JPH1046022A - Light diffusing resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light diffusing resin composition which is a molding material, excellent in light diffusing effects and suitable for a light diffusion plate and concretely having a high total light transmittance and a high haze (a ratio of the diffused light transmittance to the total light transmittance). SOLUTION: This light diffusing resin composition is an aromatic polycarbonate resin containing a block of a polyorganosiloxane or a mixture of the resin with an aromatic polycarbonate resin without containing any block of the polyorganosiloxane. In this case, the resin composition comprises 100 pts.wt. aromatic polycarbonate based resin having 0.01-5wt.% content of the polyorganosiloxane and 0.01-30 pts.wt. beady crosslinked acrylic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-diffusing resin composition which is a molding material suitable for a light-diffusing plate used for a backlight diffusion plate for a liquid crystal screen, a signboard, a lighting device, a protective cover for an indicator lamp and the like. It is.

[0002]

2. Description of the Related Art A light diffusing plate is usually formed of a molded article such as a protective cover of a lighting fixture, and scattered light is generated by a light scatterer in which light emitted from a light source disposed behind the back is dispersed. The entire plate is uniformly bright, making the image of the light source invisible. A light diffusion plate having such a function is required to be bright, uniform and have a high light diffusion property. However, as a molding material necessary for producing such a light diffusion plate, a high total light transmittance and a haze (diffusion) are required. Light transmittance / Total light transmittance)
Is required.

Heretofore, there has been proposed a material in which an inorganic filler such as glass fiber, barium sulfate, titanium oxide, talc, or the like is dispersed on a base material of a polycarbonate resin having excellent transparency, impact resistance, and heat resistance. However, even if these fillers are dispersed, the total light transmittance is reduced, resulting in a dark light diffusion plate,
Only poor performance can be obtained. On the other hand, resin compositions in which styrene-cyclohexylmaleimide crosslinked particles or titanium oxide-containing styrene-cyclohexylmaleimide crosslinked particles are blended with a polycarbonate resin have been proposed (JP-A-4-161448, JP-A-4-161448).
161449 publication). These resin materials had high total light transmittance but could not sufficiently obtain diffused light, had insufficient haze, and lacked balance.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a molding material excellent in light diffusion effect suitable for a light diffusion plate under such circumstances. Specifically, the present invention relates to a molding material having a high total light transmittance and a haze. It is an object of the present invention to provide a light-diffusing resin composition having a high ratio of diffuse light transmittance to light transmittance).

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to develop a light-diffusing resin composition having the above-mentioned preferable properties, and as a result, mixed a bead-like crosslinked acrylic resin with a specific aromatic polycarbonate-based resin. As a result, the present inventors have found that the object of the present invention is achieved, and have completed the present invention. That is, the gist of the present invention is as follows. (1) An aromatic polycarbonate resin (A) containing a block of polyorganosiloxane or a mixture of the resin (A) and an aromatic polycarbonate resin (B) not containing a block of polyorganosiloxane, A light diffusing resin composition comprising 100 parts by weight of an aromatic polycarbonate resin having a content of 0.01 to 5% by weight and 0.01 to 30 parts by weight of a bead-like crosslinked acrylic resin. (2) The light diffusing resin composition according to the above (1), wherein the repeating unit of the polyorganosiloxane is represented by the formula (I).

[0006]

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[R ^a and R ^b are an alkyl group having 1 to 6 carbon atoms or a phenyl group, which may be the same or different. ]

[0008]

Embodiments of the present invention will be described below in detail. (1) Aromatic Polycarbonate Resin Containing Polyorganosiloxane Block The aromatic polycarbonate resin containing a polyorganosiloxane block used in the present invention is typically one in which the above repeating unit contains the formula (I). A more specific example is a block copolymer of a polyorganosiloxane represented by the formula (II) and an aromatic polycarbonate comprising a repeating unit represented by the formula (III).

[0009]

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[R ^{1 to} R ⁴ are alkyl groups having 1 to 8 carbon atoms (for example, methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, etc.) 6-20, preferably 6-18 aryl groups (e.g. phenyl, tolyl, xylyl,
A naphthyl group), which may be the same or different. Y is a divalent organic residue containing an aliphatic or aromatic group, for example, a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an ethylidene group, an isopropylidene group, a cyclopentylene group, and a cyclohexylene group. , Cyclopentylidene group, cyclohexylidene group and the like, o-allylphenol residue, p
-Vinylphenol residues, eugenol residues, bisphenol A residues and the like. n is an integer of 1 to 500. ]

[0011]

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[R ⁵ and R ⁶ are a halogen atom (a chlorine atom, a bromine atom, a fluorine atom, an iodine atom) and an alkyl group having 1 to 8 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, an n-
Butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, etc.) or 6-20 carbon atoms, preferably 6-1 carbon atoms.
And 8 aryl groups (for example, a phenyl group, a tolyl group, a xylyl group, and a naphthyl group), which may be the same or different. p and q are integers of 0-4. Z is a single bond, an alkylene group having 1 to 20, preferably 2 to 18 carbon atoms or an alkylidene group (for example, a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an ethylidene group, an isopropylidene group, etc.) A C5-20 cycloalkylene group or a cycloalkylidene group (e.g., a cyclopentylene group, a cyclohexylene group, a cyclopentylidene group, a cyclohexylidene group, etc.), an alkylene ester group, an alkylenecarbonyl group, -O-,- S -, - SO ₂ -, or -C
A bond represented by an O-bond is shown. m is an integer of 1 to 150. ]

In the block copolymer, when the repeating units of the above formulas (II) and (III) are represented by II and III, respectively, III-II-III type, III-II type and II-III-II type Or a multi-block type or the like may be used. Especially,
A type III-II having a simple production process can be suitably used. Since a resin having a high total light transmittance is required, if the number n of repeating siloxane units exceeds 60, the copolymer becomes cloudy and the total light transmittance decreases, which is not suitable. Therefore, when it is 60 or less, it becomes transparent, and therefore, usually 1 to 60
, Preferably 5 to 50, more preferably 10 to 40.

The aromatic polycarbonate-polyorganosiloxane block copolymer of the present invention (the above III-II type)
Is described in JP-A-7-292113 by the present applicant. Specifically, the polycarbonate oligomer and the one-end-blocked polyorganosiloxane are separately produced, and the organic solvent is used in an amount of 0.12 to 35 parts by weight of the one-end-blocked polyorganosiloxane with respect to 100 parts by weight of the polycarbonate oligomer. And an aqueous solution of an alkali metal hydroxide of a dihydric phenol and a terminal stopper of a monohydric phenol. Further, a tertiary amine or a quaternary ammonium salt usually used as a catalyst in the production of polycarbonate is added. By performing an interfacial polycondensation reaction using such a catalyst, a polycarbonate-polyorganosiloxane block copolymer can be obtained.

A typical method for producing the above-mentioned one-terminal-blocked polyorganosiloxane is a haloformate represented by the general formula (V) based on 1 mol of the both-terminal-reactive polyorganosiloxane represented by the following formula (IV). By reacting a compound having a group or a carboxylic acid halide group, that is, a modifying agent in an amount of 0.1 mol or more and less than 2 mol, it is possible to produce a modified polyorganosiloxane having one end-capping compound represented by the formula (VI). it can.

[0016]

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[R ^{1 to} R ⁴ and Y are the same as those in the above formula (II). ]

[0018]

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[X is a halogen atom, D is a single bond or -O
-Indicates binding. R ⁷ represents a group represented by an alkyl group having 1 to 20 carbon atoms or an arylalkyl group having 7 to 20 carbon atoms. ]

[0020]

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[R ^{1 to} R ⁴ and Y are the same as in the above formula (II), and D and R ⁷ are the same as in the above formula (V). As a typical method for producing a polycarbonate oligomer, a dihydric phenol 10 represented by the following general formula (VII) is used.
A polycarbonate oligomer having formula (III) obtained by mixing and optionally reacting a catalyst such as triethylamine in a solvent such as methylene chloride at a ratio of 110 to 150 moles of phosgene to 0 moles is obtained. be able to.

[0022]

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[R ⁵ , R ⁶ , Z, p and q are represented by the above formula (III)
Is the same as). Usually, in the production of a copolymer, a homopolymer of a polycarbonate is also produced, which is substantially a mixture of the copolymer and the homopolycarbonate. In the present invention, this is referred to as an “aromatic containing a block of polyorganosiloxane. It is referred to as "polycarbonate resin" or simply "copolymer".

Other aromatic polycarbonate resins containing polyorganosiloxane blocks include graft copolymers in which polysiloxane repeating units are graft-polymerized. A typical polymer structure is composed of a polysiloxane unit represented by the formula (VIII) and a main repeating unit represented by the formula (III), and has a high degree of freedom of a siloxane molecule, and is suitable for a polymer alloy material. .

[0025]

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[R ⁵ , R ⁶ , p, and q are the same as those in the above formula (III). Z is an alkylene group, an alkylene ester group, or an alkylene carbonyl group among those shown in the above formula (III). R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are an alkyl group or an aryl group. k is 0 to 1000
It is. ]

Specifically, the polysiloxane group is polydimethylsiloxane, polydiethylsiloxane, polydiphenylsiloxane, polymethylphenylsiloxane, or the like. The dihydric phenol having an unsaturated group that reacts with polysiloxane is 4-methyl-2,4-bis (4-hydroxyphenyl) -1-pentene, 4-methyl-2,4-bis (4-hydroxyphenyl)- 2-pentene, 4,4 '
-Bis (4-hydroxyphenyl) -1-pentene,
4,4′-dihydroxychalcone, 2,2′-bis (4
-Hydroxyphenyl) -2-acryloyltan, 1,
3-bis (4-hydroxyphenyl) -2-butene-1
-ON.

[0028]

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[R ⁵ , R ⁶ , Z, p, q, and m are the same as those in the above formula (III). The graft copolymer is disclosed in JP-A-7-16589.
No. 7 is described.

(2) Aromatic polycarbonate resin containing no polyorganosiloxane block In the present invention, if necessary, a homopolymer of an aromatic polycarbonate, that is, a polyorganosiloxane block may be added to the copolymer (1). It is possible to use a mixture of aromatic polycarbonates not containing.

This aromatic polycarbonate usually has the same repeating unit as that of the above formula (III).
It can be easily produced by reacting a polyhydric phenol with a phosgene or a carbonate compound by a known method such as an interfacial polymerization method, and there is no particular limitation on raw materials, production methods and the like. Examples of dihydric phenols include hydroquinone, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl)
Alkane, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl) oxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenylsulfone, bis (4-hydroxyphenyl) ketone, 9,9 -Bis (4-hydroxyphenyl)
Examples thereof include fluorene and the like and halogen derivatives thereof. Among them, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is suitable. Examples of the carbonate compound include diaryl carbonates such as diphenyl carbonate, dialkyl carbonates such as dimethyl carbonate and dimethyl carbonate.

The terminal terminator may have any structure as long as it is a monohydric phenol, and is not particularly limited. For example, p-tert-butylphenol, p-tert-octylphenol, p-cumylphenol, phenol, p-
tert-amylphenol, p-nonylphenol, p-cresol, tribromophenol, p-bromophenol,
4-hydroxybenzophenone and the like, which may be used alone or in combination of two or more.

Further, a branching agent may be used in combination as long as the effects of the present invention are not impaired. 1,1,1-Tris as branching agent
(4-hydroxyphenyl) ethane, α, α ', α''-tris
(4-hydroxyphenyl) -1,3,5-triisopropylbenzene, 1- [α-methyl-α- (4′hydroxyphenyl) ethyl] -4- [α ′, α′-bis (4 ''- Compounds having three or more functional groups such as [hydroxyphenyl) ethyl] benzenephloroglucin, trimellitic acid, and isatin bis (o-cresol) are suitable.

(3) Aromatic polycarbonate resin composition containing a polyorganosiloxane block The aromatic polycarbonate resin containing a polyorganosiloxane block of the above (1) or an aromatic containing no block of the resin (1) and a polyorganosiloxane It may be made of a mixture with the group A polycarbonate resin (2) and blended with a kneader, or may be dry blended.

Including the case where the above mixture is used, the polyorganosiloxane content in the resin composition is as follows:
It is 0.01 to 5% by weight, preferably 0.1 to 3% by weight, and more preferably 0.3 to 1% by weight. If the polyorganosiloxane content is less than 0.01% by weight, the effect of increasing the total light transmittance and haze by the polyorganosiloxane is small, and the impact resistance is reduced. 5% by weight
If it exceeds, the total light transmittance decreases, and the heat resistance and rigidity also decrease.

The viscosity average molecular weight (Mv) of the resin composition is usually from 10,000 to 50,000, preferably from 120 to 50,000.
00 to 40,000, more preferably 14,000 to
32000. Viscosity average molecular weight (Mv) of 1000
If it is less than 0, the impact resistance is reduced, and if it exceeds 50,000, the fluidity may be reduced.

(4) Bead-shaped crosslinked acrylic resin The bead-shaped crosslinked acrylic resin used in the present invention is a copolymer obtained by adding a crosslinked monomer to an acrylic non-crosslinkable monomer and performing suspension polymerization. As the acrylic non-crosslinkable monomer, an acrylic monomer alone or a mixture of an acrylic monomer and an aromatic vinyl monomer is used. As the acrylic monomer, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethyl-hexyl acrylate,
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like can be used alone or in combination of two or more. Among them, methyl methacrylate is preferably used. Styrene, α-
Examples thereof include methylstyrene and vinyltoluene, and carboxylic acids such as fumaric acid and maleic acid in addition to these aromatic vinyl monomers.

On the other hand, a compound having two or more unsaturated bonds in a molecule is used as a crosslinking monomer. For example, allyl methacrylate, triallyl cyanurate, triallyl isocyanate, ethylene glycol dimethacrylate, propylene glycol diallyl ether, divinylbenzene, diethylene glycol dimethacrylate,
Examples include 1,6-hexanediol dimethacrylate. Among them, allyl methacrylate having at least one allyl group is preferable since a crosslinked product having excellent heat resistance can be obtained. Although the particle size of the bead-shaped crosslinked acrylic resin is not particularly limited, it is usually 0.1
品 50 μm, more preferably 1 to 10 μm. Further, the particle size distribution is preferably close to monodispersion.

(5) Light-Diffusing Resin Composition The light-diffusing resin composition of the present invention contains an aromatic polycarbonate resin (A) containing a polyorganosiloxane block or a block of the resin (A) and a polyorganosiloxane. A mixture with the aromatic polycarbonate resin (B) having a polyorganosiloxane content of 0.01
100 parts by weight of an aromatic polycarbonate-based resin composition in an amount of 0.1 to 5% by weight and a bead-like crosslinked acrylic resin 0.01 to 3
0 parts by weight.

The resin composition of the present invention is based on an aromatic polycarbonate containing a polyorganosiloxane block having a high total light transmittance and capable of forming a very bright light source.
It is composed of a bead-like crosslinked acrylic resin added as a light diffusing agent. In the light diffusion plate formed into a plate-like molded product by molding this light-diffusing resin composition, the total light transmittance is reduced even when the addition concentration of the same bead-shaped crosslinked acrylic resin increases as the plate thickness increases. That is, if the optical path length increases, the amount of absorbed light increases, and the amount of transmitted light attenuates. In practice, a resin composition having a plate thickness in the range of 0.1 to 8 mm and having high total light transmittance and high haze is desired.

According to the present invention, the thickness of the light diffusing plate is set to 0.1.
In the range of 1 to 2 mm, bead-like crosslinked acrylic resins 1 to 3
A light-diffusing resin composition to which 0 parts by weight is added is suitably used, and a light-diffusing resin composition to which 0.01 to 1 part by weight of a bead-shaped crosslinked acrylic resin is added when the plate thickness is in the range of 2 to 8 mm is preferable. Used for In the former case, when the addition concentration of the bead-like crosslinked acrylic resin exceeds 30 parts by weight, the haze no longer increases and the total light transmittance also decreases, and a desirable light diffusion plate cannot be obtained. In the latter, the amount of diffused light is effectively increased in the range of the addition concentration of the bead-shaped crosslinked acrylic resin in the range of 0.01 to 1 part by weight, and appears as an increase in haze. The increase is past the peak, and the total light transmittance is also decreasing, which is not preferable. Furthermore, the plate thickness is 8mm
When the ratio exceeds the upper limit, the upper limit of the addition amount of the bead-shaped crosslinked acrylic resin also decreases.

Further, various additives such as an antioxidant, a release agent, a weathering agent, an ultraviolet ray inhibitor, a coloring agent and the like may be blended as long as the effects of the present invention are not impaired. The light diffusing resin composition of the present invention may be compounded and kneaded in a usual manner, for example, a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw extruder, a kneader, It can be performed by a multi-screw extruder or the like. Usually, the temperature condition of kneading is suitably 280 to 320 ° C.

[0043]

The present invention will be described in more detail with reference to Examples and Comparative Examples. Example of Production of Aromatic Polycarbonate Resin Containing Polyorganosiloxane Block (1) Production of Polycarbonate Oligomer
g of bisphenol A was dissolved to prepare an aqueous solution of bisphenol A in sodium hydroxide. Then, the sodium hydroxide aqueous solution of bisphenol A kept at room temperature was introduced at a flow rate of 138 liters / hour and methylene chloride at a flow rate of 69 liters / hour through an orifice plate into a tubular reactor having an inner diameter of 10 mm and a length of 10 m. Then, phosgene was blown in parallel at a flow rate of 10.7 kg / hour, and reacted continuously for 3 hours. The tubular reactor used here was a double tube, and the outlet temperature of the reaction solution was kept at 25 ° C. by passing cooling water through the jacket. Also,
The pH of the effluent was adjusted to show 10-11. The reaction solution thus obtained was allowed to stand, whereby the aqueous phase was separated and removed, and the methylene chloride phase (220 liters) was collected.
7 g / l). Polymerization degree of the polycarbonate oligomer obtained here is 2 to 4, the concentration of chloroformate group was _0. 7N.

(2) Reactive polydimethylsiloxane (P
Synthesis of DMS) 1483 g of octamethylcyclotetrasiloxane, 9
6 g of 1,1,3,3-tetramethyldisiloxane and 35 g
Of 86% sulfuric acid and stirred at room temperature for 17 hours. Thereafter, the oil phase was separated, 25 g of sodium hydrogen carbonate was added, and the mixture was stirred for 1 hour. The mixture was filtered and vacuum distilled at 150 ° C. and 3 torr to remove low-boiling substances. 2-allylphenol and 0 of 60 g 0014G platinum chloride _-. To a mixture of platinum as alcoholate complex was added the oil obtained above in 294g at a temperature of 90 ° C.. This mixture is 90-1
The mixture was stirred for 3 hours while maintaining the temperature at 15 ° C. The product was extracted with methylene chloride and washed three times with 80% aqueous methanol to remove excess 2-allylphenol. The product was dried over anhydrous sodium sulphate and evaporated in vacuo to a temperature of 115 ° C. The obtained terminal phenol PDM
As for S, the number of repeating dimethylsilanooxy units was 30 as measured by NMR.

(3) Example of Synthesis of PC-PDMS Copolymer 91 g of reactive PDMS was dissolved in 2 liter of methylene chloride and mixed with 10 liter of polycarbonate oligomer. There, 26 g of sodium hydroxide dissolved in 1 liter of water and 5.7 cc of triethylamine were added _.
Was added and the mixture was stirred at 500 rpm for 1 hour at room temperature. Thereafter, 600 liters of bisphenol A dissolved in 5 liters of a 5.2 wt% aqueous sodium hydroxide solution, 8 liters of methylene chloride and 81 g of p-tert-butylphenol were added, and the mixture was stirred at 500 rpm for 2 hours at room temperature.
Thereafter, 5 liters of methylene chloride was added, and the mixture was further washed with 5 liters of water, washed with 5 liters of a 0.01 N aqueous sodium hydroxide solution with alkali, and washed with 5 liters of 0.1 N hydrochloric acid.
Acid washing and water washing with 5 liters of water in order, and finally methylene chloride is removed to remove the flakes of P.
A C-PDMS copolymer was obtained. PC-PDMS obtained
The copolymer was vacuum dried at 120 ° C. for 24 hours. The viscosity average molecular weight is 20100, and the PDMS content is 2.0 w
t%. PDMS content was measured by HNMR. The viscosity average molecular weight was measured at 20 ° C. using an Ubbelohde type viscosity tube.
The intrinsic viscosity [η] of the methylene chloride solution at
It was calculated by the following relational expression. [Η] = 1.23 × 10 ⁻⁵ · Mv ^0.83

Examples 1 to 7, Comparative Examples 1 to 6, Reference Example 1 The PC-PDMS copolymer obtained in the above (3) Synthesis Example of PC-PDMS copolymer, and Idemitsu Petrochemical Co., Ltd. as a polycarbonate resin Teflon FN2200A (M
v: 21000), as a bead-like crosslinked acrylic resin (A) Technopolymer MBX manufactured by Sekisui Plastics Co., Ltd.
-5 (average particle diameter 5 μm, particle diameter 5.04 to 6.35:
30%) and (B) Technopolymer MB30X-5SS (average particle size 5 μm, particle size 5.04 to 6.35: 80% or more) manufactured by Sekisui Plastics Co., Ltd., blended in the ratio shown in Table 1, Extruded at 280 ° C and pelletized. When compounding each raw material resin, etc., as an antioxidant,
500 ppm of tris (2,4-di-tert-butylphenyl) phosphite was added. Example 6 and Comparative Example 3
In addition, as a release agent, stearic acid monoglyceride 2
000 ppm was also blended. The obtained pellet is heated at 280 ° C.
And the total light transmittance and haze were measured. Table 1 shows the results. Total light transmittance and haze are JIS-K-7
105. The size of the test piece is 40 m in length.
m, width 40 mm, thickness 1 mm.

[0047]

[Table 1]

Examples 8 to 13, Comparative Example 7, and Reference Examples 2 to 3 Idemitsu Petrochemical Co., Ltd. used the PC-PDMS copolymer obtained in the above (3) Synthesis Example of PC-PDMS copolymer and polycarbonate resin. Teflon FN2200A (M
v: 21000), as a bead-like crosslinked acrylic resin (A) Technopolymer MBX manufactured by Sekisui Chemical Co., Ltd.
-5 (average particle diameter 5 μm, particle diameter 5.04 to 6.35:
30%) and (B) Technopolymer MB30X-5SS (average particle size 5 μm, particle size 5.04 to 6.35: 80% or more) manufactured by Sekisui Plastics Co., Ltd., and blended at the ratio shown in Table 2. Extruded at 280 ° C and pelletized. When compounding each raw material resin, etc., as an antioxidant,
500 ppm of tris (2,4-di-tert-butylphenyl) phosphite was added. The obtained pellet is heated at 280 ° C.
And the total light transmittance and haze were measured. Table 2 shows the results. Total light transmittance and haze are JIS-K-7
105. The size of the test piece is 40 m in length.
m, width 40 mm, thickness 3 mm.

[0049]

[Table 2]

[0050]

According to the present invention, the total light transmittance is high and the haze is well-balanced.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 33:06)

Claims (2)

[Claims] 1. An aromatic polycarbonate resin (A) containing a block of polyorganosiloxane or a mixture of the resin (A) and an aromatic polycarbonate resin (B) not containing a block of polyorganosiloxane, A light diffusing resin composition comprising 100 parts by weight of an aromatic polycarbonate resin having a siloxane content of 0.01 to 5% by weight and 0.01 to 30 parts by weight of a bead-like crosslinked acrylic resin. 2. The light diffusing resin composition according to claim 1, wherein the repeating unit of the polyorganosiloxane is represented by the formula (I). Embedded image [R ^a and R ^b are an alkyl group having 1 to 6 carbon atoms or a phenyl group, which may be the same or different. ]