JP2009007508A - Light-diffusible thermoplastic resin composition and light-plate comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which has not only high optical performances such as light diffusibility and brightness but also a high mechanical strength capable of resisting to the thinning of a light-diffusible plate, and to provide a light-diffusible plate. <P>SOLUTION: This light-diffusible thermoplastic resin composition is characterized by comprising 100 pts.wt. of a resin component comprising 0.1 to 7 wt.% of polycaprolactone (A) and 93 to 99.9 wt.% of a transparent thermoplastic resin (B) except the polycaprolactone, 0.1 to 1.5 pts.wt. of silicone rubber particles (C) having an average particle size of 0.5-10 μm and a skeleton comprising difunctional siloxane units and trifunctional siloxane units and having alkyl groups on the surface, and 0.03 to 1 pt.wt. of a luminous agent (D) having an average particle diameter of 1 to 20 μm. The light-diffusible plate comprises the light-diffusible thermoplastic resin composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides light diffusion with improved light diffusivity, brightness, mechanical strength, and thermal stability by blending polycaprolactone, other transparent thermoplastic resins, silicone rubber particles having a specific structure, and a phosphorescent agent. The present invention relates to a thermoplastic resin composition and a light diffusing plate comprising the same. Specifically, for members that cover the light source, for example, light diffusing plates of direct-type backlight units and edge light type units of liquid crystal televisions, glove boxes of lighting fixtures, switches of various devices, and general applications that require light diffusibility The present invention provides a light diffusing thermoplastic resin composition suitably used and a light diffusing plate formed by molding the same.

  Transparent thermoplastic resins are widely used in the fields of electricity, electronics, OA, automobiles and the like because of their light transmission properties. In each field, resins that satisfy the required performance are selected and used separately. Yes. In particular, in applications such as liquid crystal television direct type and edge light type units, lighting fixture covers, and switches of various devices, if a transparent thermoplastic resin is used, the light source can be seen through because it transmits light, There is a demand for a material imparted with light diffusibility without recognizing the shape of the light source (lamp) behind the resin molded product and without impairing the luminance of the light source as much as possible.

  For the purpose of imparting light diffusibility to a transparent thermoplastic resin, in the prior art, there is a method in which a polymer phase or inorganic particle having a different refractive index is blended as a dispersed phase with a thermoplastic resin that forms a continuous phase. It has been adopted. In addition, a method for expressing desired light diffusibility by adjusting the range of the difference in refractive index between the dispersed phase and the continuous phase and the size of the particles in the dispersed phase has been proposed. (See Patent Documents 1 and 2)

  In order to obtain a higher degree of light diffusibility and brightness, the applicant of the present invention has disclosed a composition comprising a transparent thermoplastic resin and a light diffusing agent and polycaprolactone (see Patent Document 3) and transparent thermoplasticity. The composition (refer patent document 4) formed by mix | blending a light-diffusion agent and a luminous agent with resin was proposed.

  On the other hand, not only is the light diffusing plate excellent in light diffusibility and brightness, but particularly in the light diffusing plate for a direct type unit of a large-sized liquid crystal television, the light diffusing plate is required for reducing the thickness of the unit itself and reducing the cost. Therefore, there is a need for a light diffusing plate having mechanical strength that can meet the demand.

JP-A-60-184559 Japanese Patent Laid-Open No. 3-143950 JP 2006-83309 A JP 2006-335993 A

  The present invention not only provides high light diffusibility and brightness, but also has high mechanical strength even in applications such as thin light diffusing plates used for direct type units of large liquid crystal televisions. An object of the present invention is to provide a light diffusing thermoplastic resin composition and a light diffusing plate comprising the same.

  As a result of intensive studies in view of such problems, the present inventors have found that high optical performance and mechanical strength are obtained by blending polycaprolactone, specific silicone rubber particles, and a phosphorescent agent with a transparent thermoplastic resin. The present inventors have found a light diffusing thermoplastic resin composition capable of obtaining a light diffusing plate having the above, and completed the present invention.

  That is, in the present invention, 100 parts by weight of a resin component consisting of 0.1 to 7% by weight of polycaprolactone (A) and 93 to 99.9% by weight of other transparent thermoplastic resin (B) and an average particle size of 0 0.1 to 1.5 parts by weight of a silicone rubber particle (C) having a skeleton composed of a bifunctional siloxane unit and a trifunctional siloxane unit and an alkyl group on the surface and an average particle diameter of 5 to 10 μm The present invention relates to a light diffusing thermoplastic resin composition comprising 0.03 to 1 part by weight of a phosphorescent agent (D) having a size of 1 to 20 μm and a light diffusing plate formed by molding the same.

  The light diffusing plate obtained by molding the light diffusing thermoplastic resin composition of the present invention has high mechanical properties that can withstand the thinning of the light diffusing plate in addition to the optical performance of high light diffusibility and brightness. Has strength. For this reason, it is suitable for members that cover the light source, that is, diffuser plates for liquid crystal television direct-type backlight units and edge light type units, glove boxes for lighting fixtures, switches for various devices, and general applications that require light diffusibility. The practical utility value is extremely high.

  The polycaprolactone (A) used in the present invention is a polymer produced by ring-opening polymerization of ε-caprolactone in the presence of a catalyst, and in particular, a homopolymer of 2-oxepanone is preferably used. Examples of commercially available polymers include tone polymers manufactured by Dow Chemical Company, CAPA manufactured by Solvay Company, and the like. The viscosity average molecular weight of the polycaprolactone (A) is preferably 10,000 to 100,000, more preferably 40,000 to 90,000.

  In addition, polycaprolactone (A) includes a modified polycaprolactone in which ε-caprolactone is modified by ring-opening polymerization in the presence of 1,4-butanediol or the like, or a molecular end substituted with an ether or ester group. Is also included.

  The composition ratio of the polycaprolactone (A) is 0.1 to 7% by weight based on the resin components (A) and (B) made of the other transparent thermoplastic resin (B). When the composition ratio is less than 0.1% by weight, the light diffusion effect cannot be obtained and sufficient luminance cannot be obtained, which is not preferable. On the other hand, if it exceeds 7% by weight, sufficient thermal stability and mechanical strength cannot be obtained, which is not preferable. A more preferable composition ratio is 0.3 to 5% by weight.

  Examples of the transparent thermoplastic resin (B) used in the present invention include polycarbonate resin, polymethyl methacrylate, polystyrene, acrylonitrile / styrene copolymer, methacrylate / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, and the like. Examples thereof include styrene-based copolymers, polyesters, polyetherimides, polyimides, polyamides, modified polyphenylene ethers, polyarylate, cycloolefin polymers, and polymer alloys obtained by blending polycarbonate and polyester. In particular, polycarbonate resin, polymethyl methacrylate, methyl methacrylate / styrene copolymer, polyarylate, styrene copolymer resin, or cycloolefin polymer is preferably used. The degree of transparency of the thermoplastic resin (B) is such that the observer recognizes the object when light is transmitted and the molded article of the resin is interposed between the observer and the object such as a light source. The performance that can be done.

  The polycarbonate resin used in the present invention is a polymer obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example is polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone Sulfone, and the like. These are used individually or in mixture of 2 or more types. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be mixed and used.

  Furthermore, the above dihydroxyaryl compound and a trivalent or higher phenol compound as shown below may be used in combination. Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The viscosity average molecular weight of the polycarbonate resin is usually 10,000 to 100,000, preferably 15,000 to 35,000, and more preferably 17,000 to 28,000. In producing such a polycarbonate resin, a molecular weight regulator, a catalyst and the like can be used as necessary.

The silicone rubber particles (C) used in the present invention are composed of a skeleton of a bifunctional siloxane unit represented by the following general formula 1 and a trifunctional siloxane unit represented by the following general formula 2, and further an alkyl group of the particles. It exists on the surface.
General formula 1

一般式２

General formula 2

上記一般式１および一般式２において、Ｒ^１、Ｒ^２およびＲ^３はそれぞれ同一でも異なっていてもよいアルキル基を示す。

In the said General formula 1 and General formula 2, R < ¹ >, R < ² > and R < ³ > show the alkyl group which may be same or different, respectively.

  The ratio of the bifunctional siloxane unit in the skeleton constituting the silicone rubber particles (C) of the present invention is preferably 30 to 95% by weight, more preferably 40 to 70% by weight. The larger the ratio of the bifunctional siloxane unit, the lower the glass transition temperature (Tg) of the silicone rubber and the lower the refractive index.

  The trifunctional siloxane unit is preferably 5 to 70% by weight, more preferably 30 to 60% by weight of the siloxane unit constituting the silicone rubber particle (C). Trifunctional siloxane units are used to make silicone rubber a cross-linked structure, which can increase the refractive index.

The silicone rubber particles (C) of the present invention can be produced by a known method. First, as described in, for example, “Synthesis and Application of Organosilicon Polymer” (published by CMC Co., Ltd., November 30, 1989), the skeleton is co-hydrolyzed of bifunctional and trifunctional chlorosilanes or alkoxysilanes. There is a method by co-condensation. By selecting an alkyl group directly bonded to Si of chlorosilane or alkoxysilane used at this time, R ¹ , R ² and R ³ can be determined. Among these, an alkyl group having 1 to 6 carbon atoms, particularly a methyl group is preferable.

  What is necessary is just to select the quantity ratio of a bifunctional siloxane unit and a trifunctional siloxane unit with Tg and refractive index of desired silicone rubber particle (C). In addition, −50 to −200 ° C. is suitable for the Tg of the silicone rubber particles (C). A refractive index of 1.39 to 1.46 is suitable.

  The average particle diameter of the silicone rubber particles (C) of the present invention is 0.5 to 10 μm. When the average particle size is less than 0.5 μm, sufficient light diffusibility cannot be exhibited, which is not preferable. On the other hand, if it exceeds 10 μm, the transmitted light decreases, which is not preferable. Preferably, it is the range of 2-4 micrometers.

  Examples of such silicone rubber particles include “Trefill E-600” and “Trefill E-606” manufactured by Toray Dow Corning Silicone.

  The compounding amount of the silicone rubber particles (C) is 0.1 to 1.5 parts by weight (polycaprolactone (A) 0.1 to 7% by weight and other transparent thermoplastic resins (B) 93 to 99.9. Per 100 parts by weight of the resin component consisting of% by weight). When the blending amount is less than 0.1 parts by weight, it is difficult to obtain a sufficient light diffusion effect and a sufficient mechanical strength cannot be obtained, which is not preferable. On the other hand, if the amount exceeds 1.5 parts by weight, the light transmission property is impaired, and sufficient light diffusion performance cannot be obtained. More preferably, it is in the range of 0.5 to 1.2 parts by weight.

  The phosphorescent agent (D) used in the present invention refers to an agent that stores light such as ultraviolet rays and continues to emit light for a long time in the form of light emission even after the irradiation with light is stopped. Is distinguished from general fluorescent whitening agents, etc., which have persistence afterglow for several minutes to several tens of hours and whose light emission decays rapidly after light irradiation is stopped.

The phosphorescent agent (D) is a sulfide-based phosphorescent agent such as CaS: Bi, CaSrS: Bi, ZnCdS: Cu, a zinc sulfide-based phosphorescent agent such as ZnS: Cu, or a compound represented by MA _a 1 _b O _c. , M is composed of at least one metal element selected from calcium, strontium and barium, and europium, lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium as an activator for the compound And aluminate-based compounds containing at least one element selected from ytterbium, ruthenium, manganese, tin, and bismuth, and usually contained in an amount of 10 mol% or less with respect to the metal element represented by M. . From the viewpoint of hydrolyzability and afterglow characteristics, an aluminate compound is preferable, and a strontium aluminate compound using strontium as a metal element and europium or dysprosium as an activator is more preferable.

  Furthermore, the phosphorescent agent (D) is required to have an average particle diameter of 1 to 20 μm. More preferably, it is the range of 2-17 micrometers. Those having a thickness of less than 1 μm are not preferable because they are difficult to manufacture and are not practical and difficult to obtain. On the other hand, if it exceeds 20 μm, the luminance is lowered, which is not preferable. The particle size distribution is not particularly limited, but is about 0.1 to 100 μm, preferably 0.5 to 80 μm. Furthermore, two or more types of phosphorescent agents having different average particle diameters, particle size distributions, and types may be used in combination, and those having two or more particle size distributions that are not uniform are used alone or in combination. Can also be used.

  As a compounding quantity of a luminous agent (D), it is 0.03-1 weight part (Polycaprolactone (A) 0.1-7 weight% and other transparent thermoplastic resins (B) 93-99.9 weight%) Per 100 parts by weight of resin component). If the blending amount is less than 0.03 parts by weight, the luminance decreases, which is not preferable. On the other hand, if it exceeds 1 part by weight, sufficient thermal stability and mechanical strength cannot be obtained, which is not preferable. More preferably, it is 0.05 to 0.5 part by weight. By using the silicone rubber particles (C) and the phosphorescent agent (D) in combination, a more excellent surface light emission (brightness) is achieved as compared with the conventional use of the silicone rubber particles (C) alone. be able to.

  The light diffusing thermoplastic resin composition of the present invention includes known additives other than those described above, for example, antioxidants [phosphite antioxidants, phosphate antioxidants, phosphonite antioxidants, and these Ester antioxidants, etc.], UV absorbers [benzophenone UV absorbers, benzotriazole UV absorbers, triazine UV absorbers, malonic ester UV absorbers, oxanilide UV absorbers, etc.], lubricants [paraffins] Wax, n-butyl stearate, synthetic beeswax, natural beeswax, glycerin monoester, montanic acid wax, polyethylene wax, pentaerythritol tetrastearate, etc.], colorant [eg titanium oxide, carbon black, dye], filler [carbonic acid Calcium, clay, silica, glass fiber, glass bulb, gas Flakes, carbon fibers, talc, mica, various whiskers, etc.], fluidity improvers, spreading agents [epoxidized soybean oil, liquid paraffin, etc.], and other thermoplastic resins and various impact modifiers (polybutadiene, Rubber reinforced resin obtained by graft polymerization of a compound such as methacrylic acid ester, styrene or acrylonitrile to rubber such as polyacrylic acid ester or ethylene / propylene rubber is exemplified. Also good.

  There is no restriction | limiting in the embodiment and order in this invention. For example, polycaprolactone (A), transparent thermoplastic resin (B), silicone rubber particles (C) and phosphorescent agent (D) are weighed in arbitrary amounts and mixed together by a tumbler, riboblender, high-speed mixer, etc. Then, the mixture is melt-kneaded using a normal single-screw or twin-screw extruder and pelletized, or some or all of each component is weighed separately and fed into the extruder from multiple feeders. The method of melt-mixing, further blending (A), (C) and (D) at a high concentration, once melt-mixed and pelletized to obtain a master batch, and then the master batch and (B) The desired ratio can be mixed. Then, when these components are melt-mixed, arbitrary conditions such as the position at which the extruder is introduced, the extrusion temperature, the screw rotation speed, the supply amount, and the like can be selected and pelletized. Further, the masterbatch and (B) can be directly mixed into an injection molding machine or a sheet extruder after dry mixing at a desired ratio to obtain a molded product. The method for subjecting the light diffusing thermoplastic resin composition of the present invention to molding is not particularly limited, and known injection molding methods, injection compression molding methods, extrusion molding methods, and the like can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. Unless otherwise specified, “%” and “parts” in the examples are based on weight standards.

The raw materials used are as follows.
Polycaprolactone:
CAPA6500C made by Solvay
(Viscosity average molecular weight: 50000, hereinafter abbreviated as PCL)
Polycarbonate resin:
Sumitomo Dow Caliber 200-13
(Viscosity average molecular weight: 25000, hereinafter abbreviated as PC)
Silicone rubber particles:
TORAYFIL E-606 made by Toray Dow Corning Silicone
(Dimethylpolysiloxane, hereinafter abbreviated as LD-1)
TORAYFIL E-601 made by Toray Dow Corning Silicone
(Epoxy-modified dimethylpolysiloxane, hereinafter abbreviated as LD-2)
Acrylic light diffusing agent:
Acrylic diffusing agent EXL-5136 manufactured by Rohm and Haas
(Hereinafter abbreviated as LD-3)
Luminescent agent:
G-300FF manufactured by Nemoto Special Chemical Co., Ltd.
(Average particle size 4.3 μm, strontium aluminate phosphorescent agent, hereinafter abbreviated as CL)

  A method for measuring various evaluation items in the present invention will be described.

1. Luminance between lamps Placed on the back side of a flat plate test piece (length: 90 mm, width: 50 mm, thickness: 2 mm) made by injection molding machine with two cold cathode tubes, the surface of the test piece in the vertical direction between the lamps The above luminance was measured with a luminance meter BM-7 manufactured by Topcon Corporation. Note that the luminance means a ratio per unit area of a light intensity directed in a certain direction on a surface perpendicular to the direction, and generally represents a degree of brightness of the light emitting surface [unit: (cd / m ² ). ]. As a criterion for evaluation, a lamp having a measured value of luminance between lamps of 3300 cd / m ² or more was determined to be acceptable (◯), and a value of less than 3300 cd / m ² was determined to be unacceptable (x). An outline of the measurement method is shown in FIG.

2. Mechanical strength In accordance with ASTM D-256 standard, using a notched Izod test piece (length: 6.3 mm, width: 1.3 mm, thickness: 1/8 inch) produced by an injection molding machine, Toyo The mechanical strength (impact strength) was measured with an Izod testing machine manufactured by Seiki. As a criterion for evaluation, a sample having an impact strength of 30 kg · cm / cm or higher was determined to be acceptable (◯), and a sample having an impact strength of less than 30 kg · cm / cm was determined to be unacceptable (x).

3. Thermal stability After making flat plate test pieces before and after staying for 15 minutes at a cylinder set temperature of 320 ° C. with an injection molding machine, change the yellowness with a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory) ( ΔYI) was measured. ΔYI represents the difference in yellowness before and after the stay, and the smaller the ΔYI, the smaller the color change and the better the light resistance. As a criterion for the evaluation of ΔYI, a case where the value of ΔYI was less than 5.5 was judged as acceptable (◯), and a case where it was 5.5 or more was regarded as unacceptable (x).

4). Comprehensive judgment In the following Tables 1 to 3, in the evaluation of inter-lamp luminance, mechanical strength, and thermal stability, those satisfying all were determined to be acceptable (◯), and those not satisfied were determined to be unacceptable (x).

  In the blending components and blending ratios shown in Tables 1 to 3, various blending components were dry-mixed with a tumbler, and then a twin-screw extruder (KTX-37 manufactured by Kobe Steel, shaft diameter = 37 mmφ, L / D = 30) was used for melt kneading at a temperature of 250 to 290 ° C. Using the obtained pellets, a flat plate test piece for luminance measurement having a length of 90 mm, a width of 50 mm, and a thickness of 2 mm under the conditions of a cylinder setting temperature of 300 ° C. using an injection molding machine (J100E2P manufactured by Nippon Steel Works) A Charpy test piece according to the ISO standard was prepared. In addition, for the purpose of evaluating thermal stability, a length of 90 mm, a width of 50 mm, and a thickness of 2 mm are obtained after using an injection molding machine (J100E2P manufactured by Nippon Steel Works) for 15 minutes at a cylinder setting temperature of 320 ° C. A flat plate test piece was prepared. The measured values and evaluation results are shown in Tables 1-3.

  As shown in Table 1, when the configuration of the present invention was satisfied (Examples 1 to 5), all evaluation items had sufficient performance.

On the other hand, as shown in Tables 2 and 3, when the configuration of the present invention was not satisfied, each case had some drawbacks.
Comparative Example 1 was a case where the blending amount of polycaprolactone was less than the specified amount, and although the mechanical strength and thermal stability passed, the inter-lamp luminance was inferior.
Comparative Example 2 was a case where the blending amount of polycaprolactone was larger than the specified amount, and the luminance between lamps passed, but the mechanical strength and thermal stability were inferior.
Comparative Example 3 was a case where the blending amount of the silicone rubber particles having a methyl group was less than the specified amount, and although the thermal stability passed, the inter-lamp luminance and mechanical strength were inferior.
Comparative Example 4 was a case where the blending amount of the silicone rubber particles having a methyl group was larger than the specified amount, and although the mechanical strength and thermal stability passed, the inter-lamp luminance was inferior.
Comparative Example 5 was a case where silicone rubber particles having an epoxy group were used, and although the inter-lamp luminance and mechanical strength passed, the thermal stability was inferior.
Comparative Example 6 was a case where an acrylic light diffusing agent was used, and the inter-lamp luminance passed, but the mechanical strength and thermal stability were inferior.
Comparative Example 7 was a case where the amount of the phosphorescent agent was less than the prescribed amount, and the mechanical strength and thermal stability passed, but the inter-lamp luminance was inferior.
Comparative Example 8 was a case where the blending amount of the phosphorescent agent was larger than the specified amount, and the inter-lamp luminance passed, but the mechanical strength and thermal stability were inferior.

It is a figure which shows the measuring method of the brightness | luminance between lamps in this invention.

Explanation of symbols

A: Luminance meter B: Light beam C: Light diffusion plate D: Lamp (cold cathode tube)

Claims (10)

  100 parts by weight of a resin component consisting of 0.1 to 7% by weight of polycaprolactone (A) and 93 to 99.9% by weight of other transparent thermoplastic resin (B) and an average particle size of 0.5 to 10 μm. And 0.1 to 1.5 parts by weight of a silicone rubber particle (C) having a skeleton composed of a bifunctional siloxane unit and a trifunctional siloxane unit and an alkyl group on the surface, and an average particle diameter of 1 to 20 μm. A light diffusing thermoplastic resin composition comprising 0.03 to 1 part by weight of an agent (D).   The light-diffusing thermoplastic resin composition according to claim 1, wherein the polycaprolactone (A) has a viscosity average molecular weight of 40,000 to 90,000.   2. The light diffusing thermoplastic resin composition according to claim 1, wherein the composition ratio of the polycaprolactone (A) is 0.3 to 5% by weight.   The transparent thermoplastic resin (B) is one or more selected from polycarbonate resin, polymethyl methacrylate, methyl methacrylate / styrene copolymer, polyarylate, polystyrene, styrene copolymer resin or cycloolefin polymer. The light-diffusing thermoplastic resin composition according to claim 1.   2. The light diffusing thermoplastic resin composition according to claim 1, wherein the alkyl group on the surface of the silicone rubber particle (C) is a methyl group.   The average particle diameter of a silicone rubber particle (C) is 2-4 micrometers, The light diffusable thermoplastic resin composition of Claim 1 characterized by the above-mentioned.   The blending amount of the silicone rubber particles (C) is 0.5 to 1.2 parts by weight (polycaprolactone (A) 0.1 to 7% by weight and other transparent thermoplastic resins (B) 93 to 99.9. The light diffusing thermoplastic resin composition according to claim 1, wherein the composition is per 100 parts by weight of a resin component consisting of wt%. The compounding quantity of a luminous agent (D) is 0.05-0.5 weight part, The light diffusable thermoplastic resin composition of Claim 1 characterized by the above-mentioned. The light-diffusing thermoplastic resin composition according to claim 1, wherein the phosphorescent agent (D) is a strontium aluminate compound.   The light diffusing plate formed by shape | molding the light diffusable thermoplastic resin composition as described in any one of Claims 1-9.

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