JP2013043390A - Laminate and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate in which image display does take on a tinge of red, even when seen from an oblique direction in addition to a front direction.SOLUTION: The laminate is made by directly laminating a protective film made of polyolefin resin onto the mat surface of a mat film made of a thermoplastic resin composition containing a thermoplastic resin and light diffusing particles, wherein the content of the light diffusing particles falls into the range of 0.4 to 1.6 pts.wt. per 100 pts.wt. of the sum amount of the thermoplastic resin and the light diffusing particles.

Description

  The present invention relates to a laminate in which a mat film and a protective film are laminated and a method for producing the same.

  A mat film having a mat shape (uneven shape) on the film surface is often used in a liquid crystal display device as a light diffusion film. Patent Document 1 describes that a mat film made of polycarbonate resin is used as a light diffusion film. A mat film is usually formed by embossing roll transfer to form a predetermined mat shape, or by coating the surface of a base film with UV curable resin or thermosetting resin in which spherical beads are dispersed. What is formed.

  The mat film is also used as a protective film for a polarized light separating sheet which is disposed between a backlight unit of a liquid crystal display device and a liquid crystal panel and used for improving luminance. Since this polarized light separating sheet is usually about 100 μm thick even when it is thick, the rigidity of the sheet itself is not sufficient when it becomes a large area, and the self-supporting property becomes insufficient. In order to suppress these, it is usually the case that the sheet itself is bent or wavy due to the effect of heat, or that a rainbow pattern is generated due to interference when it comes into contact with the liquid crystal panel. A matte film made of polycarbonate resin is bonded to both surfaces of the sheet as a polarizing separation sheet protective film.

  A mat film made of a polycarbonate resin may cause scratches or dust on the mat surface of the mat film when laminated with a polarization separation sheet or transported. Therefore, usually, a protective film made of a peelable polyolefin resin is bonded to the mat surface of the mat film, and then the surface of the mat film that is not bonded to the protective film is bonded to the polarization separation sheet. Then, the protective film is peeled off from the mat surface. In many cases, the protective film is peeled off at the final stage of assembly of the liquid crystal display device, and accordingly, it is necessary to have appropriate adhesiveness and peelability to the matte film. The protective film is bonded to the matte film with one side of the protective film coated with a pressure-sensitive adhesive or adhesive, or one side of the pressure-sensitive adhesive layer added with pressure-sensitive adhesive in consideration of adhesiveness and peelability. It is usual to use the protective film which is contained in.

JP 2004-53998 A

  A protective film with a pressure-sensitive adhesive or adhesive coated on one side, or a protective film with a pressure-sensitive adhesive layer with a pressure-sensitive adhesive added on one side, has adequate adhesion and peelability to the matte film. However, if the protective film bonded to the mat film is peeled off from the mat film, there may be a part of the adhesive, adhesive or adhesive resin layer remaining on the mat film (adhesive residue). There is a possibility that it becomes a technical fault.

  The present inventors obtained a laminate in which a protective film made of a polyolefin resin was directly laminated on a mat surface of a mat film made of a thermoplastic resin. When the protective film was peeled from the laminate, the mat was It was found that no adhesive residue was generated on the film. In addition, the liquid crystal display device in which the matte film obtained by peeling the protective film from the laminate is disposed between the backlight unit and the liquid crystal panel has a natural color display when viewed from the front. However, it was newly found that the image display when viewed from an oblique direction may be reddish.

  Accordingly, the problem of the present invention is that no adhesive residue is generated on the mat film even when the protective film is peeled off, and the mat film obtained by peeling off the protective film is disposed in the liquid crystal display device. An object of the present invention is to provide a laminate in which an image display is not reddish when the liquid crystal display device is viewed from the front direction as well as from the front direction. Moreover, another subject of this invention is providing the manufacturing method which can manufacture the laminated body by which the protective film was laminated | stacked on the mat | matte surface of the mat film in one process.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

That is, the present invention relates to the following inventions.
(1) A protective film made of a polyolefin resin is directly laminated on a mat surface of a mat film made of a thermoplastic resin composition containing a thermoplastic resin and light diffusing particles, and the content of the light diffusing particles is A laminate comprising 0.4 to 1.6 parts by weight with respect to 100 parts by weight of the total amount of the thermoplastic resin and the light diffusing particles.
(2) When the absolute value of the difference between the refractive index of the thermoplastic resin and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D50 (μm), Δn and D50 are 0 .01 ≦ Δn × D50 ≦ 0.25 The laminate according to (1), which satisfies the relational expression:
(3) The laminate according to (1) or (2), wherein the mat film and the protective film are peelable.
(4) The thermoplastic resin is at least one selected from the group consisting of polycarbonate resins, acrylic resins, polyester resins, styrene resins, methyl methacrylate-styrene resins, ABS resins, and AS resins. The laminated body in any one of said (1)-(3).
(5) The laminate according to any one of (1) to (4), wherein the polyolefin resin is at least one selected from the group consisting of a polyethylene resin, a polypropylene resin, and a modified polyolefin resin that is a modified product thereof. body.
(6) The laminate according to any one of (1) to (5), wherein both surfaces of the protective film are mat surfaces.
(7) The laminate according to any one of (1) to (6), wherein the haze of the matte film is 90% or less.
(8) The in-plane retardation of the mat film is 30 nm or less, and the 60 ° specular gloss of the surface on which the protective film of the mat film is laminated is 60% or less. The laminated body of description.
(9) The laminate according to any one of (1) to (8), wherein the delamination force between the mat film and the protective film is 1 to 50 g / 25 mm width.
(10) The laminate according to any one of (1) to (9), which is produced by melt-coextrusion of a thermoplastic resin and a polyolefin resin.
(11) The laminate according to any one of (1) to (10), wherein a matte film obtained by peeling a protective film from the laminate is used in a liquid crystal display device.
(12) The laminate according to (11), wherein the mat film is used for protecting the polarization separation sheet in the liquid crystal display device.
(13) A thermoplastic resin and a polyolefin resin are melt-coextruded to obtain a film-like product, and inserted between the shaping roll and the touch roll so that the surface of the layer made of the polyolefin resin is in contact with the shaping roll. A method for producing a laminate, comprising forming a mat shape on a surface of a layer made of a plastic resin.
(14) A matte film obtained by peeling a protective film from the laminate according to any one of (1) to (12).

According to the present invention, since the mat film and the protective film are not bonded via an adhesive or the like, there is no so-called adhesive residue after the protective film is peeled off, and the mat film is obtained by peeling off the protective film. Is disposed in the liquid crystal display device, the image display when the liquid crystal display device is viewed from the front direction is not reddish, and the image display when viewed from the oblique direction is also reddish. Absent.
Moreover, according to the manufacturing method of this invention, shaping | molding of a mat | matte film and a protective film, and lamination | stacking of both films can be carried out in one process.

It is a typical side view which shows one Embodiment of the liquid crystal display device by which the mat | matte film of this invention is arrange | positioned. It is a schematic explanatory drawing which shows one Embodiment of the manufacturing method of the laminated body of this invention.

Hereinafter, the present invention will be described in detail.
The laminate of the present invention has a mat film and a protective film, and the protective film is directly laminated on the mat surface of the mat film. Here, the direct lamination means that the mat film and the protective film are laminated without using an adhesive layer or a pressure-sensitive adhesive layer. The mat film is made of a thermoplastic resin composition containing a thermoplastic resin and light diffusing particles. The protective film is made of a polyolefin resin. Hereinafter, the thermoplastic resin, the light diffusing particles, the polyolefin resin, and the laminate will be described in order.

[Thermoplastic resin]
The thermoplastic resin is made of a resin other than the polyolefin resin described later, and is a polycarbonate resin, acrylic resin, polyester resin, polystyrene resin, methyl methacrylate-styrene resin, ABS (acrylonitrile-butadiene-styrene copolymer). It is preferable that it is 1 or more types chosen from the group which consists of type | system | group resin and AS (acrylonitrile styrene copolymer) type | system | group resin. As the resin, a resin having good transparency is preferable. Among them, from the viewpoint of having high transparency, excellent impact resistance, heat resistance, dimensional stability, flame retardancy, and few optical foreign matters. It is preferable to use a polycarbonate resin. A thermoplastic resin may mix 2 or more types of the said resin in the range which does not inhibit transparency and does not impair the effect of this invention.

<Polycarbonate resin>
As the polycarbonate resin, for example, it is preferable to use an aromatic polycarbonate resin excellent in heat resistance, mechanical strength, transparency, and the like.
As an aromatic polycarbonate resin, for example, a resin obtained by reacting a dihydric phenol and a carbonate precursor by an interfacial polycondensation method or a melt transesterification method, a carbonate prepolymer was polymerized by a solid phase transesterification method. Examples thereof include a resin and a resin obtained by polymerizing by a ring-opening polymerization method of a cyclic carbonate compound.

  Examples of the dihydric phenol include hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis {(4-hydroxy-3,5-dimethyl) phenyl} methane, 1,1- Bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane (commonly called 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-bis {(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, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4 -Methylpentane, 1,1-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) fluorene, 9,9-bis {(4-hydroxy 3-methyl) phenyl} fluorene, α, α′-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenylsulfoxide, 4 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, etc., and these may be used alone or in combination of two or more. can do.

  Among them, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3 -Methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) It is preferable to use a dihydric phenol selected from the group consisting of −3,3,5-trimethylcyclohexane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene alone or in combination, Use of bisphenol A alone, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, At least one selected from the group consisting of enol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, and α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene. The combined use with a monohydric phenol is preferred.

  As the carbonate precursor, for example, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like.

<Acrylic resin>
For example, methacrylic resin is used as the acrylic resin. The methacrylic resin is a polymer mainly composed of a methacrylic acid ester, and may be a homopolymer of a methacrylic acid ester, or a methacrylic acid ester of 50% by weight or more and other monomers of 50% by weight or less. A copolymer may also be used. Here, as the methacrylic acid ester, an alkyl ester of methacrylic acid is usually used.

  The preferred monomer composition of the methacrylic resin is 50 to 100% by weight of alkyl methacrylate, 0 to 50% by weight of alkyl acrylate, and 0 to 49% by weight of other monomers based on all monomers. More preferably, the alkyl methacrylate is 50 to 99.9% by weight, the alkyl acrylate is 0.1 to 50% by weight, and other monomers are 0 to 49% by weight.

  Here, examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and the like. The alkyl group usually has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. It is. Of these, methyl methacrylate is preferably used.

  Examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. The alkyl group usually has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. is there.

The monomer other than alkyl methacrylate and alkyl acrylate may be, for example, a monofunctional monomer, that is, a compound having one polymerizable carbon-carbon double bond in the molecule, Although it may be a polyfunctional monomer, that is, a compound having at least two polymerizable carbon-carbon double bonds in the molecule, a monofunctional monomer is preferably used.
Examples of the monofunctional monomer include styrene monomers such as styrene, α-methylstyrene, and vinyl toluene, alkenyl cyanide such as acrylonitrile and methacrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, N -Substituted maleimide and the like.
Examples of polyfunctional monomers include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane triacrylate, allyl acrylate, allyl methacrylate, and cinnamon. Alkenyl esters of unsaturated carboxylic acids such as allyl acids, polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate, aromatic polyalkenyl compounds such as divinylbenzene, etc. Can be mentioned.

  In addition, as for said alkyl methacrylate, alkyl acrylate, and monomers other than these, respectively, you may use those 2 or more types as needed.

  From the viewpoint of heat resistance, the methacrylic resin preferably has a glass transition temperature of 70 ° C. or higher, more preferably 80 ° C. or higher, and further preferably 90 ° C. or higher. This glass transition temperature can be appropriately set by adjusting the type of monomer and the ratio thereof.

  The methacrylic resin can be prepared by polymerizing the monomer component by a method such as suspension polymerization, emulsion polymerization, or bulk polymerization. At that time, it is preferable to use an appropriate chain transfer agent at the time of polymerization in order to obtain a suitable glass transition temperature or to obtain a melt viscosity exhibiting a moldability to a suitable laminate. What is necessary is just to determine the addition amount of a chain transfer agent suitably according to the kind of monomer, its ratio, etc.

<Rubber particles>
Rubber particles can also be blended with the acrylic resin. Here, as the rubber particles, for example, acrylic rubber particles, butadiene rubber particles, styrene-butadiene rubber particles, and the like can be used, and among them, acrylic rubber from the viewpoint of weather resistance and durability. Particles are preferably used.

The acrylic rubber particle is a particle containing an elastic polymer mainly composed of an acrylate ester as a rubber component, and may be a particle having a single layer structure made of only this elastic polymer. It may be a multilayered particle having a layer and a polymer layer mainly composed of, for example, a methacrylic acid ester, but is a multilayered particle from the viewpoint of the surface hardness of a mat film made of an acrylic resin. Is preferred.
The elastic polymer may be a homopolymer of an acrylate ester or a copolymer of 50% by weight or more of an acrylate ester and 50% by weight or less of other monomers. . Here, as the acrylic ester, an alkyl ester of acrylic acid is usually used.

  A preferable monomer composition of the elastic polymer mainly composed of an acrylate ester is 50 to 99.9% by weight of alkyl acrylate, 0 to 49.9% by weight of alkyl methacrylate, based on all monomers, The monofunctional monomer other than these is 0 to 49.9% by weight, and the polyfunctional monomer is 0.1 to 10% by weight.

Here, the alkyl acrylate in the elastic polymer is, for example, the same as the examples of the alkyl acrylate previously mentioned as the monomer component of the methacrylic resin, and the alkyl group usually has 1 to 8 carbon atoms. Preferably it is 4-8.
The alkyl methacrylate in the elastic polymer is, for example, the same as the examples of alkyl methacrylates previously mentioned as the monomer component of the methacrylic resin, and the alkyl group usually has 1 to 8 carbon atoms, preferably Is 1-4.

  Examples of the monofunctional monomer other than alkyl acrylate and alkyl methacrylate in the elastic polymer include, for example, monofunctional monomers other than alkyl methacrylate and alkyl acrylate mentioned above as the monomer component of methacrylic resin. This is the same as the example. Of these, styrene monomers such as styrene, α-methylstyrene and vinyltoluene are preferably used.

  The polyfunctional monomer in the elastic polymer is, for example, the same as the examples of the polyfunctional monomer previously mentioned as the monomer component of the methacrylic resin, among them, an alkenyl ester of an unsaturated carboxylic acid, Polyalkenyl esters of polybasic acids are preferably used.

  The alkyl acrylate, the alkyl methacrylate, the monofunctional monomer other than these, and the polyfunctional monomer in the elastic polymer may each be used in combination of two or more as necessary.

When the acrylic rubber particles having a multilayer structure are used, a preferred example thereof is a polymer layer mainly composed of methacrylic acid ester outside the above-mentioned elastic polymer layer mainly composed of acrylate ester. That is, the above-mentioned elastic polymer mainly composed of an acrylic ester is used as an inner layer, and the polymer mainly composed of a methacrylic ester is used as an outer layer. Here, as the methacrylic acid ester which is a monomer component of the polymer in the outer layer, alkyl methacrylate is usually used.
The outer layer polymer is usually formed at a ratio of 10 to 400 parts by weight, preferably 20 to 200 parts by weight with respect to 100 parts by weight of the inner layer elastic polymer. By setting the polymer of the outer layer to 10 parts by weight or more with respect to 100 parts by weight of the elastic polymer of the inner layer, the elastic polymer is hardly aggregated, and the transparency of the mat film is improved.

  The preferred monomer composition of the polymer of the outer layer is based on all monomers, the alkyl methacrylate is 50 to 100% by weight, the alkyl acrylate is 0 to 50% by weight, and other monomers are 0 to 0% by weight. 50% by weight, and 0 to 10% by weight of the polyfunctional monomer.

  The alkyl methacrylate in the polymer of the outer layer is, for example, the same as the examples of alkyl methacrylate previously mentioned as the monomer component of the methacrylic resin, and the alkyl group usually has 1 to 8 carbon atoms, preferably 1-4. Of these, methyl methacrylate is preferably used.

  The alkyl acrylate in the polymer of the outer layer is, for example, the same as the examples of the alkyl acrylate mentioned above as the monomer component of the methacrylic resin, and the alkyl group usually has 1 to 8 carbon atoms, preferably 1-4.

  Examples of monomers other than alkyl methacrylate and alkyl acrylate in the polymer of the outer layer include, for example, monofunctional monomers other than alkyl methacrylate and alkyl acrylate mentioned above as the monomer component of methacrylic resin. It is the same as that of an example, and as a polyfunctional monomer, it is the same as that of the example of the polyfunctional monomer previously mentioned as a monomer component of a methacryl resin, for example.

  In addition, as for the alkyl methacrylate, the alkyl acrylate, the monomer other than these, and the polyfunctional monomer in the polymer of the outer layer, two or more kinds thereof may be used as necessary.

  Further, as a suitable example of the acrylic rubber particles having a multilayer structure, an inner layer of the above-mentioned acrylic ester mainly composed of the above-mentioned acrylic ester which is the inner layer of the above-mentioned two-layer structure, and a layer mainly composed of methacrylic ester. A polymer having a coalesced layer, that is, a polymer mainly composed of methacrylic acid ester is used as an inner layer, and the above-mentioned elastic polymer mainly comprising acrylate ester is used as an intermediate layer, and Mention may also be made of at least a three-layer structure in which the coalescence is the outer layer. Here, as a methacrylic acid ester which is a monomer component of the polymer of the inner layer, alkyl methacrylate is usually used. The polymer of the inner layer is usually formed at a ratio of 10 to 400 parts by weight, preferably 20 to 200 parts by weight, with respect to 100 parts by weight of the elastic polymer of the intermediate layer.

  A preferable monomer composition of the polymer of the inner layer is 70 to 100% by weight of alkyl methacrylate, 0 to 30% by weight of alkyl acrylate, and 0 to 30% of other monomers based on all monomers. 30% by weight, and 0 to 10% by weight of the polyfunctional monomer.

The alkyl methacrylate in the polymer of the inner layer is, for example, the same as the examples of alkyl methacrylate previously mentioned as the monomer component of the methacrylic resin, and the alkyl group usually has 1 to 8 carbon atoms, preferably 1-4. Of these, methyl methacrylate is preferably used.
In addition, the alkyl acrylate in the polymer of the inner layer is, for example, the same as the examples of the alkyl acrylate previously mentioned as the monomer component of the methacrylic resin, and the alkyl group usually has 1 to 8 carbon atoms. Preferably it is 1-4.

  Examples of monomers other than alkyl methacrylate and alkyl acrylate in the polymer of the inner layer include, for example, monofunctional monomers other than alkyl methacrylate and alkyl acrylate mentioned above as the monomer component of methacrylic resin. The examples are the same as the examples, and examples of the polyfunctional monomer are the same as the examples of the polyfunctional monomer described above as the monomer component of the methacrylic resin.

  In addition, as for the alkyl methacrylate, the alkyl acrylate, the monomer other than these, and the polyfunctional monomer in the polymer of the inner layer, two or more kinds thereof may be used as necessary.

The acrylic rubber particles can be prepared by polymerizing the monomer component of the elastic polymer mainly composed of the above-described acrylic ester by at least one reaction by an emulsion polymerization method or the like. At this time, as described above, when a polymer layer mainly composed of methacrylic acid ester is formed outside the elastic polymer layer, the monomer component of the outer layer polymer is added to the elastic polymer layer. What is necessary is just to graft to the said elastic polymer by making it superpose | polymerize by reaction of at least 1 step | paragraph by emulsion polymerization method etc. in presence of a polymer.
Further, as described above, when a polymer layer mainly composed of methacrylic acid ester is formed inside the elastic polymer layer, first, the monomer component of the polymer in the inner layer is Polymerization is performed by at least one stage reaction by an emulsion polymerization method or the like, and then the monomer component of the elastic polymer is polymerized by at least one stage reaction by an emulsion polymerization method or the like in the presence of the resulting polymer. In the presence of the resulting elastic polymer, the monomer component of the outer layer polymer is polymerized in an at least one-stage reaction by an emulsion polymerization method or the like. To be grafted to the elastic polymer. When the polymerization of each layer is performed in two or more stages, it is sufficient that the monomer composition as a whole is within a predetermined range, not the monomer composition of each stage.

  Regarding the particle diameter of the acrylic rubber particles, the average particle diameter of the elastic polymer layer mainly composed of acrylic acid ester in the rubber particles is preferably 0.01 to 0.4 μm, more preferably 0. 0.05 to 0.3 μm, more preferably 0.07 to 0.25 μm. If the average particle size of the elastic polymer layer is larger than 0.4 μm, the transparency of the matte film made of acrylic resin is lowered and the transmittance is lowered. Further, if the average particle size of the elastic polymer layer is smaller than 0.01 μm, the surface hardness of the mat film is lowered and the surface is easily damaged, which is not preferable.

In addition, the average particle diameter is a portion obtained by mixing acrylic rubber particles with a methacrylic resin to form a film, dyeing the elastic polymer layer with ruthenium oxide in the cross section, and observing with an electron microscope. It can be calculated from the diameter.
That is, when acrylic rubber particles are mixed with methacrylic resin and the cross section thereof is dyed with ruthenium oxide, the methacrylic resin of the parent phase is not dyed, and the polymer mainly composed of methacrylic acid ester on the outer side of the elastic polymer layer. In this case, the outer layer polymer is not dyed, and only the elastic polymer layer is dyed, so that the dye is dyed in this way, and from the diameter of the portion observed in an approximately circular shape by an electron microscope, The particle diameter can be determined. When a polymer layer mainly composed of methacrylic acid ester is present inside the elastic polymer layer, the polymer of the inner layer is not dyed and the outer elastic polymer layer is dyed 2 In this case, the outer diameter of the two-layer structure, that is, the outer diameter of the elastic polymer layer may be considered.

  The content ratio of the rubber particles with respect to the acrylic resin is 40% by weight or less, preferably 30% by weight or less of the entire acrylic resin. If the content ratio of the rubber particles is larger than 40% by weight of the whole acrylic resin, the surface hardness of the mat film is lowered and the surface is easily damaged.

<Polyester resin>
Examples of the polyester-based resin include polyethylene terephthalate and polyethylene naphthalate, and examples thereof include crystalline polyester and amorphous polyester. From the viewpoint of transparency, an amorphous resin is preferable.
The polyester resin can be composed of a polyester resin composition composed of a crystalline polyester and an amorphous polyester. The polyester resin is produced by polycondensation of a dibasic acid and a polyhydric alcohol.
Examples of the dibasic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid.
Examples of the polyhydric alcohol include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, pentaethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol, neopentyl glycol. Diols such as
Said dibasic acid and polyhydric alcohol are used by arbitrary combinations. Specifically, terephthalic acid / ethylene glycol copolymer, terephthalic acid / ethylene glycol / 1,4-cyclohexane dimethanol terpolymer, 2,6-naphthalenedicarboxylic acid / ethylene glycol copolymer, terephthalate Examples include acid / 1,4-butanediol copolymer.
Examples of the crystalline polyester include a resin marketed under the trade name “Byron” (manufactured by Toyobo Co., Ltd.).
Examples of the amorphous polyester include amorphous polyethylene terephthalate (so-called APET) and terephthalic acid / ethylene glycol / 1,4-cyclohexanedimethanol terpolymer (example: trade name “PETG” (yeast Man Chemical Co., Ltd.)).

<Polystyrene resin>
The polystyrene-based resin is a polymer containing 50% by mass or more, preferably 70% by mass or more of styrene units as a structural unit, and a part thereof can be copolymerized with styrene as long as it contains 50% by mass or more of styrene units. Such a copolymer may be substituted with a monofunctional unsaturated monomer unit.

Examples of the copolymerizable monofunctional unsaturated monomer include ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, and the like. Methacrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, etc .; methacryl Examples thereof include unsaturated acids such as acid and acrylic acid; α-methylstyrene, methacrylonitrile, maleic anhydride, phenylmaleimide, cyclohexylmaleimide and the like. Moreover, this copolymer may further contain a glutaric anhydride unit and a glutarimide unit.
Further, a blend of a diene rubber, an acrylic rubber or the like as a rubbery polymer may be contained in the polymer or copolymer described above.

<Methyl methacrylate-styrene resin>
Examples of the methyl methacrylate-styrene resin include, for example, a styrene unit content of 20% by mass to 95% by mass and a methyl methacrylate unit content of 80% by mass to 5% by mass, preferably a styrene unit content of 70% by mass or more. And a copolymer having a methyl methacrylate unit content of 30% by mass or less.

<AS resin>
Examples of the AS (acrylonitrile-styrene) resin include a copolymer in which a monomer unit derived from acrylonitrile and a monomer unit derived from styrene are randomly copolymerized. The content of monomer units derived from acrylonitrile is usually 2 to 50% by weight (that is, the content of monomer units derived from styrene is usually 98 to 50% by weight), preferably 20 to 30% by weight. (That is, the content of monomer units derived from styrene is preferably 80 to 70% by weight). However, the total of the monomer units contained in the AS resin is 100% by weight.

<ABS resin>
Examples of the ABS (acrylonitrile-butadiene-styrene) resin include a copolymer obtained by graft polymerization of the olefin rubber (for example, polybutadiene rubber) to about 40% by weight or less on the AS resin described above.
In addition, in order to obtain good transparency, from the viewpoint of bringing the refractive index value of the resin component closer to the refractive index value of the rubber component, a copolymer of styrene, methyl methacrylate and other copolymerizable monomers as the resin component. A so-called transparent ABS which is a polymer is preferred.
Examples of the copolymerizable monomer include acrylonitrile. Moreover, about transparent ABS, what was disclosed by Unexamined-Japanese-Patent No. 2006-265406 is mentioned, for example.

[Light diffusion particles]
The light diffusing particle (light diffusing agent) is not particularly limited as long as it is a particle having a refractive index different from that of the above-described thermoplastic resin and can diffuse transmitted light, and any kind can be used. For example, glass beads, silica particles, aluminum hydroxide particles, calcium carbonate particles, barium sulfate particles, titanium oxide particles, inorganic particles such as talc, styrene polymer particles, cross-linked acrylic polymer particles, siloxane polymer particles And resin particles.

  The content of the light diffusing particles in the thermoplastic resin composition is 0.4 to 1.6 parts by weight with respect to 100 parts by weight of the total amount of the thermoplastic resin and the light diffusing particles, and 0.5 to 1. The amount is more preferably 0 part by weight, and further preferably 0.5 to 0.8 part by weight. When the content of the light diffusing particles is less than 0.4 parts by weight, the image display when the liquid crystal display device provided with the mat film obtained by peeling the protective film from the laminate is viewed from the front is reddish. The image display appears reddish when viewed from an oblique direction without being tinged. When the content of the light diffusing particles exceeds 1.6 parts by weight, the image display when the liquid crystal display device on which the matte film obtained by peeling the protective film is installed is viewed from an oblique direction may be reddish. The image display appears reddish when viewed from the front.

  The cumulative 50% particle diameter (D50) of the light diffusing particles is preferably 10 μm or less, and more preferably 0.3 to 8 μm.

  The absolute value (Δn) of the difference between the refractive index of the thermoplastic resin and the refractive index of the light diffusing particles is preferably 0.01 to 0.20, more preferably 0.02 to 0.18. preferable.

  It is preferable that Δn and D50 satisfy the relational expression of 0.01 ≦ Δn × D50 ≦ 0.25. By satisfying the relational expression, it is possible to more effectively suppress the redness of the image display when the liquid crystal display device on which the mat film is disposed is viewed from an oblique direction. It is more preferable that Δn and D50 satisfy the relational expression when they are within the above-mentioned ranges.

  D50 can be measured by a Fraunhofer diffraction method of laser light source forward scattered light using a Nikkiso Co., Ltd. microtrack particle size analyzer (model 9220FRA). In measurement, about 0.1 g of light diffusing particles are dispersed in methanol to obtain a dispersion, and after irradiating the dispersion with ultrasonic waves for 5 minutes, the dispersion is put into a sample of the microtrack particle size analyzer. Measurement may be performed by putting it in the mouth. In addition, D50 is the particle diameter of the particle | grains which measure the particle diameter and volume of all the particles, accumulate | accumulate a volume sequentially from the thing of a small particle diameter, and this accumulation volume becomes 50% with respect to the total volume of all the particles. .

[Polyolefin resin]
The polyolefin resin is preferably at least one selected from the group consisting of a polyethylene resin, a polypropylene resin, and a modified polyolefin resin that is a modified product thereof. When the laminate of the present invention is used for a liquid crystal display device, the protective film is finally peeled off from the matte film, and therefore, it is preferable to use a polyethylene resin or a polypropylene resin that is available at a relatively low cost.
From the viewpoint of moldability, the polyolefin resin preferably has a melt viscosity (b) at a shear rate of 260 ° C. and 100 sec ⁻¹ of 80 to 4000 Pa · sec, more preferably 100 to 2000 Pa · sec. More preferably, it is 100-1400 Pa.sec.

<Polyethylene resin>
Examples of the polyethylene resin include an ethylene homopolymer, an ethylene-propylene random copolymer, and an ethylene-α-olefin copolymer.
Examples of the α-olefin used in the ethylene-α-olefin copolymer include 1-butene, 2-methyl-1-propene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2 -Ethyl-1-butene, 2,3-dimethyl-1-butene, 1-pentene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl -1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, Ethyl-1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl Examples include -1-butene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene. Of these, 1-butene, 1-pentene, 1-hexene, and 1-octene are preferably used.

<Polypropylene resin>
Examples of the polypropylene resin include propylene homopolymer, propylene-ethylene random copolymer, propylene-α-olefin random copolymer, propylene-ethylene-α-olefin copolymer, propylene homopolymer component or mainly. Examples thereof include a polypropylene-based copolymer composed of a copolymer component composed of propylene and a copolymer component of propylene and ethylene and / or α-olefin. These polypropylene resins may be used alone or in combination of two or more.

  Examples of the α-olefin used for the polypropylene resin include compounds similar to the α-olefin used for the ethylene-α-olefin copolymer.

<Modified polyolefin resin>
For example, the modified polyolefin resin is obtained by modifying a polyolefin with a modifying compound such as maleic anhydride, dimethyl maleate, diethyl maleate, acrylic acid, methacrylic acid, tetrahydrophthalic acid, glycidyl methacrylate, hydroxyethyl methacrylate, or methyl methacrylate. can get. The polyolefin used here may be a known polyolefin. For example, ethylene-based resin, isotactic polypropylene, syndiotactic polypropylene, random type polypropylene containing a comonomer, block type polypropylene by multistage polymerization, poly (4-methyl- 1-pentene), poly (1-butene) and the like.

As a method for producing the polyolefin resin, a known polymerization method using a known olefin polymerization catalyst is used. For example, slurry polymerization method, solution polymerization method, bulk polymerization method, gas phase polymerization method, etc. using complex catalysts such as Ziegler-Natta catalysts, metallocene complexes and nonmetallocene complexes, and radical initiators are used. Examples thereof include bulk polymerization and solution polymerization.
Moreover, you may use the commercially available polyolefin resin applicable to the polyolefin resin of this invention.

  The thermoplastic resin and polyolefin resin may contain other components such as antioxidants, ultraviolet absorbers, organic dyes, inorganic dyes, pigments, antistatic agents, surfactants, etc. as necessary. May be.

[Laminate]
The laminate of the present invention is obtained by directly laminating a protective film made of a polyolefin resin on a mat surface of a mat film made of a thermoplastic resin composition.

  The thickness of the laminate is preferably 30 to 400 μm, more preferably 50 to 300 μm, and still more preferably 70 to 250 μm. If the thickness is less than 30 μm, the rigidity of the laminate itself becomes low, so that wrinkles are likely to enter the laminate, and floating or the like tends to occur in the set state. When the thickness is greater than 400 μm, the manufacturing cost of the laminate increases, or when the obtained laminate is bonded to the polarization separation sheet, the thickness of the polarization separation sheet after bonding becomes thick, and as a result, the liquid crystal panel There is a possibility that the thickness of the film becomes thick.

In the laminate, the thickness of the mat film is preferably 60% or more, more preferably 70% or more, and 80% or more of the thickness of the entire laminate. More preferably, it is. When the thickness of the mat film is less than 60% of the total thickness of the laminate, for example, when transferring the mat shape to the mat film through the protective film, a sufficient mat shape cannot be transferred to the mat film. There is a fear.
Moreover, it is preferable that the thickness of a protective film is 5-50 micrometers, and it is more preferable that it is 10-40 micrometers. If the thickness is larger than 50 μm, for example, when transferring the mat shape to the mat film through the protective film, there is a possibility that a sufficient mat shape cannot be transferred to the mat film. If the thickness is less than 5 μm, the protective function of the protective film is There is a risk of lowering or breaking during peeling.

  In the laminate, the matte film and the protective film can be peeled off. Here, peelable means that the matte film and the protective film directly laminated can be peeled off from one film and separated into separate films.

In the laminate, the delamination force between the mat film and the protective film is preferably 5 to 50 g / 25 mm width, more preferably 5 to 30 g / 25 mm width, and 5 to 10 g / 25 mm width. Further preferred.
If the delamination force is lower than 5 g / 25 mm width, the protective film may be peeled off from the laminate when an external force is applied such as when the laminate is wound, transported, or cut. If it is too high, the matte film may be damaged when the protective film is peeled off.

  The haze of the matte film obtained by peeling the protective film from the laminate is preferably 90% or less, and more preferably 85% or less. If it exceeds 90%, when this film is used in a liquid crystal display device, the screen may be tinted and image quality may be deteriorated. Further, if the haze is lower than 25%, a sufficient antiglare effect may not appear.

The in-plane retardation value of incident light at a wavelength of 590 nm of the mat film is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.
When the mat film obtained by peeling off the protective film in the present invention is used in a liquid crystal display device, the light used for the liquid crystal display is polarized light, so that it is desirable that the optical distortion is small, and the retardation value is 30 nm or less. It is preferable that For example, when used as a polarizing separation sheet protective film in a liquid crystal display device, the retardation value is preferably 30 nm or less, and preferably 20 nm or less so as not to disturb the polarization direction of the polarized light emitted from the polarizing separation sheet as much as possible. More preferred is 10 nm or less.

  The 60-degree specular gloss on the surface of the mat film on which the protective film is laminated is preferably 60% or less, and more preferably 50% or less. If the 60-degree specular gloss exceeds 60%, a rainbow pattern due to interference may occur when the mat film and the liquid crystal panel come into contact with each other.

  In the surface roughness on the mat surface of the mat film, the arithmetic average roughness (Ra) is preferably 0.2 to 6 μm, more preferably 0.7 to 6 μm, and the maximum height roughness ( Rz) is preferably 0.7 to 30 μm, more preferably 3 to 30 μm, and the average length (RSm) of the contour curve element is preferably 80 to 320 μm, preferably 80 to 300 μm. More preferably. If each of the roughness values is lower than a predetermined range, a sufficient antiglare effect may not appear. Moreover, when it exceeds each predetermined range, there exists a possibility that transparency may fall.

The matte film obtained by peeling off the protective film is used in liquid crystal display devices for the purpose of diffusing action, turning action, prevention of sticking with other members, and protecting the surface of other members. For example, it is incorporated in a backlight unit. Used as a light diffusing sheet, a light diffusing film, a polarizing plate protective film, a retardation film, a brightness enhancement film, a reflective film, a light guide plate or a polarizing separation sheet protective film. Among these, the use as a polarizing separation sheet protective film is preferable.
In order to use the mat film as a polarizing separation sheet protective film, first, the protective film laminated on the mat surface of the mat film is peeled to obtain a mat film, and then the obtained mat film is used as at least one of the polarizing separation sheets. What is necessary is just to paste on the surface. When one surface of the mat film is a mat surface, the mat surface may be the outermost surface, that is, a surface that is not the mat surface may be bonded to the polarization separation sheet, and both surfaces of the mat film may be mat surfaces. In this case, either one of the mat surfaces may be bonded to the polarization separation sheet. Further, the mat film bonded to the polarization separation sheet may be damaged or dust may be attached to the mat surface when it is bonded to the polarization separation sheet or transported. Therefore, the laminate is first bonded to the polarization separation sheet so that the mat film surface of the laminate becomes the bonding surface, and then the protective film is peeled off from the laminate in the final stage of assembly of the liquid crystal display device. May be.

  The laminate or matte film is bonded to the polarized light separating sheet by applying an adhesive or an adhesive to the laminated surface of the laminated body or the mat film, or the bonding surface of the polarized light separating sheet. Or it is preferable to interpose an adhesive layer or an adhesive layer between the matte film. Moreover, you may interpose the adhesive resin layer which added the adhesive. The pressure-sensitive adhesive or adhesive is not particularly limited, and may be appropriately selected according to the required pressure-sensitive adhesive force or adhesive force.

  A liquid crystal display device in which a matte film obtained by peeling the protective film from the laminate is placed between the backlight unit and the liquid crystal panel, the image display is red when viewed from an oblique direction as well as the front direction. You wo n’t be charged. The following reasons can be considered as this reason. The light transmitted through the liquid crystal panel in the oblique direction from the backlight is strongly reddish, while the light transmitted through the mat film made of the thermoplastic resin composition containing the light diffusing particles is strongly blued in the oblique direction. The light transmitted through the backlight and the liquid crystal panel in an oblique direction has a strong reddish phenomenon, and the light transmitted through the mat film is a phenomenon in which the blue color is strongly scattered in the oblique direction. Are offset (compensated) with each other, and as a result, it is presumed that they will not be reddish when viewed from an oblique direction as well as the front direction.

  One embodiment of a liquid crystal display device in which a mat film is disposed is shown in FIG. The liquid crystal display device (1) includes a backlight unit (9) and a liquid crystal panel (30) disposed on the front side of the backlight unit (9). The backlight unit (9) includes a matte film (3) as a polarization separation sheet protective film and a light source device (50) disposed on the back side of the matte film (3).

  The liquid crystal panel (30) includes a liquid crystal cell (20) in which a liquid crystal (11) is sealed between a pair of upper and lower transparent electrodes (12) and (13) arranged in parallel and spaced apart from each other. The liquid crystal cell (20) includes polarizing plates (14) and (15) disposed on both upper and lower sides. These constituent members (11), (12), (13), (14), and (15) constitute an image display unit. An alignment film (not shown) is laminated on the inner surfaces (surfaces on the liquid crystal side) of the transparent electrodes (12) and (13).

When the voltage is not applied between the pair of transparent electrodes (12) and (13), the molecules of the liquid crystal (11) are substantially perpendicular to the transparent electrodes (12) and (13). In the state where a voltage is applied between the pair of transparent electrodes (12) and (13), the transparent electrodes (12) and (13) are substantially parallel to each other (including parallel shapes). ) (Orienting in a substantially horizontal direction). That is, as the liquid crystal cell (20), a vertical alignment liquid crystal cell is used.

  The said backlight unit (9) is arrange | positioned at the lower surface side (back side) of the said lower polarizing plate (15). The backlight unit (9) has a rectangular box shape in plan view and a thin box-shaped lamp box (5) whose upper surface (front side) is open, and a lamp box (5) spaced apart from each other. A plurality of light sources (2), a mat film (3) disposed on the upper side (front side) of the plurality of light sources (2), the mat film (3), and the liquid crystal panel (30). A polarization separation sheet (40) disposed therebetween, and a light collecting optical member (4) disposed between the mat film (3) and the light source (2). The mat film (3) and the light collecting optical member (4) are placed and fixed to the lamp box (5) so as to close the open surface. The polarized light separating sheet (40) is laminated and integrated on the front surface of the mat film (3) via an adhesive layer (41), and constitutes a laminated optical member together with the mat film (3). The mat film is preferably arranged in the backlight unit (9) so that the surface not in contact with the adhesive layer becomes the mat surface. When one surface of the mat film is a mat surface, the mat film may be disposed in the backlight unit so that the mat surface is not in contact with the adhesive layer. When is a mat surface, the mat film may be arranged in the backlight unit so that any one of the mat surfaces is a surface not in contact with the adhesive layer. A light reflecting layer (not shown) is provided on the inner surface of the lamp box (5). In the embodiment of FIG. 1, the light source device (50) includes a plurality of light sources (2) disposed on the back side of the mat film (3) and a lamp box (5).

  In the embodiment, the matte film (3) has the polarization separation sheet (40) laminated on the front side of the mat film (3) via the adhesive layer (41), and the polarization separation sheet (40). The liquid crystal panel (30) is disposed on the front side of the polarization separation sheet. However, the present invention is not particularly limited to this arrangement, and the polarization separation sheet (40) is also disposed on the front side of the polarization separation sheet (40). Similarly to the back side, the mat film (3) may be laminated via the adhesive layer (41).

  In the said embodiment, although the arrangement | positioning aspect (refer FIG. 1) with which the said mat | matte film (3) and the said condensing optical member (4) were piled up in the contact state is employ | adopted, especially in such an arrangement | positioning aspect. For example, the members (3) and (4) are parallel to each other in a non-contact state through a slight air layer between the mat film (3) and the light collecting optical member (4). You may employ | adopt the structure arrange | positioned in the shape. Moreover, as a condensing optical member (4), the prism sheet provided with the condensing function which collects the incident light from a light source (2) in a front direction, for example, the incident light from a light source (2) is collected in a front direction Examples include a light diffusion sheet having a light collecting function.

Whether the image display looks reddish when viewed from the front and diagonal directions of a liquid crystal display device with a mat film between the backlight unit and the liquid crystal panel depends on the spectral orientation performance of the mat film. Can be confirmed.
First, light is incident on the matte film from the front direction. Next, the spectral transmittance of light transmitted in the front direction of the mat film is measured, and the ratio of the amount of transmitted light (red light) with a wavelength of 610 nm to the transmitted light (blue light) with a wavelength of 470 nm based on the obtained spectral transmittance. May be calculated. Hereinafter, the calculated light quantity ratio is defined as spectral alignment performance. If the spectral orientation performance is 1.5 to 4.0, the image display will not be reddish when viewed from an oblique direction as well as the front direction. When the spectral alignment performance is less than 1.5, the ratio of blue light in the front direction is large and the ratio of blue light in the oblique direction is small, so that the light transmitted through the mat film in the front direction is sufficiently bluish. Thus, the image display does not appear reddish when viewed from the front direction, but the light transmitted through the oblique direction is not sufficiently bluish, and the image display appears reddish when viewed from the oblique direction. When the spectral alignment performance exceeds 4.0, the ratio of blue light in the front direction is small and the ratio of blue light in the oblique direction is large, so that the light transmitted through the mat film in the oblique direction is sufficiently bluish. The image display does not appear reddish when viewed from an oblique direction, but the light transmitted in the front direction is not sufficiently bluish, and the image display appears reddish when viewed from the front direction. In addition, if the ratio of blue light in the oblique direction is large, the light transmitted through the mat film in the oblique direction is excessively bluish, and the image display may appear bluish when viewed from the oblique direction. .
In order to achieve a more natural color display when the image display is viewed from either the front direction or the oblique direction, the spectral alignment performance is preferably 1.6 to 3.0. More preferably, it is 6-2.0.

  The matte film obtained by peeling off the protective film is not limited to use in the above-described liquid crystal display device, and can also be applied to optical disks, automobile interior films, lighting films, building material films, and the like.

  The mat film or the protective film is not limited to a single layer configuration, and may have a multilayer configuration of two or more layers as necessary. Examples of the matte film include a two-layer configuration in which a layer made of an acrylic resin and a layer made of a polycarbonate resin are laminated.

<Method for producing laminate>
The method for producing a laminate of the present invention (hereinafter sometimes referred to as the production method of the present invention) is usually a layer (A) comprising a thermoplastic resin composition and a thermoplastic resin composition obtained by melt extrusion of a thermoplastic resin composition and a polyolefin resin. (Hereinafter referred to as layer (A)) and layer (B) made of polyolefin resin (hereinafter also referred to as layer (B)) to obtain a film-like product (1), The film-like material is inserted between the shaping roll and the touch roll so that the layer (B) surface of the shaped product is in contact with the shaping roll, and the layer ( A step (2) in which the mat shape formed on the surface of the shaping roll is transferred to the layer (A) surface in contact with B) to form the mat shape, and the layer (A) surface is used as the mat surface. It is. In the laminate produced by such a production method, the layer (B) made of a polyolefin resin, that is, a protective film is directly laminated on the mat surface of the layer (A) made of the thermoplastic resin composition, that is, the mat surface of the mat film. The layer (A) (matte film) and the layer (B) (protective film) can be peeled off.

  A method for forming a mat shape using a shaping roll is a method by transfer using a metal roll having a mat shape formed on the outer peripheral surface at the time of coextrusion molding. For example, JP 2009-196327 A, JP 2009 The method described in -202382 gazette etc. can be mentioned.

Hereinafter, the production method of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a schematic explanatory view showing one embodiment of the production method of the present invention.
As shown in the figure, in this embodiment, the thermoplastic resin composition and the polyolefin resin charged in the melt extruders 1 and 2 are melt-kneaded and supplied to the distribution block 3 to obtain a desired layer structure. Are distributed in the multi-manifold die 4 (T die) and extruded from the tip of the multi-manifold die 4 as a film.

  In the present embodiment, the layer (A) and the layer (B) are usually laminated and integrated by an intra-die lamination method. Specifically, for example, the thermoplastic resin composition and the polyolefin resin supplied to the distribution block 3 that is a two-type three-layer or two-type two-layer distribution type are layered on both sides of the layer (A) in the distribution block 3. (B) is arranged, or is distributed so that the layer (B) is arranged on one surface of the layer (A), and is laminated in the multi-manifold die 4 to form a three-layer structure or a two-layer structure. Integrated as

The temperature setting of the extruder 1, the extruder 2 and the multi-manifold die 4 may be adjusted as appropriate according to the resin used. A polycarbonate resin is used as the thermoplastic resin contained in the thermoplastic resin composition, and a polyethylene resin is used as the polyolefin resin. When using, it is preferable that the extruder 1 is 220-300 degreeC, the extruder 2 is 210-300 degreeC, and the multi-manifold die 4 is 260-300 degreeC. When a polycarbonate resin is used as the thermoplastic resin and a polypropylene resin is used as the polyolefin resin, the extruder 1 is set to 210 to 290 ° C, the extruder 2 is set to 210 to 280 ° C, and the multi-manifold die 4 is set to 250 to 290 ° C. It is preferable to do this.
If the temperature setting of the extruder 1, the extruder 2 or the multi-manifold die is out of the above range, the polyethylene resin may become a foreign matter due to gelation due to crosslinking. There is a fear.

  In the present embodiment, the multi-manifold method using the distribution block 3 and the multi-manifold die 4 is used, but instead of this, for example, a dual-slot die that is a feed block stacking method or an external die stacking method is used. be able to. Among these, it is preferable to use a multi-manifold system because the thickness accuracy of each layer is more excellent.

  Next, the resin extruded from the multi-manifold die 4 is applied to the touch roll 5 (cooling roll) that is disposed so as to face the forming roll 6 (cooling roll) and face the layer (B) in a substantially horizontal direction. The mat shape is transferred to the surface of the layer (B) by being sandwiched between the mold rolls 6, and the mat shape is also formed on the layer (A) surface in contact with the layer (B) through the layer (B). Transfer is performed to form a laminate. At this time, a mat shape is also formed on the layer (B) surface in contact with the layer (A) surface. Further, the laminate wound around the shaping roll 6 is passed between the shaping roll 6 and the mirror surface roll 7 (cooling roll), and is gently cooled by the mirror surface roll 7 and laminated at a predetermined take-up speed. The body 8 can be obtained.

The touch roll 5 usually has a diameter of about 200 to 1000 mm, and is made of, for example, a rubber roll or a metal elastic roll.
What is necessary is just to adjust the temperature of the touch roll 5 suitably with resin to be used, for example, when using a polycarbonate-type resin for a thermoplastic resin and a polyethylene-type resin for a polyolefin resin, it is 10-160 degreeC normally, Preferably it is 15-150 degreeC. is there. Moreover, when using a polycarbonate-type resin for a thermoplastic resin and a polypropylene-type resin for a polyolefin resin, it is 10-170 degreeC normally, Preferably it is 15-160 degreeC, More preferably, it is 20-150 degreeC.
If the temperature of the touch roll 5 is too low, the resin is rapidly cooled, so that the laminate 8 is likely to remain distorted. If the temperature of the touch roll 5 is too high, the cooling is insufficient. The laminated body 8 may be tightly wound on the roll and wound up.

Examples of the rubber roll include a silicone rubber roll, a fluororubber roll, and a rubber roll mixed with sand to improve releasability.
The hardness of the rubber roll is preferably in the range of A60 ° to A90 ° measured according to JIS K6253. In order to make the hardness of the rubber roll within the above range, for example, it can be arbitrarily performed by adjusting the degree of crosslinking and composition of the rubber constituting the rubber roll.

  As the metal elastic roll, for example, the inside of the roll is made of rubber or a fluid is injected, and the outer peripheral part is made of a metal thin film having flexibility. is there. Specifically, the inside of the roll is composed of a silicone rubber roll, and a cylindrical stainless steel thin film having a thickness of about 0.2 to 1 mm is coated on the outer periphery of the roll, In a case where a fluid such as oil is injected, a cylindrical thin film made of stainless steel having a thickness of about 2 to 5 mm is fixed at the end of the roll, and the fluid is sealed inside.

    As such a touch roll 5, for example, a touch roll 5 made of a metal material or an elastic body and finished in a mirror shape with a plating or the like is used. The surface of the metal thin film or rubber roll of the metal elastic roll is not necessarily smooth, and there is no problem even if a mat shape is provided on the surface in the same manner as the shaping roll 6 described below.

The shaping roll 6 usually has a diameter of about 200 to 1000 mm, and is made of, for example, a metal roll having a mat shape formed on the outer peripheral surface.
What is necessary is just to adjust the temperature of the shaping roll 6 suitably with resin to be used, for example, when using a polycarbonate-type resin for a thermoplastic resin and a polyethylene-type resin for a polyolefin resin, it is 10-80 degreeC normally, Preferably it is 20-60 degreeC. It is. When a polycarbonate resin is used as the thermoplastic resin and a polypropylene resin is used as the polyolefin resin contained in the polyolefin resin, the temperature is usually 10 to 100 ° C, preferably 20 to 80 ° C.
When the temperature of the shaping roll 6 is too low, the resin is rapidly cooled, so that the laminate 8 is likely to remain distorted. When the temperature of the shaping roll 6 is too high, the cooling is insufficient. As a result, the laminate 8 may be in close contact with the roll and wound up.

  Examples of the shaping roll 6 include a drilled roll obtained by shaving a metal lump, a metal roll capable of controlling the temperature of the roll surface through fluid, steam, etc. inside the roll such as a spiral roll having a hollow structure. A roll having a desired mat shape formed on the outer peripheral surface of the roll by sandblasting or engraving can be used.

  Examples of the mat shape formed on the outer peripheral surface of the shaping roll 6 include a mat shape having a specific arithmetic average roughness (Ra) and an uneven shape having a specific pitch and height. By appropriately adjusting the mat shape, the surface roughness of the mat surface of the mat film can be made desired.

The film-like material extruded from the multi-manifold die 4 is a film-like material in which the layer (B) is laminated on both sides of the layer (A), and over the layer (B), the layer (B) and When the mat shape is transferred to the surface of the layer (A) that is in contact, or a film-like product in which the layer (B) is laminated on one surface of the layer (A), and the layer (B) is passed through the layer (B). When the mat shape is formed on the surface (A) in contact with the layer (B), the mat shape of the shaping roll 6 becomes a layer by sandwiching between the touch roll 5 and the shaping roll 6. (A) It is transferred to the surface and formed into a laminate 8. In that case, it extrudes so that the layer (B) surface of a film-form thing may contact the shaping roll 6. FIG.
In addition, when it is a film-like product in which the layer (B) is laminated on both sides of the layer (A) and the mat shape is formed on both sides of the layer (A) through the layer (B), the mat What is necessary is just to pinch | interpose this film-form thing between the cooling rolls formed in the outer peripheral surface.

The laminated body 8 to which the mat shape is transferred is wound around the shaping roll 6 and then taken up and taken up by the take-up roll.
The take-up speed of the take-up roll may be appropriately adjusted depending on the resin used, and is usually 0.5 to 80 m / min, preferably 2 to 60 m / min. If it is slower than 0.5 m / min, it may be disadvantageous in terms of production cost, and if it is faster than 80 m / min, there is a risk that in-line film appearance inspection assuming an optical application will be insufficient.
At this time, the mirror roll 7 may be provided after the shaping roll 6. Thereby, since the laminated body 8 is cooled slowly, the optical distortion of the laminated body 8 can be reduced, and furthermore, the contact time to the shaping roll 6 can be stably secured. The mat shape thus formed can be stably transferred. The mirror roll 7 is not particularly limited, and a normal metal roll conventionally used in extrusion molding can be employed. Specific examples include a drilled roll and a spiral roll. The surface state of the mirror surface roll 7 is preferably a mirror surface.

  The laminate 8 wound around the shaping roll 6 is passed between the shaping roll 6 and the mirror roll 7 so as to be wound around the mirror roll 7. A predetermined gap may be provided between the shaping roll 6 and the mirror roll 7 so as to be in a released state or may be sandwiched between both rolls. In order to cool the laminate 8 more gently, one or a plurality of cooling rolls are provided after the mirror roll 7, and the mat film wound around the mirror roll 7 is sequentially wound around the next cooling roll. May be.

  In addition, in the laminated body in which the mat film or the protective film has a multilayer structure, another melt extruder (not shown) is newly provided in addition to the melt extruders 1 and 2 shown in FIG. A seed 3 layer distribution type block or a 3 type 5 layer distribution type block may be used, and the others may be melt coextrusion molded in the same manner as in the above-described embodiment.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

The structure of the extrusion apparatus used in the following examples and comparative examples is as follows.
Extruder 1: Single screw extruder with vented screw diameter 65mm (manufactured by Toshiba Machine Co., Ltd.)
Extruder 2: Single screw extruder with vented screw diameter 45mm (manufactured by Toshiba Machine Co., Ltd.)
Distribution block 3: 2-type, 2-layer distribution block (manufactured by Toshiba Machine Co., Ltd.)

  Extruders 1 and 2, distribution block 3, multi-manifold die 4, touch roll 5, shaping roll 6, and mirror roll 7 were arranged as shown in FIG. 2, and each roll 5-7 was configured as follows.

<Roll configuration>
The touch roll 5, the shaping roll 6, and the mirror surface roll 7 were configured as follows.
Touch roll 5: Silicone rubber roll shaped roll 6 having an outer diameter of 250 mmφ and a hardness of A70 ° 6: A stainless steel metal roll having an outer diameter of 250 mmφ and a matte shape having an arithmetic average roughness (Ra) of 3.5 μm formed by blasting ( Drilled roll)
Mirror roll 7: Stainless steel metal roll (drilled roll) with an outer diameter of 250 mmφ and a mirror finish

<Measurement method of 50% cumulative particle size of light diffusion particles>
The cumulative 50% particle diameter (D50) of the light diffusing particles was measured by a Fraunhofer diffraction method using laser light source forward scattered light using a Nikkiso Co., Ltd. Microtrac particle size analyzer (model 9220FRA). In measurement, about 0.1 g of light diffusing particles are dispersed in methanol to obtain a dispersion, and after irradiating the dispersion with ultrasonic waves for 5 minutes, the dispersion is put into a sample of the microtrack particle size analyzer. The measurement was performed by putting it in the mouth. The cumulative 50% particle diameter (D50) is a measurement of the particle diameter and volume of all particles, and the volume is accumulated sequentially from the smallest particle diameter, and the accumulated volume is 50% with respect to the total volume of all particles. The particle diameter of the resulting particles.

<Peel strength>
In an atmosphere at 23 ° C., the force required to peel the protective film from the laminate was measured under the conditions of a peel width of 25 mm, a peel angle of 180 °, and a peel speed of 300 mm / min. 25 mm).

Example 1
[Production of laminate master batch]
80 parts by weight of a polycarbonate resin (“Caliver 301-15” manufactured by Sumitomo Dow Co., Ltd.) and 20 parts by weight of crosslinked acrylic polymer particles (“Paraloid EXL5766” manufactured by Rohm and Haas) that are light diffusion particles are mixed. The mixture was melt-kneaded with a twin-screw extruder (not shown) to obtain a master batch pellet of the resin composition. The polycarbonate resin had a refractive index of 1.59, the crosslinked acrylic polymer particles had a refractive index of 1.49, and the absolute value (Δn) of the refractive index difference between them was 0.10. The cumulative 50% particle diameter (D50) of the crosslinked acrylic polymer particles was 0.8 (μm). Further, from the Δn and the D50, Δn × D50 was 0.08.

[Production of laminate]
As the layer (A), 97.0 parts by weight of a polycarbonate-based resin (“Caliver 301-15” manufactured by Sumitomo Dow Co., Ltd.) and 3.0 parts by weight of the master batch pellet were mixed, and the extruder 1 (cylinder temperature: 230). ˜260 ° C., screw rotational speed: 35 rpm, extrusion rate: 50 kg / hour) and melt-kneaded and supplied to the distribution block 3, and as a layer (B), polypropylene resin (“Nobrene W151 manufactured by Sumitomo Chemical Co., Ltd.) Is melt kneaded in an extruder 2 (cylinder temperature: 210 to 260 ° C., screw rotation speed: 30 rpm, extrusion rate 7 kg / hour) and supplied to the distribution block 3, and a layer (B ) / Layer (A) was distributed so as to have a two-layer structure, and then laminated with a multi-manifold die 4 (die temperature: 260 ° C.) to extrude a film.

Next, the film-like material extruded from the multi-manifold die 4 is touched with the touch roll 5 (set temperature: 35 ° C.) and the shaping roll 6 (set temperature: 35) so that the layer (B) is in contact with the shaping roll. C.) to form a laminate. Furthermore, the laminated body wound around the shaping roll 6 is passed between the shaping roll 6 and the mirror roll 7 and wound around the mirror roll 7 (set temperature: 50 ° C.), and the take-up speed is 9 m / min. The layer (B) (protective film) having a thickness of 20 μm is laminated on one surface of the layer (A) (mat film) having a thickness of 130 μm, and the total thickness of 150 μm, in which the surface of the layer (B) is the mat surface. A laminate 8 having a two-layer structure was obtained. In the obtained laminate, no wrinkles were observed in the layer (B) (protective film), and there was no adhesive residue in the layer (A) (matte film) after the protective film was peeled off. The peel strength was 8 g / 25 mm.
Table 1 shows the contents of the polycarbonate resin and the crosslinked acrylic polymer particles in the layer (A) of the obtained laminate.

(Comparative Example 1)
In the layer (A), a laminate was obtained in the same manner as in Example 1 except that the master batch pellet was not used. In the obtained laminate, no wrinkles were found on the protective film, and no adhesive residue was left on the matte film after the protective film was peeled off. The peel strength was 6 g / 25 mm.
Table 1 shows the contents of the polycarbonate resin and the crosslinked acrylic polymer particles in the layer (A) of the obtained laminate.

(Comparative Example 2)
Layer (A) was laminated in the same manner as in Example 1 except that the polycarbonate resin and the master batch pellet were mixed in an amount of 98.5 parts by weight for the polycarbonate resin and 1.5 parts by weight for the master batch pellet. Got the body. In the obtained laminate, no wrinkles were found on the protective film, and no adhesive residue was left on the matte film after the protective film was peeled off. The peel strength was 5 g / 25 mm.
Table 1 shows the contents of the polycarbonate resin and the crosslinked acrylic polymer particles in the layer (A) of the obtained laminate.

(Comparative Example 3)
Layer (A) was laminated in the same manner as in Example 1 except that the mixing amount of the polycarbonate resin and the master batch pellet was 91.0 parts by weight for the polycarbonate resin and 9.0 parts by weight for the master batch pellet. Got the body. In the obtained laminate, no wrinkles were found on the protective film, and no adhesive residue was left on the matte film after the protective film was peeled off. The peel strength was 7 g / 25 mm.
Table 1 shows the contents of the polycarbonate resin and the crosslinked acrylic polymer particles in the layer (A) of the obtained laminate.

  The following evaluation was performed about the layer (A) (mat film) obtained by peeling a layer (B) (protective film) in each obtained laminated body. The results are shown in Table 2.

<Retardation value>
A test piece was cut out from the mat film in a size of 50 mm square, and the retardation value at 590 nm was measured with a micro-area birefringence meter (“KOBRA-CCD / X” manufactured by Oji Scientific Instruments).

<Total light transmittance (Tt) and haze (H)>
Based on JIS K7361-1, the total light transmittance (Tt) of the mat film was measured.
The haze (H) of the matte film was measured according to JIS K7136.

<60 degree specular gloss>
Based on JIS Z8741, the 60 degree specular glossiness of the surface from which the protective film of the matte film was peeled was measured.

<Surface roughness>
The arithmetic average roughness (Ra), the maximum height roughness (Rz) and the average length (RSm) of the contour curve element of the matte surface of the mat film were measured according to JIS B0601-2001 by a surface roughness meter (Mitutoyo ( Measured by “Surf Test SJ-201”).

<Spectral alignment performance>
Using a spectral transmittance measuring machine (UV-4100 spectrophotometer manufactured by Hitachi High-Technologies Corporation), the matte film is placed 300 mm away from the integrating sphere, and the spectral transmittance of light transmitted in the front direction of the matte film Was measured. From the obtained spectral transmittance, the ratio of the amount of transmitted light having a wavelength of 610 nm to the transmitted light having a wavelength of 470 nm was calculated.

<Color of image display>
The VA liquid crystal display device shown in FIG. 1 described above was produced. The resulting mat film was used as the mat film (3) so that the mat surface was on the back side. As the light source (2), a straight fluorescent tube that emits white light including R (red light), G (green light), and B (blue light) was used. A polarized light separating sheet (“DBEF-M” (thickness: 242 μm) manufactured by 3M) (40) is placed on the front surface of the mat film (3) via an adhesive sheet (41) provided with an acrylic adhesive on both sides. Stacked and integrated. In addition, a prism film having a prism triangle with an apex angle of 90 °, a pitch interval between adjacent prisms of 48 μm, and a thickness of 230 μm was used as the condensing optical member (4).
In the manufactured VA type liquid crystal display device, the liquid crystal panel is displayed in a white display state by a pattern generator with the light source turned on, and the image display when the VA type liquid crystal display device is viewed from the front direction and the oblique direction is visually observed. The color of each image display was evaluated. If the image display is an uncolored white image display, the image display color is evaluated as white. If the image display is a reddish white image display, the image display color is evaluated as red. However, when the image display was a white image display with a bluish tint, the color of the image display was evaluated as blue.

DESCRIPTION OF SYMBOLS 1, 2 Melt extruder 3 Distribution block 4 Multi manifold die 5 Touch roll 6 Shaping roll 7 Mirror roll 8 Laminated body

Claims (14)

  A protective film made of a polyolefin resin is directly laminated on a mat surface of a mat film made of a thermoplastic resin composition containing a thermoplastic resin and light diffusing particles, and the content of the light diffusing particles is determined by the thermoplastic resin. And 0.4 to 1.6 parts by weight with respect to 100 parts by weight of the total amount of the light diffusing particles.   When the absolute value of the difference between the refractive index of the thermoplastic resin and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D50 (μm), Δn and D50 are 0.01 ≦ The laminate according to claim 1, satisfying a relational expression of Δn × D50 ≦ 0.25.   The laminate according to claim 1 or 2, wherein the mat film and the protective film are peelable.   2. The thermoplastic resin is at least one selected from the group consisting of a polycarbonate resin, an acrylic resin, a polyester resin, a styrene resin, a methyl methacrylate-styrene resin, an ABS resin, and an AS resin. The laminated body in any one of -3.   The laminate according to any one of claims 1 to 4, wherein the polyolefin resin is at least one selected from the group consisting of a polyethylene resin, a polypropylene resin, and a modified polyolefin resin that is a modified body thereof.   The laminate according to any one of claims 1 to 5, wherein both surfaces of the protective film are mat surfaces.   The laminate according to any one of claims 1 to 6, wherein the mat film has a haze of 90% or less.   The laminate according to any one of claims 1 to 7, wherein the in-plane retardation of the mat film is 30 nm or less, and the 60 ° specular gloss of the surface on which the protective film of the mat film is laminated is 60% or less.   The laminate according to any one of claims 1 to 8, wherein the delamination force between the mat film and the protective film is 5 to 50 g / 25 mm width.   The laminate according to any one of claims 1 to 9, which is produced by melt coextrusion of a thermoplastic resin and a polyolefin resin.   The laminated body in any one of Claims 1-10 in which the mat film formed by peeling a protective film from a laminated body is used for a liquid crystal display device.   The laminate according to claim 11, wherein the mat film is used for protecting a polarization separation sheet in a liquid crystal display device.   A thermoplastic resin and a polyolefin resin are melt-coextruded to obtain a film-like product, which is inserted between the shaping roll and the touch roll so that the surface of the polyolefin resin layer is in contact with the shaping roll. A method for producing a laminate, comprising forming a mat shape on the surface of the layer.   The mat | matte film obtained by peeling a protective film from the laminated body in any one of Claims 1-12.

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