WO2020183834A1 - Polycarbonate resin composition for optical member - Google Patents

Abstract

This resin composition contains, with respect to 100 parts by mass of an aromatic polycarbonate resin (A): 0.1-3 parts by mass of a polyoxytetramethylene glycol-based multidimensional polymer (B); and 0.005-0.4 parts by mass of a phosphorus stabilizer (C). The polycarbonate resin composition for an optical member is characterized in that the polyoxytetramethylene glycol-based multidimensional polymer (B) is a multidimensional polymer having a structure in which polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are bonded via an alkylene diol (B2) and has a number average molecular weight (Mn) of 1,000-3,000.

Description

Polycarbonate resin composition for optical members

The present invention relates to a polycarbonate resin composition for an optical member, and more particularly to a polycarbonate resin composition for an optical member having low thermal stability, heat-resistant discoloration, and low chargeability.

Polycarbonate resin is excellent in transparency, mechanical properties, thermal properties, electrical properties, weather resistance, etc., and is used for optical members such as light guide plates. However, since the hue of the polycarbonate resin is colored yellower than that of polymethylmethacrylate or the like, a planar light source device or the like using the light guide plate of the polycarbonate resin has a problem that the chromaticity difference in the light guide plate is large. Therefore, a light guide plate made of a polycarbonate resin or the like is required to improve brightness and light transmittance and to reduce coloring due to oxidation.

Patent Document 1 provides a polycarbonate resin composition for a light guide plate, which does not impair the original characteristics of an aromatic polycarbonate resin, does not cause cloudiness or decrease in permeability, and has good permeability and hue. For the purpose, an aromatic polycarbonate resin composition for a light guide plate containing 0.01 to 1 part by weight of polyalkylene glycol in an aromatic polycarbonate resin is disclosed.

However, the compatibility of polyalkylene glycol with the polycarbonate resin is not always sufficient, so that the obtained light guide plate tends to be cloudy, the transparency tends to deteriorate, and the hue tends to deteriorate.

In particular, in various liquid crystal display devices, thinning and large-sized thinning are progressing at a remarkable speed, and an edge type that allows light to enter the light guide plate from the direct type to the lateral edge has come to be adopted. Optical members such as light guide plates are required to have a higher degree of transparency and hue. This requirement becomes even more stringent especially in the case of an optical member having a long optical path length, for example, an optical member having an optical path length of 50 mm or more.

The applicant has described in Patent Document 2 a copolymerized polycarbonate glycol containing 40 to 80 mol% of tetramethylene glycol unit, 5 to 45 mol% of (2-methyl) ethylene glycol unit, and 5 to 50 mol% of ethylene glycol unit. It was proposed that the polycarbonate resin composition contained therein is excellent in transparency, heat-resistant discoloration, and releasability.

Japanese Unexamined Patent Publication No. 2004-051700 Japanese Unexamined Patent Publication No. 2018-203985

However, it has been found that the polycarbonate resin composition proposed in Patent Document 2 has a problem that the unit derived from ethylene glycol has poor thermal stability and is easily charged (easily dusted).
An object (problem) of the present invention is to provide a polycarbonate resin composition for an optical member, which is excellent in thermal stability and charging characteristics (hard to be charged) without impairing the original characteristics of the polycarbonate resin.

As a result of diligent studies to achieve the above problems, the present inventor has a polyoxytetramethylene glycol-based structure in which a polyoxytetramethylene glycol-based random polymer component is bonded via an alkylene diol (B2). We have found that the above problems can be solved by containing a copolymer, and have completed the present invention.
The present invention relates to the following polycarbonate resin compositions for optical members and molded products.

[1] With respect to 100 parts by mass of the aromatic polycarbonate resin (A), 0.1 to 3 parts by mass of the polyoxytetramethylene glycol-based multiplex polymer (B) and 0.005 to 0 parts of the phosphorus-based stabilizer (C) A resin composition containing 4 parts by mass.
A polyoxytetramethylene glycol-based multi-component polymer (B) is a multi-component polymer having a structure in which polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are bonded via an alkylene diol (B2). A polycarbonate resin composition for an optical member, which has a number average molecular weight (Mn) of 1000 to 3000.
[2] The polycarbonate for an optical member according to the above [1], wherein the alkylene diol (B2) is the diol component having the lowest content among all the diol components constituting the polyoxytetramethylene glycol-based multi-element polymer (B). Resin composition.
[3] The polyoxytetramethylene glycol-based multi-element polymer (B) contains 10 mol% or less of units derived from the alkylene diol (B2) in all the diol components constituting the multi-element polymer (B). The polycarbonate resin composition for an optical member according to the above [1] or [2], wherein the mass ratio of the content of the unit derived from oxytetramethylene glycol is 55 to 80% by mass.
[4] The alkylene diol (B2) is an alkylene diol monomer in which the main chain may be branched with 2 to 6 carbon atoms, or any of the above [1] to [3] which is a dimer thereof. The polycarbonate resin composition for an optical member described in Crab.
[5] The above [1] to which the alkylene diol (B2) is ethylene glycol, 2- (methyl) ethylene glycol, (2-ethyl) ethylene glycol, trimethylene glycol, neopentyl glycol, or a dimer thereof. The polycarbonate resin composition for an optical member according to any one of [4].

[6] Polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are random copolymers containing oxytetramethylene glycol units and other oxyalkylene glycol units other than oxytetramethylene glycol units. The polycarbonate resin composition for an optical member according to any one of the above [1] to [5].
[7] The oxyalkylene glycol units other than the oxytetramethylene glycol units in the polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are ethylene glycol, (2-methyl) ethylene glycol, trimethylene glycol, and the like. The polycarbonate resin composition for an optical member according to any one of the above [1] to [6], which is selected from the units derived from (2-ethyl) ethylene glycol.
[8] Polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are copolymers containing oxytetramethylene glycol units and oxy (2-methyl) ethylene glycol units, and are alkylene diols (B2). The polycarbonate resin composition for an optical member according to any one of the above [1] to [7], wherein) is ethylene glycol or diethylene glycol.
[9] Further, the above [1] to [8] containing 0.005 to 0.2 parts by mass of the epoxy compound and / or the oxetane compound (D) with respect to 100 parts by mass of the aromatic polycarbonate resin (A). The polycarbonate resin composition for an optical member according to any one.
[10] A molded product for an optical member comprising the polycarbonate resin composition according to any one of the above [1] to [9].
[11] The molded product according to the above [10], wherein the molded product is a light guide for automobile lighting, a light guide for lighting, or a light guide plate for a backlight having an optical path length of 50 mm or more of an optical component.
[12] A polyoxytetramethylene glycol-based multipolymer obtained by addition polymerization of tetrahydrofuran and other alkylene oxides with alkylenediol (B2) as an initiator with respect to 100 parts by mass of the aromatic polycarbonate resin (A). A method for producing a polycarbonate resin composition for an optical member, which comprises 0.1 to 3 parts by mass of B) and 0.005 to 0.4 parts by mass of a phosphorus-based stabilizer (C).

The polycarbonate resin composition of the present invention is excellent in thermal stability, heat-resistant discoloration and antistatic properties (antistatic properties) without impairing the original properties of the polycarbonate resin, and thus is suitably used for various optical members. Can be done.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples.
In addition, in this specification, "-" is used in the meaning which includes the numerical values described before and after it as the lower limit value and the upper limit value unless otherwise specified.

The polycarbonate resin composition for an optical member of the present invention contains 100 parts by mass of an aromatic polycarbonate resin (A) and 0.1 to 3 parts by mass of a polyoxytetramethylene glycol-based multiplex polymer (B) and a phosphorus-based stabilizer. A resin composition containing 0.005 to 0.4 parts by mass of (C).
A polyoxytetramethylene glycol-based multi-component polymer (B) is a multi-component polymer having a structure in which polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are bonded via an alkylene diol (B2). It is characterized in that the number average molecular weight (Mn) is 1000 to 3000.

[Aromatic Polycarbonate Resin (A)]
The polycarbonate resin composition of the present invention contains an aromatic polycarbonate resin (A).
The aromatic polycarbonate resin (A) is an aromatic polycarbonate polymer obtained by reacting an aromatic hydroxy compound with a phodiester 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 conventional methods such as a phosgene method (interfacial polymerization method) and a melting method (transesterification method) can be used.

Typical examples of aromatic dihydroxy compounds 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-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 And so on.

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

When producing the aromatic polycarbonate resin (A), a small amount of polyhydric phenol or the like 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 the polyhydric phenol having three or more hydroxy groups include fluoroglucolcin, 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) hepten-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) oxyindole (ie, isatin bisphenol), 5-chloruisatin, 5,7- Examples thereof include dichlorousatin and 5-bromuisatin. Of these, 1,1,1-tris (4-hydroxyphenyl) ethane or 1,3,5-tris (4-hydroxyphenyl) benzene is preferable. 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.

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

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

When producing an aromatic polycarbonate resin by the transesterification method, a catalyst is usually used. The type of catalyst is not limited, but generally, basic compounds such as alkali metal compounds, alkaline earth metal compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds are used. Of these, alkali metal compounds and / or alkaline earth metal compounds are particularly preferable. These may be used alone or in combination of two or more. In the transesterification method, it is common to inactivate the catalyst with a p-toluenesulfonic acid ester or the like.

The viscosity average molecular weight of the aromatic polycarbonate resin (A) is preferably 10,000 to 30,000.
For a light guide plate such as a backlight for a liquid crystal, it is preferably 10,000 to 15,000, more preferably 10,500 or more, still more preferably 11,000 or more, particularly 11,500 or more, and most preferably 12. It is 000 or more, more preferably 14,000 or less.
Further, 15,000 to 23,000 is preferable for light guides and lenses that guide light from a light source such as an LED in a headlamp (head lamp) for a vehicle such as an automobile or a motorcycle, and fluidity. It is more preferably 17,000 to 20,000 in terms of hue.
Further, in a light guide for lighting or the like, it is preferably 15,000 to 24,000, and more preferably 17,000 to 20,000 from the viewpoint of fluidity and hue.

By setting the viscosity average molecular weight to the lower limit of the above range or more, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, and by setting the viscosity average molecular weight to the upper limit of the above range or less, the present invention It is possible to suppress and improve the decrease in fluidity of the polycarbonate resin composition of the present invention, improve the molding processability, and facilitate the molding process.
Two or more kinds of aromatic polycarbonate resins having different viscosity average molecular weights may be mixed and used. In this case, a polycarbonate resin having a viscosity average molecular weight outside the above-mentioned suitable range may be mixed.

For the viscosity average molecular weight [Mv] of the aromatic polycarbonate resin (A), methylene chloride was used as a solvent, and the ultimate viscosity [η] (unit: dl / g) at a temperature of 25 ° C. was determined using an Ubbelohde viscometer. , Schnell's viscosity formula, η = 1.23 × 10 ^-4 Mv ^0.83 means a value calculated from. The ultimate viscosity [η] is a value calculated by the following formula by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

The terminal hydroxyl group concentration of the aromatic polycarbonate resin (A) is arbitrary and may be appropriately selected and determined, but is usually 1000 ppm or less, preferably 800 ppm or less, and more preferably 600 ppm or less. Thereby, the retention heat stability and the color tone of the polycarbonate resin can be further improved. Further, the lower limit thereof is usually 10 ppm or more, preferably 30 ppm or more, and more preferably 40 ppm or more, particularly in the case of the polycarbonate resin produced by the melt transesterification method. As a result, it is possible to suppress a decrease in molecular weight and further improve the mechanical properties of the resin composition.

The unit of the terminal hydroxyl group concentration is the mass of the terminal hydroxyl group expressed in ppm with respect to the mass of the polycarbonate resin. The measuring method is colorimetric quantification by the titanium tetrachloride / acetic acid method (the method described in Macromol. Chem. 88 215 (1965)).

The aromatic polycarbonate resin is not limited to a mode containing only one type of polycarbonate resin, and includes, for example, a mode containing a plurality of types of polycarbonate resins having different monomer compositions and molecular weights. It may be used in combination with an alloy (mixture) of a polycarbonate resin and another thermoplastic resin. Further, for example, a polycarbonate resin is a copolymer of an oligomer or a polymer having a siloxane structure for the purpose of further improving flame retardancy and impact resistance; a phosphorus atom for the purpose of further improving thermal oxidation stability and flame retardancy. Copolymer with a monomer, oligomer or polymer having a dihydroxyanthraquinone structure; a copolymer with a monomer, oligomer or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermal oxidation stability; polystyrene or the like to improve the optical properties. Even if it is configured as a copolymer mainly composed of a polycarbonate resin, such as a copolymer with an oligomer or a polymer having an olefin structure; a copolymer with a polyester resin oligomer or a polymer for the purpose of improving chemical resistance; Good.

Further, the aromatic polycarbonate resin may contain a polycarbonate oligomer in order to improve the appearance and fluidity of the molded product. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1500 or more, preferably 2000 or more, and usually 9500 or less, preferably 9000 or less. Further, the contained polycarbonate ligomer is preferably 30% by mass or less of the aromatic polycarbonate resin (including the polycarbonate oligomer).

Further, the aromatic polycarbonate resin may be not only a virgin raw material but also a polycarbonate resin recycled from a used product (so-called material recycled polycarbonate resin).
However, the regenerated polycarbonate resin is preferably 80% by mass or less, and more preferably 50% by mass or less of the aromatic polycarbonate resin. Since the regenerated polycarbonate resin is likely to be deteriorated by heat deterioration, aging deterioration, etc., if such a polycarbonate resin is used in a larger amount than the above range, the hue and mechanical properties can be deteriorated. Because there is sex.

[Polyoxytetramethylene glycol-based multipolymer (B)]
The polycarbonate resin composition for an optical member of the present invention is a polyoxytetramethylene glycol-based composition having a structure in which polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are bonded via an alkylene diol (B2). Contains the multi-dimensional polymer (B).

The polymer (B) preferably has a structure represented by the following formula (1).
YXY'(1)
In the above formula (1), X is a residue obtained by removing the hydroxyl group from the alkylene diol (B2), and Y and Y'are polyoxytetramethylene glycol-based random polymer components (B1) and (B3). , Each may be the same or different.
As a structural example of the above formula (1), when an alkylene diol component having poor thermal stability such as ethylene glycol or diethylene glycol is introduced into X, the polymer (compared to the case where those alkylene diols are introduced into the terminal structure). It is preferable because the decomposition of B) is unlikely to occur and the thermal stability becomes more excellent.

As the alkylene diol (B2), preferably, an alkylene diol monomer in which the number of carbon atoms in the main chain may be branched at 2 to 6 or a dimer thereof is used.

Preferred examples of the linear alkylene glycol having 2 to 6 carbon atoms in the main chain include ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, and the like, and these are two types even if one type is used alone. The above mixture may be used.
Of these, ethylene glycol and trimethylene glycol are particularly preferable.

Branched alkylene glycols having 2 to 6 carbon atoms in the main chain include (2-methyl) ethylene glycol, (2-ethyl) ethylene glycol, (2-methyl) trimethylene glycol, and (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 (ie, neopentyl glycol), (3,3-dimethyl) trimethylene glycol, (3,3-methylethyl) trimethylene glycol, (3,3-diethyl) trimethylene 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, (4,4-methylethyl) tetramethylene glycol, (4,4-diethyl) tetramethylene glycol, ( 3-Methyl) pentamethylene glycol, (4-methyl) pentamethylene glycol, (5-methyl) pentamethylene glycol, (3-ethyl) pentamethylene glycol, (4-ethyl) pentamethylene glycol, (5-ethyl) penta Methylene 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, (4,5-diethyl) pentamethylene glycol, (5,5-dimethyl) pentamethylene glycol, (5,5-methylethyl) pentamethylene glycol, (5,5-diethyl) ) Pentamethylene glycol and the like. These may be one kind alone or a mixture of two or more kinds.
Among the above, as the branched alkylene glycol, (2-methyl) ethylene glycol, (2-ethyl) ethylene glycol, and (2-methyl) trimethylene glycol are preferable.

Specific examples of the alkylene diol dimer in which the main chain of the alkylene diol (B2) may be branched at 2 to 6 carbon atoms are preferably diethylene glycol, dipropylene glycol, dineopentyl glycol and the like. Be done.

Among the above-mentioned alkylene diols (B2), ethylene glycol, (2-methyl) ethylene glycol, trimethylene glycol, (2-ethyl) ethylene glycol, neopentyl glycol, and dimers thereof are particularly preferable. Of these, diethylene glycol and dineopentyl glycol are particularly preferable as dimers.

The alkylene diol (B2) may be used alone or in combination of two or more. Further, as the alkylene diol (B2), a small amount of the alicyclic diol compound and the aromatic diol may be used in combination as long as the effects of the present invention are not impaired. When the alicyclic diol compound and / or the aromatic diol is used in combination, the amount is based on 100% by mass of the total of the alkylene diol (B2), the alicyclic diol compound and the aromatic diol, preferably less than 5% by mass. It is preferably less than 3% by mass, particularly less than 2% by mass, particularly less than 1% by mass.

Examples of the alicyclic diol compound include cyclobutanediols such as 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,4-cyclohexanediol, 1,2-cyclohexanediol, and 1,3-cyclohexane. Diols, cyclohexanediols such as 2-methyl-1,4-cyclohexanediol, cyclohexanedimethanols such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2, Norbornane diethanols such as 2-bis (4-hydroxycyclohexyl) propane (ie, hydride bisphenol A), 2,3-norbornandimethanol, 2,5-norbornandimethanol, tricyclodecanedimethanol, pentacyclopentadecane. Dimethanol, 1,3-adamantandiol, 2,2-adamantandiol, decalin dimethanol, 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] Undecan and the like can be mentioned.

Among the above, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, cyclohexanediols, cyclohexanedimethanol, 2,2-bis (4-hydroxycyclohexyl) propane (ie, hydrogen) Bisphenol A) is more preferred, especially 2,2-bis (4-hydroxycyclohexyl) propane (ie, bisphenol A hydride).

Examples of the aromatic diol include bisphenol A, 4,4'-methylenediphenol, bisphenol A, 4,4'-dihydroxybiphenyl and the like.

The polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are a polymer component having an oxytetramethylene glycol unit [-CH ₂ CH ₂ CH ₂ CH _2- O-] and an oxytetramethylene glycol unit. It is a random copolymer component having other oxyalkylene glycol units other than the above.

The other oxyalkylene glycol unit may be either a linear type or a branched type oxyalkylene glycol unit. The number of carbon atoms in the oxyalkylene glycol unit is preferably 2 to 20, more preferably 2 to 16, further preferably 2 to 12, and particularly preferably 2 to 10.

Examples of the linear oxyalkylene glycol unit include ethylene glycol, trimethylene glycol, pentamethylene glycol, and hexamethylene glycol as alkylene glycols. These may be one kind alone or a mixture of two or more kinds.
Of the above, ethylene glycol and trimethylene glycol are more preferable.

Examples of branched oxyalkylene glycol units include (2-methyl) ethylene glycol, (2-ethyl) ethylene glycol, (2-methyl) trimethylene glycol, and (3-methyl) as alkylene glycols. Trimethylene glycol, (2-ethyl) trimethylene glycol, (3-ethyl) triethylene glycol, (2,2-dimethyl) trimethylene glycol, (2,2-methylethyl) trimethylene glycol, (2,2- Diol (diethyl) trimethylene glycol (ie, neopentyl glycol), dineopentyl glycol, (3,3-dimethyl) trimethylene glycol, (3,3-methylethyl) trimethylene glycol, (3,3-diethyl) trimethylene 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, (4,4-methylethyl) tetramethylene glycol, (4,4- Diethyl) tetramethylene 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.
These may be one kind alone or a mixture of two or more kinds.
Of the above, more preferred are (2-methyl) ethylene glycol, (2,2-diethyl) trimethylene glycol (ie, neopentyl glycol), and (3-methyl) tetramethylene glycol.

Although the oxyalkylene glycol unit has been described above by taking glycol as an example for convenience, the oxyalkylene glycol unit is not limited to these glycols, and may be these alkylene oxides or their polyether-forming derivatives.

The polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are oxytetramethylene glycol units, ethylene glycol other than oxytetramethylene glycol, (2-methyl) ethylene glycol, trimethylene glycol, and neopentyl glycol. , A random copolymer composed of (2-methyl) tetramethylene glycol units is more preferable, and a random copolymer composed of trimethylene glycol, (2-methyl) ethylene glycol, and (2-methyl) ethylene glycol units is particularly preferable.

Since the polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are random copolymers, they are aromatic because they suppress the crystallization of the polyoxytetramethylene glycol-based multiplex polymer (B). Compatibility with the polycarbonate resin (A) and handleability are improved. Further, the compatibility with the polycarbonate resin is further improved by the polyoxytetramethylene glycol-based multi-component polymer (B) in which this is bonded with an alkylene diol (B2).

The polymer (B) can be produced by a known method. For example, a glycol that forms the above-mentioned oxyalkylene glycol unit in the presence of an alkylene diol (B2), or an alkylene oxide or a polyether-forming derivative thereof can be prepared by a known method described in, for example, JP-A-2018-184557. , It can be produced by polymerizing with an alkylene diol (B2) as an initiator in the presence of a Lewis acid catalyst under appropriate reaction conditions.
Preferably, it can be produced by addition polymerization of tetrahydrofuran and an alkylene oxide forming an oxyalkylene glycol unit other than the oxytetramethylene glycol unit using the alkylene diol (B2) as an initiator.

In the polymer (B), the amount of the alkylenediol (B2) component to which the polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are bonded is the amount of the polyoxytetramethylene glycol-based multiplex polymer (B). Of all the diol components constituting the above, the content is preferably the smallest, and the content is preferably 10 mol% or less, more preferably 8 mol% or less, still more preferably 7 mol% or less, and particularly preferably 5 mol. % Or less, preferably 1 mol% or more, more preferably 2 mol% or more, still more preferably 3 mol% or more.
When the alkylenediol (B2) component is not more than the above upper limit value, the thermal stability of the polymer (B) becomes good, and when it exceeds the above upper limit value, the molecular chain length is shortened, so that the heat of the polymer (B) is increased. Stability is reduced and a large amount of mold deposits are likely to occur.
Here, the mol% when the alkylene diol (B2) is a dimer such as diethylene glycol or dineopentyl glycol is calculated assuming that the number of moles of the dimer is 2 mol.

In the polymer (B), the mass ratio of the content of the unit derived from oxytetramethylene glycol is preferably 55 to 80% by mass.
When the mass ratio of the oxytetramethylene glycol unit is 55 to 80% by mass, the compatibility with the aromatic polycarbonate resin (A) becomes good, and when it is less than 55% by mass or exceeds 80% by mass, it is aromatic. The compatibility with the polycarbonate resin (A) tends to deteriorate.
The amount of the oxytetramethylene glycol unit is preferably 56% by mass or more, more preferably 57% by mass or more, preferably 75% by mass or less, more preferably 70% by mass or less, still more preferably 65% by mass. % Or less, particularly preferably 63% by mass or less.
Further, in the polymer (B), the mass ratio of the units other than oxytetramethylene glycol in the components excluding the alkylenediol (B2) component is preferably 20 to 47% by mass, more preferably 30% by mass. As described above, it is preferably 43% by mass or less, more preferably 40% by mass or less, and particularly preferably 38% by mass or less.

The mass ratio of the alkylenediol (B2) component, the oxytetramethylene glycol unit, and the oxyalkylene glycol unit other than the oxytetramethylene glycol in the polymer (B) is ¹ H-NMR measuring device (specifically, , For example, 500 MHz manufactured by Brunker), and can be obtained by measuring with deuterated chloroform as a solvent.

The number average molecular weight of the polymer (B) is 1000 to 3000. By setting the number average molecular weight to 1000 to 3000, compatibility with the aromatic polycarbonate resin (A) and suppression of mold deposits can be achieved at the same time, and if it is less than 1000, the mold deposits during molding increase to 3000. If it exceeds, the compatibility with the aromatic polycarbonate resin (A) is lowered, the light transmittance is lowered, and the hue improving effect is deteriorated. The number average molecular weight is preferably 1500 or more, more preferably 1800 or more, further preferably 2000 or more, preferably 2800 or less, more preferably 2600 or less, further 2400 or less, and particularly preferably 2200 or less. ..
The number average molecular weight of the polymer (B) referred to here is the number average molecular weight Mn calculated based on the hydroxyl value measured based on JIS K1577.

The content of the polymer (B) is 0.1 to 3 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). With such a content, the hue, heat-resistant discoloration, and non-chargeability are excellent. The preferable content of the polymer (B) is 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, and preferably 2.5 parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). It is less than or equal to parts by mass, more preferably less than 2 parts by mass, and even more preferably less than or equal to 1.8 parts by mass.

[Phosphorus stabilizer (C)]
The polycarbonate resin composition for an optical member of the present invention contains a phosphorus-based stabilizer. By containing a phosphorus-based stabilizer, the hue of the polycarbonate resin composition of the present invention is further improved.
Any known phosphorus-based stabilizer can be used. Specific examples include phosphoric acid, phosphonic acid, phosphite, phosphinic acid, polyphosphoric acid and other phosphorus oxo acids; acidic sodium pyrophosphate, potassium pyrophosphate, acidic calcium pyrophosphate and other acidic pyrophosphate metal salts; phosphoric acid. Phosphates of Group 1 or Group 2B metals such as potassium, sodium phosphate, cesium phosphate, zinc phosphate; phosphate compounds, phosphite compounds, phosphonite compounds and the like can be mentioned, with phosphite compounds being particularly preferred. By selecting the phosphite compound, a polycarbonate resin composition having higher discoloration resistance and continuous productivity can be obtained.

Here, the phosphite compound is a trivalent phosphorus compound represented by the general formula: P (OR) ₃ , and R represents a monovalent or divalent organic group.
Examples of such phosphite compounds include triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl-phenyl) phosphite, and tris (2,4-di-tert-butylphenyl) phos. Fight, monooctyldiphenylphosphite, dioctylmonophenylphosphite, monodecyldiphenylphosphite, didecylmonophenylphosphite, tridecylphosphite, trilaurylphosphite, tristearylphosphite, distearylpentaerythritol diphosphite, Bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite, bis (2,6-di-tert-butylphenyl) octylphosphite, 2,2-methylenebis (4,6-di) -Tert-Butylphenyl) octylphosphite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene-diphosphite, 6- [3- (3-tert-butyl-hydroxy-5-methyl) Phenyl) propoxy] -2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3,2] -dioxaphosfepine and the like.

Among such phosphite compounds, the aromatic phosphite compound represented by the following formula (1) or (2) is more preferable because the heat-resistant discoloration property of the polycarbonate resin composition of the present invention is effectively enhanced. ..

[In the formula (1), R ¹ , R ² and R ³ may be the same or different, respectively, and represent an aryl group having 6 to 30 carbon atoms. ]

[In the formula (2), R ⁴ and R ⁵ may be the same or different, respectively, and represent an aryl group having 6 or more and 30 or less carbon atoms. ]

As the phosphite compound represented by the above formula (1), triphenylphosphine, tris (monononylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite and the like are preferable. Of these, tris (2,4-di-tert-butylphenyl) phosphite is more preferable. Specific examples of such an organic phosphite compound include "ADEKA STAB 1178" manufactured by ADEKA, "Sumilyzer TNP" manufactured by Sumitomo Chemical, "JP-351" manufactured by Johoku Chemical Industry, and "ADEKA STAB" manufactured by ADEKA. 2112 ”,“ Irgaphos 168 ”manufactured by BASF,“ JP-650 ”manufactured by Johoku Chemical Industry Co., Ltd. and the like.

Examples of the phosphite compound represented by the above formula (2) include bis (2,4-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,6-di-tert-). Those having a pentaerythritol diphosphite structure such as butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-dicumylphenyl) pentaerythritol diphosphite are particularly preferable. Specific examples of such an organic phosphite compound are preferably "ADEKA STAB PEP-36" manufactured by ADEKA and "Doverphos S-9228" manufactured by Doverchemical.

The phosphorus-based stabilizer may contain one type, or two or more types may be contained in any combination and ratio.

The content of the phosphorus-based stabilizer (C) is 0.005 to 0.4 parts by mass, preferably 0.007 parts by mass or more, more preferably 0.007 parts by mass or more, based on 100 parts by mass of the aromatic polycarbonate resin (A). 0.008 parts by mass or more, more preferably 0.01 parts by mass or more, preferably 0.3 parts by mass or less, still more preferably 0.2 parts by mass or less, particularly preferably 0.15 parts by mass or less, 0 Most preferably, it is 1 part by mass or less. When the content of the phosphorus-based stabilizer (C) is less than 0.005 parts by mass in the above range, the hue improving effect is insufficient, and the content of the phosphorus-based stabilizer (C) exceeds 0.4 parts by mass. In that case, the heat-resistant discoloration property deteriorates.

[Epoxy compound, oxetane compound (D)]
The resin composition of the present invention preferably further contains an epoxy compound and / or an oxetane compound.

As the epoxy compound, a compound having one or more epoxy groups in one molecule is used. Specifically, phenylglycidyl ether, allylglycidyl ether, t-butylphenylglycidyl ether, 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'-methylsilohexyl Carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene glycol, Bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxidate, 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-epoxycyclohexylcarboxylate, N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl Carboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexylcarboxylate, N-butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexylcarboxylate, octadecyl-3,4-epoxycyclohexylcarboxylate, 2-Epoxyhexyl-3', 4'-epoxycyclohexylcarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3', 4'-epoxycyclohexylcarboxylate, 4,5-epoxy anhydride tetrahydrophthalic acid, 3 -T-butyl-4,5-epoxy anhydride tetrahydrophthalic acid, diethyl4,5-epoxy-cis-1,2-cyclohexyldicarboxy Preferable examples include rates, di-n-butyl-3-t-butyl-4,5-epoxy-cis-1,2-cyclohexyldicarboxylate, epoxidized soybean oil, and epoxidized linseed oil.

Among these, 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 and the like are particularly preferable. ..
The epoxy compounds may be used alone or in combination of two or more.

The content of the epoxy compound is preferably 0.005 to 0.2 parts by mass, more preferably 0.007 parts by mass or more, and more preferably 0.007 parts by mass or more, based on 100 parts by mass of the aromatic polycarbonate resin (A). It is preferably 0.15 parts by mass or less, more preferably 0.1 parts by mass or less, and particularly preferably 0.05 parts by mass or less. If the content of the epoxy compound is less than 0.005 parts by mass, the hue and heat-resistant discoloration tend to be insufficient, and if it exceeds 0.2 parts by mass, not only the heat resistance is deteriorated but also the hue is lowered. , Gas is easily generated during molding.

As the oxetane compound, any compound having one or more oxetane groups in the molecule can be used, and a monooxetane compound having one oxetane group in the molecule and a monooxetane compound having two or more oxetane groups in the molecule can be used. Any bifunctional or higher functional polyoxetane compound can be used.
By containing the oxetane compound, good hue and high heat-resistant discoloration can be further improved.

As the monooxetane compound, compounds represented by the following general formulas (Ia), (Ib) or (II) 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 (Ia), (Ib) and (II), R ¹ is an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, preferably a methyl group or an ethyl group. Particularly preferably, it is an ethyl group.
Further, R ² is an alkyl group or a phenyl group, preferably an alkyl group having 2 to 10 carbon atoms, and may be any of a chain alkyl group, a branched alkyl group and an alicyclic alkyl group. Alternatively, it may be a chain or branched alkyl group having an ether bond (ether-based oxygen atom) in the middle of the alkyl chain. Specific examples of R ² include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl group, nonyl group, decyl group, 3-Okishipenchiru group, a cyclohexyl group, a phenyl The group can be mentioned. Of these, R ² is preferably a ² -ethylhexyl group, a phenyl group, or a cyclohexyl group.

Specific examples of the compound of the general formula (IA) include 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, and 3-hydroxymethyl-. Preferred examples thereof include 3-normal butyl oxetane and 3-hydroxymethyl-3-propyl oxetane. Among them, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane and the like are particularly preferable.
As a specific example of the compound of the general formula (Ib), 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane and the like are particularly preferable.

In the general formula (II), R ³ is a divalent organic group which may have an aromatic ring, and examples thereof include an ethylene group, a propylene group, a butylene group, a neopentylene group and an n-pentamethylene group. , n- hexamethylene group, typically a straight or branched alkylene group having 1 to 12 carbon atoms, a phenylene group, the ^formula: -CH ² -Ph-CH 2 - or ^{-CH 2 -Ph-Ph-CH 2} - (Here, Ph indicates a phenyl group), a divalent group, a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol Z residue, a cyclohexanedimethanol residue, and a tricyclode. Candimethanol residues and the like can be mentioned.

Specific examples of the compound of the general formula (II) include bis (3-methyl-3-oxetanylmethyl) ether, bis (3-ethyl-3-oxetanylmethyl) ether, and 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-3-3) Il) methoxy] methyl} oxetane, 4,4'-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, 1,4-bis [(3-ethyl-3-oxetanyl) methoxymethyl] benzene, etc. It can be mentioned particularly preferably.

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

The content of the oxetane compound is preferably 0.005 to 0.2 parts by mass, more preferably 0.007 parts by mass or more, and particularly preferably 0. parts by mass with respect to 100 parts by mass of the aromatic polycarbonate resin (A). It is 01 parts by mass or more, more preferably 0.15 parts by mass or less, further preferably 0.1 parts by mass or less, and particularly preferably 0.05 parts by mass or less. If the content of the oxetane compound is less than 0.005 parts by mass, the hue and heat-resistant discoloration tend to be insufficient, and if it exceeds 0.2 parts by mass, the heat-resistant discoloration tends to deteriorate, and during molding. Gas is likely to be generated.

The epoxy compound and the oxetane compound are preferably contained together, and the total content in that case is 0.005 to 0.2 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). Is preferable.

[Additives, etc.]
The polycarbonate resin composition of the present invention has other additives other than those described above, such as antioxidants, mold release agents, ultraviolet absorbers, fluorescent whitening agents, pigments, dyes, polymers other than polycarbonate resins, and difficulties. It can contain additives such as a fuel agent, an impact resistance improver, an antistatic agent, a plasticizer, and a compatibilizer. These additives may be used alone or in combination of two or more.

Examples of resins other than the polycarbonate resin include thermoplastic polyester resins such as acrylic resins having an aromatic ring structure, polyethylene terephthalate resins, polytrimethylene terephthalates, and polybutylene terephthalate resins; polystyrene resins and high impact polystyrene resins (HIPS). , Acrylonitrile-styrene copolymer (AS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin) and other styrene resins; polyamide resin; Examples thereof include polyimide resin; polyetherimide resin; polyphenylene ether resin; polyphenylene sulfide resin; and polysulfone resin.

As the other resin, one type may be contained, or two or more types may be contained in any combination and ratio. However, when the other resin is contained, the content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and further 5 parts by mass or less, particularly, with respect to 100 parts by mass of the polycarbonate resin (A). It is preferably 3 parts by mass or less, particularly 1 part by mass or less.

[Manufacturing method of polycarbonate resin composition]
The method for producing the polycarbonate resin composition of the present invention is not limited, and a known method for producing the polycarbonate resin composition can be widely adopted, and the aromatic polycarbonate resin (A), the polymer (B) and the phosphorus-based stabilizer (C) can be widely adopted. , And other ingredients to be blended as needed are premixed using various mixers such as tumblers and henschel mixers, and then Banbury mixers, rolls, brabenders, single-screw kneading extruders, and twin-screw kneading extruders. Examples thereof include a method of melt-kneading with a mixer such as a machine or a kneader. The temperature of melt-kneading is not particularly limited, but is usually in the range of 240 to 320 ° C.

[Optical member]
The polycarbonate resin composition for an optical member of the present invention can manufacture an optical member by molding pellets obtained by pelletizing the above-mentioned polycarbonate resin composition by various molding methods. Further, the resin melt-kneaded by an extruder can be directly molded into an optical member without passing through pellets.

The polycarbonate resin composition of the present invention has excellent compatibility, has a good hue even at a high processing temperature, has excellent antistatic properties, and generates extremely little gas during molding. Therefore, particularly by an injection molding method. , Suitable for molding optical members.
The resin temperature during injection molding is determined by the size and thickness of the target molded product and the injection capacity of the molding machine. In the molding of the polycarbonate resin composition of the present invention, it is usually used in the range of 280 ° C. to 390 ° C., preferably 280 ° C. to 360 ° C., but it should be molded at a low temperature as long as the state of filling property and molding strain allows. Is desirable. When a conventional polycarbonate resin composition is used, there is a problem that yellowing of the molded product is likely to occur when the resin temperature during molding is raised. However, by using the resin composition of the present invention, Even in the above temperature range, it is possible to manufacture a molded product having a good hue, particularly an optical member.
The resin temperature is grasped as the barrel set temperature when it is difficult to measure it directly.

Examples of the optical member include parts of devices / appliances that directly or indirectly use a light source such as an LED, an organic EL, an incandescent lamp, a fluorescent lamp, and a cathode tube, and include a light guide plate, a surface light emitting body member, and a lighting member. Is exemplified as a typical example, and is particularly suitable for an optical component having a long optical path length of 50 mm or more.

The light guide plate is for guiding the light of a light source such as an LED in a liquid crystal backlight unit, various display devices, and a lighting device, and the light input from the side surface or the back surface is usually provided on the front surface. It diffuses due to the unevenness and emits uniform light. Its shape is usually flat, and the surface may or may not have irregularities.
Molding of the light guide plate is usually preferably performed by an injection molding method, an ultra-high speed injection molding method, an injection compression molding method or the like.

The light guide plate using the polycarbonate resin composition of the present invention can be suitably used in the fields of liquid crystal backlight units, various display devices, and lighting devices. Examples of such devices include various mobile terminals such as mobile phones, mobile notebooks, netbooks, slate PCs, tablet PCs, smartphones, tablet terminals, cameras, watches, notebook computers, various displays, lighting devices, and the like. In particular, it can be suitably used when the optical path length is as long as 50 mm or more.

Further, as the optical member, a light guide member for external lighting, for example, a light guide for guiding light from a light source such as an LED in a headlight (headlamp) for a vehicle such as an automobile or a motorcycle, a rear lamp, a fog lamp, or the like. A lens or the like is also suitable, and can be suitably used particularly when the optical path length is as long as 50 mm or more.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not construed as being limited to the following examples.
The raw materials used in the following examples and comparative examples are as shown in Table 1 below.
In Table 1, "PTMG" is polyoxytetramethylene glycol, "PPG" is poly (2-methyl) ethylene glycol, "PEG" is polyethylene glycol, "EG" is ethylene glycol, "DEG" is diethylene glycol, and "BPA". Is an abbreviation for bisphenol A.

(Examples 1 to 31, Comparative Examples 1 to 5)
[Manufacturing of resin composition pellets]
Each of the above components is blended in the proportions (parts by mass) shown in Tables 2 to 5 below, mixed in a tumbler for 20 minutes, and then a single-screw extruder with a vent having a screw diameter of 40 mm (manufactured by Tanabe Plastic Machinery Co., Ltd.). VS-40 "), melt-kneaded at a cylinder temperature of 250 ° C. and 100 rpm, put the discharged strands into a pelletizer, and strand-cut to obtain pellets.

[Evaluation of hue (YI)]
The pellets obtained above are dried at 120 ° C. for 5 to 7 hours with a hot air circulation type dryer, and then subjected to an injection molding machine (“HSP100A” manufactured by Sodick Co., Ltd.) at a resin temperature of 340 ° C. and a mold temperature of 80 ° C. A long light path molded product (300 mm × 7 mm × 4 mm) was formed in a cycle of 40 seconds.
For this long optical path molded product, YI (yellowing degree, based on ASTM D1925) was measured with an optical path length of 300 mm. A long optical path spectroscopic transmission chromometer (“ASA 1” manufactured by Nippon Denshoku Kogyo Co., Ltd., C light source, 2 ° field of view) was used for the measurement.

[Evaluation of heat-resistant discoloration (△ YI)]
The YI value after holding the long optical path molded product obtained above in an oven at 95 ° C. for 500 hours is measured in the same manner as in the above method, and the amount of change (ΔYI) from the YI value before temperature treatment is determined. Therefore, the heat-resistant discoloration property was evaluated. The smaller the ΔYI, the better the heat-resistant discoloration.
The above evaluation results are shown in Tables 2 to 5 below.

Since the polycarbonate resin composition of the present invention is excellent in thermal stability, heat-resistant discoloration and antistatic properties (antistatic properties), it can be extremely suitably used for various optical members, and its industrial utility is very high.

Claims (12)

1. 0.1 to 3 parts by mass of the polyoxytetramethylene glycol-based multi-component polymer (B) and 0.005 to 0.4 parts by mass of the phosphorus-based stabilizer (C) with respect to 100 parts by mass of the aromatic polycarbonate resin (A). Part-containing resin composition
   A polyoxytetramethylene glycol-based multi-component polymer (B) is a multi-component polymer having a structure in which polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are bonded via an alkylene diol (B2). A polycarbonate resin composition for an optical member, which has a number average molecular weight (Mn) of 1000 to 3000.
2. The polycarbonate resin composition for an optical member according to claim 1, wherein the alkylene diol (B2) is the diol component having the lowest content among all the diol components constituting the polyoxytetramethylene glycol-based multiplex polymer (B).
3. The polyoxytetramethylene glycol-based multi-element polymer (B) contains 10 mol% or less of units derived from the alkylene diol (B2) in all the diol components constituting the multi-element polymer (B), and oxytetra. The polycarbonate resin composition for an optical member according to claim 1 or 2, wherein the mass ratio of the content of the unit derived from methylene glycol is 55 to 80% by mass.
4. The optical member according to any one of claims 1 to 3, wherein the alkylene diol (B2) is an alkylene diol monomer in which the main chain may be branched with 2 to 6 carbon atoms, or a dimer thereof. Polycarbonate resin composition for.
5. Any of claims 1 to 4, wherein the alkylene diol (B2) is ethylene glycol, 2- (methyl) ethylene glycol, (2-ethyl) ethylene glycol, trimethylene glycol, neopentyl glycol, or a dimer thereof. The polycarbonate resin composition for an optical member according to.
6. Claim that the polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are random copolymers containing an oxytetramethylene glycol unit and an oxyalkylene glycol unit other than the oxytetramethylene glycol unit. The polycarbonate resin composition for an optical member according to any one of 1 to 5.
7. The oxyalkylene glycol units other than the oxytetramethylene glycol unit in the polyoxytetramethylene glycol-based random polymer component (B1) and (B3) are ethylene glycol, (2-methyl) ethylene glycol, trimethylene glycol, and (2). -Ethylene) The polycarbonate resin composition for an optical member according to any one of claims 1 to 6, which is selected from units derived from ethylene glycol.
8. Polyoxytetramethylene glycol-based random polymer components (B1) and (B3) are copolymers containing oxytetramethylene glycol units and oxy (2-methyl) ethylene glycol units, and alkylenediol (B2) is ethylene. The polycarbonate resin composition for an optical member according to any one of claims 1 to 7, which is glycol or diethylene glycol.
9. The optical according to any one of claims 1 to 8, further containing 0.005 to 0.2 parts by mass of the epoxy compound and / or the oxetane compound (D) with respect to 100 parts by mass of the aromatic polycarbonate resin (A). Polycarbonate resin composition for members.
10. A molded product for an optical member comprising the polycarbonate resin composition according to any one of claims 1 to 9.
11. The molded product according to claim 10, wherein the molded product is a light guide for automobile lighting, a light guide for lighting, or a light guide plate for a backlight, which has an optical path length of 50 mm or more.
12. A polyoxytetramethylene glycol-based multipolymer (B) obtained by addition polymerization of tetrahydrofuran and other alkylene oxides with alkylenediol (B2) as an initiator with respect to 100 parts by mass of the aromatic polycarbonate resin (A). A method for producing a polycarbonate resin composition for an optical member, which comprises blending 0.1 to 3 parts by mass and 0.005 to 0.4 parts by mass of a phosphorus-based stabilizer (C).