of claims 1 to 3.   The molded product according to claim 4, wherein the molded product is a light guide member.   6. The molded product according to claim 5, wherein the molded product is a light guide member built in an automobile lighting device.

Images