TW201022746A - Light conducting plate - Google Patents

Abstract

The invention provides a light conducting plate composed of extrusion resin boards, wherein heat distortion is difficult to occur even if it is used in thin and large picture of backlight. The light conducting plate is composed of extrusion resin boards with the thickness of 0.1-2.0 mm, the extrusion resin boards are placed in a thermal environment of 120 DEG C for 0.5 hours, and both the contraction percentage S1 (%) of the extrusion direction of the extrusion resin and the contraction percentage S2 (%) of the broad width direction of the extrusion resin board are 0-5%. Preferably the in-planedelay value of the extrusion resin board is below 200 nm.

Description

201022746 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a light guide plate formed by extruding a resin sheet. [Prior Art] A backlight used as a surface light source of a liquid crystal display has a direct type in which a light source such as a cold cathode tube or an LED is arranged side by side on the bottom surface and emits φ light through a light diffusing plate, and a cold cathode tube or an LED or the like. The light source is disposed on an edge portion of the transparent plate called a light guide plate, and the light is emitted from the edge of the light guide plate by the dot ink printing or the pattern shape provided on the back surface to emit light to the front side light type. Heretofore, from the viewpoint of improving the brightness of the backlight, the direct type is the mainstream. However, in recent years, a thin and high-intensity LED is often used as a light source, or a thinner liquid crystal display is used, and the ratio of the side light type is increased. On the other hand, with the large screen of the liquid crystal display, a thin and wide-area light guide plate can be expected. In the past, most of the light guide plates have been produced by injection molding (for example, φ is referred to Patent Documents 1 and 2), but there is a problem that the injection molding does not allow smooth processing as it becomes a wide area. [Patent Document 1] JP-A-9-1 3 1770 (Patent Document 2) JP-A-2008-20747

1J 容内明发 rL Instead of injection molding, it is advantageous to manufacture a thin and large-area light guide plate when extrusion molding is used. However, when high-output LEDs are used as light sources in recent years, the number of LEDs with large screens also increases. Since the temperature near the light source will increase by 201022746, the light guide plate may be deformed. Therefore, there is a phenomenon that light leakage occurs from the light source, and the brightness of the picture is lowered. SUMMARY OF THE INVENTION An object of the present invention is to provide a light guide plate which is made of an extruded resin sheet which is thin and which is not easily thermally deformed by the backlight of a liquid crystal display which is used for a large screen. The light guide plate of the present invention is a light guide plate formed by extruding a resin plate having a thickness of 0.1 to 2.0 mm, and when the extruded resin plate is placed in a thermal environment of 120 ° C for 0.5 hour, the pressure of the extruded resin plate is pressed. The shrinkage ratio S1 (%) in the outgoing direction and the shrinkage ratio S 2 (%) in the width direction are all 0 to 5%. When the light is introduced into the light guide plate, the phenomenon that the light is reduced by the coloring is suppressed, and the in-plane retardation of the extruded resin sheet is preferably 200 nm or less. [Effects of the Invention] The light guide plate made of the extruded resin sheet of the present invention is thin and has an effect of not being easily thermally deformed even when the backlight of the liquid crystal display used for a large screen is used. The light guide plate can be used, for example, as a thin backlight for carrying an information terminal, a portable game machine, a notebook computer, or the like. The light guide plate of the present invention is formed by extruding a resin plate. The resin constituting the extruded resin sheet is not particularly limited as long as it can be melt-processed, and examples thereof include a polychlorovinyl resin, an acrylonitrile-butadiene-styrene resin, and a low resin. Density polyethylene resin, high density polyethylene resin, linear low density polyethylene resin, polystyrene resin, polypropylene resin, acrylonitrile-styrene resin, cellulose acetate resin, ethylene vinyl acetate Ester resin, propylene-acrylonitrile-styrene resin, propylene--6- 201022746 chlorinated polyethylene resin, ethylene-vinyl alcohol resin, fluororesin, methyl methacrylate resin, methyl methacrylate-styrene Resin, polyacetal resin, polyamide resin, polyethylene terephthalate resin, aromatic polycarbonate resin, polyfluorene resin, polyether oxime resin, methylpentene resin, polyacrylate resin, poly Butylene terephthalate resin, resin containing ethylenically unsaturated monomer unit having an alicyclic structure, polyphenylene sulfide resin, polyphenylene oxide resin, polyetheretherketone resin, etc. Or in addition to industrial Φ plastic, polyvinyl chloride-based elastomer chlorinated polyethylene, vinyl-ethyl acrylate resin, thermoplastic polyurethane elastomer, thermoplastic polyester elastomer, ionic polymer resin A rubbery polymer such as a styrene-butadiene block polymer, an ethylene-propylene rubber, a polybutadiene resin, or an acrylic rubber may be used alone or in combination of two or more. For example, a resin mixture composed of a polycarbonate resin and a trace amount of methyl methacrylate resin can be used. Among these resins, a methyl methacrylate-based resin containing 50% by mass or more of a methyl methacrylate unit having excellent optical properties is contained, and 100 parts by weight of a rubbery polymer is added to 100 parts by weight of the above methyl methacrylate-based resin. The following resin composition, a styrene resin containing 50% by mass or more of a styrene unit, and a resin composition of 100 parts by weight or less of a rubbery polymer added to 100 parts by weight of the styrene resin, and an aromatic polycarbonate A resin or a resin containing an ethylenically unsaturated monomer unit having an alicyclic structure is preferred. One type of resin may be used as the resin constituting the resin sheet, and one type of one layer may be used as the resin constituting the resin plate. Two types of resin may be used as the 201022746 two-layer board or two types of three-layer boards. . For example, an extruded resin sheet having a layer made of an aromatic polycarbonate resin as a main layer and a layer made of a methyl methacrylate resin in the surface layer may be mentioned.

The methyl methacrylate-based resin containing 50% by mass or more of the methyl methacrylate unit is a polymer containing methyl methacrylate unit as a monomer unit, preferably 70% by mass or more, and 1% by mass. Also. The polymer of 100% by mass of methyl methacrylate unit is a methyl methacrylate alone polymer obtained by polymerizing methyl methacrylate alone. Further, the methyl methacrylate polymer containing 50% by mass or more of the methyl methacrylate unit may be a copolymer of one or more kinds of monomers which are copolymerizable with methyl methacrylate. The monomer obtained by copolymerization with methyl methacrylate may, for example, be a methyl acrylate other than methyl methacrylate. Examples of the methacrylates include ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, and 2-ethyl methacrylate. Hexyl hexyl ester, 2-hydroxyethyl methacrylate, and the like. Further, examples thereof include methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and the like. Substituted styrenes such as unsaturated acids such as acrylates, methacrylic acid and acrylic acid, halogenated styrenes such as chlorostyrene and bromostyrene, alkylstyrenes such as vinyltoluene and α-methylstyrene Acrylonitrile, methacrylonitrile, anhydrous maleic acid, phenylmaleimide, cyclohexylmaleimide, etc. The so-called rubbery particles in the present invention may be exemplified by an acrylic multilayered layer-8. 201022746 A graft copolymer of a polymer, or a rubbery polymer, and an ethylenically unsaturated monomer. Among them, a graft copolymer composed of 5 to 80 parts by weight of a rubbery polymer and 95 to 20 parts by weight of an acrylic unsaturated monomer is also preferred. The acrylic multilayer structure polymer preferably contains the layer of the elastomer in an amount of from 2 to 60 parts by weight. In the acrylic multilayer polymer, it is preferred that the outermost layer has a hard layer, and the innermost layer has a hard layer. In the φ acrylic multilayer polymer, the layer formed of the polymer is a multilayer body composed of a particulate polymer having a structure of two or more layers laminated, and at least one layer of the layer formed of the polymer. A multilayer body of a polymer of a propylene acrylate and/or methacrylate. The rubbery polymer is a copolymer containing an acrylate and/or a methacrylate and a compound containing two or more unsaturated groups. The ethylenically unsaturated monomer has an unsaturated bond at the molecular end, and the unsaturated bond is a monomer of an ethylene skeleton (-CH = CH2). The φ acrylic unsaturated monomer is an acrylate and/or methacrylate having an unsaturated bond at the molecular terminal. a resin constituting a layer formed of an elastomer, which is an acrylic polymer having a glass transition point (Tg) of less than 25 ° C, and is composed of a lower alkyl acrylate and a methacrylate 'lower alkoxy acrylate. One or more monoethylenically unsaturated monomers such as cyanoethyl acrylate, acrylamide, hydroxy lower alkyl acrylate, hydroxy lower methacrylate, acrylic acid, methacrylic acid, and allyl methacrylic acid An ester and/or a polymer of the aforementioned polyfunctional monomer. -9- 201022746 The so-called hard layer is a polymer composed of acrylate and/or methacrylate. The polymer constituting the hard layer is an acrylic polymer having a Tg of 25 ° C or higher, a single polymer having a propylene methyl phthalate having a carbon number of 1 to 4, or a carbon number of 1 to 4. Copolymers of methacrylic acid esters of other hospital bases and other copolymer components are preferred. Among the copolymers of the alkyl methacrylate having a carbon number of 1 to 4 alkyl groups and other copolymer components, the alkyl methacrylate having a carbon number of 1 to 4 alkyl groups is preferable as the main component. Specifically, the copolymer of an alkyl methacrylate having a carbon number of 1 to 4 alkyl groups and other copolymer components is an alkyl methacrylate unit having a carbon number of 1 to 4 alkyl groups and 95 parts by weight. More than % is better. As other copolymer components obtained by copolymerization with an alkyl methacrylate having a carbon number of 1 to 4 alkyl groups, other alkyl methacrylate or alkyl acrylate, styrene, substituted styrene may be used. A monofunctional monomer such as acrylonitrile or methacrylonitrile, or a polyfunctional monomer may be further used. In the present specification, the monofunctional monomer is a monomer having one acryl fluorenyl group in the molecule, and the polyfunctional monomer is a monomer having two or more acrylonitrile groups in the molecule. Examples of the rubber-like particles include those described in JP-A-59-275, pp. 6-80739, and JP-A-49-23292. In the graft copolymer of 5 to 80 parts by weight of the rubbery polymer and 95 to 20 parts by weight of the ethylenically unsaturated monomer, as the rubbery polymer, for example, polybutadiene rubber or acrylonitrile-butyl can be used. Diene copolymer rubber, -10-201022746 diene rubber such as styrene-butadiene copolymer rubber, polypropyl acrylate, poly-2-ethylhexyl propylene rubber, and vinyl-propylene-non-conjugated Examples of the mixture of the diene rubber-like polymer used in the graft copolymerization and the mixture thereof include styrene, propyl acrylate, and the like. As their graft copolymers, the copolymer of 55-147514 or the gong 47_974 φ φ branch copolymer. When the rubber-like polymer is used in combination with the methyl acrylic acid resin, the dispersion ratio of the rubber-like polymer is preferably from 3 to 50 parts by weight based on 100 parts by weight of the ester resin or the styrene resin. The rigidity of the plate is sometimes reduced more than 1 inch. a styrene-based monofunctional monomer unit containing 50% by mass or more of a styrene unit as a main component of a poly-p-vinyl-based monofunctional monomer unit of 50% by mass or more of a single polymer of a singular monofunctional monomer or benzene And one or more types of individual officials that can be copolymerized therewith. The styrene-based monofunctional monomer has, for example, a free radical in a molecule such as an alkyl styrene such as a halogenated styrene α-methylstyrene such as chlorostyrene or bromostyrene. The acrylic resin such as the styrene-based monofunctional monomer and the co-gelable or polybutyl acrylate acrylate is polymerized. The methylenic unsaturated monomeric nitrile or the alkyl group (for example, the methyl ester type or the styrene type described in JP-A-ZOKAI and the like) can be used in an amount of 0 to 100% by weight for methacrylic acid. In the case of the resin, the resin-based vinyl resin is a benzene compound, for example, a benzene polymer, or a copolymer of a styrene-based monofunctional monomer-energy monomer. a compound having a double bond of styrene and the like such as ethylene. The polymerized monofunctional monomer-11-201022746 is a molecule having one radical polymerizable double bond in the molecule, and the double bond can be combined with a styrene monofunctional monomer. Examples of the compound to be copolymerized include methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, and methyl group. 2-ethylhexyl acrylate, 2-hydroxyethyl methacrylate and other methacrylates, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, acrylic acid 2-ethyl An acrylate such as an ester or 2-hydroxyethyl acrylate or an acrylonitrile is preferably used as a methacrylate such as methyl methacrylate. The aromatic polycarbonate resin generally has one or more kinds of dihydric phenols and carbonates. The polymer obtained by the reaction of the interfacial polycondensation method or the melt transesterification method may be a polymer obtained by polymerizing a carbonate prepolymer by a solid phase transesterification method, or by a cyclic carbonate. A polymer obtained by polymerizing a compound by ring-opening polymerization. Examples of the dihydric phenol used therein include hydrogen, resorcin, and 4,4'-dihydroxydiphenyl. Bis(4-hydroxyphenyl)methane, bis{(4-hydroxy-3,5-dimethyl)phenyl}methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1_double (4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis{(4-hydroxy-3-methyl) Phenyl}propane, 2,2-bis{(4-hydroxy-3,5-dimethyl)phenyl}propane, 2,2-bis{(4-hydroxy-3,5-dibromo)phenyl }propane, 2,2-bis{(3-isopropyl-4-hydroxy)phenyl}propane, 2,2_double {(4-hydroxy-3-phenyl)phenyl}propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-3-methylbutane , 2,2-bis(4-hydroxyphenyl)-3,3-dimethylbutane-12- 201022746, 2,4-di-(4-predylphenyl)-2-methylbutyl, 2 ,2-bis(4-predomylphenyl)pentane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, anthracene, bis(4-hydroxyphenyl)cyclohexane, 1,1·bis(4-hydroxyphenyl)-4-isopropylcyclohexane, 1,1-bis(4-hydroxyphenyl)·3,3,5-trimethylcyclohexane, 9, 9_bis(4-hydroxyphenyl)anthracene, 9,9-bis{4-hydroxy-3-methyl)phenyl)anthracene, α,α'-bis((4-hydroxyphenyl)-0-di Isopropylbenzene, α,α,-bis(4-hydroxyphenyl)-m-diisopropylbenzene, α,α'-bis(4.hydroxyphenyl)-ρ_diisoφpropylbenzene, 1,3-bis(4-hydroxyphenyl)·5,7-dimethyl adamantane, 4,4,-dihydroxydiphenyl maple, 4,4′-dihydroxydiphenyl argon, 4, 4,-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4,-dihydroxydiphenyl ether, and 4,4'-dihydroxydiphenyl ester. Wherein it is selected from the group consisting of bisphenol Α ' 2,2-bis((4-hydroxy-3-methyl)phenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-dual ( 4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)-3,3-dimethylbutane, 2,2-bis(4-hydroxyphenyl) A Pentane, 1,1-bis(4-hydroxyphenylφ)-3,3,5-trimethylcyclohexane and α,α'-bis(4-hydroxyphenyl)-m-diisopropyl A single polymer or copolymer obtained by grouping at least one bisphenol of a benzene group, particularly a single polymer of bisphenol A, u-bis(4-hydroxyphenyl)-3,3,5-three a copolymer of methylcyclohexane and bisphenol A, or 2,2·bis((4-hydroxy-3-methyl)phenyl)propane and α,α'-bis(4-hydroxyphenyl)-m A copolymer of at least one divalent phenol selected from diisopropylbenzene and bisphenol A is preferred. As the carbonate precursor, for example, a carbonyl halide, a carbonate or a halogenated formate can be used, and specific examples thereof include phosgene, diphenyl carbonate or a dihalogenated formate of divalent -13-201022746 phenol. Examples of the resin containing an ethylenically unsaturated monomer unit having an alicyclic structure include a raw spintenyl polymer, a monocyclic cyclic olefin polymer, a cyclic conjugated diene polymer, and a vinyl ester. A cyclic hydrocarbon polymer, and these hydrides. Among them, from the viewpoint of light permeability, a raw ribene-based polymer hydride, a vinyl alicyclic hydrocarbon-based polymer or a hydride thereof is preferred, and a raw snail-based polymer hydride is preferred. good. The resin containing an ethylenically unsaturated monomer unit having an alicyclic structure is characterized in that it has a oxime-based structure in a repeating unit of the polymer, and the alicyclic structure may be in the main chain and/or the side chain. From the viewpoint of light permeability, a polymer having an alicyclic structure in the main chain is preferred. In the extruded resin sheet, since sufficient durability is provided, it is preferred to contain one or more kinds of ultraviolet absorbers. The content of the ultraviolet absorber is usually 0.001 to 1 part by weight, preferably 0.01 to 0.5 part by weight, more preferably 0.01 to 0.1 part by weight, per part by weight of the thermoplastic resin. When the content of the ultraviolet absorber is less than 0.001 part by weight, the durability of the light guide plate may be insufficient, or when it exceeds 1 part by weight, the ultraviolet absorber may be easily blended on the surface of the light guide plate to make the appearance of the light guide plate got damage. As the ultraviolet absorber, an ultraviolet absorber having a maximum absorption wavelength in the range of 25 to 3 2 Onm is preferable, and a maximum absorption wavelength (hereinafter referred to as "Xm ax") in the range of 250 to 800 nm is the maximum absorption. The ultraviolet absorber of the wavelength can improve the durability of the light guide plate, and can also suppress the coloration of the light guide plate caused by the absorption of visible light of the ultraviolet absorber. Further, as the ultraviolet absorber, the molar absorption coefficient (hereinafter referred to as "sniax" in the above -14 - 201022746) in the maximum absorption wavelength is 10,000 mol_icm-1 or more, particularly, the ultraviolet absorber of 15,000 τηη, ητΐ or more, or the molecular weight. The ultraviolet absorber (hereinafter referred to as "Mw") of 4 Å or less is preferable from the viewpoint of the use weight reduction. Further, as the ultraviolet absorber, for example, a benzophenone-based ultraviolet absorber, a cyanoacrylate-based ultraviolet absorber, a salicylic acid-based ultraviolet absorber, a nickel-salt-based ultraviolet absorber, or a benzoate-based ultraviolet absorber can be used. The φ absorbing agent, the benzotriazole-based ultraviolet absorbing agent malonate-based ultraviolet absorbing agent, the uric acid guanamine benzene-based ultraviolet absorbing agent, and the acetate-based ultraviolet absorbing agent. Among them, a benzophenone-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, a malonate-based ultraviolet absorber, an oxalic acid amide-based ultraviolet absorber, and an acetate-based ultraviolet absorber are preferable. The malonate-based ultraviolet absorber, the urethane phthalate-based ultraviolet absorber, and the acetate-based ultraviolet absorber can improve the durability of the light guide plate and suppress the coloration of the light guide plate due to the visible light absorption of the ultraviolet absorber. Φ As the benzophenone-based ultraviolet absorber, for example, 2,4-dihydroxybenzophenone (Mw: 214, Xmax: 288 nm, smax: MlOOmol.icm-1) 2-carbyl-4-methyl Oxybenzophenone (Mw: 228, Xmax: 289 nm, smax: ΜΤΟΟπιοΓ1^!!·1, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (Mw: 308, Xmax: 292 nm) , Emax · 1 25OOmol '1 cm'1 ) ' 2-hydroxy-4-octyloxybenzophenone (Mw: 3 26, Xmax __ 291nxn, smax: lSSOOmol-'cm'1 ), 4-12A矽 alkoxy-2-hydroxybenzophenone (Mw : 3 83 , : 290 nm > smax : 1 6200 m 〇r1 cm " 1 ) , 4-benzyloxy-2-pyridylbenzophenone (Mw : 304, kmax: 289 nm, smax ·· -15- 201022746 1 5900mol'•cm·' ) , 2,2 '-dihydroxy-4,4 '-dimethoxybenzophenone (

Mw : 274, Xmax '· 289 nm, smax : 1 1 8 OOmol '1 cm'1 ) , 1,6-bis(4-benzylmercapto-3-hydroxyphenoxy)-hexane (Mw: 511, kmax : 290 nm ' Emax : 30 1 OOmol '1 cm'1 ) , 1,4-bis(4-benzylidene-3-hydroxyphenoxy)·butane (Mw ·· 483, Xmax : 290 nm, smax : 28500m〇r1cm*1) and so on. Examples of the cyanoacrylate-based ultraviolet absorber include ethyl 2-cyano-3,3-diphenylacrylate (1): 277, human 111!^: 30511111, smax: ΙδόΟΟιηοΓ^ηΓ1. ]-Ethylhexyl 2-cyano-3,3-diphenylpropionate (Mw: 3 62, ληΐ3χ: 307 nm, £max: 14400 m〇r) cnT1), etc. As a salicylate-based ultraviolet absorption Examples of the agent include phenyl salicylate (Mw: 214, Xmax: 312 nm, emax: SOOOmol '1 cm'1 ), and 4-tributylphenyl salicylate (Mw: 270, Xmax: 312 nm, emax: 5 4 0 0 m o 1-1 cm-], etc. As the nickel-salt-type ultraviolet absorber, for example, (2,2'·thiobis(4-t-octylbenzoate)) 2-ethylhexylamine nickel (II) (Mw: 629, λη, 3χ: 298 nm, emax: 6600 mol1 cm1), etc. As a benzoate-based ultraviolet absorber, for example, 2', 4'-di -T-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate (Mw: 436, Xmax: 267 nm'smax: 2020011101 ^1111), etc. As a benzotriazole-based ultraviolet ray As the absorbent, for example, 2-(2-hydroxy-5-methylphenyl) -2H-benzotriazole (Mw: 225, Xmax: 300 nm, max -13800 mol icm)), 5-chloro-2-(3,5-di-t-butyl-2-yl-based 201022746 phenyl)- 2H-benzotriazine (Mw: 358, Xmax: 312 nm, smax: 1 46 0 0mo 1'1 cm'1 ), 2-(3-tert-butyl-2-yl-5-methylphenyl) -5-Chloro-2H-benzotriazole (Mw: 316, Xmax: 3 54 nm, smax: MSOOmol^cm-1), 2-(3,5-di-tripentyl-2-hydroxyphenyl) )-211-benzotriazole (Mw: 352, Xmax: 305 nm, Smax: ISSOOnioldcm·1), 2-(3,5-di-t-butyl-2-hydroxyphenyl)-211-benzotriene Azole (\1 evaluation: 323, Xmax: 303 nm, smax: ΒόΟΟιηοΓ1.!!!·1), 2-(2H-benzene φ-triazol-2-yl)-4-methyl-6· (3,4 , 5,6-tetrahydrophthalic acid imine methyl) (Mw : 3 88 , Xmax : 304 nm , 8 max : 141 OOmol '1 cm " 1 ), 2-(2-hydroxy-5-third Octylphenyl)-211-benzotriazole (]^%: 323, λΜ3χ: 301 nm, 8max: 14700 m〇r'cm'1) and the like. As the malonate-based ultraviolet absorber, 2-(1-arylalkylene)malonate can be used, and among them, the compound represented by the following general formula (1) is also preferred.

/CO#1 CH=C (1) co2r2 (wherein X1 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. 'R1 and R2 each represent the same or different groups. Each represents an alkyl group having 1 to 6 carbon atoms. In the above general formula (1), the alkyl group represented by X1 and the alkyl group of the alkoxy group represented by oxime 1 may be linear or branched, and examples thereof include a methyl group and an ethyl group-17-201022746. Propyl, isopropyl, n-butyl, isobutyl, t-butyl, tert-butyl, and the like. X1 is preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and the substitution position of X1 is preferably a para position. Further, in the above general formula (1), the alkyl groups represented by R1 and R2 may each be linear or branched, and examples thereof include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, and a different form. Butyl, second butyl, tert-butyl, and the like. Each of R1 and R2 is preferably an alkyl group having 1 to 4 carbon atoms. The compound represented by the above general formula (1) is particularly preferably 2-(p-methoxybenzylidene)malonic acid dimethyl (Mw: 250, kmax: 3 08 nm, smax: 24200 mol_1 cm_). As the guanamine benzene-based ultraviolet absorber, alkoxy oxalic acid amide benzene can be used, and among them, the compound represented by the following general formula (2) is preferably used [Chemical 2]

(2) (wherein R3 and R4 are the same or different groups each, and each represents an alkyl group having 1 to 6 carbon atoms). In the above general formula (2), the alkyl groups represented by 113 and R4 may each be linear or branched, and examples thereof include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. , a second butyl group, a third butyl group, and the like. It is preferred that R3 and R4 each have an alkyl group having 1 to 4 carbon atoms, and R3 and the substitution positions are preferably from -18 to 201022746. As the compound represented by the above formula (2), particularly, 2-ethoxy-2-ethyl oxalic acid amide (Mw: 312, Xmax: 298 nm, smax: 166,700 mol_1 cm·1 is preferred. As the ultraviolet absorbing agent, 2_(1-arylalkylene) acetate can be used, and among them, a compound represented by the following general formula (3) is preferably used.

[化3]

X

(3) (wherein, X2 represents a hydrogen atom, an alkyl group or an alkoxy group, and R5 represents an alkyl group). The alkoxy group as the substituent X2 may be linear or branched, and examples thereof include methoxy. a carbon number of 1 to 6 such as a group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, an isobutoxy group, a second butoxy group, a third butoxy group, and a n-pentyloxy group. The alkoxy group is preferably an alkoxy group having a carbon number of from 1 to 4. The alkyl group may be linear or branched, and examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, second butyl group, tert-butyl group, and n-pentyl group. An alkyl group having a carbon number of from 1 to 6 such as an n-hexyl group is preferably an alkyl group having a carbon number of from 1 to 4, more preferably a methoxy group. The substituent X2 is preferably an alkoxy group. The alkyl group of the substituent R5 is generally an alkyl group having a carbon number of 1 to 1 Å, and examples thereof include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and the like. Dibutyl 't-butyl'-n-pentyl, n-hexyl, n--19 - 201022746 heptyl, n-octyl, n-decyl, n-decyl, i-methylpentyl, i-ethylpentyl, An alkyl group having a carbon number of from 1 to 10, such as a 1-methylhexyl group or a 2-ethylhexyl group, is preferably a methyl group or a 2-ethylhexyl group. In order to further improve the durability in the resin sheet, it is preferred to contain one or more kinds of hindered amines, and particularly preferably a compound having a 2,2,6,6-fourth-based piperidine skeleton. The content of the hindered amine is usually 2 parts by weight or less, preferably 〇. 〇 i 〜1 by weight, of the ultraviolet absorber contained in the extruded fat plate. 0 As a hindered amine, for example, dimethyl succinate / 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly(( 6-( 1,1,3,3-tetramethylbutyl)imide-i,3,5-triazine-2,4-diyl)(( 2,2,6,6-tetramethyl- 4-piperidinyl)imine)hexamethyl ((2,2,6,6-tetramethyl-4-piperidinyl)imide))' 2-(2,3-di-third 4-(4-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl), 2-(3,5-di· Tert-butyl-4-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl), N,N'-double (3-Aminopropenyl) Ethyldiamine/2,4-bis(n-butyl-1(1,2,2,6,6-pentamethyl-4-piperidyl)amino) -6-chloro-1,3,5-triazine condensate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, succinic acid bis(2,2,6 , 6-tetramethyl-4-piperidinyl), or a compound represented by the following general formula (4). -20- (4) (4) 201022746

(wherein Y represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a carboxyalkyl group having 2 to 20 carbon atoms, an alkoxyalkyl group having 2 to 25 carbon atoms or an alkoxycarbonyl group having 3 to 25 carbon atoms; alkyl). In the above general formula (4), two alkyl groups of the alkyl group, the carboxyalkyl group and the alkoxyalkyl group (the alkyl group of the alkoxy group and the alkyl group substituted by the alkoxy group), and the alkoxy group are shown. The two alkyl groups (the alkyl group of the alkoxy group and the alkyl group substituted by the alkoxycarbonyl group) in the carbonylcarbonyl group may each be linear or branched. The hydrazine is preferably a hydrogen atom or an alkoxycarbonylalkyl group having 5 to 24 carbon atoms, more preferably a hydrogen atom or an alkoxycarbonylethyl group. The alkoxycarbonylethyl group may, for example, be dodecyloxycarbonylethyl, tetradecyloxycarbonylethyl, hexadecanoyloxycarbonylethyl or octadecyloxycarbonylethyl. Further, the extruded resin sheet may contain one or more additives other than the ultraviolet absorber or the hindered amine, and may contain, for example, a light diffusing agent, a matting agent, an antioxidant, a releasing agent, a flame retardant, an antistatic agent, and the like. . The extruded resin sheet in the present invention has a thickness of 〇_1 to 2.0 mm, preferably 0.2 to 1.5 mm, more preferably 0·3 to 1. 3 mm. When the thickness is less than 0.1 mm, the area of the edge portion of the light guide plate becomes small, and the light source cannot introduce sufficient light into the light guide plate. When the thickness exceeds 2.0 mm, the weight of the light guide plate becomes large. The thickness of the extruded resin sheet is such that the thickness of the molten thermoplastic resin 4 extruded from the mold 3 as described later -21 - 201022746 can be adjusted by the interval of the two cooling rolls 5 or the like. In the present invention, the shrinkage ratio S 1 (%) in the extrusion direction of the extruded resin sheet and the shrinkage ratio S 2 in the width direction when the extruded resin sheet is left in a hot environment at 120 ° C for 0.5 hour is placed. (%) is 〇 5%, preferably 1 to 4%, more preferably 1 to 3%. The shrinkage ratios S 1 and S 2 are negative numbers, that is, when the light guide plate is used, when the light guide plate is used, the light guide plate is swollen by the heat of the light source, and the light guide plate is not only deformed by itself for the backlight case, The backlight unit of the 〇 light guide plate is also prone to deformation. Further, when the shrinkage ratios S1 and S2 exceed 5%, when the lighting source increases the internal temperature, the contraction of the light guide plate may become large or may be deformed, so that light leakage may occur in the light source portion, which may cause a decrease in brightness. Sex. The shrinkage rates SI and S2 are as follows. In other words, according to JIS-K7133, a square having a side length of 120 mm was cut out from the extruded resin sheet as a test piece, and a square having a side of 100 mm was placed in a state in which a pair of opposite sides and a direction in which the extruded resin sheet was pressed out were parallel. , with the edge of the line © depicting. Next, the test piece was placed in a hot air circulating oven having a temperature of 120 ° C in the bath for 0.5 hour and heated, and taken out from the oven and cooled sufficiently in the air to measure the side length of the square. At this time, the length of the extrusion direction of the resin plate is taken as the average 値 of the length of the two sides, and the length in the direction of the orthogonal direction (width direction) also serves as the average 値 of the length of the two sides. On the average 各 of each length, the respective shrinkage ratio S1 in the extrusion direction and the shrinkage ratio S2 in the width direction were calculated by the following formula (i). -22- 201022746 [Number 1] Shrinkage (%) = (( Α - Β) / Α) χ 100 ... (i) A: Length of the extrusion direction or width direction before heating 値 B: After heating The average length 値 in the extrusion direction or the width direction is a method in which the shrinkage ratios SI and S2 in the extrusion direction and the width direction are within the above range, and examples thereof include the following methods. That is, a method in which a sheet which is formed by a general pressure φ is passed through a region other than a deflection temperature under load of a thermoplastic resin constituting the sheet to be a desired shrinkage range or which is to be extruded by a mold The molten thermoplastic resin is a method of forming a film while supporting a high-rigidity metal roll and an elastic roll having a metal film on the outer peripheral portion. In the above method, it is preferred to use a method in which a molten thermoplastic resin is held by a metal roll and an elastic roll to form a film. Hereinafter, an embodiment of a method for producing an extruded resin sheet of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic explanatory view showing a method of manufacturing the extruded resin sheet of the embodiment. Fig. 2 is a schematic cross-sectional view showing the metal roll and the elastic roll of the embodiment. The extruded resin sheet of the present embodiment can be produced by a general extrusion molding method. That is, as shown in Fig. 1, the thermoplastic resin to be the base material is heated and melted by the extruder 1 and/or the extruder 2, and then melt-kneaded by a mold 3, and is generally pressed into a plate shape by the mold 3. When the extruded resin sheet is used as a multi-layer structure, it can be produced by a co-extrusion molding method. In other words, for example, the thermoplastic resin as the substrate, -23-201022746, and the other thermoplastic resin to be laminated from the extruder 2 may be co-extruded by the extruder 1 . In the case of the co-extrusion, the thermoplastic resin is melted and kneaded by the respective extruders 1, 2, and is extruded from the co-extrusion molding die 3 to be laminated. Just fine. Examples of the extruders 1, 2 include a one-axis extruder, a two-axis extruder, and the like. Further, the number of the extruders is not limited to two, and may be three or more. As the mold 3, a T-plastic mold is generally used, and a single-layer mold in which a thermoplastic resin is laminated in a single layer can be used, for example, a supply sleeve mold, a composite u-division mold, and the like, and each of the independent self-pressing machines 1. (2) A multilayer mold in which two or more kinds of thermoplastic resins are laminated and pressed together by pressure feeding. As described above, the molten thermoplastic resin 4 which has been extruded from the mold 3 is cooled by the two cooling rolls 5 which are disposed oppositely in the horizontal direction, and the extruded resin sheet 11 is obtained. As shown in Fig. 2, the cooling roll 5 is composed of a high-rigidity metal roll 6 and an elastic roll 7 having a metal film 9 on its outer peripheral portion, that is, a metal elastic roll 7. At least one of the metal roller 6 and the metal elastic roller 7 is connected by a rotational driving means such as a motor, and the two rollers are configured to rotate at a predetermined peripheral speed. The high-rigidity metal roll 6 is a take-up roll wound by a plate-shaped thermoplastic resin held between the metal roll 6 and the metal elastic roll 7. The metal roller 6 is not particularly limited, and a general metal roller used in extrusion molding in the past can be used. As a specific example, a drill roll, a spiral roll, etc. are mentioned. The surface state of the metal roller 6 may be, for example, a mirror surface, or may be a pattern or a bump. The metal elastic roller 7 is a cylindrical metal film 9 which is disposed so as to cover the shaft roller 8 which is provided in a substantially cylindrical shape and is freely rotatable, and which is provided with the outer peripheral surface of the shaft roller 8 and which is in contact with the molten thermoplastic-24-201022746 resin 4. A fluid 10' is sealed between the isometric roller 8 and the metal film 9, whereby the metal elastic roller 7 can exhibit elasticity. The shaft roller 8 is not particularly limited. For example, it may be made of stainless steel or the like. The metal film 9 is made of, for example, stainless steel, and the thickness is preferably about 2 to 5 mm. It is preferable that the metal thin film 9 has flexibility such as buckling property or flexibility, and it is preferable to have a seamless structure without a welded joint. The metal elastic roller 7 having the metal film 9 has excellent durability, and only the φ metal film 9 is mirror-finished, and the same processing method as that of the general mirror surface can be applied to the metal film 9 to impart a pattern or irregularities. It is a roller that transfers the shape and can be used at will. The metal film 9 is fixed to both end portions of the shaft roller 8, and a fluid 10 is sealed between the shaft roller 8 and the metal film 9. Examples of the fluid 1A include water, oil, and the like. By controlling the temperature of the fluid 1 ,, the temperature of the metal elastic roller 7 can be controlled, whereby the resulting extruded resin sheet can be easily controlled to a desired shrinkage rate, and productivity can be improved. For the aforementioned temperature control, for example, a known control method such as φ PID control or ON-OFF control can be employed. Instead of the fluid 10, a gas such as air can be used. When the molten thermoplastic resin 4 is held between the metal roll 6 and the metal elastic roll 7, the metal elastic roll 7 is in contact with the molten thermoplastic. The resin 4 is elastically deformed along the outer peripheral surface of the metal roll 6, and the metal elastic roll 7 and the metal are formed. The roller 6 is brought into contact with the molten thermoplastic resin 4 at a predetermined contact length L. As a result, the metal roll 6 and the metal elastic roll 7 are pressed against the molten thermoplastic resin 4 in a surface contact manner, and the molten thermoplastic resin 4 held by the rolls is uniformly pressed into a planar shape to form a film. When the film formation is carried out in this way, the deformation remaining in the resin sheet of 25-201022746 can be suppressed. As a result, the shrinkage ratios SI and S2 in the extrusion direction and the width direction of the obtained extruded resin sheet 1 i are within the above range. In order to obtain the lengths of the extrusion direction of the obtained resin sheet 11 and the orthogonal direction, that is, the shrinkage ratios SI and S2 in the width direction, it is preferable that the contact length L is 1 to 20 mm. It is preferable to use 1 to l 〇 mm, preferably 1 to 7 mm. Therefore, the metal elastic roller 7 is only required to have elasticity such that the metal elastic roller 7 is elastically deformed so as to have such a contact length l. In order to set the contact length L to a predetermined value, for example, only the thickness of the @metal thin film 9 and the amount of the fluid 10 to be sealed may be adjusted. Further, the contact length L is the length of the line connecting the point at which the molten metal resin roller 7 and the metal roll 6 come into contact with each other and the point at which the contact ends. After the sheet-shaped thermoplastic resin held between the metal roll 6 and the metal elastic roll 7 is taken up by the metal roll 6, the drawn roll is cooled by a drawing roll (not shown), thereby obtaining an extruded resin. Board 1 1. Next, an embodiment of the method of producing the extruded resin sheet according to the present invention will be described. Fig. 3 is a schematic cross-sectional view showing the elastic roller of the embodiment. In Fig. 3, the same components as those in Fig. 1 and Fig. 2 are denoted by the same reference numerals, and their description is omitted. As shown in Fig. 3, the metal elastic roller 15 according to the present embodiment is a metal elastic roller covered with a cylindrical metal film 17 by a cylindrical shape of the outer peripheral surface of the shaft roller 16 which is provided in a substantially cylindrical shape. . The shaft roller 16, for example, is a rubber roller made of rubber such as ruthenium rubber, whereby the metal elastic roller 15 of -26-201022746 can exhibit elasticity. By adjusting the hardness of the rubber, the contact length L can be made to a predetermined value. The metal film 17 is made of, for example, stainless steel, and the thickness is preferably about 0.2 to 1 mm. In order to make the metal elastic roller 15 a temperature-controllable structure, for example, only the backup cooling roller may be attached to the metal elastic roller 15. The other configuration is the same as that of the above embodiment, and thus the description thereof is omitted. The in-plane retardation φ of the thus obtained extruded resin sheet is preferably 200 nm or less. When the in-plane retardation 値 exceeds 200 nm, when the light guide plate emits light, the light is colored to lower the brightness. The in-plane retardation is as described later, and is measured by a micro-area complex refractometer. When the in-plane retardation 値 is 200 nm or less, when the molten thermoplastic resin 4 is held and formed by the metal roll 6 and the metal elastic roll 7, the molten thermoplastic resin 4 is held in two rolls before being cooled and solidified or cooled and solidified. It is better. Specifically, the surface temperature (Tr ) of the metal roll 6 and the metal elastic roll 7 is (Th-20 ° C ) S Tr ' ( Th + 20 ° C for the heat distortion temperature (Th ) of the thermoplastic resin. Preferably, it is preferably (Th-15 ° C) STrS (Th + 10 ° C), more preferably (Th - 10 ° C) STrS (Th + 5 ° C). On the other hand, if the surface temperature (Tr) is lower than (Th-2(TC), the shrinkage rate S 2 tends to be small. In addition, the surface temperature (Tr ) is higher than (Th + 2 0 ° C). In the case where the shrinkage rate si is increased, the in-plane retardation 値 tends to be large. Further, the appearance of the peeling trace remaining from the roll tends to be impaired in the resin sheet. -27- 201022746 Also, the laminate in the present invention The multi-layer resin sheet of the dissimilar material is also the object of the present invention, and the heat distortion temperature (Th) at this time is based on the resin having the highest heat distortion temperature (Th) in the shrinkage ratios SI and S2, and the surface temperature (Tr). The resin having the highest heat distortion temperature (Th) is also used as a reference. The heat distortion temperature (Th) is not particularly limited, but is generally about 60 to 2 ° C. The heat distortion temperature (Th) is ASTM D- 648 is the temperature measured. The light guide plate of the present invention formed by extruding the resin sheet thus obtained is not easily thermally deformed even when Q is used for a thinner large-screen backlight, so that it can be used for a liquid crystal display. For use as a satellite navigation system, carrying intelligence ends, industry It is used for backlighting of mechanical control panels, portable game consoles, notebook computers, LCD screens, LCD TVs, etc., especially for thin backlights used for carrying information terminals, portable game consoles, notebook computers, etc. When the extruded resin sheet is used as a light guide plate, for example, printing and surface cutting can be performed, and the cutting can be performed to a predetermined shape or size, and edge © honing can be performed. Thus, a light source such as an LED or a cold cathode tube can be assembled. Further, it is combined with a reflective film, a tantalum film, and a diffusing film to form a backlight unit. The light guide plate of the present invention is characterized in that it is less susceptible to thermal deformation, and light leakage or brightness reduction of the thermally deformed backlight is less. The embodiment of the present invention is shown, but the present invention is not limited thereto. The configuration of the "extrusion device" is as follows. -28- 201022746 Extruder 1: a spiral diameter of 65 mm, one axis, with an opening (Toshiba) Machine (unit)) Extruder 2: Spiral diameter 45 mm, one shaft, with opening (made by the shipbuilding system) Supply bushing: 2 types of 3 layers and 2 types of 2 layers (Day Shipbuilding (stock) system Mold 3: T mould, flange width 1400mm, flange spacing lmm (φ Hitachi Shipbuilding Co., Ltd.) Roll: Horizontal type, face length 1 400mm, diameter 300mm φ chill roll 2 The crucibles 1 and 2 and the mold 3 are arranged such that the supply sleeve is placed at a predetermined position as shown in Fig. 1. Then, the one of the two cooling rolls closest to the extruders 1, 2 is taken as 1 In the number of rolls, the take-up rolls are used as the No. 2 rolls, and the rolls are formed as follows. _ <Light configuration 1 > The configuration shown in Fig. 2 is used as the roll configuration 1. Specifically, the No. 1 roll and the No. 2 roll are as follows (No. 1 roller) The metal film 9 is placed so as to cover the outer peripheral surface of the shaft roller 8, and a metal elastic roller 7 of a fluid 1 is sealed between the shaft roller 8 and the metal film 9 as a No. 1 roller. The shaft roller 8, the metal film 9 and the fluid 10 are as follows. Shaft roller 8: Made of stainless steel -29- 201022746 Film 9: Mirrored metal sleeve made of stainless steel having a thickness of 2 mm Fluid 10: This is oil, and by controlling the temperature, the temperature of the metal elastic roller 7 can be controlled. More specifically, the oil can be heated and cooled by the on-off control of the temperature controller, and the temperature can be controlled to circulate between the shaft roller 8 and the metal film 9. (No. 2 roll) A stainless steel spiral roll having a surface state as a mirror surface was used as the high-rigidity metal roll 6, and this was used as the No. 2 roll. Further, the contact length of the metal elastic roller 7 and the metal roller 6 in contact with the molten thermoplastic resin 4 was 5 mm. <Roll configuration 2> Both the No. 1 roll and the No. 2 roll were used as a high-rigidity metal roll (a stainless steel spiral roll having a mirror surface). The thermoplastic resins used in the following examples and comparative examples are as follows. © Resin 1: Copolymer of methyl methacrylate / methyl acrylate = 94 / 6 (by weight). The heat distortion temperature (Th) is 10 CTC. The ultraviolet absorbing agent contains 2 parts by weight of 2-(p-methoxybenzylidene)malonate dimethyl hydrazine. Resin 2: A polymer of only aromatic polycarbonate ("Iupilon S2000" manufactured by Mitsubishi Industrial Plastics Co., Ltd.). The heat distortion temperature (Th) is 14 (TC ° resin 3: methyl methacrylate / methyl acrylate = 98 / 2 (weight ratio -30 - 201022746) copolymer. The heat distortion temperature (Th) is i 〇〇 ° c. As a UV absorber, 2-(2-hydroxy·5·methylphenyl)-2H-benzotriazolium.〇1 parts by weight. Resin 4: Methyl methacrylate/styrene=60/40 Copolymer (weight ratio) (Planeloy ΚΜ6Α, manufactured by A&L, Japan). The heat distortion temperature (Th) is 10 ° C. Resin 5: styrene-only polymer (Toyo Styrene) Toyo styrol HRM-40). The heat distortion temperature (Th) is 100 C. Resin 6: 70% by weight of copolymer of methyl methacrylate/methyl acrylate = 9 6/4 (weight ratio) The acrylic resin composition of 30% by weight of the acrylic multilayer elastomer obtained in the following Reference Examples has a heat distortion temperature (Th) of 10 (TC. The ultraviolet absorber contains 2,2'-extended methyl bis (4- (1,1,3,3-tetramethylbutyl)-6-((2H-benzotriazol-2-yl)phenol) 〇·1 part by weight. Resin 7: contains ethylenic acid having an alicyclic structure Polymerization of unsaturated monomer unit φ The product (manufactured by Nippon Co., Ltd., "ΖΕΟΝ OR1020R"). The heat distortion temperature (Th) is 10 (TC), and the content of the ultraviolet absorbing material is 100 parts by weight of the thermoplastic resin. [Reference Example] (Rubber) (Production of the granules) According to the method described in the examples of Japanese Patent Publication No. 55-27576, an acrylic multilayer elastic body composed of a three-layer structure is produced. Specifically, the first-31 - 201022746 glass having an internal volume of 5 L is produced. In a reaction vessel, 17 g of ion-exchanged water, 7 g of sodium carbonate, and 0.3 g of sodium persulfate were placed, and the mixture was stirred under a nitrogen stream, and then charged with PELEX OT-P (made by Kao) 4.46 g, ion. After exchanged 150 g of water, 50 g of methyl methacrylate, and 3 g of allyl methacrylate, the temperature was raised to 751 and stirring was continued for 150 minutes. 6.8 g of butyl acrylate, 162 g of styrene, and allyl group were further continued. A mixture of 17 g of acrylate was mixed with 0.85 g of sodium persulfate, 7.4 g of PELEX OT-P and 50 g of ion-exchanged water at a further inlet for a further 90 minutes, and polymerization was continued for another 90 minutes. After the end of the polymerization, the solution was dissolved. Acrylate 3 2 6g, ethyl A mixture of 14 g of acrylate and 30 g of ion-exchanged water of 0.34 g of sodium persulfate was added through another port for 30 minutes. After the end of the addition, the mixture was further kept for 60 minutes to complete the polymerization. The obtained latex was poured into a 0.5% aqueous solution of aluminum chloride. And agglomerate the polymer. This was washed with warm water for 5 times and dried to obtain an acrylic multilayer elastomer. [Examples 1 to 6, 8 and Comparative Examples 1 to 4] <Production of Extrusion Resin Sheet> The resin of the type shown in Table 1 was melt-kneaded by an extruder 1 to supply a sleeve and a mold. The order of 3 is supplied. On the other hand, the molten thermoplastic resin 4 extruded from the mold 3 was formed by laminating the No. 1 roll and the No. 2 roll which were formed by the rolls shown in Table 1, and the extruded resin sheets having the thickness shown in Table 1 were obtained. Further, "No. 1 roll surface temperature" and "No. 2 roll surface temperature" in Table 1 are the actual measurement of the surface temperature of the roll. -32-201022746 [Example 7] As the resin layer A, the resin of the type shown in Table 1 was melt-kneaded by the extruder 1 and supplied to a supply sleeve. On the other hand, as the resin layer B, the resin of the type shown in Table 1 was melt-kneaded by the extruder 2 and supplied to the supply jacket. The resin layer A supplied to the supply sleeve by the extruder 1 serves as a main layer, and the resin layer B supplied from the extruder 2 to the supply sleeve is formed under the surface layer (φ sheet surface/upper side) and is subjected to co-extrusion molding. On the other hand, the molten thermoplastic resin 4 extruded from the mold 3 was held by the No. 1 roll and the No. 2 roll which were formed by the rolls shown in Table 1, and the film layer B was bonded to the No. 2 roll, and it was obtained from Table 1. The two-layer structure of the thickness is used to extrude the resin sheet. Further, "thickness" in the extruders 1, 2 in Table 1 indicates the respective thicknesses of the resin layers A and B. Further, the "total thickness" in Table 1 indicates the total thickness of the obtained extruded resin sheet. [Example 9 and Comparative Example 5] As the resin layer A, the resin of the type shown in Table 1 was melt-kneaded by the extruder 1 and supplied to a supply sleeve. On the other hand, as the resin layer B, the resin of the type shown in Table 1 was melt-kneaded by the extruder 2 and supplied to the supply jacket. The resin layer A supplied from the extruder 1 to the supply sleeve serves as an intermediate layer, and the resin layer B supplied from the outlet 2 to the supply sleeve is pressed and formed into two layers to perform co-extrusion molding. On the other hand, the molten thermoplastic resin 4 extruded from the mold 3 was formed by laminating the No. 1 roll and the No. 2 roll formed by the rolls shown in Table-33-201022746, and the thickness of the layer shown in Table 1 was obtained. The structure is made of a resin plate. <Evaluation> For each of the obtained extruded resin sheets (Examples 1 to 9 and Comparative Examples 1 to 5), evaluation of shrinkage ratio, measurement of in-plane retardation, and evaluation of backlight unit (hereinafter referred to as unit evaluation) were performed. ). The evaluation methods and test methods are shown below, and the results are shown together in Table 1. (Shrinkage ratio) The shrinkage ratios SI and S2 in the extrusion direction and the width direction were calculated in accordance with the method described above. Further, in the shrinkage ratio S1'S2 in Table 1, the result of + indicates shrinkage, and the result of - indicates expansion. (In-plane retardation 値) The extrusion plate was cut out to a square having a side length of 50 mm, and the measurement was performed using an in-plane retardation 値 using a micro-area complex refractometer ("KOBRA-CCO/X" manufactured by Oji Scientific Instruments Co., Ltd.). (Unit evaluation) First, the extrusion plate was cut out to a size of 10 cm x 20 cm, and the LED chips were arranged at intervals of 1 cm on the 10 cm side to obtain a backlight unit body. The LED was turned on at 24V, a reflective film was placed on the back of the extrusion plate, and two diffusion films were placed on the front to obtain a backlight unit. The backlight unit was placed in an oven at 80 °C. After 24 hours, the backlight sheet 201022746 was taken out to visually observe whether there was deformation by heating or whether the emitted light before and after heating was colored.

-35- 201022746 Unit evaluation shot light color heating after 揉 destroy i slightly yellow to destroy 1 slightly yellow to destroy i slightly yellow to destroy 璀揉壊 before heating 璀揉壊 slightly yellow loaded slightly yellow 揉 slightly yellow m destroy m 壊 destroy Deformation 璀m Destroy m 揉擗m 揉 1 1 In-plane stagnation 1 inch οο (Ν CN Π 230 j \〇V0 393 fN Ό CN m 卜 ΟΟ o 1 o 〇-1.9 'sD 1 ΓΟ 1 o inch · v 〇fN m So 〇\ <N oo rvi 00 r4 <-i O\ o Os «Ν inchίΝ 00 ν〇2 roller surface temperature P name o 1···^ ss Γ0 *—Η s 1 Roll surface temperature P 〇ΟΟ 〇\ 沄mm 00 Os On Os οο On 〇\ os 00 〇\ o (N ««Μ 〇Os On s Roller composition type»~·Η CN CNfN — CN *-<H (N <N 1 total thickness mm d Ό Ο u-ϊ (N <N 0.65 0.65 〇o \〇〇gout machine 2 thickness mm 1 1 1 1 1 1 1 1 1 • 1 0,05 : 1 0.07 /0.07 0.07/0.071 Λ P 1 1 1 1 1 1 1 1 1 1 O too 1 Resin layer 种类 Type ♦ 1 1 1 1 1 1 1 1 r"i 1 Ό i Thickness mm VC Ο Ο VJ d on < N Ν » »N 0.65 -1 0.65 0.45 inch 〇 0.46 -1 0.46 | P Ο Ο o VMM o 〇Ο o 〇ooo 〇oo ” J m resin layer A type <N CN inch inch lA \〇fN Example 1 Comparative Example 1 Example 2 Example 3 Example 4 Comparative Example 2 Example 5 Comparative Example 3 Example 6 Comparative Example 4 Example 7 Example 8 Example 9 1 Comparative Example 5 i

-36- 201022746 It is understood from Table 1 that the extruded resin sheets according to Examples 1 to 5 of the present invention have a shrinkage ratio S1 in the extrusion direction and a shrinkage ratio S2 in the width direction in the range of 〇 5% to 5%. Its shrinkage rate is small. In the unit evaluation, no deformation is known to occur. From the results, it was found that the light guide plates made of the extruded resin sheets of Examples 1 to 5 were not easily thermally deformed even when used in a large-screen backlight even when the thickness was thin. In particular, the light guide plate made of the extruded resin sheets of Examples 1, 2, and 4 to 9 had an in-plane retardation 値 of 200 nm or less, and no coloring of φ emitted light was observed. On the other hand, the shrinkage ratios S1 and S2 of the extruded resin sheets of Comparative Examples 1 to 3 and 5 were all outside the scope of the present invention, and the shrinkage ratio S2 of the extruded resin sheets of Comparative Example 4 was also outside the range of the present invention. In the unit evaluation, the deformation is seen. Further, the light guide plate made of the extruded resin sheets of Comparative Examples 2 and 3 exceeded the in-plane retardation 値 of 200 nm, and the color of the emitted light was observed. BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] is a schematic explanatory view showing a method of manufacturing an extruded resin sheet according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view showing a metal roll and an elastic roll according to an embodiment of the present invention. Fig. 3 is a cross-sectional explanatory view showing an elastic roller according to another embodiment of the present invention. [Explanation of main component symbols] 1, 2: Extruder-37- 201022746 3 : Mold 4: molten thermoplastic resin 5: cooling roller 6: metal light 7, 15: metal elastic roller 8, 16: shaft roller 9, 17 :Metal film 1 〇: Fluid 1 1 : Extruded resin plate

-38-

Claims (1)

201022746 VII. Patent application scope: 1. A kind of light guide plate, which is a light guide plate made of extruded tree boards with a thickness of 0.1~2.0mm, and the above extruded resin plate is placed in a thermal environment of 120 °C for 0.5 hours. The shrinkage ratio (%) in the extrusion direction of the extruded resin sheet and the shrinkage ratio S2 (%) in the width direction are both 0 to 5%. 2. The light guide plate of claim 1, wherein the in-plane retardation of the extruded die plate is 200 nm or less. Under the grease S1 tree -39"