JP7305966B2 - Polycarbonate resin composition pellets and molded articles thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to polycarbonate resin composition pellets and molded articles thereof. More specifically, the present invention relates to polycarbonate resin composition pellets excellent in hue, which are suitable as a molding material for light guide members, and molded articles obtained by molding the polycarbonate resin composition pellets.

In recent years, in Europe and North America, daytime running lights are being installed on automobile headlamps and rear lamps to improve visibility for pedestrians and oncoming vehicles during the daytime. . A daylight generally includes a light guide member and a light source that directs light into the light guide member.

Conventionally, it has been proposed to use an aromatic polycarbonate resin composition as a constituent material of a light guide member. The resulting molded article may have a slight yellow tint. However, in applications for light guide members incorporated in automotive lighting devices, for example, it is desired that the YI value of 300 mm length measured for a 300 mm long optical path molded product is small and that it has a high degree of hue. .

Patent Document 1 describes an aromatic polycarbonate resin composition having an excellent hue suitable for use as a light guide member incorporated in a lighting device for automobiles. A product containing glycol has been proposed.

JP 2016-145325 A

With the aromatic polycarbonate resin composition of Patent Document 1, it is possible to obtain a molded product with an excellent hue such that the YI value of 300 mm length measured for a 300 mm long optical path molded product is 20 or less. Further improvement in hue is desired for use as a light guide member to be incorporated in.

The present invention provides polycarbonate resin composition pellets having remarkably excellent hue, which are also suitable for use as light guide members incorporated in automotive lighting devices, and molded articles obtained by molding the polycarbonate resin composition pellets. The challenge is to

In order to solve the above problems, the present inventors have extensively studied the components in the polycarbonate resin composition pellets, and as a result, a specific aromatic alcohol and a phosphorus-based stabilizer are contained in a predetermined ratio as the component amount in the pellets. It has been found that the above problems can be solved by

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

[1] A polycarbonate resin composition pellet containing a polycarbonate resin (A), an aromatic alcohol (B) represented by the following general formula (1), and a phosphorus stabilizer (C), The content of the aromatic alcohol (B) is 0.001 to 1% by mass, and the content of the phosphorus stabilizer (C) is 0.003 to 0.5% by mass. Polycarbonate resin composition material pellets.

(In the general formula (1), X represents an alkyl group or an optionally substituted aryl group. n represents an integer of 0 to 4, and when n is 2 or more, n X is may be the same or different, k is 1 or 2.)

[2] The polycarbonate resin composition pellet according to [1], wherein the aromatic alcohol (B) represented by the general formula (1) is represented by the following general formula (1A).

(In the general formula (1A), X and n have the same definitions as in the general formula (1).)

[3] The aromatic alcohol (B) is benzyl alcohol (phenylmethanol), 4-phenylbenzyl alcohol (4-phenylphenylmethanol), 2-methylphenylmethanol, 4-methylphenylmethanol, 4-tert-butylphenyl The polycarbonate resin composition pellet according to [1] or [2], which is one or more selected from the group consisting of methanol and 1,4-benzenedimethanol.

[4] The polycarbonate resin according to any one of [1] to [3], further comprising 0.01 to 0.5% by mass of an epoxy compound (D) and/or an oxetane compound (E). composition pellets.

[5] A molded article obtained by molding the polycarbonate resin composition pellets according to any one of [1] to [4].

According to the polycarbonate resin composition pellets of the present invention, it is possible to provide a molded product with a remarkably good hue satisfying a YI value of about 16 or less at a length of 300 mm measured for a molded product with a long optical path of 300 mm.
Therefore, the light guide member obtained by using the polycarbonate resin composition pellets of the present invention can obtain high light transmission efficiency even if it is a long or thick light guide member.

Embodiments of the present invention will be described in detail below.

[Polycarbonate resin composition pellet]
The polycarbonate resin composition pellets of the present invention (hereinafter sometimes referred to as "pellets of the present invention") are composed of a polycarbonate resin (A) and an aromatic alcohol (B) represented by the following general formula (1). , a polycarbonate resin composition pellet containing a phosphorus stabilizer (C), wherein the content of the aromatic alcohol (B) in the pellet is 0.001 to 1% by mass, and the phosphorus stabilizer (C) The content of is 0.003 to 0.5% by mass, and the pellets of the present invention further contain an epoxy compound (D) and / or an oxetane compound (E) of 0.01 to You may contain 0.5 mass %.

(In the general formula (1), X represents an alkyl group or an optionally substituted aryl group. n represents an integer of 0 to 4, and when n is 2 or more, n X is may be the same or different, k is 1 or 2.)

The contents of the aromatic alcohol (B), the phosphorus stabilizer (C), the epoxy compound (D), and the oxetane compound (E) in the pellets of the present invention are determined by the method described in the Examples section below. It is a measured value.

<Polycarbonate resin (A)>
Any conventionally known polycarbonate resin can be used as the polycarbonate resin (A). The polycarbonate resin (A) includes aromatic polycarbonate resins, aliphatic polycarbonate resins, and aromatic-aliphatic polycarbonate resins, preferably aromatic polycarbonate resins.

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

Representative aromatic dihydroxy compounds include, for example, bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl ) propane, 2,2-bis(4-hydroxy-3-t-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)sulfide, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ketone etc.

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

When producing the aromatic polycarbonate resin, 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 has branches.

Examples of polyhydric phenols 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 (=isatinbisphenol), 5-chlorisatin, 5,7-dichlorisatin , 5-bromysatin and the like. Among these, 1,1,1-tris(4-hydroxyphenyl)ethane and 1,3,5-tris(4-hydroxyphenyl)benzene are preferred. The amount of the polyhydric phenol used is preferably 0.01 to 10 mol%, more preferably 0.1 to 2 mol% based on the aromatic dihydroxy compound (100 mol%). is.

Carbonic acid diesters are used as monomers instead of phosgene in the transesterification polymerization. Typical examples of carbonic acid diesters include substituted diaryl carbonates such as diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate and di-tert-butyl carbonate. These carbonic acid diesters can be used singly or in combination of two or more. Among these, diphenyl carbonate and substituted diphenyl carbonate are preferred.

The above carbonic acid diester may be substituted with a dicarboxylic acid or dicarboxylic acid ester in an amount of preferably 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 part of the carbonic acid diester is replaced with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

A catalyst is usually used when producing an aromatic polycarbonate resin by the transesterification method. Although there are no restrictions on the type of catalyst, basic compounds such as alkali metal compounds, alkaline earth metal compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds are generally used. Among them, 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.

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

The polycarbonate resin (A) preferably has a viscosity average molecular weight of 10,000 to 22,000. If the viscosity-average molecular weight of the polycarbonate resin (A) is less than 10,000, the mechanical strength of the resulting molded article may be insufficient, and a product having sufficient mechanical strength may not be obtained. When the viscosity-average molecular weight of the polycarbonate resin (A) exceeds 22,000, the melt viscosity of the polycarbonate resin (A) increases. Excellent fluidity cannot be obtained when manufacturing long molded products such as, and the amount of heat generated by shearing of the resin increases, resulting in deterioration of the resin due to thermal decomposition, resulting in excellent hue. It may not be possible to obtain a molded product.
The viscosity average molecular weight of the polycarbonate resin (A) is more preferably 12,000 to 18,000, still more preferably 14,000 to 17,000.

Here, the viscosity-average molecular weight is obtained by conversion from the solution viscosity measured at a temperature of 20° C. using methylene chloride as a solvent.

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

The pellets of the present invention are pellets of a polycarbonate resin composition, and contain the polycarbonate resin (A) as a main component, usually at least 95% by mass, preferably at least 97% by mass, more preferably at least 99% by mass. is.

<Aromatic alcohol (B)>
The aromatic alcohol (B) used in the present invention is represented by the following general formula (1), and the benzene ring is substituted with 1 to 4 alkyl groups or an optionally substituted aryl group. benzyl alcohol (phenylmethanol) or benzenedimethanol (phenylenedimethanol).

(In the general formula (1), X represents an alkyl group or an optionally substituted aryl group. n represents an integer of 0 to 4, and when n is 2 or more, n X is may be the same or different, k is 1 or 2.)
By including the aromatic alcohol (B) in the pellets of the present invention, an excellent effect of improving hue can be obtained.

In the above general formula (1), when k=2 and two hydroxymethyl groups are present, the substitution positions of the hydroxymethyl groups are preferably 1,4-positions.
It is preferable that k in the general formula (1) is 1 from the viewpoint of the effect of improving the hue. Therefore, the aromatic alcohol (B) represented by the general formula (1) is represented by the following general formula (1A). is preferably a benzyl alcohol-based compound.

(In the general formula (1A), X and n have the same definitions as in the general formula (1).)

In the general formulas (1) and (1A) above, the aryl group for X is preferably a phenyl group. The phenyl group may have an alkyl group as a substituent, and examples of the alkyl group include those described below as the alkyl group for X.
The alkyl group for X is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group of X may be a straight-chain alkyl group, a branched-chain alkyl group, or a cyclic alkyl group, but is preferably a straight-chain or branched-chain alkyl group.

n representing the number of substituents X in general formulas (1) and (1A) is 0 to 4, preferably 0 to 3, more preferably 0 to 2, particularly preferably 0 (unsubstituted) or 1 be.
In addition, when n is 2 or more, the plurality of substituents X may be the same or different.

As the substitution position of X, when the aromatic alcohol (B) has one hydroxymethyl group, the ortho position and/or para position relative to the hydroxymethyl group are preferred.

Specific examples of benzyl alcohol compounds among the aromatic alcohols (B) include benzyl alcohol (phenylmethanol), 4-methylphenylmethanol, 2-methylphenylmethanol, 3-methylphenylmethanol, 4-ethylphenylmethanol, 2 -ethylphenylmethanol, 4-isopropylphenylmethanol, 4-tert-butylphenylmethanol, 4-phenylbenzyl alcohol (4-phenylphenylmethanol), 3-phenylphenylmethanol, 2,3-dimethylphenylmethanol, 2,4- dimethylphenylmethanol, 2-methyl-3-phenylphenylmethanol, 3,5-tert-butylphenylmethanol, 2,4,6-trimethylphenylmethanol, 2,3,5,6-tetramethylphenylmethanol and the like. . Specific examples of benzenedimethanol compounds include 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,2-benzenedimethanol and the like. Among these, benzyl alcohol, 4-phenylbenzyl alcohol, 2-methylphenylmethanol, 4-methylphenylmethanol, 4-tert-butylphenylmethanol and 1,4-benzenedimethanol are preferred.

These aromatic alcohols (B) may be used singly or in combination of two or more.

The content of aromatic alcohol (B) in the pellets of the present invention is 0.001 to 1% by mass. If the content of the aromatic alcohol (B) in the pellets is excessively high, the molded article may become cloudy and the durability against heat and light may deteriorate. Therefore, the pellets of the present invention shall contain the aromatic alcohol (B) within the above range.

<Phosphorus stabilizer (C)>
The phosphorus stabilizer (C) is preferably a phosphite stabilizer (CI) having a spiro ring skeleton (hereinafter sometimes simply referred to as "phosphite stabilizer (CI)"). ), and a phosphite-based stabilizer (C-II) represented by the following general formula (II) (hereinafter sometimes simply referred to as “phosphite-based stabilizer (C-II)”), and the like. , or two or more thereof can be used, and it is particularly preferable to use the phosphite stabilizer (C-I) and the phosphite stabilizer (C-II) in combination.

(In Formula (II), R ²⁵ to R ²⁹ each independently represent a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.)

<Phosphite Stabilizer (C-I)>
The phosphite-based stabilizer (C-I) is not particularly limited as long as it is a phosphite-based compound having a spiro ring skeleton, but preferably 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 general formula (I) above, each of the alkyl groups represented by R ^10A and R ^10B is preferably a linear or branched alkyl group having 1 to 10 carbon atoms. When R ^10A and R ^10B are aryl groups, aryl groups represented by any of the following general formulas (I-1), (I-2), and (I-3) are preferred.

(In formula (I-1), R ^A represents an alkyl group having 1 to 10 carbon atoms. In formula (I-2), R ^B represents an alkyl group having 1 to 10 carbon atoms.)

Examples of the phosphite-based stabilizer (C-I) include bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite represented by the following structural formula (IA). mentioned.

As the phosphite-based stabilizer (C-I), compounds represented by the following general formula (IB) are also preferred.

(In formula (IB), R ¹¹ to R ¹⁸ each independently represent a hydrogen atom or an alkyl group, R ¹⁹ to R ²² each independently represent an alkyl group, an aryl group or an aralkyl group, a to d each independently represents an integer of 0 to 3.)

In the above general formula (IB), R ¹¹ to R ¹⁸ are each independently preferably an alkyl group having 1 to 5 carbon atoms, preferably a methyl group, and a to d are 0 is preferred.

As the compound represented by the general formula (IB), bis(2,4-dicumylphenyl)pentaerythritol diphosphite represented by the following structural formula (Ib) is preferable.

The above phosphite-based stabilizer (CI) may be used alone or in combination of two or more.

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

Examples of alkyl groups represented by R ²⁵ to R ²⁹ in general formula (II) include methyl group, ethyl group, propyl group, n-propyl group, n-butyl group, tert-butyl group, hexyl group and octyl group and the like.

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

The above phosphite-based stabilizer (C-II) may be used alone or in combination of two or more.

<Content of phosphorus stabilizer (C) in pellet>
In the pellets of the present invention, the content of the phosphorus stabilizer (C) is 0.003-0.5% by mass, preferably 0.005-0.45% by mass, more preferably 0.01-0. 4% by mass, more preferably 0.03 to 0.3% by mass. If the content of the phosphorus-based stabilizer (C) in the pellet is less than the above lower limit, the effect of improving the hue due to containing the phosphorus-based stabilizer (C) cannot be obtained. In addition, the light transmittance of the resulting molded product may decrease due to the increased amount of gas during molding and the occurrence of poor transfer due to mold deposits.

When the phosphite-based stabilizer (C-I) and the phosphite-based stabilizer (C-II) are used in combination, for the same reason, the content of the phosphite-based stabilizer (C-I) in the pellets of the present invention is preferably 0.001 to 0.5 mass%, more preferably 0.003 to 0.3 mass%, still more preferably 0.005 to 0.2 mass%, of the phosphite stabilizer (C-II) The content is preferably 0.001 to 0.5% by mass, more preferably 0.003 to 0.3% by mass, still more preferably 0.005 to 0.2% by mass, and the total of these is within the above range preferably within

In addition, in order to more effectively obtain the effects of the combined use of the phosphite stabilizer (C-I) and the phosphite stabilizer (C-II), the phosphite stabilizer ( C-I) and the phosphite-based stabilizer (C-II) are contained in a mass ratio of 1:1 to 15, particularly 1:1.5 to 10, especially 1:2 to 5. preferable.

<Epoxy Compound (D)/Oxetane Compound (E)>
The pellets of the present invention may contain an epoxy compound (D) and/or an oxetane compound (E).
By containing the epoxy compound (D) and/or the oxetane compound (E) in the pellets of the present invention, it is possible to further improve good hue and high heat discoloration resistance.

<Epoxy compound (D)>
A compound having one or more epoxy groups in one molecule is used as the epoxy compound (D). Specifically, phenyl glycidyl ether, allyl glycidyl ether, t-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl -3',4'-epoxy-6'-methylcyclohexyl carboxylate, 2,3-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate, 4-(3,4-epoxy-5-methylcyclohexyl) Butyl-3′,4′-epoxycyclohexyl carboxylate, 3,4-epoxycyclohexyl ethylene oxide, cyclohexylmethyl-3,4-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6′-methylsilo Hexyl carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene glycol , bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxytalate, epoxidized polybutadiene, 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-epoxycyclohexyl carboxylate, N-butyl-2,2-dimethyl-3,4-epoxy Cyclohexyl 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′-epoxycyclohexyl carboxylate, 4,5-epoxy tetrahydrophthalic anhydride, 3-t-butyl-4,5-epoxy tetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, di-n-butyl-3-t-butyl-4,5- Epoxy-cis-1,2-cyclohexyldicarboxylate, epoxidized soybean oil, epoxidized linseed oil and the like can be preferably exemplified. Among these, alicyclic epoxy compounds having two or more epoxy groups in one molecule are particularly preferred.
Epoxy compounds (D) may be used alone or in combination of two or more.

<Oxetane compound (E)>
As the oxetane compound, any compound having one or more oxetane groups in the molecule can be used, including monooxetane compounds having one oxetane group in the molecule and two or more oxetane groups in the molecule. Any polyoxetane compound having a functionality of two or more can be used.

Preferred examples of monooxetane compounds include compounds represented by the following general formula (III-a) or (III-b). As the polyoxetane compound, a dioxetane compound having two oxetane groups in the molecule represented by the following general formula (IV) can be preferably exemplified.

(In the formula, R ¹ represents an alkyl group, R ² represents an alkyl group or a phenyl group, R ³ represents a divalent organic group which may have an aromatic ring, and n represents 0 or 1. )

In the above general formulas (III-a), (III-b) and (IV), R ¹ is an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, preferably a methyl group or an ethyl group, Ethyl group is particularly preferred.

In general formula (III-b) above, R ² is an alkyl group or a phenyl group, preferably an alkyl group having 2 to 10 carbon atoms, a chain alkyl group, a branched alkyl group or an alicyclic alkyl group. or a chain or branched alkyl group having an ether bond (etheric oxygen atom) in the middle of the alkyl chain. Specific examples of R ² include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, 3-oxypentyl, cyclohexyl, phenyl and the like. Among them, R ² is preferably a 2-ethylhexyl group, a phenyl group, or a cyclohexyl group.

Specific examples of compounds represented by general formula (III-a) include 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3- Hydroxymethyl-3-n-butyloxetane, 3-hydroxymethyl-3-propyloxetane and the like are preferred. Among them, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane and the like are particularly preferred.
As a specific example of the compound represented by general formula (III-b), 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane and the like are particularly preferable.

In the above general formula (IV), R ³ is a divalent organic group which may have an aromatic ring, examples of which include ethylene, propylene, butylene, neopentylene and n-pentamethylene. linear or branched alkylene group having 1 to 12 carbon atoms such as n-hexamethylene group, phenylene group, formula: -CH ₂ -Ph-CH ₂ - or -CH ₂ -Ph-Ph-CH ₂ - (here, Ph represents a phenyl group) represented by a divalent group, hydrogenated bisphenol A residue, hydrogenated bisphenol F residue, hydrogenated bisphenol Z residue, cyclohexanedimethanol residue, tricyclo A decanedimethanol residue and the like can be mentioned.

Specific examples of the compound represented by the general formula (IV) include bis(3-methyl-3-oxetanylmethyl)ether, bis(3-ethyl-3-oxetanylmethyl)ether, bis(3-propyl-3- oxetanylmethyl)ether, bis(3-butyl-3-oxetanylmethyl)ether, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 3-ethyl-3{[(3-ethyloxetane -3-yl)methoxy]methyl}oxetane, 4,4′-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl] Benzene and the like are particularly preferred.

The oxetane compound (E) may be used alone or in combination of two or more.

<Content of epoxy compound (D) and/or oxetane compound (E)>
When the pellets of the present invention contain the epoxy compound (D) and / or the oxetane compound (E), the content (the total content when the epoxy compound (D) and the oxetane compound (E) are included) is preferably is 0.01 to 0.5% by mass, more preferably 0.003 to 0.3% by mass, and particularly preferably 0.005 to 0.2% by mass. When the content of the epoxy compound (D) and/or the oxetane compound (E) is less than the above lower limit, the effect of improving the hue due to the inclusion of the epoxy compound (D) and/or the oxetane compound (E) should be sufficiently obtained. When the above upper limit is exceeded, the hue tends to deteriorate and the wet heat stability tends to deteriorate.

<Other ingredients>
The pellets of the present invention may further contain antioxidants, release agents, ultraviolet absorbers, fluorescent brighteners, dyes and pigments, flame retardants, impact modifiers, and electrifiers as optional components within the range that does not impair the object of the present invention. Inhibitors, lubricants, plasticizers, compatibilizers, fillers and the like may be added.

Examples of optional components include polyalkylene glycol compounds shown below.

As the polyalkylene glycol compound, a linear alkylene ether unit (P1) represented by the following general formula (2) and a branched alkylene ether unit (P2 ) are preferred.

In general formula (2), t represents an integer of 3-6.

In general formulas (2A) to (2D), R ³¹ to R ⁴⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. At least one of R ³¹ to R ⁴⁰ in each of general formulas (2A) to (2D) is an alkyl group having 1 to 3 carbon atoms.

As the straight-chain alkylene ether unit (P1) represented by the general formula (2), when describing it as a glycol, trimethylene glycol in which t is 3, tetramethylene glycol in which t is 4, and pentamethylene in which t is 5 Glycols, hexamethylene glycol where t is 6 can be mentioned. Trimethylene glycol and tetramethylene glycol are preferred, and tetramethylene glycol is particularly preferred.

Trimethylene glycol is produced industrially by hydroformylating ethylene oxide to obtain 3-hydroxypropionaldehyde and hydrogenating it, or by hydrogenating 3-hydroxypropionaldehyde obtained by hydrating acrolein with a Ni catalyst. manufactured by the method. Trimethylene glycol is also produced by reducing glycerin, glucose, starch, etc. with microorganisms using biomethods.

As the branched alkylene ether unit represented by the general formula (2A), when this is described as glycol, (2-methyl) ethylene glycol (propylene glycol), (2-ethyl) ethylene glycol (butylene glycol), (2,2- dimethyl)ethylene glycol (neopentyl glycol) and the like.

As the branched alkylene ether unit represented by the general formula (2B), when this is described as glycol, (2-methyl) trimethylene glycol, (3-methyl) trimethylene glycol, (2-ethyl) trimethylene glycol, (3 -ethyl)triethylene glycol, (2,2-dimethyl)trimethylene glycol, (2,2-methylethyl)trimethylene glycol, (2,2-diethyl)trimethylene glycol (i.e., neopentyl glycol), (3 ,3-dimethyl)trimethylene glycol, (3,3-methylethyl)trimethylene glycol, (3,3-diethyl)trimethylene glycol and the like.

As the branched alkylene ether unit represented by the general formula (2C), when this is described as glycol, (3-methyl) tetramethylene glycol, (4-methyl) tetramethylene glycol, (3-ethyl) tetramethylene glycol, (4 -ethyl) tetramethylene glycol, (3,3-dimethyl) tetramethylene glycol, (3,3-methylethyl) tetramethylene glycol, (3,3-diethyl) tetramethylene glycol, (4,4-dimethyl) tetramethylene glycol Glycol, (4,4-methylethyl)tetramethylene glycol, (4,4-diethyl)tetramethylene glycol and the like can be mentioned, and (3-methyl)tetramethylene glycol is preferred.

As the branched alkylene ether unit represented by the general formula (2D), when this is described as glycol, (3-methyl)pentamethylene glycol, (4-methyl)pentamethylene glycol, (5-methyl)pentamethylene glycol, (3 -ethyl)pentamethylene glycol, (4-ethyl)pentamethylene glycol, (5-ethyl)pentamethylene glycol, (3,3-dimethyl)pentamethylene glycol, (3,3-methylethyl)pentamethylene glycol, (3 ,3-diethyl)pentamethylene glycol, (4,4-dimethyl)pentamethylene glycol, (4,4-methylethyl)pentamethylene glycol, (4,4-diethyl)pentamethylene glycol, (5,5-dimethyl) pentamethylene glycol, (5,5-methylethyl)pentamethylene glycol, (5,5-diethyl)pentamethylene glycol and the like.

In the above, the units represented by the general formulas (2A) to (2D) constituting the branched alkylene ether unit (P2) were described as examples of glycols for convenience, but not limited to these glycols, these alkylene oxides, Polyether-forming derivatives of these may also be used.

A preferred polyalkylene glycol copolymer (CP) is a copolymer composed of tetramethylene ether (tetramethylene glycol) units and units represented by the general formula (2A), particularly tetramethylene ether (tetra Methylene glycol) units and 2-methylethylene ether (propylene glycol) and/or (2-ethyl)ethylene glycol (butylene glycol) units are preferred. Also preferred are copolymers consisting of tetramethylene ether units and 2,2-dimethyltrimethylene ether units, ie neopentyl glycol ether units.

Methods for producing polyalkylene glycol copolymers (CP) having linear alkylene ether units (P1) and branched alkylene ether units (P2) are known, and include glycols, alkylene oxides, or their polyether-forming properties as described above. Derivatives can usually be prepared by polycondensation using an acid catalyst.

A polyalkylene glycol copolymer (CP) may be a random copolymer or a block copolymer.

The terminal groups of the polyalkylene glycol copolymer (CP) are preferably hydroxyl groups. Polyalkylene glycol copolymer (CP) has no effect on its performance even if one or both ends are blocked with alkyl ether, aryl ether, aralkyl ether, fatty acid ester, aryl ester, etc., etherified product or Esterates can be used as well.

The alkyl group constituting the alkyl ether may be linear or branched, and may be an alkyl group having 1 to 22 carbon atoms, such as methyl, ethyl, propyl, butyl, octyl, lauryl and stearyl. and the like. Preferred examples of alkyl ethers include methyl ether, ethyl ether, butyl ether, lauryl ether, and stearyl ether of polyalkylene glycol.

The aryl group constituting the aryl ether is preferably an aryl group having 6 to 22 carbon atoms, more preferably 6 to 12 carbon atoms, still more preferably 6 to 10 carbon atoms, such as phenyl, tolyl, and naphthyl groups. etc., and phenyl group, tolyl group and the like are preferable. The aralkyl group is preferably an aralkyl group having 7 to 23 carbon atoms, more preferably 7 to 13 carbon atoms, and still more preferably 7 to 11 carbon atoms, such as a benzyl group and a phenethyl group. Especially preferred.

The fatty acid that constitutes the fatty acid ester may be linear or branched, and may be saturated or unsaturated.

Fatty acids constituting fatty acid esters include monovalent or divalent fatty acids having 1 to 22 carbon atoms, such as monovalent saturated fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and enanthic acid. , caprylic acid, capric acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, heptadecyl acid, stearic acid, nonadecanic acid, arachidic acid, behenic acid, monovalent unsaturated fatty acids such as oleic acid, elaidic acid, Unsaturated fatty acids such as linoleic acid, linolenic acid, arachidonic acid, and divalent fatty acids having 10 or more carbon atoms, such as sebacic acid, undecanedioic acid, dodecanedioic acid, tetradecanedioic acid, thapsiic acid and decenedioic acid, undecene Diacids and dodecenedioic acids can be mentioned.

The aryl group constituting the aryl ester preferably has 6 to 22 carbon atoms, more preferably 6 to 12 carbon atoms, and still more preferably 6 to 10 carbon atoms, such as phenyl, tolyl, and naphthyl groups. etc., and phenyl group, tolyl group and the like are preferable. Even if the terminal-blocking group is an aralkyl group, it exhibits good compatibility with the polycarbonate resin (A), and can exhibit the same function as an aryl group. The aralkyl group is preferably an aralkyl group having 7 to 23 carbon atoms, more preferably 7 to 13 carbon atoms, and still more preferably 7 to 11 carbon atoms, such as a benzyl group and a phenethyl group. Especially preferred.

Polyalkylene glycol copolymers (CP) include, among others, copolymers composed of tetramethylene ether units and 2-methylethylene ether units, copolymers composed of tetramethylene ether units and 3-methyltetramethylene ether units, tetra Copolymers consisting of methylene ether units and 2,2-dimethyltrimethylene ether units are particularly preferred. Commercially available products of such polyalkylene glycol copolymers include "Polycerin DCB" (trade name) manufactured by NOF Corporation, "PTG-L" manufactured by Hodogaya Chemical Co., Ltd., "PTXG" manufactured by Asahi Kasei Fibers Co., Ltd., and the like. mentioned.

A copolymer consisting of tetramethylene ether units and 2,2-dimethyltrimethylene ether units can also be produced by the method described in JP-A-2016-125038.

As the polyalkylene glycol compound, a branched polyalkylene glycol compound represented by the following general formula (3A) or a linear polyalkylene glycol compound represented by the following general formula (3B) is also preferable. The branched polyalkylene glycol compound represented by the following general formula (3A) or the linear polyalkylene glycol compound represented by the following general formula (3B) is a copolymer with other copolymer components. may be used, but homopolymers are preferred.

In general formula (3A), R represents an alkyl group having 1 to 3 carbon atoms. Q ¹ and Q ² 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. r represents an integer of 10-400.

In general formula (3B), Q ³ and Q ⁴ each independently represent a hydrogen atom, an aliphatic acyl group having 2 to 23 carbon atoms or an alkyl group having 1 to 22 carbon atoms. p is an integer of 2-6 and q is an integer of 6-100.

In general formula (3A), the integer (degree of polymerization) r is 10-400, preferably 15-200, more preferably 20-100. If the degree of polymerization r is less than 10, a large amount of gas is generated during molding, and there is a possibility that defective molding due to gas, such as insufficient filling, gas burning, and poor transfer, may occur. If the degree of polymerization r exceeds 400, the effect of improving the hue of the polycarbonate resin composition pellets may not be sufficiently obtained.

Examples of branched polyalkylene glycol compounds include polypropylene glycol (poly(2-methyl)ethylene glycol) in which Q ¹ and Q ² are hydrogen atoms and R is a methyl group, and poly(poly(2-methyl)ethylene glycol) in which R is an ethyl group in general formula (3A). Butylene glycol (poly(2-ethyl)ethylene glycol) is preferred, and polybutylene glycol (poly(2-ethyl)ethylene glycol) is particularly preferred.

In general formula (3B), q (degree of polymerization) is an integer of 6-100, preferably 8-90, more preferably 10-80. If the degree of polymerization q is less than 6, gas is generated during molding, which is not preferable. If the degree of polymerization q exceeds 100, the compatibility is lowered, which is not preferable.

Examples of linear polyalkylene glycol compounds include polyethylene glycol in which Q ³ and Q ⁴ in general formula (3B) are hydrogen atoms and p is 2, polytrimethylene glycol in which p is 3, and p is 4. Polytetramethylene glycol, polypentamethylene glycol in which p is 5, and polyhexamethylene glycol in which p is 6 are preferred, and polytrimethylene glycol, polytetramethylene glycol, or esterified or etherified products thereof are more preferred. .

As the polyalkylene glycol compound, even if one or both ends are blocked with a fatty acid or alcohol, there is no effect on the performance expression, and fatty acid esters or ethers can be similarly used. Therefore, Q ¹ to Q ⁴ in general formulas (3A) and (3B) may be aliphatic acyl groups or alkyl groups having 1 to 23 carbon atoms.

As the fatty acid ester, either linear or branched fatty acid ester can be used. Fatty acids constituting the fatty acid ester may be saturated fatty acids or unsaturated fatty acids. Those in which some hydrogen atoms are substituted with substituents such as hydroxyl groups can also be used.

Fatty acids constituting fatty acid esters include monovalent or divalent fatty acids having 1 to 23 carbon atoms, such as monovalent saturated fatty acids, specifically formic acid, acetic acid, propionic acid, butyric acid, valeric acid, and caproic acid. , enanthic acid, caprylic acid, capric acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, heptadecyl acid, stearic acid, nonadecanic acid, arachidic acid, behenic acid, monovalent unsaturated fatty acids, specifically olein acids, unsaturated fatty acids such as elaidic acid, linoleic acid, linolenic acid, arachidonic acid, divalent fatty acids having 10 or more carbon atoms, specifically sebacic acid, undecanedioic acid, dodecanedioic acid, tetradecanedioic acid, thapsia Acids and decenedioic acids, undecenedioic acids, dodecenedioic acids can be mentioned.

Fatty acids can be used singly or in combination of two or more. Fatty acids also include fatty acids having one or more hydroxyl groups in the molecule.

Preferred specific examples of branched polyalkylene glycol fatty acid esters include polypropylene glycol stearate in which R is a methyl group, Q ¹ and Q ² are aliphatic acyl groups having 18 carbon atoms, and R is Polypropylene glycol behenate in which the methyl group, Q ¹ and Q ² are aliphatic acyl groups having 22 carbon atoms. Preferred specific examples of linear polyalkylene glycol fatty acid esters include polyalkylene glycol monopalmitate, polyalkylene glycol dipalmitate, polyalkylene glycol monostearate, polyalkylene glycol distearate, and polyalkylene glycol. Examples thereof include (monopalmitic acid/monostearic acid) esters and polyalkylene glycol behenates.

The alkyl group constituting the alkyl ether of polyalkylene glycol may be linear or branched, and may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a lauryl group, a stearyl group, or the like. 1 to 23 alkyl groups are included. As the polyalkylene glycol compound, alkylmethyl ether, ethyl ether, butyl ether, lauryl ether, stearyl ether and the like of polyalkylene glycol are preferably exemplified.

Commercially available products of the branched polyalkylene glycol compound represented by the general formula (3A) include “Uniol D-1000” and “Uniol PB-1000” (trade names manufactured by NOF Corporation).

Number of polyalkylene glycol compounds such as polyalkylene glycol copolymer (CP), branched polyalkylene glycol compound represented by general formula (3A), and linear polyalkylene glycol compound represented by general formula (3B) The average molecular weight is preferably 200 to 5,000, more preferably 300 or more, still more preferably 500 or more, more preferably 4,000 or less, still more preferably 3,000 or less, particularly preferably 2000 or less, particularly preferably 1000 less than and most preferably 800 or less. If the number average molecular weight exceeds the above upper limit, the compatibility tends to decrease. If the number average molecular weight is less than the above lower limit, gas tends to be generated during molding. The number average molecular weight of the polyalkylene glycol compound is the number average molecular weight calculated based on the hydroxyl value measured according to JIS K1577.

These polyalkylene glycol compounds may be used singly or in combination of two or more.

When the pellets of the present invention contain a polyalkylene glycol compound, the content varies depending on the type of polyalkylene glycol compound used, but is preferably 0.001 to 1.0% by mass, and 0.1 to 0.1% by mass. 0.5 mass % is more preferred. When the content of the polyalkylene glycol compound is less than the above lower limit or exceeds the above upper limit, the hue of the resulting molded article tends to be poor.

<Method for producing polycarbonate resin composition pellets>
A method for producing the pellets of the present invention includes, for example, a method in which each component is blended collectively or separately, melt-kneaded, and pelletized. Here, the blending amount of each component is the aromatic alcohol (B) in the pellets obtained, the phosphorus stabilizer (C), and the epoxy compound (D) and / or oxetane compound (E ) is adjusted so that it falls within the aforementioned range or preferred range of the present invention. That is, when melt-kneading the polycarbonate resin composition, depending on the melt-kneading temperature, the blended aromatic alcohol (B), phosphorus-based stabilizer (C), epoxy compound (D), oxetane compound (E), etc. The content of the pellets obtained does not necessarily match the amount of the components blended for the preparation of the polycarbonate resin composition, but in the present invention, the pellets obtained Aromatic alcohol (B), phosphorus stabilizer (C), epoxy compound (D), and oxetane compound (E) are blended so that the contents are the above-mentioned contents. Examples of the method of blending each component include a method of using a tumbler, a Henschel mixer, etc., and a method of quantitatively supplying the components to a hopper of an extruder using a feeder for mixing. For melt-kneading, it is preferable to use, for example, a single-screw kneading extruder or a twin-screw kneading extruder. After being transported in a water tank and cooled, the pellets of the aromatic polycarbonate resin composition can be obtained by cutting into a predetermined size with a pelletizer.

[Molding]
The molded article of the present invention is obtained by molding the pellet of the present invention.

The method for molding the pellets of the present invention is not particularly limited, but examples thereof include injection molding, compression molding, injection compression molding and the like, with injection molding being preferred.

In order to suppress thermal deterioration of the resin during molding and obtain an excellent hue, it is preferable to mold the pellets of the present invention in an atmosphere of an inert gas such as nitrogen.

The molded article of the present invention obtained by molding the pellet of the present invention has a remarkably good hue compared to conventional products. It can be suitably used as a light guide member of an automotive lighting device that is exposed to heating conditions even with high heat. The replacement frequency of members can be greatly reduced.

[YI value]
The pellets of the present invention are remarkably excellent in hue, and a 300 mm length measured for a 300 mm long optical path molded product obtained by injection molding using the pellets of the present invention according to the method described in the Examples section below. The YI value of is usually about 16 or less, preferably 15 or less, more preferably 14 or less, and exhibits remarkably excellent hues not found in conventional products.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Materials used in Examples and Comparative Examples are as follows.

<Polycarbonate resin (A)>
A1: "Iupilon (registered trademark) H-4000F" manufactured by Mitsubishi Engineering-Plastics Co., Ltd.: Bisphenol A type aromatic polycarbonate resin produced by an interfacial polymerization method (viscosity average molecular weight 15,000)

<Aromatic Alcohol (B) Represented by Formula (1)>
B1: Tokyo Ohka Kogyo Co., Ltd. "benzyl alcohol S": benzyl alcohol B2: Mitsubishi Gas Chemical Co., Ltd. "biphenyl methanol": 4-phenylbenzyl alcohol B3: Tokyo Chemical Industry Co., Ltd.: 2-methylphenyl methanol B4: Tokyo Kasei Industrial: 4-methylphenylmethanol B5: Tokyo Chemical Industry: 4-tert-butylphenylmethanol B6: Tokyo Chemical Industry: 1,4-benzenedimethanol

<Other aromatic alcohols (b)>
b1: Tokyo Chemical Industry: 2-methoxyphenylmethanol b2: Tokyo Chemical Industry: 4-methoxyphenylmethanol b3: Tokyo Chemical Industry: 2,3-dimethoxyphenylmethanol b4: Tokyo Chemical Industry: 3,4,5 -Trimethoxyphenylmethanol b5: Tokyo Chemical Industry: 3-phenoxyphenylmethanol b6: Tokyo Chemical Industry: α-methylphenylmethanol b7: Tokyo Chemical Industry: α,α-dimethylphenylmethanol

<Phosphorus stabilizer (C)>
<Phosphite Stabilizer (C-I)>
C1: "Doverphos S-9228" manufactured by Properties & Characteristics: Bis (2,4-dicumylphenyl) pentaerythritol diphosphite C3: "Adekastab PEP-36" manufactured by ADEKA: bis (2,6-di-tert-butyl -4-methylphenyl)pentaerythritol diphosphite
<Phosphite Stabilizer (C-II)>
C2: ADEKA "adekastab AS2112": tris (2,4-di-tert-butylphenyl) phosphite

<Epoxy compound (D)>
D1: "Celoxide 2021P" manufactured by Daicel Corporation: 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate

<Oxetane compound (E)>
E1: Toagosei Co., Ltd. "Aron oxetane OXT-221": 3-ethyl-3 {[(3-ethyloxetan-3-yl) methoxy] methyl} oxetane

<Polyalkylene glycol (X)>
X1: "PEG#1000" manufactured by Wako Pure Chemical Industries, Ltd.: polyethylene glycol (number average molecular weight 600)
X2: NOF Corporation "Uniol D-2000": Polypropylene glycol (number average molecular weight 2000)
X3: NOF Corporation "Uniol PB-700": polybutylene glycol (number average molecular weight 700)

[Examples 1 to 37 and Comparative Examples 1 to 14]
<Production of polycarbonate resin composition pellets>
Polycarbonate resin (A) and the components shown in Tables 1A, 1B, and Tables 2 to 5 were blended in predetermined proportions and uniformly mixed in a tumbler mixer to obtain a mixture. This mixture is supplied to a single screw extruder ("VS-40" manufactured by Isuzu Kakoki Co., 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. and extruded in a strand form from the tip of the extrusion nozzle. The extrudate was quenched in a water bath, cut and pelletized using a pelletizer to obtain polycarbonate resin composition pellets.
The obtained pellets were analyzed and evaluated as follows.

<Analysis of content of each component in pellet>
The contents of aromatic alcohol (B), aromatic alcohol (b), phosphorus-based stabilizer (C), epoxy compound (D), and oxetane compound (E) in the pellets were obtained by the following GC measurement. The content of polyalkylene glycol (X) in the pellet was determined by the NMR measurement below.

<GC measurement>
A dichloromethane solution of the pellets was prepared, acetone was added dropwise to reprecipitate the polymer component, and the solution was filtered, and the concentrated filtrate was dissolved in 5 ml of dichloromethane. This dichloromethane solution was analyzed by gas chromatography ("GC-2010" manufactured by Shimadzu Corporation) equipped with a capillary column (UA-1). The gas chromatography inlet temperature was 275° C., the detector temperature was 350° C., the column temperature was raised from 50° C. to 350° C., and the final temperature was maintained for 5 minutes. Using a calibration curve prepared from a standard substance prepared separately, the content in the pellet was calculated from the above measurement results,

<NMR measurement>
The pellet was dissolved in heavy tetrachloroethane, sealed in a special sample tube, and subjected to ¹ H NMR spectrum measurement using a nuclear magnetic resonance apparatus ("AVANCE III 500" manufactured by BRUKER). The content was calculated.

<Evaluation of Hue (YI)>
After drying the pellets at 120 ° C for 4 to 8 hours with a hot air circulation dryer, an injection molding machine ("EC100" manufactured by Toshiba Machine Co., Ltd.) is used at a temperature of 280 ° C to form a 300 mm long optical path molded product (6 mm × 4 mm × 300 mm , L/d=50) were molded. For this molded article, the YI value of 300 mm length was measured using a long-path spectral transmission colorimeter (“ASA1” manufactured by Nippon Denshoku Industries Co., Ltd.).

These results are shown in Tables 1A, 1B and Tables 2-5.

Tables 1A, 1B and 2 show the following.
Comparative Example 1, which contains the phosphorus stabilizer (C) but does not contain the aromatic alcohol (B), is inferior in hue (YI).
Comparative Examples 2 to 5, in which polyalkylene glycol (X) was used instead of aromatic alcohol (B), were also improved in hue compared to Comparative Example 1, but were inferior to those of Examples.
Further, even with the same aromatic alcohol, the substituents substituted on the benzene ring are not alkyl groups or aryl groups but alkoxy groups or phenoxy groups. 10 and Comparative Examples 11 and 12 using the aromatic alcohols (b6) and (b7) in which the hydrogen atoms of the hydroxymethyl groups were substituted with alkyl groups, the effect of improving the hue was not obtained, and the aromatic alcohol was blended. As a result, the hue is inferior to that of Comparative Example 1, which does not.
On the other hand, the pellets of Examples 1 to 19 containing the aromatic alcohol (B) and the phosphorus-based stabilizer (C) represented by the general formula (1) have extremely good hue (YI), Furthermore, it turns out that a hue can be improved more by containing an epoxy compound (D).
In Examples 34 and 36, the oxetane compound (E) was used instead of the epoxy compound (D), and in Examples 35 and 37, the epoxy compound (D) and the oxetane compound (E) were used in combination. Similar to the case of using (D), the effect of improving the hue is obtained.
From the comparison between Examples 2, 4, 6, and 9 and Comparative Examples 2 to 4, and between Examples 3 and 7 and Comparative Examples 5 and 14, aromatic alcohol (B) is less than polyalkylene glycol (X). It can be seen that the effect of improving the hue can be obtained depending on the content.
The same is clear from comparison between Examples 20 to 25 and Comparative Example 13 in Table 3. That is, Examples 20 to 25 containing both the phosphorus stabilizer (C) and the aromatic alcohol (B) are clearly improved in hue (YI) with respect to Comparative Example 13 containing no aromatic alcohol (B). ing. Further, from the comparison between Example 20 and Example 21, the comparison between Example 22 and Example 23, and the comparison between Example 24 and Example 25, it was found that by further containing the epoxy compound (D), the hue was changed. It turns out that more can be improved.

Examples 26 to 31 in Table 4 contain polyalkylene glycol (X) together with aromatic alcohol (B) and phosphorus-based stabilizer (C). Obtainable.
Table 5 shows that a benzenedimethanol-based compound was used instead of a benzyl alcohol-based compound as the aromatic alcohol (B), and although slightly inferior to the case of using a benzyl alcohol-based compound, the effect of improving hue was obtained. there is

[Heat aging evaluation]
In Examples 1, 7, 21, and Comparative Examples 3, 14, a 300 mm long optical path molded product ( 6 mm×4 mm×300 mm, L/d=50) was heat-treated at 120° C. for 500 hours using a hot air dryer (Espec PHH-102). The hue (YI) before and after heat treatment is measured with a YI value of 300 mm length using a long-path spectral transmission colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd. "ASA1"), and the hue difference (ΔYI) before and after treatment. asked. Table 6 shows the results.

From Table 6, it can be seen that the inclusion of the aromatic alcohol (B) can improve the hue not only before the heat treatment but also after the heat treatment, and can reduce the hue difference (ΔYI).

Claims (5)

A polycarbonate resin composition pellet containing a polycarbonate resin (A), an aromatic alcohol (B) represented by the following general formula (1), and a phosphorus stabilizer (C),
The phosphorus-based stabilizer (C) comprises a phosphite-based stabilizer (C-I) having a spiro ring skeleton and a phosphite-based stabilizer (C-II) represented by the following general formula (II),
The content ratio by mass of the phosphite-based stabilizer (C-I) and the phosphite-based stabilizer (C-II) is 1:1 to 15,
A polycarbonate characterized in that the content of the aromatic alcohol (B) in the pellets is 0.001 to 1% by mass and the content of the phosphorus stabilizer (C) is 0.003 to 0.5% by mass. resin composition pellets;

(In the general formula (1), X represents an alkyl group or an optionally substituted aryl group. n represents an integer of 0 to 4, and when n is 2 or more, n X is may be the same or different, k is 1 or 2.)

(In Formula (II), R ²⁵ to R ²⁹ each independently represent a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.) 2. The polycarbonate resin composition pellet according to claim 1 , wherein the aromatic alcohol (B) represented by the general formula (1) is represented by the following general formula (1A).

(In general formula (1A), X, Y, and n have the same definitions as in general formula (1).) The aromatic alcohol (B) is benzyl alcohol (phenylmethanol), 4-phenylbenzyl alcohol (4-phenylphenylmethanol), 2-methylphenylmethanol, 4-methylphenylmethanol, 4-tert-butylphenylmethanol and 1 3. The polycarbonate resin composition pellet according to claim 1, wherein the polycarbonate resin composition pellet is one or more selected from the group consisting of , 4-benzenedimethanol. 4. The polycarbonate resin composition pellet according to any one of claims 1 to 3 , further comprising 0.01 to 0.5% by mass of an epoxy compound (D). A molded article obtained by molding the polycarbonate resin composition pellet according to any one of claims 1 to 4 .