JP6623752B2 - A thermoplastic resin composition and a molded article using the same. - Google Patents

Description

  The present invention relates to a polycarbonate resin containing a structural unit derived from a dihydroxy compound having a specific bonding structure, a resin composition comprising a specific light diffusing agent, and a molded article obtained by molding the resin. The present invention relates to a resin composition having excellent light diffusing properties and transparency. The present invention also relates to a molded article utilizing the excellent optical properties of the resin composition of the present invention.

Polycarbonate is generally manufactured using raw materials derived from petroleum resources. However, in recent years, there is a fear that petroleum resources may be depleted, and it is required to provide polycarbonate using a raw material obtained from biomass resources such as plants. Also, since global warming due to the increase and accumulation of carbon dioxide emissions is feared to cause climate change, plant-based monomers that are carbon neutral even after disposal after use are used as raw materials. There is a need for the development of polycarbonate. Above all, it is used for applications requiring light diffusion, such as lighting covers, lighting signs, transmissive screens, various displays, and light diffusion sheets for liquid crystal display devices. A polycarbonate resin having high light transmittance and excellent transparency has been demanded.

Conventionally, various polycarbonates using plant-derived monomers as raw materials have been developed.
For example, it has been proposed to use isosorbide as a plant-derived monomer and obtain a polycarbonate by transesterification with diphenyl carbonate (for example, see Patent Document 1). Further, by copolymerizing isosorbide and an aliphatic diol (for example, see Patent Document 2) or polymerizing 1,4-cyclohexanedimethanol, which is an alicyclic dihydroxy compound (for example, see Patent Document 3), Attempts have been made to improve the physical properties of a homopolycarbonate comprising isosorbide as a resin. Further, it has been proposed to improve the haze and the like of polycarbonate using isosorbide as a raw material by considering the polymerization temperature and catalyst of the polycarbonate and by including a bluing agent (for example, see Patent Document 4).

  In addition, it is described that bead-like crosslinked acrylic particles and the like are added to polycarbonate made from isosorbide as a raw material, and that a light-diffusing thermoplastic resin composition having heat resistance, heat stability and weather resistance, and having excellent hue is provided. (For example, see Patent Document 5).

  Furthermore, a light-diffusing thermoplastic resin having excellent heat resistance and thermal stability, and excellent in hue, weather resistance and rigidity, is obtained by adding core / shell structured acrylic polymer particles to polycarbonate made from isosorbide as a raw material. A composition is described (for example, see Patent Document 6).

UK Patent No. 1079686 WO 04/111106 pamphlet JP 2008-024919 A JP 2012-214665 A JP 2009-191226 A JP 2011-105845 A

  However, in the inventions described in Patent Documents 1 to 4, attention is not paid to the viewpoint of light diffusivity of polycarbonate using isosorbide as a raw material, and no measures are taken to improve the light diffusivity. Therefore, it is not satisfactory from the viewpoint of light diffusion.

  In addition, Patent Documents 5 and 6 describe that bead-like crosslinked acrylic particles and core / shell structured acrylic polymer particles are added to polycarbonate made of isosorbide as a raw material, however, the light diffusivity and the transparency are increased. However, such a configuration does not satisfy the light diffusibility and transparency.

  That is, an object of the present invention is to provide a polycarbonate resin having high haze, excellent light diffusivity, high total light transmittance, and excellent transparency.

  As a result of investigations by the present inventors, by containing a polycarbonate resin containing a structural unit derived from a specific dihydroxy compound and an acrylate / styrene copolymer, the light diffusivity and transparency of a thermoplastic resin composition The present inventors have found that the properties can be improved, and have completed the present invention.

That is, the gist of the present invention is as follows.
[1] A thermoplastic resin composition containing a polycarbonate resin containing a structural unit (a) derived from a dihydroxy compound represented by the following formula (1) and an acrylate / styrene copolymer having a number average particle size of 1 to 20 μm: object.

[2] The thermoplastic resin composition according to [1], wherein the acrylic acid ester / styrene copolymer has a refractive index of 1.50 to 1.58.
[3] When the total amount of the polycarbonate resin and the acrylate / styrene copolymer is 100 parts by weight, the content of the acrylate / styrene copolymer is 0.1 to 5 parts by weight [1]. Or the thermoplastic resin composition according to [2].
[4] The thermoplastic resin composition according to any one of [1] to [3], wherein the reduced viscosity of the polycarbonate resin is from 0.30 dL / g to 1.20 dL / g.
[5] The thermoplastic resin composition according to any one of [1] to [4], which contains a light stabilizer.
[6] The thermoplastic resin composition according to any one of [1] to [5], which contains an antioxidant.
[7] A molded article obtained by molding the thermoplastic resin composition according to any one of [1] to [6].

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in light-diffusion property and transparency, For example, the use which requires light-diffusion property, such as a light diffusion sheet, such as a lighting cover, a lighting signboard, a transmission type screen, various displays, and a liquid crystal display device. It is possible to provide a thermoplastic resin composition that can be suitably used and a molded article obtained by molding the same.

  Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention is described below unless the gist thereof is exceeded. It is not limited to the content of.

<Polycarbonate resin (A)>
The polycarbonate resin (A) used in the present invention is a polycarbonate resin containing a structural unit (a) derived from a dihydroxy compound represented by the following formula (1).

  Examples of the dihydroxy compound represented by the above formula (1) include isosorbide, isomannide, and isoidet, which are in a stereoisomeric relationship. These may be used alone or in combination of two or more. You may. Above all, isosorbide obtained by dehydrating and condensing sorbitol, which is abundant as a plant-derived resource and produced from various readily available starches, is easy to obtain and produce, moldability, heat resistance, impact resistance It is most preferable in terms of properties, surface hardness and carbon neutrality.

  Since the dihydroxy compound represented by the formula (1) has a cyclic ether structure, it is easily oxidized gradually by oxygen. Therefore, at the time of storage or production, in order to prevent decomposition by oxygen, moisture is prevented from being mixed. It is important to use an oxygen scavenger or the like or to handle in a nitrogen atmosphere. For example, when isosorbide is oxidized, a decomposition product such as formic acid may be generated. When isosorbide containing these decomposed products is used as a raw material for producing a polycarbonate resin, there is a possibility that the obtained polycarbonate resin and thermoplastic resin composition may be colored, and not only may physical properties be significantly deteriorated, In some cases, it affects the polymerization reaction and a high molecular weight polymer cannot be obtained.

  The polycarbonate resin (A) used in the present invention includes, in addition to the structural unit (a) derived from the dihydroxy compound represented by the formula (1), an aliphatic dihydroxy compound, an alicyclic dihydroxy compound, an aromatic bisphenol and a compound represented by the formula Structural units (b) derived from one or more dihydroxy compounds selected from the group consisting of ether-containing dihydroxy compounds other than the dihydroxy compound represented by (1) (hereinafter sometimes referred to as “other dihydroxy compounds”). ) Is preferred in view of the impact resistance of the polycarbonate resin (A). Among them, one or more dihydroxy compounds selected from the group consisting of aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, and aromatic bisphenols are preferable, and from the viewpoint of the light resistance of the polycarbonate resin, an aromatic ring structure is included in the molecular structure. A dihydroxy compound which is not used, that is, an aliphatic dihydroxy compound and / or an alicyclic dihydroxy compound is more preferable. In consideration of heat resistance, an alicyclic dihydroxy compound is most preferable.

  The aliphatic dihydroxy compound may be a straight-chain aliphatic dihydroxy compound or a branched-chain aliphatic dihydroxy compound, for example, ethylene glycol, 1,3-propanediol, 1,2-propanediol, , 4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-heptanediol, 1,6-hexanediol, 1,10-decanediol and the like.

  Examples of the alicyclic dihydroxy compound include 1,2-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, 1,4-cyclohexane dimethanol, tricyclodecane dimethanol, pentacyclopentadecane dimethanol, and 2,6-decalin Examples include methanol, 1,5-decalin dimethanol, 2,3-decalin dimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, and 1,3-adamantane dimethanol.

  As aromatic bisphenols, 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A], 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis ( 4-hydroxy-3,5-diethylphenyl) propane, 2,2-bis (4-hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl ) Propane, 2,2-bis (4-hydroxyphenyl) pentane, 2,4′-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-5-nitrophenyl) methane, 1,1 -Bis (4-hydroxyphenyl) ethane, 3,3-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydr (Xyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4′-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3 ′ -Dichlorodiphenyl ether, 9,9-bis (4- (2-hydroxyethoxy-2-methyl) phenyl) fluorene, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-2) -Methylphenyl) fluorene.

  Examples of the ether group-containing dihydroxy compound include diethylene glycol, triethylene glycol, polyethylene glycol (molecular weight: 150 to 2,000), poly-1,3-propylene glycol, polytetramethylene glycol, and the like.

  The content ratio of the structural unit (b) derived from another dihydroxy compound in the polycarbonate resin (A) used in the present invention is 10 mol% or more in all the structural units derived from the dihydroxy compound in the polycarbonate resin (A). It is preferably at least 20 mol%, more preferably at least 30 mol%. Further, it is preferably at most 50 mol%, more preferably at most 45 mol%. If the structural unit (b) derived from another dihydroxy compound in the polycarbonate resin (A) is too small, the impact resistance may be insufficient, and if it is too large, the heat resistance may be insufficient.

The polycarbonate resin (A) used in the present invention can be produced by a generally used method for producing a polycarbonate resin. The production method includes a solution polymerization method using phosgene, and a melting method in which a diester carbonate is reacted with a dihydroxy compound. Although any polymerization method may be used, a melt polymerization method in which a dihydroxy compound containing the dihydroxy compound represented by the formula (1) is reacted with a carbonic acid diester having lower environmental toxicity in the presence of a polymerization catalyst is preferable. . As the polymerization catalyst (transesterification catalyst) in the melt polymerization, a known alkali metal compound and / or alkaline earth metal compound is used. It is also possible to use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound together with the alkali metal compound and / or the alkaline earth metal compound.

  As described above, the polycarbonate resin (A) used in the present invention can be produced by subjecting a dihydroxy compound containing the dihydroxy compound represented by the formula (1) to a transesterification reaction of a diester carbonate such as diphenyl carbonate. More specifically, it can be obtained by subjecting a transesterification reaction to remove a by-product monohydroxy compound or the like out of the system. In this case, usually, melt polymerization is performed by a transesterification reaction in the presence of a transesterification catalyst.

  Examples of the transesterification catalyst (hereinafter sometimes referred to as “catalyst”) which can be used in the production of the polycarbonate resin (A) used in the present invention include, for example, a long-period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). And a basic compound such as a metal compound of group 1 or 2 (hereinafter simply referred to as "group 1" or "group 2"), a basic boron compound, a basic phosphorus compound, a basic ammonium compound, an amine compound or the like. Compounds. Among these, Group 1 metal compounds and / or Group 2 metal compounds are preferably used, and Group 2 metal compounds are particularly preferably used in terms of transparency and weather resistance.

It is also possible to use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound together with the group 1 metal compound and / or the group 2 metal compound. It is particularly preferred to use only Group 1 metal compounds and / or Group 2 metal compounds.
The group 1 metal compound and / or group 2 metal compound is usually used in the form of a hydroxide or a salt such as a carbonate, a carboxylate, or a phenol. Hydroxides, carbonates, and acetates are preferred from the viewpoint of easiness, and acetates are preferred from the viewpoint of hue and polymerization activity.

  Examples of the Group 1 metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, Cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride Sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, sodium hydrogen phosphate System, 2 potassium hydrogen phosphate, 2 lithium hydrogen phosphate, 2 cesium hydrogen phosphate, 2 sodium phenyl phosphate, 2 potassium phenyl phosphate, 2 lithium phenyl phosphate, 2 cesium phenyl phosphate, sodium, potassium, lithium, Cesium alcoholate, phenolate, bisphenol A disodium salt, dipotassium salt, dilithium salt, dicesium salt and the like are preferable, among which cesium compounds and lithium compounds are preferable.

  Examples of the Group 2 metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, Examples include strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, among which magnesium compounds, calcium compounds, barium compounds are preferable, and magnesium compounds and / or Or a calcium compound is more preferred.

  Examples of the basic boron compound include, for example, tetramethyl boron, tetraethyl boron, tetrapropyl boron, tetrabutyl boron, trimethyl ethyl boron, trimethyl benzyl boron, trimethyl phenyl boron, triethyl methyl boron, triethyl benzyl boron, triethyl phenyl boron, tributyl benzyl Examples include sodium, potassium, lithium, calcium, barium, magnesium, and strontium salts such as boron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, and butyltriphenylboron. Can be

Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.
Examples of the basic ammonium compound include, for example, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydro Sid, butyl triphenyl ammonium hydroxide, and the like.

  Examples of the amine compound include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, -Dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like.

Among the above, the use of at least one metal compound selected from the group consisting of Group 2 metal compounds as a catalyst is excellent in various physical properties such as transparency, hue, and light resistance of the obtained polycarbonate resin (A). It is preferable to use
Further, in order to make the polycarbonate resin (A) particularly excellent in transparency, hue and light resistance, the catalyst is at least one metal compound selected from the group consisting of a magnesium compound, a calcium compound and a barium compound. Is preferable, and at least one metal compound selected from the group consisting of a magnesium compound and a calcium compound is particularly preferable.

In the case of a Group 1 metal compound and / or a Group 2 metal compound, the amount of the catalyst used is preferably 0.1 to 300 μmol, more preferably 0.1 to 300 μmol, in terms of metal, based on 1 mol of all dihydroxy compounds to be subjected to the reaction. It is in the range of 0.1-100 mol, more preferably 0.5-50 mol, particularly preferably 1-25 mol.
When a compound containing at least one metal selected from the group consisting of Group 2 metals is used among the above, the metal equivalent is preferably 0.1 μmol or more, more preferably 1 μmol or more, per 1 mol of all dihydroxy compounds to be subjected to the reaction. Is 0.5 μmol or more, particularly preferably 0.7 μmol or more. The upper limit is preferably 20 μmol, more preferably 10 μmol, particularly preferably 3 μmol, and most preferably 2.0 μmol.

If the amount of the catalyst is too small, the polymerization activity required for producing the polycarbonate resin (A) having a desired molecular weight cannot be obtained, and sufficient breaking energy may not be obtained. On the other hand, if the amount of the catalyst used is too large, not only the hue of the obtained polycarbonate resin (A) is deteriorated, but also by-products are generated and the flowability is reduced and the generation of gel is increased, resulting in brittle fracture. And the production of the target quality polycarbonate resin (A) may be difficult.
In addition, in the thermoplastic resin composition of the present invention, the amount of the metal used as the catalyst is included in the thermoplastic resin composition derived from the catalyst used for producing the polycarbonate resin. Therefore, the amount of the metal used as the catalyst in the thermoplastic resin composition is the same as the above-specified range.

As the type of the polymerization reaction, a known type can be used, and any method of a batch type, a continuous type, or a combination of a batch type and a continuous type may be used.
When the polycarbonate resin (A) used in the present invention is produced, it is desirable to install a filter in order to prevent foreign substances from being mixed. The installation position of the filter is preferably on the downstream side of the extruder, and the size (opening) of foreign matter removal of the filter is usually preferably 100 μm or less as a filtration accuracy of 99% removal. In particular, when it is desired to avoid the inclusion of minute foreign matter in film applications, the thickness is preferably 40 μm or less, and more preferably 10 μm or less.

The extrusion of the polycarbonate resin (A) used in the present invention is preferably a class 7 defined in JIS B 9920 (2002), and more preferably a higher cleanness than class 6, in order to prevent foreign matter from being mixed after the extrusion. It is desirable to carry out in a clean room.
When the extruded polycarbonate resin (A) is cooled and formed into chips, it is preferable to use a cooling method such as air cooling or water cooling. The air used for air cooling is preferably air from which foreign substances in the air have been removed in advance using a hepa filter or the like, to prevent the foreign substances in the air from re-adhering. When using water cooling, it is desirable to use water in which metal components in water are removed with an ion exchange resin or the like, and further, foreign matter in the water is removed with a filter. The aperture of the filter used is preferably 10 μm to 0.45 μm as a filtration accuracy of 99% removal.

The molecular weight of the polycarbonate resin (A) used in the present invention can be represented by a reduced viscosity. The reduced viscosity is usually preferably at least 0.30 dL / g, more preferably at least 0.35 dL / g. The upper limit of the reduced viscosity is usually preferably 1.20 dL / g or less, more preferably 1.00 dL / g or less, and still more preferably 0.80 dL / g or less.
If the reduced viscosity of the polycarbonate resin (A) is too low, the toughness of the resin composition may be low, and if the reduced viscosity is too large, the flow during molding of electric / electronic device parts and automotive interior / exterior parts is reduced. Properties and the productivity and moldability tend to decrease. In addition, the molding temperature must be higher than appropriate, and the color tone may deteriorate.
The reduced viscosity of the polycarbonate resin is measured using a Ubbelohde viscosity tube at a temperature of 20.0 ° C. ± 0.1 ° C. using methylene chloride as a solvent, precisely adjusting the polycarbonate resin concentration to 0.6 g / dL. .

The glass transition temperature of the polycarbonate resin (A) used in the present invention is preferably from 90 ° C to 145 ° C, more preferably from 100 ° C to 135 ° C, particularly preferably from 110 ° C to 125 ° C. If the glass transition temperature is less than 90 ° C., the heat resistance is insufficient, and if the glass transition temperature is 145 ° C. or more, the fluidity is insufficient at the time of molding, and the resin composition is not filled to the end of the product or the strength at the weld portion is reduced. There is.
The total light transmittance and haze of the polycarbonate resin (A) of the present invention can be measured by the following methods.

(1) Pellet production A polycarbonate resin in a molten state is continuously supplied to a twin-screw extruder provided with three vent ports and a water injection facility, and Irganox 1010 (as an antioxidant, based on 100 parts by mass of the polycarbonate resin) 0.1 parts by mass of pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] manufactured by BASF Japan Ltd. and ADK STAB 2112 (Tris (made by ADEKA Corporation) 0.05 parts by mass of 2,4-di-tert-butylphenyl) phosphite) and 0.3 parts by mass of Unistar E-275 (manufactured by NOF CORPORATION) as a releasing agent were continuously added. After devolatilizing low-molecular-weight substances such as phenol under reduced pressure at each vent of the screw extruder, Perform pelletization.

(2) Injection molding The pellets preliminarily dried at 80 ° C. for 4 hours with respect to the pellets kneaded by the twin-screw extruder were subjected to a cylinder temperature of 230 ° C., a molding cycle of 45 seconds, and a mold temperature of 60 by a J75EII type injection molding machine manufactured by Nippon Steel Works. At 60 ° C., a flat plate of 60 mm × 60 mm × 3 mmt is formed.

(2) Measurement of haze and total light transmittance Using a haze meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd., the haze (Haze (%)) and total light transmittance (%) of the above test pieces were measured with a D65 light source. Measure. The total light transmittance of the polycarbonate resin (A) of the present invention is preferably 85% or more, more preferably 88% or more, and particularly preferably 90% or more. If this light transmittance is higher than the above lower limit, the total light transmittance of the thermoplastic resin composition becomes high. Details of the method for measuring the light transmittance will be described in the section of Examples.

The polycarbonate resin (A) of the present invention has a haze based on JIS K7105 of usually 2 or less, preferably 1.5 or less, and most preferably 1 or less. When the haze is within the above range, a high total light transmittance and a high haze can both be achieved when the thermoplastic resin composition is used.
In the thermoplastic resin composition of the present invention, one type may be used alone as the polycarbonate resin (A), and the types of structural units derived from other dihydroxy compounds, copolymerization ratios, and physical properties may be different. These may be used as a mixture of two or more.

<Acrylic acid ester / styrene copolymer>
[3] Light Diffusing Agent The resin composition of the present invention contains an acrylate / styrene copolymer as a light diffusing agent. By containing the acrylate / styrene copolymer as the light diffusing agent in this way, the light diffusibility and transparency of the resin composition of the present invention and a molded article formed therefrom can be enhanced.

  Acrylate / styrene copolymers are fine particles obtained by copolymerizing an acrylic ester monomer and a styrene monomer.For example, an acrylic ester monomer and a styrene monomer are polymerized by a suspension polymerization method or the like. It is preferable that the fine particles are crosslinked with a crosslinking agent. Examples of acrylic ester monomers include, for example, methacrylate monomers such as methyl methacrylate and ethyl methacrylate; acrylate monomers such as methyl acrylate and ethyl acrylate; and acrylamide. Representative examples thereof include styrene and α- Methylstyrene, vinyltoluene and the like can be exemplified as typical examples. In the copolymerization of these monomers, these monomers may be used as a main component and other monomers may be copolymerized as necessary. Examples of the cross-linking agent include generally used cross-linking agents, for example, ethylene glycol dimethacrylate, divinylbenzene, 1,6-hexanediol, trimethylpropane trimethacrylate, trimethylpropane trimethacrylate, and trimethylpropane triacrylate. Functional monomers can be used.

The number average particle diameter of the acrylate / styrene copolymer is 1 to 20 μm, preferably 1.5 to 18 μm, more preferably 2 to 16 μm, further preferably 4 to 14 μm, and most preferably 6 to 12 μm. If the particle diameter is in the above range, the light diffusibility and transparency are sufficient, the light source is suppressed from being seen through, the diffusion effect on the added amount is good, and when an LED light source is used, Glare is prevented and visibility is excellent.

The number average particle diameter of the acrylate / styrene copolymer can be measured by the following method.
That is, the measurement can be performed using a laser particle measuring device MICROTRAC MT-3000 manufactured by Nikkiso Co., Ltd. as a measuring device.
The refractive index of the acrylate-styrene copolymer is 1.493 to 1 by changing the copolymerization ratio of the acrylate-based monomer and the styrene-based monomer in the range of 99: 1 to 1:99. .590. However, if the copolymerization ratio of the styrene-based monomer is too high, the light resistance is reduced and a yellow tint is obtained, and if the copolymerization ratio of the acrylic ester-based monomer is too high, the fine particles and the aromatic polycarbonate are used. The difference in the refractive index of the LED light source is too large, and the glare of the LED light source is conspicuous, and the visibility is low. Accordingly, the refractive index of the acrylate-styrene copolymer is preferably from 1.50 to 1.58, more preferably from 1.51 to 1.57, and still more preferably from 1.52 to 1.56. Use those.

  In order to obtain fine particles having such a refractive index, it is necessary to adjust the copolymerization ratio between the acrylic ester monomer and the styrene monomer. Although the adjustment ratio varies depending on the monomer used, the refractive index becomes lower when more acrylic ester-based monomers are used, and becomes higher when more styrene-based monomers are used. For example, when methyl methacrylate is used as the acrylic ester monomer and styrene is used as the styrene monomer, and when the refractive index is adjusted to about 1.52, the ratio of the acrylic ester monomer to the styrene monomer is about 7: 3. When the refractive index is adjusted to about 1.56, the ratio is about 3: 7.

The acrylate / styrene copolymer as a light diffusing agent can be synthesized by an emulsion polymerization method, and a commercially available product can also be used.
As the acrylic ester / styrene copolymer usable in the present invention, those available from the market may be used. Examples of such commercially available products include, for example, the GBS series or GSM series commercially available from Ganz Kasei Co., Ltd. under the trade name of Gantz Pearl or Staphyloid, which conform to the physical properties specified in the present invention. To do.

More specifically, Gantz Pearl GSM-0853S, Gantz Pearl GSM-0855S, GSM-0851S, GSM-0858S, GSM-1050S and the like can be mentioned.
One type of light diffusing agent may be used, or two or more types may be used in any combination and in any ratio. Further, when two or more kinds are mixed, the number average particle diameter measured when the two or more kinds are mixed may be the above-mentioned number average particle diameter.

The content of the light diffusing agent in the light diffusing resin composition of the present invention, when the total amount of the polycarbonate resin and the acrylate-styrene copolymer is 100 parts by weight, the acrylate-styrene copolymer The content is preferably from 0.1 to 5 parts by weight, more preferably from 0.25 to 4 parts by weight, even more preferably from 0.5 to 3 parts by weight. When the content of the light diffusing agent is within the above range, the molded article made of the resin composition has sufficient light diffusing property, and the light source can be seen through when used as a lighting fixture member, a diffusion plate, or the like. Is suppressed. Further, the molded article of the present invention has good light transmittance, and when used as a lighting fixture member, a diffusion plate, or the like, the possibility that the luminance becomes excessively low is suppressed.

<Additives>
In the thermoplastic resin composition of the present invention, an antioxidant, a light stabilizer, an ultraviolet absorber, a release agent, a colorant, a neutralizing agent, an antistatic agent, as long as the effect of suppressing the generation of squeak noise can be maintained. Lubricants, lubricants, plasticizers, flame retardants, fillers and the like can also be added.

(Antioxidant)
As the antioxidant, general antioxidants used for resins can be used, but from the viewpoints of oxidation stability, heat stability, jet blackness, etc., phosphite antioxidants, sulfur antioxidants, and Phenolic antioxidants are preferred.
When an antioxidant is added to the thermoplastic resin composition of the present invention, the addition amount is usually preferably 0.001 part by mass or more, more preferably 0.002 part by mass, per 100 parts by mass of the polycarbonate resin (A). It is at least 0.005 parts by mass, more preferably at least 0.005 parts by mass, usually at most 5 parts by mass, more preferably at most 3 parts by mass, even more preferably at most 2 parts by mass.
If the amount of the antioxidant is more than 5 parts by mass, the mold may be contaminated during molding, and a molded article having excellent surface appearance may not be obtained. On the other hand, if the amount is less than 0.001 part by mass, there is a tendency that a sufficient improvement effect on the weather resistance test cannot be obtained.

<Phosphite antioxidant>
Examples of phosphite-based antioxidants include triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, and trioctadecyl. Phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis (2,6-di-tert- Butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (nonylphenyl) pentaerythritol Diphosphite, bis (2,4-di -tert- butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, and the like.
Among these, trisnonylphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6 -Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferably used.
These compounds may be used alone or in combination of two or more.

<Sulfur antioxidant>
Examples of the sulfur-based antioxidants include dilauryl-3,3′-thiodipropionate, ditridecyl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, Stearyl-3,3'-thiodipropionate, laurylstearyl-3,3'-thiodipropionate, pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-laurylthiopropionate) ), Glycerol-3-stearylthiopropionate, bis [2-methyl-4- (3-laurylthiopropionyloxy) -5-tert-butylphenyl] sulfide, octadecyldisulfide, mercaptobenzimidazole, 2-mercapto-6 -Methylbenzy Imidazole, 1,1'-thiobis (2-naphthol), and the like.
Among these, pentaerythritol tetrakis (3-laurylthiopropionate) is preferred.
These compounds may be used alone or in combination of two or more.

<Phenolic antioxidant>
Examples of the phenolic antioxidant include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] and 1,6-hexanediol-bis [3- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate], pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,3 5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3, 5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris ( , 5-Di-tert-butyl-4-hydroxybenzyl) isocyanurate, tetrakis (4,4′-biphenylenediphosphinic acid) (2,4-di-tert-butylphenyl), 3,9-bis {1,1-dimethyl -2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} -2,4,8,10-tetraoxaspiro (5,5) undecane, 2,6- Compounds such as di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-ethylphenol are exemplified.

Among these compounds, an aromatic monohydroxy compound substituted by one or more alkyl groups having 5 or more carbon atoms is preferable. Specifically, octadecyl-3- (3,5-di-tert-butyl-4-butyl) is preferred. Hydroxyphenyl) propionate, pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert) -Butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and the like, and pentaerythritol- Tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] A further preferred.
These compounds may be used alone or in combination of two or more.

(Light stabilizer)
Examples of the light stabilizer include a hindered amine light stabilizer, and the molecular weight is preferably 1,000 or less, more preferably 900 or less. If the molecular weight exceeds 1,000, there is a possibility that sufficient weather resistance may not be obtained when a molded article is formed. Further, the molecular weight is preferably 300 or more, and more preferably 400 or more. If the molecular weight is less than 300, the heat resistance is poor, the mold is contaminated during molding, and a molded article having excellent surface appearance may not be obtained.
Further, compounds having a piperidine structure are preferred. The piperidine structure defined here may be a saturated 6-membered ring amine structure, and includes those in which a part of the piperidine structure is substituted with a substituent. Examples of the substituent include an alkyl group having 4 or less carbon atoms, and a methyl group is particularly preferable.
As the hindered amine light stabilizer, a compound having a plurality of piperidine structures is particularly preferable, and a compound in which the plurality of piperidine structures are linked by an ester structure is preferable.

Such light stabilizers include 4-piperidinol, 2,2,6,6-tetramethyl-4-benzoate, bis (2,2,6,6-tetramethyl-piperidyl) sebacate, bis (1,2 , 2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethylpiperidine-4-carboxylic acid) 1,2,3,4-butanetetrayl, 2,2 6,6-tetramethyl-pyreridinol, tridecyl alcohol and 1,
Condensate of 2,3,4-butanetetracarboxylic acid, condensate of 2,2,6,6-tetramethyl-pyrreridinol and methanol with 1,2,3,4-butanetetracarboxylic acid, bis (1,2 , 3,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butylmalonate, bis (2,2,6 , 6-Tetramethyl-1- (octyloxy) -4-piperidinyl) ester, the reaction product of 1,1-dimethylethyl hydroperoxide and octane, 1- [2- [3- (3,5-di-tert) -Butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4,4-hydroxyphenyl) propionyloxy] ethyl] -2 2,6,6-tetramethylpiperidine, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, poly [{6- (1,1 , 3,3-Tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene} (2 2,6,6-tetramethyl-4-piperidyl) imino}], N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) -1,6-hexanediamine polymer and 2, Condensate with 4,6-trichloro-1,3,5-triazine, 1,2,3,4-butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinol and β, β, β, β-tetramethyl-3,9- (2,4 Condensate with 8,10-tetraoxaspiro [5,5] undecane-diethanol, N, N′-bis (3-aminopropyl) ethylenediamine and 2,4-bis [N-butyl-N- (1,2 , 2,6,6-Pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine, dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2 , 2,6,6-tetramethylpiperidine.

  When a light stabilizer is added to the thermoplastic resin composition of the present invention, the addition amount is usually 0.001 part by mass or more and 5 parts by mass or less based on 100 parts by mass of the polycarbonate resin (A). The content is 0.005 to 3 parts by mass, more preferably 0.01 to 1 part by mass. If the amount of the light stabilizer is more than 5 parts by mass, coloring tends to occur, and even if a coloring agent is added, it is difficult to obtain, for example, jet black having a deep and clear feeling. On the other hand, if the amount is less than 0.001 part by mass, sufficient weather resistance may not be obtained when the product is used as an interior / exterior product for an automobile.

<Production method of thermoplastic resin composition>
The thermoplastic resin composition of the present invention is obtained by mixing the above components at a predetermined ratio simultaneously or in an arbitrary order by a mixer such as a tumbler, a V-type blender, a Nauter mixer, a Banbury mixer, a kneading roll, an extruder, or the like. Can be manufactured.

<Molded product>
When molding a molded article using the thermoplastic resin composition of the present invention, any molding method can be used, but injection molding, injection compression, and injection press molding are preferably used. The runner used at that time may be not only a normal cold runner system but also a hot runner system. Also, insert molding, in-mold coating molding, two-color molding, sandwich molding and the like are possible. Further, in order to obtain a design property, it is also possible to use heat-insulating mold molding and rapid heating / cooling mold molding.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following, the property evaluation of the light diffusing resin composition was performed by the following method.

(1) Injection molding The pellets kneaded with a twin-screw extruder were predried at 80 ° C. for 4 hours, and the pellets were molded at a cylinder temperature of 230 ° C., a molding cycle of 45 seconds, and a mold temperature of 60 with a J75EII type injection molding machine manufactured by Nippon Steel Works. At 60 ° C., a flat plate of 60 mm × 60 mm × 3 mmt was formed.
(2) Measurement of haze and total light transmittance Using a haze meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd., the haze (HAZE (%)) and total light transmittance (%) of the above test pieces were measured with a D65 light source. It was measured.
(3) Comprehensive Judgment The case where the haze was 90% or more and the total light transmittance was 90% or more was judged as pass, and the other cases were judged as failed.
The resins used in the following Examples and Comparative Examples were polycarbonate resins produced by the methods described in the following Production Examples, and the following commercial products were used as additives.

<Polycarbonate resin>
[Production Example 1: Production of polycarbonate resin (A) -1]
Isosorbide (ISB) and 1,4-cyclohexanedimethanol (CHDM) were distilled and purified in a polymerization reactor equipped with a stirring blade and a reflux condenser controlled at 100 ° C., and diphenyl chloride having a chloride ion concentration of 10 ppb or less was obtained. The molar ratio of carbonate (DPC) and calcium acetate monohydrate to ISB / CHDM / DPC / calcium acetate monohydrate was 0.7 / 0.3 / 1.00 / 1.3 × 10 ^{−. 6} and sufficiently purged with nitrogen (oxygen concentration 0.0005% by volume to 0.001% by volume). Subsequently, the content was heated with a heating medium. Stirring was started when the internal temperature reached 100 ° C, and the contents were melted and made uniform while controlling the internal temperature to 100 ° C. Thereafter, the temperature was raised, and the internal temperature was raised to 210 ° C. in 40 minutes. When the internal temperature reaches 210 ° C., the temperature is controlled so as to be maintained at the same time. At the same time, pressure reduction is started, and 90 minutes after the temperature reaches 210 ° C., 13.3 kPa (absolute pressure, the same applies hereinafter). The pressure was maintained while maintaining the pressure for an additional 60 minutes. Phenol vapor by-produced during the polymerization reaction was led to a reflux condenser. The components condensed in the reflux condenser were returned to the polymerization reactor, and the uncondensed phenol vapor was subsequently collected by introducing it into a condenser using hot water at 45 ° C. as a refrigerant.

After the content oligomerized in the above polymerization reactor is once returned to atmospheric pressure, it is transferred to another polymerization reactor equipped with a stirring blade and a reflux condenser controlled in the same manner as above, and the temperature is raised and The pressure reduction was started, and the internal temperature was set to 220 ° C. and the pressure to 200 Pa in 60 minutes. Thereafter, the internal temperature was reduced to 228 ° C. and the pressure was set to 133 Pa or lower over 20 minutes, and the pressure was restored when a predetermined stirring power was reached, and a polycarbonate resin in a molten state was obtained from the polymerization reactor outlet.
Further, the polycarbonate resin in the molten state was continuously supplied to a twin-screw extruder provided with three vent ports and a water injection device, and Irganox 1010 (BASF Japan) was used as an antioxidant with respect to 100 parts by mass of the polycarbonate resin. 0.1 parts by mass of pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] manufactured by ADEKA CORPORATION and Tris (2,4 manufactured by ADEKA Corporation) -Di-tert-butylphenyl) phosphite) and Unistar E-275 (manufactured by NOF CORPORATION) 0.3 part by mass as a releasing agent were continuously added, and a twin-screw extruder was used. After devolatilizing low-molecular-weight substances such as phenol at reduced pressure at each vent provided in the Performs reduction, to obtain a polycarbonate resin (A) -1. The reduced viscosity η _sp / c of the polycarbonate resin (A) -1 was 0.44 dL / g.
The abbreviations of the compounds used in the following Examples and Comparative Examples are as follows.

<Diffusing agent>
GM-0853S: acrylate / styrene copolymer, refractive index: 1.53, number average particle size: 8 μm
(Manufactured by Aika Kogyo Co., Ltd., trade name: Gantz Pearl GM-0853S)
GM-0855S: Acrylic ester / styrene copolymer, refractive index: 1.55, number average particle diameter: 8 μm
(Manufactured by Aika Kogyo Co., Ltd., Gantz Pearl GM-0855S)
SI-045: polymethylsilsesquioxane, refractive index: 1.41, number average particle diameter: 4 μm
(Manufactured by Aika Kogyo Co., Ltd., trade name: Gantz Pearl SI-045)
GM-0806S: polyacrylate, refractive index: 1.49, number average particle diameter: 8 μm
(Manufactured by Aika Kogyo Co., Ltd., Gantz Pearl GM-0855S)
GS-1105: polystyrene, refractive index: 1.59, number average particle diameter: 11 µm
(Made by Aika Kogyo Co., Ltd., Gantz Pearl GS-1105)

<Light Stabilizer>
TINUVIN 329: Benzotriazole-based UVA (product name “TINUVIN” (registered trademark) 329, manufactured by BASF)
TINUVIN770DF: HALS (manufactured by BASF, product name "TINUVIN" (registered trademark) 770DF)

[Example 1]
Nippon Steel Works, Ltd. having two vent ports of polycarbonate resin (A) -1, diffusing agent GM-0853S, and tinuvin 329 and tinuvin 770DF as light stabilizers so as to have the composition (parts by weight) shown in Table 1 above. Using a twin-screw extruder (LABOTEX30HSS-32), the resin was extruded in a strand shape so that the resin temperature at the outlet of the extruder became 250 ° C, cooled and solidified with water, and then pelletized with a rotary cutter. At this time, the vent port was connected to a vacuum pump, and the pressure at the vent port was controlled to be 500 Pa. The thermoplastic resin composition was evaluated, and the results are shown in Table 1.

[Example 2]
The same operation as in Example 1 was performed except that GM-0853S was changed to GM-0855 as a diffusing agent. The results are shown in Table 1.
[Comparative Example 1]
The same operation as in Example 1 was performed except that GM-0853S was changed to SI-045 as a diffusing agent. The results are shown in Table 1.

[Comparative Example 2]
Example 1 was repeated except that GM-0853S was changed to GM-0806S as a diffusing agent. The results are shown in Table 1.
[Comparative Example 3]
The same operation as in Example 1 was performed except that GM-0853S was changed to GS-1105 as a diffusing agent. The results are shown in Table 1.
[Comparative Example 4]
The same procedure as in Example 1 was carried out except that the diffusing agent was not added. The results are shown in Table 1.

Claims (7)

A thermoplastic resin composition containing a polycarbonate resin containing a structural unit (a) derived from a dihydroxy compound represented by the following formula (1) and an acrylate / styrene copolymer having a number average particle size of 1 to 20 μm.

  The thermoplastic resin composition according to claim 1, wherein the acrylic acid ester / styrene copolymer has a refractive index of 1.50 to 1.58.   The content of the acrylate / styrene copolymer is 0.1 to 5 parts by weight when the total amount of the polycarbonate resin and the acrylate / styrene copolymer is 100 parts by weight. The thermoplastic resin composition according to the above.   The thermoplastic resin composition according to any one of claims 1 to 3, wherein the reduced viscosity of the polycarbonate resin is 0.30 dL / g or more and 1.20 dL / g or less.   The thermoplastic resin composition according to any one of claims 1 to 4, further comprising a light stabilizer.   The thermoplastic resin composition according to any one of claims 1 to 5, further comprising an antioxidant. A molded article obtained by molding the thermoplastic resin composition according to any one of claims 1 to 6.