WO2020110431A1

WO2020110431A1 - Polycarbonate resin composition for optical member

Info

Publication number: WO2020110431A1
Application number: PCT/JP2019/036282
Authority: WO
Inventors: 黒川　晴彦
Original assignee: 三菱エンジニアリングプラスチックス株式会社
Priority date: 2018-11-29
Filing date: 2019-09-17
Publication date: 2020-06-04
Also published as: CN113166530A; JPWO2020110431A1; JP6719857B1; CN113166530B

Abstract

Provided is a polycarbonate resin composition which is for an optical member, has excellent compatibility and a good color, and generates very little gas during molding. This polycarbonate resin composition for an optical member is characterized by containing, with respect to 100 parts by mass of an aromatic polycarbonate resin (A): 0.1-3 parts by mass of a compound (B) in which a polyoxytetramethylene glycol-based polymer (B1) is bonded with an alicyclic diol (B2); and 0.005-0.4 parts by mass of a phosphorus stabilizer (C), wherein the compound (B) has 20 mass% or less of the alicyclic diol (B2) component, and the mass ratio of an oxytetramethylene glycol unit in a component excluding the alicyclic diol (B2) component is 55-80 mass%, and the number average molecular weight of the component (B) is 1000-2400.

Description

Polycarbonate resin composition for optical members

The present invention relates to a polycarbonate resin composition for optical members, and more particularly, to a polycarbonate resin composition for optical members which has excellent compatibility, has a good hue, and generates very little gas during molding.

Polycarbonate resin has excellent transparency, mechanical properties, thermal properties, electrical properties and weather resistance, and is used for optical members such as light guide plates. However, since the light transmittance of the polycarbonate resin is lower than that of polymethylmethacrylate or the like, there is a problem that the planar light source device or the like using the light guide plate of the polycarbonate resin has low brightness. Therefore, it is required to improve the brightness and light transmittance of a polycarbonate resin light guide plate or the like.

Patent Document 1 provides a polycarbonate resin composition for a light guide plate, which does not impair the original properties of the aromatic polycarbonate resin, has no white turbidity or decrease in transmittance, and has good transmittance and hue. For the purpose, an aromatic polycarbonate resin composition for a light guide plate is disclosed, which comprises 0.01 to 1 part by weight of a polyalkylene glycol in an aromatic polycarbonate resin.

However, polyalkylene glycol does not necessarily have sufficient compatibility with the polycarbonate resin, so that the obtained light guide plate is liable to have cloudiness, transparency is likely to be deteriorated, and hue is also likely to be deteriorated.

In particular, in various liquid crystal display devices, thinning and large-sized thinning are progressing at a remarkable speed, and an edge type in which light is incident on a light guide plate from a direct type to a side edge has come to be adopted, Optical members such as the light guide plate are required to have higher transparency and hue. This requirement becomes more severe 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.

Also, when molding a polycarbonate resin composition for optical members, the occurrence of deposits on the mold is a major problem. Especially when molding a high performance light guide member, frequent maintenance of the mold is required.

JP, 2004-051700, A

The present invention has been made in view of the above circumstances, and its object (problem) is to have excellent compatibility, have a good hue, and gas generation during molding without impairing the original properties of the polycarbonate resin. The object is to provide a polycarbonate resin composition for optical members having a very small amount.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to achieve the said subject, this inventor is a compound which couple|bonded the polyoxytetramethylene glycol type|system|group with alicyclic diol, Comprising: Alicyclic diol and oxytetramethylene glycol unit The inventors have found that the above-mentioned problems can be solved by blending a compound having a specific number average molecular weight within a specific range, and have completed the present invention.
The present invention relates to the following polycarbonate resin composition for optical members and molded articles.

[1] 0.1 to 3 parts by mass of the compound (B) obtained by binding the polyoxytetramethylene glycol polymer (B1) with the alicyclic diol (B2) to 100 parts by mass of the aromatic polycarbonate resin (A). And 0.005 to 0.4 parts by mass of a phosphorus-based stabilizer (C),
In the compound (B), the alicyclic diol (B2) component is 20 mass% or less, and the mass ratio of the oxytetramethylene glycol unit in the component excluding the alicyclic diol (B2) component is 55 to 80 mass. %, and the compound (B) has a number average molecular weight of 1000 to 2400, a polycarbonate resin composition for optical members.
[2] The optical member according to the above [1], wherein the polyoxytetramethylene glycol-based polymer (B1) is a copolymer containing an oxytetramethylene glycol unit and an oxyalkylene glycol unit other than oxytetramethylene glycol. Polycarbonate resin composition for use.
[3] Further, in the above [1] or [2], further containing 0.005 to 0.2 parts by mass of the epoxy compound and/or the oxetane compound (D) per 100 parts by mass of the aromatic polycarbonate resin (A). A polycarbonate resin composition for an optical member as described above.
[4] The polycarbonate resin composition for optical members according to any one of the above [1] to [3], wherein the alicyclic diol (B2) is hydrogenated bisphenol A.
[5] A molded article for an optical member, comprising the polycarbonate resin composition according to any one of [1] to [3] above.
[6] The molded product according to the above [5], wherein the molded product is a light guide for automobile lighting, a light guide for illumination, or a light guide plate for a backlight, in which the optical path length of the optical component is 50 mm or more.

The polycarbonate resin composition of the present invention does not impair the original properties of the polycarbonate resin, has excellent compatibility, has a good hue, and has very little gas generation during molding, and there is no problem of mold contamination, and various Can be suitably used for the optical member.

It is a top view of the drop type mold used for evaluation of mold pollution in an example.

Hereinafter, the present invention will be described in detail with reference to exemplary embodiments and examples.
In addition, in the present specification, unless otherwise specified, the term “to” is used to mean that the numerical values before and after that are included as the lower limit value and the upper limit value.

The polycarbonate resin composition for optical members of the present invention is a compound (B in which 100 parts by mass of an aromatic polycarbonate resin (A) is bound to a polyoxytetramethylene glycol polymer (B1) with an alicyclic diol (B2). 0.1 to 3 parts by mass and 0.005 to 0.4 parts by mass of the phosphorus-based stabilizer (C),
In the compound (B), the alicyclic diol (B2) component is 20 mass% or less, and the mass ratio of the oxytetramethylene glycol unit in the component excluding the alicyclic diol (B2) component is 55 to 80 mass. %, and the number average molecular weight of the compound (B) is 1000 to 2400.
Hereinafter, the present invention will be described in detail.

[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 phosgene or a carbonic acid diester. The aromatic polycarbonate polymer may have a branch. The method for producing the aromatic polycarbonate resin is not particularly limited and may be a conventional method such as a phosgene method (interfacial polymerization method) or a melting method (transesterification method).

Typical aromatic dihydroxy compounds include, for example, 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 Etc.

Among the above aromatic dihydroxy compounds, 2,2-bis(4-hydroxyphenyl)propane (that is, bisphenol A) is particularly preferable.
Moreover, the said aromatic dihydroxy compound may be used individually by 1 type, or may be used in mixture of 2 or more types.

When producing the aromatic polycarbonate resin (A), a small amount of a 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 a branch.
Examples of the polyhydric phenol having 3 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 (ie, isatin bisphenol), 5-chlorisatin, 5,7- Examples thereof include dichlorisatin, 5-bromoisatin and the like. Among these, 1,1,1-tris(4-hydroxyphenyl)ethane and 1,3,5-tris(4-hydroxyphenyl)benzene are 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 the transesterification polymerization, carbonic acid diester is used as a monomer instead of phosgene. Representative 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 may be used alone or in combination of two or more. Among these, diphenyl carbonate and substituted diphenyl carbonate are preferable.

The carbonic acid diester may 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. Representative dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate and diphenyl isophthalate. When a part of the carbonic acid diester is replaced with such a dicarboxylic acid or dicarboxylic acid ester, polyester carbonate is obtained.

A catalyst is usually used when producing an aromatic polycarbonate resin by the transesterification method. The catalyst species 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, 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 deactivate the catalyst with 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.
In a light guide plate such as a backlight for 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. 2,000 or more, more preferably 14,500 or less.
Further, in a light guide or lens for guiding light from a light source such as an LED in a headlight for vehicles such as automobiles and motorcycles or a rear lamp, 15,000 to 23,000 is preferable, and fluidity From the viewpoint of hue, it is more preferably 17,000 to 20,000.
Further, in a light guide for illumination or the like, it is preferably 15,000 to 24,000, 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 or more of the above range, 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 polycarbonate resin composition of the invention can be suppressed and improved in fluidity, the molding processability can be improved, and the molding process can be easily performed.
Two or more kinds of aromatic polycarbonate resins having different viscosity average molecular weights may be mixed and used, and in this case, polycarbonate resins having a viscosity average molecular weight outside the above-mentioned preferable range may be mixed.

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

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

Note that 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 a colorimetric determination by the titanium tetrachloride/acetic acid method (method described in Macromol. Chem. 88 215 (1965)).

The aromatic polycarbonate resin is a polycarbonate resin alone (the polycarbonate resin alone is not limited to an embodiment including only one kind of the polycarbonate resin, and includes, for example, an embodiment including a plurality of kinds of polycarbonate resins having different monomer compositions and molecular weights). It is also possible to use in combination with an alloy (mixture) of a polycarbonate resin and another thermoplastic resin. Further, for example, for the purpose of further improving flame retardancy and impact resistance, a polycarbonate resin is a copolymer with an oligomer or polymer having a siloxane structure; a phosphorus atom for the purpose of further improving thermal oxidation stability and flame retardancy. Copolymer with a monomer, oligomer or polymer having: a copolymer with a monomer, oligomer or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermo-oxidative stability; polystyrene for improving optical properties A copolymer mainly composed of a polycarbonate resin, such as a copolymer with an oligomer or polymer having an olefinic structure; a copolymer with a polyester resin oligomer or polymer for the purpose of improving chemical resistance; Good.

Also, 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 higher, preferably 2000 or higher, and is usually 9500 or lower, preferably 9000 or lower. Furthermore, it is preferable that the content of the polycarbonate ligomer is 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 recycled polycarbonate resin is preferably 80% by mass or less, and more preferably 50% by mass or less, of the aromatic polycarbonate resin. Recycled polycarbonate resin is likely to have undergone deterioration such as heat deterioration and aging deterioration, so if such polycarbonate resin is used in excess of the above range, it is possible to reduce hue and mechanical properties. This is because there is nature.

[Compound (B) in which polyoxytetramethylene glycol polymer (B1) is bound by alicyclic diol (B2)]
The polycarbonate resin composition for optical members of the present invention contains a compound (B) obtained by binding a polyoxytetramethylene glycol polymer (B1) with an alicyclic diol (B2).

The compound (B) is preferably represented by the following formula (1).
Y-XY' (1)
In the above formula (1), X is a residue obtained by removing a hydroxyl group from the alicyclic diol (B2), Y and Y′ are components derived from the polyoxytetramethylene glycol polymer (B1), and are the same. But it can be different.

As the alicyclic diol (B2), an alicyclic diol compound having preferably 4 to 30 carbon atoms, more preferably 6 to 20 carbon atoms is used.
Specific examples of the alicyclic diol (B2) include cyclobutanediols such as 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,4-cyclohexanediol, and 1,2-cyclohexanediol. Cyclohexanediols such as 1,3-cyclohexanediol and 2-methyl-1,4-cyclohexanediol, cyclohexane such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol and 1,4-cyclohexanedimethanol Dimethanols, 2,2-bis(4-hydroxycyclohexyl)propane (ie hydrogenated bisphenol A), 2,3-norbornanedimethanol, 2,5-norbornanedimethanol and other norbornanedimethanols, tricyclode Candimethanol, pentacyclopentadecanedimethanol, 1,3-adamantanediol, 2,2-adamantanediol, decalindimethanol, 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8 , 10-tetraoxaspiro[5.5]undecane (that is, spiroglycol) and the like. These may be stereoisomers, and there is no limitation on cis and trans.

Among the above, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, the cyclohexanediols, the cyclohexanedimethanols, 2,2-bis(4-hydroxycyclohexyl)propane (that is, hydrogen Bisphenol A) is more preferable, and 2,2-bis(4-hydroxycyclohexyl)propane (that is, hydrogenated bisphenol A) is particularly preferable.

The alicyclic diol (B2) may be used alone or in combination of two or more. Further, as the alicyclic diol (B2), a small amount of an aliphatic diol compound or an aromatic diol may be used in combination as long as the effects of the present invention are not impaired.

The polyoxytetramethylene glycol polymer (B1) is a polymer having a tetramethylene ether unit [—CH ₂ CH ₂ CH ₂ CH ₂ —O—]. The polyoxytetramethylene glycol polymer (B1) is preferably a copolymer having other alkylene ether units in addition to the tetramethylene ether units.

The other alkylene ether units may be linear or branched alkylene ether units. The alkylene ether unit has preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, further preferably 2 to 12 carbon atoms, and particularly preferably 2 to 10 carbon atoms.

As an example of the linear alkylene ether unit, ethylene glycol, trimethylene glycol, pentamethylene glycol, and hexamethylene glycol are preferably mentioned as the alkylene glycol. These may be one kind or two kinds. It may be a mixture of the above.
Among the above, ethylene glycol and trimethylene glycol are more preferable.

Examples of the branched alkylene ether unit include (2-methyl)ethylene glycol, (2-ethyl)ethylene glycol, (2-methyl)trimethylene glycol, and (3-methyl)triethylene glycol, as an alkylene glycol. Methylene 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), 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, Examples include (5,5-diethyl)pentamethylene glycol. However, these may be mixed. Are preferred.
These may be used alone or as a mixture of two or more.
Of the above, more preferred are (2-methyl)ethylene glycol, (2,2-diethyl)trimethylene glycol (ie neopentyl glycol) and (3-methyl)tetramethylene glycol.

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

The polyoxytetramethylene glycol-based polymer (B1) is an oxytetramethylene glycol unit and ethylene glycol other than oxytetramethylene glycol, (2-methyl)ethylene glycol, trimethylene glycol, neopentyl glycol, (2-methyl). A copolymer composed of tetramethylene glycol is more preferable.

The polyoxytetramethylene glycol-based polymer (B1) may be a random copolymer or a block copolymer, but the fact that it is a random copolymer suppresses crystallization of polyalkylene glycol. Compatibility with the group-polycarbonate resin (A) and handleability are improved. Further, the compound (B) obtained by binding this with an alicyclic diol (B2) further improves the compatibility with the polycarbonate resin.

As the compound (B), a glycol having the above-mentioned alkylene ether unit, an alkylene oxide thereof, or a polyether-forming derivative in the presence of the alicyclic diol (B2) is described, for example, in JP-A-2018-184557. In the known method, the 1,4-butanediol component before the initiation of the polymerization is replaced with the alicyclic diol (B2) component and the polymerization is performed under appropriate reaction conditions. The polyoxytetramethylene glycol polymer (B1) portion of the compound (B) may be a block copolymer or a random copolymer, but a random copolymer is preferable.

In the compound (B), the alicyclic diol (B2) component is 20 mass% or less, and the mass ratio of the oxytetramethylene glycol unit in the component excluding the alicyclic diol (B2) component is 55 to 80 mass. %.
When the content of the alicyclic diol (B2) component is 20% by mass or less, the thermal stability of the compound (B) becomes good, and when it exceeds 20% by mass, the molecular chain length becomes short and the heat of the compound (B) decreases. Stability deteriorates and a large amount of mold deposits occur. The amount of the alicyclic diol (B2) component is preferably 18% by mass or less, more preferably 15% by mass or less, preferably 3% by mass or more, more preferably 4% by mass or more, further preferably 5% by mass. It is at least mass%, particularly preferably at least 6 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, the aromatic compound The compatibility with the polycarbonate resin (A) becomes poor. 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, further preferably 65% by mass. % Or less, particularly preferably 63% by mass or less.
The mass ratio of the units other than oxytetramethylene glycol in the components excluding the alicyclic diol (B2) component is preferably 20 to 47 mass%, more preferably 30 mass% or more, and preferably Is 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 alicyclic diol (B2) component, the oxytetramethylene glycol unit and the oxytetramethylene glycol unit was determined by using a ¹ H-NMR measuring device (specifically, 500 MHz manufactured by Brunker) and deuterated. It can be determined by measuring with chloroform as a solvent.

The number average molecular weight of the compound (B) is 1,000 to 2,400. By adjusting the number average molecular weight to 1000 to 2400, compatibility with the aromatic polycarbonate resin (A) and suppression of mold deposit can be achieved, and when it is less than 1000, mold deposit during molding increases and 2400 When it exceeds, the compatibility with the aromatic polycarbonate resin (A) decreases and the hue improving effect deteriorates. The number average molecular weight is preferably 1500 or more, more preferably 1800 or more, further preferably 2000 or more, preferably 2300 or less, more preferably 2200 or less.
The number average molecular weight of the compound (B) here is the number average molecular weight Mn calculated based on the hydroxyl value measured according to JIS K1577.

The content of the compound (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 and transparency are excellent. The preferable content of the compound (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). Parts or less, more preferably 2 parts by mass or less, still more preferably 1.8 parts by mass or less.

[Phosphorus stabilizer (C)]
The polycarbonate resin composition for optical members of the present invention contains a phosphorus-based stabilizer. By containing the phosphorus-based stabilizer, the hue of the polycarbonate resin composition of the present invention is further improved.
Any known phosphorous stabilizer can be used. Specific examples thereof include phosphorous oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphate salts such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphoric acid Examples thereof include phosphates of Group 1 or Group 2B metals such as potassium, sodium phosphate, cesium phosphate, and zinc phosphate; phosphate compounds, phosphite compounds, phosphonite compounds, and the like, and phosphite compounds are particularly preferable. By selecting a 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/dinonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite. Fight, monooctyl diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, Bis(2,4-di-tert-butyl-4-methylphenyl)pentaerythritol phosphite, bis(2,6-di-tert-butylphenyl)octyl phosphite, 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]-dioxaphosphepine and the like.

Among such phosphite compounds, an aromatic phosphite compound represented by the following formula (2) or (3) is more preferable because the thermochromic resistance of the polycarbonate resin composition of the present invention is effectively increased. ..

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

[In the formula (3), R ⁴ and R ⁵ may be the same or different and each represents an aryl group having 6 to 30 carbon atoms. ]

The phosphite compound represented by the above formula (2) is preferably triphenylphosphite, tris(monononylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, 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, "SUMIZER TNP" manufactured by Sumitomo Chemical Co., Ltd., "JP-351" manufactured by Johoku Chemical Industry Co., Ltd., and "ADEKA STAB manufactured by ADEKA". 2112”, “IRGAFOSS 168” manufactured by BASF, and “JP-650” manufactured by Johoku Chemical Industry Co., Ltd., and the like.

Examples of the phosphite compound represented by the above formula (3) 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. As such an organic phosphite compound, specifically, “ADEKA STAB PEP-36” manufactured by ADEKA, “Doverphos S-9228” manufactured by Doverchemical, etc. are preferably exemplified.

The phosphorus-based stabilizer may be contained in one kind, or may be contained in two or more kinds 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 100 parts by mass with respect to 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, more preferably 0.2 parts by mass or less, particularly preferably 0.15 parts by mass or less, 0 Most preferably, it is not more than 1 part by mass. When the content of the phosphorus-based stabilizer (C) is less than 0.005 parts by mass in the above range, the hue and heat discoloration resistance are insufficient, and the content of the phosphorus-based stabilizer (C) is 0.4 parts by mass. If it exceeds, not only the heat discoloration resistance deteriorates but also the wet heat stability decreases.

[Epoxy compound, oxetane compound (D)]
The resin composition of the present invention preferably 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, 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'-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'-methylsirohexyl Carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene glycol, Bis-epoxy cyclohexyl 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-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-ethylhexyl-3',4'-epoxycyclohexylcarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3',4'-epoxycyclohexylcarboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3 -T-Butyl-4,5-epoxy tetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyldicarboxy Preferable examples thereof include rate, 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 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. When the content of the epoxy compound is less than 0.005 parts by mass, the hue and the heat discoloration resistance tend to be insufficient, and when it exceeds 0.2 parts by mass, the heat discoloration property is rather deteriorated and the hue Deterioration and easy generation of gas during molding.

As the oxetane compound, any compound having at least one oxetane group in the molecule can be used, and a monooxetane compound having one oxetane group in the molecule and two or more oxetane groups in the molecule Any of the bifunctional or higher polyoxetane compounds can be used.
By containing the oxetane compound, a good hue and a high degree of heat discoloration resistance can be further improved.

As the monooxetane compound, compounds represented by the following general formula (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 preferred is an ethyl group.
R ² is an alkyl group or a phenyl group, preferably an alkyl group having 2 to 10 carbon atoms, and may be a chain alkyl group, a branched alkyl group or 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 group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, 3-oxypentyl group, cyclohexyl group, phenyl group. A group etc. can be mentioned. Among them, 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, 3-hydroxymethyl- Preferable examples 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 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. , A 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 — (Wherein Ph represents a phenyl group), a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol Z residue, a cyclohexanedimethanol residue, a tricyclode A candimethanol residue etc. can be mentioned.

Specific examples of the compound of general formula (II) 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, etc. It can be mentioned particularly preferably.

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

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 0.01 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). And more preferably 0.15 parts by mass or less, further preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less. When the content of the oxetane compound is less than 0.005 parts by mass, the hue and heat discoloration resistance tend to be insufficient, and when it exceeds 0.2 parts by mass, the heat discoloration resistance tends to be rather deteriorated. Easy to generate gas.

It is preferable that the epoxy compound and the oxetane compound are 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 preferred.

[Additives, etc.]
Polycarbonate resin composition of the present invention, other additives other than the above, for example, antioxidants, mold release agents, ultraviolet absorbers, optical brighteners, pigments, dyes, polymers other than polycarbonate resin, difficult. Additives such as flame retardants, impact modifiers, antistatic agents, plasticizers and compatibilizers may be included. These additives may be used alone or in combination of two or more.

Examples of the resin other than the polycarbonate resin include thermoplastic polyester resins such as acrylic resin having an aromatic ring structure, polyethylene terephthalate resin, polytrimethylene terephthalate, polybutylene terephthalate resin; polystyrene resin, high impact polystyrene resin (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 resins; Polyimide resin; polyetherimide resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin and the like.
The other resins may be contained in one kind or may be contained in two or more kinds in any combination and ratio. However, the content in the case of containing the other resin is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and further 5 parts by mass or less, with respect to 100 parts by mass of the polycarbonate resin (A). It is preferably 3 parts by mass or less, and particularly preferably 1 part by mass or less.

[Method for producing polycarbonate resin composition]
The method for producing the polycarbonate resin composition of the present invention is not limited, and any known method for producing a polycarbonate resin composition can be widely adopted. The aromatic polycarbonate resin (A), the compound (B) and the phosphorus-based stabilizer (C), In addition, other components that are blended as necessary are pre-mixed by using various mixers such as a tumbler and a Henschel mixer, and then Banbury mixer, roll, Brabender, single-screw kneading extruder, twin-screw kneading extruder. A method of melt-kneading with a mixer such as a kneader may be used. 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 optical members of the present invention can be manufactured into an optical member by molding pellets obtained by pelletizing the above polycarbonate resin composition by various molding methods. Alternatively, the resin melt-kneaded by an extruder may be directly molded into an optical member without passing through the pellet.

The polycarbonate resin composition of the present invention is excellent in compatibility, has a good hue even at a high processing temperature, and generates very little gas during molding. Therefore, an optical member is molded by an injection molding method. It is preferably used for.
The resin temperature at the time of 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 molding should be performed at a low temperature as long as the filling property and the molding strain state permit. Is desirable. When using a conventional polycarbonate resin composition, if the resin temperature during molding is increased, there is also a problem that yellowing of the molded product is likely to occur, but by using the resin composition of the present invention, Even within the above temperature range, it becomes possible to manufacture a molded product having a good hue, particularly an optical member.
The resin temperature is understood as the barrel set temperature when it is difficult to directly measure it.

Examples of the optical member include parts of devices and appliances that directly or indirectly utilize light sources such as LEDs, organic ELs, incandescent lamps, fluorescent lamps, and cathode tubes. Light guide plates, surface light emitter members, lighting members, etc. Is exemplified as a typical one, 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 light from a light source such as an LED in a liquid crystal backlight unit, various display devices, and illuminating devices, and light provided from the side surface or the back surface is usually provided on the front surface. Diffuses due to the unevenness, and emits uniform light. The shape is usually a flat plate shape, 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 mobile phones, mobile notebooks, netbooks, slate PCs, tablet PCs, smartphones, various mobile terminals such as tablet terminals, cameras, watches, notebook computers, various displays, and lighting devices. In particular, it can be suitably used even when the optical path length is as long as 50 mm or more.

Further, as the optical member, a light guide member for exterior lighting, such as a vehicle headlight for automobiles or motorcycles, a rear lamp, a fog lamp, or a light guide for guiding light from a light source such as an LED, A lens or the like is also suitable, and especially when the optical path length is as long as 50 mm or more, it can be preferably used.

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

(Examples 1 to 43, Comparative Examples 1 to 8)
[Production of resin composition pellets]
The above components were mixed in the proportions (parts by mass) shown in Table 2 below and mixed for 20 minutes with a tumbler, and then a single screw extruder with a vent having a screw diameter of 40 mm ("VS by Tanabe Plastic Machinery Co., Ltd."-40") was melt-kneaded at a cylinder temperature of 250°C and 100 rpm, and the discharged strand was put into a pelletizer and strand-cut to obtain pellets.

[Compatibility evaluation]
Before the strand discharged from the extruder in the pellet manufacturing process is put into the pelletizer, the resin flowing out from the extruder die is allowed to flow down to the floor for about 1 minute, and the thickness is about 18 mm, the diameter is 150 to 180 mm, and the weight is about 350±20 g. After obtaining a disc-shaped mass, it was cooled at room temperature. The transparency of the disc-shaped resin block was visually evaluated according to the following four grades.
A: Excellent transparency B: Excellent transparency C: Slight turbidity D: Large turbidity The resin lumps are turbid due to poor compatibility with the blended component (B) and other polyalkylene glycols and homogeneity. It means that mixing is not possible.

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

[Evaluation of mold contamination (mold deposit)]
After drying the pellets obtained above at 120° C. for 5 hours, an injection molding machine (“SE-7M/C12” manufactured by Sumitomo Heavy Industries, Ltd.) was used to obtain a drop mold as shown in FIG. Using a cylinder temperature of 340° C., a molding cycle of 10 seconds, and a mold temperature of 40° C., 100 shot injection molding was performed, and after the completion, the state of dirt caused by white deposits on the metal mirror surface of the mold fixing side was confirmed. The following three grades of A, B, and C were used for visual evaluation.
A: The amount of deposits is small B: The amount of deposits is between A and C C: The amount of deposits is large

The drop die shown in FIG. 1 is a die designed such that the resin composition is introduced from the gate G and the generated gas is easily accumulated in the tip P portion. The gate G has a width of 1 mm and a thickness of 1 mm. In FIG. 1, the width h1 is 14.5 mm, the length h2 is 7 mm, the length h3 is 27 mm, and the thickness of the molding portion is 3 mm.
The above evaluation results are shown in Table 2 below.

In the above table, in Comparative Example 6, the molded product was brittle due to decomposition, and continuous molding was impossible. YI is a reference value of what could be sampled.

The polycarbonate resin composition of the present invention is excellent in compatibility, has a good hue, and is a polycarbonate resin composition in which gas generation during molding is extremely small, so that it can be extremely suitably used for various optical members and is industrially used. The sex is very high.

Claims

0.1 to 3 parts by mass of the compound (B) obtained by binding the polyoxytetramethylene glycol polymer (B1) with the alicyclic diol (B2) to 100 parts by mass of the aromatic polycarbonate resin (A), and phosphorus. Contains 0.005 to 0.4 part by mass of the system stabilizer (C),
In the compound (B), the alicyclic diol (B2) component is 20 mass% or less, and the mass ratio of the oxytetramethylene glycol unit in the component excluding the alicyclic diol (B2) component is 55 to 80 mass. %, and the compound (B) has a number average molecular weight of 1000 to 2400, a polycarbonate resin composition for optical members.
The polycarbonate resin composition for optical members according to claim 1, wherein the polyoxytetramethylene glycol-based polymer (B1) is a copolymer containing an oxytetramethylene glycol unit and an oxyalkylene glycol unit other than oxytetramethylene glycol. object.
The polycarbonate for optical members according to claim 1 or 2, further comprising 0.005 to 0.2 parts by mass of the epoxy compound and/or the oxetane compound (D) per 100 parts by mass of the aromatic polycarbonate resin (A). Resin composition.
The polycarbonate resin composition for optical members according to any one of claims 1 to 3, wherein the alicyclic diol (B2) is hydrogenated bisphenol A.
A molded product for an optical member, comprising the polycarbonate resin composition according to any one of claims 1 to 3.
The molded product according to claim 5, which is a light guide for automobile lighting, a light guide for illumination, or a light guide plate for backlight, in which the optical path length of the optical component is 50 mm or more.