JP2009006623A - Light diffusing polycarbonate resin plate excellent in antistatic property and light resistance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light diffusing polycarbonate plate which is excellent in antistatic property and light resistance without damaging luminance when incorporated in a surface light source body. <P>SOLUTION: The light diffusing polycarbonate resin plate is produced by co-extrusion molding of a surface layer consisting of a polycarbonate resin composition which contains specific amount of a specific antistatic agent and a specific UV ray absorber as essential components and further contains polycaprolactone, if desired, at least on one surface of a base material consisting of the polycarbonate resin composition containing a light dispersing agent C as the essential component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is obtained by coextruding a base material made of a polycarbonate resin having light diffusibility with a polycarbonate resin layer containing an antistatic agent and an ultraviolet absorber having a specific structure and, if desired, polycaprolactone as a surface layer. The present invention relates to a light diffusing polycarbonate resin plate.

  Polycarbonate resins are excellent in mechanical properties, heat resistance and light resistance, and are used in a wide range of applications as resins having high light transmittance. For example, it is also used in large quantities in the construction field of sky domes, top lights, arcades, condominium waistboards, and road sideboards. Many of these uses are milky white light diffusing plates. A method of mixing a polycarbonate resin with a light diffusing agent such as calcium carbonate, barium sulfate, silicon oxide, titanium oxide (Patent Document 1), a method of dispersing fine particles (patent) Document 2) has been proposed.

Japanese Patent Publication No.57-24186 Japanese Patent Laid-Open No. 05-257002

  Such a light diffusing polycarbonate resin plate is used in an edge light type or direct backlight type surface light source for a liquid crystal display and a surface light source for a scanner.

  The light diffusing plate described in Japanese Patent Publication No. 57-24186 and Japanese Patent Laid-Open No. 05-257002 described above has a minimum function as a member for diffusing light, but is actually incorporated in a surface light source body. In some cases, a problem such as adhesion of dust occurs, and display unevenness may occur on the liquid crystal screen due to a change in the use environment.

Generally, as a method for imparting antistatic performance to a polycarbonate resin, blending conductive carbon black or carbon fiber is performed. However, since these are black, application to optical uses such as a light diffusion plate has been difficult.
For applications other than black, metal salts of alkane sulfonates and alkylbenzene sulfonates are generally used as antistatic agents. However, when these are mixed with polycarbonate resin, the color tone becomes white and opaque, so that sufficient light transmission is achieved. Therefore, there is a problem that high brightness cannot be obtained as a surface light source body.

  In addition, although polycarbonate resin is excellent in light resistance, in the case of a light diffusing polycarbonate resin plate, since it is used in a surface light source body as described above, there is a problem of discoloration caused by exposure to light rays such as a cold cathode tube as a light source. There is also a need for further improvement in light resistance.

  For the purpose of imparting light resistance to a polycarbonate resin, it has been conventionally studied to add a benzotriazole-based or benzophenone-based UV absorber. However, when this method is applied to an antistatic polycarbonate resin, there is a problem that the initial hue is yellowish (initial coloring).

  An object of the present invention is to obtain a light-diffusing polycarbonate resin plate having excellent antistatic properties and light resistance without impairing luminance when incorporated in a surface light source body.

  As a result of intensive studies to solve the above problems, the present inventors have found that an antistatic agent and an ultraviolet absorber having a specific structure and, if desired, a polycaprolactone on at least one side of a substrate made of a light diffusing polycarbonate resin. The present inventors have found that a light diffusive polycarbonate resin plate having excellent antistatic properties and light resistance can be obtained by coextrusion molding of a polycarbonate resin layer containing bismuth.

That is, the present invention contains an antistatic agent and an ultraviolet absorber as essential components on at least one side of a base material made of a polycarbonate resin composition containing a light diffusing agent as an essential component, and further contains polycaprolactone in an amount of 0 if desired. In a light-diffusing polycarbonate resin plate obtained by coextrusion molding of a surface layer made of a polycarbonate resin composition, containing 0.01 to 15 parts by weight (per 100 parts by weight of a polycarbonate resin used for the surface layer),
The antistatic agent of the surface layer is an organic sulfonic acid phosphonium salt represented by the following general formula (1), and the content of the antistatic agent is 100 parts by weight of the polycarbonate resin used for the surface layer, More than 2.0 parts by weight and not more than 10 parts by weight, and the ultraviolet absorber is a compound represented by the following general formula (2), and the content of the ultraviolet absorber is used for the surface layer 0.01 to 0.8 parts by weight per 100 parts by weight of the polycarbonate resin
The present invention provides a light diffusing polycarbonate resin plate.
General formula (1)

（一般式（１）において、Ｒ１は炭素数１〜４０のアルキル基又はアリール基であり、Ｒ２〜Ｒ５は水素原子、炭素数１〜１０のアルキル基又はアリール基であり、これらは同じであっても異なっていてもよい。）
一般式（２）

(In the general formula (1), R1 is an alkyl group or aryl group having 1 to 40 carbon atoms, R2 to R5 are a hydrogen atom, an alkyl group or aryl group having 1 to 10 carbon atoms, and these are the same. Or different.)
General formula (2)

（一般式（２）において、Ｒ１は炭素数１〜１２のアルキル基、Ｒ２は炭素数１〜１２のアルコキシ基を表す。）

(In General Formula (2), R1 represents an alkyl group having 1 to 12 carbon atoms, and R2 represents an alkoxy group having 1 to 12 carbon atoms.)

  The light diffusing polycarbonate resin plate of the present invention has excellent antistatic properties, light resistance, light diffusing properties and brightness without impairing the transparency of the polycarbonate resin, and uses that require high optical performance, In particular, it is suitably used for a light diffusing plate used for a backlight for liquid crystal display devices.

  The polycarbonate resin used for the substrate and the surface layer of the present invention can be 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 of the polymer is a 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 used for the surface layer or the substrate 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 light diffusing agent used in the present invention is not particularly limited in terms of chemical composition such as polymer and inorganic, but a light diffusing agent is added to the polycarbonate resin component used in the substrate of the present invention, and extruded. When it is dispersed by a known method such as melt mixing by a machine, it is necessary that it is not compatible with the matrix phase or is present as particles that are hardly compatible.

Specific examples of the light diffusing agent include calcium carbonate, silica, silicone, zinc sulfide, zinc oxide, titanium oxide, titanium phosphate, magnesium titanate, magnesium titanate, mica, glass filler, barium sulfate, clay, talc, and silicone. Rubber-like elastic materials, inorganic diffusing agents such as polymethylsilsesoxane, acrylics, styrenes, polyesters, polyolefins, urethanes, nylons, methacrylate-styrenes, fluorines, norbornenes, etc. Examples include diffusing agents. In particular, silica, silicone or acrylic is preferably used.

  Furthermore, the particle size of the light diffusing agent is not particularly limited as long as desired light diffusibility can be obtained by adding the diffusing agent, but an average particle size of about 1 to 30 μm is preferable. Can be used. If the thickness is less than 1 μm, only light is transmitted, and it may be difficult to obtain a light diffusion effect. On the other hand, if it exceeds 30 μm, a sufficient light diffusion effect cannot be obtained and visibility may be inferior. Moreover, there is no restriction | limiting in particular as particle size distribution, However, It is about 0.1-100 micrometers, Furthermore, it can use more suitably in the range of 1.5-25 micrometers. Further, two or more kinds of light diffusing agents having different average particle sizes, particle size distributions, and types may be used in combination, and the particle size distribution is not uniform, and those having two or more particle size distributions are used alone or It can also be used in combination.

As a compounding quantity of a light-diffusion agent, 0.1-10 weight part is suitable for 100 weight part of polycarbonate resin of a base material. If the blending amount is less than 0.1 parts by weight, it may be difficult to obtain a sufficient light diffusion effect. On the other hand, if it exceeds 10 parts by weight, the light transmission property is impaired, and sufficient light diffusion performance and brightness may not be obtained. More preferably, it is the range of 0.3-5 weight part.

The antistatic agent used in the present invention is an organic sulfonic acid phosphonium salt represented by the following general formula (1).
General formula (1)

（一般式（１）において、Ｒ１は炭素数１〜４０のアルキル基又はアリール基であり、Ｒ２〜Ｒ５は水素原子、炭素数１〜１０のアルキル基又はアリール基であり、これらは同じであっても異なっていてもよい。）

(In the general formula (1), R1 is an alkyl group or aryl group having 1 to 40 carbon atoms, R2 to R5 are a hydrogen atom, an alkyl group or aryl group having 1 to 10 carbon atoms, and these are the same. Or different.)

Among the antistatic agents represented by the general formula (1), an antistatic agent represented by the following general formula (3) can be preferably used.
General formula (3)

  The amount of the antistatic agent used in the surface layer of the present invention is more than 2 parts by weight and 10 parts by weight or less per 100 parts by weight of the polycarbonate resin in the surface layer. If the blending amount is 2 parts by weight or less, the antistatic property is inferior, and if it exceeds 10 parts by weight, the thermal stability is lowered, which is not preferable. More preferably, it is in the range of 2.2 to 5 parts by weight.

The ultraviolet absorber used in the present invention is a compound represented by the following general formula (2).
General formula (2)

（一般式（２）において、Ｒ１は炭素数１〜１２のアルキル基、Ｒ２は炭素数１〜１２のアルコキシ基を表す。）

(In General Formula (2), R1 represents an alkyl group having 1 to 12 carbon atoms, and R2 represents an alkoxy group having 1 to 12 carbon atoms.)

As a specific example of the compound represented by the general formula (2), an aryl group substituted with an alkyl group and an aryl group substituted with an alkoxy group are symmetrically substituted with respect to two nitrogen atoms in the oxanilide skeleton. In particular, a compound represented by the following general formula (4) is preferably used.
General formula (4)

  The ultraviolet absorber is easily available as a commercial product, and examples include Sanduvor VSU manufactured by Clariant Japan.

  As a compounding quantity of the ultraviolet absorber used by this invention, it is 0.01-0.8 weight part per 100 weight part of polycarbonate resin of a surface layer. A blending amount of less than 0.01 part by weight is not preferable because sufficient light resistance cannot be obtained. On the other hand, if it exceeds 8 parts by weight, the thermal stability is deteriorated, which is not preferable. More preferably, it is the range of 0.1-0.6 weight part.

  The polycaprolactone used in the present invention is a polymer produced by ring-opening polymerization of ε-caprolactone in the presence of a catalyst, and a 2-oxepanone homopolymer is particularly preferably used. The polymer is easily available as a commercial product, and a tone polymer manufactured by Dow Chemical Company, CAPA manufactured by Solvay Company, and the like are used. The viscosity average molecular weight of polycaprolactone is preferably 10,000 to 100,000, more preferably 40,000 to 90,000.

  Further, polycaprolactone includes those modified by coexisting with ε-caprolactone in the presence of 1,4-butanediol or the like, and modified polycaprolactone substituted with an ether or ester group at the molecular end. . When this polycaprolactone is used in combination with an antistatic agent, although the mechanism of manifestation of the effect is unknown, a synergistic effect on antistatic properties is found, and it has an excellent effect of not causing a decrease in transparency.

  The compounding quantity of polycaprolactone is 0.01-15 weight part per 100 weight part of polycarbonate resin of a surface layer. A blending amount of less than 0.01 parts by weight is not preferable because a sufficient antistatic synergistic effect cannot be obtained. On the other hand, if it exceeds 15 parts by weight, the transparency is lowered and the luminance is lowered, which is not preferable. A more preferable composition ratio is 0.1 to 7 parts by weight.

  In the light diffusing polycarbonate resin plate of the present invention, various known additives, polymers, etc. may be added to the base material and / or the surface layer as necessary depending on the performance required in addition to the light diffusing property. it can. For example, in order to suppress discoloration of the resin molded product when exposed to light for a long period of time, a hindered amine-based light-resistant stabilizer is used, and further, in order to obtain a vivid color tone, a benzoxazole-based fluorescent whitening agent and These may be added in combination.

  In the light diffusing polycarbonate resin plate of the present invention, known additives other than those described above, for example, phenol-based or phosphorus-based heat stabilizer [2,6-di-t-butyl-4-methylphenol, 2- (1- Methylcyclohexyl) -4,6-dimethylphenol, 4,4'-thiobis- (6-tert-butyl-3-methylphenol), 2,2-methylenebis- (4-ethyl-6-tert-methylphenol), n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tris (2,4-di-t-butylphenyl) phosphite, 4,4′-biphenylenediphosphinic acid tetrakis (2,4-di-t-butylphenyl), etc.], lubricant [paraffin wax, n-butyl stearate, synthetic beeswax, natural beeswax, glycerin monoester Montanic acid wax, polyethylene wax, pentaerythritol tetrastearate, etc.], colorant [eg dye], filler [calcium carbonate, clay, silica, glass fiber, glass sphere, glass flake, carbon fiber, talc, mica, various whiskers Etc.], fluidity improvers, spreading agents [epoxidized soybean oil, liquid paraffin, etc.], and other thermoplastic resins and various impact modifiers (polybutadiene, polyacrylates, ethylene / propylene rubbers, etc.) Rubber reinforced resin obtained by graft polymerization of a compound such as methacrylic acid ester, styrene, acrylonitrile, etc.) may be added to the rubber as required.

Embodiments and order in the present invention are shown below.
Weigh the polycarbonate resin used for the light diffusing agent and the base material in an arbitrary blending amount, and after batch mixing with a tumbler, ribbon blender, high-speed mixer, etc., melt and knead the mixture using a normal single or twin screw extruder And pelletizing, or each component is weighed separately, introduced into the extruder from multiple feeders, melt mixed, and a light diffusing agent is added to the polycarbonate resin at a high concentration. Once melt-mixed and pelletized into a master batch, the master batch and polycarbonate resin can be mixed at a desired ratio.
Then, when these components are melt-mixed, arbitrary conditions such as a position to be introduced into the extruder, an extrusion temperature, a screw rotation speed, a supply amount, and the like can be selected and pelletized. Thereby, the pellet for base materials is obtained.
Further, an antistatic agent and an ultraviolet absorber, further polycaprolactone as required, and a polycarbonate resin used for the surface layer are weighed in an arbitrary blending amount, and pellets for the surface layer are obtained using the same method as described above. be able to.
The resulting pellets for the substrate and surface layer are melted and kneaded with 2 to 3 uniaxial or biaxial extruders respectively, and then supplied to the substrate feed block and the surface layer feed block of the coextrusion die, respectively. And a laminated sheet is obtained.

  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.

The raw materials used are as follows.
Polycarbonate resin:
Caliber 200-13 manufactured by Sumitomo Dow
(Viscosity average molecular weight: 21500, hereinafter abbreviated as PC)
CAPA6500C manufactured by Polycaprolactone Solvay
(Viscosity average molecular weight: 50000, hereinafter abbreviated as PCL)
Light diffusing agent:
MSP-S020 made by Nikko Rica
(Polymethylsilsesoxane-based diffusing agent, hereinafter abbreviated as LD-1)
GM0449S manufactured by Gantz Kasei
(Acrylic diffusing agent, hereinafter abbreviated as LD-2)
Antistatic agent:
Elecut S-418 made by Takemoto Yushi Co.
(Phosphonium salt of alkylbenzene sulfonate)
UV absorber:
Sanduvor VSU made by Clariant Japan
N- (2-Ethylphenyl) -N ′-(2-ethoxyphenyl) oxalic acid diamide (Oxanilide ultraviolet absorber, hereinafter abbreviated as UVA-1)
Tinuvin 329 manufactured by Ciba Specialty Chemicals
(Benzotriazole ultraviolet absorber, hereinafter abbreviated as UVA-2)

  The above-mentioned various raw materials were each put into a tumbler at the mixing ratio for the base material or surface layer material shown in Tables 1 to 3, and after dry mixing for 10 minutes, a twin-screw extruder (TEX30α manufactured by Nippon Steel Works) was used. Then, the mixture was kneaded at a melting temperature of 260 ° C. to obtain pellets for the base material or surface layer material.

  The obtained base material and surface layer material pellets were each dried in advance under a drying condition of 125 ° C. × 2 hours. Next, the substrate pellets that had been pre-dried were put into a substrate extruder (VS40 single-screw extruder (L / D = 32, 40Φ) manufactured by Tanabe Plastics Co., Ltd.) for co-extrusion at 260 ° C. Supplied from the die substrate feed block. At the same time, pre-dried pellets for the surface layer are put into a surface layer extruder (PEX Giken PEX-25-24 single screw extruder (L / D = 24, 25Φ)), and the surface layer material is fed at 260 ° C. Was subjected to melt extrusion to obtain a coextruded sheet.

  Hereinafter, various evaluation items and measurement methods in the present invention will be described.

1. Surface resistivity (Rs):
The obtained co-extruded sheet was cut into a thickness of 90 × 50 × 2 mm, and after conditioning for 24 hours under the conditions of 23 ° C. and 50% relative humidity, a super insulation meter (SME 8311 manufactured by Sicid Electrostatic Co., Ltd.) was used. The surface resistance value was measured under the conditions of a measurement voltage of 1000 V and a sampling time of 30 seconds. As a criterion for evaluation, those having a surface resistivity Rs of less than 1 × 10 ¹⁴ were accepted (◯), and those having a surface resistivity of 1 × 10 ¹⁴ or more were rejected (x).

2. Half-life:
The obtained co-extruded sheet was cut into a thickness of 90 × 50 × 2 mm, and the half-life was measured with a static Honest meter (H-0110 manufactured by Sicid electrostatic company). First, an electric charge of 10 KV is continuously applied until the withstand voltage of the test piece becomes constant. Thereafter, the charge was stopped, the decay of the charged voltage was observed, and the time until the initial charged voltage was halved was measured to determine the half-life. As a criterion for evaluation, a sample having a half-life of 30 seconds or less was accepted (◯), and a sample having a half-life of 30 seconds or more was rejected (x).

3. Measurement of Luminance Two cold cathode tubes were placed on the back side of a coextruded sheet (90 × 50 × 2 mm thickness) cut, and the luminance on the surface of the test piece in the vertical direction between the lamps was measured. The luminance means the ratio of the luminous intensity directed in a certain direction per unit area in a plane perpendicular to the direction, and generally represents the degree of brightness of the light emitting surface [unit: (cd / m ² ). ]. Moreover, as a standard of evaluation, the thing whose measured value of the brightness | luminance between lamps is 3100 cd / m < ² > or more was set as the pass ((circle)), and less than 3100 cd / m < ² > was made disqualified (x). An outline of the measurement method is shown in FIG.

4). Evaluation of initial colorability and light resistance The obtained coextruded sheet was cut into a thickness of 90 × 50 × 2 mm, and placed in a super accelerated weathering tester iSuper UV Tester (SUV-W13 manufactured by Iwasaki Electric Co., Ltd.). Time irradiation was performed. Thereafter, the yellowness index (YI) of the sample before and after irradiation was measured with a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory) in accordance with ASTM D-1925. YI represents the degree of yellowness before irradiation. The smaller the YI, the smaller the yellowishness and the less the initial coloring. As YI evaluation criteria, a YI value of less than 6 was accepted (◯), and a YI value of 6 or more was rejected (x).
ΔYI represents the degree of yellowness before and after irradiation. The smaller ΔYI, the smaller the color change and the better the light resistance. As an evaluation criterion for ΔYI, a case where the value of ΔYI was less than 8 was judged as acceptable (◯), and a case where it was 8 or more was regarded as unacceptable (x).

5). Comprehensive judgment For Tables 1 to 3 below, in the evaluation of antistatic properties (surface specific resistance and half-life), luminance between lamps, initial coloration and light resistance, those that satisfy all are acceptable (O) those that are not It was set as a pass (x).

As shown in Table 1 and Table 2, when the configuration of the present invention was satisfied (Examples 1 to 9), all the evaluation items had sufficient performance.

On the other hand, as shown in Table 3, when the configuration of the present invention was not satisfied, Comparative Example 1 which had some disadvantages in any case was a case where the blending amount of the antistatic agent was less than the prescribed amount, Although the inter-lamp brightness, light resistance and initial colorability passed, the antistatic property was poor.
Comparative Example 2 was a case where the blending amount of the antistatic agent was larger than the specified amount, and although the antistatic property, the luminance between lamps and the light resistance passed, the initial colorability was inferior.
Comparative Example 3 was a case where the blending amount of the oxanilide ultraviolet absorber was less than the specified amount, and although the antistatic property, the luminance between the lamps and the initial colorability passed, the light resistance was inferior.
Comparative Example 4 was a case where the blending amount of the oxanilide ultraviolet absorber was larger than the prescribed amount, and although the antistatic property, the luminance between the lamps and the light resistance passed, the initial colorability was inferior.
Comparative Example 5 was a case where the blending amount of polycaprolactone was larger than the prescribed amount, and although the antistatic property, initial colorability, and light resistance passed, the inter-lamp luminance was inferior.
In Comparative Example 6, when different types of ultraviolet absorbers were used, the initial colorability was inferior although the antistatic property, the luminance between the lamps and the light resistance passed.

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 (7)

Light obtained by coextrusion molding a surface layer made of a polycarbonate resin composition containing an antistatic agent and an ultraviolet absorber as essential components on at least one side of a substrate made of a polycarbonate resin composition containing a light diffusing agent as an essential component In the diffusible polycarbonate resin plate,
The antistatic agent of the surface layer is an organic sulfonic acid phosphonium salt represented by the following general formula (1), and the content of the antistatic agent is 100 parts by weight of the polycarbonate resin used for the surface layer, More than 2.0 parts by weight and not more than 10 parts by weight, and the ultraviolet absorber is a compound represented by the following general formula (2), and the content of the ultraviolet absorber is used for the surface layer 0.01 to 0.8 parts by weight per 100 parts by weight of the polycarbonate resin
A light diffusing polycarbonate resin plate characterized by the above.
General formula (1)

(In the general formula (1), R1 is an alkyl group or aryl group having 1 to 40 carbon atoms, R2 to R5 are a hydrogen atom, an alkyl group or aryl group having 1 to 10 carbon atoms, and these are the same. Or different.)
General formula (2)

(In General Formula (2), R1 represents an alkyl group having 1 to 12 carbon atoms, and R2 represents an alkoxy group having 1 to 12 carbon atoms.) A surface layer composed of a polycarbonate resin composition containing antistatic agents, ultraviolet absorbers and polycaprolactone as essential components is coextruded on at least one surface of a substrate composed of a polycarbonate resin composition containing the light diffusing agent as an essential component. In the light diffusing polycarbonate resin plate,
The antistatic agent of the surface layer is an organic sulfonic acid phosphonium salt represented by the following general formula (1), and the content of the antistatic agent is 100 parts by weight of the polycarbonate resin used for the surface layer, More than 2.0 parts by weight and not more than 10 parts by weight, and the ultraviolet absorber is a compound represented by the following general formula (2), and the content of the ultraviolet absorber is used for the surface layer 0.01 to 0.8 parts by weight per 100 parts by weight of the polycarbonate resin, and the content of polycaprolactone is 0.01 to 15 parts by weight per 100 parts by weight of the polycarbonate resin used for the surface layer is there,
A light diffusing polycarbonate resin plate characterized by the above.
General formula (1)

(In the general formula (1), R1 is an alkyl group or aryl group having 1 to 40 carbon atoms, R2 to R5 are a hydrogen atom, an alkyl group or aryl group having 1 to 10 carbon atoms, and these are the same. Or different.)
General formula (2)

(In General Formula (2), R1 represents an alkyl group having 1 to 12 carbon atoms, and R2 represents an alkoxy group having 1 to 12 carbon atoms.) 3. The light diffusing polycarbonate resin plate according to claim 1, wherein the antistatic agent contains an alkylbenzenesulfonic acid phosphonium salt represented by the following general formula (3) as an active ingredient.
General formula (3)

  The light-diffusing polycarbonate resin plate according to claim 1 or 2, wherein the blending amount of the antistatic agent is 2.2 to 5 parts by weight per 100 parts by weight of the polycarbonate resin in the surface layer. The light diffusing polycarbonate resin plate according to claim 1 or 2, wherein the ultraviolet absorber contains a compound represented by the following general formula (4) as an active ingredient.
General formula (4)

  The light-diffusing polycarbonate resin plate according to claim 1 or 2, wherein the blending amount of the ultraviolet absorber is 0.1 to 0.6 parts by weight per 100 parts by weight of the polycarbonate resin in the surface layer.   The light-diffusing polycarbonate resin plate according to claim 2, wherein the compounding amount of polycaprolactone is 0.1 to 7 parts by weight per 100 parts by weight of the polycarbonate resin used for the surface layer.

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