JP5238277B2 - Light diffusing molded body and image display device - Google Patents

Description

  The present invention relates to a light diffusive molded article and an image display device, and in particular, a light diffusible molded article advantageously used in an image display device such as a backlight type liquid crystal display device, and such a light diffusible molded product. The present invention relates to an image display device using a body.

  A light diffusive molded product is a molded product that diffuses and emits incident light, and it is difficult to irradiate the whole evenly due to the positional relationship with the light source, etc. It is used for. For example, in a backlight-type liquid crystal display device (LCD), the plate-shaped molded body (light diffusing plate) is installed between the light source and the back of the display, and the light from the backlight light source in the immediate vicinity of the liquid crystal is installed. However, the light is emitted uniformly from the display surface so that no light and darkness occurs on the display.

  Conventionally, such a light diffusible molded body is formed by dispersing and containing transparent particles having a diameter of several μm to several tens of μm in a transparent substrate made of polymethyl methacrylate resin or polycarbonate resin. The thing (refer patent document 1), the thing which provided the unevenness | corrugation which diffuses light on the surface of a transparent substrate (refer patent document 2), or these combination are known.

  However, a light diffusive molded article made of such polymethyl methacrylate resin or polycarbonate resin is not always sufficient in terms of heat resistance, light transmittance, dimensional accuracy, chemical resistance, and water absorption rate. Since it is high and hydrolysis occurs, there are problems that optical characteristics are easily changed and chromatic aberration is also present.

  In addition, the light diffusive molded body is required to realize a lighter light diffusible molded body in order to reduce cost and weight. Therefore, in order to reduce the weight, it is necessary to reduce the thickness of the plate-shaped molded body or to reduce the specific gravity of the resin itself. In order to ensure the strength and rigidity of the shaped molded body, there are currently limitations.

  On the other hand, alicyclic polyolefin and cyclic polyolefin are known as thermoplastic resins having excellent optical properties. These are roughly classified into norbornene or dicyclopentadiene ring-opening polymerization hydrogenated products, norbornene or dicyclopentadiene and olefin addition copolymers (see Patent Document 3), and vinylcyclohexane polymers (Patent Document 4). Classification). Among these, the vinylcyclohexane polymer has high heat resistance, low water absorption, low specific gravity, and low birefringence, but is brittle and has light resistance because of having a bulky substituent in the side chain. There are problems that are not enough. Furthermore, cyclic polyolefins other than vinylcyclohexane-based polymers have high heat resistance and low water absorption, but have high specific gravity and insufficient light resistance.

  As thermoplastic resins having a low specific gravity, so-called polyolefins such as polypropylene and polyethylene are known (see Patent Document 5). However, since they are crystalline, they are low in transparency, low in refractive index, and heat resistant. Is not enough. Further, the 4-methylpentene-1 polymer (see Patent Document 6) has a low specific gravity and a high melting point, but has a low refractive index, is crystalline, and does not satisfy optical performance such as birefringence. .

JP 2004-109893 A JP-A-2005-315998 JP 2000-221328 A Japanese Patent Laid-Open No. 63-43910 Japanese Patent Laid-Open No. 7-306319 Japanese Patent Laid-Open No. 2004-101641

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is to provide a light diffusible molded article having high heat resistance, good light resistance, and light weight. Further, another object is to provide an image display device using such a light diffusable molded article.

  And as a result of intensive studies to solve such problems, the present inventors have used a predetermined β-pinene polymer, and thereby intended light-diffusing molded articles and images using the same. The present inventors have found that a display device can be advantageously obtained and have completed the present invention.

That is, the present invention has a specific gravity of 0.85 or more and less than 1.0 state, and are glass transition temperature of 100 ° C. or higher, and a weight average molecular weight of 30,000 to 1,000,000 der Ru β- pinene polymer The gist of the light diffusive molded article is characterized in that the thickness is 0.8 to 10 mm.

  In addition, according to one of the desirable embodiments of the light diffusive molded article according to the present invention, the β-pinene polymer is hydrogenated and ([(hydrogenated olefinic diene)]. The number of heavy bonds] / [number of olefinic double bonds in the polymer before hydrogenation]) × 100 is 95% or more.

  Moreover, according to one of the advantageous aspects of the light diffusable molded article according to the present invention, a predetermined light diffusing agent is blended and contained in such a light diffusible molded article. And according to one of the preferable aspects of such a light diffusable molded object according to this invention, the difference of the refractive index of the said beta-pinene polymer and the refractive index of the said light diffusing agent is 0.005 or more. According to another preferred embodiment, 0.01 to 20 parts by mass of the light diffusing agent is added to 100 parts by mass of the β-pinene polymer.

  Furthermore, according to one of the other preferable aspects of the light-diffusion molded object according to this invention, the light-diffusion means is integrally provided in the light-projection surface.

  In addition, the gist of the present invention is also an image display device including a light source and the light diffusing molded body as described above.

  In such a light diffusible molded article according to the present invention and an image display device using the same, since a predetermined β-pinene polymer is used as a material for forming the light diffusible molded article, such β -Due to the excellent properties of the pinene polymer, the following effects can be obtained.

(1) Since the β-pinene polymer used as the light diffusive molding material is a polymer having a small specific gravity, it is possible to effectively reduce the weight of the target light diffusing molding. It becomes.
(2) Since such β-pinene polymer has high heat resistance and low water absorption, it is effective for the light diffusive molded body to be deformed by the heat of the light source or to be deformed by water adsorption / desorption. This can prevent the change in the image quality of the video.
(3) The light diffusive molded article according to the present invention can be advantageously thinned because the elastic modulus and impact resistance are highly balanced.
(4) The light diffusive molded article according to the present invention has a feature that no harmful gas is generated even if it is discarded and then incinerated.
(5) Since the β-pinene polymer used in the present invention has a low melt viscosity with respect to the molecular weight, it can be molded at a lower temperature, and therefore, thermal degradation of the molded product can be effectively suppressed.
(6) Since the light diffusable molded article according to the present invention has high transparency, it is possible to obtain a clear image.
(7) Since the light diffusable molded article according to the present invention has high light resistance, it has an advantage that the performance is not deteriorated when used for a long time.
(8) Since the β-pinene polymer used in the present invention can be obtained from a raw material derived from a natural product, it is a carbon neutral material and has environmentally friendly characteristics.

However, beta-pinene polymers used as light-diffusing molded material in accordance the present invention, a specific gravity of 0.85 or more and less than 1.0, glass transition temperature Ri der 100 ° C. or higher, and the weight average molecular weight of from 30,000 to 1,000,000 der Ru β- pinene polymer. Here, the β-pinene polymer in the present specification and claims refers to a polymer (polymer) having a β-pinene content of 50% by mass or more. In the light diffusion molded article according to the present invention, a β-pinene polymer having a β-pinene content of 60% by mass or more is advantageously used, and more preferably, the β-pinene content is 70% by mass or more. Β-pinene polymer is used.

  As the β-pinene used as a raw material for producing such β-pinene polymer, any conventionally known one can be used. For example, what is collected from plants such as pine and citrus can be used directly after purification, as well as terpenes such as α-pinene collected from plants and petroleum-derived compounds. Β-pinene and the like produced according to a more known technique (for example, the technique disclosed in US Pat. No. 3,278,623) can also be used. The β-pinene polymer obtained using such plant-derived β-pinene is a carbon neutral material, and in this respect, the light diffusive molded article according to the present invention is capable of forming a recycling society. It can contribute to the prevention of global warming.

  Further, the β-pinene polymer used in the present invention may be a homopolymer of the above-described β-pinene, or at least one kind of other copolymerizable monomers with β-pinene. There is no problem even if it is a copolymer of. Examples of monomers copolymerizable with β-pinene include cationic polymerizable monomers, radical polymerizable monomers, coordination polymerizable monomers, and plant-derived terpenes.

  In the present invention, the cationically polymerizable monomer, radically polymerizable monomer, and coordination polymerizable monomer that are used when producing the β-pinene polymer are generally used conventionally. It is possible to use what is. Plant-derived terpenes can also be used as the polymerizable monomer in any of the cationic polymerization method, radical polymerization method and coordination polymerization method. Specifically, as the cationic polymerizable monomer, isobutylene, isoprene, butadiene, styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, pt-butoxystyrene, indene, alkyl vinyl ether, norbornene Further, as the radical polymerizable monomer, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate (Meth) acrylates such as 2-hydroxypropyl (meth) acrylate and glycidyl (meth) acrylate; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide Chromatography; vinyl acetate, vinyl pivalate, vinyl esters such as vinyl benzoate, vinyl chloride, vinylidene chloride, maleic anhydride, maleic acid, fumaric acid, fumaric acid esters, may be mentioned maleimide. Examples of coordination polymerizable monomers include ethylene, propylene, 1-hexene, cyclopentene, norbornene, and plant-derived terpenes include myrcene, alloocimene, omecine, α-pinene. , Dipentene, limonene, α-ferrandrene, α-terpinene, γ-terpinene, 2-carene, 3-carene and the like. Among these, one or more types are appropriately selected and used according to the amount of β-pinene used. Since the β-pinene polymer is advantageously obtained by the cationic polymerization method, among the polymerizable monomers as described above, the cationic polymerizable monomer is particularly advantageously used.

  In the case where the copolymerizable monomer is copolymerized with β-pinene, the amount of copolymerization is preferably 0.001 to 50% by mass in the polymer, and more preferably 0.01 to 20% by mass. Preferably, 0.05-10 mass% is the most preferable. If the amount of copolymerization is too large, problems such as increased water absorption and reduced heat resistance are undesirable.

  On the other hand, a small amount of bifunctional or higher crosslinkable monomer (hereinafter referred to as a crosslinkable monomer) is copolymerized together with or in place of the above copolymerizable monomer. I can do it. Such a crosslinkable monomer is generally used as a branching agent or a crosslinking agent in the production of a polymer, but has a so-called long chain branching structure by reducing the amount used. A β-pinene polymer having a molecular weight that does not cause an insoluble part in an organic solvent is advantageously obtained. Specific examples of the crosslinkable monomer that can be used in the present invention include m-diisopropenylbenzene, p-diisopropenylbenzene, m-divinylbenzene, p-divinylbenzene, and 1,4-cyclohexanedimethanoldi. Bifunctional vinyl compounds such as vinyl ether and ethylene glycol divinyl ether can be mentioned, and among them, m-diisopropenylbenzene is preferably used from the viewpoints of economy and reactivity.

  When such a crosslinkable monomer is copolymerized with β-pinene (and a monomer copolymerizable with β-pinene), the copolymerization amount is 0.001 to 7% by mass in the polymer. Among them, 0.01 to 5% by mass is more preferable, and 0.05 to 4% by mass is most preferable. If the amount of copolymerization is too large, the resulting β-pinene polymer becomes gel and loses thermoplasticity, which is not preferable.

  By the way, the polymerization method of the β-pinene polymer used in the present invention is not particularly limited, and a known polymerization method suitable for the polymerizable monomer can be appropriately selected. For example, any one of an anionic polymerization method, a cationic polymerization method, a radical polymerization method and a coordination polymerization method can be selected and used, but in general, a cationic polymerization method is adopted.

In the case of obtaining the β-pinene polymer used in the present invention according to the cationic polymerization method, a known cationic polymerization catalyst is appropriately used as the polymerization catalyst. Specifically, BF ₃ , BF ₃ OEt ₂ , BBr ₃ , BBr ₃ OEt ₂ , AlCl ₃ , AlBr ₃ , AlI ₃ , TiCl ₄ , TiBr ₄ , TiI ₄ , FeCl ₃ , FeCl ₂ , SnCl ₂ , SnCl ₄ , WCl ₆ , MoCl ₅ , SbCl ₅ , TeCl _2, etc., Group 3-16 group metal halogen compounds; HF, HCl, HBr, etc. hydrogen acids; H ₂ SO ₄ , H ₃ BO ₃ , HClO ₄ , oxo acids such as CH ₃ COOH, CH ₂ ClCOOH, CHCl ₂ COOH, CCl ₃ COOH, CF ₃ COOH, p-toluenesulfonic acid, CF ₃ SO ₃ H, H ₃ PO ₄ , P ₂ O ₅ , and these Polymer compounds such as ion exchange resins having a group; heteropolyacids such as phosphomolybdic acid and phosphotungstic acid; SiO ₂ , Al ₂ O ₃ , SiO ₂ -Al ₂ O ₃ , MgO-SiO ₂ , B ₂ O ₃ —Al ₂ O ₃ , WO ₃ —Al ₂ O ₃ , Zr ₂ O ₃ —SiO ₂ , sulfated zirconia, tungstate zirconia, zeolite exchanged with H ⁺ or rare earth elements, activated clay, acidic Examples thereof include solid acids such as solid phosphoric acid in which clay, γ-Al ₂ O ₃ , and P ₂ O ₅ are supported on diatomaceous earth.

These cationic polymerization catalysts may be used in combination, and other compounds may be added to the polymerization system. Such other compounds are compounds that can improve the activity of the catalyst, for example, by adding them. Examples of compounds that improve the activity of metal halide compounds as acidic compounds include MeLi, EtLi, BuLi, Et ₂ Mg, EtMgBr, Et ₃ Al, Et ₂ AlCl, EtAlCl ₂ , Et ₃ Al ₂ Cl ₃ , (I-Bu) ₃ Al, Et ₂ Al (OEt), metal alkyl compounds such as Me ₄ Sn, Et ₄ Sn, Bu ₄ Sn, Bu ₃ SnCl; 2-methoxy-2-phenylpropane, t-butanol, 1 , 4-bis (2-methoxy-2-propyl) benzene, 2-phenyl-2-propanol, and the like are exemplified as compounds used as a polymerization initiator in living cationic polymerization.

  Further, as a polymerization method of the β-pinene polymer used in the present invention, a solution polymerization method using a solvent may be used. The solvent that can be used varies depending on the polymerization method employed, and thus it is difficult to define it uniquely. For example, aromatic hydrocarbon solvents such as benzene, toluene, xylene, etc .; pentane, hexane, heptane, Aliphatic hydrocarbon solvents such as octane, cyclopentane, cyclohexane, methylcyclohexane, decalin; halogenated hydrocarbon solvents such as methyl chloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethylene; esters, Examples thereof include oxygen-containing solvents such as ether. In view of reactivity, it is preferable to use an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a halogenated hydrocarbon solvent, or the like. These solvents may be used alone or in combination of two or more.

  Although the usage-amount of such a solvent is not specifically limited, About 100-10000 mass parts normally with respect to 100 mass parts of monomers, such as (beta) -pinene, Preferably it is 150-5000 mass parts, More preferably, it is 200-3000. Part by mass. When the amount of the solvent is small, uniform mixing of the polymerization catalyst becomes difficult, so that the reaction becomes non-uniform, and a uniform polymer cannot be obtained, or the control of the reaction becomes difficult. On the other hand, when the amount of solvent is large, there is a problem that productivity is lowered.

  And when performing a polymerization reaction, -80 degreeC-100 degreeC is preferable normally, especially, -40 degreeC-80 degreeC is more preferable, and -20 degreeC-80 degreeC is the most preferable. If this reaction temperature is too low, the progress of the reaction is slow, and if it is too high, it becomes difficult to control the reaction and it is difficult to obtain reproducibility.

  Moreover, the reaction pressure for performing the polymerization reaction is not particularly limited, but is preferably 0.5 to 50 atm, and more preferably 0.7 to 10 atm. Usually, the polymerization reaction is performed at around 1 atm.

  Furthermore, the reaction time for conducting the polymerization reaction is not particularly limited, and the reaction time may be appropriately determined so that a β-pinene polymer is obtained in good yield according to conditions such as reaction temperature and reaction pressure. Good. Usually, it is about 0.01 to 24 hours, preferably 0.2 to 10 hours.

  By the way, the β-pinene polymer produced by the polymerization reaction can be obtained by, for example, reprecipitation, solvent removal under heating, solvent removal under reduced pressure, solvent removal with steam (steam stripping), etc. It can be separated and obtained from the reaction mixture by a normal operation in isolation from the solution.

The β-pinene polymer used in the present invention preferably has hydrogenated olefinic double bonds from the viewpoints of light resistance, impact resistance, heat resistance and the like. In general, the hydrogenation rate is preferably 90% or more, more preferably 95% or more, and most preferably 99% or more. In the present invention, the β-pinene polymer is hydrogenated and shows the hydrogenation rate ([number of hydrogenated olefinic double bonds] / [before hydrogenation]). The number of olefinic double bonds in the polymer]]) × 100 is desirably 95% or more. The hydrogenation rate of the unsaturated double bond (carbon-carbon double bond) in the hydrogenated polymer is determined by iodine titration method, infrared spectroscopic spectrum measurement, nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum). It can be calculated using an analysis means such as measurement.

  Here, the method for hydrogenating the β-pinene polymer used in the present invention is not particularly limited, and a known method can be used. For example, homogeneous catalysts such as Wilkinson complex, cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, diatomaceous earth, magnesia, alumina, silica, alumina-magnesia, silica-magnesia, silica-alumina, synthetic zeolite, etc. A known method using a heterogeneous catalyst or the like in which a catalyst metal such as nickel, palladium, or platinum is supported on a support can be used.

  As a solvent that can be used for hydrogenation, any organic solvent that dissolves the polymer and is inert to the hydrogenation catalyst can be used. Specifically, aromatic hydrocarbon solvents such as benzene, toluene, xylene; aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclopentane, cyclohexane, methylcyclohexane, decalin; methyl chloride, methylene chloride Halogenated hydrocarbon solvents such as 1,2-dichloroethane, 1,1,2-trichloroethylene; oxygen-containing solvents such as esters and ethers. In view of reactivity, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents and the like are preferable. These solvents may be used alone or in combination of two or more.

Furthermore, the reaction temperature of the hydrogenation reaction depends on the hydrogenation catalyst used and the hydrogen pressure, but is generally preferably about 20 ° C to 250 ° C, more preferably 25 ° C to 150 ° C, and even more preferably 40 ° C to 100 ° C. Is most preferred. If the reaction temperature is too low, the reaction will not proceed smoothly, and if the reaction temperature is too high, side reactions and molecular weight will tend to occur. The hydrogen pressure is preferably about normal pressure to about 200 kgf / cm ² , more preferably 5 to 100 kgf / cm ² . If the hydrogen pressure is too low, the reaction does not proceed smoothly, and if the hydrogen pressure is too high, there are restrictions on the apparatus.

  In addition, the density | concentration of (beta) -pinene polymer in such a hydrogenation reaction system is about 2 mass%-40 mass% normally, Preferably it is 3 mass%-30 mass%, More preferably, it is 5 mass%-20 % By mass. If the concentration of β-pinene polymer is low, productivity is likely to decrease, which is not preferable. Moreover, when the density | concentration of (beta) -pinene polymer is too high, the hydrogenated polymer may precipitate or the viscosity of a reaction mixture may become high and it may become difficult to perform stirring smoothly, and is unpreferable.

  The reaction time of the hydrogenation reaction depends on the hydrogenation catalyst used, the hydrogen pressure, and the reaction temperature, but is usually about 0.1 to 50 hours, preferably 0.2 to 20 hours, more preferably 0.5 hours to 10 hours will be employed.

  Furthermore, the β-pinene polymer after the hydrogenation reaction may be polymerized by, for example, reprecipitation, solvent removal under heating, solvent removal under reduced pressure, or solvent removal with steam (steam stripping). The product is separated and obtained from the reaction mixture by a normal operation for isolation from the solution.

By the way, the molecular weight of the β-pinene polymer used in the present invention is 30,000 to 100 in terms of weight average molecular weight from the viewpoints of the viscosity and melt viscosity of the polymerization solution, the moldability, the strength of the light diffusible molded body, and the heat resistance. Ri Ah in ten thousand, 40,000 to 500,000 are favorable preferred, in particular from 60,000 to 250,000 is preferred, from 90,000 to 200,000 being most preferred. The weight average molecular weight of the polymer can be calculated using a known analysis method such as gel permeation chromatography (GPC) obtained in terms of polystyrene or static light scattering measurement (SLS).

  In addition, the glass transition temperature (Tg) of the β-pinene polymer used in the present invention is preferably higher from the usage environment of the light diffusible molded body, and in order to avoid the adverse effects due to the heat of the light source, it is 100 ° C. or higher. Among these, it is more preferable that the temperature is 110 ° C. or higher. The upper limit of the glass transition temperature is not particularly defined, but is preferably about 200 ° C. This is because in an amorphous polymer such as the β-pinene polymer used in the present invention, if the glass transition temperature is too high, the entanglement of the polymer is reduced, and the molded product may become brittle.

  Further, the total light transmittance of the β-pinene polymer used in the present invention is preferably high, and in a state where no light diffusing agent is blended, generally in a flat test piece having a thickness of 3.2 mm. It is preferably 80% or more, more preferably 85% or more, and most preferably 90% or more.

  Furthermore, the β-pinene polymer used in the present invention preferably has a lower water absorption rate from the viewpoint of dimensional stability. The water absorption of the β-pinene polymer is preferably 0.2% or less as a saturated water absorption when placed in an atmosphere of 60 ° C. and 90% RH (relative humidity), more preferably 0.1% or less. In particular, 0.05% or less is most preferable. A β-pinene polymer giving such a water absorption rate is advantageously selected.

  Such a β-pinene polymer used in the present invention is characterized by a low specific gravity. Since the specific gravity is small, a lighter light diffusive molded article can be obtained. Accordingly, the specific gravity of the β-pinene polymer used in the present invention needs to be 0.85 or more and less than 1.0, and more preferably 0.85 to 0.98. This is because it is difficult to obtain a polymer having a specific gravity smaller than 0.85, and when the specific gravity is 1.0 or more, the object of weight reduction cannot be sufficiently achieved.

  In addition, the β-pinene polymer for molding the light diffusive molded article according to the present invention may contain various known compounding agents as needed, as long as the purpose of the present invention is not impaired. Alternatively, two or more types may be combined and mixed.

  Specific examples of such various compounding agents are not particularly limited as long as they are usually used in the resin industry. For example, antioxidants, ultraviolet absorbers, light stabilizers, near infrared absorption And compounding agents such as a colorant such as a colorant, a dye and a pigment, a lubricant, a plasticizer (softening agent), an antistatic agent, a fluorescent brightening agent, and a filler.

  Among them, examples of antioxidants include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, etc. Among them, phenolic antioxidants are preferable, and alkyl-substituted phenolic oxidations. Inhibitors are particularly preferred.

  As the phenolic antioxidant used here, specifically, conventionally known ones can be used. For example, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methyl Benzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate, etc. Acrylate compounds such as those described in JP-A-179953 and JP-A-1-168463; octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2′-methylene -Bis (4-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5- Limethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxy) Phenylpropionate) methane [i.e. pentaerythrimethyl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)], triethylene glycol bis (3- (3-t-butyl- Alkyl-substituted phenolic compounds such as 4-hydroxy-5-methylphenyl) propionate); 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5 -Triazine, 4-bisoctylthio-1,3,5-triazine, 2-octylthio-4,6-bis- (3,5-di-t-butyl-4-oxyani Roh) triazine group-containing phenol compounds such as 1,3,5-triazine.

The phosphorus antioxidant is not particularly limited as long as it is usually used in the general resin industry. For example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris ( Nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl)- Monophosphite compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tri Decylphosphite), 4,4′-isopropylidene-bis (phenyl-di-alkyl (C ₁₂ -C ₁₅ ) phosphite) And diphosphite-based compounds. Among these, monophosphite compounds are preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like are particularly preferable.

  Furthermore, examples of the sulfur antioxidant include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3. -Thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thiopropionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5 ] Undecane etc. can be mentioned.

  And these antioxidant can be used individually or in combination of 2 or more types, respectively. The blending amount of such an antioxidant is appropriately determined within a range where the object of the present invention is not impaired, but is usually 0.001 with respect to 100 parts by mass of the β-pinene polymer. It is about -5 mass parts, Preferably it is the range of 0.01-1 mass part.

  Examples of the ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole, 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro- 2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) ) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-t-amyl-2-) Benzotriazole ultraviolet absorbers such as hydroxyphenyl) -2H-benzotriazole; 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxy Zoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- (2H- Benzotriazol-2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole Benzoate ultraviolet absorbers such as 2- (2-hydroxy-4-octylphenyl) -2H-benzotriazole; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone -5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxybenzophenone, 4 Benzophenone series such as dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone UV absorbers; acrylate UV absorbers such as ethyl-2-cyano-3,3-diphenyl acrylate, 2′-ethylhexyl-2-cyano-3,3-diphenyl acrylate; [2,2′-thiobis (4- t-octylphenolate)]-2-ethylhexylamine nickel and other metal complex ultraviolet absorbers and the like can be used.

  Furthermore, examples of the light stabilizer include 2,2,6,6-tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, and bis (1,2 , 2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, 4- (3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionyloxy) -1- (2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -2,2, Examples thereof include hindered amine light stabilizers such as 6,6-tetramethylpiperidine.

  In addition, as the near-infrared absorber, for example, cyanine-based near-infrared absorber; pyrylium-based near-infrared absorber; squarylium-based near-infrared absorber; croconium-based near-infrared absorber; Infrared absorbers; dithiol metal complex-based near infrared absorbers; naphthoquinone near infrared absorbers; anthraquinone near infrared absorbers; indophenol near infrared absorbers; As commercially available near infrared absorbers, SIR-103, SIR-114, SIR-128, SIR-130, SIR-132, SIR-152, SIR-159, SIR-162 (above, Mitsui Toatsu Dye Co., Ltd.) Company-made), Kayasorb IR-750, Kayasorb IRG-002, Kayasorb IRG-003, Kayasorb IR-820B, Kayasorb IRG-022, Kayasorb IRG-023, Kayasorb CY-2, Kayasorb CY-2 , Manufactured by Nippon Kayaku Co., Ltd.).

  The dye is not particularly limited as long as it is uniformly dispersed / dissolved in the β-pinene polymer to be used, but has excellent compatibility with the β-pinene polymer used in the present invention. Therefore, oil-soluble dyes (various CI solvent dyes) are widely used. Specific examples of the oil-soluble dye include “Color Index” published in The Society of Dyers and Colorists, Vol. 3. Various C.I. I. Solvent dyes may be mentioned.

  Further, among the pigments, organic pigments include, for example, diarylide pigments such as Pigment Red 38; azo lake pigments such as Pigment Red 48: 2, Pigment Red 53, Pigment Red 57: 1; Pigment Red 144, Pigment Red 166, Pigment Red 220, Pigment Red 221, Pigment Red 248, and other condensed azo pigments; Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208, and other benzimidazolone pigments; Pigment Red 122 Quinacridone pigments such as Pigment Red 149, Pigment Red 178, and Pigment Red 179; and anthraquinone pigments such as Pigment Red 177. Examples of inorganic pigments include titanium oxide, carbon black, red pepper, chrome red, molybdenum red, resurge, and iron oxide.

  In addition, when coloring is required for the light diffusable molded article used in the present invention, any of the dyes and pigments described above can be used within the scope of the present invention, and is particularly limited. However, in the case of a light diffusible molded article in which micro optical properties are a problem, coloring with a dye is preferable. In addition, the ultraviolet absorber may show a yellow to red color visually, and the near infrared absorber may show a black color visually, so there is no need to use these and dyes strictly, Moreover, there is no problem even if they are used in combination.

  As the lubricant, organic compounds such as aliphatic alcohol esters, polyhydric alcohol esters or partial esters, inorganic fine particles, and the like can be used. Here, examples of the organic compound include glycerol monostearate, glycerol monolaurate, glycerol distearate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and the like.

  Further, as other lubricants, generally inorganic fine particles can be used. Here, the inorganic fine particles include oxides, sulfides, hydroxides, nitrides, halides, carbonates, sulfates, acetic acids of the elements of Groups 1, 2, 4, and 6-14 of the periodic table. Examples thereof include fine particles of salts, phosphates, phosphites, organic carboxylates, silicates, titanates, borates and their hydrates, composite compounds centered on them, natural compounds, and the like.

  Examples of the plasticizer include tricresyl phosphate, trixylenyl phosphate, triphenyl phosphate, triethylphenyl phosphate, diphenyl cresyl phosphate, monophenyl dicresyl phosphate, diphenyl monoxylenyl phosphate. Phosphate triester plasticizers such as phosphate, monophenyldixylenyl phosphate, tributyl phosphate, triethyl phosphate; dimethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-phthalate Phthalate plasticizers such as 2-ethylhexyl, diisononyl phthalate, octyldecyl phthalate, and butylbenzyl phthalate; fatty acid monobasic acids such as butyl oleate and glycerol monooleate Plasticizers; dihydric alcohol ester plasticizers; oxyester plasticizers and the like can be used, but among these, phosphate triester plasticizers are preferable, tricresyl phosphate, trixylenitrixylenyl Phosphate is particularly preferred.

Furthermore, as specific examples of other plasticizers, squalane (C ₃₀ H ₆₂ , Mw = 422.8), liquid paraffin (white oil, ISO VG10, ISO VG15, ISO VG32, ISO VG32 as defined in JIS-K-2231) VG68, ISO VG100, ISO VG8 and ISO VG21), polyisobutene, hydrogenated polybutadiene, hydrogenated polyisoprene, and the like. Among these, squalane, liquid paraffin, and polyisobutene are preferably used.

  Furthermore, examples of the antistatic agent include long-chain alkyl alcohols such as stearyl alcohol and behenyl alcohol, fatty acid esters of polyhydric alcohols such as glycerin monostearate and pentaerythritol monostearate, and stearyl alcohol and behenyl alcohol. Particularly preferred.

  These compounding agents can be used alone or in admixture of two or more, and the mixing ratio is appropriately selected within a range not impairing the object of the present invention. The amount of the compounding agent described above is also appropriately selected within a range that does not impair the object of the present invention. However, for each compounding agent, the amount is usually 0. It is about 001-5 mass parts, Preferably it is the range of 0.01-1 mass part.

  The β-pinene polymer for forming the light diffusive molded article according to the present invention is blended with other polymer components as necessary within a range not impairing the object of the present invention. You can also Examples of the other polymer include rubbery polymers, specifically, diene rubbers such as natural rubber, polybutadiene rubber, polyisoprene rubber, acrylonitrile / butadiene copolymer rubber; styrene / butadiene copolymer. Rubber, styrene / isoprene copolymer rubber, styrene / butadiene / isoprene terpolymer rubber; hydrogenated diene rubber; ethylene / α-olefin copolymer such as ethylene / propylene copolymer, propylene / other Saturated polyolefin rubbers such as α-olefin copolymers; α-olefins such as ethylene / propylene / diene copolymers, α-olefin / diene copolymers, isobutylene / isoprene copolymers, and isobutylene / diene copolymers・ Diene polymer rubber; urethane rubber, silicone rubber, polyester Special rubbers such as tellurium rubber, acrylic rubber, propylene oxide rubber and ethylene / acrylic rubber; thermoplastic elastomers such as styrene / butadiene / styrene block copolymer rubber and styrene / isoprene / styrene block copolymer rubber; heat of hydrogenation Mention may be made of plastic elastomers; urethane thermoplastic elastomers; polyamide thermoplastic elastomers; 1,2-polybutadiene thermoplastic elastomers. The blending amount is appropriately selected within a range not impairing the object of the present invention, but is usually about 3 to 30 parts by mass, preferably 5 with respect to 100 parts by mass of the β-pinene polymer. It is the range of -20 mass parts.

  Here, in the present invention, in order to advantageously obtain the desired light diffusive molded article, the above-described β-pinene polymer is further blended with a conventional light diffusing agent. And the molded object of predetermined shapes, such as plate shape and block shape, will be shape | molded using the obtained light diffusable composition.

  Regarding the light diffusing agent used in the present invention, the difference between the refractive index: nD (B1) and the refractive index of the β-pinene polymer: nD (A): ΔnD (= | nD (B1) ) -ND (A) |) is usually 0.005 or more, preferably 0.01 or more. When this refractive index difference: ΔnD exceeds 0.3, the total light transmittance decreases, and when it is less than 0.005, the diffusivity tends to decrease. The light diffusing agent used in the present invention is not particularly limited as long as the light diffusing agent satisfies the conditions of the refractive index and is transparent, but from the viewpoint of obtaining a more excellent light diffusing effect, Those are preferably used.

Examples of such fine particle light diffusing agents include those made of various known inorganic fine particles or organic fine particles. Among them, examples of the inorganic fine particles include silica particles, alumina particles, silica alumina particles, talc, barium carbonate particles, and metal fine particles. In addition, a thin film made of metal oxide such as silicon oxide, zinc oxide, titanium oxide or zirconium oxide, or metal fluoride such as MgF ₂ is formed on the surface of the core fine particles such as glass fine particles, metal fine particles, and synthetic resin fine particles. The formed fine particles can also be used. Furthermore, examples of the organic fine particles include silicone resin particles, acrylic resin particles, nylon resin particles, urethane resin particles, styrene resin particles, polyethylene resin particles, and polyester resin particles. These fine particle light diffusing agents can be substituted by the above-mentioned compounding agents as long as the above-described refractive index difference is satisfied.

  The particle diameter of these fine particles is not particularly limited, but the average particle diameter is usually about 0.5 to 30 μm, preferably 1 to 20 μm, more preferably 1 to 15 μm. When the average particle size is smaller than 0.5 μm, the light diffusibility is increased, but the light transmittance is decreased, and when it is larger than 30 μm, the light transmittance is increased, but the light diffusibility is decreased, Brightness unevenness is likely to occur.

  Furthermore, the more fine particles of the light diffusing agent used in the present invention are, the more preferable it is. When spherical fine particles are used as the light diffusing agent, such spherical fine particles act as a kind of lens and can have a more effective light diffusion effect. Here, the term “spherical” means that the minor axis / major axis of the fine particles are preferably 0.6 or more, more preferably 0.8 or more, and particularly preferably 0.9 or more, and have no corners. The short diameter means the smallest diameter of one fine particle, and the long diameter means the largest diameter of the same fine particle. The ratio of spherical fine particles in the fine particles used here is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. Moreover, what is necessary is just to measure based on the image | video of a micrograph about the short diameter, a long diameter, an average particle diameter, and the presence or absence of an angle | corner. If there are many non-spherical ones, it becomes difficult to obtain a uniform light-diffusible molded article having non-uniform dispersion during molding or having orientation. Note that the light diffusing agent used in the present invention does not need to be one kind, and it is possible to adjust light transmittance and light diffusibility by using a plurality of kinds together.

  In the present invention, the light diffusion state can be changed by controlling the refractive index distribution, size, amount of dispersion, etc. of the light diffusing agent to be dispersed, thus effectively reducing the backscattering of light. And has a merit that a light diffusable molded article having a high total light transmittance can be obtained.

  Such a light diffusing agent is generally 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, particularly preferably 0 to 100 parts by mass of the β-pinene polymer. .Light such as a light diffusing plate with a good balance of properties such as light transmittance, diffusivity, strength, rigidity, thermal deformation temperature and hardness by being used at a ratio in the range of 1 to 10 parts by mass A diffusible molded article can be advantageously obtained.

  Moreover, as a mixing method of the light diffusing agent, a known method can be applied. For example, the components may be mixed (blended), and stirred and mixed under heating. When mixing, it is important to select a temperature at which each component does not deteriorate. Usually, it will be made to mix at the glass transition temperature of the β-pinene polymer to be blended or higher and 300 ° C. or lower.

  In addition, as a shaping | molding method of the light diffusable molded object according to this invention, well-known methods, such as an injection molding method, a hot press molding method, an extrusion molding method, a cutting method, are employ | adopted suitably. Among these, from the viewpoint of productivity, an injection molding method, a hot press molding method, and an extrusion molding method are preferably used.

  In addition, the light diffusing molded body according to the present invention may have a structure in which a mat pattern or a lens function is provided on at least one surface. By integrally providing a light diffusing means such as a structure having a mat pattern or a lens function on the light emitting surface, a light diffusing molded article can be obtained without blending the above-mentioned light diffusing agent. Is possible. In addition, the formation of the lens function having such a mat pattern, a linear or dotted concavo-convex structure may be performed by a casting molding method, an injection molding method, a hot press molding method, an extrusion molding method, a cutting method, or an active energy ray curing. It can be easily produced by a commonly used method such as a method using a mold resin. And, when these mat patterns and lens functions are integrally formed, the light diffusion performance is improved, thereby reducing the amount of such light diffusion agent added when the light diffusion agent is blended. Can be expected.

  Furthermore, the thickness of the light diffusable molded article according to the present invention needs to be 0.8 to 10 mm, and preferably 1 to 5 mm. The thickness of the light diffusible molded product can be made lighter and lighter, and can be reduced in weight. However, if the thickness is less than 0.8 mm, the mechanical strength of the light diffusable molded product is reduced. However, when the thickness exceeds 10 mm, manufacturing may be difficult.

  Then, the light diffusive molded article according to the present invention obtained as described above is used as a light diffusing plate as shown in, for example, Japanese Patent Application Laid-Open No. 2004-109893, Japanese Patent Application Laid-Open No. 2004-354892, etc. It is applied in a structure where light is transmitted in the thickness direction. Moreover, in an illuminating device including such a light diffusing plate, an image display device can be obtained by disposing a transmissive display element on the illuminating side.

  A typical example of such a transmissive display element is a liquid crystal panel. Here, the image display device means a display module in which an illumination device and a display element are combined, and a device having at least an image display function such as a television or a personal computer monitor using the display module. Yes.

  Hereinafter, some examples of the present invention will be shown and the present invention will be more specifically clarified, but the present invention is not limited by the description of such examples. It goes without saying. In addition to the following examples, the present invention can be subjected to various changes, corrections, improvements and the like based on the knowledge of those skilled in the art without departing from the spirit of the present invention. Should be understood.

  First, a β-pinene polymer hydrogenated product was synthesized as follows as a light diffusive molding material according to the present invention.

  About the fully dried glass flask with a cock, after the inside was sufficiently substituted with nitrogen, dehydrated N-hexane: 184 parts by mass, dehydrated methylene chloride: 210 parts by mass, and dehydrated diethyl ether : 0.5 part by mass was added and cooled to -78 ° C. While stirring the mixture at -78 ° C, hexane solution of ethylaluminum dichloride (concentration: 1.0 mol / L): 7.2 parts by mass was further added. Next, in a state where the inside of the flask was kept at −78 ° C., when 3.0 parts by mass of a hexane solution of p-dicumulyl chloride (concentration: 0.1 mol / L) was added, the color changed to red amber. Thereafter, 60 parts by mass of β-pinene that was immediately purified by distillation was added to the flask over 1 hour. The solution gradually became dark blue and the viscosity of the solution increased. After the addition of β-pinene, 30 parts by mass of methanol was added to terminate the reaction. In the flask, an aqueous solution obtained by adding 5 parts by mass of citric acid to 100 parts by mass of distilled water is added and stirred for 5 minutes. Then, the aqueous layer is extracted, and the aqueous layer becomes neutral by adding distilled water. Until the aluminum compound was removed. The obtained organic layer was reprecipitated in a mixed solvent of methanol / acetone (50/50 vol%): 5000 parts by mass and then sufficiently dried to obtain 60 parts by mass of β-pinene polymer (A1). . The obtained β-pinene polymer (A1) had a weight average molecular weight of 116,000, a number average molecular weight of 51,000, and a glass transition temperature of 95 ° C.

By adding 70 parts by mass of cyclohexane and 30 parts by mass of the β-pinene polymer (A1) obtained as described above to a pressure vessel equipped with a stirrer substituted with nitrogen, and stirring the mixture, a β-pinene polymer ( A1) was completely dissolved. Next, 5% palladium-supported alumina (manufactured by NE ChemCat) as a hydrogenation catalyst: 30 parts by mass was added and sufficiently dispersed by stirring, and then the inside of the pressure vessel was sufficiently replaced with hydrogen. While stirring at 1000 rpm, the mixture was reacted at 100 ° C. and hydrogen pressure of 40 kgf / cm ² for 6 hours, and then returned to normal pressure. The reaction solution was diluted by adding 200 parts by mass of cyclohexane, filtered through a 0.5 μm Teflon (registered trademark) filter to separate and remove the catalyst, and then a mixed solvent of methanol / acetone (50/50 vol%): 5000 After re-precipitation in parts by mass, it was sufficiently dried to obtain 29 parts by mass of β-pinene polymer hydrogenated product (H1). When the hydrogenation rate of the obtained β-pinene polymer hydrogenated product (H1) was determined from ¹ H-NMR, it was 99.9%, the weight average molecular weight was 112,000, and the number average molecular weight was 50,800. The glass transition temperature was 130 ° C., the specific gravity was 0.930, and the refractive index was 1.505.

  In addition, about the material obtained at each above-mentioned process, and the material manufactured at the following process, the physical-property measurement was performed as follows.

-Molecular weight-
The number average molecular weight and the weight average molecular weight are both determined in terms of polystyrene based on measurement by gel permeation chromatography (GPC). Here, HLC-8020 (product number) manufactured by Tosoh Co., Ltd. is used as the GPC device, and TSKgel / GMH-M manufactured by Tosoh Co., Ltd. and one G2000H are connected in series as the column. Using.

-Hydrogenation rate-
^{From the 1} H-NMR spectrum, the hydrogenation rate {([number of hydrogenated olefinic double bonds] / [hydrogen] is determined by the reduction rate (%) of olefinic double bond protons (4 to 6 ppm) of the raw material resin. The number of olefinic double bonds in the polymer before addition]) × 100 (%)} was determined.

-Glass transition temperature (Tg)-
It measured by the differential scanning calorimetry (DSC) using the sample which fully dried and removed the solvent. First, a sample is heated from 25 ° C. to 200 ° C. at a rate of temperature increase of 10 ° C./min under a stream of nitrogen of 100 ml / min to obtain a DSC curve. Next, using the obtained DSC curve, as shown in FIG. 1, a parallel line E passing through the intersection of the center tangent B and the base line C before the transition and parallel to the temperature axis, and the center tangent B A parallel line F passing through the intersection of the base line D after the transition and parallel to the temperature axis is drawn. In this specification, the temperature A at the intersection of the parallel line G that bisects the two parallel lines E and F and the DSC curve is defined as the glass transition temperature (Tg). In addition, here, DSC30 (product number) manufactured by METTLER TOLEDO Co., Ltd. was used as a measuring device.

-Total light transmittance and Haze value-
About the obtained light diffusable molded object, it measured based on JIS-K-7361-1 using HR-100 (product number) by Murakami Color Research Laboratory.

-Water absorption rate-
A press-molded plate having a length of 140 mm, a width of 60 mm, and a thickness of 0.8 mm was used and placed in an atmosphere of 60 ° C. and 90% RH for 10 days, and the ratio of the weight increased from the initial weight was determined. The water absorption rate. The arithmetic expression is as follows.
Water absorption (%) = weight increase x 100 / initial weight

-Refractive index (nD)-
It measured at 25 degreeC based on JIS-K-7142 using RX-2000 (product number) made from Atago Co., Ltd ..

-Specific gravity-
It measured according to A method of JIS-K-7112: 1999. Judgment criteria are as follows.
○: Specific gravity ≦ 1.0
Δ: 1.0 <specific gravity ≦ 1.1
×: 1.1 <specific gravity

-Moisture resistance-
A durability test for 1000 hours was performed under the conditions of 80 ° C. and 90% RH, and the change in appearance was visually observed and evaluated according to the following evaluation criteria.
○: No visual change ×: Cloudiness or deformation is observed

-Light resistance-
A press-molded plate with a thickness of 1.0 mm was subjected to an accelerated exposure test for 100 hours in accordance with ASTM-G53, and the yellowing degree (ΔYI) before and after the YI (yellow index) test. ) Was measured. Here, an ultraviolet exposure tester (ATLAS-UVCON manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used. YI was measured according to JIS-K-7103. And it evaluated according to the following criteria.
ΔYI = (YI after 100 hours of UV exposure) − (YI before UV exposure)
○: ΔYI ≦ 1 Long-term light resistance is very good ×: 1 <ΔYI Long-term light resistance is poor

-Evaluation of warpage-
A light diffusion plate with a thickness of 2 mm obtained by extrusion molding was used, and it was cut into a length of 325 mm and a width of 420 mm to obtain a molded specimen 2. Next, the molded test piece 2 was conditioned for 200 hours under the conditions of temperature: 45 ° C. and relative humidity (RH): 95%, and then incorporated into the evaluation liquid crystal TV device 4 shown in FIG. The cold cathode tube 6 was turned on, and a displacement toward the cold cathode tube 6 and / or a displacement toward the transparent glass 10 side was measured using a laser displacement meter 8. In FIG. 2, reference numeral 12 denotes a reflector. Then, warpage was evaluated according to the following criteria.
○: The maximum displacement to the transparent glass E side is less than the reference value. Judged that the warpage is small. X: The maximum displacement to the transparent glass E side is greater than the reference value.

-Flexural modulus-
Using the test piece, the flexural modulus at 23 ° C. was measured using an autograph (manufactured by Shimadzu Corporation) according to JIS-K-7171. The determination criteria are as follows.
○: Flexural modulus is 2500 MPa or more ×: Flexural modulus is less than 2500 MPa

Example 1
For 100 parts by mass of the high molecular weight β-pinene polymer hydrogenated product (H1) obtained above, siloxane polymer particles (Tospearl 120: manufactured by GE Toshiba Silicones Co., Ltd., refractive index: 1.420, 1.0 part by mass of average particle diameter: 2 μm) and 0.1 part by mass of 2- (5-methyl-2hydroxyphenyl) benzotriazole, which is an ultraviolet absorber, were mixed with a Henschel mixer, and then an extruder. Then, a light diffusable molded article (P1) having a width of 1000 mm and a thickness of 2 mm was obtained at an extrusion resin temperature of 250 ° C.

-Comparative Example 1-
Example 1 except that ZEONOR 1060R (manufactured by ZEON Corporation) was used as the alicyclic polyolefin-based ring-opening polymer hydrogenated material instead of the β-pinene polymer hydrogenated material (H1) of Example 1. In the same manner as described above, a light diffusing shaped body (Q1) was obtained.

-Comparative Example 2-
Light diffusion in the same manner as in Example 1 except that Parapet GH-S (manufactured by Kuraray Co., Ltd.) was used as the polymethyl methacrylate instead of the β-pinene polymer hydrogenated product (H1) of Example 1. A molded product (Q2) was obtained.

  The physical properties of these three kinds of light diffusible molded bodies obtained were measured according to the above-described method, and the results are shown in Table 1 below.

  As is clear from the results of Table 1, both the Examples and Comparative Examples have large Haze values and good light diffusibility, but those of the Comparative Examples were large specific gravity and heavy light diffusible moldings. . On the other hand, Example 1 was a light diffusive molded article having a small specific gravity, a light deflection due to its own weight, and little deterioration in image quality due to the deflection when mounted on a large image display device. Moreover, although the thing of the comparative example 1 was small in water absorption and the dimensional stability by a water | moisture content was high, it was a result with a little low light resistance. On the other hand, although the thing of the comparative example 2 was favorable in light resistance, the water absorption was high, the dimensional change was large by the influence of moisture, and the fall of the image was large. From the results of the warp test, the comparative example was a result of large deformation due to heat when it was mounted on the image display device and the lamp was turned on, resulting in a decrease in image quality. Moreover, since the thing of the comparative example 1 has a low bending elastic modulus, the result was that the large light-diffusing molded body sheet was bent by its own weight. In addition, since the light diffusive molded article of Example 1 according to the present invention has a high flexural modulus, it is recognized that it is difficult to bend due to its own weight even if it is thin.

It is explanatory drawing which shows the method of calculating | requiring the glass transition temperature in an Example from a DSC curve. It is explanatory drawing which shows the outline of the apparatus used for evaluation of the curvature in an Example.

Explanation of symbols

2 Molded specimen 4 Liquid crystal TV device for evaluation 6 Cold cathode tube 8 Laser displacement meter 10 Transparent glass 12 Reflector

Claims (7)

Specific gravity of 0.85 or more and less than 1.0, glass transition temperature der 100 ° C. or higher is, and the weight average molecular weight of light-diffusing molded consisting 30,000 to 1,000,000 der Ru β- pinene polymer A light diffusable molded article having a thickness of 0.8 to 10 mm.
  The β-pinene polymer is hydrogenated, and ([number of olefinic double bonds hydrogenated] / [number of olefinic double bonds in the polymer before hydrogenation] 2) The value of x100 is 95% or more.   The light diffusing molded article according to claim 1 or 2, wherein a light diffusing agent is blended and contained.   The light diffusable molded article according to claim 3, wherein the difference between the refractive index of the β-pinene polymer and the refractive index of the light diffusing agent is 0.005 or more.   5. The light diffusable molded article according to claim 3, wherein 0.01 to 20 parts by mass of the light diffusing agent is blended with 100 parts by mass of the β-pinene polymer. .   The light diffusing molded article according to any one of claims 1 to 5, wherein a light diffusing means is integrally provided on the light emitting surface. An image display device comprising: a light source; and the light diffusing molded body according to any one of claims 1 to 6.

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