KR101374416B1 - Light diffusion sheet - Google Patents

Abstract

An object of this invention is to provide the light-diffusion sheet excellent in dimensional stability, light resistance, light diffusivity, thermal stability, brightness, and recycling property. The present invention provides a multi-layered light diffusion sheet, in which a surface layer a and a double layer c each contain the following (A) component: styrene-based monomer units 20 to 100 mass% and (meth) acrylic acid ester monomer units 80 to 0 mass% To 100 parts by mass of the copolymer, 1 to 10 parts by mass of the unmelted compound having a refractive index difference of less than 0.005 and an average particle diameter of 5 to 15 µm, a hindered amine compound and 0.1 to 2 parts by mass of the styrene copolymer, and benzo A styrene resin composition comprising 0.1 to 2 parts by mass of a triazole compound, wherein the intermediate layer b contains (B) component: 90 to 99% by mass of the styrene monomer unit and 10 to 1% by mass of the (meth) acrylic acid monomer unit. Undissolved compound 1 to 1 having a refractive index difference of 0.05 to 0.15 and an average particle diameter of 2 to 10 µm with respect to 100 parts by mass of the styrenic copolymer to be included. It relates to a multilayer sheet containing a styrene resin composition containing 0.5 to 2.5 parts by mass of polyorganosiloxane crosslinked beads having 10 parts by mass or a particle diameter of 1 to 10 µm.

Multi-layered light diffusion sheet, styrene resin composition, styrene copolymer, undissolved compound, hindered amine compound, benzotriazole compound, surface layer, intermediate layer, double layer, crosslinked copolymer, crosslinked polymer

Description

Light Diffusion Sheet {LIGHT DIFFUSION SHEET}

The present invention relates to a multilayer sheet having excellent light diffusivity, dimensional stability, light resistance, thermal stability, brightness and recycling properties. In particular, it is related with the light-diffusion sheet used as a transmission type screen of screens, such as a projection television, and the light-diffusion plate of a liquid crystal television.

Screen lenses such as transmissive screens used in projection televisions project images onto them to display images. Since this screen lens is required for the viewer to be bright and have a wide viewing angle, the screen lens is generally a combination of lens molded bodies such as lenticular lenses and Fresnel lenses. Methacrylic resins excellent in transparency, light resistance, scratch resistance, molding processability, and the like are widely used for these lens molded bodies, and these molded bodies are generally molded by press molding, extrusion molding, cast molding, injection molding, or the like.

Since the methacryl resin used for such a screen lens has a high water absorption rate, the dimensional change of the molded article for the screen lens may occur, the screen may be bent or lifted, the optical properties may be impaired, or the screen lens may be dropped from the frame. Had. In addition, there has been a problem that deformation occurs when the temperature during transport of the screen lens or the use environment temperature increases.

Moreover, there was a problem that the screen lens and the light diffusion plate were thermally deformed by irradiating the light of the lamp for a long time.

In order to solve these problems, JP-A-5-341101 discloses a styrene-diene copolymer in a mixture of an aromatic vinyl monomer, a (meth) acrylic acid ester monomer and a polyfunctional unsaturated monomer to polymerize it. A method of obtaining a Fresnel lens is disclosed. However, this technique was insufficient to obtain a molded article for screen lenses having excellent light diffusing properties.

Moreover, since the absorption rate is high also about the methacryl resin used as a base material of the light-diffusion plate of a liquid crystal television, the dimension of the light-diffusion plate molded object arises, the light-diffusion plate arises, and the optical characteristic was impaired. . Moreover, when the light of an image or a lamp is irradiated for a long time, discoloration will arise by deterioration of resin used for a screen lens or a light-diffusion plate, and it has a problem that an image discolors.

DISCLOSURE OF THE INVENTION <

Problem to be solved by invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer sheet having excellent light diffusivity, dimensional stability, light resistance, thermal stability, brightness, and recycling properties, in particular, a multilayer sheet used as a light diffusing plate such as a molded article for a screen lens or a molded article for a light diffuser plate. .

MEANS FOR SOLVING THE PROBLEMS [

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, an intermediate layer of the resin composition containing the copolymer which has a styrene-based monomeric unit and a methacrylic acid monomeric unit as a main component, and a specific unmelted compound or polyorganosiloxane crosslinked bead is carried out. The multilayer sheet which makes a surface layer and two layers the resin composition containing the copolymer which has a styrene monomer unit and a (meth) acrylic acid ester monomer unit as a main component, a specific unmelting compound, and a specific light-resistant agent, The inventors have found that the light diffusing property, the dimensional stability, the light resistance, the thermal stability, the luminance and the recycling property are excellent, and the present invention has been reached.

That is, the present invention has the following points.

1. A light-diffusion sheet having a multilayer configuration, wherein the surface layer a and the second layer c include the following (A) component, and the intermediate layer b contains the (B) component.

(A) component: The refractive index difference with this styrene-type copolymer with respect to 100 mass parts of styrene-type copolymers containing 20-100 mass% of styrene-type monomeric units and 80-0 mass% of the (meth) acrylic acid ester-type monomeric unit A styrene resin composition comprising 1 to 10 parts by mass of an undissolved compound having an average particle diameter of 5 to 15 μm, 0.1 to 2 parts by mass of a hindered amine compound, and 0.1 to 2 parts by mass of a benzotriazole compound.

(B) component: The refractive index difference with respect to the styrene-based copolymer is 0.05 with respect to 100 parts by mass of the styrene-based copolymer containing 90 to 99 mass% of the styrene monomer unit and 10 to 1 mass% of the (meth) acrylic acid monomer unit. A styrene resin composition comprising 1 to 10 parts by mass of an unmelted compound having an average particle size of 2 to 10 µm and 0.5 to 2.5 parts by mass of a polyorganosiloxane crosslinked bead having an average particle diameter of 1 to 10 µm.

2. Surface layer a and double layer c contain said (A) component, The intermediate | middle layer b grind | pulverized the multilayer sheet of said 1, 0-40 mass%, 90-99 mass% of styrene-based monomeric units, and methacrylic acid It contains 1-10 mass parts of unmelted compounds with a refractive index difference of 0.05-0.15 and the average particle diameter of 2-10 micrometers with respect to 100 mass parts of styrene copolymers containing 10-1 mass% of monomeric units. The multilayer sheet containing 100-60 mass% of styrene-type resin compositions formed by this.

3. Multilayer sheet | seat of said 1 or 2 whose unmelted compound contained in (A) component is a crosslinked copolymer containing styrene and methyl methacrylate as a monomeric unit.

4. Multilayer sheet in any one of said 1-3 whose unmelted compound contained in (B) component is a crosslinked polymer containing methyl methacrylate as a monomeric unit.

5. The multilayer sheet according to any one of 1 to 4 above, wherein the hindered amine compound is bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate.

6. The multilayer according to any one of 1 to 5, wherein the benzotriazole compound is 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol Sheet.

7. In any one of 1 to 6 above, at least one of (A) component and (B) component contains 0.0005-0.5 mass part of benzoxazole type compounds with respect to 100 mass parts of styrene copolymers. The multilayer sheet described.

8. The multilayer sheet according to the above 7, wherein the benzoxazole compound is 2,5-thiophendiyl (5-t-butyl-1,3-benzoxazole).

9. Multilayer sheet in any one of said 1-8 which contains 0.1-3 mass parts of amine surfactant further with respect to 100 mass parts of styrene-type copolymers of (A) component.

10. The multilayer sheet according to 9 above, wherein the amine surfactant is N-hydroxyethyl-N- (2-hydroxyalkyl) amine.

11. 7-20 mass parts of polyetheresteramide block copolymers with a refractive index difference of 0.02 or less with respect to 100 mass parts of styrene-type copolymers of (A) component, anionic surfactant, and a non-amine nonionic. The multilayer sheet in any one of said 1-8 containing 2 mass parts or less of surfactant.

12. The multilayer sheet according to 11, wherein the polyetheresteramide block copolymer is a polyetheresteramide block copolymer containing the following (F-A), (F-B) and (F-C) as monomer units.

(F-A): aminocarboxylic acid or lactam of 6 or more carbon atoms, or a salt of diamine and dicarboxylic acid of 6 or more carbon atoms.

(F-B): at least one diol compound of formulas (1) to (3).

Wherein R1 is an ethylene oxide group, R2 is an ethylene oxide group or a propylene oxide group, X is a halogen, an alkyl group (C1-6) or a sulfonic acid group or a metal salt thereof, L is an integer of 0-4, m and n represents an integer of 16 or more.

Wherein R1 is an ethylene oxide group, R2 is an ethylene oxide group or a propylene oxide group, X is a halogen, an alkyl group (C1-6) or a sulfone group or a metal salt thereof, Y is an alkylene group (C1-6) , Alkylidene group (1 to 6 carbon atoms), cycloalkylidene group (7 to 17 carbon atoms), arylalkylidene group (7 to 17 carbon atoms), O, SO, SO ₂ , CO, S, CF ₂ , C (CF ₃ ) ₂ or NH, L represents an integer of 0 to 4, m and n represent an integer of 16 or more.

In formula, R <1> is an ethylene oxide group, R <2> is an ethylene oxide group or a propylene oxide group, m and n represent the integer of 16 or more.

(F-C): dicarboxylic acid having 4 to 20 carbon atoms.

13. Said 11 whose compounding ratio (mass ratio) of anionic surfactant and nonamine nonionic surfactant in (A) component is anionic surfactant / nonamine nonionic surfactant = 0.5 / 99.5-15 / 85. Or the multilayer sheet according to 12.

14. The multilayer sheet according to any one of 11 to 13 above, wherein the anionic surfactant in component (A) is an organic sulfonic acid metal salt having 10 to 14 carbon atoms, and the nonamine nonionic surfactant is glycerin fatty acid ester.

15. The multilayer sheet according to any one of 1 to 14 above, wherein each layer of the multilayer structure has a surface layer a and a two layer c of 0.005 to 0.5 mm, and an intermediate layer b of 1 to 7 mm.

16. The multilayer sheet according to any one of 1 to 15 above, obtained by simultaneously extruding and processing the surface layer a, the intermediate layer b, and the double layer c.

EFFECTS OF THE INVENTION [

The light diffusing sheet of the present invention can be suitably used for optical display applications because of its excellent light diffusivity, dimensional stability, light resistance, thermal stability, and luminance. In addition, since the recyclability is excellent, it is possible to improve the yield and thereby reduce the cost.

BEST MODE FOR CARRYING OUT THE INVENTION [

Hereinafter, the present invention will be described in detail.

As a styrene-type monomer used for this invention, styrene, (alpha) -methylstyrene, p-methylstyrene, p-t-butyl styrene, etc. are mentioned, for example, Preferably it is styrene.

As the (meth) acrylic acid ester monomer in the present invention, for example, methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2 -Ethylhexyl acrylate, octyl acrylate, etc. are mentioned. These may be used independently and may use 2 or more types together. Preferably, it is methyl methacrylate, ethyl acrylate or n-butyl acrylate or a mixture thereof.

The styrene copolymer in the component (A) used for the surface layer and the second layer of the present invention is 20 to 100% by mass of the styrene monomer unit, preferably 50 to 90% by mass, and 80 to 90 of the (meth) acrylic acid ester monomer unit. 0 mass%, Preferably it contains 50-10 mass%. When the styrene-based monomer unit is less than 20% by mass, the light diffusion sheet obtained may be bent by moisture absorption. When the styrene-based copolymer contains 50 to 90 mass% of the styrene monomer unit and 10 to 50 mass% of the (meth) acrylic acid ester monomer unit, the compatibility with the copolymer in the component (B) is improved. It is excellent in the recycling property of a light-diffusion sheet.

The styrene copolymer in the component (B) used in the intermediate layer of the present invention is 90 to 99 mass% of the styrene monomer unit, preferably 91 to 97 mass%, and 10 to 1 mass% of the methacrylic acid monomer unit, preferably Preferably 3 to 9 mass%. When the styrene-based monomer unit exceeds 99% by mass, the thermal stability of the light diffusion sheet obtained may be lowered, and when less than 90% by mass, deformation may be caused by moisture absorption.

Examples of the (meth) acrylic acid monomer in the present invention include methacrylic acid, acrylic acid and ethacrylic acid. Preferably methacrylic acid.

The styrene copolymer in (B) component used for the intermediate | middle layer of this invention may be copolymerized with the vinyl monomer copolymerizable with these other than a styrene monomer and a methacrylic acid monomer, and the quantity is a styrene monomer and (meth) 10 mass parts or less are preferable with respect to 100 mass parts of total amounts of an acrylic acid type monomer. As this copolymerizable vinylic monomer, For example, vinyl cyanide monomers, such as an acrylonitrile and methacrylonitrile; Unsaturated carboxylic acid monomers such as acrylic acid, maleic anhydride, maleic acid, itaconic acid and itaconic anhydride; Maleimide monomers, such as maleimide, N-methyl maleimide, and N-phenyl maleimide, etc. are mentioned. These may be used independently or may use 2 or more types together.

As for the unmelted compound in (A) component, the compound which has melting | fusing point or softening point of 200 degreeC or more, preferably 220-320 degreeC in 1 atmosphere of atmosphere is preferable. When melting | fusing point or a softening point are less than 200 degreeC, the said compound is easy to melt | melt at the time of melt-kneading of a styrene type copolymer, or at the time of sheeting of a styrene resin composition, and may not be able to maintain the outstanding optical characteristic. The difference in refractive index between the styrene copolymer and the unmelted compound in the component (A) is within 0.005, preferably within 0.003. When the refractive index difference exceeds 0.005, the total light transmittance and the light diffusivity decrease. Moreover, the average particle diameter of an unmelted compound is 1-15 micrometers, Preferably it is 5-14 micrometers. When the average particle diameter is less than 1 µm, the haze and the diffusion rate decrease, resulting in a decrease in the light diffusivity. When the average particle diameter exceeds 15 µm, the total light transmittance and the light diffusion rate decrease. In addition, the average particle diameter of an unmelted compound is a value obtained by measuring using a Coulter multisizer (made by Beckmen Coulter). The measurement is performed by a laser diffraction light scattering method, using water as a solvent, applying a 200 W output using a homogenizer for 1 minute to disperse the sample, and adjusting the concentration of PIDS (Polarization Intensity Differential Scattering) to 45 to 55%. The water was measured at a refractive index of 1.33, and the average value was calculated from the volume distribution.

The unmelted compound needs to contain 1-10 mass parts, preferably 2-9 mass parts with respect to 100 mass parts of styrene-type copolymers in (A) component. When the content of the unmelted compound is less than 1 part by mass, the haze and the diffusion rate decrease and the light diffusivity decreases. When the content of the unmelted compound exceeds 10 parts by mass, the total light transmittance and the light diffusivity tend to decrease. Although the unmelted compound in (A) component is not specifically limited, The crosslinked copolymer containing styrene and methyl methacrylate as a monomeric unit is preferable.

In the component (A), 0.1 to 2 parts by mass of the hindered amine compound, preferably 0.2 to 1.2 parts by mass and 0.1 to 2 parts by mass of the benzotriazole compound, preferably 0.2 to 1 part by mass based on 100 parts by mass of the styrene copolymer. It must contain 1.2 parts by mass.

When the hindered amine compound and the benzotriazole compound are each less than 0.1 part by mass, the light resistance is lowered. When the hindered amine compound and the benzotriazole compound are more than 2 parts by mass, the yellowness of the resulting light diffusion sheet tends to be stronger.

The hindered amine compound is, for example, a decane dibis bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester or bis ( 1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis (1 , 2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis (2,2,6 , 6-tetramethyl-4-piperidyl) sebacate and the like. These may be used independently, and may mix and use 2 or more types.

Further, the benzotriazole-based compound is a ultraviolet absorber, for example, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazol-2-yl) -4-6 -Bis (1-methyl-1-phenylethyl) phenol, 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl] -6- (t-butyl) phenol, 2,4 -Di-t-butyl-6- (5-chlorobenzotriazol-2-yl) phenol, 2- (2H-benzotriazol-2-yl) -4,6-di-t-pentylphenol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol and the like. These may be used independently, and may mix and use 2 or more types.

In the present invention, in the component (A), or in at least one of the component (A) or the component (B), a benzoxazole compound, which is a so-called fluorescent brightener, as a colorant is preferably 0.0005 to 100 parts by mass of the styrene copolymer. To 0.5 parts by mass, more preferably 0.0008 to 0.2 parts by mass. When content of a benzoxazole type compound is 0.0005 mass part or more, the yellowness of the sheet | seat obtained is reduced compared with less than 0.0005 mass part, and while the external appearance improves more, it exists in the tendency for the brightness of the multilayer sheet obtained to become high, and it is preferable. In 0.5 mass parts or less, since the light resistance of the multilayer sheet obtained improves compared with the case exceeding 0.5 mass parts, it is preferable.

As a benzoxazole type compound, it is 2, 5- thiophendiyl (5-t-butyl- 1, 3- benzoxazole, 2, 5- thiophendiyl (5-t-butyl- 1, 3- benzo group, for example). A mixture of 10% of azole and 90% of dicyclohexyl phthalate, 4,4'-bis (benzooxazol-2-yl) stilbene, etc. may be mentioned, and these may be used alone or in combination thereof.

In the case where the antistatic performance is to be imparted to the multilayer sheet of the present invention for dust prevention, it is preferable to contain 0.1 to 3 parts by mass of the amine-based surfactant with respect to 100 parts by mass of the styrene copolymer in the component (A). When the amine surfactant is 0.1 parts by mass or more, a sufficient antistatic effect can be obtained as compared with less than 0.1 parts by mass. When it exceeds 3 mass parts, the sheet | seat obtained may be discolored compared with the case of 3 mass parts or less.

Examples of the amine surfactant include alkyl diethanolamine, polyoxyethylene alkylamine, alkyl diethanolamide, polyoxyethylene alkylamide, N-hydroxyethyl-N- (2-hydroxyalkyl) amine, and the like. These can be mentioned, These can also be used independently and can also use 2 or more types together.

In the case of providing scratch resistance and antistatic performance to the multilayer sheet of the present invention, a polyetheresteramide block copolymer having a refractive index difference of 0.02 or less with a styrene copolymer in (A) component is 100 mass of a styrene copolymer. 7 to 20 parts by mass, preferably 8 to 17 parts by mass, anionic surfactant and non-amine nonionic surfactant, and the amount thereof is 2 parts by mass or less, preferably 0.5 to 1.5 parts by mass, desirable.

When the polyetheresteramide block copolymer is 7 parts by mass or more, it is preferable because the scratch resistance of the multilayer sheet obtained in comparison with the case of less than 7 parts by mass is further improved and a sufficient antistatic effect is obtained. When content of a polyether esteramide block copolymer is 20 mass parts or less, since the yellowness of the multilayer sheet obtained reduces compared with the case exceeding 20 mass parts, it is preferable. Moreover, when the refractive index difference is 0.02 or less, since light transmittance improves compared with the case where it exceeds 0.02, it is preferable.

The monomer (F-A) in the polyetheresteramide block copolymer is an aminocarboxylic acid or lactam having 6 or more carbon atoms, or a salt of diamine and dicarboxylic acid having 6 or more carbon atoms. Examples of the aminocarboxylic acid having 6 or more carbon atoms include ω-aminocaproic acid, ω-aminocaprylic acid, ω-aminoenanthic acid, and 1,2aminododecanoic acid, and examples thereof include lactams. Examples thereof include caprolactam, enanthlactam, and capryllactam. As a salt of a C6 or more diamine and a dicarboxylic acid, hexamethylenediamine adipate, hexamethylenediamine sebacate, hexamethylenediamine isophthalate, etc. are mentioned, for example. As the monomer (F-A), caprolactam, 1,2aminododecanoic acid or hexamethylenediamine-adipic acid salt is particularly preferable.

The monomer (F-B) in the polyetheresteramide block copolymer is a diol compound, represented by the formulas (1) to (3).

&Lt; Formula 1 >

(Wherein R1 is an ethylene oxide group, R2 is an ethylene oxide group or a propylene oxide group, X is a halogen, an alkyl group (C1-6) or a sulfonic acid group or a metal salt thereof, L is an integer of 0-4, m And n represents an integer of 16 or greater)

(2)

(Wherein R1 is an ethylene oxide group, R2 is an ethylene oxide group or a propylene oxide group, X is a halogen, an alkyl group (1 to 6 carbon atoms) or a sulfone group or a metal salt thereof, Y is an alkylene group (1 to 6 carbon atoms) ), Alkylidene groups (1 to 6 carbon atoms), cycloalkylidene groups (7 to 17 carbon atoms), arylalkylidene groups (7 to 17 carbon atoms), O, SO, SO ₂ , CO, S, CF ₂ , C ( CF ₃ ) ₂ or NH, L represents an integer of 0 to 4, m and n represent an integer of 16 or more)

(3)

(Wherein R1 is an ethylene oxide group, R2 is an ethylene oxide group or a propylene oxide group, m and n represent an integer of 16 or more)

As these diol compounds, For example, ethylene oxide and / or propionoxide adduct of bisphenol A, ethylene oxide and / or propylene of 2, 2-bis (4,4'-hydroxycyclohexyl) propane Oxide adducts, ethylene oxide and / or propylene oxide adducts of dimethylbisphenol A, ethylene oxide and / or propylene oxide adducts of tetramethylbisphenol A, 2,2-bis (4,4'-hydride Ethylene oxide and / or propylene oxide adducts of oxyphenyl-3,3'-sodium sulfonate) propane, ethylene oxide and / or propylene oxide adducts of bisphenol S, 4,4 '-(hydroxy) ratio Ethylene oxide and / or propylene oxide adducts of phenyl, ethylene oxide and / or propylene oxide adducts of bis (4-hydroxyphenyl) sulfide, ethylene oxide of bis (4-hydroxyphenyl) methane And / or ethyl of propyleneoxide adduct, bis (4-hydroxyphenyl) amine Oxide and / or propylene oxide adduct, ethylene oxide and / or propylene oxide adduct of bis (4-hydroxyphenyl) ether, ethylene jade of 1,1-bis (4-hydroxyphenyl) cyclohexane Seed and / or propylene oxide adducts, ethylene oxide and / or propylene oxide adducts of 1,4-dihydroxycyclohexane, ethylene oxide and / or propylene oxide adducts of hydroquinone, dihydroxy Ethylene oxide and / or propylene oxide adducts of naphthalene, or block copolymers thereof.

Preferred diol compounds of the monomer (FB) are ethylene oxide adducts of hydroquinone, ethylene oxide adducts of bisphenol A, ethylene oxide adducts of bisphenol S, and ethylene oxide adducts of dihydroxynaphthalene, Or the block polymer may be sufficient. Especially preferred are ethylene oxide adducts of bisphenol A.

As the dicarboxylic acid, the monomer (FC) in the polyetheresteramide block copolymer is preferably a dicarboxylic acid having 4 to 20 carbon atoms. For example, terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dica Aromatic dicarboxylic acids such as leric acid and naphthalene-2,7-dicarboxylic acid; Alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 1,2-cyclohexanedicarboxylic acid; And succinic acid, oxalic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, and the like. Especially preferably, it is adipic acid.

The ratio of the monomer units in the polyetheresteramide block copolymer of (FA), (FB) and (FC) is 25 to 85 parts by mass (FA), 15 to 70 parts by mass (FB), and (FC) The ratio of 5-60 mass parts is preferable.

In the polymerization method of the polyether ester amide block copolymer, for example, aminocarboxylic acid or lactam (FA) is reacted with dicarboxylic acid (FC), and both ends of the polyamide prepolymer having a carboxylic acid group are reacted. To this end, a method of reacting the (FB) diol compound under vacuum or the compounds of the above-mentioned (FA), (FB) and (FC) is introduced into a reaction tank, and reacted at a high temperature to give a polyamide at the dicarboxylic acid terminal. There is a method of producing a prepolymer and then proceeding the polymerization under atmospheric pressure or reduced pressure.

As mentioned above, (A) component contains anionic surfactant and a non-amine nonionic surfactant with respect to 100 mass parts of styrene-type copolymers, The quantity is 2 mass parts or less, Preferably it is 0.5-1.5 mass parts It is preferable. Including anionic surfactant and non-amine nonionic surfactant, when the quantity is 2 mass parts or less, since the yellow color tone of the multilayer sheet obtained is reduced compared with the case where it is more than 2 mass parts, it is preferable.

Examples of the anionic surfactants include organic sulfonic acid metal salts, and specific examples thereof include sodium alkyl sulfonate, lithium alkyl sulfonate, sodium alkylbenzene sulfonate and lithium alkylbenzene sulfonate. Among these, sodium alkylsulfonate is used preferably. More preferably, it is sodium alkylsulfonate of 10-14 carbon atoms. These may be used independently and may use 2 or more types together.

As a nonamine nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, and glycerin fatty acid ester are mentioned, for example. Especially, glycerin fatty acid ester is used preferably. These may be used independently and may use 2 or more types together.

In the case of using the above-mentioned anionic surfactant and non-amine nonionic surfactant together, anionic surfactant / non-amine nonionic surfactant is 0.5 / 99.5 to 15/85 (mass ratio), preferably 5/95 When used at a ratio of from 12/88 (mass ratio), excellent antistatic performance is obtained.

The unmelted compound used for the component (B) is preferably a compound having a melting point or a softening point at 200 占 폚 or higher, preferably at 220 to 320 占 폚 in an atmosphere of 1 atmosphere. If melting | fusing point and a softening point are less than 200 degreeC, an unmelted compound will be easy to melt at the time of melt-kneading with a styrene copolymer, or at the time of sheeting of a styrene resin composition, and may not be able to maintain the outstanding optical characteristic. The difference in refractive index between the styrene copolymer and the unmelted compound in the component (B) is 0.05 to 0.15, preferably 0.07 to 0.13. If the refractive index difference is less than 0.05, the turbidity and the diffusivity of the resulting light diffusing sheet decrease and the light diffusivity decreases, and if it exceeds 0.15, the total light transmittance and the light diffusivity decrease. Further, the average particle diameter of the unmelted compound is 2 to 10 m, preferably 3 to 9 m. If the average particle diameter of an unmelted compound is less than 2 micrometers, turbidity of the obtained light-diffusion sheet will become small and light diffusivity will fall, and when it exceeds 10 micrometers, a total light transmittance will fall. In addition, the average particle diameter of a unmelted compound is a value obtained by measuring using a calder multisizer (made by Beckman Coulder Corporation).

In addition, the unmelted compound needs to contain 1-10 mass parts, preferably 2-9 mass parts with respect to 100 mass parts of styrene-type copolymers in (B) component. When the content of the unmelted compound is less than 1 part by mass, the turbidity of the resulting light diffusion sheet decreases and the light diffusivity decreases. When the content of the unmelted compound exceeds 10 parts by mass, the total light transmittance decreases. Although it does not specifically limit as a unmelted compound in (B) component, The crosslinked copolymer which mainly uses methyl methacrylate is preferable.

Moreover, as an unmelted compound used for (B) component, 0.5-2.5 mass parts of polyorganosiloxane crosslinked beads, Preferably 0.8-2.2 mass part is contained with respect to 100 mass parts of styrene-type copolymers. When the content of the polyorganosiloxane crosslinked beads is less than 0.5 parts by mass, the turbidity and the diffusion rate decrease, and the light diffusivity decreases. When the content of the polyorganosiloxane crosslinked beads exceeds 2.5 parts by mass, the total light transmittance decreases.

Although there is no restriction | limiting in particular in the manufacturing method of the styrene-type copolymer in (A) component, and the styrene-type copolymer in (B) component, The bulk polymerization method, suspension polymerization method, solution polymerization method, and emulsion polymerization method can be employ | adopted preferably. .

There is no restriction | limiting in particular in the mixing method of each raw material of (A) component and (B) component, The method of mix | blending just after superposition | polymerization before superposition | polymerization of each styrene-type copolymer, and melt-mixing with the separated styrene-type copolymer The compounding method is mentioned.

After pelletizing each of the styrenic copolymers, there is no particular limitation on the mixing method even when melt mixing the unmelted compound or the polyorganosiloxane crosslinked beads, for example, a Henschel mixer, a tumbler mixer, or the like. After pre-mixing by the well-known mixing apparatus of, it can mix uniformly by melt-kneading using an extruder, such as a single screw extruder or a twin screw extruder.

In addition, a high concentration mixture containing a high concentration of an unmelted compound or polyorganosiloxane crosslinked beads in a styrene copolymer is prepared, and the high concentration mixture and the styrene copolymer are dry blended in preparation of the light diffusion sheet. It can also be used as a raw material which made content of an undissolved compound or polyorganosiloxane crosslinking bead become a defined density | concentration.

An additive can be mix | blended with the styrene type copolymer in (A) component and the styrene type copolymer in (B) component as needed. For example, a plasticizer, a lubricating agent, silicone oil, etc. can be mix | blended in order to improve fluidity | liquidity and mold release property. Moreover, in order to provide thermal stability further, a heat stabilizer can be mix | blended. In addition, you may mix | blend a coloring agent.

The light diffusing sheet of the present invention has a multilayer structure, and the thickness of each layer is preferably 0.005 to 0.5 mm, more preferably 0.03 to 0.2 mm, of the surface layer a and the second layer c containing the component (A), ( It is preferable that the intermediate | middle layer b containing component B) is 1-7 mm, and 1.2-2.5 mm is more preferable. When the surface layer a and the two layer c are less than 0.005 mm, the light diffusion sheet obtained may be discolored by light irradiation, and when it exceeds 0.5 mm, it may be deformed by moisture absorption. In addition, when the intermediate | middle layer b exceeds less than 1 mm and exceeds 7 mm, the outstanding optical characteristic may not be obtained.

The light diffusing sheet may be bonded to the sheet obtained by separately extruding the surface layer a, the intermediate layer b, and the second layer c by thermal fusion or the like, or may be simultaneously extruded using a T dyna multimanifold die using a feed block. . The latter method is economically advantageous and also advantageous in terms of being easy to prevent scratches, foreign matters, and the like on the sheet surface during bonding.

The light-diffusion sheet of this invention has recycling property, and the surface layer a and the two-layer c contain the said (A) component, and the intermediate | middle layer b grind | pulverized the multilayer sheet containing the said (B) component from 0 to the intermediate layer b. It can recycle to contain 40 mass%, Preferably 5-25 mass%. The remainder (100-60 mass%) of the intermediate | middle layer b contains the said (B) component. When the quantity of the pulverized object of the said multilayer sheet contained in the intermediate | middle layer b exceeds 40 mass%, the total light transmittance of the sheet obtained will fall. Moreover, even when the pulverized product of the said multilayer sheet is contained in the intermediate | middle layer b, it is preferable that the table layer a and the bilayer c in the multilayer sheet of this invention contain the said (A) component.

Hereinafter, although an Example demonstrates this invention concretely, this invention is limited to these Examples and is not interpreted.

Method for producing styrene copolymer (A)

The tank used for manufacture is comprised by connecting the 1st complete mixing tank of about 5L by volume and the 2nd complete mixing tank of about 15L in series, and also connecting the 1st devolatilization tank and 2nd devolatilization tank which attached the preheater in series. It was. 15 mass parts of ethylbenzene, 0.01 mass part of t-butylperoxy isopropyl monocarbonate, and 2, 4- diphenyl with respect to 100 mass parts of monomer solutions comprised from 10 mass% of styrene and 90 mass% of methyl methacrylates 0.2 mass part of -4-methyl-1- pentene were mixed and it was set as the raw material solution. This raw material solution was supplied to the 1st complete mixing tank controlled at 135 degreeC at 6.0 kg every hour. The conversion at the outlet of the first complete mixing tank was 28 mass%. Next, it extracted continuously from the 1st complete mixing tank, and supplied to the 2nd complete mixing tank controlled at 135 degreeC. The conversion at the second complete mixing tank outlet was 63%. Next, it extracted continuously from the 2nd complete mixing tank, it heated in the preheater, and introduce | transduced into the 1st devolatilization tank controlled to 67 kPa and 160 degreeC. Furthermore, it extracted continuously from a 1st devolatilization tank, it heated up with a preheater, it introduce | transduced into the 2nd devolatilization tank controlled by 1.3 kPa, 230 degreeC, and the monomer was removed. The pellet-shaped styrene copolymer (A-1) was obtained by extruding this to strand shape.

A styrene copolymer (A-2) was obtained in the same manner as in (A-1) except that a monomer solution composed of 40% by mass of styrene and 60% by mass of methyl methacrylate was used.

A styrene copolymer (A-3) was obtained in the same manner as in (A-1) except that a monomer solution composed of 80% by mass of styrene and 20% by mass of methyl methacrylate was used.

A styrene copolymer (A-4) was obtained in the same manner as in (A-1) except that a monomer solution composed of 95% by mass of styrene and 5% by mass of methyl methacrylate was used.

Except using the monomer solution comprised from 100 mass% of styrene, it carried out similarly to (A-1), and obtained the styrene-type copolymer (A-5).

Preparation of Styrene Copolymer (B)

The tank used for manufacture is comprised by connecting the 1st complete mixing tank of about 5L by volume and the 2nd complete mixing tank of about 15L in series, and also connecting the 1st devolatilization tank and 2nd devolatilization tank which attached the preheater in series. It was. 15 parts by mass of ethylbenzene and 15 parts by mass of t-butylperoxyiso to 100 parts by mass of a monomer solution composed of 85% by mass of styrene containing 0.1 ppm of 4-t-butylcatechol and 15% by mass of methacrylic acid (hereinafter referred to as MAA) 0.01 parts by mass of propyl monocarbonate and 0.2 parts by mass of 2,4-diphenyl-4-methyl-1-pentene were mixed to obtain a raw material solution. This raw material solution was supplied to the 1st complete mixing tank controlled at 135 degreeC at 6.0 kg every hour. The conversion at the outlet of the first complete mixing tank was 28 mass%. Next, it extracted continuously from the 1st complete mixing tank, and supplied to the 2nd complete mixing tank controlled at 135 degreeC. The conversion at the outlet of the second complete mixing tank was 63 mass%. Next, it extracted continuously from the 2nd complete mixing tank, it heated in the preheater, and introduce | transduced into the 1st devolatilization tank controlled to 67 kPa and 160 degreeC. Furthermore, it extracted continuously from a 1st devolatilization tank, it heated up with a preheater, it introduce | transduced into the 2nd devolatilization tank controlled by 1.3 kPa, 230 degreeC, and the monomer was removed. The pellet-shaped styrene copolymer (B-1) was obtained by extruding and cutting | disconnecting this to strand shape.

A styrene copolymer (B-2) was obtained in the same manner as in (B-1) except that a monomer solution composed of 92% by mass of styrene and 8% by mass of methacrylic acid was used.

A styrene copolymer (B-3) was obtained in the same manner as in (B-1) except that a monomer solution composed of 96% by mass of styrene and 4% by mass of methacrylic acid was used.

A styrene copolymer (B-4) was obtained in the same manner as in (B-1) except that a monomer solution composed of 99.5% by mass of styrene and 0.5% by mass of methacrylic acid was used.

Polyorganosiloxane Crosslinked Bead (C)

As the unmelted compound, polyorganosiloxane cross-linked beads are tospal 120 (average particle diameter 2 µm, refractive index 1.420) (C-1), tospal 2000B (average particle diameter 6 µm, refractive index 1.420 ) (C-2) and Tospal 3120 (average particle diameter 12 탆, refractive index 1.420) (C-3) were used.

Method for producing MMA-nBA copolymerized crosslinked beads (D) as undissolved compounds

20 parts by mass of methyl methacrylate, 80 parts by mass of n-butyl acrylate, 5 parts by mass of divinylbenzene as a crosslinking agent, 0.2 parts by mass of benzoyl peroxide as a polymerization initiator, and sodium dodecylbenzenesulfonate as a suspension stabilizer in an autoclave with agitator. Mass part, 0.5 mass part of tricalcium phosphates, and 200 mass parts of pure waters were thrown in, and it superposed | polymerized at the temperature of 95 degreeC for 6 hours, and the temperature of 130 degreeC for 2 hours. After the reaction was completed, washing, dehydration, and drying were performed to obtain crosslinked beads (D). The average particle diameter of the crosslinked bead (D) of the unmelted compound was 4 m, and the refractive index was 1.460.

Process for producing styrene crosslinked beads (E) as undissolved compounds

100 parts by mass of styrene, 5 parts by mass of divinylbenzene as a crosslinking agent, 0.2 parts by mass of benzoyl peroxide as a polymerization initiator, 0.001 parts by mass of sodium dodecylbenzenesulfonate as a suspension stabilizer, and 0.5 parts by mass of tricalcium phosphate as pure water 200 mass parts was prepared, and it superposed | polymerized at the temperature of 95 degreeC for 6 hours, and the temperature of 130 degreeC for 2 hours. After the reaction was completed, washing, dehydration, and drying were performed to obtain a crosslinked bead (E). The average particle diameter of (E) was 8 micrometers, and the refractive index was 1.593.

Process for preparing styrene-MMA crosslinked beads (F) as undissolved compounds

40 parts by mass of styrene, 60 parts by mass of methyl methacrylate, 5 parts by mass of divinylbenzene as a crosslinking agent, 0.2 parts by mass of benzoyl peroxide as a polymerization initiator, and 0.001 parts by mass of sodium dodecylbenzenesulfonate as a suspension stabilizer in an autoclave with a stirrer 0.5 mass part of tricalcium phosphate and 200 mass parts of pure waters were thrown in, and it superposed | polymerized at the temperature of 95 degreeC for 6 hours, and the temperature of 130 degreeC for 2 hours. After the reaction was completed, washing, dehydration, and drying were performed to obtain crosslinked beads (F-1). The average particle diameter of (F-1) was 8 micrometers, and the refractive index was 1.535.

Except for using 1.0 part of 3rd calcium phosphates, the crosslinked beads (F-2) of 3 micrometers of average particle diameters and a refractive index of 1.535 were obtained by the manufacturing method similar to (F-1).

A crosslinked bead (F-3) having an average particle diameter of 13 µm and a refractive index of 1.535 was obtained by the same production method as in (F-1) except that 0.2 part of the third calcium phosphate was used.

Except for using 0.1 part of tricalcium phosphate, the crosslinked bead (F-4) of 18 micrometers of average particle diameters and a refractive index of 1.535 was obtained by the manufacturing method similar to (F-1).

Except for using 10 parts by mass of styrene and 90 parts by mass of methyl methacrylate, crosslinked beads (F-5) having an average particle diameter of 8 µm and a refractive index of 1.505 were obtained by the same production method as in (F-1).

A crosslinked bead (F-6) having an average particle diameter of 8 µm and a refractive index of 1.572 was obtained by the same production method as in (F-1) except that 80 parts by mass of styrene and 20 parts by mass of methyl methacrylate were used.

Further, 80 parts by mass of styrene and 20 parts by mass of methyl methacrylate, 5 parts by mass of divinylbenzene as a crosslinking agent, 0.2 parts by mass of benzoyl peroxide as a polymerization initiator, and 0.001 parts by mass of sodium dodecylbenzenesulfonate as a suspension stabilizer were added to the autoclave with agitator. And 0.5 parts by mass of tricalcium phosphate and 200 parts by mass of pure water were polymerized at a temperature of 95 ° C. for 6 hours and at a temperature of 130 ° C. for 2 hours. After the reaction was completed, washing, dehydration, and drying were performed to obtain crosslinked beads (F-7). The average particle diameter of (F-7) was 8 micrometers, and the refractive index was 1.575.

Except using 1.0 part of tricalcium phosphates, the crosslinked beads (F-8) of 3 micrometers of average particle diameters and 1.575 of refractive index were obtained by the manufacturing method similar to (F-7).

A crosslinked bead (F-9) having an average particle diameter of 13 µm and a refractive index of 1.575 was obtained by the same production method as in (F-7) except that 0.2 part of the third calcium phosphate was used.

A crosslinked bead (F-10) having an average particle diameter of 18 µm and a refractive index of 1.575 was obtained by the same production method as in (F-7) except that 0.1 part of the third calcium phosphate was used.

Method for producing PMMA crosslinked beads (G) as an unmelted compound

100 mass parts of methyl methacrylate, 5 mass parts of divinylbenzene as a crosslinking agent, 0.2 mass part of benzoyl peroxide as a polymerization initiator, 0.001 mass part of sodium dodecylbenzene sulfonates as a suspension stabilizer, and 0.5 mass of tricalcium phosphates in the autoclave with a stirrer Subsequently, 200 parts by mass of pure water was added, and polymerization was carried out at a temperature of 95 ° C. for 6 hours and at a temperature of 130 ° C. for 2 hours. After the reaction was completed, washing, dehydration, and drying were performed to obtain crosslinked beads (G-1). The average particle diameter of (G-1) was 8 µm and the refractive index was 1.494.

Except using 1.5 parts of tricalcium phosphates, the crosslinked beads (G-2) of 1 micrometer of average particle diameters and 1.494 refractive index were obtained by the manufacturing method similar to (G-1).

In addition, crosslinked beads (G-3) having an average particle diameter of 3 µm and a refractive index of 1.494 were obtained by the same production method as in (G-1) except that 1.0 part of the third calcium phosphate was used.

In addition, crosslinked beads (G-4) having an average particle diameter of 13 µm and a refractive index of 1.494 were obtained by the same production method as in (G-1) except that 0.2 part of the third calcium phosphate was used.

Colorant (H)

Fluorescent whitening agent 2,5-thiophendiyl (5-t-butyl-1,3-benzoxazole) as a coloring agent (Ubitex OB by Ciba Specialty Chemicals) (H-1), and an anthraquinone type which is a resin coloring agent An induction product (Dia Resin BLUE J manufactured by Mitsubishi Chemical Corporation) (H-2) was used.

As the amine surfactant, N-hydroxyethyl-N- (2-hydroxyalkyl) amine (Daspa 125B manufactured by Miyoshi Yushi Co., Ltd.) was used as (I).

Preparation of Polyetheresteramide Block Copolymer (J)

Polyetheresteramide (J-1) was obtained from 55 mass parts of caprolactam, 30 mass parts of ethylene oxide adducts of bisphenol A, and 15 mass parts of adipic acid. The refractive index of this polyetheresteramide was 1.530. Furthermore, polyether esteramide (J-2) was obtained from 40 mass parts of caprolactam, 45 mass parts of ethylene oxide adducts of bisphenol A, and 15 mass parts of adipic acid. The refractive index of this polyetheresteramide was 1.490.

Anionic Surfactants and / or Nonamine Nonionic Surfactants (K)

Sodium dodecyl sulfonate (K-1) was used as the anionic surfactant, and glycerin stearate diester (K-2) was used as the nonamine surfactant.

As styrene-based copolymers (A-1) to (A-3), (A-5), (B-1) to (B-4), crosslinked beads C-2, D, E, ( F-1) to (F-6), (G-1) to (G-4), bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate as hindered amine compounds , 2- (2H-benzotriazol-2-yl) -4,6-di-t-pentylphenol as a benzotriazole compound, (H-1) to (H-2) as a colorant, as an amine surfactant N-hydroxyethyl-N- (2-hydroxyalkyl) amine (I), (J-1) and (J-2) as polyetheresteramide block copolymers, sodium dodecyl sulfonate as anionic surfactant ( K-1) and glycerin stearic acid diester (K-2) were mixed at the compounding ratio shown to Table 1-3 to 1-5 as a non-amine nonionic surfactant. The resulting mixture was kneaded with a 40 mm diameter single screw extruder at a temperature of 240 ° C. and a screw rotation speed of 100 rpm, pelletized, and the styrene resin compositions 1-1 to 1- shown in Tables 1-2 to 1-5. 49 pellets were obtained.

Examples 1-1 to 1-25, Comparative Examples 1-1 to 1-28

Using the styrene resin composition 1-1 to 1-49, the light-diffusion sheet of the 3-layered constitution of the multilayered constitution shown in Tables 1-6 to 1-11 was produced with the T-die type | mold multilayer extruder which has a feed block. The multi-layer extruder also includes one single screw extruder of a 65 mmφ full-flight screw for the intermediate layer and one single screw extruder of a full-flight screw of 30 mmφ for the front and back layers, and each molten resin is multi-layered into the feed block. Was used. Each cylinder temperature of sheeting was operated and shape | molded at 230 degreeC.

The optical properties, light resistance, absorption deflection, thermal stability, antistatic property and scratch resistance of the obtained light diffusion sheet were evaluated, and the data are shown in Tables 1-6 to 1-11.

In addition, (A-1) to (A-3), (A-5), (B-1) to (B-4) as styrene copolymers, and crosslinked beads (C-1) to ( C-3), E, (F-1) to (F-6), G-1, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate as a hindered amine compound , 2- (2H-benzotriazol-2-yl) -4,6-di-t-pentylphenol as a benzotriazole compound, (H-1) to (H-2) as a colorant, as an amine surfactant N-hydroxyethyl-N- (2-hydroxyalkyl) amine (I), (J-1) to (J-2) as a polyetheresteramide block copolymer, sodium dodecyl sulfonate as anionic surfactant ( K-1) and glycerin stearic acid diester (K-2) were mixed at the compounding ratio shown to Table 2-3 to 2-5 as a non-amine nonionic surfactant. The resulting mixture was kneaded with a 40 mm diameter single screw extruder at a temperature of 240 ° C. and a screw rotation speed of 100 rpm to pelletize the styrene resin compositions 2-1 to 2-43 shown in Tables 2-3 to 2-5. Pellets were obtained.

Examples 2-1 to 2-21, Comparative Examples 2-1 to 2-26

Using the styrene-based resin compositions 2-1 to 2-43, a multi-layered light diffusing sheet having a multi-layer configuration shown in Tables 2-6 to 2-10 was produced by a T-die multi-layer extruder having a feed block. In addition, the multi-layer extruder includes one single screw extruder of a 65 mmφ full-flight screw for the intermediate layer, and one single screw extruder of a 30 mmφ full-flight screw for the front and back layers, and each molten resin was multi-layered into the feed block. An extruder was used. Each cylinder temperature of sheeting was operated and shape | molded at 230 degreeC.

The optical properties, light resistance, absorption deflection, thermal stability, antistatic property and scratch resistance of the obtained light diffusion sheet were evaluated, and the data are shown in Tables 2-6 to 2-10.

Moreover, as a styrene-type copolymer, (A-2)-(A-4), (B-1)-(B-4) and a crosslinking bead C-2, D, (F-7)-(as an unmelted compound F-10), (G-1) to (G-4), 2 as a bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate benzotriazole compound as a hindered amine compound -(2H-benzotriazol-2-yl) -4,6-di-t-pentylphenol, (H-1) to (H-2) as colorant, N-hydroxyethyl-N as amine surfactant -(2-hydroxyalkyl) amine (I) was mixed at the compounding ratios shown in Tables 3-3 and 3-4. The obtained mixture was kneaded with a 40 mm diameter single screw extruder at a temperature of 240 ° C. and a screw rotation speed of 100 rpm, pelletized, and the styrene resin compositions 3-1 to 3-32 shown in Tables 3-3 and 3-4. Pellets were obtained.

Examples 3-1 to 3-13, Comparative Examples 3-1 to 3-25

The light-diffusion sheets 3-1 to 3-38 of the three-layer configuration shown in Tables 3-5 to 3-12 by T-die multi-layer extruders having a feed block using styrene resin compositions 3-1 to 3-32. Was prepared. In addition, the multi-layer extruder includes one single screw extruder of a 65 mmφ full-flight screw for the intermediate layer, and one single screw extruder of a 30 mmφ full-flight screw for the front and back layers, and each molten resin was multi-layered into the feed block. An extruder was used. Each cylinder temperature of sheeting was operated and shape | molded at 230 degreeC.

In addition, 2-30 mass% of what grind | pulverized the obtained light-diffusion sheets 3-1 to 3-38 was added to the styrene resin composition used for the intermediate | middle layer of a sheet, and similarly, the light-diffusion sheet 3 of a 3-layered constitution is again carried out by the multilayer extruder. -1 'to 3-38' were prepared.

Optical characteristics, light resistance, absorption deflection, thermal stability, antistatic property, and recycleability of the obtained light diffusion sheet were evaluated, and the data are shown in Tables 3-5 to 3-12.

When the b value indicating turbidity of 99% or more, the total light transmittance of 65% or more, the diffusivity of 17% or more, and the yellowness is less than 1, the luminance is 3500 cm / m 2 or more, and the light resistance is judged to be good optical properties when the color difference ΔE value is less than 1 can do. In addition, in order to express excellent dimensional stability, it is necessary to have an absorption deflection of less than 1 mm, to express excellent thermal stability, to exhibit heat distortion of less than 1 mm, and to express excellent antistatic property, and to have a surface resistivity of 10 ¹² Ω or less.

[Table 1-1]

[Table 1-2]

[Table 1-3]

[Table 1-4]

[Table 1-5]

[Table 1-6]

[Table 1-7]

[Table 1-8]

[Table 1-9]

[Table 1-10]

[Table 1-11]

[Table 2-3]

[Table 2-4]

[Table 2-5]

[Table 2-6]

[Table 2-7]

Table 2-8

Table 2-9

Table 2-10

[Table 3-3]

Table 3-4

[Table 3-5]

[Table 3-6]

[Table 3-7]

Table 3-8

Table 3-9

Table 3-10

Table 3-11

Table 3-12

Each measuring method of the obtained light-diffusion sheet is as follows.

(1) Transmittance and turbidity: It measured using the HAZE meter (NDH-2000) by the Nippon Denshoku Kogyo Co., Ltd. according to ASTMD-1003.

(2) was available from Nippon Den syokku and using a goniophotometric (GC5000L) Preparation of the teacher, measuring the acceptance angle 0 ° of the light transmittance I _0, I ₇₀ can light transmission of the wide-angle 70 °, and calculating from the following equation.

Diffusion Rate (%) = (I ₇₀ / I ₀ ) × 100

(3) Light resistance: Color difference (DELTA) E after irradiating the light of wavelength of UVB-313 for 400 hours using the Atlas UV2000 by Toyo Seiki Seisakusho Co., Ltd. was measured.

(4) Dimensional stability (absorption deflection): The light diffusing sheet cut to a size of 180 mm x 180 mm was left to stand for 7 days in an atmosphere of 50 ° C and 80% humidity, and the deformation amount of the four corners before and after standing with a vernier caliper. It measured, and made the average value the value of absorption deflection, and made this value the measure of dimensional stability.

(5) Yellowness, color difference: L, a, b were measured using the Nippon Denshoku company color difference meter (Σ-80), and b value was shown as a measure of yellowness. In addition, the color difference (DELTA) E of light resistance evaluation was calculated | required by the following formula.

ΔE = ((L-L ') ² + (a-a') ² + (b-b ') ² ) ^1/2

However, L, a, and b are colors before light resistance evaluation, and L ', a', and b 'are colors after light resistance evaluation (after 400 Hr irradiation).

(6) Heating deformation: The light diffusion sheet cut | disconnected to the size of 300 mm x 300 mm is left to stand in the atmosphere of 80 degreeC for 7 days, and the deformation | transformation amount of the four corners after leaving is measured with a vernier caliper, and the average value of the heat deformation It was set as the value and made this value the measure of thermal stability.

(7) Antistatic property: According to JIS K-6911, the surface resistivity value of the product obtained by humidifying for 24 hours at a temperature of 23 ° C. and a humidity of 50% RH using a surface resistivity measuring instrument (R503) manufactured by Kawaguchi Corporation. It measured and made this value the measure of antistatic property.

(8) Scratches: The surface after overlapping two light diffusing sheets of the same material, applying a load of 300 g at a bottom area of 10 cm ² , and vibrating 60 times at 60 speeds in 1 minute width was observed for 1 minute. . The presence or absence of a scratch was observed and the thing with no scratch was made favorable for scratch resistance.

(9) Luminance: A light diffusing sheet obtained by arranging nine cold cathode tubes having a diameter of 5 mm and a length of 200 mm on a reflective sheet at intervals of 20 mm, and cutting them to a size of 180 mm x 180 mm at a position of 5 mm on the cold cathode tube. And a diffusion film, a prism sheet, and a brightness rising film were mounted thereon. In the dark room, the cold cathode tube was turned on, and 36 points of measurements were measured at 30 mm intervals using a luminance meter (BM-7) manufactured by Topcon Corporation at a position of 1000 mm from the light diffusion sheet, and the average value was obtained.

Evaluation other than the light-diffusion sheet was performed as follows.

(10) Refractive Index: The unmelted compound was measured under an atmosphere of wavelength 589 nm and 23 ° C with an Abbe refractometer. In addition, about the styrene copolymer, it measured at the temperature of 25 degreeC using the digital refractive index meter (RX-2000 by ATAGO company) using saturated potassium iodide aqueous solution as a contact liquid.

(11) Resin Composition of Styrene-Based Copolymer: A styrene-based copolymer was dissolved in heavy chloroform, prepared as a 2% solution, and used as a measurement sample, and ¹³ C was prepared using FT-NMR (FX-90Q type manufactured by Nippon Denshi Co., Ltd.). -NMR was measured and calculated from the peak areas of styrene and methyl methacrylate.

(12) Measurement of methacrylic acid monomer unit content in styrenic copolymer:

I. Measurement of the total amount of methacrylic acid monomer units and residual methacrylic acid in the styrenic copolymer

1) To 2 g of styrenic copolymer, 100 ml of a mixture of chloroform and ethanol (2: 1) is added and dissolved. 2) 0.5% phenolphthalein ethanol solution is added to this as an indicator, and it titrates further with 0.1N potassium hydroxide ethanol solution. The end point was when the color of the indicator did not disappear for 30 seconds. 3) 100 ml of a chloroform: ethanol mixed solution (2: 1) was taken as a blank test and the same operation as 2) was performed. 4) The methacrylic acid content in the styrene-based copolymer was obtained by the following formula.

Methacrylic acid content (%) = [{(A-B) × M} / (S × 1000)] × 100

A: Required amount (ml) for 1)

Proper amount (ml) required for B: 3)

S: mass (g) of styrenic copolymer

M: Mass (8.6 mg) of methacrylic acid equivalent to 1 ml of 0.1 N potassium hydroxide and ethanol solution

II. Measurement of the amount of methacrylic acid remaining in the styrenic copolymer

0.5 g of styrenic copolymer was dissolved in 10 ml of chloroform, N, N-dimethylformamide was measured as an internal standard, and measured under the following GC measurement conditions.

Device name: GC14B FID detector manufactured by Shimadzu Seisakusho

Column: glass column φ3 mm x 3 m

Filler: Diethylene Glycol Succinate

Carrier: Nitrogen

Temperature: column 110 ° C, inlet 180 ° C

III. The methacrylic acid monomer unit in a styrene-type copolymer obtained by subtracting the amount of the methacrylic acid monomer unit and the remaining methacrylic acid in the styrene-type copolymer measured in I, and the amount of the methacrylic acid in the styrene-based copolymer measured in II. It calculated | required as content. However, when the measured value of residual methacrylic acid in a styrene-type copolymer is less than 0.1 mass%, the methacrylic acid monomer unit content in a styrene-type copolymer was calculated | required as the amount of residual methacrylic acid to 0 mass%.

The multilayer sheet of this invention is excellent in dimensional stability, light resistance, light diffusivity, antistatic property, brightness, and recycling property, and is especially useful as a transmissive screen of screens, such as a projection television, and the light-diffusion plate of a liquid crystal television.

Also, Japanese Patent Application No. 2006-186445, filed July 6, 2006, Japanese Patent Application No. 2006-201419, filed July 25, 2006, and Japanese Patent Application, August 1, 2006 The entire contents of the specification, claims and summary of the application 2006-209946 are incorporated herein by reference, and are incorporated as a disclosure of the specification of the present invention.

Claims (16)

It is a light-diffusion sheet of a multilayer structure, The surface layer a and the double layer c contain the following (A) component, and the intermediate | middle layer b contains the (B) component. (A) component: The refractive index difference with this styrene-type copolymer with respect to 100 mass parts of styrene-type copolymers containing 20-100 mass% of styrene-type monomeric units and 80-0 mass% of the (meth) acrylic acid ester-type monomeric unit Styrene-based resin composition comprising 1 to 10 parts by mass of the undissolved compound having an average particle diameter of 5 to 15 µm, 0.1 to 2 parts by mass of the hindered amine compound, and 0.1 to 2 parts by mass of the benzotriazole compound. (B) component: Polyorgano which is an average particle diameter of 1-10 micrometers with respect to 100 mass parts of styrene-type copolymers containing 90-99 mass% of styrene-based monomer units and 10-1 mass% of (meth) acrylic-acid monomer units. The styrene resin composition containing 0.5-2.5 mass parts of siloxane crosslinked beads. Surface layer a and two-layer c contain (A) component of Claim 1, The intermediate | middle layer b grind | pulverized the multilayer sheet of Claim 1, 0-40 mass%, 90-99 mass% of styrene-based monomer units, and With respect to 100 mass parts of styrenic copolymers containing 10-1 mass% of methacrylic acid monomeric units, 1-the unmelted compound whose refractive index difference with this styrenic copolymer is 0.05-0.15 and an average particle diameter is 2-10 micrometers. The multilayer sheet containing 100-60 mass% of styrene resin compositions which contain 10 mass parts. The multilayer sheet of Claim 1 or 2 whose unmelted compound contained in (A) component is a crosslinked copolymer containing styrene and methyl methacrylate as a monomeric unit. The multilayer sheet of Claim 2 whose unmelted compound contained in (B) component is a crosslinked polymer containing methyl methacrylate as a monomeric unit. The multilayer sheet according to claim 1 or 2, wherein the hindered amine compound is bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate. The multilayer sheet according to claim 1 or 2, wherein the benzotriazole-based compound is 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol. The multilayer sheet of Claim 1 or 2 which contains 0.0005-0.5 mass part of benzoxazole type compounds further with respect to 100 mass parts of styrene copolymers in at least one of (A) component and (B) component. . The multilayer sheet according to claim 7, wherein the benzoxazole compound is 2,5-thiophendiyl (5-t-butyl-1,3-benzoxazole). The multilayer sheet of Claim 1 or 2 which contains 0.1-3 mass parts of amine surfactant further with respect to 100 mass parts of styrene-type copolymers of (A) component. The multilayer sheet according to claim 9, wherein the amine surfactant is N-hydroxyethyl-N- (2-hydroxyalkyl) amine. The polyether esteramide block copolymer according to claim 1 or 2, wherein the difference in refractive index with the styrene copolymer is 0.02 or less with respect to 100 parts by mass of the styrene copolymer of component (A), and an anion. The multilayer sheet containing 2 mass parts or less of system type surfactant and a non-amine nonionic surfactant. The multilayer sheet according to claim 11, wherein the polyetheresteramide block copolymer is a polyetheresteramide block copolymer comprising the following (F-A), (F-B) and (F-C) as monomer units. (F-A): aminocarboxylic acid or lactam of 6 or more carbon atoms, or a salt of diamine and dicarboxylic acid of 6 or more carbon atoms. (F-B): at least one diol compound of the following formulas (1) to (3). &Lt; Formula 1 >

Wherein R1 is an ethylene oxide group, R2 is an ethylene oxide group or a propylene oxide group, X is a halogen, an alkyl group (C1-6) or a sulfonic acid group or a metal salt thereof, L is an integer of 0-4, m and n represents an integer of 16 or more. (2)

Wherein R1 is an ethylene oxide group, R2 is an ethylene oxide group or a propylene oxide group, X is a halogen, an alkyl group (C1-6) or a sulfone group or a metal salt thereof, Y is an alkylene group (C1-6) , Alkylidene group (1 to 6 carbon atoms), cycloalkylidene group (7 to 17 carbon atoms), arylalkylidene group (7 to 17 carbon atoms), O, SO, SO ₂ , CO, S, CF ₂ , C (CF ₃ ) ₂ or NH, L represents an integer of 0 to 4, m and n represent an integer of 16 or more. (3)

In formula, R <1> is an ethylene oxide group, R <2> is an ethylene oxide group or a propylene oxide group, m and n represent the integer of 16 or more. (F-C): dicarboxylic acid having 4 to 20 carbon atoms. The compounding ratio of the anionic surfactant and non-amine nonionic surfactant in (A) component of Claim 11 is anionic surfactant / non-amine nonionic surfactant = 0.5 / 99.5-15 / 85 (mass ratio) Multi-layered sheet. The multilayer sheet according to claim 11, wherein the anionic surfactant in component (A) is an organic sulfonic acid metal salt having 10 to 14 carbon atoms, and the nonamine nonionic surfactant is glycerin fatty acid ester. The multilayer sheet according to claim 1 or 2, wherein each of the thicknesses of the multilayer configuration has a surface layer a and a two layer c of 0.005 to 0.5 mm and an intermediate layer b of 1 to 7 mm. The multilayer sheet according to claim 1 or 2, obtained by simultaneously extruding and processing the surface layer a, the intermediate layer b, and the double layer c.