JP2012177900A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate containing an acrylic resin excellent in transparency and elastic organic fine particles.SOLUTION: The laminate comprises a retardation film (D layer) and another layer (E layer) on at least one surface of the retardation film. The retardation film (D layer) contains elastic organic fine particles (G) and an acrylic resin (A). The laminate is obtained by laminating the another layer (E layer) on the retardation film (D layer) having a maximum height Rz(D), with a maximum height Rz(E) of the E layer on an opposite face to the D layer satisfying Rz(D)>Rz(E).

Description

  The present invention relates to a laminate having another layer on at least one side of a retardation film.

  In recent years, the demand for visibility (brighter, easier to see, better contrast, higher viewing angle, etc.) has become stricter as the screen size and usage environment of liquid crystal display devices expand. However, since only the improvement of the liquid crystal cell main body cannot sufficiently satisfy the demand for improving the visibility, it largely depends on the performance improvement of the optical film such as a retardation film.

  Therefore, the optical film such as a retardation film has high transparency, low photoelasticity, heat resistance, light resistance, high surface hardness, high mechanical strength, large retardation, and small wavelength dependence of retardation, Characteristics such as small dependence of the phase difference on the incident angle are required.

  Although acrylic resin is excellent in optical transparency, since the retardation development performance is low, it is difficult to obtain the required retardation even when stretched. Furthermore, while the usage environment of the liquid crystal display device becomes severe, it is difficult to impart sufficient heat resistance to the stretched film of PMMA when the demand for heat resistance of the optical film is increasing. In the case of uniaxial stretching, the flexibility with respect to stretching and bending in the vertical direction is improved, but the flexibility with respect to folding in the direction parallel to the stretching direction is not improved.

  Therefore, a retardation film is developed in which elastic organic fine particles are added to an acrylic resin excellent in heat resistance and retardation development performance.

JP 2008-009378 A

  However, in the retardation film in which elastic organic fine particles are added to the acrylic resin, the haze of the retardation film increases due to the structure and combination of the resin and fine particles, or the film manufacturing process such as extrusion / stretching. Was sometimes seen.

  Specifically, when the dispersibility of the elastic organic fine particles with respect to the acrylic resin is insufficient and the elastic organic fine particles become agglomerates at the wavelength level of visible light, or the refractive index between the acrylic resin and the elastic organic fine particles is sufficiently close. In the absence, haze is known to increase. These phenomena usually originate from an increase in the internal haze of a retardation film composed of an acrylic resin and elastic organic fine particles.

  On the other hand, even when the internal haze of the retardation film composed of acrylic resin and elastic organic fine particles is small, it has been clarified that the haze increases depending on the film production conditions such as extrusion and stretching. In such a case, there has been a problem that the maximum height Rz, which is a parameter of the surface roughness of a retardation film made of an acrylic resin and elastic organic fine particles, greatly increases.

  This invention is made | formed in view of the latter among the said problems, Comprising: It aims at providing the retardation film (laminated body) excellent in transparency containing an acrylic resin and elastic organic fine particles.

  In order to achieve the object, the present inventors have conducted various studies on a film containing an acrylic resin and elastic organic fine particles, and have reached the present invention.

That is, the present invention is a laminate having another layer (E layer) on at least one side of a retardation film (D layer), wherein the retardation film (D layer) comprises elastic organic fine particles (G) and an acrylic resin. It is obtained by laminating another layer (E layer) on a retardation film (D layer) containing (A) and having a maximum height of Rz (D), and is the maximum of the surface of the E layer opposite to the D layer It is a laminate in which the height Rz (E) satisfies the following formula.
Rz (D)> Rz (E)

  According to the present invention, it is possible to provide a laminate having a retardation function, which includes an acrylic resin and elastic organic fine particles, and has excellent optical characteristics such as transparency.

  In the following description, unless otherwise specified, “%” means “% by mass”, “parts” means “parts by mass”, and “A to B” representing a range means “A or more and B or less”. To do. In addition, all of the academic literatures and patent literatures described in this specification are incorporated herein by reference.

[Acrylic resin (A)]
The acrylic resin is a resin having a (meth) acrylic acid ester unit and / or a (meth) acrylic acid unit as a structural unit, and is derived from a (meth) acrylic acid ester or a derivative of (meth) acrylic acid. You may have a unit. The total of the proportion of the structural units derived from the (meth) acrylic acid ester unit, the (meth) acrylic acid unit and the derivative in all the structural units of the acrylic resin is usually 50% by mass or more, preferably 60% by mass. As mentioned above, More preferably, it is 70 mass% or more. In addition, when the main chain has a ring structure that is a derivative of a (meth) acrylic acid ester unit such as a lactone ring structure, the proportion of the (meth) acrylic acid ester unit and the (meth) acrylic acid unit in all the structural units, The sum total with the content rate of a ring structure should just be 50 mass% or more.

  (Meth) acrylic acid ester units are, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, t- (meth) acrylic acid t- Butyl, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, (meth) acryl Dicyclopentanyl acid, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid 2, 3,4,5,6-pentahydroxyhexyl, 2,3,4,5-tetrahydro (meth) acrylic acid Shipenchiru is a structural unit derived from 2- (hydroxymethyl) acrylate, 2- (hydroxymethyl) acrylate, a monomer such as 2- (hydroxyethyl) acrylate.

  The (meth) acrylic acid unit is a structural unit derived from a monomer such as acrylic acid, methacrylic acid, crotonic acid, 2- (hydroxymethyl) acrylic acid, 2- (hydroxyethyl) acrylic acid, and the like.

  The acrylic resin (A) may have two or more of these structural units as a (meth) acrylic acid ester unit and a (meth) acrylic acid unit. The acrylic resin (A) preferably has a methyl methacrylate unit. In this case, the thermal stability of a film obtained by molding the composition containing the acrylic resin (A) and the acrylic resin (A) is improved.

  The acrylic resin (A) is preferably thermoplastic and is preferably amorphous. Moreover, it is preferable that the glass transition temperature (Tg) of an acrylic resin (A) is 110 degreeC or more. Since Tg as a resin can be improved, Tg of acrylic resin (A) is more preferably 115 ° C. or higher, further preferably 120 ° C. or higher, and particularly preferably 130 ° C. or higher. Note that Tg of polymethyl methacrylate (PMMA) which is a typical acrylic resin is about 105 ° C.

  The acrylic resin (A) preferably has a ring structure in the main chain. Since the acrylic resin (A) has a ring structure in the main chain, the Tg of the acrylic resin (A) is increased, and the heat resistance of a molded product obtained from the resin is improved. As described above, a molded product obtained from the acrylic resin (A) having a ring structure in the main chain, such as a film, is suitable for use as an optical member, such as being easily arranged in the vicinity of a heat generating part such as a light source in an image display device. is there.

  Although the kind of ring structure is not specifically limited, For example, it is at least 1 sort (s) chosen from lactone ring structure, glutaric anhydride structure, glutarimide structure, N-substituted maleimide structure, and maleic anhydride structure.

  The following general formula (1) shows a glutaric anhydride structure and a glutarimide structure.

In the general formula (1), R ¹ and R ² are each independently a hydrogen atom or a methyl group, and X ¹ is an oxygen atom or a nitrogen atom. When X ¹ is an oxygen atom, R ³ does not exist, and when X ¹ is a nitrogen atom, R ³ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group. It is.

When X ¹ is an oxygen atom, the ring structure represented by the general formula (1) is a glutaric anhydride structure. The glutaric anhydride structure can be formed, for example, by subjecting a copolymer of (meth) acrylic acid ester and (meth) acrylic acid to dealcoholization cyclocondensation in the molecule.

When X ¹ is a nitrogen atom, the ring structure represented by the general formula (1) is a glutarimide structure. The glutarimide structure can be formed, for example, by imidizing a (meth) acrylic acid ester polymer with an imidizing agent such as methylamine.

  The following general formula (2) shows a maleic anhydride structure and an N-substituted maleimide structure.

In the general formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or a methyl group, and X ² is an oxygen atom or a nitrogen atom. When X ² is an oxygen atom, R ⁶ is not present, and when X ² is a nitrogen atom, R ⁶ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a benzyl group, a cyclopentyl group, a cyclohexyl group. Or it is a phenyl group.

When X ² is an oxygen atom, the ring structure represented by the general formula (2) is a maleic anhydride structure. The maleic anhydride structure can be formed, for example, by copolymerizing maleic anhydride and (meth) acrylic acid ester.

When X ² is a nitrogen atom, the ring structure represented by the general formula (2) is an N-substituted maleimide structure. The N-substituted maleimide structure can be formed, for example, by polymerizing an N-substituted maleimide such as phenylmaleimide and a (meth) acrylic acid ester.

  In each method for forming the ring structure exemplified in the description of the general formulas (1) and (2), all polymers used for forming each ring structure have a (meth) acrylate unit as a single unit. The resin obtained by this method is an acrylic resin.

  The lactone ring structure that the acrylic resin (A) may have in the main chain is not particularly limited, and may be, for example, a 4- to 8-membered ring. Alternatively, a 6-membered ring is preferable, and a 6-membered ring is more preferable. The lactone ring structure which is a 6-membered ring is, for example, the structure disclosed in Japanese Patent Application Laid-Open No. 2004-168882, but the lactone ring structure is high due to the high polymerization yield of the precursor and the cyclization condensation reaction of the precursor. A structure represented by the following general formula (3) is preferable because an acrylic resin (A) having a ring content can be obtained and a polymer having a methyl methacrylate unit as a constituent unit can be used as a precursor.

In the general formula (3), R ⁷ , R ⁸ and R ⁹ are each independently a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom.

  The organic residue in the general formula (3) is, for example, an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, or a propyl group, and an organic residue having 1 to 20 carbon atoms such as an ethenyl group or propenyl group. An aromatic hydrocarbon group having 1 to 20 carbon atoms such as a saturated aliphatic hydrocarbon group, a phenyl group, and a naphthyl group, and the alkyl group, the unsaturated aliphatic hydrocarbon group, and the aromatic hydrocarbon group are One or more hydrogen atoms may be substituted with at least one group selected from a hydroxyl group, a carboxyl group, an ether group, and an ester group.

  Although the content rate of this ring structure except the lactone ring structure in an acrylic resin (A) is not specifically limited, For example, it is 5-90 mass%, Preferably it is 10-70 mass%, More preferably, this is 10-60 mass %, More preferably 10 to 50%.

  When the acrylic resin (A) has a lactone ring structure in the main chain, the content of the lactone ring structure in the resin is not particularly limited, but is, for example, 5 to 90% by mass, preferably 10 to 80% by mass. More preferably, it is 10-70 mass%, More preferably, it is 20-60 mass%.

  When the content of the ring structure in the acrylic resin (A) becomes transiently small, the heat resistance of the film may be lowered, and the solvent resistance and surface hardness may be insufficient. On the other hand, when the content rate increases transiently, the moldability and mechanical properties of the film deteriorate.

  The acrylic resin (A) having a ring structure in the main chain can be produced by a known method. An acrylic resin whose ring structure is a glutaric anhydride structure or a glutarimide structure can be produced, for example, by the method described in WO2007 / 26659 or WO2005 / 108438. An acrylic resin whose ring structure is a maleic anhydride structure or an N-substituted maleimide structure can be produced, for example, by the method described in JP-A-57-153008 and JP-A-2007-31537. An acrylic resin whose ring structure is a lactone ring structure can be produced by, for example, the method described in JP-A-2006-96960, JP-A-2006-171464, JP-A-2007-63541, or WO2009 / 084663. .

  The acrylic resin (A) may have a structural unit other than the (meth) acrylic acid ester unit and the (meth) acrylic acid unit. Examples of such a structural unit include styrene, vinyltoluene, and α-methyl. Styrene, α-hydroxymethylstyrene, α-hydroxyethylstyrene, acrylonitrile, methacrylonitrile, methallyl alcohol, allyl alcohol, ethylene, propylene, 4-methyl-1-pentene, vinyl acetate, 2-hydroxymethyl-1-butene , Methyl vinyl ketone, N-vinyl pyrrolidone, vinyl anthracene, dibenzofulvene, N-vinyl carbazole, vinyl pyridine, vinyl imidazole and vinyl thiophene. The acrylic resin (A) may have two or more of these structural units.

  The acrylic resin (A) may have a structural unit having an effect of giving negative intrinsic birefringence to the resin. In this case, the degree of freedom in controlling birefringence and wavelength dispersion in the film made of the acrylic resin (A) is improved, and the use application of the retardation film (laminate) in the present invention is expanded.

  Intrinsic birefringence refers to the orientation axis from the refractive index n1 of light in a direction parallel to the direction (orientation axis) in which molecular chains are oriented in a layer (for example, a sheet or film) in which resin molecular chains are uniaxially oriented. A value obtained by subtracting the refractive index n2 of the light in the direction perpendicular to (i.e., "n1-n2"). The positive / negative of the intrinsic birefringence of the acrylic resin (A) itself is determined by the balance between the action of the structural unit with respect to the intrinsic birefringence and the action of the other structural unit of the acrylic resin (A).

  An example of a structural unit having an effect of giving negative intrinsic birefringence to the acrylic resin (A) is a structural unit derived from a monomer of styrene or N-vinylcarbazole.

  The weight average molecular weight of an acrylic resin (A) is the range of 1000-500000, for example, Preferably it is the range of 5000-300000, More preferably, it is the range of 10,000-250,000, More preferably, it is the range of 50000-200000. is there.

  The acrylic resin (A) may contain other resins as long as the effects of the present invention are not impaired. The content of other resins is preferably 0 to 50% by mass, more preferably 0 to 25% by mass, and still more preferably 0 to 10% by mass.

  Examples of other resin components include olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, and poly (4-methyl-1-pentene); halogen-containing polymers such as vinyl chloride and chlorinated vinyl resins; Acrylic polymers such as polymethyl methacrylate; styrene polymers such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer; polyethylene terephthalate, polybutylene terephthalate, Polyesters such as polyethylene naphthalate; biodegradable polyesters such as polylactic acid and polybutylene succinate; cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate Cellulose polymers such as nylon; polyamides such as nylon 6, nylon 66, nylon 610; polyacetal; polyphenylene oxide; polyphenylene sulfide; polyether ether ketone; polyether nitrile; polysulfone; And so on.

  From the viewpoint of compatibility, a styrene-acrylonitrile copolymer is preferable. Acrylic resins having a ring structure in the main chain often have positive intrinsic birefringence, but styrene-acrylonitrile-based copolymers have negative intrinsic birefringence. A film or a negative retardation film can be obtained.

  In addition, a carbazole group-containing copolymer is also a preferred form from the viewpoint of controlling the wavelength dispersion of the retardation. The carbazole group-containing copolymer is not particularly limited, but from the viewpoint of compatibility with the acrylic resin (A), an N-vinylcarbazole / (meth) acrylic acid ester copolymer, an N-vinylcarbazole / acrylonitrile copolymer, N-vinylcarbazole / (meth) acrylic acid ester / acrylonitrile copolymer and the like. By adjusting the amount of the carbazole group-containing copolymer added to the acrylic resin having a ring structure in the main chain, it is possible to obtain a low retardation film or a retardation film having a wavelength dispersion of a retardation having a reverse wavelength.

  The acrylic resin (A) may have an ultraviolet absorbing ability as long as the heat resistance, physical properties, and optical properties are not impaired. Specifically, a method using an ultraviolet-absorbing monomer and / or an ultraviolet-stable monomer as a monomer component when producing the acrylic resin (A), an ultraviolet absorber and / or an ultraviolet stabilizer There exists a method of mix | blending with an acrylic resin (A) (A). Moreover, as long as there is no trouble in the optical film containing an acrylic resin (A), you may use these methods together. In order to maintain the ultraviolet absorbing function, it is preferable to use an ultraviolet absorbing monomer and an ultraviolet stabilizing monomer in combination, or to use an ultraviolet absorber and an ultraviolet stabilizer in combination. It is also preferable to use an ultraviolet absorber and / or an ultraviolet stabilizer in combination with the ultraviolet absorbing monomer and / or the ultraviolet stabilizing monomer.

  Examples of the ultraviolet absorbing monomer include benzotriazole compounds, benzophenone compounds or triazine compounds and acrylic monomers having a polymerizable unsaturated group. Examples of benzotriazole compounds include 2- [2′-hydroxy-5 ′-(meth) acryloyloxymethylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxyethyl. Phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxypropylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxyhexyl Phenyl] -2H-benzotriazole, 2- [2′-hydroxy-3′-tert-butyl-5 ′-(meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′ -(Β- (Meth) acryloyloxyethoxy) -3′-tert-butyl Enyl] -5-tert-butyl-2H-benzotriazole, 2- [2′-hydroxy-3′-methacrylaminomethyl-5 ′-(1 ″, 1 ″, 3 ″, 3 ″ -tetramethyl) butylphenyl ] -2H-benzotriazole and the like can be used. Examples of the benzophenone compounds include 2-hydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [2- (meth) acryloyloxy] butoxybenzophenone, 2,2 ′. -Dihydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [2- (meth) acryloyloxy] ethoxy-4 '-(2-hydroxyethoxy) benzophenone, and the like can be used. . Examples of the triazine compound include 4-diphenyl-6- [2-hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine, 2,4-bis (2-methylphenyl) -6- [2-Hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine, 2,4-bis (2-methoxyphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy)]- An s-triazine or the like can be used. When using such an ultraviolet-absorbing monomer, it is preferably copolymerized in an amount of 0.1 to 25% by weight, more preferably 1 to 15% by weight of all monomers. . If the content is small, the contribution to improving the weather resistance is low, and if the content is too large, the hot water resistance and solvent resistance may decrease or yellowing may occur.

  As the UV-stable monomer, one in which a polymerizable unsaturated group is bonded to a hindered amine compound can be used. Specific examples include 4- (meth) acryloyloxy-2,2,6,6. -Tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- ( (Meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2 , 2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meta Acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl- 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine and the like can be mentioned. When such an ultraviolet-stable monomer is used, it is preferably copolymerized in an amount of 0.1 to 25% by weight, more preferably 1 to 15% by weight of all monomers. . If the content is small, the contribution to improving the weather resistance is low, and if the content is too large, the hot water resistance and solvent resistance may decrease or yellowing may occur.

  Examples of the ultraviolet absorber include benzophenone compounds, salicinate compounds, benzoate compounds, triazole compounds, and triazine compounds. Examples of the benzophenone compounds include 2,4-dihydroxybenzophenone, 4-n-octyloxy-2-hydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-n-octyl. Examples thereof include oxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 1,4-bis (4-benzoyl-3-hydroxyphenone) -butane and the like. Examples of the silicate compound include pt-butylphenyl silicate. Examples of the benzoate compound include 2,4-di-t-butylphenyl-3 ', 5'-di-t-butyl-4'-hydroxybenzoate. Examples of triazole compounds include 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (3 , 5-Di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol, 2-benzotriazol-2-yl-4,6-di-tert-butylphenol, 2- [5-chloro (2H) -benzotriazole- 2-yl] -4-methyl-6-tert-butylphenol, 2- (2H-benzotriazol-2-yl) -4,6-di-tert-butylphenol, 2- 2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl) -4-methyl-6- (3,4) , 5,6-tetrahydrophthalimidylmethyl) phenol, methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate / polyethylene glycol 300 reaction product 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2- Hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 3- (2H-benzotriazol-2-yl ) -5- (1,1-dimethylethyl) -4-hydroxy -C7-9 side chain and straight chain alkyl esters. Furthermore, as triazine compounds, 2-mono (hydroxyphenyl) -1,3,5-triazine compounds, 2,4-bis (hydroxyphenyl) -1,3,5-triazine compounds, 2,4,6- And tris (hydroxyphenyl) -1,3,5-triazine compounds, specifically, 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-ethoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-propoxyphenyl) -1,3,5- Triazine, 2,4-diphenyl- (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxy) Enyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2- Hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl -6- (2-hydroxy-4-benzyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyethoxy) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-butoxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3-5-triazine, 2,4,6-tris (2-hydroxy-4- Me Xylphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-ethoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4) -Propoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy) -4-butoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine, 2,4,6-tris ( 2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine, 2,4 6-Tris (2-hydroxy-4-benzyloxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-ethoxyethoxyphenyl) -1,3,5-triazine, 2,4 , 6-Tris (2-hydroxy-4-butoxyethoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-propoxyethoxyphenyl) -1,3,5-triazine 2,4,6-tris (2-hydroxy-4-methoxycarbonylpropyloxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-ethoxycarbonylethyloxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4- (1- (2-ethoxyhexyloxy) -1-oxopropane-2- Ruoxy) phenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-methoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-ethoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-propoxyphenyl) -1,3,5 Triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-butoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4) -Butoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-hexyloxyphenyl) -1,3,5-triazine, 2,4,6- Tris (2-hydroxy 3-methyl-4-octyloxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-dodecyloxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-benzyloxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-ethoxy) Ethoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-butoxyethoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-propoxyethoxyphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-methoxycarbonylpropyloxy) Ciphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-ethoxycarbonylethyloxyphenyl) -1,3,5-triazine, 2,4,6- And tris (2-hydroxy-3-methyl-4- (1- (2-ethoxyhexyloxy) -1-oxopropan-2-yloxy) phenyl) -1,3,5-triazine. Among them, 2,4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4- (3-alkyloxy-2) is highly compatible with acrylic resins and has excellent absorption characteristics. -Hydroxypropyloxy) -5-α-cumylphenyl] -s-triazine skeleton (alkyloxy; long-chain alkyloxy groups such as octyloxy, nonyloxy, decyloxy, etc.). Further, an ultraviolet absorber having a 2,4,6-tris (hydroxyphenyl) -1,3,5-triazine skeleton is preferably used, and 2,4,6-tris (2-hydroxy-4-long chain alkyloxy) is used. Group-substituted phenyl) -1,3,5-triazine skeleton and 2,4,6-tris (2-hydroxy-3-alkyl-4-long-chain alkyloxy group-substituted phenyl) -1,3,5-triazine skeleton The ultraviolet absorber having is a particularly preferred triazine-based ultraviolet absorber.

  These can be used alone or in combination of two or more. Moreover, it is also preferable to use together the method of copolymerizing this ultraviolet absorptive monomer with an ultraviolet absorber. Although the compounding quantity of a ultraviolet-stable monomer ultraviolet absorber is not specifically limited, It is preferable that it is 0.01-25 mass% in the film containing an acrylic resin, More preferably, it is 0.05-10 mass%. . If the amount added is too small, the contribution to improving weather resistance is low, and if it is too large, the mechanical strength may be lowered or yellowing may be caused.

  The acrylic resin (A) may contain other additives. The content of other additives in the acrylic resin (A) is preferably 0 to 5% by mass, more preferably 0 to 2% by mass, and still more preferably 0 to 0.5% by mass. Examples of other additives include hindered phenol-based, phosphorus-based and sulfur-based antioxidants; light-resistant stabilizers, weather-resistant stabilizers, heat-stabilizers, and other stabilizers; reinforcing materials such as glass fibers and carbon fibers. Near infrared absorbers; flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, antimony oxide; antistatic agents such as anionic, cationic and nonionic surfactants; inorganic pigments, organic pigments, dyes, etc. Colorants; organic fillers and inorganic fillers; resin modifiers; plasticizers; antiblocking agents.

  A known antioxidant can be used as the antioxidant. Examples of phenolic antioxidants include n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, n-octadecyl-3- (3,5-di-t-butyl). -4-hydroxyphenyl) acetate, n-octadecyl-3,5-di-t-butyl-4-hydroxybenzoate, n-hexyl-3,5-di-t-butyl-4-hydroxyphenylbenzoate, n-dodecyl 3,5-di-t-butyl-4-hydroxyphenylbenzoate, neododecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, dodecyl-β- (3,5-di- t-butyl-4-hydroxyphenyl) propionate, ethyl-α- (4-hydroxy-3,5-di-t-butylphenyl) isobutyrate Octadecyl-α- (4-hydroxy-3,5-di-t-butylphenyl) isobutyrate, octadecyl-α- (4-hydroxy-3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2- (n-octylthio) ethyl-3,5-di-t-butyl-4-hydroxybenzoate, 2- (n-octylthio) ethyl-3,5-di-t-butyl-4-hydroxyphenyl acetate, 2 -(N-octadecylthio) ethyl-3,5-di-t-butyl-4-hydroxyphenyl acetate, 2- (n-octadecylthio) ethyl-3,5-di-t-butyl-4-hydroxybenzoate, 2- (2-hydroxyethylthio) ethyl-3,5-di-t-butyl-4-hydroxybenzoate, diethyl glycol bis- (3,5 -Di-t-butyl-4-hydroxy-phenyl) propionate, 2- (n-octadecylthio) ethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, stearamide-N, N -Bis- [ethylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], n-butylimino-N, N-bis- [ethylene-3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionate], 2- (2-stearoyloxyethylthio) ethyl-3,5-di-t-butyl-4-hydroxybenzoate, 2- (2-stearoyloxyethylthio) ethyl- 7- (3-Methyl-5-tert-butyl-4-hydroxyphenyl) heptanoate, 1,2-propylene glycol bis- [3- (3,5 Di-t-butyl-4-hydroxyphenyl) propionate], ethylene glycol bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], neopentyl glycol bis- [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate], ethylene glycol bis- (3,5-di-t-butyl-4-hydroxyphenyl acetate), glycerin-1-n-octadecanoate- 2,3-bis- (3,5-di-t-butyl-4-hydroxyphenyl acetate), pentaerythritol tetrakis- [3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) Propionate], 1,1,1-trimethylolethanetris- [3- (3,5-di-tert-butyl-4-hydroxypheny ) Propionate], sorbitol hexa- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2-hydroxyethyl-7- (3-methyl-5-tert-butyl-4-hydroxy Phenyl) propionate, 2-stearoyloxyethyl-7- (3-methyl-5-tert-butyl-4-hydroxyphenyl) heptanoate, 1,6-n-hexanediol bis-[(3 ', 5'-di- t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis- (3,5-di-t-butyl-4-hydroxyhydrocinnamate), 3,9-bis [1,1-dimethyl-2- [ [beta]-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] 2,4,8,10-tetrao Saspiro [5,5] -undecane, 2,4-di-t-amyl-6- [1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate and 2-t-butyl -6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate.

  Examples of the thioether-based antioxidant include pentaerythrityl tetrakis (3-laurylthiopropionate), dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl. -3,3'-thiodipropionate.

  Examples of phosphorus antioxidants include tris (2,4-di-t-butylphenyl) phosphite, 2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo [d. , F] [1,3,2] dioxaphosphin-6-yl] oxy] -N, N-bis [2-[[2,4,8,10-tetrakis (1,1 dimethylethyl) dibenzo [D, f] [1,3,2] dioxaphosphin-6-yl] oxy] -ethyl] ethanamine, diphenyltridecyl phosphite, triphenyl phosphite, 2,2-methylenebis (4,6- Di-t-butylphenyl) octyl phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite DOO, cyclic neopentanetetraylbis (2,6-di -t- butyl-4-methylphenyl) phosphite and the like.

  The anti-blocking agent may be liquid, solid, or particulate as long as it exhibits the slipperiness of the film, such as an anti-blocking agent, an anti-blocking agent, a slipping agent, a lubricant, and a release agent. Particulate anti-blocking agent fine particles are preferred, and organic crosslinked polymer fine particles and inorganic fine particles can be used. The average particle diameter of the anti-blocking agent fine particles is preferably 0.01 to 30 μm, more preferably 0.05 to 10 μm, and still more preferably 0.1 to 5 μm. When the average particle size is less than 0.01 μm, the slipperiness is not sufficiently expressed, and when it exceeds 30 μm, fish eyes and the like are generated, the transparency of the film is not maintained, and the appearance may be poor. .

  The organic crosslinked polymer fine particles are not particularly limited, but monofunctional monomers such as methyl methacrylate and polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, allyl (meth) acrylate, and di (meth) acrylic. (Meth) acrylic crosslinked fine particles obtained by suspension polymerization of ethylene glycol acid (see Japanese Patent No. 4034157) and styrene monomers such as styrene, α-methylstyrene, divinylbenzene in the suspension polymerization (meth) Styrene- (meth) acrylic crosslinked particles obtained by copolymerization with acrylic monomers, or emulsion polymerization, soap-free emulsion polymerization, miniemulsion polymerization, dispersion polymerization, or seed polymerization of (meth) acrylic monomers or styrene monomers. (Meth) acrylic crosslinked particles and Down - (meth) acrylic crosslinked fine particles and the like.

  The inorganic fine particles are not particularly limited, and examples thereof include fine particles of fused silica, synthetic silica, zeolite, alumina, titania, and complex oxides thereof. The organic-inorganic composite fine particles are organic-inorganic composite fine particles composed of an organic portion and an inorganic portion. The proportion of the inorganic part is not particularly limited, but is preferably 0.5 to 90% by mass, more preferably 1 to 70% by mass in terms of inorganic oxide, for example, with respect to the mass of the organic / inorganic composite fine particles. %, More preferably in the range of 2 to 60% by mass. Inorganic oxide conversion indicating the proportion of the inorganic portion is expressed as a mass percentage obtained by measuring the mass before and after firing the organic / inorganic composite fine particles in an oxidizing atmosphere such as air at a high temperature (for example, 1000 ° C.). It is. If the proportion of the inorganic part of the organic-inorganic composite fine particles is less than the above range in terms of inorganic oxide, the organic-inorganic composite fine particles may become soft, which may be disadvantageous for the expression of slipperiness. If it exceeds the upper limit, it may be too hard and scratches may be caused on the film surface.

Such organic-inorganic composite fine particles are not particularly limited, but preferably an organic polymer skeleton described in JP-A-8-81561 and organic silicon in which a silicon atom is directly chemically bonded to at least one carbon atom in the organic polymer skeleton. An organic-inorganic composite fine particle containing 25 wt% or more of SiO ₂ constituting the polysiloxane skeleton, or a (meth) acryloxy group described in JP-A No. 2003-183337 Organic inorganic composite fine particles in which a vinyl polymer is contained in the structure of the inorganic fine particles made of polysiloxane fine particles having the above.

  The refractive index of the fine particles is preferably close to the refractive index of the acrylic resin in order to improve the transparency of the film. Specifically, the refractive index ratio is preferably 0.98 to 1.02, more preferably 0.99 to 1.01.

  The content of the antiblocking agent with respect to the acrylic resin is preferably 0.005 to 3% by mass, more preferably 0.01 to 2% by mass, and still more preferably 0.01 to 1% by mass. When the content of the anti-blocking agent is less than 0.005% by mass, sufficient slipperiness cannot be obtained, and when it is more than 3% by mass, fish eyes and the like occur frequently on the film (laminate), and the appearance Becomes defective.

[Elastic organic fine particles (G)]
The elastic organic fine particles (G) (hereinafter sometimes simply referred to as “organic fine particles”) are not particularly limited, and known organic fine particles can be used. From the viewpoint of imparting a high retardation, conjugated dienes can be used. It is preferable to use a conjugated diene monomer structural unit constructed by polymerizing monomers as an essential component. Moreover, it is also possible to be an acrylic rubber containing a structural unit derived from an acrylate monomer.

  The ratio of the elastic organic fine particles (G) to the acrylic resin (A) is preferably in the range of 5 to 100% by weight and in the range of 10 to 80% by weight with respect to 100 parts by weight of the acrylic resin (A). It is more preferable that it is in the range of 15 to 50% by weight. If the content ratio of the elastic organic fine particles is less than 5% by weight, desired flexibility may not be obtained. Also, if the content of elastic organic fine particles exceeds 100% by weight, the transparency may decrease due to aggregation of the elastic organic fine particles, or by-products of foreign matter will increase, making it impossible to use as a film (laminate). There is.

  The elastic organic fine particles (G) more preferably have a multilayer structure, and more specifically, elastic organic fine particles having a so-called core-shell structure having a core portion and a shell portion are more preferable. The multilayer structure may have any number of layers, but two or three layers are more preferable from the viewpoint of ease of synthesis.

  The elastic organic fine particles (G) having a core / shell structure have a conjugated diene monomer unit structure or acrylic rubber in the central portion (core), and an acrylic resin (A) in the portion (shell) surrounding the central portion. It is preferable to have a structure having high compatibility with (A). The shell may have two or more layers, but the outermost layer preferably has a structure having high compatibility with the acrylic resin (A). Since the compatibility between the acrylic resin (A) and the shell is high, the dispersibility of the elastic organic fine particles in the acrylic resin (A) is improved, the transparency of the film (laminate) is improved, and the elastic organic fine particles are aggregated. It is possible to further suppress the by-product of the foreign matter caused by the like. Thereby, the filtration process at the time of retardation film (laminated body) shaping | molding can be performed in a short time.

  As a shell part in the elastic organic fine particles (G), a monomer composition composed of acrylonitrile (hereinafter sometimes referred to as “AN”) and styrene (hereinafter sometimes referred to as “St”) is used. A structure constructed by polymerization and a structure constructed by polymerizing a monomer composition mainly composed of a methacrylic acid ester such as methyl methacrylate are preferred in terms of high compatibility with the acrylic resin (A). . When the acrylic resin (A) is a lactone ring-containing polymer, a structure constructed by polymerizing a monomer composition composed of at least AN and St is preferable in terms of compatibility.

  The glass transition temperature of the core part is more preferably in the range of −140 to −40 ° C., further preferably in the range of −130 to −55 ° C., and particularly preferably in the range of −125 to −70 ° C. Is within. When the glass transition temperature of the soft polymer layer is less than −40 ° C., the flexibility can be improved with a small amount of addition.

  The shell part is not particularly limited as long as the shell part has a highly compatible structure with the acrylic resin (A). As a structure which comprises the shell part which has a structure with high compatibility with an acrylic resin (A), when an acrylic resin is a lactone ring containing polymer mentioned later, for example, 2- (hydroxymethyl) methyl acrylate (following , And may be described as MHMA) and a structure constructed by polymerizing a monomer composition consisting of methyl methacrylate (hereinafter sometimes referred to as MMA) (hereinafter referred to as MHMA / MMA structure). In some cases), a structure constructed by polymerizing a monomer composition composed of cyclohexyl methacrylate (hereinafter sometimes referred to as CHMA) and MMA (hereinafter sometimes referred to as CHMA / MMA structure). ), A structure constructed by polymerizing a monomer composition composed of benzyl methacrylate (hereinafter sometimes referred to as BzMA) and MMA (hereinafter referred to as BzMA / MMA). ), A structure constructed by polymerizing a monomer composition consisting of 2-hydroxyethyl methacrylate (hereinafter sometimes referred to as HEMA) and MMA (hereinafter referred to as HEMA / MMA structure), a structure constructed by polymerizing a monomer composition composed of acrylonitrile and styrene (hereinafter sometimes referred to as AN / St structure), and the like.

  When the shell has an AN / St structure, the ratio of AN to St is preferably in the range of 5:95 to 50:50, and more preferably in the range of 10:90 to 40:60. preferable. Within this range, the compatibility with the lactone ring-containing polymer is good, and the elastic organic fine particles can be uniformly dispersed in the acrylic resin. In addition to AN and St, (meth) acrylic acid esters such as acrylate and methyl methacrylate, styrene, vinyl toluene, α-methyl styrene, α-hydroxymethyl styrene, α-hydroxyethyl styrene, acrylonitrile, methacrylonitrile , Methallyl alcohol, allyl alcohol, ethylene, propylene, 4-methyl-1-pentene, vinyl acetate, 2-hydroxymethyl-1-butene, methyl vinyl ketone, N-vinyl pyrrolidone, N-vinyl carbazole, etc. It is also possible to copolymerize.

  The ratio of the core part to the shell part is preferably in the range of 20:80 to 80:20, more preferably in the range of 40:60 to 60:40, as the core: shell ratio by weight. When the core part is less than 20% by weight, the bending resistance of the film formed from the elastic organic fine particles obtained tends to deteriorate, and when it exceeds 80% by weight, the hardness and formability of the film tend to decrease.

  The shell part may or may not have a cross-linked structure, but the shell part is more preferably not having a cross-linked structure.

  Further, in the elastic organic fine particles (G), although not particularly limited, it is more preferable that the core portion has a crosslinked structure.

  The average particle diameter of the elastic organic fine particles (G) is preferably in the range of 0.01 to 1 μm, more preferably in the range of 0.03 to 0.5 μm, and 0.05 to 0.3 μm. It is particularly preferable that the value falls within the range. When the average particle diameter is less than 0.01 μm, there is a tendency that sufficient flexibility cannot be obtained when a film is produced. When the average particle diameter exceeds 1 μm, the filter is used in a filtration process during film production. There is a tendency that elastic organic fine particles are easily clogged. The particle diameter of the elastic organic fine particles can be measured using a commercially available particle size distribution measuring device (for example, a particle size distribution measuring device (Submicron Particle Sizer NICOMP380) manufactured by NICOMP).

  From the viewpoint of imparting a high retardation, the core preferably contains a conjugated diene monomer structural unit constructed by polymerizing conjugated diene monomer units as an essential component. When the core has a conjugated diene monomer structural unit as an essential component, it can be obtained by polymerizing a monomer composition containing a conjugated diene monomer. Examples of the conjugated diene monomer include 1,3-butadiene (hereinafter sometimes simply referred to as “butadiene”), isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2 -Chloro-1,3-butadiene, myrcene and the like may be mentioned, and these may be used alone or in combination of two or more. As the conjugated diene monomer, butadiene and / or isoprene are more preferable.

  Components other than those described above in the monomer composition are not particularly limited, but include silicone components such as dimethylsiloxane and phenylmethylsiloxane; styrene components such as styrene and α-methylstyrene; nitriles such as acrylonitrile and methacrylonitrile. Component: Urethane component; Ethylene component; Propylene component; Isobutene component, alkyl acrylate component such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, benzyl acrylate, and the like.

  Moreover, the polyfunctional crosslinkable monomer and the polyfunctional graft monomer may be included, for example, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, polyethylene glycol di (meth). ) Acrylate, divinylbenzene, allyl (meth) acrylate, allyl maleate, allyl fumarate, diallyl fumarate, triallyl cyanurate and the like. These can be used alone or in combination of two or more.

  The content ratio of the conjugated diene monomer in the monomer composition is preferably 25% by weight or more, more preferably 50% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more. That is, it is more preferable that the soft polymer layer of the elastic organic fine particles (G) contains 25% by weight or more of conjugated diene monomer structural units. The soft polymer layer of the elastic organic fine particles (G) further preferably contains 50% by weight or more of conjugated diene monomer structural units, and contains 70% by weight or more of conjugated diene monomer structural units. It is particularly preferable that 90% by weight or more of the conjugated diene monomer structural unit is contained.

  When the core part is an acrylic rubber containing a structural unit derived from an acrylate monomer, the acrylate monomer includes methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic Examples thereof include t-butyl acid, 2-ethylhexyl acrylate, cyclohexyl acrylate, benzyl acrylate, hydroxyethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, and butoxyethyl acrylate.

  The content of the structural unit derived from the acrylate monomer in the acrylic rubber is not particularly limited as long as it is 50% by mass or more, and if it is less than 50% by mass, the flexibility may be insufficiently improved. is there.

  The acrylic rubber may contain a structural unit derived from a vinyl monomer copolymerizable with an acrylate monomer. Such structural units include, for example, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, hydroxyethyl methacrylate, methacrylate esters such as 2-ethylhexyl methacrylate, butadiene, isoprene, 1,3-pentadiene, 2 , 3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, myrcene, styrene, vinyltoluene, α-methylstyrene, α-hydroxymethylstyrene, α-hydroxyethylstyrene, acrylonitrile, methacrylonitrile , Methallyl alcohol, allyl alcohol, ethylene, propylene, 4-methyl-1-pentene, vinyl acetate, 2-hydroxymethyl-1-butene, methyl vinyl ketone, N-vinyl pyrrolidone, N-vinyl carbazole, etc. Derived from A structural unit.

  The acrylic rubber preferably has a crosslinked structure, for example, by polymerizing an acrylate monomer composition containing a polyfunctional compound having two or more nonconjugated double bonds per molecule. Obtainable. Examples of the polyfunctional compound include allyl methacrylate, allyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyl acrylate, 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, triallyl cyanurate, Allyl isocyanurate, diallyl phthalate, diallyl malate, divinyl adipate, divinyl benzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, trimethylolpropane Trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetramethacrylate Rate, tetramethylolmethane tetraacrylate, dipropylene glycol dimethacrylate and dipropylene glycol diacrylate and the like, which may be used only one kind or in combination of two or more.

  The production method of the elastic organic fine particles (G) is not particularly limited, and the monomer composition described above is obtained by a conventionally known emulsion polymerization method, emulsion-suspension polymerization method, suspension polymerization method, bulk polymerization method or solution polymerization method. Elastic organic fine particles (G) can be produced by polymerizing the product in one or more stages. Among these, the emulsion polymerization method is more preferable.

  When the elastic organic fine particles are produced by emulsion polymerization, the elastic organic fine particles are aggregated by salting out or reprecipitation of the polymer solution after the emulsion polymerization, and then filtered and washed. After washing, the elastic organic fine particles are dried and mixed with an acrylic resin to produce a composition that is a raw material for the retardation film (laminate). After washing, without drying the elastic organic fine particles, the obtained elastic organic fine particle cake is redispersed in an organic solvent such as MIBK (methyl isobutyl ketone), and the acrylic resin is dissolved or redispersed in the redispersed liquid. A composition that becomes a raw material for a retardation film (laminate) by mixing a liquid and an acrylic resin solution (a solution obtained by dissolving an acrylic resin with an organic solvent) and then devolatilizing water and / or the organic solvent. Can be manufactured.

  As the polymerization initiator during the polymerization of the elastic organic fine particles (G), conventionally known initiators such as organic peroxides, inorganic peroxides, and azo compounds can be used. Specifically, for example, t-butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, succinic acid peroxide, peroxymaleic acid t-butyl ester, cumene hydroper Organic peroxides such as oxide and benzoyl peroxide, inorganic peroxides such as potassium persulfate and sodium persulfate, oil solubility such as azobis (2-methylpropionamidine) dihydrochloride, azobisisobutyronitrile An initiator etc. are mentioned. These may be used alone or in combination of two or more.

  The polymerization initiator is combined with a reducing agent such as sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, hydroxyacetone acid, ferrous sulfate, ferrous sulfate and disodium ethylenediaminetetraacetate. It may also be used as a normal redox type initiator.

The organic peroxide can be added by a known addition method such as a method of adding it to the polymerization system as it is, a method of adding it mixed with a monomer, a method of adding it dispersed in an emulsifier aqueous solution, etc. From the viewpoint of transparency, a method of adding a mixture to a monomer or a method of adding it by dispersing in an aqueous emulsifier solution is preferable.
The organic peroxide is an inorganic reducing agent such as divalent iron salt and / or formaldehyde sulfoxylate soda, reducing sugar, ascorbic acid and the like from the viewpoint of polymerization stability and particle size control. It is preferable to use it as a redox initiator combined with an organic reducing agent.

  The surfactant used for the emulsion polymerization is not particularly limited, and a conventionally known surfactant for emulsion polymerization can be used. Specifically, for example, anionic surfactants such as sodium alkyl sulfonate, sodium alkyl benzene sulfonate, sodium dioctyl sulfosuccinate, sodium lauryl sulfate, sodium fatty acid, alkylphenols, aliphatic alcohols, etc. And nonionic surfactants such as reaction products of olefins with propylene oxide and ethylene oxide. These surfactants may be used alone or in combination of two or more. Furthermore, if necessary, a cationic surfactant such as an alkylamine salt may be used.

The resulting latex of elastic organic fine particles can be separated and recovered by ordinary coagulation, washing and drying operations, or by treatment by spray drying, freeze drying or the like.
The elastic organic fine particles described above may be included in the retardation film only in one type, or in two or more types.

[Phase difference film (D layer)]
The retardation film (D layer) contains elastic organic fine particles (G) and an acrylic resin (A).

  The ratio of the elastic organic fine particles (G) in the retardation film (D layer) is preferably in the range of 3 to 50% by mass, more preferably in the range of 4 to 40% by mass, and 5 to 30% by mass. More preferably, it is in the range of%. If the content of the elastic organic fine particles (G) is less than 3% by mass, desired flexibility may not be obtained. On the other hand, if the content of the elastic organic fine particles (G) exceeds 50% by mass, the transparency may decrease due to aggregation of the rubbery polymer, or foreign substances may be generated as by-products, making it impossible to use as a retardation film. There is a case.

  Further, the acrylic resin (A) ratio in the retardation film (D layer) is preferably in the range of 50 to 97% by mass, more preferably in the range of 60 to 96% by mass, and 70 to 95% by mass. More preferably, it is in the range of%. When the acrylic resin (A) is less than 50% by mass, the optical properties may be deteriorated. Moreover, when the content rate of a rubber-like polymer exceeds 50 mass%, desired flexibility may not be obtained.

  The retardation film (D layer) preferably has a lower birefringence as the wavelength becomes shorter in the visible light region. The wavelength dispersibility of the retardation film can be evaluated by measuring the retardation of the retardation film at different wavelengths. For example, the retardation value at a measurement wavelength of 590 nm is used as a reference (R0), and the wavelength dispersion at other wavelengths is evaluated. When the ratio to the phase difference R (R / R0) is less than 1 at 590 nm or less and more than 1 at a wavelength exceeding 590 nm, the birefringence decreases as the wavelength decreases in the visible light region, That is, it becomes reverse wavelength dispersion. In the present invention, when the ratio of the in-plane retardation measured at 447 nm and 550 nm is D, D is preferably 0.6 or more and less than 1, more preferably 0.7 or more and less than 0.97.

The “phase difference” is also called a retardation value. The in-plane retardation Re here is Re = (nx−ny) × d
The thickness direction retardation (Rth) is
Rth = [(nx + ny) / 2−nz] × d
Defined. Nx is the refractive index in the slow axis direction in the film plane, ny is the refractive index in the direction perpendicular to nx in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness (nm). . The slow axis direction is a direction in which the refractive index in the film plane is maximum. Further, a material having a large refractive index in the stretching direction is said to have positive birefringence, and a material having a large refractive index in the direction perpendicular to the stretching direction in the film plane is said to have negative birefringence.

  When the retardation film (D layer) is a uniaxially stretched film, the in-plane retardation Re at a wavelength of 590 nm is preferably 50 to 300 nm and the thickness direction retardation Rth is preferably 10 to 300 nm. When the thickness is about 100 μm, the in-plane retardation Re at a wavelength of 590 nm is preferably 50 to 500 nm, and the thickness direction retardation Rth is preferably 10 to 500 nm.

  When the retardation film (D layer) is used as a λ / 2 plate, Re at 590 nm is preferably 200 to 350 nm, more preferably 240 to 300 nm, particularly preferably 260 to 280 nm, and most preferably It is 265-275 nm.

  When the retardation film (D layer) is used as a λ / 4 plate, Re at 590 nm is preferably 100 to 200 nm, more preferably 120 to 160 nm, particularly preferably 130 to 150 nm, and most preferably 135-145 nm.

  In the case where the retardation film (D layer) is a biaxially stretched film, a biaxially stretched film having an in-plane retardation Re at 590 nm of 20 to 70 nm and a retardation value Rth of 70 to 400 nm is also a preferred embodiment. When the thickness is about 100 μm, the in-plane retardation Re at a wavelength of 590 nm is preferably 20 to 110 nm, and the thickness direction retardation Rth is preferably 70 to 800 nm.

  The “in-plane retardation at a wavelength of 590 nm per 100 μm thickness” is a value at d = 100 × 1000 nm in the above formula for obtaining the in-plane retardation Re. The “thickness direction retardation at a wavelength of 590 nm per thickness of 100 μm” is a value at d = 100 × 1000 nm in the above equation for obtaining the thickness direction retardation (Rth).

  The thickness of the retardation film (D layer) is, for example, 1 μm or more and less than 1000 μm, preferably 5 μm or more and less than 350 μm, more preferably 10 μm or more and less than 100 μm. When the thickness is less than 1 μm, the strength as a film may be insufficient, and breakage or the like is likely to occur during post-processing.

  The retardation film (D layer) has a high light transmittance. When the film has a thickness of 100 μm, the total light transmittance is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.

  The haze of the retardation film (D layer) is preferably 0.5 to 12%, more preferably 0.5 to 10%, and still more preferably 0.5 to 8%. When the haze is smaller than 0.5%, the haze of the laminate formed by the retardation film (D layer) and another layer (E layer) may be higher than that of the retardation film (D layer). Moreover, when haze is larger than 12%, even if another layer (E layer) is laminated | stacked, there exists a possibility that the haze of a laminated body may not become small enough.

  The internal haze of the retardation film (D layer) is preferably 1% or less.

  The retardation film (D layer) is less colored, and the b value per 250 μm thickness is preferably 0.5 or less, more preferably 0.3 or less.

  The retardation film (D layer) preferably has a glass transition temperature of 110 ° C to 200 ° C. More preferably, it is 115 degreeC-200 degreeC, More preferably, it is 120 degreeC-200 degreeC, Especially preferably, it is 125 degreeC-190 degreeC, Most preferably, it is 130 degreeC-180 degreeC. When the temperature is less than 110 ° C., the heat resistance is insufficient with respect to the harsh use environment, and the film may be deformed to easily cause unevenness in retardation, which is not preferable. Moreover, when it exceeds 200 degreeC, the moldability for obtaining a film may be bad, or the flexibility of a film may fall significantly.

  The retardation film (D layer) is not particularly limited, and can be produced by a known production method such as a solution casting method or a melt casting method. A stretched film or a laminated film may be used.

  When a film is to be obtained using the solution casting method (solution casting method), a resin with acrylic resin (A) and elastic organic fine particles (G), and if necessary, other polymers and other additives It can be obtained by stirring and mixing (composition) in a good solvent to obtain a uniform mixed solution, casting on a support film or drum and pre-drying until it has self-supporting properties, then peeling off from the support film or drum and drying. . Solvents used in the solution casting method (solution casting method) include, for example, chlorinated solvents such as chloroform and dichloromethane; aromatic solvents such as toluene, xylene, benzene, and mixed solvents thereof; methanol, ethanol, and isopropanol And alcohol solvents such as n-butanol and 2-butanol; methyl cellosolve, ethyl cellosolve, butyl cellosolve, dimethylformamide, dimethyl sulfoxide, dioxane, cyclohexanone, tetrahydrofuran, acetone, ethyl acetate, and diethyl ether. These solvents may be used alone or in combination of two or more. Examples of the apparatus for performing the solution casting method (solution casting method) include a drum casting machine and a belt casting machine.

  As a specific example of the melt extrusion method, the kneader used for extrusion kneading is not particularly limited. For example, a known kneader such as a single screw extruder, a twin screw extruder, or a pressure kneader is used. Can be used. In addition, acrylic resin (A), elastic organic fine particles (G), and additives as necessary are added, and after pre-blending with a mixer such as an omni mixer, the resulting mixture is extruded and kneaded from a kneader. Also good.

  Examples of the melt extrusion method include a T-die method and an inflation method, and the molding temperature at that time is preferably 200 to 350 ° C., more preferably 250 to 300 ° C., further preferably 255 to 300 ° C., particularly Preferably it is 260 to 300 degreeC.

  When the T-die method is used, a resin film wound into a roll can be obtained by attaching a T-die to the tip of the extruder and winding the film extruded from the T-die. At this time, it is also possible to control the temperature and speed of winding and to stretch (uniaxial stretching) in the extrusion direction of the film. Further, the film may be stretched in a direction perpendicular to the extrusion direction, and sequential biaxial stretching or simultaneous biaxial stretching may be performed.

  When an extruder is used for extrusion molding, the type is not particularly limited and may be uniaxial, biaxial, or multiaxial, but its L / D value is (L is the value of the extruder) In order to sufficiently plasticize the thermoplastic resin to obtain a good kneaded state, the length of the cylinder, D is the cylinder inner diameter) is preferably 10 or more and 100 or less, more preferably 15 or more and 80 or less, and still more preferably Is 20 or more and 60 or less. When the L / D value is less than 10, the thermoplastic resin cannot be sufficiently plasticized and a good kneaded state may not be obtained. On the other hand, if the L / D value exceeds 100, the resin may be thermally decomposed due to excessive heat generation from the thermoplastic resin.

  In this case, the set temperature of the cylinder is preferably 200 ° C. or higher and 350 ° C. or lower, more preferably 250 ° C. or higher and 300 ° C. or lower. If setting temperature is less than 200 degreeC, the melt viscosity of a thermoplastic resin will become high too much, and the productivity of a resin film will fall. On the other hand, when the set temperature exceeds 350 ° C., the resin in the thermoplastic resin may be thermally decomposed.

  When an extruder is used for extrusion molding, the shape is not particularly limited, but the extruder preferably has one or more open vent portions. By using such an extruder, the decomposition gas can be sucked from the open vent portion, and the amount of volatile components remaining in the obtained resin film can be reduced. In order to suck the decomposition gas from the open vent portion, for example, the open vent portion may be in a reduced pressure state, and the degree of pressure reduction is preferably in the range of 931 to 1.3 hPa as the pressure of the open vent portion, 798 A range of ˜13.3 hPa is more preferable. When the pressure in the open vent is higher than 931 hPa, volatile components or monomer components generated by the decomposition of the resin are likely to remain in the thermoplastic resin. On the other hand, it is industrially difficult to keep the pressure of the open vent part lower than 1.3 hPa.

  Moreover, when melt-extruding, a method of forming a film by bringing at least one surface of the obtained film-like material into contact with a roll or a belt is preferable in that a film having good surface properties can be obtained. Furthermore, from the viewpoint of improving the surface smoothness and surface gloss of the film, a method of forming a film by bringing both surfaces of a film-like product obtained by melt extrusion molding the above mixture into contact with the roll surface or belt surface is preferred.

  In addition, although the said roll may be called a "touch roll" or a "cooling roll", the term "roll" in this specification includes both these meanings.

  Here, the temperature of the film-like material when both surfaces of the film-like material are first brought into contact with the roll or belt surface is a temperature equal to or higher than the glass transition temperature of the film-like material, preferably about 20 ° C. above the glass transition temperature. This is a high temperature.

  As the material of the roll or belt surface, metal is preferable because of good cooling efficiency and easy to obtain a film having excellent smoothness. Specific examples include stainless steel and steel. In the case of using steel, the surface thereof may be subjected to a treatment such as chrome plating. Further, the roll is preferably one having a mirror surface.

  The temperature of the roll or belt surface at the time of contacting with the film-like material is not particularly limited, but is preferably maintained at a constant temperature from the viewpoint that it can be easily formed into a film.

  The number of the rolls used is not particularly limited, but it is desirable to use 3 to 4 rolls and adjust the film thickness and surface state in multiple stages.

  The contact with the roll surface or the belt surface may be made stepwise by contacting one surface of the film-like material and then contacting the other surface, but it is preferable to contact both surfaces simultaneously.

  The film thus obtained has sufficient thickness accuracy and surface smoothness, but in order to further improve the thickness accuracy and surface smoothness, both surfaces or one surface thereof are in contact with the roll surface or belt surface. You may heat in the state made to cool, and it may cool in the state which contacted the roll surface or the belt surface.

  Furthermore, when a film-like material extruded from a T die or the like is sandwiched between two rolls and cooled to form a film, one of the two rolls is a rigid metal roll having a smooth surface, The other is preferably a flexible roll provided with an elastically deformable metal elastic outer cylinder having a smooth surface.

  By sandwiching a film-like material extruded from a T-die or the like with a rigid roll and a flexible roll and cooling to form a film, fine irregularities on the surface and die lines are corrected, and the surface is smooth. A film with little thickness unevenness can be obtained.

  In addition, in this embodiment, it is more preferable to pre-dry film raw materials, such as acrylic resin to be used, before forming into a film. The preliminary drying is performed using, for example, a hot air dryer or the like in the form of pellets or the like. Pre-drying is very useful because it can prevent foaming of the extruded resin.

  Moreover, it is preferable to supply the film raw material (thermoplastic resin) heated and melted in the extruder to the T die through a gear pump or a filter. The use of the gear pump is very useful because it has a high effect of improving the uniformity of the extrusion amount of the resin and reducing thickness unevenness. The use of the filter is useful for removing a foreign substance in the resin and obtaining a film having a defect-free appearance.

  In addition, at the time of filtration with a polymer filter, a thermoplastic resin will be in a high temperature molten state. For this reason, when passing through the polymer filter, the thermoplastic resin deteriorates, and gas components and colored deterioration products formed by the deterioration flow into the resin (composition), and the resulting film is perforated and flows. Defects such as patterns and flow lines may be observed. This defect is particularly apt to be observed during the continuous forming of a film. For this reason, when molding a thermoplastic resin filtered with a polymer filter, the molding temperature decreases the melt viscosity of the thermoplastic resin and shortens the residence time of the thermoplastic resin in the polymer filter, for example, 255. It is -350 degreeC and 260-320 degreeC is preferable.

  The configuration of the polymer filter is not particularly limited, but a polymer filter in which a large number of leaf disk filters are arranged in a housing can be suitably used. The filter material of the leaf disk type filter may be any of a type in which a metal fiber nonwoven fabric is sintered, a type in which metal powder is sintered, a type in which several metal meshes are laminated, or a hybrid type in which they are combined. The sintered type is most preferred.

  The filtration accuracy by the polymer filter is not particularly limited, but is usually 15 μm or less, preferably 10 μm or less, more preferably 5 μm or less. When the filtration accuracy is 1 μm or less, the residence time of the thermoplastic resin becomes longer, so that the thermal deterioration of the resin increases, and the productivity of the resin film decreases. On the other hand, if the filtration accuracy exceeds 15 μm, it is difficult to remove foreign substances in the thermoplastic resin.

  The filtration area with respect to the resin processing amount per hour in the polymer filter is not particularly limited, and can be appropriately set according to the processing amount of the thermoplastic resin. The filtration area is, for example, 0.001 to 0.15 m2 / (kg / hour).

  The shape of the polymer filter is not particularly limited. For example, an inner flow type having a plurality of resin flow ports and a resin flow path in the center pole; an inner peripheral surface of the leaf disk filter at a plurality of vertices or faces And an external flow type having a resin flow path on the outer surface of the center pole. In particular, it is preferable to use an external flow type in which the resin stays are small.

  Although there is no restriction | limiting in particular in the residence time of the thermoplastic resin in a polymer filter, Preferably it is 20 minutes or less, More preferably, it is 10 minutes or less, More preferably, it is 5 minutes or less. Moreover, the filter inlet pressure and the filter outlet pressure at the time of filtration are, for example, 3 to 15 MPa and 0.3 to 10 MPa, respectively, and the pressure loss (pressure difference between the filter inlet pressure and the outlet pressure) is 1 MPa to 15 MPa. A range is preferred. When the pressure loss is 1 MPa or less, the flow path through which the thermoplastic resin passes through the filter tends to be biased, and the quality of the obtained resin film tends to deteriorate. On the other hand, when the pressure loss exceeds 15 MPa, the polymer filter is easily damaged.

  What is necessary is just to set suitably the temperature of the thermoplastic resin introduce | transduced into a polymer filter according to the melt viscosity, for example, it is 250-300 degreeC, Preferably it is 255-300 degreeC, More preferably, it is 260-300 degreeC. is there.

  The specific process of obtaining a resin film with few foreign substances and colored substances by filtration using a polymer filter is not particularly limited. For example, (1) a process of forming and filtering a thermoplastic resin in a clean environment, and subsequently molding the thermoplastic resin in a clean environment; (2) clean the thermoplastic resin having foreign matter or colored matter A process of molding a thermoplastic resin in a clean environment after filtration in an environment; (3) a process of molding a thermoplastic resin having foreign matters or colored substances at the same time as a filtration treatment in a clean environment; Etc. You may perform the filtration process of the thermoplastic resin by a polymer filter in multiple times for each process.

  When filtering the thermoplastic resin with the polymer filter, it is preferable to install a gear pump between the extruder and the polymer filter to stabilize the pressure of the thermoplastic resin in the filter.

  The unstretched film obtained by extrusion may be stretched as necessary. The method of uniaxially or biaxially stretching the obtained optical film is not particularly limited, and a known method may be followed. Uniaxial stretching is typically free-end uniaxial stretching in which the change in the width direction of the film is free. Fixed-end uniaxial stretching is also possible in which the change in the width direction of the film is fixed. The biaxial stretching is typically sequential biaxial stretching in which transverse stretching is performed after longitudinal stretching, but simultaneous biaxial stretching in which longitudinal and transverse stretching is simultaneously performed can also be suitably used. Furthermore, it is also possible to stretch in the oblique direction with respect to stretching in the thickness direction or film roll. The stretching method, the stretching temperature, and the stretching ratio can be appropriately selected according to the target optical characteristics and mechanical characteristics.

  The specific method of the longitudinal stretching step in the production method of the present invention is not limited, and for example, any method of oven stretching and roll stretching may be used.

  The oven vertical stretching machine includes a transport roll and an oven on each of the oven inlet side and the outlet side. The original film is stretched in the flow direction (longitudinal direction) by making a peripheral speed difference between the transport roll on the oven entrance side and the transport roll on the exit side. The oven has a function of heating the original film to a temperature at which it can be stretched. Depending on the stretching conditions, a heat treatment effect can be imparted to the original film after stretching by an oven.

  The stretching temperature in the oven longitudinal stretching is preferably (Tg-10) ° C to (Tg + 50) ° C, more preferably (Tg-5) ° C to (Tg + 40) ° C, based on the glass transition temperature (Tg) of the original film. Yes, and more preferably (Tg) ° C. to (Tg + 30) ° C. If it is stretched below (Tg-10) ° C., the original film may be broken. If the temperature exceeds (Tg + 50) ° C., the sag of the original film increases, and there is a risk of rubbing or breaking with the apparatus.

  On the other hand, the roll longitudinal stretching machine is composed of a number of rolls or nip rolls (heated rolls) that can be heated and a number of rolls or nip rolls (cooling rolls) that can be cooled. The original film is preheated to the stretching temperature while continuously contacting a number of heating rolls, stretched by a short section (stretching section) nip roll provided between the heating roll and the cooling roll, and then cooled by the cooling roll. The In order to stabilize the stretching temperature, an auxiliary heating device may be provided in the stretching section.

  The temperature of the heating roll is the set temperature of the roll. The stretching temperature and stretching ratio of the original film can be appropriately adjusted using as an index the mechanical strength, surface properties and thickness accuracy of the original film obtained after the longitudinal stretching. In stretching, the original film is preferably heated to (Tg-10) ° C. to (Tg + 20) ° C. by a heating roll based on the glass transition temperature (Tg) of the film, and further provided in the stretching section. It is more preferable to heat to (Tg) ° C. to (Tg + 30) ° C. or less with an auxiliary heating device. When the heating of the original film with a heating roll is lower than (Tg-10) ° C., problems in the process such as tearing or breaking of the original film are likely to occur. When it is higher than (Tg + 20) ° C., a trouble that the original film adheres to the roll is likely to occur. In addition, when the heating in the auxiliary heating device is lower than (Tg) ° C., wrinkles are likely to occur in the original film, and it is easy to cause problems in the process such as tearing and cracking of the film. If it is high, mechanical properties such as elongation, tensile strength, and flexibility of the finally obtained optical film are not improved, and secondary workability may be deteriorated. The total number of heating rolls is preferably 5 or more. When the number is less than 5, the heating effect is reduced, so that the original film cannot be sufficiently warmed. A method of increasing the roll diameter in order to enhance the heating effect is not preferable because the thermal expansion of the film due to heating cannot be released and wrinkles and breakage due to wrinkles are likely to occur. As the auxiliary heating device provided in the stretching section, a conventionally known method can be used, and any heating method selected from an IR heater, a ceramic heater, and a hot air heater is preferable from the viewpoint of the introduction cost of the device.

  Further, when the distance between the center of the heating roll (low speed roll) and the center of the cooling roll (high speed roll) in the stretching section is defined as the stretching section length A and the original film width before longitudinal stretching is B, the ratio A / B is 0. .05 or more and 0.5 or less is preferable. If it is smaller than 0.05, the length of the stretched section becomes too short with respect to the width of the original film, and the diameter of the high-speed roll needs to be reduced. In this case, since the strength of the stretching apparatus is insufficient such as bending of the roll, uniform stretching cannot be performed. When the ratio is larger than 0.5, the influence of neck-in in the longitudinal stretching is exerted to the film center portion, which is disadvantageous for the retardation in the width direction and the uniformity of the thickness. The ratio is more preferably 0.1 or more and 0.45 or less.

  The transverse stretching step is a step of stretching the original film in the width direction. The apparatus used for the transverse stretching may be either a grip type or a pin type, but the grip type is more preferable because the original film is difficult to tear. The grip-type tenter stretching machine includes a grip traveling device for transverse stretching and an oven. The grip traveling device grips and conveys the lateral end of the original film with the grip, and at the same time, opens the guide rail of the grip traveling device to widen the distance between the left and right rows of grips, thereby stretching the film. A simultaneous biaxial stretching machine having a grip expansion / contraction function in the longitudinal direction of the film may also be used. The oven has a function of heating (preheating) the original film to a temperature at which it can be stretched. Depending on the stretching conditions, a heat treatment effect can be imparted to the film after transverse stretching by an oven. The film exiting the oven is then cooled. In any case, the stretching temperature of the film is preferably (Tg-10) ° C to (Tg + 50) ° C, more preferably (Tg-5) ° C, based on the glass transition temperature (Tg) of the thermoplastic resin film. ~ (Tg + 30) ° C. Moreover, it is preferable not to extend | stretch until extending | stretching temperature reaches the glass transition temperature of an original film. Thereby, it can be set as a phase difference film with small thickness nonuniformity and phase difference nonuniformity. The transverse stretching step refers to a series of steps of heating (preheating), stretching and cooling. In the transverse stretching step, stretching of the original film in the width direction is performed, and in that case, stretching of the original film in the flow direction can also be performed.

  The draw ratio in the transverse stretching step is an area ratio, preferably in the range of 1.1 to 25 times, more preferably in the range of 1.2 to 10 times, and still more preferably in the range of 1.3 to 5 times. If it is smaller than 1.1 times, it is not preferable because it does not lead to the development of retardation performance accompanying to stretching and the improvement of toughness. If it is larger than 25 times, the effect of increasing the draw ratio is not recognized.

  The draw ratio for each of the machine direction and the transverse direction is preferably in the range of 1.05 to 10 times, more preferably in the range of 1.1 to 5 times, and still more preferably in the range of 1.2 to 3 times. . If it is less than 1.05 times, the strength of the film may be insufficient, or a desired retardation value may not be obtained. When it is larger than 10 times, the effect of only increasing the draw ratio is not recognized, and the film may be broken during the drawing, which is not preferable.

The stretching speed is preferably in the range of 10-20000% / min, more preferably in the range of 100-10000% / min. If it is slower than 10% / min, it takes time to obtain a sufficient draw ratio, and the production cost is increased, which is not preferable. If it is faster than 20000% / min, the film may be broken, which is not preferable.
[Laminate]
The laminate of the present invention has another layer (E layer) on at least one side of the retardation film (D layer), and another layer (D layer) having a maximum height of Rz (D) ( E layer), and the maximum height Rz (E) of the surface of the E layer on the side opposite to the D layer satisfies the formula “Rz (D)> Rz (E)”. It is preferable that “Rz (D)> Rz (E) +1.5 μm” is satisfied.
By satisfying Rz (D)> Rz (E), the transparency of the laminate is improved. Moreover, it is preferable that the haze of the laminated body of this invention is 2% or less, More preferably, it is 1% or less.

  The maximum height Rz is a parameter for surface roughness, and was obtained in accordance with the provisions of JIS B 0601-2001. As a measuring apparatus, a laser microscope VK-9700 (manufactured by Keyence) was used.

In the laminate of the present invention, for example, when Rz (D) is 1.0 μm to 2.5 μm, Rz (E) is preferably 0.4 μm or more and less than 1.0 μm. If within this range,
Laminating another layer (E layer) is preferable because the surface roughness of the laminate can be reduced, haze can be reduced, and the transparency of the laminate can be ensured.

  Further, in the laminate of the present invention, in the retardation film (D layer), the ratio Re (447) / Re (590) of the in-plane retardation Re (447) and Re (590) with respect to light having wavelengths of 447 and 590 nm. Is preferably 0.75 or more and 0.97 or less. Here, Re (447) and Re (590) can be measured by the method described in Examples described later. Within such a range, a retardation film having excellent optical properties can be obtained.

  In the laminate of the present invention, the film thickness at which Re (590) of the retardation film (D layer) is 140 nm is preferably 110 μm or less. Conventionally, as described above, even when the internal haze of a retardation film made of an acrylic resin and elastic organic fine particles is small, there is a problem that the haze increases depending on film production conditions such as extrusion and stretching. In order to solve this haze increase problem, the present inventors have further reduced the “surface roughness” and “haze” when the stretching conditions are further changed (for example, stretching at a high temperature and a low magnification). However, it has been found that the retardation of the retardation film is insufficient and the film thickness may increase. In this case, it is not preferable from the viewpoint of thinning. However, according to the present laminate, a sufficient phase difference can be ensured even if the film thickness is 110 μm or less, so that a thin film can be achieved.

  The laminate of the present invention may have another layer (E layer) on at least one side of the retardation film (D layer), and may have an E layer only on one side of the D layer. May have an E layer. The E layer is preferably an easily adhesive layer. In another preferred embodiment, the E layer is an adhesive layer. Furthermore, it has E layer on both surfaces of D layer, and one of E layers may be an easily bonding layer, and the other may be an adhesion layer.

  In the laminate of the present invention, the surface of the retardation film (D layer) forming another layer (E layer) is subjected to surface treatment (for example, corona discharge treatment, plasma treatment, ozone spraying, ultraviolet irradiation, flame treatment, chemical treatment). (Chemical treatment).

  The method of forming another layer (E layer) is not particularly limited, but an aqueous or solvent primer or adhesive is applied to the surface of the retardation film (D layer) to form a coating film of the dispersion. It is possible to form.

  In the coating process, a known method can be applied as a coating method. Specifically, for example, a bar coating method, a roll coating method, a gravure coating method, a rod coating method, a slot orifice coating method, a curtain coating method, or a fountain coating method may be used.

  The thickness of the coating film formed in the coating process can be appropriately adjusted according to the thickness required when the coating film becomes an easy-adhesion layer.

  When forming a laminated body, the process from film formation (extrusion, stretching) to finally obtaining a laminated body can be performed continuously. In this case, the step of applying to the surface of the film and the step of stretching the applied film in a heated atmosphere can be performed continuously. In this specification, the coating process continuously performed with the process of extending | stretching the film which apply | coated the dispersion is called in-line coating. It is preferable to continuously perform a step of stretching an unstretched film to form a uniaxially stretched film, a step of coating the surface of the film, and a step of stretching the coated film in a heated atmosphere.

  When the E layer is an easy-adhesion layer, the easy-adhesion layer is not particularly limited, and known easy-adhesion layers are used, and polyurethane-based, polyester-based, cellulose-based, silicone-based, polyethyleneimine-based, and amino acids in the molecule. Resins containing groups are used.

  The number average molecular weight of the resin used for the easy adhesion layer is preferably 5,000 to 600,000, more preferably 10,000 to 400,000.

  The easy adhesion layer is preferably a urethane resin. The urethane resin is not particularly limited, and is typically a resin obtained by reacting a polyol and a polyisocyanate. Any polyol having two or more hydroxyl groups in the molecule can be adopted as the polyol. The polyol is, for example, a polyacryl polyol, a polyester polyol, or a polyether polyol. Two or more polyols may be combined.

  The polyacryl polyol is typically a copolymer of a (meth) acrylic acid ester monomer and a monomer having a hydroxyl group. The (meth) acrylic acid ester monomer is, for example, methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, or cyclohexyl (meth) acrylate. Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (Meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 4-hydroxybutyl and (meth) acrylic acid 2-hydroxypentyl; (meth) acrylic acid monoesters of polyhydric alcohols such as glycerin and trimethylolpropane; N -Methylol (meth) acrylamide.

  The polyacryl polyol may be a copolymer with further other monomers. The other monomer is not limited as long as it can be copolymerized with the (meth) acrylic acid ester monomer and the monomer having a hydroxyl group. Such other monomers include, for example, unsaturated monocarboxylic acids such as (meth) acrylic acid; unsaturated dicarboxylic acids such as maleic acid and anhydrides and mono- or diesters thereof; unsaturated nitriles such as (meth) acrylonitrile Unsaturated amides such as (meth) acrylamide and N-methylol (meth) acrylamide; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl ethers such as methyl vinyl ether; α-olefins such as ethylene and propylene; Halogenated α, β-unsaturated aliphatic monomers such as vinyl chloride and vinylidene chloride; α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene.

  The polyester polyol is typically obtained by reacting a polybasic acid component with a polyol component. Examples of the polybasic acid component include orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and tetrahydrophthalic acid. Aromatic dicarboxylic acids; oxalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, tartaric acid, alkylsuccinic acid, Aliphatic dicarboxylic acids such as linolenic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid; hexahydrophthalic acid, tetrahydrophthalic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc. Alicyclic dicarbo Acid; or their acid anhydrides are reactive derivative such as an alkyl ester, acid halide.

  Examples of the polyol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, and 1,6-hexanediol. 1,8-octanediol, 1,10-decanediol, 1-methyl-1,3-butylene glycol, 2-methyl-1,3-butylene glycol, 1-methyl-1,4-pentylene glycol, 2 -Methyl-1,4-pentylene glycol, 1,2-dimethyl-neopentyl glycol, 2,3-dimethyl-neopentyl glycol, 1-methyl-1,5-pentylene glycol, 2-methyl-1,5 -Pentylene glycol, 3-methyl-1,5-pentylene glycol, 1,2-dimethylbutylene Coal, 1,3-dimethylbutylene glycol, 2,3-dimethylbutylene glycol, 1,4-dimethylbutylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F.

  The polyether polyol is typically obtained by adding an alkylene oxide to a polyhydric alcohol by ring-opening polymerization. The polyhydric alcohol is, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, or trimethylolpropane. The alkylene oxide is, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran.

  Examples of the polyisocyanate include tetramethylene diisocyanate, dodecamethylene diisocyanate, 1,4-butane diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, Aliphatic diisocyanates such as 2-methylpentane-1,5-diisocyanate and 3-methylpentane-1,5-diisocyanate; isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4'-cyclohexylmethane diisocyanate, 1,4-cyclohexane Alicyclic diisodies such as diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane Anate; tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1 , 5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate and other aromatic diisocyanates; dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, α, α, α, α-tetramethylxylylene An aromatic aliphatic diisocyanate such as range isocyanate.

  The urethane resin preferably has a carboxyl group. By having a carboxyl group, the performance (adhesiveness) of the easy adhesion layer is improved. The urethane resin having a carboxyl group can be obtained, for example, by reacting a chain extender having a free carboxyl group in addition to a polyol and a polyisocyanate. Examples of the chain extender having a free carboxyl group are dihydroxycarboxylic acid and dihydroxysuccinic acid. The dihydroxycarboxylic acid is a dialkylol alkanoic acid such as dimethylol alkanoic acid (for example, dimethylol acetic acid, dimethylol butanoic acid, dimethylol propionic acid, dimethylol butyric acid, dimethylol pentanoic acid).

  The acid value of the urethane resin is preferably 10 or more, more preferably 10 to 50, and particularly preferably 20 to 45. In these cases, the performance of the easy adhesion layer is further improved.

The urethane resin may be obtained by reaction with other polyols or other chain extenders in addition to the components described above. Other polyols include, for example, sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, trimethylolethane , Trimethylolpropane, pentaerythritol, and other polyols having three or more hydroxyl groups. Other chain extenders include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 1,6- Glycols such as hexanediol and propylene glycol; Aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, 1,4-butanediamine, and aminoethylethanolamine; Fats such as isophorone diamine and 4,4'-dicyclohexylmethanediamine Cyclic diamines; aromatic diamines such as xylylenediamine and tolylenediamine.

  The urethane resin can be formed by applying a known method. This method is, for example, a one-shot method in which each component is reacted at once, or a multi-stage method in which the components are reacted stepwise. The urethane resin having a carboxyl group is preferably formed by a multistage method since the introduction of the carboxyl group is easy. The catalyst used for forming the urethane resin is not particularly limited.

  The urethane resin is preferably an aqueous dispersion. Compared to organic solvent-based dispersions, water-based dispersions have less environmental impact and are excellent in workability. The aqueous dispersion may contain a neutralizing agent. In this case, the stability of the urethane resin in the aqueous dispersion medium is improved. Examples of the neutralizing agent include ammonia, N-methylmorpholine, triethylamine, dimethylethanolamine, methyldiethanolamine, triethanolamine, morpholine, tripropylamine, ethanolamine, triisopropanolamine, 2-amino-2-methyl-1- Propanol.

  When the urethane resin dispersion is water-based, it is preferable to use an organic solvent that is inert to the polyisocyanate and is compatible with water when the urethane resin is formed. Examples of organic solvents include ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ether solvents such as dioxane, tetrahydrofuran, and propylene glycol monomethyl ether. is there.

  The content of the urethane resin in the urethane resin dispersion is preferably 1.5 to 15% by weight, and more preferably 2 to 10% by weight. When the content ratio is within these ranges, the coating property of the dispersion is high.

  The urethane resin dispersion preferably contains a crosslinking agent, and in this case, the performance of the easy-adhesion layer is improved. The crosslinking agent is not particularly limited. When the urethane resin has a carboxyl group, the crosslinking agent is preferably a polymer having a group capable of reacting with the carboxyl group. Examples of the group capable of reacting with a carboxyl group are an organic amino group, an oxazoline group, an epoxy group, and a carbodiimide group, and an oxazoline group is preferable. A cross-linking agent having an oxazoline group has a long pot life at room temperature when mixed with a urethane resin, and has a good workability because a cross-linking reaction proceeds by heating. The polymer is, for example, a (meth) acrylic polymer or a styrene / acrylic polymer, and a (meth) acrylic polymer is preferable.

  The resin dispersion used for the easy-adhesion layer preferably contains fine particles. In this case, the anti-blocking property of the finally formed retardation film is improved.

  The fine particles are not particularly limited, and are, for example, water-dispersible fine particles, which may be either inorganic fine particles or organic fine particles. Inorganic fine particles include, for example, inorganic oxides such as silica, titania, alumina, zirconia, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, and the like. It is. The organic fine particles are, for example, fine particles of silicone resin, fluorine resin, or acrylic resin.

  The fine particles are preferably silica fine particles. Silica fine particles are highly effective in improving anti-blocking properties. Moreover, since it is excellent in transparency, coloring of the retardation film finally obtained and increase in a haze rate do not easily occur. In addition to this, the silica fine particles have good dispersibility and dispersion stability in the dispersion of the urethane resin, and have high adhesion to the acrylic resin film.

  When the resin is an aqueous dispersion, the fine particles are preferably blended as an aqueous dispersion such as colloidal silica. Colloidal silica may be a commercially available product, for example, Quartron PL series manufactured by Fuso Chemical Industry, Snowtex series manufactured by Nissan Chemical Industries, Aerodisp series and Aerosil series manufactured by Nippon Aerosil, and Seahoster series manufactured by Nippon Shokubai.

  When the resin dispersion contains fine particles, the content of fine particles in the dispersion is preferably less than 1% by weight, more preferably less than 0.5% by weight, and even more preferably less than 0.3% by weight. When the content of the fine particles is excessively large, the strength of the formed easy-adhesion layer may be reduced.

  The resin dispersion may contain any material other than the above-described materials as long as the effects of the present invention are obtained. Examples of the material include a dispersion stabilizer, a thixotropic agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a thickener, a dispersant, a surfactant, a catalyst, and an antistatic agent.

  When the laminate of the present invention is used as a polarizer protective film, it is preferably adhered to the polarizer via an adhesive layer. The polarizer may be any polarizer as long as it has a function of transmitting only light having a specific vibration direction. For example, a polyvinyl alcohol film is stretched and dyed with iodine or a dichroic dye. Polyvinyl alcohol polarizers; polyene polarizers such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride; reflective polarizers using multilayer laminates or cholesteric liquid crystals; thin film crystal films Among these, a polarizer obtained by dyeing a polyvinyl alcohol-based fat film with a dichroic material and uniaxially stretching is preferably used. The thickness of these polarizers is not particularly limited, and is generally about 5 to 100 micrometers.

  Examples of preferable adhesives with the polarizer include, for example, polyvinyl alcohol resins, polyacrylic resins, polyurethane resins, polyester resins, and adhesives that are cured with active energy rays such as ultraviolet rays and electron beams. And adhesives such as acrylic, silicon and rubber. Needless to say, the thermocompression bonding may be performed under the condition that the polarizing function of the polarizer is not lowered. In that case, the bonding can be performed under a mild thermocompression bonding condition.

  Examples of adhesive additives include adhesion promoters typified by silane coupling agents and ethylene oxide, additives that improve wettability with transparent protective films, curing rates by electron beams typified by carbonyl compounds, etc. Sensitizers that increase sensitivity, such as acryloxy group compounds and hydrocarbons (natural and synthetic resins), additives that improve mechanical strength and processability, UV absorbers, anti-aging agents, dyes, processing aids Agents, ion trapping agents, antioxidants, tackifiers, fillers (other than metal compound fillers), plasticizers, leveling agents, foaming inhibitors, antistatics and the like.

  The method of adhering using the above-mentioned adhesive is not particularly limited. For example, kiss coat, spin coat, roll coat, dip coat, curtain coat, bar coat, doctor -Blade coating, knife coating, air knife coating, die coating, gravure coating, micro gravure coating, offset gravure coating, lip coating, spray coating, comma coating, etc. The method of apply | coating an adhesive agent to the adhesive surface of a polarizer, and superimposing both can be used. After the adhesive is applied, the polarizer and the film bonded thereto are sandwiched by nip rolls and bonded together. In the case of bonding, the optical axis of the laminate and the absorption axis of the polarizer are preferably arranged orthogonally or in parallel.

  When the E layer is an adhesive layer, the adhesive that forms the adhesive layer is not particularly limited. For example, an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based or rubber-based polymer, etc. Can be selected and used as appropriate.

  The attachment of the adhesive layer can be performed by an appropriate method. For example, a pressure sensitive adhesive solution of about 10 to 40% by weight in which a base polymer or a composition thereof is dissolved or dispersed in a solvent composed of a suitable solvent alone or a mixture such as toluene and ethyl acetate is prepared. A method in which it is directly attached on the surface of the retardation film (D layer) by an appropriate development method such as a casting method or a coating method, or an adhesive layer is formed on the separator and the retardation film (D layer is formed). ) Or a method of attaching an adhesive tape having a separator (protective layer) on one side to the surface of the retardation film (D layer).

  Any appropriate film can be adopted as the separator. Examples of the material for the surface protective film include polyethylene terephthalate and polycarbonate. Preferably, it is a polyethylene terephthalate that has been subjected to a release treatment. Particularly preferred is polyethylene terephthalate having a flexural modulus of 5000 MPa or more.

  The thickness of a separator becomes like this. Preferably it is 15-200 micrometers, More preferably, it is 30-150 micrometers, More preferably, it is 50-100 micrometers. If the thickness of the separator is less than 15 μm, the effects of the present invention may not be sufficiently exhibited. When the thickness of the separator is larger than 200 μm, it is not economical and roll transportability may be deteriorated.

  Various functional coating layers may be formed on the surface of the laminate of the present invention as necessary. The functional coating layer is, for example, an antistatic layer, an adhesive layer, an antiglare (non-glare) layer, an antifouling layer such as a photocatalyst layer, an antireflection layer, a hard coat layer, an ultraviolet ray shielding layer, a heat ray shielding layer, an electromagnetic wave shielding layer, For example, a gas barrier layer.

  The use of the laminate of the present invention is not particularly limited, but can be suitably used as an optical member due to its high transparency and heat resistance. In particular, in VA type and IPS type liquid crystal display devices (LCD), organic EL, plasma display, electronic paper, 3D display, field emission display (FED) and other image display devices, polarizer protective film, retardation film, visual field It is suitable as an optical film such as a corner compensation film, a light diffusion film, a reflection film, an antireflection film, an antiglare film, a brightness enhancement film, a conductive film for touch panel, and an optical protective film.

  The present invention is not limited to the configurations described above, and various modifications can be made within the scope described in the specification, and implementations obtained by appropriately combining technical means disclosed in different embodiments. The form is also included in the technical scope of the present invention. Moreover, all the literatures described in this specification are used as reference. EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited only to this Example.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following description, “%” represents “mass%” and “part” represents “part by mass” unless otherwise specified. For convenience, the following abbreviations are used in the examples.

MMA: methyl methacrylate MHMA: 2- (hydroxymethyl) methyl acrylate MA: methyl acrylate NVCz: N-vinylcarbazole AN: acrylonitrile BA: butyl acrylate [weight average molecular weight and number average molecular weight]
The weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin were determined according to the following measurement conditions using gel permeation chromatography (GPC).

Measurement system: Tosoh GPC system HLC-8220
Developing solvent: Chloroform (Wako Pure Chemical Industries, special grade)
Solvent flow rate: 0.6 mL / min Standard sample: TSK standard polystyrene (manufactured by Tosoh, PS-oligomer kit)
Measurement side column configuration: guard column (manufactured by Tosoh, TSK guardcolumn Super HZ-L), separation column (manufactured by Tosoh, TSK Gel Super HZM-M), two in series -RC)
[Glass-transition temperature]
The glass transition temperature (Tg) of the resin and film was determined in accordance with the provisions of JIS K7121. Specifically, using a differential scanning calorimeter (Rigaku, Thermo plus EVO DSC-8230), a sample of about 10 mg was heated from room temperature to 200 ° C. (heating rate 20 ° C./min) in a nitrogen gas atmosphere. From the DSC curve obtained in this way, the starting point method was used for evaluation. Α-alumina was used as a reference.
[Refractive index anisotropy]
The in-plane retardation Re (447) and Re (590) of the optical film with respect to light having wavelengths of 447 and 590 nm were determined using a phase difference measuring device (manufactured by Oji Scientific Instruments, KOBRA-WR). Specifically, the incident angle dependency (single N calculation) is selected as the measurement item, the average refractive index of the film measured with an Abbe refractometer, with the tilt axis as the slow axis and the incident angle as 40 °, The film thickness d was input and measured. The film thickness d of the optical film was measured using a Digimatic micrometer (manufactured by Mitutoyo).

  In the in-plane retardation Re of the optical film, nx is the refractive index in the slow axis direction (direction showing the maximum refractive index in the film plane) in the plane of the film, and ny is the fast axis direction in the plane of the film ( The refractive index in a direction perpendicular to nx in the film plane, d is a value represented by the formula Re = (nx−ny) × d, where the thickness of the film is (nm).

Re (447) / Re (590) represents the ratio of the in-plane phase difference obtained by measuring the incident light at 447 nm and 590 nm, and is represented by D.
[Surface roughness]
The maximum height Rz, which is a parameter for the surface roughness, was determined in accordance with the provisions of JIS B 0601-2001. As a measuring apparatus, a laser microscope VK-9700 (manufactured by Keyence) was used.
[Haze]
Haze and internal haze were measured using NDH-1001DP manufactured by Nippon Denshoku Industries Co., Ltd.
(Production Example 1)
MHMA 15 parts, MMA 27 parts, MA 10 parts, NVCz 6 parts, toluene 37 parts and methanol 2 parts were charged into a reaction vessel equipped with a stirrer, temperature sensor, cooling pipe, nitrogen introduction pipe and dropping funnel. While introducing nitrogen gas into the reaction vessel, the temperature was raised to 95 ° C. and refluxing was started. As a polymerization initiator, t-amylperoxy-2-ethylhexanoate (manufactured by Arkema Yoshitomi Co., Ltd .; “Lupelox (registered trademark)” ) 575 ") 0.029 part was added and simultaneously dropwise addition of a mixture of 15 parts MHMA, 27 parts MMA, 17 parts toluene and 0.082 parts t-amylperoxy-2-ethylhexanoate. While this mixture was added dropwise over 8 hours, solution polymerization was performed at about 90 ° C. to 100 ° C. under reflux.

  Further, 23.3 parts of toluene was dropped over 3 hours from 5 hours from the start of polymerization to dilute the polymerization solution.

  To the obtained copolymer solution, 0.24 part of an octyl phosphate / dioctyl mixture (manufactured by Sakai Chemical Industry Co., Ltd .; trade name “Phoslex A-8”) was added and refluxed at 80 ° C. to 105 ° C. for 2 hours. A cyclization condensation reaction was performed.

  Thereafter, 21.4 parts of methyl isobutyl ketone (MIBK) was added to dilute the resulting copolymer solution.

Next, the obtained copolymer solution was heated to 240 ° C. through a heat exchanger, barrel temperature 240 ° C., degree of vacuum 13.3 to 400 hPa (10 to 300 mmHg), rear vent number 1 and fore vent number 4 Vent type screw twin screw extruder (L / D) in which a single piece (referred to as the first, second, third and fourth vents from the upstream side) and a leaf disk type polymer filter (filtration accuracy 5 μm) are arranged at the tip = 52) was introduced at a processing rate of 8 parts / hour in terms of resin amount, and devolatilization was performed. At that time, a separately prepared mixed solution of antioxidant / cyclization catalyst deactivator was added at a rate of 0.305 parts / hour from the back of the second vent, and 0.04 part / hour of ion-exchanged water. Each was added from behind the third vent at a charging speed of. The mixture of antioxidant / cyclization catalyst deactivator was 0.0214 parts Irganox 1010 from Ciba Specialty Chemicals, 0.0214 parts ADEKA Adekastab AO-412S and 0.322 parts zinc octylate (Nippon Chemical Industry). Manufactured by Nikka Octics Zinc, 18%) and dissolved in 2.51 parts of toluene. (Note that Irganox 1010 and AO-412S are each contained in 0.025% in the resin.)
After the devolatilization step, the resin (intramolecular cyclized methacrylic copolymer) was pelletized to obtain a pellet of the resin (A-1). The weight average molecular weight of the obtained resin (A-1) was 102,000, and Tg was 132 ° C.
(Production Example 2)
In a pressure-resistant reaction vessel equipped with a stirrer, 70 parts of deionized water, 0.5 part of sodium pyrophosphate, 0.2 part of potassium oleate, 0.005 part of ferrous sulfate, 0.2 part of dextrose, p-menthane hydro A reaction mixture comprising 0.1 part of peroxide and 28 parts of 1,3-butadiene was added, the temperature was raised to 65 ° C., and polymerization was carried out for 2 hours. Next, 0.2 parts of p-hydroperoxide was added to the reaction mixture, and 72 parts of 1,3-butadiene, 1.33 parts of potassium oleate, and 75 parts of deionized water were continuously added dropwise over 2 hours. The reaction was continued for 21 hours from the start of polymerization to obtain a butadiene-based rubber polymer latex having an average particle size of 0.240 μm.
In a polymerization vessel equipped with a cooler and a stirrer, 120 parts of deionized water, 50 parts of the butadiene rubber polymer latex as a solid content, 1.5 parts of potassium oleate, sodium formaldehyde sulfoxylate (SFS) 0 .6 parts was charged, and the inside of the polymerization vessel was sufficiently replaced with nitrogen gas.

  Subsequently, after raising the internal temperature to 70 ° C., a mixed monomer solution consisting of 36.5 parts of styrene and 13.5 parts of acrylonitrile, 0.27 parts of cumene hydroxyperoxide, and 20 parts of deionized water are polymerized. Polymerization was carried out while continuously dropping the initiator solution separately over 2 hours. After completion of the dropwise addition, the internal temperature was raised to 80 ° C. and polymerization was continued for 2 hours. Next, after cooling to an internal temperature of 40 ° C., it was passed through a 300 mesh wire net to obtain an emulsion polymerization liquid of elastic organic fine particles.

The obtained emulsion polymerization liquid of elastic organic fine particles is salted out with calcium chloride, coagulated, washed with water and dried to obtain powdered elastic organic fine particles (G, average particle size: 0.260 μm, refraction of soft polymer layer). Ratio: 1.516).
(Production Example 3)
A reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, a nitrogen introduction tube, and a dropping funnel was charged with 25 parts of NVCz, 10 parts of AN, 15 parts of BA, and 29.6 parts of methyl ethyl ketone as a polymerization solvent. While introducing nitrogen gas into the reaction vessel, the temperature was raised to 85 ° C., and when refluxing was started, t-amylperoxy-2-ethylhexanoate (manufactured by Arkema Yoshitomi, trade name: Luperox 575) was used as a polymerization initiator. At the same time, dropwise addition of a mixture of 20 parts of methyl ethyl ketone and 0.01 part of t-amylperoxy-2-ethylhexanoate was started. While this mixture was added dropwise over 6 hours, solution polymerization was performed at about 80 ° C. to 85 ° C. under reflux.

Next, the polymer solution obtained by the reaction was subjected to a barrel temperature of 240 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa, a rear vent number of 1, a fore vent number of 4 (first, second, It was introduced into a vent type screw twin screw extruder (L / D = 52.5) (referred to as third and fourth vents) at a treatment rate of 2 kg / hour in terms of resin amount, and devolatilization was performed. Through this devolatilization step, the product was cut and pelletized using a strand cutter to obtain polymer pellets (A-2). The obtained pellet (A-2) had a weight average molecular weight of 291,000 and a Tg of 102 ° C.
(Production Example 4)
MMA 10.9 parts, MHMA 19.1 parts, EMA 24.6 parts, toluene 43 parts as polymerization solvent, methanol 1.5 parts and antioxidant in a reaction kettle equipped with a stirrer, thermometer, condenser and nitrogen introduction tube As a polymerization initiator, 0.027 part of Adeka Stub 2112 (manufactured by ADEKA) was charged and heated to 88 ° C. through nitrogen. Eight (manufactured by Arkema Yoshitomi, trade name: Luperox 575) and a solution of 0.044 parts of t-amylperoxy-2-ethylhexanoate dissolved in 0.8 parts of toluene over 8 hours After 3 hours, 21.1 parts of toluene was added dropwise over 4 hours, and the solution polymerization was allowed to proceed under reflux at about 95 to 100 ° C. After, it was further aged for 1 hour.

  Next, 0.16 part of stearyl phosphate (trade name: Phoslex A-18, manufactured by Sakai Chemical Industry Co., Ltd.) is added to the polymer solution, and the cyclization condensation reaction proceeds for 2 hours under reflux at about 80 to 95 ° C. I let you.

Next, the polymer solution obtained by the cyclization condensation reaction was completed through a multi-tube heat exchanger heated to 240 ° C., and then the barrel temperature was 240 ° C., the rotation speed was 100 rpm, and the degree of vacuum was 13 .3-400 hPa, rear vent number 1 and fore vent number 4 (referred to as first, second, third and fourth vents from the upstream side) vent type screw twin screw extruder (L / D = 52.5 Was introduced at a treatment rate of 24 parts / hour in terms of the amount of resin and devolatilized. At that time, ion exchange water was injected at a rate of 0.4 part / hour after the first vent and the third vent. Further, separately prepared antioxidant and quencher mixed solution after the second vent was injected at a charging rate of 1.1 parts / hour. Antioxidants and deactivators were 0.6 parts Irganox 1010 manufactured by Ciba Specialty Chemicals, 0.6 parts Adeka Stub AO-412S manufactured by ADEKA, and zinc octylate (manufactured by Nippon Chemical Industry Co., Ltd., 3.6% Nikka octix zinc) 4 Prepared by dissolving 2 parts in 94.7 parts of toluene. Through this devolatilization process, the resin was cut and pelletized using a strand cutter to obtain an acrylic resin pellet (A-3) having a ring structure in the main chain. The obtained pellet (A-3) had a weight average molecular weight of 10,000,000 and a Tg of 126 ° C.
(Comparative Example 1)
The resin (A-1) produced in Production Example 1 and the elastic organic fine particles (G) produced in Production Example 2 have a mass ratio of (A-1) / (G) = 88.9 / 11.1. Were kneaded at 240 ° C. using a twin screw extruder to obtain pellets (B-1). This pellet (B-1) was melt-extruded under the following conditions using a single screw extruder to produce an unstretched film (C-1) having a thickness of 210 μm. The obtained unstretched film had a Tg of 128 ° C. and an internal haze per 100 μm of 0.3%. In addition, the obtained unstretched film is roll shape, and makes the width direction of the roll in the said film TD direction, and makes the extending | stretching direction (direction orthogonal to TD direction in a film surface) MD direction.

Cylinder temperature: 240 ° C
Die: Coat hanger type, width 150mm, temperature 260 ° C
Casting: Keep two rolls with gloss, first roll and second roll at 130 ° C. Next, the produced unstretched film (C-1) is cut into 97 mm × 97 mm, and a corner stretch type biaxial stretch test apparatus ( Using Toyo Seiki's X6-S), the film was stretched in the MD direction at a temperature of Tg or higher. Specifically, the distance between chucks when set in the test apparatus is 80 mm in the X direction and 80 mm in the Y direction, and after preheating at 137 ° C. for 3 minutes, the draw ratio is 2.25 times in the MD direction. The fixed end uniaxial stretching was performed to obtain a retardation film (D-1) having a thickness of 100 μm. The in-plane retardation Re (447) of the obtained stretched film (D-1) is 122 nm, Re (590) is 128 nm, D is 0.96, haze is 6.3%, and Rz is 2.32 μm. there were. The internal haze per 100 μm was 0.3%.
Example 1
An aqueous primer comprising ion exchange water / urethane resin (Daiichi Kogyo Seiyaku, Superflex 210, solid content 35% by weight) = 4/1 on both surfaces of the retardation film (D-1) obtained in Comparative Example 1. Bar coater No. 4 and then dried at 100 ° C. for 2 minutes to form another layer (E-1). The haze of the obtained laminate (F-1) was 1.0%, and Rz was 0.55 μm.
(Example 2)
On both surfaces of the retardation film (D-1) obtained in Comparative Example 1, ion-exchanged water / isopropyl alcohol / urethane resin (Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) = 1/7 / A solvent-based primer consisting of 2 bar coater no. 4 and then dried at 100 ° C. for 2 minutes to form another layer (E-2). The haze of the obtained laminate (F-2) was 1.2%, and Rz was 0.56 μm.
(Example 3)
After pasting the transparent double-sided adhesive tape (MCS65) on both sides of the retardation film (D-1) obtained in Comparative Example 1, the protective layer PET was peeled off, and another layer (E-3) was attached. Formed. The haze of the obtained laminate (F-3) was 1.0%, and Rz was 0.53 μm.
(Comparative Example 2)
The non-stretched film (C-1) produced in Comparative Example 1 was uniaxially stretched at 141 ° C. with a biaxial stretching device so that the stretching ratio was 2.5 times, and a retardation film having a thickness of 90 μm. (D-2) was obtained. The in-plane retardation Re (447) of the retardation film (D-2) was 132 nm, Re (590) was 138 nm, D was 0.96, haze was 2.8%, and Rz was 1.44 μm. . The internal haze per 100 μm was 0.3%.
Example 4
An aqueous primer comprising ion exchange water / urethane resin (Daiichi Kogyo Seiyaku, Superflex 210, solid content 35% by weight) = 4/1 on both surfaces of the retardation film (D-2) obtained in Comparative Example 2. Bar coater No. 4 and then dried at 100 ° C. for 2 minutes to form another layer (E-4). The haze of the obtained laminate (F-4) was 0.8%, and Rz was 0.48 μm.
(Example 5)
After pasting the transparent double-sided adhesive tape (MCS65) on both sides of the retardation film (D-2) obtained in Comparative Example 2, the protective layer PET was peeled off and another layer (E-5) was attached. Formed. The layered product (F-5) obtained had a haze of 1.1% and an Rz of 0.51 μm.
(Comparative Example 3)
Resin (A) produced in Production Example 1, elastic organic fine particles (G) produced in Production Example 2, and styrene-acrylonitrile copolymer (AS resin: ratio of styrene unit / acrylonitrile unit is 73 mass% / 27 mass% And a mass average molecular weight of 220,000) were kneaded at 240 ° C. using a twin screw extruder so as to obtain a mass ratio of 81/14/5 to obtain pellets (B-2). Furthermore, the obtained pellet (B-2) was melt-extruded under the same conditions as in Comparative Example 1 using a single-screw extruder to produce an unstretched film (C-2) having a thickness of 205 μm. The obtained unstretched film had a Tg of 129 ° C. and an internal haze per 100 μm of 0.2%. In addition, the obtained unstretched film is roll shape, and makes the width direction of the roll in the said film TD direction, and makes the extending | stretching direction (direction orthogonal to TD direction in a film surface) MD direction.

Next, the obtained unstretched film (C-2) was cut out to 97 mm × 97 mm and stretched at a temperature of Tg or more in the MD direction using a corner stretch type biaxial stretching test apparatus (X6-S, manufactured by Toyo Seiki Co., Ltd.). did. Specifically, the distance between chucks when set in the test apparatus is 80 mm in the X direction and 80 mm in the Y direction, and after preheating at 132 ° C. for 3 minutes, the draw ratio is 2.8 times in the MD direction. The film was uniaxially stretched at the fixed end to obtain a retardation film (D-3) having a thickness of 73 μm. The in-plane retardation Re (447) of the retardation film (D-3) was 131 nm, Re (590) was 142 nm, D was 0.92, haze was 3.8%, and Rz was 1.77 μm. The internal haze per 100 μm was 0.3%.
(Example 6)
An aqueous primer comprising ion exchange water / urethane resin (Daiichi Kogyo Seiyaku, Superflex 210, solid content 35% by weight) = 4/1 on both surfaces of the retardation film (D-3) obtained in Comparative Example 3. Bar coater No. 4 and then dried at 100 ° C. for 2 minutes to form another layer (E-6). The laminate (F-6) obtained had a haze of 1.0% and Rz of 0.50 μm.
(Example 7)
After pasting the transparent double-sided adhesive tape (MCS65) on both sides of the retardation film (D-3) obtained in Comparative Example 2, the protective layer PET is peeled off and another layer (E-7) is attached. Formed. The layered product (F-7) obtained had a haze of 1.1% and an Rz of 0.52 μm.
(Comparative Example 4)
12.8 parts of pellet (A-2) prepared in Production Example 3, 73.7 parts of pellet (A-3) prepared in Production Example 4, and elastic organic fine particles (G) produced in Production Example 2 13. 5 parts were dry blended, melt kneaded at a barrel temperature of 240 ° C. using a twin screw extruder, and cut using a strand cutter to obtain pellets (B-3).

  Furthermore, the obtained pellet (B-3) was melt-extruded under the following conditions using a single screw extruder to produce an unstretched film (C-3) having a thickness of 250 μm. The obtained unstretched film had a Tg of 124 ° C.

Cylinder temperature: 250 ° C
Die: Coat hanger type, width 150mm, temperature 260 ° C
Casting: 2 rolls with gloss, 1st roll and 2nd roll are kept at 120 ° C. Subsequently, the obtained unstretched film (C-3) is cut into 97 mm × 97 mm, and a corner stretch type biaxial stretching test apparatus (Toyo Using an X6-S) manufactured by Seiki, the film was stretched in the MD direction at a temperature of Tg or higher. Specifically, the distance between chucks when set in the test apparatus was 80 mm in the X direction and 80 mm in the Y direction, and after preheating the film at 132 ° C. for 3 minutes, the draw ratio was 2.8 times in the MD direction. A fixed end uniaxial stretching was performed to obtain a retardation film (D-4) having a thickness of 86 μm. In the retardation film (D-4), the in-plane retardation Re (447) was 124 nm, Re (590) was 139 nm, D was 0.89, haze was 2.7%, and Rz was 1.26 μm. . The internal haze per 100 μm was 0.3%.
(Example 8)
An aqueous primer comprising ion exchange water / urethane resin (Daiichi Kogyo Seiyaku, Superflex 210, solid content 35% by weight) = 4/1 on both surfaces of the retardation film (D-4) obtained in Comparative Example 3. Bar coater No. 4 and then dried at 100 ° C. for 2 minutes to form another layer (E-8). The laminate (F-8) obtained had a haze of 1.0% and Rz of 0.50 μm.
Example 9
After pasting the transparent double-sided adhesive tape (MCS65) on both sides of the retardation film (D-4) obtained in Comparative Example 3, the protective layer PET was peeled off and another layer (E-9) was attached. Formed. The layered product (F-9) obtained had a haze of 1.2% and an Rz of 0.56 μm.
(Example 10)
An aqueous primer comprising ion exchange water / urethane resin (Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) = 4/1 on one side of the retardation film (D-1) obtained in Comparative Example 1. Bar coater No. 4 and then dried at 100 ° C. for 2 minutes to form another layer (E-10a). Furthermore, after attaching a transparent double-sided adhesive tape (MCS65) to the other surface of the retardation film (D-1), the protective layer PET was peeled off to form another layer (E-10b). The haze of the obtained laminate (F-10) was 1.1%, the Rz on the E-10a side was 0.55 μm, and the Rz on the E-10b side was 0.61 μm.
(Comparative Example 5)
The unstretched film (C-2) produced in Comparative Example 3 was uniaxially stretched at 140 ° C. with a biaxial stretching device so that the stretching ratio was 2.8 times, and a retardation film having a thickness of 75 μm. (D-5) was obtained. The in-plane retardation Re (447) of the retardation film (D-5) was 83 nm, Re (590) was 90 nm, D was 0.92, haze was 1.8%, and Rz was 0.84 μm. . The internal haze per 100 μm was 0.2%.
(Comparative Example 6)
The unstretched film (C-1) produced in Comparative Example 1 is uniaxially stretched at 141 ° C. so that the stretching ratio is 2.25 times by a biaxial stretching device, and is a retardation film having a thickness of 100 μm. (D-6) was obtained. The in-plane retardation Re (447) of the retardation film (D-6) was 119 nm, Re (590) was 124 nm, D was 0.96, haze was 2.4%, and Rz was 1.12 μm. . The internal haze per 100 μm was 0.2%.
(Comparative Example 7)
The unstretched film (C-1) produced in Comparative Example 1 was uniaxially stretched at 143 ° C. so that the stretch ratio was 2.5 times by a biaxial stretching apparatus, and a retardation film having a thickness of 90 μm. (D-7) was obtained. The in-plane retardation Re (447) of the retardation film (D-7) was 100 nm, Re (590) was 104 nm, D was 0.96, haze was 2.1%, and Rz was 0.96 μm. . The internal haze per 100 μm was 0.2%.

  Table 1 shows the film thickness (μm) at which the haze, Rz, and Re (590) of the retardation film (D layer) of Example 1-10 and Comparative Example 1-7 are 140 nm.

  INDUSTRIAL APPLICABILITY The present invention can be widely used in various technical fields using an optical film such as an image display device such as a liquid crystal display device.

Claims (9)

A laminate having another layer (E layer) on at least one side of the retardation film (D layer),
The retardation film (D layer) includes elastic organic fine particles (G) and an acrylic resin (A), and another layer (E layer) is laminated on the retardation film (D layer) having a maximum height of Rz (D). The laminated body obtained by doing and the maximum height Rz (E) of the surface on the opposite side to D layer of E layer satisfy | fills a following formula.
Rz (D)> Rz (E)   The laminate according to claim 1, wherein the laminate has a haze of 2% or less.   The laminate according to claim 1 or 2, wherein the E layer is an easy adhesion layer.   The laminate according to claim 1 or 2, wherein the E layer is an adhesive layer.   3. The laminate according to claim 1, further comprising another layer (E layer) on both surfaces of the retardation film (D layer), wherein one of the E layers is an easy adhesion layer and the other is an adhesive layer. .   The laminate according to any one of claims 1 to 5, wherein the elastic organic fine particles (G) contain a conjugated diene monomer structural unit constructed by polymerizing a conjugated diene monomer as an essential component.   The laminate according to any one of claims 1 to 6, wherein the acrylic resin (A) has a ring structure in the main chain.   In the retardation film (D layer), the ratio Re (447) / Re (590) of in-plane retardation Re (447) and Re (590) with respect to light having a wavelength of 447 and 590 nm is 0.75 or more and 0.97. It is the following, The laminated body in any one of Claims 1-7. The laminate according to any one of claims 1 to 8, wherein the retardation film (D layer) has a thickness of 110 µm or less so that Re (590) is 140 nm.