JP2011157536A - Polycarbonate resin composition and molded product made of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate resin composition which is excellent in mechanical characteristics such as shock resistance, is excellent in the total light transmittance, and light diffusion property and dispersion and is excellent also in molding property, and to provide a molded product made of the polycarbonate resin composition. <P>SOLUTION: The polycarbonate resin composition is characterized in that, based on 100 pts.mass of polycarbonate resin (A), 0.1 to 5 pts.mass of acrylic resin based fine particles (B) in which (i) the average particle size measured on a number basis in the diameter range of 0.4 to 12 μm according to the Coulter counter method is 1 to 4 μm, (ii) the proportion of particles having a particle size of 1 μm or more and less than 2 μm, the proportion of particles having a particle size of 2 μm or more and less than 3 μm and the proportion of particles having a particle size of 3 μm or more fall into the range of 20 to 40 % respectively and (iii) the particle having a particle size of 10 μm or more is not substantially contained. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polycarbonate resin composition and a molded article comprising the same, and in particular, without impairing the mechanical properties of the polycarbonate resin, such as excellent impact resistance, excellent total light transmittance, light diffusivity, and dispersibility, and The present invention relates to a polycarbonate resin composition excellent in moldability and a molded product comprising the same.

  Polycarbonate resin has a wide range of uses as a thermoplastic resin with excellent impact resistance, heat resistance, and transparency, and is lighter and more productive than inorganic glass, providing light diffusibility. By doing so, it can be suitably used for applications that require light diffusibility, such as lighting covers, lighting signs, transmissive screens, various displays, and light diffusion sheets for liquid crystal display devices.

  Addition of inorganic compounds such as glass, silica, and aluminum hydroxide has been proposed to impart light diffusibility to polycarbonate resin, but the thermal stability during molding and extrusion is low, impact strength, etc. There is a drawback that the mechanical strength is greatly lowered. As a light diffusing polycarbonate resin improved in such a drawback, for example, Patent Document 1 discloses that the refractive index is larger than that of the polycarbonate resin and the weight average particle size is 0.5 to 0.5. A light diffusing polycarbonate resin to which polymethyl methacrylate fine particles in the range of 100 μm are added is disclosed. However, in this method, the haze is not sufficient and the practicality is inferior.

Patent Document 2 discloses a high transmittance light made of a polycarbonate resin having a total light transmittance of 85% or more and a diffuse transmittance of 10 to 30%, in which fine particles having a particle size of 50 μm or less and an average particle size of 5 to 20 μm are blended. Although a diffusion plate is disclosed, the light diffusibility is low and the practicality is inferior.
Patent Document 3 discloses a polycarbonate resin composition to which calcium carbonate, titanium oxide, and polyorganohydrogensiloxane are added as a resin composition having excellent light transmittance and light diffusibility. However, thermal stability and impact resistance are disclosed. However, the total light transmittance was not sufficient.

  Patent Document 4 discloses a light diffusing plate for a direct backlight of a polycarbonate resin formed from a composition in which transparent fine particles having an average particle diameter of 1 to 30 μm and a fluorescent brightening agent are blended. Since the brightness is improved by using an agent, the thermal stability is insufficient, discoloration at the time of molding, extrusion, and discoloration at the time of recycling are likely to occur, which is also less practical.

Japanese Patent Laid-Open No. 03-143950 Japanese Patent Laid-Open No. 05-257002 JP 2000-169695 A JP 2004-029091 A

  In view of the above-mentioned problems of the prior art, the object of the present invention is excellent in total light transmittance, light diffusibility, dispersibility, and moldability without impairing mechanical properties such as impact resistance of the polycarbonate resin itself. An object is to provide an excellent polycarbonate resin composition and a molded article comprising the same.

  As a result of intensive studies in order to achieve the above-mentioned problems, the present inventor has blended polycarbonate resin with a specific average particle size of acrylic resin-based fine particles and a specific particle size distribution among them. Then, it was found that a polycarbonate resin composition having excellent mechanical properties such as impact resistance, total light transmittance, light diffusibility, dispersibility, and excellent moldability was obtained, and the present invention was completed. It came.

  That is, according to 1st invention of this invention, the average particle diameter measured on the number basis in the range of 0.4-12 micrometers in diameter by (i) Coulter counter method is 1 with respect to 100 mass parts of polycarbonate resin (A). (Ii) the proportion of particles having a particle size of 1 μm or more and less than 2 μm, the proportion of particles having a particle size of 2 μm or more and less than 3 μm, and the proportion of particles having a particle size of 3 μm or more are 20 to 40%, respectively. Provided is a polycarbonate resin composition comprising 0.1 to 5 parts by mass of (iii) acrylic resin-based fine particles (B) having a particle diameter of 10 μm or more in a range. Is done.

  According to the second invention of the present invention, in the first invention, the acrylic resin-based fine particles (B) are 90 to 99% by mass of the non-crosslinkable acrylic monomer (B1) and the crosslinkable monomer (B2) 10 to 10. There is provided a polycarbonate resin composition characterized in that it is a copolymer fine particle from 1% by mass.

  According to the third invention of the present invention, there is provided a polycarbonate resin composition according to the first or second invention, wherein the acrylic resin fine particles (B) are polymethyl methacrylate fine particles. Is done.

  According to the fourth invention of the present invention, in any one of the first to third inventions, the ultraviolet absorbent (C) is further added in an amount of 0.05 to 1 mass with respect to 100 parts by mass of the polycarbonate resin (A). The polycarbonate resin composition characterized by containing a part is provided.

  According to the fifth aspect of the present invention, in any one of the first to fourth aspects, the organic sulfonic acid metal salt (D) is further added in an amount of 0.01 to 100 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). A polycarbonate resin composition containing 1 part by mass is provided.

  Moreover, according to the 6th invention of this invention, the molded article obtained from the polycarbonate resin composition of any one of the 1st-5th invention is provided.

  Furthermore, according to the seventh invention of the present invention, in the sixth invention, a molded product is provided in which the molded product is an illumination cover or a light diffusion plate.

  According to the polycarbonate resin composition of the present invention and a molded article comprising the polycarbonate resin composition, the polycarbonate resin composition is excellent in mechanical properties such as impact resistance, excellent in total light transmittance, light diffusibility, dispersibility, and excellent in moldability. And a molded product made of the same can be obtained.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples and the like, and is within the scope of the present invention. Any change can be made.

[1. Overview]
The polycarbonate resin composition of the present invention has an average particle diameter of 1 to 4 μm measured on a number basis in a range of 0.4 to 12 μm in diameter by (i) Coulter counter method with respect to 100 parts by mass of the polycarbonate resin (A). (Ii) The ratio of particles having a particle diameter of 1 μm or more and less than 2 μm, the ratio of particles having a particle diameter of 2 μm or more and less than 3 μm, and the ratio of particles having a particle diameter of 3 μm or more are in the range of 20 to 40%, And (iii) 0.1-5 mass parts of acrylic resin type microparticles | fine-particles (B) which do not contain a particle | grain with a particle size of 10 micrometers or more substantially are characterized by the above-mentioned.

[2. Polycarbonate resin (A)]
Examples of the polycarbonate resin (A) of the resin material used in the present invention include aromatic polycarbonate resins, aliphatic polycarbonate resins, and aromatic-aliphatic polycarbonate resins, preferably aromatic polycarbonate resins. A thermoplastic aromatic polycarbonate polymer or copolymer obtained by reacting an aromatic dihydroxy compound with phosgene or a diester of carbonic acid is used.

  Examples of the aromatic dihydroxy compound include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), tetramethylbisphenol A, α, α′-bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, Resorcinol, 4,4′-dihydroxydiphenyl and the like can be mentioned. Further, as a part of the dihydroxy compound, when the above-mentioned aromatic dihydroxy compound is combined with one or more tetraalkylphosphonium sulfonates, or a polymer or oligomer containing both terminal phenolic OH groups having a siloxane structure, A highly flame-retardant polycarbonate resin can be obtained.

  Preferred examples of the polycarbonate resin (A) used in the present invention include 2,2-bis (4-hydroxyphenyl) propane as a dihydroxy compound, or 2,2-bis (4-hydroxyphenyl) propane and other aromatic dihydroxy. The polycarbonate resin which used the compound together is mentioned. In the present invention, two or more polycarbonate resins may be used in combination as the component (A).

  The molecular weight of the polycarbonate resin (A) used in the present invention is a viscosity average molecular weight converted from a solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent, preferably 14,000 to 30,000, more preferably 18,000 to 29,000. When the viscosity average molecular weight is within this range, a resin composition can be obtained that gives a molded article having good moldability and high mechanical strength. The most preferable molecular weight range of the polycarbonate resin (A) is 22,000 to 28,000.

  The method for producing the polycarbonate resin is not particularly limited, and a polycarbonate resin produced by any of the phosgene method (interfacial polymerization method) and the melting method (transesterification method) can also be used. Moreover, it is also preferable to use the polycarbonate resin which performed the post-process which adjusts the amount of terminal OH groups to the polycarbonate resin manufactured by the melting method.

The polycarbonate resin in the present invention preferably contains a certain percentage or more of a polycarbonate resin having a structural viscosity index N in a predetermined range.
The structural viscosity index N is an index for evaluating the flow characteristics of a melt as described in detail in the document “Rheology for chemists” (Chemical Doujin, 1982, pp. 15-16). . Usually, the melting characteristics of polycarbonate resin can be expressed by the formula: γ = a · σ ^N. In the above formula, γ: shear rate, a: constant, σ: stress, N: structural viscosity index.

  In the above formula, when N = 1, Newtonian fluidity is shown, and the non-Newtonian fluidity increases as the value of N increases. That is, the flow characteristics of the melt are evaluated by the magnitude of the structural viscosity index N. In general, a polycarbonate resin having a large structural viscosity index N tends to have a high melt viscosity in a low shear region. For this reason, when a polycarbonate resin having a large structural viscosity index N is mixed with another polycarbonate resin, dripping at the time of combustion of the obtained polycarbonate resin composition can be suppressed, and flame retardancy can be improved. However, in order to maintain the moldability of the obtained polycarbonate resin composition in a favorable range, the structural viscosity index N of the polycarbonate resin is preferably not excessively large.

Therefore, the polycarbonate resin in the polycarbonate resin composition of the present invention has a structural viscosity index N of usually 1.2 or more, preferably 1.25 or more, more preferably 1.28 or more, and usually 1.8 or less. It is preferable to contain a polycarbonate resin of 1.7 or less, preferably an aromatic polycarbonate resin in a certain ratio or more.
The high structural viscosity index N means that the polycarbonate resin has a branched chain. By containing the polycarbonate resin having a high structural viscosity index N in this way, the polycarbonate resin composition of the present invention burns. The dripping at the time can be suppressed and the flame retardancy can be improved.

The structural viscosity index N can also be expressed by Log η _a = [(1-N) / N] × Log γ + C, which is derived from the above equation, as described in, for example, JP-A-2005-232442. Is possible. In the above formula, N: structural viscosity index, γ: shear rate, C: constant, η _a : apparent viscosity. As can be seen from this equation, the N value can also be evaluated from γ and ηa in _a low shear region in which the viscosity behavior is greatly different. For example, the N value can be determined from η _a at γ = 12.16 sec ⁻¹ and γ = 24.32 sec ⁻¹ .

  An aromatic polycarbonate resin having a structural viscosity index N of 1.2 or more is obtained by a melting method (transesterification method) as described in JP-A-8-259687 and JP-A-8-245782, for example. When reacting an aromatic dihydroxy compound and a carbonic acid diester, an aromatic polycarbonate resin having a high structural viscosity index and excellent hydrolytic stability can be obtained without adding a branching agent by selecting catalyst conditions or production conditions. be able to.

An aromatic polycarbonate resin having a structural viscosity index N of 1.2 or more can also be produced by a method using a branching agent when produced by a phosgene method or a melting method (a transesterification method) according to a conventional method. .
Specific examples of the branching agent include phloroglucin, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptene-2, 4,6-dimethyl-2,4,6-tris (4-hydroxy). Phenyl) heptane, 2,6-dimethyl-2,4,6-tris (4-hydroxyphenylheptene-3,1,3,5-tris (4-hydroxyphenyl) ethane and the like, and 3,3-bis (4-hydroxyaryl) oxindole (= isatin bisphenol), 5-chlorisatin bisphenol, 5,7-dichloroisatin bisphenol, 5-bromoisatin bisphenol and the like.
The amount used is in the range of 0.01 to 10 mol%, particularly preferably in the range of 0.1 to 3 mol%, based on the aromatic dihydroxy compound.

  The molecular weight of the aromatic polycarbonate resin having a structural viscosity index N of 1.2 or more is a viscosity average molecular weight in the range of 16,000 to 30,000 converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. Is preferred.

In the polycarbonate resin composition of the present invention, the polycarbonate resin is a polycarbonate resin in which the structural viscosity index N described above is in a predetermined range (hereinafter, this polycarbonate resin may be referred to as “predetermined N polycarbonate resin”). In general, it is desirable to contain 20% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more. By combining with a predetermined N polycarbonate resin in this way, the torque during extrusion is not increased more than necessary, so that the productivity is hardly lowered, and the deterioration of the acrylic fine particles due to shearing heat generation can be suppressed, so that diffusibility is achieved. It is also difficult to invite a decrease in. That is, the moldability, productivity, and diffusibility can be remarkably exhibited.
In addition, there is no restriction | limiting in the upper limit of content of predetermined N polycarbonate resin in polycarbonate resin, Usually, it is 100 mass% or less, Preferably it is 90 mass% or less, More preferably, it is 85 mass% or less.
Moreover, 1 type may be used for predetermined N polycarbonate resin, and it may use 2 or more types together by arbitrary combinations and a ratio.

  Further, the polycarbonate resin may include a polycarbonate resin having a structural viscosity index N outside the above predetermined range, in addition to the above predetermined N polycarbonate resin. Although there is no restriction | limiting in the kind, A linear polycarbonate resin is preferable especially. By combining the predetermined N polycarbonate resin and the linear polycarbonate resin, there is an advantage that it is easy to balance the flame retardancy (anti-dripping property) and moldability (fluidity) of the obtained polycarbonate resin composition. From this viewpoint, it is particularly preferable that the polycarbonate resin is composed of a predetermined N polycarbonate resin and a linear polycarbonate resin. In addition, the structural viscosity index N of this linear polycarbonate resin is usually about 1-1.15.

  When the polycarbonate resin contains a linear polycarbonate resin, the proportion of the linear polycarbonate resin in the polycarbonate resin is usually 80% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, Usually, it is more than 0% by mass, preferably 10% by mass or more, more preferably 15% by mass or more. By setting the content of the linear polycarbonate resin in the polycarbonate resin within the above range, it is easy to obtain good dispersibility of acrylic resin fine particles and other additives, and a polycarbonate resin excellent in flame retardancy and moldability is obtained. The advantage of being easily obtained is obtained.

  The polycarbonate resin is a polycarbonate resin alone (the polycarbonate resin alone is not limited to an embodiment containing only one type of polycarbonate resin, and is used in a sense including an embodiment containing a plurality of types of polycarbonate resins having different monomer compositions and molecular weights, for example. .), Or an alloy (mixture) of a polycarbonate resin and another thermoplastic resin may be used in combination. Further, for example, for the purpose of further improving flame retardancy and impact resistance, a polycarbonate resin is copolymerized with an oligomer or polymer having a siloxane structure; for the purpose of further improving thermal oxidation stability and flame retardancy A monomer, oligomer or polymer having a copolymer; a monomer, oligomer or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermal oxidation stability; A copolymer with an oligomer or polymer having an olefin structure; a copolymer with a polyester resin oligomer or polymer for the purpose of improving chemical resistance; Good.

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

Further, the polycarbonate resin may be not only a virgin raw material but also a polycarbonate resin regenerated from a used product (so-called material-recycled polycarbonate resin). Examples of the used products include: optical recording media such as optical disks; light guide plates; vehicle window glass, vehicle headlamp lenses, windshields and other vehicle transparent members; water bottles and other containers; eyeglass lenses; Examples include architectural members such as glass windows and corrugated sheets. Also, non-conforming products, pulverized products obtained from sprues, runners, etc., or pellets obtained by melting them can be used.
However, the regenerated polycarbonate resin is preferably 80% by mass or less, more preferably 50% by mass or less, among the polycarbonate resins contained in the polycarbonate resin composition of the present invention. Recycled polycarbonate resin is likely to have undergone deterioration such as heat deterioration and aging deterioration, so when such polycarbonate resin is used more than the above range, hue and mechanical properties can be reduced. It is because there is sex.

[3. Acrylic resin-based fine particles (B)]
The polycarbonate resin composition of the present invention contains 0.1 to 5 parts by mass of acrylic resin-based fine particles (B) satisfying specific particle sizes and particle size distributions (i) to (iii) below.
(I) The average particle diameter measured on the basis of the number in the range of 0.4 to 12 μm in diameter by the Coulter counter method is 1 to 4 μm,
(Ii) The ratio of particles having a particle diameter of 1 μm or more and less than 2 μm, the ratio of particles having a particle diameter of 2 μm or more and less than 3 μm, and the ratio of particles having a particle diameter of 3 μm or more are in the range of 20 to 40%, respectively ( iii) substantially does not contain particles having a particle size of 10 μm or more.
By blending such acrylic resin-based fine particles in such an amount, the excellent light diffusibility and light transmittance of the polycarbonate resin composition of the present invention can be achieved.

  As the acrylic resin-based fine particles (B), any polymer or copolymer using an acrylic monomer that satisfies the above characteristics (i) to (iii) can be used. Examples of the polymer include polymethyl methacrylate, polymethyl acrylate, polyethyl acrylate, polycyclohexyl methacrylate, and copolymers thereof.

Particularly preferred as the acrylic resin resin fine particles (B) used in the present invention is an acrylic resin produced by a non-crosslinkable acrylic monomer (B1) and a crosslinkable monomer (B2), preferably by suspension polymerization. System fine particles.
As the non-crosslinkable acrylic monomer, an acrylic monomer alone or a combination of acrylic monomers is used. As acrylic monomers, acrylic acid esters such as methyl acrylate, n-butyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethyl-hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate Preferred examples thereof include methacrylic acid esters, and these can be used alone or in combination of two or more. Of these, methyl methacrylate is preferably used.
The monomer may be added with a monomer copolymerizable with a (meth) acrylic acid ester monomer. Examples of such a monomer include styrene, α-methylstyrene, Examples thereof include monomers having a vinyl group such as vinyl acetate.

  On the other hand, as the crosslinkable monomer, a compound having two or more unsaturated bonds in the molecule is preferably used. For example, trimethylolpropane tri (meth) acrylate, allyl methacrylate, triallyl cyanurate, triallyl isocyanate, ethylene glycol dimethacrylate, propylene glycol diallyl ether, divinylbenzene, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, etc. Can be mentioned. Of these, trimethylolpropane tri (meth) acrylate is preferable.

  The acrylic resin fine particles (B) can be produced by suspension polymerization of the non-crosslinkable acrylic monomer (B1) and the crosslinkable monomer (B2). For example, the polymerization can be carried out by suspending both monomers using polyvinyl alcohol as a dispersant, followed by filtration, washing, sieving and drying. The proportions of both monomers used are 90 to 99 mass% of the non-crosslinkable acrylic monomer (B1) and 10 to 1 mass% of the crosslinkable monomer (B2). If the amount of the crosslinkable monomer is too small, the dispersibility of the obtained bead-shaped crosslinked acrylic resin in the polycarbonate resin is poor, and conversely, if the blending ratio of the crosslinkable monomer (B2) is large, an acrylic resin type Since the fine particles (B) become too hard and impact strength decreases, it is not preferable.

As described above, the acrylic resin-based fine particles (B) are (i) those having an average particle size of 1 to 4 μm, and (ii) the proportion of particles having a particle size of 1 μm or more and less than 2 μm, and the particle size is The ratio of particles having a particle diameter of 2 μm or more and less than 3 μm and the ratio of particles having a particle diameter of 3 μm or more are in the range of 20 to 40%, respectively, and (iii) those having substantially no particles having a particle diameter of 10 μm or more are used. To do.
In the present invention, the acrylic resin fine particles (B) are those having an average particle size of 1 to 4 μm smaller than that of an average particle size of 6 to 10 μm that has been used normally, and further its particle size distribution. Contrary to the conventional common sense that monodispersion has been said to be good, as described above, a material having a broad particle size distribution is used.

In the present invention, the particle size and particle size distribution are measured on a number basis by the Coulter counter method. In the Cole Counter method, an electrolyte in which sample particles are suspended is passed through pores (apertures), and changes in voltage pulses generated in proportion to the volume of the particles at that time are read to quantify the particle diameter. In addition, the volume distribution histogram of the sample particles can be obtained by measuring the voltage pulse height one by one. Such particle size or particle size distribution measurement by the call counter method is most frequently used as a particle size distribution measuring apparatus.
In the present invention, the particle diameter measurement of the acrylic resin-based fine particles (B) eliminates the influence of extremely small fine particles and extremely large maximal particles, and obtains highly reliable and highly reproducible data. It is defined by measuring in a range of ˜12 μm. The average particle diameter is an average particle diameter based on the number.
In addition, the average particle diameter in this invention says D50 measured with a laser diffraction type particle size distribution measuring apparatus, and measured using Shimadzu Corporation "laser diffraction type particle size distribution measuring apparatus SALD-2100".

  The acrylic resin-based fine particles (B) used in the present invention have an average particle diameter of 1 to 4 μm, and if the average particle diameter is not within this range, the light diffusivity and the degree of dispersion are reduced. The average particle size is preferably 1 to 3 μm, more preferably 1.5 to 3 μm.

  In addition, the acrylic resin-based fine particles (B) may be referred to as a “number reference frequency” in which the ratio of particles in the range of 1 μm or more and less than 2 μm (%, the total number in the range of 0.4 to 12 μm in diameter is 100%. ) Is 20 to 40%, the proportion of particles having a particle size of 2 μm or more and less than 3 μm is 20 to 40%, and the proportion of particles having a particle size of 3 μm or more is 20 to 40%. You need to be in range. Thus, by making the number standard frequency in each particle size into the range of 20 to 40%, the light diffusion effect and the transmittance can be further improved, and the impact resistance can be improved.

Furthermore, the acrylic resin-based fine particles (B) are characterized by containing substantially no particles having a particle size of 10 μm or more, preferably 8 μm or more. When the particle size contains 10 μm or more, impact resistance, which is a particularly necessary characteristic for a lighting member, is lowered.
In addition, “substantially does not contain” in the case of substantially not containing particles having a particle size of 10 μm or more includes the case where particles having a prescribed particle size are not completely contained, of course, the above particle size distribution. It means that it is not detected by the measuring device.

  Content of acrylic resin type microparticles | fine-particles (B) is 0.1-5 mass parts with respect to 100 mass parts of polycarbonate resin (A), Preferably it is 0.1-2 mass parts, More preferably, 0.3- 1.5 parts by mass. When the usage rate of the acrylic resin fine particles (B) is less than 0.1 parts by mass, the effect of improving the transmittance and light diffusibility of the polycarbonate resin cannot be sufficiently obtained, and the usage rate exceeds 5 parts by mass. Is not preferable because the impact resistance and the like of the polycarbonate resin tend to decrease.

  Then, the average particle size is 1 to 4 μm, the number reference frequency in each particle size range is 20 to 40%, and the material substantially not containing 10 μm or more is 0.1 to 0.1%. By blending 5 parts by mass, it is possible to obtain a composition that is excellent in mechanical properties such as impact resistance, improves the total light transmittance, light diffusibility, and dispersibility, and has excellent moldability.

A method for producing acrylic resin-based fine particles having such a particle diameter is known and is not particularly limited, but it is also preferable to directly polymerize and produce particles by emulsion polymerization or suspension polymerization. . When the acrylic resin-based fine particles are produced directly by polymerization, the particle diameter can be controlled by the polymerization conditions. For example, a polymer having a broad distribution can be obtained by using a homogenizer so that the particle diameter is a predetermined one and the particle diameter distribution is not loaded with an excessive shearing force.
In addition, the acrylic resin obtained in the solid state is pulverized by a pulverizer such as a jet airflow pulverizer, mechanical collision pulverizer, roll mill, hammer mill, impeller breaker, etc. The particle size of the particles may be controlled by being introduced into a classification device such as a device for classification.
Moreover, it can also select and use from the various acrylic resin particle | grains known commercially.

[4. UV absorber (C)]
It is preferable to mix | blend a ultraviolet absorber (C) with the composition of this invention. Examples of the ultraviolet absorber include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide; organics such as benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylate compounds, triazine compounds, oxanilide compounds, malonic ester compounds, hindered amine compounds, etc. Examples include ultraviolet absorbers. Of these, organic ultraviolet absorbers are preferred, and benzotriazole compounds are more preferred. By selecting the organic ultraviolet absorber, the polycarbonate resin composition of the present invention has good transparency and mechanical properties.

  Specific examples of the benzotriazole compound include, for example, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl). ) Phenyl] -benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butyl-phenyl) -benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5 ′) -Methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butyl-phenyl) -5-chlorobenzotriazole), 2- (2'-hydroxy-3 ', 5'-di-tert-amyl) -benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2N-benzotriazol-2-yl) phenol] and the like, among others, 2- (2′- Hydroxy-5'-tert-octylphenyl) benzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2N-benzotriazol-2-yl) phenol] And 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole is particularly preferable.

  Specific examples of such benzotriazole compounds include “Seesorb 701”, “Seesorb 702”, “Seesorb 703”, “Seesorb 704”, and “Seesorb 705” manufactured by Sipro Kasei Co., Ltd. (trade names, the same applies hereinafter). , “Seasorb 709”, “Biosorb 520”, “Biosorb 580”, “Biosorb 582”, “Biosorb 583” manufactured by Kyodo Yakuhin Co., Ltd. “UV5411”, “LA-32”, “LA-38”, “LA-36”, “LA-34”, “LA-31”, manufactured by Adeka Corporation, “Tinuvin P”, “Cinuvin 234” manufactured by Ciba Specialty Chemicals , "Tinubin 326", "Tinubin 327", "Tinubin 328 Etc. The.

  The content of the ultraviolet absorber (C) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the polycarbonate resin (A), and the upper limit is preferably Is 1 part by mass or less, more preferably 0.5 part by mass or less. If the content of the UV absorber is below the lower limit of the above range, the effect of improving the weather resistance may be insufficient, and if the content of the UV absorber exceeds the upper limit of the above range, the mold Debogit etc. may occur and cause mold contamination. In addition, 1 type may contain the ultraviolet absorber and 2 or more types may contain it by arbitrary combinations and a ratio.

[5. Organic sulfonic acid metal salt (D)]
The composition of the present invention preferably contains an organic sulfonic acid metal salt (D).
Examples of organic sulfonic acid metal salts include aliphatic sulfonic acid metal salts, aromatic sulfonic acid metal salts, and the like. Among them, aromatic sulfone sulfonic acid metal salts and perfluoroalkane sulfonic acid metal salts are preferable, and perfluorocarbon metal salts are particularly preferable. Alkanesulfonic acid metal salts are preferred.
The metal of the organic sulfonic acid metal salt is not particularly limited but preferably includes alkali metals such as sodium, lithium, potassium, rubidium and cesium, and alkaline earth metals such as beryllium, magnesium, calcium, strontium and barium. It is done. Of these, potassium is preferred from the viewpoints of flame retardancy and hydrolysis resistance. These organic sulfonic acid metal salts may be used in combination of two or more.

The aromatic sulfonesulfonic acid metal salt is preferably an aromatic sulfonesulfonic acid alkali metal salt, an aromatic sulfonesulfonic acid alkaline earth metal salt, or the like. The acid alkaline earth metal salt may be a polymer.
Specific examples of the aromatic sulfonesulfonic acid metal salt include sodium salt of diphenylsulfone-3-sulfonic acid, potassium salt of diphenylsulfone-3-sulfonic acid, sodium 4 / 4'-dibromodiphenyl-sulfone-3-sulfone Salt, potassium salt of 4,4′-dibromodiphenylsulfone-3-sulfone, calcium salt of 4-chloro-4′-nitrodiphenylsulfone-3-sulfonic acid, diphenylsulfone-3,3′-disulfonic acid di Examples thereof include sodium salts and dipotassium salts of diphenylsulfone-3,3′-disulfonic acid.

The perfluoroalkanesulfonic acid metal salt is preferably an alkali metal salt of perfluoroalkanesulfonic acid, an alkaline earth metal salt of perfluoroalkanesulfonic acid, or the like, more preferably a perfluoroalkane having 4 to 8 carbon atoms. Examples include sulfonic acid alkali metal salts having an alkane group and sulfonic acid alkaline earth metal salts having a C 4-8 perfluoroalkane group.
Specific examples of the perfluoroalkanesulfonic acid metal salt include sodium perfluorobutanesulfonate, potassium perfluorobutanesulfonate, sodium perfluoromethylbutanesulfonate, potassium perfluoromethylbutanesulfonate, sodium perfluorooctanesulfonate, Examples include potassium perfluorooctane sulfonate and tetraethylammonium salt of perfluorobutane sulfonic acid.
Among these, potassium perfluorobutanesulfonate is particularly preferable.

  The content of the organic sulfonic acid metal salt is preferably 0.01 to 1 part by weight, more preferably 0.05 to 0.5 part by weight, and particularly preferably 0.1 to 0 part with respect to 100 parts by weight of the polycarbonate resin (A). 3 parts by mass. When the content is less than 0.01 parts by mass, sufficient flame retardancy is difficult to obtain, and when it exceeds 1 part by mass, the thermal stability and hydrolysis resistance are likely to be lowered.

[6. Other additives]
The polycarbonate resin composition of the present invention may further contain various additives as long as the effects of the present invention are not impaired. Such additives include heat stabilizers, antioxidants, mold release agents, flame retardants, dyes and pigments, fluorescent whitening agents, anti-dripping agents, antistatic agents, antifogging agents, lubricants, antiblocking agents, flow Examples include property improvers, plasticizers, dispersants, and antibacterial agents.

-Heat stabilizer As a heat stabilizer, a phosphorus compound is mentioned, for example. Any known phosphorous compound can be used. Specific examples include phosphorus oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphoric acid Examples thereof include phosphates of Group 1 or Group 10 metals such as potassium, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds.

  Among them, triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, Dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) ) Organic phosphites such as octyl phosphite are preferred.

  The content of the heat stabilizer is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, more preferably 0.03 part by mass or more, based on 100 parts by mass of the polycarbonate resin. It is not more than part by mass, preferably not more than 0.7 part by mass, more preferably not more than 0.5 part by mass. If the amount of the heat stabilizer is too small, the heat stabilization effect may be insufficient. If the amount of the heat stabilizer is too large, the effect may reach a peak and may not be economical.

-Antioxidant As an antioxidant, a hindered phenolic antioxidant is mentioned, for example. Specific examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6-diylbis [3- (3,5-di-) tert-butyl-4-hydroxyphenylpropionamide), 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl ] Methyl] phosphoate, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(mesi Tylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4- Hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert- Butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis ( Octylthio) -1,3,5-triazin-2-ylamino) phenol and the like.

  Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate preferable.

  The content of the antioxidant is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 1 part by mass or less, preferably 0.5 part by mass with respect to 100 parts by mass of the polycarbonate resin. Or less. When the content of the antioxidant is less than or equal to the lower limit of the range, the effect as an antioxidant may be insufficient, and when the content of the antioxidant exceeds the upper limit of the range, There is a possibility that the effect reaches its peak and is not economical.

-Release agent Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane silicone oils. It is done.

  Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acid. Here, the aliphatic carboxylic acid includes alicyclic carboxylic acid. Among these, preferable aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms are more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, mellicic acid, tetrariacontanoic acid, montanic acid, adipine Examples include acids and azelaic acid.

  As aliphatic carboxylic acid in ester of aliphatic carboxylic acid and alcohol, the same thing as the said aliphatic carboxylic acid can be used, for example. On the other hand, examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monovalent or polyvalent saturated alcohol having 30 or less carbon atoms is preferable, and an aliphatic or alicyclic saturated monohydric alcohol or aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferable.

  Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. Is mentioned.

  Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate Examples thereof include rate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

Examples of the aliphatic hydrocarbon having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomer having 3 to 12 carbon atoms. Here, the aliphatic hydrocarbon includes alicyclic hydrocarbons.
Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable.
The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.

  The content of the release agent is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass or less with respect to 100 parts by mass of the polycarbonate resin. It is. When the content of the release agent is not more than the lower limit of the above range, the effect of releasability may not be sufficient, and when the content of the release agent exceeds the upper limit of the above range, hydrolysis resistance And mold contamination during injection molding may occur.

-Anti-dripping agent It is preferable that the polycarbonate resin composition of this invention contains 0.01-1 mass part of fluororesins as an anti-dripping agent with respect to 100 mass parts of polycarbonate resin. By containing the fluororesin in this manner, the melting characteristics of the resin composition can be improved, and specifically, the dripping prevention property at the time of combustion can be improved.

  If the content of the fluororesin is less than 0.01 parts by mass, the effect of improving the flame retardancy due to the fluororesin tends to be insufficient, and if it exceeds 1 part by mass, a molded product obtained by molding a thermoplastic resin composition. The appearance defect and the mechanical strength are likely to decrease. The lower limit of the content is more preferably 0.05 parts by mass or more, further preferably 0.1 parts by mass or more, particularly preferably 0.2 parts by mass or more, and the upper limit of the content is more preferably 0. .75 parts by mass or less, more preferably 0.6 parts by mass or less, and particularly preferably 0.5 parts by mass or less.

Of these, fluoroolefin resins are preferred as the fluororesin. The fluoroolefin resin is usually a polymer or copolymer containing a fluoroethylene structure, and specific examples include difluoroethylene resin, tetrafluoroethylene resin, tetrafluoroethylene / hexafluoropropylene copolymer resin, Of these, tetrafluoroethylene resin is preferred.
Moreover, as this fluororesin, what has a fibril formation ability is preferable, and specifically, the fluoro olefin resin which has a fibril formation ability is mentioned. Thus, it has the tendency to improve dripping prevention property at the time of combustion by having fibril formation ability.

  Examples of the fluoroolefin resin having a fibril-forming ability include “Teflon (registered trademark) 6J” manufactured by Mitsui DuPont Fluorochemical Co., Ltd., “Polyflon (registered trademark) F201L” manufactured by Daikin Chemical Industries, Ltd. "," Polyflon (registered trademark) FA500 "and the like. Furthermore, as commercially available products of aqueous dispersions of fluoroolefin resins, for example, “Teflon (registered trademark) 30J”, “Teflon (registered trademark) 31-JR” manufactured by Mitsui DuPont Fluorochemical Co., Ltd., “Fluon ( Registered trademark) D-1 "and the like.

  Furthermore, an organic polymer-coated fluoroolefin resin can also be suitably used. By using the organic polymer-coated fluoroolefin resin, the dispersibility is improved, the surface appearance of the molded product is improved, and the surface foreign matter can be suppressed. The organic polymer-coated fluoroolefin resin can be produced by various known methods. For example, (1) a polyfluoroethylene particle aqueous dispersion and an organic polymer particle aqueous dispersion are mixed and powdered by coagulation or spray drying. (2) A method of polymerizing a monomer constituting an organic polymer in the presence of an aqueous dispersion of polyfluoroethylene particles, and then pulverizing or producing the powder by solidification or spray drying. 3) After emulsion polymerization of a monomer having an ethylenically unsaturated bond in a dispersion obtained by mixing an aqueous dispersion of polyfluoroethylene particles and an aqueous dispersion of organic polymer particles, a powder is obtained by coagulation or spray drying. And the like, and the like.

The organic polymer for coating the fluoroolefin resin is not particularly limited, and specific examples of monomers for producing such an organic polymer include styrene, α-methylstyrene, p. -Methylstyrene, o-methylstyrene, tert-butylstyrene, o-ethylstyrene, p-chlorostyrene, o-chlorostyrene, 2,4-dichlorostyrene, p-methoxystyrene, o-methoxystyrene, 2,4- Aromatic vinyl monomers such as dimethylstyrene;
Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, (Meth) acrylic acid ester monomers such as tridecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate;

Vinyl cyanide monomers such as acrylonitrile and methacrylonitrile;
Α, β-unsaturated carboxylic acids such as maleic anhydride; maleimide monomers such as N-phenylmaleimide, N-methylmaleimide, N-cyclohexylmaleimide;
Glycidyl group-containing monomers such as glycidyl methacrylate;
Vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether; vinyl carboxylate monomers such as vinyl acetate and vinyl butyrate;
Olefinic monomers such as ethylene, propylene, isobutylene;
Examples thereof include diene monomers such as butadiene, isoprene and dimethylbutadiene. In addition, these monomers can be used individually or in mixture of 2 or more types.

  Among them, as a monomer for producing an organic polymer covering a fluoroolefin resin, those having a high affinity with an aromatic polycarbonate resin are preferable from the viewpoint of dispersibility when blended with an aromatic polycarbonate resin. An aromatic vinyl monomer, a (meth) acrylic acid ester monomer, and a vinyl cyanide monomer are more preferable.

  The content ratio of the fluoroolefin resin in the organic polymer-coated fluoroolefin resin is usually 30% by mass or more, preferably 35% by mass or more, more preferably 40% by mass or more, and particularly preferably 45% by mass or more. Usually, it is 95 mass% or less, Preferably it is 90 mass% or less, More preferably, it is 80 mass% or less, Most preferably, it is 75 mass% or less. It is preferable that the content ratio of the fluoroolefin resin in the organic polymer-coated fluoroolefin resin is in the above-described range because the balance between the flame retardancy and the appearance of the molded product tends to be excellent.

As such an organic polymer-coated fluoroolefin resin, specifically, “Metabrene (registered trademark) A-3800” manufactured by Mitsubishi Rayon Co., Ltd., “Blendex (registered trademark) 449” manufactured by GE Specialty Chemical Co., Ltd., PIC Company "Poly TS AD001" manufactured by the company etc. are mentioned.
In addition, 1 type may contain fluorine-type resin, and 2 or more types may contain it by arbitrary combinations and a ratio.

[7. Production method of polycarbonate resin composition]
There is no limitation on the method for producing the polycarbonate resin composition of the present invention, and a known method for producing a polycarbonate resin composition can be widely adopted. The polycarbonate resin and the polyorganosiloxane particles, and other components blended as necessary, For example, after mixing in advance using various mixers such as a tumbler and a Henschel mixer, a method of melt kneading with a mixer such as a Banbury mixer, roll, Brabender, single-screw kneading extruder, twin-screw kneading extruder, kneader, etc. It is done. The temperature for melt kneading is not particularly limited, but is usually in the range of 240 to 320 ° C.

[8. Molding]
The polycarbonate resin composition of the present invention can be produced by molding pelletized pellets by various molding methods. Further, the resin melt-kneaded by an extruder can be directly made into a sheet, a film, a profile extrusion-molded product, a blow-molded product, an injection-molded product or the like without going through pellets.
Examples of molding methods include injection molding methods, ultra-high speed injection molding methods, injection compression molding methods, two-color molding methods, hollow molding methods such as gas assist, molding methods using heat insulating molds, and rapid heating molds. Molding method used, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding Law. A molding method using a hot runner method can also be used. There is no limitation on the shape, pattern, color, size, etc. of the molded product, and it may be set arbitrarily according to the application of the molded product.

  Preferred molded articles obtained by molding the composition of the present invention include various lighting covers, lighting signs, transmissive screens, various displays, light diffusing sheets and light diffusing plates for liquid crystal display devices, and particularly for liquid crystal display devices. The light diffusing sheet and the light diffusing plate can be suitably used particularly as a diffusing plate for large liquid crystal televisions.

  Examples of lighting covers include fluorescent lamps and incandescent light bulb covers and lamp shades, bathroom lights, chandeliers, stands, brackets, lanterns, ceiling lights, pendant lights, garage lights, eaves lights, gatepost lights, and porch lights. , Garden lights, entrance lights, step lights, stair lights, guide lights, crime prevention lights, downlights, base lights, electric signs, sign lights, and other vehicle lamps such as automobiles and motorcycles It can be suitably used for a cover or the like. In particular, it can be suitably used for a lighting fixture that uses a light source that emits less heat, such as an LED or an organic EL.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

(Examples 1-11, Comparative Examples 1-7)
[Polycarbonate resin (A)]
The polycarbonate resins (A1) and (A2) shown in Table 1 below were used as the polycarbonate resin.

[Acrylic resin fine particles (B)]
Acrylic resin-based particles (B1) to (B5) shown in Table 2 below were prepared.

[Ultraviolet absorber (C) and other additive components (D) to (E)]
As the ultraviolet absorber (C) and other additive components (D) to (E), those described in Table 3 below were used.

[Production of resin composition pellets]
The above components (A) to (E) were blended in the proportions (mass%) shown in Table 4 and Table 5, mixed for 20 minutes with a tumbler, and then manufactured by Nippon Steel Works Co., Ltd. equipped with 1 vent. Supplied to a shaft extruder (TEX30HSST), kneaded under the conditions of a screw speed of 200 rpm, a discharge rate of 20 kg / hour, and a barrel temperature of 280 ° C., the molten resin extruded into a strand is quenched in a water tank, and then used with a pelletizer Pelletized polycarbonate resin composition pellets were obtained.

[Preparation of test piece]
After drying the pellets obtained by the above-described production method at 120 ° C. for 5 hours, using a SYCAP SG75M2 type injection molding machine manufactured by Sumitomo Heavy Industries, the cylinder temperature is 280 ° C., the mold temperature is 80 ° C., and the molding cycle is 45 Injection molding was performed under the conditions of seconds, and a three-stage plate (3, 2, 1 mm thickness) and an ISO multipurpose test piece (3 mm) were molded.

Using these test pieces, total light transmittance, diffusivity, dispersity, and impact resistance were evaluated.
Each evaluation method is as follows.

[Fluidity evaluation]
After the pellets obtained as described above were dried at 120 ° C. for 4 hours or longer, JIS K7210
Using a high-load flow tester according to the method described in Appendix C, the outflow Q value of the composition per unit time under the conditions of 280 ° C. and a load of 160 kgf / cm ² (unit: × 10 ⁻² cm ³ / Sec) was measured to evaluate the fluidity. An orifice having a diameter of 1 mm and a length of 10 mm was used. It shows that it is excellent in fluidity | liquidity, so that Q value is high.

[Impact resistance evaluation]
Based on ISO179, the ISO multipurpose test piece (3 mm thickness) produced above was notched, and the Charpy impact strength with notch (unit: kJ / m ² ) was measured at 23 ° C. In Tables 4 and 5, it is expressed as “Charpy impact”.

[Flame retardance evaluation]
For each resin composition obtained in the examples and comparative examples, using an injection molding machine J50 manufactured by Nippon Steel Works, injection molding was performed under the conditions of a set temperature of 280 ° C. and a mold temperature of 80 ° C., a length of 127 mm, Molded articles having a width of 12.7 mm, a thickness of 1.2 mm, and 1.5 mm were obtained as test pieces. About the obtained test piece, the vertical combustion test based on UL94 was done, the flammability result was set to V-0, V-1, V-2 from the favorable order, and the thing outside a specification was classified into NG.

[Dispersity]
Using the above-mentioned three-stage plate (3, 2, 1 mm thick) as a test piece, using GP-5 GONIOPHOTOMETER manufactured by MURAKAMI COLOR RESEARCH LABORATORY, Incident light: 0 °, turn angle: 0 °, light receiving range: 0 ° to The luminance with a thickness of 1 mm was measured under the conditions of 90 °, the light beam stop: 2.0, and the light receiving stop: 3.0, and the angle at which the luminance was reduced to half with respect to the 0 ° luminance was determined as the degree of dispersion (°). The higher the degree of dispersion, the higher the light diffusibility, and it is preferable because it has the effect of further diffusing the light from the light source, maintaining the illuminance in a wider range, and lowering the visibility of the light source. In Tables 4 and 5, it is expressed as “dispersion degree”.

[Total light transmittance]
According to JIS K-7105, the total light transmittance (unit "%") of 1 mm thickness was measured with a NDH-2000 type turbidimeter manufactured by Nippon Denshoku Industries Co., Ltd. for the 1 mm thickness part of the above-mentioned three-stage plate.

[L value]
According to JIS K7105, a 1 mm thick portion of the three-stage plate was measured by a reflection method using a SE2000 type spectrocolorimeter manufactured by Nippon Denshoku Industries Co., Ltd.

[Moisture and heat resistance]
Using a pressure cooker tester (HAISTEST, MODEL PC-SIII, manufactured by Hirayama Seisakusho Co., Ltd.), the test piece was treated in a steam atmosphere at 121 ° C., a pressure of 2 kg / cm ² , and a humidity of 100% for 100 hours. The presence or absence was observed as an index of hydrolysis resistance.
The above evaluation results are shown in Tables 4 and 5.

The difference in the L value becomes remarkable in the case of a 1 mm-thick test piece. From Examples 1 to 11 shown in Table 4, acrylic resin-based fine particles satisfying the particle size and particle size distribution of the present invention ( It can be seen that the polycarbonate resin composition containing a predetermined amount of B1) is excellent in total light transmittance and dispersion, and has impact resistance.
On the other hand, the polycarbonate resin composition of the comparative example which mix | blended the acrylic resin type microparticles | fine-particles (B2-B5) which does not satisfy the particle size and particle size distribution of this invention, or contained acrylic resin type microparticles | fine-particles (B1) exceeding predetermined amount. It can be seen that the product is inferior in total light transmittance and dispersity, and inferior in impact resistance.
Therefore, from the above Examples and Comparative Examples, it was confirmed that the effects that the total light transmittance and the degree of dispersion were excellent and the impact resistance was also excellent were obtained for the first time by the configuration of the present invention.

  According to the polycarbonate resin composition of the present invention, molding materials having excellent mechanical properties such as impact resistance, total light transmittance, light diffusivity, dispersity, and excellent moldability can be obtained. It can be used in a wide range of fields such as lighting covers, lighting signs, transmissive screens, various displays, light diffusing sheets and light diffusing plates for liquid crystal display devices, and has very high industrial applicability.

Claims (7)

  For 100 parts by mass of the polycarbonate resin (A), (i) the average particle size measured on a number basis in the range of 0.4 to 12 μm in diameter by the Coulter counter method is 1 to 4 μm, and (ii) the particle size is 1 μm or more. The proportion of particles less than 2 μm, the proportion of particles having a particle size of 2 μm or more and less than 3 μm, and the proportion of particles having a particle size of 3 μm or more are in the range of 20 to 40%, respectively, and (iii) the particle size is 10 μm or more A polycarbonate resin composition characterized by containing 0.1 to 5 parts by mass of acrylic resin-based fine particles (B) substantially free of the above particles.   The acrylic resin-based fine particles (B) are copolymer fine particles composed of 90 to 99% by mass of a non-crosslinkable acrylic monomer (B1) and 10 to 1% by mass of a crosslinkable monomer (B2). The polycarbonate resin composition described in 1.   The polycarbonate resin composition according to claim 1 or 2, wherein the acrylic resin-based fine particles (B) are polymethyl methacrylate-based fine particles.   Furthermore, 0.05-1 mass part of ultraviolet absorbers (C) are contained with respect to 100 mass parts of polycarbonate resin (A), The polycarbonate resin composition in any one of Claims 1-3 characterized by the above-mentioned.   Furthermore, 0.01-1 mass part of organic sulfonic-acid metal salt (D) is contained with respect to 100 mass parts of polycarbonate resin (A), The polycarbonate resin composition in any one of Claims 1-4 characterized by the above-mentioned. object.   The molded article obtained from the polycarbonate resin composition in any one of Claims 1-6.   The molded article according to claim 6, wherein the molded article is a lighting cover or a light diffusion plate.