JP2012014195A - Light diffusing member using light diffusing resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusing member obtained from a light diffusing resin composition that has excellent light diffusibility and high total light transmittance, suppresses discoloration during melt processing and during use, and is useful as a lighting cover, an illuminated sign, a transmissive screen, various types of display, a light diffusing sheet of a liquid crystal display device, and the like.SOLUTION: A light diffusing member contains a light diffusing resin composition that comprises 0.05 to 20 pts.wt. of organic light diffusing fine particles with weight average particle size of 0.7 to 30 μm and 0.05 to 5 pts.wt. of an ultraviolet absorber having a maximum absorption wavelength of 380 nm or less based on 100 pts.wt. of a resin component (component C) comprising 30 to 99 pts.wt. of an aromatic polycarbonate resin (component A) and 1 to 70 pts.wt. of an alicyclic polyester resin (component B).

Description

The present invention relates to a light diffusing member using a light diffusing resin composition. Specifically, it has high light diffusivity and total light transmittance, and at the same time has excellent mechanical properties, thermal properties, electrical properties, and weather resistance, and further suppresses discoloration during melt processing and use. an optical diffusing member using the composition. Specifically, the present invention relates to a light diffusing member that exhibits excellent effects when used as a light diffusing sheet for various lighting covers, lighting signs, light transmission screens, various displays, liquid crystal display devices, and the like.

  Polycarbonate resin has a wide range of uses as a thermoplastic resin excellent in impact resistance, heat resistance and transparency, and it is lighter than inorganic glass and has excellent productivity, so various lighting covers, lighting signs, It is used for light diffusing sheets such as light transmissive screens, various displays, and liquid crystal display devices.

  In order to impart light diffusibility to the polycarbonate resin, addition of inorganic compound fillers such as glass, silica and aluminum hydroxide has also been proposed, but the mechanical strength decreases, the total light transmittance and weather resistance decrease, There was a problem of discoloration at the time of molding processing or use at high temperature, and it was not practical. In particular, in recent years, in addition to the increase in size and thickness of various display devices, the luminance and light quantity of light sources have increased remarkably, and therefore, there is a strong demand for suppressing discoloration and intensity reduction due to heat and light.

  In order to meet such demands, a mixture of a specific phosphorus compound, trialkyl phosphate, pentaerythritol diphosphite compound, and hindered phenol in a mixture of aromatic polycarbonate resin and organic polymer fine particles blended at a specific ratio. A diffusible aromatic polycarbonate resin composition is disclosed (see, for example, Patent Document 1).

  The resin composition with improved weather resistance includes polycarbonate, alicyclic polyester resin, at least one UV absorber based on benzotriazole, benzophenone and triazine and a catalyst inhibitor (from the synthesis of polycarbonate and alicyclic polyester). A composition containing a substance that deactivates a residual polymerization catalyst that may remain is also disclosed (see, for example, Patent Document 2).

  On the other hand, as a resin composition excellent in transparency, impact resistance, chemical resistance, and weather resistance, a housing material made of a resin composition containing an alicyclic polyester and polycarbonate (see, for example, Patent Document 3), and electricity. Electronic parts (see, for example, Patent Document 4) have been proposed. Furthermore, it is described that such a resin composition may contain an inorganic compound such as glass fiber, carbon fiber, talc, clay, mica, glass flake, milled glass, and glass beads. However, since these resin compositions have low thermal stability during melt processing and large yellowing, it is difficult to use as a light diffusing member, and there is a description and suggestion about adaptation to such applications. It is not done.

  Moreover, optical parts (for example, refer to Patent Document 5) composed of a resin composition containing an alicyclic polyester and polycarbonate excellent in transparency, impact resistance, chemical resistance, and weather resistance, ductility, chemical resistance, and A transparent / translucent molding composition comprising a polycarbonate resin and an alicyclic polyester resin having improved melt flow characteristics has been proposed (see, for example, Patent Document 6).

JP 2001-323149 A JP-A-11-130955 JP 2003-110252 A JP 2003-113252 A JP 2003-176401 A Japanese translation of PCT publication No. 2004-514011

However, for example, the polycarbonate resin composition described in Patent Document 1 still has insufficient weather resistance, and the resin composition described in Patent Document 2 also has ultraviolet rays such as benzotriazole compounds, benzophenones, and triazine compounds. including absorbent because the initial hue is poor, it is a large light diffusing member was not suitable for use.

  And in the polycarbonate resin composition of patent document 3 and 4, since the heat stability at the time of a melt process is low and yellowing is large, there exists a problem that the use as a light-diffusing member is difficult, and such an application is used. There is no description or suggestion about the indication of.

  Moreover, about the polycarbonate resin composition of patent document 5 and 6, although addition of elastomers, such as ABS, and addition of a special effect colorant are described as an arbitrary component, these reduce haze and light transmittance. The purpose is to improve, and there is still a problem that sufficient light diffusivity cannot be obtained. Examples of these resin compositions include a (transparent) elastomer component added for the purpose of improving low-temperature impact resistance, for example. However, since the average particle size of the elastomer component is generally very small, about 100 nm, there is a problem that sufficient light diffusibility cannot be obtained.

An object of the present invention is to provide an illumination cover, an illumination signboard, a transmission screen, various displays, liquid crystal, which has excellent light diffusibility, high total light transmittance, and suppresses discoloration during melt processing and use. It is to provide a light diffusing member obtained useful light diffusing resin composition or found as a light diffusion sheet and the like of the display device.

As a result of intensive studies to solve the above problems, the present inventors have found that a resin composition in which a specific alicyclic polyester resin, a light diffusing agent, and an ultraviolet absorber are blended with an aromatic polycarbonate resin has excellent light diffusibility. In addition, the present inventors have found that the total light transmittance is high and that discoloration during melt processing and use can be suppressed, and the present invention has been completed. That is, the gist of the present invention is that, in a light diffusing member containing a light diffusing resin composition , the light diffusing resin composition comprises 30 to 99 parts by weight of an aromatic polycarbonate resin (component A) and an alicyclic polyester resin. (Component B) 0.05 to 20 parts by weight of organic light diffusing fine particles having a weight average diameter of 0.7 to 30 μm and the longest absorption with respect to 100 parts by weight of the resin component (C component) including 1 to 70 parts by weight A light diffusing member comprising 0.05 to 5 parts by weight of an ultraviolet absorber having a wavelength of 380 nm or less .

The light diffusing resin composition in the present invention has light diffusibility, high total light transmittance, and discoloration at the time of melt processing or use is suppressed . The light diffusing member can be widely used for applications requiring light diffusibility, such as lighting covers, lighting signs, transmissive screens, traffic light lenses and lens covers, various displays, light diffusing sheets for liquid crystal display devices, and light guide plates.

Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
In the present specification, the “group” of various compounds may have a substituent without departing from the gist of the present invention.

[1] Aromatic polycarbonate resin (component A)
The component A in the present invention is (A) an aromatic polycarbonate resin, for example, a linear chain obtained by reacting an aromatic dihydroxy compound and a carbonate precursor, or a small amount of a polyhydroxy compound in combination with these compounds. Or a branched thermoplastic aromatic polycarbonate polymer or copolymer.

  The (A) aromatic polycarbonate resin in the present invention is not particularly limited and can be produced by a known method, for example, an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring opening of a cyclic carbonate compound. Examples thereof include a polymerization method and a solid phase transesterification method of a prepolymer.

  As aromatic dihydroxy compounds used as raw materials, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane (= Tetrabromobisphenol A), bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxy) Phenyl) octane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (3-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-) 3,5-dimethylphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2- (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, , 1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxyphenyl) -1,1,1-trichloropropane, 2,2- Bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexachloropropane, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane Bis (hydroxyaryl) alkanes exemplified by the above; 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxy) Roxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and the like bis (hydroxyaryl) cycloalkanes; 9,9-bis (4-hydroxyphenyl) Cardo structure-containing bisphenols exemplified by fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene; 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyl Dihydroxy diaryl ethers exemplified by diphenyl ether and the like; dihydroxy diaryl sulfides exemplified by 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide and the like; 4,4′- Dihydroxydiphenyl sulfoxide, Dihydroxydiaryl sulfoxides exemplified by 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide and the like; 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone and the like Exemplified dihydroxydiaryl sulfones; hydroquinone, resorcin, 4,4′-dihydroxydiphenyl and the like.

Among these, bis (4-hydroxyphenyl) alkanes are preferable, and 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A] is particularly preferable from the viewpoint of impact resistance.
These aromatic dihydroxy compounds may be used alone or in combination of two or more.

  As the carbonate precursor to be reacted with the aromatic dihydroxy compound, carbonyl halide, carbonate ester, haloformate and the like are used. Specifically, phosgene; diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dimethyl carbonate, diethyl carbonate And dialkyl carbonates such as dihaloformates of dihydric phenols. These carbonate precursors may also be used alone or in combination of two or more.

  The (A) aromatic polycarbonate resin may be a branched aromatic polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound. Examples of the trifunctional or higher polyfunctional aromatic compound include phloroglucin, 4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-2, 4,6-dimethyl-2,4,6- Tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3, 1,3,5-tri (4-hydroxyphenyl) benzene, 1, Polyhydroxy compounds exemplified by 1,1-tri (4-hydroxyphenyl) ethane or the like, or 3,3-bis (4-hydroxyaryl) oxindole (= isatin bisphenol), 5-chloroisatin, 5, Examples thereof include 7-dichloroisatin and 5-bromoisatin. Among these, 1,1,1-tri (4-hydroxyphenyl) ethane is preferable. The polyfunctional aromatic compound can be used by replacing a part of the aromatic dihydroxy compound, and the amount used is preferably in the range of 0.01 to 10 mol% with respect to the aromatic dihydroxy compound. The range of .1 to 2 mol% is more preferable.

In the reaction by the interfacial polymerization method, the pH is usually kept at 9 or higher in the presence of an organic solvent inert to the reaction and an aqueous alkaline solution, and the aromatic dihydroxy compound, and the molecular weight adjusting agent (end terminator) and aromatic as necessary. After reacting with phosgene using an antioxidant for preventing oxidation of the group dihydroxy compound, a polymerization catalyst such as a tertiary amine or a quaternary ammonium salt is added and interfacial polymerization is performed to obtain a polycarbonate. The addition of the molecular weight regulator is not particularly limited as long as it is from the time of phosgenation to the start of the polymerization reaction. The reaction temperature is, for example, 0 to 40 ° C., and the reaction time is, for example, several minutes (for example, 10 minutes) to several hours (for example, 6 hours).
Here, examples of the organic solvent inert to the reaction include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene and dichlorobenzene, and aromatic hydrocarbons such as benzene, toluene and xylene. . Examples of the alkali compound used in the alkaline aqueous solution include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.
Examples of the molecular weight regulator include compounds having a monovalent phenolic hydroxyl group. Examples of the compound having a monovalent phenolic hydroxyl group include m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol and p-long chain alkyl-substituted phenol. The amount of the molecular weight regulator used is preferably 50 to 0.5 mol, more preferably 30 to 1 mol, per 100 mol of the aromatic dihydroxy compound.
Polymerization catalysts include tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine, trihexylamine and pyridine: quaternary ammonium salts such as trimethylbenzylammonium chloride, tetramethylammonium chloride, triethylbenzylammonium chloride Etc.

The reaction by the melt transesterification method is, for example, a transesterification reaction between a carbonic acid diester and an aromatic dihydroxy compound.
Examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate and di-tert-butyl carbonate, and substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate. The carbonic acid diester is preferably diphenyl carbonate or substituted diphenyl carbonate, more preferably diphenyl carbonate.
Generally, a polycarbonate having a desired molecular weight and a terminal hydroxyl group amount can be obtained by adjusting the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound or adjusting the degree of vacuum during the reaction. As a more aggressive method, an adjustment method in which a terminal terminator is added separately during the reaction is also well known. In this case, examples of the terminal terminator include monohydric phenols, monovalent carboxylic acids, and carbonic acid diesters. The amount of terminal hydroxyl groups greatly affects the thermal stability, hydrolysis stability, color tone, etc. of the product polycarbonate. Although it depends on the application, in order to have practical physical properties, it is preferably 1,000 ppm or less, more preferably 700 ppm or less.
Moreover, in the polycarbonate manufactured by the transesterification method, it is preferable that the amount of terminal hydroxyl groups is 100 ppm or more. By setting it as the amount of such terminal hydroxyl groups, the fall of molecular weight can be suppressed and a color tone can also be made more favorable. Accordingly, it is preferable to use an equimolar amount or more of the carbonic acid diester, and more preferably 1.01 to 1.30 mol, per 1 mol of the aromatic dihydroxy compound.
When producing a polycarbonate by the transesterification method, a transesterification catalyst is usually used. The transesterification catalyst is not particularly limited, but an alkali metal compound and / or an alkaline earth metal compound is preferable. In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound can be used in combination. As the transesterification reaction using the above raw materials, the reaction is carried out at a temperature of 100 to 320 ° C., and finally a melt polycondensation reaction is performed under reduced pressure of 2 mmHg or less while removing by-products such as aromatic hydroxy compounds. The method of performing is illustrated.
The melt polycondensation can be carried out batchwise or continuously, but is preferably carried out continuously in view of the stability of the resin composition of the present invention. As the catalyst deactivator in the transesterification polycarbonate, it is preferable to use a compound that neutralizes the catalyst, for example, a sulfur-containing acidic compound or a derivative formed therefrom. The compound that neutralizes such a catalyst is preferably added in an amount of 0.5 to 10 equivalents, more preferably 1 to 5 equivalents, relative to the alkali metal contained in the catalyst. In addition, the compound that neutralizes such a catalyst is preferably added in an amount of 1 to 100 ppm, more preferably 1 to 20 ppm, based on the polycarbonate.

  The molecular weight of the aromatic polycarbonate resin used in the present invention is not particularly defined, but a viscosity average molecular weight [Mv] converted from the solution viscosity is preferably in the range of 10,000 to 50,000. By setting the viscosity average molecular weight of the aromatic polycarbonate to 10,000 or more, the mechanical strength tends to be further improved, and the aromatic polycarbonate is more preferable for use in applications requiring high mechanical strength. On the other hand, when the viscosity average molecular weight is less than 50,000, it tends to be possible to improve the decrease in fluidity, which is more preferable from the viewpoint of easy molding processability. The viscosity average molecular weight is more preferably 12,000 to 40,000, still more preferably 14,000 to 30,000. Moreover, you may mix 2 or more types of aromatic polycarbonate resin from which a viscosity average molecular weight differs. Of course, you may mix the aromatic polycarbonate resin whose viscosity average molecular weight is outside the said suitable range.

Here, the viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and obtaining an intrinsic viscosity [η] (unit: dl / g) at a temperature of 20 ° C. using an Ubbelohde viscometer. , Η = 1.23 × 10 ⁻⁴ M ^0.83 . Here, the intrinsic viscosity [η] is a value calculated from the following equation by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

  Further, in order to improve the appearance of the molded product and the fluidity, the (A) aromatic polycarbonate resin in the present invention may contain an aromatic polycarbonate oligomer. The aromatic polycarbonate oligomer has a viscosity average molecular weight [Mv] of preferably 1,500 to 9,500, more preferably 2,000 to 9,000. The aromatic polycarbonate oligomer is preferably used in the range of 30% by weight or less of the component A.

  Furthermore, the (A) aromatic polycarbonate resin in the present invention may use not only a virgin raw material but also an aromatic polycarbonate resin regenerated from a used product, that is, a so-called material recycled aromatic polycarbonate resin. 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 bottle containers, glasses lenses, soundproof walls, glass windows, waves, etc. A building member such as a plate is preferred. Also, non-conforming products, pulverized products obtained from sprues, runners, etc., or pellets obtained by melting them can be used. The regenerated aromatic polycarbonate resin is preferably 80% by weight or less, more preferably 50% by weight or less of the component A.

The alicyclic polyester resin according to the present invention is a polyester resin obtained by reacting a dicarboxylic acid component mainly composed of 1,4-cyclohexanedicarboxylic acid with a diol component.
In other words, the alicyclic polyester resin according to the present invention is obtained by using a dicarboxylic acid component as a raw material, so that the alkyl ester terminal is different from the case of using a dicarboxylic acid ester as a raw material. The alicyclic polyester resin is small, that is, the ratio of the alkyl ester terminal to the total terminal of the polyester is 5 mol% or less, preferably 1 mol% or less.

[2] Alicyclic polyester resin (component B)
The B component in the present invention is (B) an alicyclic polyester resin. For example, a dicarboxylic acid component, a diol component, and optionally a small amount of other components are esterified or transesterified, It is formed by polycondensation reaction. The dicarboxylic acid component is mainly composed of an alicyclic dicarboxylic acid or an ester-forming derivative thereof. Moreover, a diol component has alicyclic diol as a main component.
Here, the “main component” means, for example, that each occupies 80 mol% or more with respect to the dicarboxylic acid component or the diol component.

The alicyclic dicarboxylic acid or an ester-forming derivative thereof is not particularly limited as long as two carboxyl groups are bonded to the alicyclic structure. Specifically, for example, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-decahydronaphthalenedicarboxylic acid, 1,5-decahydronaphthalenedicarboxylic acid, Examples include 2,6-decahydronaphthalenedicarboxylic acid, 2,7-decahydronaphthalenedicarboxylic acid, and ester-forming derivatives thereof.
Among these, alicyclic dicarboxylic acids having 6 to 12 carbon atoms or ester-forming derivatives thereof are preferable, 1,4-cyclohexanedicarboxylic acid or ester-forming derivatives thereof are more preferable, and 1,4-cyclohexanedicarboxylic acid is further preferable. An alicyclic dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid is preferable because it is less expensive than an ester-forming derivative.
When 1,4-cyclohexanedicarboxylic acid is employed, the ratio of the trans isomer to the cis isomer is preferably 80/20 to 100/0, more preferably 85/15 to 100/0, even more preferably. Is 90/10 to 100/0, particularly preferably 95/5 to 100/0. By making it in such a range, the heat resistance of the alicyclic polyester resin obtained can be made more favorable.

  The dicarboxylic acid component of the (B) alicyclic polyester resin in the present invention contains alicyclic dicarboxylic acid or an ester-forming derivative thereof at 80 mol% or more, preferably 90 mol% or more, based on the total dicarboxylic acid component. To do. Other dicarboxylic acid components include aromatic dicarboxylic acids and aliphatic dicarboxylic acids. Specifically, terephthalic acid, phthalic acid, isophthalic acid, 1,4-phenylenedioxydicarboxylic acid, 1,3-phenylenedioxydiacetic acid, 4,4-diphenyldicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid 4,4-diphenyl ketone dicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, 4,4-diphenylsulfone dicarboxylic acid, aromatic dicarboxylic acid such as 2,6-naphthalenedicarboxylic acid, succinic acid, glutamic acid, Examples thereof include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecadicarboxylic acid and dodecadicarboxylic acid, and alkyl esters or halides having 1 to 4 carbon atoms.

The alicyclic diol component is not particularly limited as long as it has two hydroxyl groups bonded to the alicyclic structure, but the alicyclic diol has two hydroxyl groups bonded to a five-membered or six-membered ring. It is preferable that By using a 5-membered or 6-membered alicyclic diol as the alicyclic diol, the heat resistance of the resulting polyester resin can be increased.
Examples of such alicyclic diols include 5-membered members such as 1,2-cyclopentanedimethanol, 1,3-cyclopentanedimethanol, bis (hydroxymethyl) tricyclo, and [5.2.1.0] decane. Ring diol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2, And 6-membered ring diols such as 2-bis (4-hydroxycyclohexyl) -propane. Among these, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol and 1,4-cyclohexanedimethanol are preferable, and 1,4-cyclohexanedimethanol is more preferable.
1,4-Cyclohexanedimethanol is highly reactive because the methylol group is in the para position, it is easy to obtain a high polymerization degree polyester, a polyester resin having a high glass transition temperature is obtained, and it is an industrial product and is available. Has the advantage of being easy. The ratio of 1,4-cyclohexanedimethanol trans isomer to cis isomer is preferably in the range of 60/40 to 100/0.

In the present invention, the diol component contains an alicyclic diol as described above in an amount of 80 mol% or more, preferably 90 mol% or more based on the total diol component. Examples of other diol components include aliphatic diols and aromatic diols. When the alicyclic diol is less than 80 mol%, the compatibility with the aromatic polycarbonate resin is inferior, the transparency is lowered, and the heat resistance may be inferior.
Specific examples of other diol components include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, pentanediol, and hexanediol, and xylylene glycol, 4,4-dihydroxybiphenyl, 2,2-bis (4 And aromatic diols such as' -hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfone and bis (4-β-hydroxyethoxyphenyl) sulfonic acid.

Furthermore, the (B) alicyclic polyester resin in the present invention may contain a small amount of a copolymer component other than the diol component and the dicarboxylic acid component. Examples of such copolymer components include glycolic acid, p-hydroxybenzoic acid, hydroxycarboxylic acids such as p-β-hydroxyethoxybenzoic acid, alkoxycarboxylic acids, stearyl alcohol, benzyl alcohol, stearic acid, behenic acid, benzoic acid. Monofunctional components such as tert-butylbenzoic acid and benzoylbenzoic acid, tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetetracarboxylic acid, gallic acid, trimethylolethane, trimethylolpropane, glycerol, penta Trifunctional or higher polyfunctional components such as erythritol and sugar ester may be used.
These components are preferably 10 mol% or less of the B component.

  In the present invention, as a use ratio in the esterification reaction or transesterification reaction between the dicarboxylic acid component and the diol component, the total amount of the diol component is 1 to 2 times in molar ratio to the total amount of the dicarboxylic acid component. Is preferred. In particular, when the main component is a diol component having a high boiling point such as 1,4-cyclohexanedimethanol, the molar ratio is preferably 1 to 1.2 times.

  In the present invention, it is preferable to use a catalyst in order to obtain a sufficient reaction rate in the esterification or transesterification reaction and the polycondensation reaction. Such a catalyst is not particularly limited as long as it is a catalyst usually used for esterification or transesterification, and widely known catalysts can be employed. Specific examples include titanium compounds, germanium compounds, antimony compounds, and tin compounds. Of these, titanium compounds are preferred because of their high activity in both the esterification or transesterification reaction and the subsequent polycondensation reaction. Examples of such titanium compounds include tetra-n-propyl titanate, tetra-iso-propyl titanate, tetra-n-butyl titanate, and hydrolysates of these organic titanates. These may be used alone or in combination of two or more. Moreover, you may combine with a magnesium compound, a phosphorus compound, etc. as needed. The amount of the catalyst used is preferably 1 to 2000 ppm, more preferably 10 to 1000 ppm, still more preferably 50 to 1000 ppm, and particularly preferably 100 to 1000 ppm with respect to the (B) alicyclic polyester resin to be produced.

The esterification reaction or transesterification reaction between the dicarboxylic acid component and the diol component is usually carried out at 150 to 230 ° C., preferably 180 to 220 ° C., usually for 10 minutes to 10 hours, preferably 30 minutes to 5 hours.
After the esterification reaction, the reaction solution is usually transferred to a polycondensation tank equipped with a stirrer, a distilling tube and a vacuum addition apparatus. The esterification reaction tank is equipped with a vacuum addition apparatus, and the esterification reaction and A polycondensation reaction can also be performed.

After the esterification is completed, a polycondensation catalyst or the like is added to the reaction solution as necessary, and a polycondensation reaction is performed while gradually reducing the pressure in the reaction vessel. When the polymerization catalyst is added, the amount thereof is a total amount with the esterification reaction or transesterification reaction catalyst, and is a total amount of 50 to 2000 ppm, preferably 100 to 1000 ppm with respect to the polyester that is usually produced.
The polycondensation is carried out at an esterification reaction completion temperature of not higher than 300 ° C., preferably not higher than 265 ° C., usually for 10 minutes to 10 hours, preferably 30 minutes to 5 hours. If the temperature is too high, the polymerization reaction tends not to proceed because thermal decomposition occurs during the polymerization reaction. The pressure in the tank is a pressure that finally becomes 1 KPa or less from normal pressure, and is preferably 0.5 KPa or less.

The intrinsic viscosity of the (B) alicyclic polyester resin in the present invention is preferably 0.4 to 1.5 dl / g, more preferably 0.5 to 1.3 dl / g, and even more preferably 0.6 to 1.5 dl / g. In particular, it is preferably 0.7 to 1.4 dl / g. By setting the intrinsic viscosity to 0.4 dl / g or more, the mechanical strength is further improved, and by setting the intrinsic viscosity to 1.5 dl / g or less, the fluidity is further improved and molding becomes more preferable. Furthermore, the obtained polyester resin may be subjected to solid phase polymerization as necessary to have a higher intrinsic viscosity.
Here, intrinsic viscosity is calculated | required by measuring at 30 degreeC using a Ubbelohde viscometer by making a phenol / tetrachloroethane (weight ratio 1/1) liquid mixture into a solvent.

  The terminal carboxylic acid concentration of the (B) alicyclic polyester resin in the present invention is preferably 70 μeq / g or less, particularly 40 μeq / g or less, more preferably 30 μeq / g or less, and particularly preferably 10 μeq / g or less. preferable. It is preferable that the terminal carboxylic acid concentration be 70 μeq / g or less because the heat and humidity resistance of the resin composition of the present invention tends to be further improved.

  The terminal acid value is controlled by, for example, controlling the use ratio of 1,4-cyclohexanedicarboxylic acid and 1,4-cyclohexanedimethanol, which are raw materials, or alkylene diol, This can be carried out by using an alkylene diol having 2 to 10 carbon atoms in combination.

Moreover, in order to set the terminal acid value of the alicyclic polyester resin according to the present invention to 40 μeq / g, for example, a dicarboxylic acid component in which 90 mol% or more is 1,4-cyclohexanedicarboxylic acid, and 90 mol% or more When the diol component is 1,4-cyclohexanedimethanol, the ratio of the diol component to 1 mol of the dicarboxylic acid component is 1.02 to 1.2 mol, more preferably 1.02 to 1.1 mol. To do.
Further, for example, a dicarboxylic acid component in which 90 mol% or more is 1,4-cyclohexanedicarboxylic acid, 80 to 99.5 mol% is 1,4-cyclohexanedimethanol, and 0.5 to 20 mol% is carbon number. In the case of using 2 to 10 alkylene diols, a method of using 1.02 to 1.2 mol, more preferably 1.02 to 1.1 mol of the diol component with respect to 1 mol of the dicarboxylic acid component can be mentioned.

  The melting point of the (B) alicyclic polyester resin in the present invention is, for example, an alicyclic ring containing 1,4-cyclohexanedicarboxylic acid as a main component as a dicarboxylic acid component and 1,4-cyclohexanedimethanol as a main component as a diol component. In the case of a formula polyester resin, it is preferably 200 to 250 ° C, more preferably 210 to 230 ° C, still more preferably 215 to 230 ° C.

In the alicyclic polyester resin used in the present invention, if the Yellowness Index (YI) is too high to recognize yellow coloring even when visually observed, naturally, when used in the light diffusible resin composition of the present invention, The recorded image turns yellow and the original image cannot be reproduced. Therefore, generally YI is preferably 18 or less, more preferably 15 or less. The lower limit of YI is usually about -5.
When the light transmittance of the 2 mm-thick molded plate molded using the alicyclic polyester resin according to the present invention is too low, the light diffusing member does not sufficiently transmit light and the screen becomes dark. In some cases, the light transmittance is usually 87% or more, preferably 87.5% or more, and more preferably 88% or more.

As 1,4-cyclohexanedicarboxylic acid, which is a raw material for the alicyclic polyester resin used in the present invention, a large light transmittance at a wavelength of 340 nm is preferable from the viewpoint of the light transmittance of the obtained alicyclic polyester resin. . When this light transmittance is too low, the YI value of the resulting alicyclic polyester resin tends to increase, and the light transmittance of the alicyclic polyester resin tends to decrease. Specifically, as this light transmittance, the light transmittance measured by the following method (hereinafter sometimes abbreviated as T-340) is preferably 85% or more, more preferably 87% or more.
This T-340 was measured by using a spectrophotophotometer to put a 2N potassium hydroxide solution into a quartz cell having an optical path length of 10 mm, zero correction, and 1 for 50 ml of 2N potassium hydroxide solution. , 4-cyclohexanedicarboxylic acid dissolved in a proportion of 5.0 g in a quartz cell having an optical path length of 10 mm, and the light transmittance at a wavelength of 340 nm measured for the liquid.

  In addition, in the raw material of the alicyclic polyester resin used in the present invention, as a method for producing a raw material 1,4-cyclohexanedicarboxylic acid having a trans isomer of 90 mol% or more, for example, a cis isomer of 1,4-cyclohexanedicarboxylic acid, or Examples thereof include a thermal isomerization method of a mixture of a cis isomer and a trans isomer. In the known crystallization method using the difference in solubility between cis and trans isomers in water, the obtained 1,4-cyclohexanedicarboxylic acid has a low T-340, and the light transmittance of the resulting alicyclic polyester resin is low. Is insufficient. Therefore, the thermal isomerization method is preferable from the viewpoint that it is preferable to use 1,4-cyclohexanedicarboxylic acid having a trans isomer ratio of 90 mol% or more and T-340 of 85% or more.

  The thermal isomerization is carried out by adding a mixture of cis-1,4-cyclohexanedicarboxylic acid and trans-1,4-cyclohexanedicarboxylic acid or cis-1,4-cyclohexanedicarboxylic acid at 180 ° C. in an inert atmosphere. The heat treatment can be performed in the temperature range below the melting point of trans-1,4-cyclohexanedicarboxylic acid. The melting point of trans-1,4-cyclohexanedicarboxylic acid in the present invention refers to the melting point of trans-1,4-cyclohexanedicarboxylic acid under the actual isomerization reaction conditions.

The thermal isomerization reaction pressure can be carried out under reduced pressure, normal pressure or increased pressure, but is usually 1.3 to 950 kPa in view of the ease of operation.
Furthermore, in order to make T-340 of 1,4-cyclohexanedicarboxylic acid 85% or more, a mixture of cis / trans-1,4-cyclohexanedicarboxylic acid or cis-1,4-cyclohexanedicarboxylic acid is heat-treated. It is preferable to adjust the inert atmosphere at the time of oxygen concentration in the reaction system to 4000 ppm or less, preferably 2000 ppm or less, more preferably 1000 ppm or less. If the oxygen concentration in the system is higher than 4000 ppm, T-340 tends to be less than 85%.

In order to efficiently obtain trans-1,4-cyclohexanedicarboxylic acid produced by thermal isomerization, trans-1,4-cyclohexanedicarboxylic acid is melted in the melted cis-1,4-cyclohexanedicarboxylic acid while maintaining the temperature range. There is a method in which cyclohexanedicarboxylic acid is precipitated and removed.
In addition, what is necessary is just to obtain the method of obtaining the mixture of cis-form and trans-form 1,4-cyclohexanedicarboxylic acid used as the raw material in a thermal isomerization method by a conventionally well-known arbitrary method. For example, liquid phase nuclear hydrogenation of terephthalic acid in the presence of solvent, hydrogen and hydrogenation catalyst, and acid precipitation after liquid phase nuclear hydrogenation of sodium terephthalate in the presence of water, hydrogen and hydrogenation catalyst Is mentioned.

Further, the alicyclic polyester resin used in the present invention may be made into a pellet and then subjected to solid phase polymerization as necessary to have a higher intrinsic viscosity.
The alicyclic polyester resin used in the present invention is preferably one in which 80 mol% or more of diol units is 1,4-cyclohexanedimethanol from the viewpoint of heat resistance of the polyester resin.
Also, 80 mol% or more and 99.5 mol% or less of diol units are 1,4-cyclohexanedimethanol units, and 0.5 mol% or more and 20 mol% or less are alkylene diol units having 2 to 10 carbon atoms. Among them, those in which 1,4-cyclohexanedimethanol units are 90 mol% or more and 99.5 mol% or less, and alkylene diol units having 2 to 10 carbon atoms are 0.5 mol% or more and 10 mol% or less. It is preferable because of its high hydrolysis resistance.

[3] Resin component (C component) The resin component (C component) used in the present invention is 30 to 99 parts by weight of the above-described aromatic polycarbonate resin (A component) and 1 to alicyclic polyester resin (B component). 70 parts by weight are included. When the aromatic polycarbonate resin is less than 30 parts by weight, the load deflection temperature and rigidity are low, and when it exceeds 99 parts by weight, the effect of improving fluidity and weather resistance is small.

The fine particles used in the present invention have a weight average diameter of 0.7 to 30 μm. If the weight average diameter of the fine particles used in the present invention is less than 0.7 μm, the light diffusibility is low and the light source may be seen through. On the contrary, if it exceeds 30 μm, the surface of the molded article is noticeable and the visibility is reduced. There are things to do.
Further, the absolute value of the difference in refractive index between the fine particles used in the present invention and the resin component (C) may be appropriately selected and determined. However, if it is too small, the light diffusibility may be lowered, and conversely it is too large. However, since the light transmittance may be lowered, it is usually preferably 0.01 or more and 0.2 or less.
Further, in order for the light diffusing resin composition of the present invention to have excellent light diffusibility, total light transmittance, and discoloration resistance at the time of melt processing or use, the fine particles used in the present invention are organic light diffusing fine particles. is there. Specifically, for example, it is preferably selected from acrylic and silicone light diffusing fine particles.

  Examples of the acrylic light diffusing fine particles include fine particles obtained by changing the copolymerization ratio of the acrylic monomer alone or the acrylic monomer and the styrene monomer, and polymerizing by a suspension polymerization method using a crosslinking agent. . By changing the copolymerization ratio of the acrylic monomer and the styrene monomer in the range of 100: 0 to 1:99, the refractive index of the obtained polymer changes in the range of 1.493 to 1.590, Normally, if the copolymerization ratio of the styrene monomer is too high, the light resistance is lowered, and it tends to be yellowish during use. Conversely, if the copolymerization ratio of the acrylic monomer is too high, the fine particles and the resin The difference in refractive index from the component (C component) is too wide, so that glare is noticeable and visibility may be lowered. Therefore, when the acrylic-styrene copolymer fine particles are used as the fine particles used in the present invention, the aromatic polycarbonate resin (A component) and the alicyclic polyester resin (B component) constituting the resin component (C component). It is preferable to adjust the refractive index of the acrylic-styrene copolymer fine particles according to the blending ratio.

  Examples of the acrylic monomer include, for example, methacrylate monomers such as methyl methacrylate and ethyl methacrylate, acrylate monomers such as methyl acrylate and ethyl acrylate, acrylamide, and the like. Representative examples of the acrylic monomer include styrene, α- Typical examples thereof include methylstyrene and vinyltoluene. In the polymerization or copolymerization of these monomers, other monomers can be copolymerized as necessary with these as the main components. As the crosslinking agent, various polyfunctional monomers such as ethylene glycol dimethacrylate, divinylbenzene, 1,6-hexanediol, trimethylpropane trimethacrylate, trimethylpropane trimethacrylate, and trimethylpropane triacrylate can be generally used. .

  When silicone-based light diffusing fine particles are used as the fine particles used in the present invention, for example, silicone resin fine particles having a refractive index of 1.45 to 1.46 are preferable. Examples of commercially available silicone-based light diffusing fine particles include Tospearl series manufactured by Toshiba Silicone, Toray Fill series manufactured by Toray Dow Corning Silicone, and silicone powder manufactured by Shin-Etsu Chemical Co., Ltd.

In the present invention, the content of the organic light-diffusing fine particles having a weight average diameter of 0.7~30μm a resin component (C component) relative to 100 parts by weight, 0.05 to 10 parts by weight, preferably 0. 1 to 10 parts by weight. If the content of the fine particles is less than 0.05 parts by weight, the light diffusibility is low, and even if the light diffusing member is thick, the light source may be seen through. Even if the thickness of the conductive member is thin, the total light transmittance may decrease, and further, the mechanical strength and heat resistance may decrease.
The content of the organic light-diffusing fine particles in the light diffusing resin composition of the present invention is preferably adjusted in response to changes in the thickness of the light diffusing member. Specifically, for example, the thickness of the light diffusing member is in the case of 0.1~2mm shall be 1-10 by weight parts of the content resin component (C component) relative to 100 parts by weight of the fine particles It is preferable. When the thickness of the light diffusing member is more than 2 mm and not more than 5 mm, specifically, acrylic-styrene copolymer fine particles are used, and the content with respect to 100 parts by weight of the resin component (C component) is set to 0. It is preferable to set it as 05-5 weight part.

The light diffusing resin composition of the present invention preferably contains an ultraviolet absorber having a longest absorption wavelength of 380 nm or less in order to further improve the weather resistance.
Here, the “longest absorption wavelength” indicates the longest wavelength that exhibits substantial absorption, and the wavelength that exhibits substantial absorption indicates an absorbance of 1% or more of the absorbance at the maximum absorption wavelength of the ultraviolet absorbent. Say the wavelength. Moreover, what does not impair the characteristic of an aromatic polycarbonate is preferable.
Among them, as the ultraviolet absorber used in the present invention, malonic acid ester compounds, cyanoacrylate compounds, benzoxazine compounds, hindered benzoates are used in order to achieve both excellent light resistance, hue and high light transmittance. It is preferable to use a compound. Among them, it is preferable to use a malonic acid ester compound or a cyanoacrylate compound from the viewpoint of suppressing discoloration during melt processing and simultaneously satisfying excellent light discoloration resistance and high light transmittance.

Examples of the malonic acid ester compounds include 2- (1-arylalkylidene) malonic acid esters. Specifically, PR-25 (longest absorption wavelength: 360 nm), B-CAP (longest absorption wavelength: 365 nm). Examples include those manufactured by Clariant Japan.
Examples of hindered benzoates include 3,5-di-t-butyl-4-hydroxybenzoic acid, n-hexadecyl ester, and the like. Specifically, UV-2908 (longest absorption wavelength: 290 nm) Cytec・ Industry's product etc. are mentioned. Can be mentioned.
In particular, those having a longest absorption wavelength of 300 nm or more are preferable because of their high ultraviolet absorption effect. As such a thing, the above-mentioned malonic acid ester etc. are mentioned, for example.
The absorbance in the present invention was measured using a UV3100 manufactured by Shimadzu Corporation as a measuring instrument, using a cell with an optical path length of 1 cm as measurement conditions, and cyclohexane having a concentration of 10 mg / l by dissolving a sample (ultraviolet absorber) in cyclohexane. Use the absorbance measured for the solution. In addition, the light absorbency was calculated | required by the following general formula (1).
Absorbance: A = log ₁₀ (l ₀ / l) (1)
(However, l ₀ indicates the transmitted light intensity of the cell (without the contents), and l indicates the transmitted light intensity of the cell containing the sample.)

  Examples of the cyanoacrylate compounds include ethyl-2-cyano-3,3-diphenyl acrylate, methyl-2-cyano-3,3-diphenyl acrylate, and the like, among which ethyl-2-cyano-3,3-diphenyl acrylate Is preferred. Specifically, as 2′-ethylhexyl-2-cyano-3,3-diphenyl acrylate, Uvinul 3030, Uvinul 3035, Uvinul 3039 (all manufactured by BASF Corporation), ethyl-2-cyano-3 , 3-diphenyl acrylate includes SEESORB501 (manufactured by Cypro Kasei Co., Ltd.), and 2′-ethylhexyl-2-cyano-3,3-diphenyl acrylate includes SEESORB 502 (manufactured by Cypro Chemical Co., Ltd.)

  Content of the ultraviolet absorber used for this invention is 0.05-5 weight part with respect to 100 weight part of resin components (C component), Preferably it is 0.1-3 weight part. If the blending ratio of the UV absorber is less than 0.05 parts by weight, the improvement effect is small, and even if it exceeds 5 parts by weight, no further effect can be obtained, and mold deposit may occur.

The light diffusing resin composition of the present invention preferably contains a fluorescent dye in order to improve the brightness of the molded product. Specifically, the fluorescent dye is, for example, a white or blue fluorescent dye, and has a function of eliminating the yellowishness of the molded product and increasing the brightness. The function is similar to the bluing agent in terms of eliminating the yellowness of the molded product, but the bluing agent simply removes the yellow light of the molded product, whereas the fluorescent whitening agent has a wavelength of less than 400 nm. It differs in that it absorbs ultraviolet rays and changes its energy into visible light having a wavelength of 400 nm or more, particularly blue-violet light.
As the white or blue fluorescent dye used in the present invention, any conventionally known fluorescent dye can be used. Among them, those having a high molecular weight are preferable from the viewpoint of heat resistance and volatile gas, and examples thereof include stilbene benzoxazole-based and phenylallyltriazolyl coumarin-based fluorescent brighteners.

  The content of the fluorescent dye may be appropriately selected and determined. However, if the content of the fluorescent dye is too low, the yellowing of the molded product is erased and the brightness is increased, and the visible region absorbs ultraviolet rays. The function of radiating blue-violet is not sufficiently exhibited. On the other hand, even if it is too much, an increase in the effect commensurate with the increase in the amount added cannot be expected. Therefore, it is preferable that it is 0.00001-1 weight part normally with respect to 100 weight part of resin components (C component).

  In the present invention, it is preferable to add a phosphorous heat stabilizer in order to improve the light transmittance and hue of the light diffusing resin composition. As the phosphorus-based heat stabilizer, phosphite ester, phosphate ester and the like are preferable. Examples of the phosphite include triphenyl phosphite, trisnonylphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, trinonyl phosphite, tridecyl phosphite, and trioctyl. Phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tricyclohexyl phosphite, monobutyl diphenyl phosphite, monooctyl diphenyl phosphite, distearyl pentaerythritol diphosphite, bis (2,4-di -Tert-butylphenyl) pentaerythritol phosphite, bis (2.6-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite, 2,2-methylenebis (4,6-di-t rt- butylphenyl) triesters of phosphorous acid such as octyl phosphite, diesters, monoesters, and the like.

  Examples of the phosphoric acid ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, 2-ethylphenyldiphenyl phosphate, tetrakis (2,4- And di-tert-butylphenyl) -4,4-diphenylene phosphonite.

  Among the above phosphorus-based heat stabilizers, distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol phosphite, bis (2.6-di-tert-butyl-4) -Methylphenyl) pentaerythritol phosphite and tris (2,4-di-tert-butylphenyl) phosphite are preferred. Among them, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite and Tris (2,4-di-t-butylphenyl) phosphite is particularly preferred. In addition, a phosphorus heat stabilizer may be used independently and may be used in combination of 2 or more type.

  The content of the phosphorus-based heat stabilizer used in the present invention may be appropriately selected and determined. However, if the content is too small, the effect as a heat stabilizer is small. In addition to the expectation of an increase in commensurate effect, hydrolysis may easily occur. Therefore, the content is usually 0.005 to 0.2 parts by weight, preferably 0.01 to 0.1 parts by weight with respect to 100 parts by weight of the resin component (C component).

  In the present invention, n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate (for example, Ciba Specialty Chemicals, trade name: Irganox 1076), Phenol-based oxidation of tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (for example, Ciba Specialty Chemicals, trade name: Irganox 1010) An inhibitor may be used. The blending ratio of the antioxidant may be appropriately selected and determined. However, if the content is too small, the effect of the antioxidant is small, and conversely, if the content is too large, an increase in the effect commensurate with the increase in the amount of addition is expected. In addition to being unable to do so, mold deposits may easily occur. Therefore, usually, the content is preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the resin component (C component).

  The light diffusing resin composition of the present invention may further contain, for example, a mold release agent, an antistatic agent, a colorant, a fluidity improver, a flame retardant, an anti-aggregation agent and the like as necessary.

  The mixing and kneading of the light diffusing resin composition of the present invention may be performed by a method applied to ordinary thermoplastic resins, such as a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, 2 It can be carried out by an axial screw extruder, a multi-screw extruder or the like. The temperature condition for kneading is usually 260 to 300 ° C.

  The light diffusing resin composition of the present invention can be applied to a general thermoplastic resin molding method. For example, injection molding, injection compression molding, and extrusion molding from a pellet-shaped resin composition are possible from the viewpoint of productivity. Furthermore, it can also be set as the target molded object by vacuum forming, pressure forming, etc. from the extruded sheet-like molded product.

  Examples of the light diffusing member molded from the light diffusing resin composition of the present invention include a light guide plate, a diffusion plate, a reflection plate, a protective film, a retardation film, and a lighting cover, a lighting signboard, and a transmission type for a liquid crystal display device. These screens, various displays, and the like can be mentioned, and among them, it can be suitably used as an optical member for a liquid crystal display device.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. Table 1 shows the raw materials used in Examples, Reference Examples and Comparative Examples. In addition, the manufacturing method of resin used for the Example and the comparative example, and the evaluation method of the resin composition in each Example, a reference example, and a comparative example are as follows.

(1) Production method of alicyclic polyester resin 1,4-cyclohexanedicarboxylic acid was added to a stainless steel reactor equipped with a stirrer, a distilling tube, a heating device, a pressure gauge, a thermometer and a pressure reducing device, and having a capacity of 100 liters. (Trans isomer: cis isomer ratio is 96: 4) 101.5 parts by weight, 1,4-cyclohexanedimethanol (trans isomer: cis isomer ratio is 69:31) 87 parts by weight and tetra-n-butyl titanate 0.005 part by weight of a 6% by weight butanol solution was charged, and the inside of the reactor was replaced with nitrogen gas.
While sealing the inside of the reactor with nitrogen gas, the internal temperature was raised to 150 ° C. in 30 minutes, and further raised from 150 ° C. to 200 ° C. over 1 hour. Next, after carrying out the esterification reaction by holding at a temperature of 200 ° C. for 1 hour, the polycondensation reaction is carried out while gradually raising the pressure in the reactor while increasing the temperature from 200 ° C. to 250 ° C. over 45 minutes. It was. The pressure inside the reactor was maintained at an absolute pressure of 0.1 kPa and a reaction temperature of 250 ° C. and maintained for 4.5 hours to complete the polycondensation reaction. After completion of the polycondensation reaction, the obtained resin was extracted in a strand shape into water, cut and pelletized. The intrinsic viscosity was 0.841 dl / g.

<Method for measuring intrinsic viscosity>
About 0.25 g of a sample was dissolved in about 25 mL of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (weight ratio 1/1) to a concentration of 1.00 g / dL, and then 30 Cool and hold at 0 ° C., and measure the number of seconds of dropping only the sample solution and solvent with a concentration of 1.00 × 10 ⁻² g / dL using a fully automatic solution viscometer (“2CH type DJ504” manufactured by Chuo Rika Co., Ltd.) And calculated by the following formula.
IV = ((1 + 4K _H ηsp) 0.5-1) / (2K _H C)
Here, ηsp = η / η ₀ −1, η is the sample solution drop seconds, η ₀ is the solvent drop time, C is the sample solution concentration (g / dL), and K _H is the Huggins constant. It is. K _H was 0.33, and the dissolution condition of the sample was 110 ° C. for 30 minutes when the sample was a prepolymer.

(2) Viscosity average molecular weight (Mv):
The intrinsic viscosity [η] at 20 ° C. in methylene chloride was measured using an Ubbelohde viscometer, and determined from the following formula.
[Η] = 1.23 × 10 ⁻⁴ × (Mv) ^0.83

(3) Hue (YI) evaluation:
Each of the above measurements was performed on a plate (90 mm × 50 mm × 3 mm) molded at a temperature of 300 ° C. using an injection molding machine (“J50” manufactured by Nippon Steel Works). For the measurement, a spectroscopic color meter (“SE-2000 type” manufactured by Nippon Denshoku Industries Co., Ltd.) was used.

(4) Light resistance evaluation:
The plate molded in (3) was irradiated with UV to evaluate light resistance. The UV irradiation apparatus was a Super Xenon Weather Meter manufactured by Suga Test Instruments Co., Ltd., an irradiation intensity of 156 W / m ² and an irradiation time of 600 hours.

(5) Izod impact strength:
Measurement was performed in accordance with ASTM D-256 using a test piece of 64 mm × 12.4 mm × 3.2 mm molded at 300 ° C. with an injection molding machine (M150 manufactured by Meiki Seisakusho Co., Ltd.). The measurement was performed with a notch.

(6) Total light transmittance and haze:
The total light transmittance and haze of the test piece molded in (3) were measured with a turbidimeter (NDH-2000 type, manufactured by Nippon Denshoku Industries Co., Ltd.).

(7) Diffusion rate:
Using GP-5 GONIOPHOTOMETER made by MURAKAMI COLOR RESEARCH LABORATORY, the measurement conditions are incident light 0 °, tilt angle 0 °, light receiving range 0 ° to 90 °, light beam aperture 2.0, light receiving aperture 3.0. Then, the luminance of the test piece molded in (3) was measured, and the diffusivity (%) was obtained by the following formula.
Diffusivity (%) = {(20 ° luminance + 70 ° luminance) / (5 ° luminance) × 2} × 100

( Reference Example 1, Examples 2 to 5 and Comparative Examples 1 to 6)
After blending each raw material in the ratios shown in Tables 2 and 3, melt-kneaded at a cylinder temperature of 250 ° C. with a single screw extruder with a screw diameter of 40 mm (“VS-40” manufactured by Tanabe Plastics Machinery Co., Ltd.) Pellets were obtained by cutting, and the obtained pellets were dried at 120 ° C. for 5 to 7 hours with a hot-air circulating dryer, and then a molded article for evaluation was molded under the above conditions. And the said evaluation was performed and the result was shown in Table 2 and Table 3.

When the results of Examples and Comparative Examples described in Table 2 and Table 3 below are compared, in Examples 2 to 5, excellent light transmittance ("total light transmittance" in the table) is 63 at the same time. .6% or more), excellent discoloration resistance during melt processing ("Initial YI" in the table is 17 or less), and excellent discoloration resistance during use ( "YI after UV irradiation" in the table) 22 and below, and “YI after UV irradiation” in the table− “initial YI” = ΔYI is 5 or less), whereas in Reference Example 1 and Comparative Examples 1 to 6, the light transmittance As for the resistance to discoloration at the time of melt processing and the resistance to discoloration at the time of use, it is clear that one or more of the characteristic values shown in parentheses is not satisfied, and the intended effect of the present invention has not been achieved.

As a result of intensive studies to solve the above problems, the present inventors have found that a resin composition in which a specific alicyclic polyester resin, a light diffusing agent, and an ultraviolet absorber are blended with an aromatic polycarbonate resin has excellent light diffusibility. In addition, the present inventors have found that the total light transmittance is high and that discoloration during melt processing and use can be suppressed, and the present invention has been completed. That is, the gist of the present invention, Fang aromatic polycarbonate resin (A component) 30 to 99 parts by weight of the alicyclic polyester resin (B component) resin component (C component) containing 1 to 70 parts by weight per 100 parts by weight 0.05 to 10 parts by weight of organic light diffusing fine particles having a weight average diameter of 0.7 to 30 μm, and further 0 UV absorbers having a longest absorption wavelength of 380 nm or less , which are malonic acid esters and / or cyanoacrylates. A light diffusing member formed by molding a light diffusing resin composition containing 0.05 to 5 parts by weight , measured on a plate (90 mm × 50 mm × 3 mm) obtained by injection molding the light diffusing resin composition at 300 ° C. is the value of the initial YI is 17 or less, and, to the plate, the irradiation intensity 156W / ^{m 2,} the irradiation time 600 hours, as measured according to light resistance evaluation for irradiating UV, UV It exists in the light diffusion member, wherein the difference between the value and the initial YI of YI (YI- initial YI after UV irradiation) is 5 or less after the morphism.

Claims (3)

In the light diffusing member including the light diffusing resin composition, the light diffusing resin composition comprises 30 to 99 parts by weight of an aromatic polycarbonate resin (A component) and 1 to 70 parts by weight of an alicyclic polyester resin (B component). parts of the resin component (C component) 100 parts by weight comprising, by weight 0.05 to 20 parts by weight of an organic light diffusing fine particles having an average diameter of 0.7～30Myuemu, further longest absorption wavelength 380nm or less of the ultraviolet absorbing A light diffusing member comprising 0.05 to 5 parts by weight of an agent . 2. The light diffusing member according to claim 1, wherein the ultraviolet absorber having a longest absorption wavelength of 380 nm or less of the light diffusing resin composition is malonic acid esters and / or cyanoacrylates. Light diffusing member . In light diffusing member according to claim 1 or 2, the light diffusing resin composition with respect to further resin component (C component) 100 parts by weight, to include fluorescent dyes 0.00001 parts by weight A light diffusing member characterized .