JP2015136792A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate, which has high hardness surfaces with excellent scratch resistance and flexibility, and is good in visibility after a wet heat treatment, foreign matter detectability, hard coat adhesiveness, impact resistance, curling property, and moldability.SOLUTION: The laminate comprises: on both surfaces of an adhesive layer, polyester films having coating layers on both surfaces and having plane orientation (ΔP) of 0.05 to 0.15 and a thickness of 125 to 350 μm; and, on both exposed surfaces of the coating layers, hard coat layers of a thickness of 2 to 100 μm. Total light transmittance of the laminate is 90% or more, and a rate of change in film haze (ΔH) of the laminate before and after a wet heat treatment under an atmosphere of 85°C and 85% RH for 100 hours is 1.5% or less.

Description

  The present invention is a hard surface having high hardness and excellent scratch resistance and flexibility, particularly for the purpose of replacing curved glass in various fields such as in-vehicle, building materials, and optics (for example, display surface protection). And a laminate having good visibility after wet heat treatment, foreign matter detection, hard coat adhesion, impact resistance, curling property, and moldability.

  Conventionally, an image display surface in an image display device such as a liquid crystal display or an organic EL display is required to be provided with scratch resistance so as not to be damaged during use. Therefore, the scratch resistance of the image display surface of the image display device may be improved by using a hard coat film in which a hard coat layer is laminated on the surface of the base film.

  There are various methods for laminating a hard coat layer on a base film, such as a method of forming a harder resin layer on a base film using a photopolymerizable resin such as a thermosetting resin or an ultraviolet curable resin. A method has been proposed. Moreover, depending on the kind of hard coat layer, the flexibility as a laminate is insufficient when the polyester films are bonded together, and the hard coat layer may be cracked when the film laminate is folded ( For example, Patent Document 1).

  As an alternative to glass used for electronic parts, when the use of a polyester film laminate is assumed, the required characteristics are stable in an atmosphere of constant temperature and humidity (eg, 85 ° C., 85% RH, etc.). It is common to perform a reliability test to confirm that the

  In this case, in the laminate structure in which the polyester film is bonded through the pressure-sensitive adhesive layer, the low molecular weight substance and oligomer (mainly ester cyclic trimer) in the polyester film precipitate and crystallize after the wet heat treatment. The visibility may decrease with the increase in film haze.

  For this reason, when an oligomer precipitation prevention measure is taken, for example, when the oligomer precipitation prevention layer described in Patent Document 2 is laminated on the polyester film surface, oligomer precipitation is suppressed, but adhesion to the functional layer, for example, The adhesiveness to the hard coat layer is poor.

  On the other hand, when an easy-adhesion layer for a hard coat layer (for example, Patent Document 3) that is generally used is laminated on a polyester film, adhesion to the hard coat layer is good, but oligomer precipitation is prevented. The effect is insufficient. Therefore, when used as a constituent member of a polyester film laminate, it is necessary to have a coating layer that achieves a high level of conflicting properties such as prevention of oligomer precipitation of the polyester film after wet heat treatment and adhesion to the hard coat layer. Has been.

  In recent years, for display applications and the like, product design with features in design characteristics has been performed with diversification of products. For example, when using curved glass as a display component, considering a replacement with a polyester film laminate, if the laminate has insufficient moldability, it is difficult to form with a desired curvature. May be. On the other hand, even if molding of the laminate is possible, the laminate may be restored to its original shape before molding over time (for example, after 24 hours).

  Therefore, in a laminate having a polyester film as a constituent member, it is necessary to make compatible properties such as moderate rigidity and good moldability possessed by the polyester film themselves at a high level.

JP2013-35210A Patent No. 5236586 JP 2010-89307 A

  The present invention has been made in view of the above circumstances, and the problem to be solved is, for example, having a hard surface with high hardness excellent in scratch resistance and flexibility, and visibility after wet heat treatment, foreign matter detection. It is to provide a laminate having good properties, hard coat adhesion, impact resistance, curling properties and moldability.

  As a result of intensive studies in view of the above circumstances, the present inventors have found that the above problems can be easily solved by a laminate having a specific configuration, and have completed the present invention.

  That is, the gist of the present invention is that the surface orientation (ΔP) is 0.05 to 0.15, the thickness is 125 to 350 μm, the polyester film having a coating layer on both sides, on both sides of the pressure-sensitive adhesive layer, It is a laminate having a hard coat layer having a thickness (after drying) of 2 to 100 μm on both surfaces of the exposed coating layer, the total light transmittance of the laminate is 90% or more, and at 85 ° C. and 85% RH atmosphere, It exists in the laminated body characterized by the film haze change rate ((DELTA) H) of a laminated body before and after 100-hour wet heat treatment being 1.5% or less.

  The present invention relates to a laminate, for example, as an alternative to curved glass, has a hard surface with high hardness and excellent scratch resistance, flexibility, visibility after wet heat treatment, UV absorption performance, hard coat adhesion, It is suitable as a laminate having good impact resistance and moldability, and its industrial value is high.

Schematic sectional view showing an example of the laminate of the present invention Schematic diagram showing the shape of the mold used for the moldability evaluation of the laminate of the present invention Typical sectional drawing which shows the shape of the metal mold | die used for the moldability evaluation of the laminated body of this invention

  In the present invention, the polyester film constituting the laminate may be a single layer structure or a laminated structure. For example, a layer other than a two-layer or three-layer structure may be a four-layer or a layer as long as the gist of the present invention is not exceeded. It may be a multilayer having more than that, and is not particularly limited.

  The polyester used in the present invention is a resin comprising a general dicarboxylic acid structural unit and a diol structural unit. Suitable monomers for the dicarboxylic acid structural unit include terephthalic acid, isophthalic acid, phthalic acid, and 2-methylterephthalic acid. Acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, aromatic dicarboxylic acid such as tetralindicarboxylic acid, and These ester-forming derivatives, succinic acid, glutaric acid, adipic acid, pimelic acid, corkic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, norbornanedicarboxylic acid, tricyclodecanedicarboxylic acid, Pentacyclod Saturated alicyclic dicarboxylic acids such as dicarboxylic acids, and, like ester-forming derivatives thereof are exemplified.

  Suitable monomers for the diol structural unit include aliphatics such as ethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, propylene glycol, and neopentyl glycol. Polyether compounds such as diols, polyethylene glycol, polypropylene glycol, polybutylene glycol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2-decahydronaphthalenediethanol, 1,3 -Decahydronaphthalene diethanol, 1,4-decahydronaphthalene diethanol, 1,5-decahydronaphthalene diethanol, 1,6-decahydronaphthalene diethanol, 2,7-decahydronaphthalene Alicyclic diols such as dimethanol, tetralin dimethanol, norbornene dimethanol, tricyclodecane dimethanol, pentacyclododecane dimethanol, 4,4 ′-(1-methylethylidene) bisphenol, methylene bisphenol (bisphenol F) ), 4,4′-cyclohexylidene bisphenol (bisphenol Z), 4,4′-sulfonyl bisphenol (bisphenol S), and alkylene oxide adducts of the bisphenols. In addition, aromatic dihydroxy compounds such as hydroquinone, resorcin, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylbenzophenone, and alkylene oxide adducts of the aromatic dihydroxy compounds And diols having a cyclic acetal skeleton.

  In the above polyester, aromatic dicarboxylic acids as dicarboxylic acid structural units and ester-forming derivatives thereof are preferable from the viewpoint of versatility, and terephthalic acid, isophthalic acid, naphthalenedicarboxylic acids, or ester-forming derivatives thereof are Is preferred. The blending ratio of terephthalic acid and / or isophthalic acid and / or naphthalenedicarboxylic acid to the total dicarboxylic acid component is 70 mol% or more, preferably 85 mol from the viewpoint of compatibility when mixed with other polyester resins. % Or more, particularly preferably 95 mol% or more.

  In the above polyester, the diol structural unit is preferably an aliphatic diol such as ethylene glycol, trimethylene glycol, 1,4-butanediol, propylene glycol, neopentyl glycol, etc. from the viewpoint of versatility, and branched. Application of neopentyl glycol, which is an aliphatic glycol, and 1,4-cyclohexanedimethanol, which is an alicyclic glycol, is preferable from the viewpoint of transparency and moldability, and 10 to 60 mol% is preferable in all diol components, and 15 to 50 mol. % Is particularly preferred. Furthermore, in addition to these diol structural units, it is desirable to apply 1,3-propanediol or 1,4-butanediol from the viewpoint of moldability, and the total diol component is preferably 70 mol% or more, particularly preferably. 90 mol% or more is preferable.

  The polyester is a monoalcohol such as butyl alcohol, hexyl alcohol and octyl alcohol, a trihydric or higher polyhydric alcohol such as trimethylolpropane, glycerin and pentaerythritol, benzoic acid, Monocarboxylic acids such as propionic acid and butyric acid can be used as raw material monomers.

  In a preferred embodiment, the polyester film of the present invention is a copolyester resin. The copolyester can be obtained by blending a copolyester obtained by copolymerizing the above-described polyester with a third component as a co-polymerization component, or two or more homopolyesters. From the viewpoint of controlling the elastic modulus of the copolymerized polyester resin film, for example, when terephthalic acid and ethylene glycol are the main components, the other third component is preferably 3 to 50 mol%, more preferably 4 to 30 mol%. More preferably, it is preferable to contain 5 to 20 mol%.

  The third component is not particularly limited. Examples of the dicarboxylic acid component include succinic acid, glutaric acid, adipic acid, pimelic acid, corkic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, and dodecane. Aliphatic dicarboxylic acids such as dicarboxylic acids, cyclohexanedicarboxylic acid, norbornane dicarboxylic acid, saturated cycloaliphatic dicarboxylic acids such as tricyclodecane dicarboxylic acid, pentacyclododecanedicarboxylic acid, and ester-forming derivatives thereof, etc. One or more selected from these can be appropriately selected and used.

  Similarly, suitable diol components used as the third component include aliphatic diols such as trimethylene glycol, 1,3-propanediol, 1,4-butanediol, propylene glycol and neopentyl glycol, 1,4-cyclohexane. Examples thereof include alicyclic diols such as dimethanol, and one or more selected from the group consisting of these can be appropriately selected and used. Further, neopentyl glycol, which is a branched aliphatic glycol, and 1,4-cyclohexanedimethanol, which is an alicyclic glycol, can also be used. Furthermore, it is desirable from the viewpoint of moldability to apply 1,3-propanediol or 1,4-butanediol in addition to these diol structural units.

  The polyester used for the polyester film in the present invention may be a homopolyester or a copolyester. In the case of a homopolyester, those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Representative polyester includes polyethylene terephthalate (PET) and the like. On the other hand, examples of the dicarboxylic acid component of the copolyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (eg, P-oxybenzoic acid). 1 type or 2 types or more are mentioned, As a glycol component, 1 type or 2 types or more, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1, 4- cyclohexane dimethanol, neopentyl glycol, is mentioned. In any case, the polyester referred to in the present invention refers to a polyester which is polyethylene terephthalate or the like in which 60 mol% or more, preferably 80 mol% or more is an ethylene terephthalate unit.

  In the present invention, it is preferable to blend particles in the polyester layer mainly for the purpose of imparting slipperiness. The kind of the particle to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness. Specific examples thereof include silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, and magnesium phosphate. , Particles of kaolin, aluminum oxide, titanium oxide and the like. Further, the heat-resistant organic particles described in JP-B-59-5216, JP-A-59-217755 and the like may be used. Examples of other heat-resistant organic particles include thermosetting urea resins, thermosetting phenol resins, thermosetting epoxy resins, benzoguanamine resins, and the like. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used.

  On the other hand, the shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular also about the hardness, specific gravity, a color, etc. These series of particles may be used in combination of two or more as required.

  The average particle size of the particles contained in the polyester film is preferably in the range of 0.2 to 3.0 μm. When the average particle size is less than 0.2 μm, the film surface may be flattened and the winding characteristics in the film production process may be inferior. On the other hand, when the average particle size exceeds 3.0 μm, it may be difficult to adapt to applications in which visibility is important due to generation of bright spots due to particles contained in the film.

  Furthermore, the particle content in the polyester layer is usually in the range of 0.001 to 5% by weight, preferably 0.005 to 3% by weight. When the particle content is less than 0.001% by weight, the slipperiness of the film may be insufficient. On the other hand, when the content exceeds 5% by weight, the transparency of the film is insufficient. There is.

  The method for adding particles to the polyester layer is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage of producing the polyester constituting each layer, but preferably a polycondensation reaction may be carried out after the esterification stage or after the transesterification reaction.

  Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyester raw material, or a blending of dried particles and a polyester raw material using a kneading extruder. It is done by methods.

  In order to correspond to the use which requires a weather resistance, it is preferable to contain a ultraviolet absorber in the polyester film of the base material constituting the double-side coated film of the present invention. The ultraviolet absorber is not particularly limited as long as it is a compound having ultraviolet absorbing ability and can withstand the heat applied in the production process of the polyester film.

  As the ultraviolet absorber, there are an organic ultraviolet absorber and an inorganic ultraviolet absorber. From the viewpoint of transparency, an organic ultraviolet absorber is preferable. Although it does not specifically limit as an organic type ultraviolet absorber, For example, a cyclic imino ester type, a benzotriazole type, a benzophenone type etc. are mentioned. From the viewpoint of durability, a cyclic imino ester type and a benzotriazole type are more preferable. It is also possible to use two or more ultraviolet absorbers in combination.

  Examples of the benzotriazole-based ultraviolet absorbers include, but are not limited to, 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2 '-Hydroxy-5'-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxypropyl) phenyl] -2H-benzotriazole, 2- [2'- Hydroxy-5 '-(methacryloyloxyhexyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5'-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2 -[2'-hydroxy-5'-tert-butyl-3 '-(methacryl Yloxyethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -5-chloro-2H-benzotriazole, 2- [2′-hydroxy-5 ′ -(Methacryloyloxyethyl) phenyl] -5-methoxy-2H-benzotriazole, 2- [2'-droxy-5 '-(methacryloyloxyethyl) phenyl] -5-cyano-2H-benzotriazole, 2- [2 '-Hydroxy-5'-(methacryloyloxyethyl) phenyl] -5-tert-butyl-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-nitro-2H -Benzotriazole and the like.

  Examples of the cyclic imino ester-based ultraviolet absorber include, but are not limited to, 2-methyl-3,1-benzoxazin-4-one, 2-butyl-3,1-benzoxazine-4, for example. -One, 2-phenyl-3,1-benzoxazin-4-one, 2- (1- or 2-naphthyl) -3, 1-benzoxazin-4-one, 2- (4-biphenyl) -3, 1-benzoxazin-4-one, 2-p-nitrophenyl-3,1-benzoxazin-4-one, 2-m-nitrophenyl-3,1-benzoxazin-4-one, 2-p-benzoyl Phenyl-3,1-benzoxazin-4-one, 2-p-methoxyphenyl-3,1-benzoxazin-4-one, 2-o-methoxyphenyl-3,1-benzoxazin-4-one, 2-cyclohexyl-3,1-benzoxazin-4-one, 2-p- (or m-) phthalimidophenyl-3,1-benzoxazin-4-one, N-phenyl-4- (3,1-benzo Oxazin-4-on-2-yl) phthalimide, N-benzoyl-4- (3,1-benzoxazin-4-on-2-yl) aniline, N-benzoyl-N-methyl-4- (3,1 -Benzoxazin-4-one-2-yl) aniline, 2- (p- (N-methylcarbonyl) phenyl) -3,1-benzoxazin-4-one, 2,2'-bis (3,1- Benzoxazin-4-one), 2,2′-ethylenebis (3,1-benzoxazin-4-one), 2,2′-tetramethylenebis (3,1-benzoxazin-4-one), 2 , 2'-Decame Tylene bis (3,1-benzoxazin-4-one, 2,2'-p-phenylenebis (3,1-benzoxazin-4-one), 2,2'-m-phenylenebis (3,1-benzo Oxazin-4-one), 2,2 ′-(4,4′-diphenylene) bis (3,1-benzoxazin-4-one), 2,2 ′-(2,6- or 1,5-naphthylene) ) Bis (3,1-benzoxazin-4-one), 2,2 ′-(2-methyl-p-phenylene) bis (3,1-benzoxazin-4-one), 2,2 ′-(2 -Nitro-p-phenylene) bis (3,1-benzoxazin-4-one), 2,2 '-(2-chloro-p-phenylene) bis (3,1-benzoxazin-4-one), 2 , 2 '-(1,4-cyclohexylene) bis (3,1-benzoo Sadin-4-one), 1,3,5-tri (3,1-benzoxazin-4-one-2-yl) benzene, 1,3,5-tri (3,1-benzoxazin-4-one) -2-yl) naphthalene, 2,4,6-tri (3,1-benzoxazin-4-one-2-yl) naphthalene, 2,8-dimethyl-4H, 6H-benzo (1,2-d; 5,4-d ′) bis (1,3) -oxazine-4,6-dione, 2,7-dimethyl-4H, 9H-benzo (1,2-d; 4,5-d ′) bis (1 , 3) -Oxazine-4,9-dione, 2,8-diphenyl-4H, 8H-benzo (1,2-d; 5,4-d ′) bis (1,3) -oxazine-4,6- Dione, 2,7-diphenyl-4H, 9H-benzo (1,2-d; 4,5-d ′) bis (1,3) -oxazine 4,6-dione, 6,6′-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-bis (2-ethyl-4H, 3,1-benzoxazine) -4-one), 6,6'-bis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6'-methylenebis (2-methyl-4H, 3,1-benzoxazine) -4-one), 6,6'-methylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6'-ethylenebis (2-methyl-4H, 3,1-benzo) Oxazin-4-one), 6,6′-ethylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6′-butylenebis (2-methyl-4H, 3,1- Benzoxazin-4-one), 6,6′-butylenebis (2 Phenyl-4H, 3,1-benzoxazin-4-one), 6,6′-oxybis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-oxybis (2- Phenyl-4H, 3,1-benzoxazin-4-one), 6,6′-sulfonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-sulfonylbis ( 2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6′-carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-carbonyl Bis (2-phenyl-4H, 3,1-benzoxazin-4-one), 7,7′-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′- Methylenebis (2-phenyl-4H , 3,1-benzoxazin-4-one), 7,7′-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-ethylenebis (2-methyl-) 4H, 3,1-benzoxazin-4-one), 7,7′-oxybis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-sulfonylbis (2-methyl) -4H, 3,1-benzoxazin-4-one), 7,7'-carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,7'-bis (2- Methyl-4H, 3,1-benzoxazin-4-one), 6,7′-bis (2-phenyl-4H, 3,1-benzoxazin-4-one, 6,7′-tylenebis (2-methyl) -4H, 3,1-benzoxazin-4-one, 6,7'-me Renbisu (2-phenyl-4H, 3,1-benzoxazin-4-one), and the like.

Among the above compounds, when the color tone is taken into consideration, a benzoxazinone-based compound that is difficult to be yellowed is preferably used, and examples thereof include those represented by the following formula (1). .

  In the above formula, R represents a divalent aromatic hydrocarbon group, and X1 and X2 are each independently selected from hydrogen or the following functional group group, but are not necessarily limited thereto.

  Functional group: alkyl group, aryl group, heteroaryl group, halogen, alkoxyl group, aryloxy group, hydroxyl group, carboxyl group, ester group, nitro group Among the compounds represented by the above structural formula, in the present invention, 2,2- (1,4-phenylene) bis [4H-3,1-benzoxazin-4-one] is particularly preferred.

  The polyester film constituting the double-sided coated film of the present invention usually contains an ultraviolet absorber in the range of 0.10 to 5.0% by weight, preferably 0.2 to 3.0% by weight. When the UV absorber is less than 0.10% by weight, the dye in the filter may be deteriorated by the UV light transmitted through the polyester film. When the UV absorber is contained in an amount exceeding 5.0% by weight May bleed out the ultraviolet absorber on the surface, leading to deterioration of surface functionality such as adhesion deterioration.

  As for the polyester film which comprises the double-sided coating film of this invention, 2.0% or less is preferable about the light transmittance of wavelength 380 nm, More preferably, it is 1.0% or less. When the light transmittance at a wavelength of 380 nm is larger than 2.0%, it may be difficult to cope with the necessity of ultraviolet absorption performance in outdoor use such as for building materials.

  Moreover, it is preferable that the total light transmittance of the double-sided coated film in the present invention is 90% or more in order to be able to cope with applications that particularly require transparency, and more preferably 92% or more. When the total light transmittance is less than 90%, the transparency becomes insufficient, and for example, it may be difficult to cope with applications that place importance on visibility, such as glass replacement.

  In addition to the above-mentioned particles, conventionally known antioxidants, antistatic agents, thermal stabilizers, lubricants, dyes, pigments, and the like can be added to the polyester film in the present invention as necessary.

  The thickness of the double-sided coating film constituting the polyester film laminate of the present invention is in a range capable of forming a film as a film, and needs to be 125 to 350 μm, preferably 188 to 300 μm.

  Next, although the manufacture example of the polyester film in this invention is demonstrated concretely, it is not limited to the following manufacture examples at all.

  First, a method of using the polyester raw material described above and cooling and solidifying a molten sheet extruded from a die with a cooling roll to obtain an unstretched sheet is preferable. In this case, in order to improve the flatness of the sheet, it is necessary to improve the adhesion between the sheet and the rotary cooling drum, and an electrostatic application adhesion method and / or a liquid application adhesion method are preferably employed. Next, the obtained unstretched sheet is stretched in the biaxial direction. In that case, first, the unstretched sheet is stretched in one direction by a roll or a tenter type stretching machine. The stretching temperature is usually 70 to 120 ° C., preferably 80 to 110 ° C., and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Subsequently, the extending | stretching temperature orthogonal to the 1st step | paragraph extending | stretching direction is 70-170 degreeC normally, and a draw ratio is 3.0-7 times normally, Preferably it is 3.5-6 times. Subsequently, heat treatment is performed at a temperature of 180 to 270 ° C. under tension or under relaxation within 30% to obtain a biaxially oriented film. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

  The simultaneous biaxial stretching method can also be adopted for the production of the polyester film in the present invention. The simultaneous biaxial stretching method is a method in which the unstretched sheet is usually stretched and oriented in the machine direction and the width direction at 70 to 120 ° C., preferably 80 to 110 ° C., and the stretching ratio is as follows: The area magnification is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Subsequently, heat treatment is performed at a temperature of 170 to 250 ° C. under tension or under relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, conventionally known stretching methods such as a screw method, a pantograph method, and a linear drive method can be employed.

  Furthermore, a so-called coating stretching method (in-line coating) in which the film surface is treated during the above-described polyester film stretching step can be applied. When a coating layer is provided on a polyester film by a coating stretching method, coating can be performed simultaneously with stretching and the thickness of the coating layer can be reduced according to the stretching ratio, producing a film suitable as a polyester film. it can.

  The coating layer constituting the double-sided coated film in the present invention has good adhesion to the hard coat layer, and also has a film haze even after wet heat treatment under high temperature and high humidity (for example, 85 ° C., 85% RH). It is preferable that the rise is as small as possible.

  It is preferable that the coating layer which comprises the laminated body of this invention has a coating layer formed from the coating liquid containing a 70 weight% or more crosslinking agent as a non-volatile component. The coating solution may contain other components as long as the gist of the present invention is not impaired.

  Various known crosslinking agents can be used as the crosslinking agent, and examples thereof include oxazoline compounds, melamine compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, and silane coupling compounds. Among these, especially when using for the use which provides a functional layer on a coating layer, an oxazoline compound is used suitably from a viewpoint that durable adhesiveness improves. Moreover, a melamine compound is used suitably from a viewpoint of prevention of precipitation of the ester cyclic trimer on the film surface by heating and improvement of durability and applicability of the coating layer.

  The oxazoline compound is a compound having an oxazoline group in the molecule, and a polymer containing an oxazoline group is particularly preferable, and can be prepared by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with another monomer. Addition polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be mentioned, and one or a mixture of two or more thereof can be used. Among these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially. The other monomer is not limited as long as it is a monomer copolymerizable with an addition polymerizable oxazoline group-containing monomer. For example, alkyl (meth) acrylate (the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, (meth) acrylic acid esters such as n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene Unsaturated carboxylic acids such as sulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); Unsaturated nitriles such as acrylonitrile, methacrylonitrile; (meth) acrylamide, N-alkyl ( (Meth) acrylamide, N, N-dialkyl (meth) acrylamide, As the alkyl group, unsaturated amides such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group and cyclohexyl group); vinyl acetate Vinyl esters such as vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride And α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like, and one or more of these monomers can be used.

  The amount of the oxazoline group of the oxazoline compound contained in the coating solution forming the coating layer constituting the double-sided coating film in the present invention is usually 0.5 to 10 mmol / g, preferably 3 to 9 mmol / g, more preferably 5 It is in the range of ˜8 mmol / g. By using it in the above range, the durability of the coating film is improved.

  The melamine compound is a compound having a melamine structure in the compound, for example, an alkylolated melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and these Mixtures can be used. As alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Moreover, as a melamine compound, either a monomer or a multimer more than a dimer may be sufficient, or a mixture thereof may be used. Further, a product obtained by co-condensing urea or the like with a part of melamine can be used, and a catalyst can be used to increase the reactivity of the melamine compound.

  The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include condensates of epichlorohydrin with ethylene glycol, polyethylene glycol, glycerin, polyglycerin, bisphenol A and the like hydroxyl groups and amino groups, There are polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, and the like. Examples of the polyepoxy compound include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane. Examples of the polyglycidyl ether and diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. , Polypropylene glycol diglycidyl ether, poly Examples of tetramethylene glycol diglycidyl ether and monoepoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and glycidyl amine compounds such as N, N, N ′, N′-tetraglycidyl-m-xylyl. Examples include range amine and 1,3-bis (N, N-diglycidylamino) cyclohexane.

  The isocyanate compound is a compound having an isocyanate derivative structure typified by isocyanate or blocked isocyanate. Examples of the isocyanate include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate, and aromatic rings such as α, α, α ′, α′-tetramethylxylylene diisocyanate. Aliphatic isocyanates such as aliphatic isocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), isopropylidene dicyclohexyl diisocyanate Ne Alicyclic isocyanates such as bets are exemplified. Further, polymers and derivatives such as burettes, isocyanurates, uretdiones, and carbodiimide modified products of these isocyanates are also included. These may be used alone or in combination. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

  When used in the state of blocked isocyanate, the blocking agent includes, for example, bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, and alcohols such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol. Compounds, active methylene compounds such as methyl isobutanoyl acetate, dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone, mercaptan compounds such as butyl mercaptan, dodecyl mercaptan, ε-caprolactam, δ-valerolactam, etc. Lactam compounds, amine compounds such as diphenylaniline, aniline, ethyleneimine, acetanilide, acid amide compounds of acetic acid amide, Examples include oxime compounds such as maldehyde, acetoald oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime, and these may be used alone or in combination of two or more.

  In addition, the isocyanate compound in the present invention may be used alone, or may be used as a mixture or bond with various polymers. In the sense of improving the dispersibility and crosslinkability of the isocyanate compound, it is preferable to use a mixture or a bond with a polyester resin or a urethane resin.

  A carbodiimide-based compound is a compound having a carbodiimide structure, and is a compound having one or more carbodiimide structures in the molecule, but for better adhesion, etc., the polycarbodiimide having two or more in the molecule More preferred are system compounds.

  The carbodiimide compound can be synthesized by a conventionally known technique, and generally a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and any of aromatic and aliphatic compounds can be used. Specifically, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexa Examples include methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

  The content of the carbodiimide group contained in the carbodiimide compound is carbodiimide equivalent (weight of the carbodiimide compound to give 1 mol of carbodiimide group [g]), and is usually 100 to 1000, preferably 250 to 700, more preferably 300. It is in the range of ~ 500. By using it in the above range, the durability of the coating film is improved.

  Furthermore, in order not to lose the effect of the present invention, in order to improve the water solubility and water dispersibility of the polycarbodiimide compound, adding a surfactant, polyalkylene oxide, quaternary ammonium salt of dialkylamino alcohol, You may add and use hydrophilic monomers, such as a hydroxyalkyl sulfonate.

  These cross-linking agents may be used singly or in combination of two or more kinds, but by combining two or more kinds, adhesion to the functional layer, which has been difficult to be compatible, and oligomer after heating (ester cyclic trimer) ) Was improved. Among them, a combination of an oxazoline compound that can improve adhesion to a functional layer and a melamine compound that is excellent in preventing precipitation of an oligomer (ester cyclic trimer) after heating is optimal and preferable.

  In addition, the present inventors have found that it is effective to combine three kinds of crosslinking agents in order to further improve the adhesion to the functional layer. As a combination of three or more kinds of cross-linking agents, it is preferable to select a melamine compound as one of the cross-linking agents. As a cross-linking agent to be combined with the melamine compound, an oxazoline compound, an epoxy compound, and a carbodiimide type are used. Particularly preferred are compounds and epoxy compounds.

  When such a crosslinking agent is contained, a component for promoting crosslinking at the same time, for example, a crosslinking catalyst can be used in combination.

  In addition, in the formation of the coating layer of the present invention, the binder polymer is used within the range that does not impair the gist of the present invention in order to improve the coating appearance and the adhesion when the functional layer is formed on the coating layer. It is also possible to use together.

  The binder polymer constituting the coating layer in the present invention is a number average molecular weight measured by gel permeation chromatography (GPC) according to a polymer compound safety evaluation flow scheme (sponsored by the Chemical Substance Council in November 1985). It is defined as a polymer compound having (Mn) of 1000 or more and having a film-forming property.

  Specific examples of the polymer include polyester resin, acrylic resin, urethane resin, polyvinyl (polyvinyl alcohol, etc.), polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, starches and the like. Among these, it is preferable to use a polyester resin, an acrylic resin, or a urethane resin from the viewpoint of improving adhesion with various surface functional layers. However, when the content increases, the precipitation prevention property of the ester cyclic trimer after heating may deteriorate, and it is usually 30% by weight or less, preferably 20% by weight or less, more preferably 10% by weight or less. When the ratio which occupies in a coating layer exceeds the said range, the precipitation inhibitory effect of the oligomer (ester cyclic trimer) after a heating may become inadequate.

  In addition, particles can be used in combination for the purpose of blocking and improving slipperiness in forming the coating layer. The average particle diameter is preferably 1.0 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.2 μm or less from the viewpoint of transparency of the film. Further, the lower limit is preferably 0.01 μm or more, more preferably 0.03 μm or more, and particularly preferably a range larger than the film thickness of the coating layer in order to improve the slipperiness more effectively. Specific examples of the particles include silica, alumina, kaolin, calcium carbonate, and organic particles.

  Further, in the range not impairing the gist of the present invention, an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, and an antioxidant are formed as necessary for forming the coating layer. It is also possible to use a foaming agent, a dye, a pigment and the like in combination.

  As a ratio with respect to all the non-volatile components in the coating liquid that forms the coating layer constituting the double-sided coating film in the present invention, the ratio of the crosslinking agent is preferably 70 wt% or more. More preferably, it is 80 weight% or more, Most preferably, it is 90 weight% or more. When the ratio of the crosslinking agent is less than 70% by weight, it may be difficult to suppress the precipitation of the oligomer (ester cyclic trimer) after heating the polyester film.

  From the viewpoint of preventing oligomer (ester cyclic trimer) precipitation after heat treatment, when melamine is selected as one of the crosslinking agents, the ratio of melamine as the ratio to the total nonvolatile components in the coating liquid forming the coating layer is: The range is usually from 5 to 95% by weight, preferably from 15 to 80% by weight, particularly preferably from 30 to 65% by weight. When the ratio of the crosslinking agent is out of the above range, precipitation suppression of the ester cyclic trimer after heating may be insufficient, or the coating appearance may be deteriorated.

  Further, the thickness (after drying) of the coating layer of the double-sided coating film is usually in the range of 0.003 to 1 μm, preferably 0.005 to 0.5 μm, more preferably 0.01 to 0.2 μm. It is. When the thickness is less than 0.003 μm, the amount of ester cyclic trimer precipitated from the film may not be sufficiently reduced. On the other hand, when the thickness is larger than 1 μm, there are cases where problems such as deterioration of the appearance of the coating layer and lowering of the blocking property may occur.

  Examples of methods for applying a coating solution to a polyester film include air doctor coating, blade coating, rod coating, bar coating, knife coating, squeeze coating, impregnation coating, reverse roll coating, transfer roll coating, gravure coating, and kiss roll coating. Conventional coating methods such as cast coating, spray coating, curtain coating, calendar coating, and extrusion coating can be used.

  In order to improve the coating property and adhesion of the coating agent to the film, the film may be subjected to chemical treatment, corona discharge treatment, plasma treatment or the like before coating.

  Analysis of various components in the coating layer can be performed by analysis of TOF-SIMS, ESCA, fluorescent X-rays, and the like.

  When providing a coating layer by in-line coating, the above-mentioned series of compounds is applied as an aqueous solution or dispersion, and the coating solution adjusted to a solid content concentration of about 0.1 to 50% by weight as a guide is applied onto the polyester film. It is preferable to produce a laminated polyester film. Moreover, in the range which does not impair the main point of this invention, a small amount of organic solvents may be contained in the coating liquid for the purpose of improving dispersibility in water, improving film-forming properties, and the like. Only one type of organic solvent may be used, or two or more types may be used as appropriate.

  In the present invention, the drying and curing conditions for forming the coating layer on the polyester film are not particularly limited. For example, when the coating layer is provided by off-line coating, it is usually 3 to 80 to 200 ° C. The heat treatment may be performed for 40 seconds, preferably 100 to 180 ° C. for 3 to 40 seconds.

  On the other hand, when the coating layer is provided by in-line coating, heat treatment is usually performed at 70 to 280 ° C. for 3 to 200 seconds as a guide.

  Further, irrespective of off-line coating or in-line coating, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination as required. The polyester film constituting the laminated polyester film in the present invention may be subjected to surface treatment such as corona treatment or plasma treatment in advance.

  About the plane orientation (ΔP) of the double-sided coated film thus obtained, it is an essential requirement to be in the range of 0.05 to 0.15 in order to improve the moldability after forming the laminate in the present invention. It is what. Regarding ΔP, this is preferably in the range of 0.05 to 0.13. When ΔP is less than 0.05, the moldability of the laminate is good. On the other hand, productivity such as frequent breakage is reduced during film formation, and it is not suitable as a component of the laminate. On the other hand, when ΔP exceeds 0.15, it becomes difficult for the laminate to obtain the desired moldability.

  In the double-sided coated film of the present invention, a surface functional layer such as a hard coat layer is generally provided on one coated layer. Although it does not specifically limit as a material used for a hard-coat layer, For example, hardened | cured materials, such as reactive silicon compounds, such as monofunctional (meth) acrylate, polyfunctional (meth) acrylate, and tetraethoxysilane, are mentioned. Among these, from the viewpoint of achieving both productivity and hardness, a polymerization cured product of a composition containing an ultraviolet curable polyfunctional (meth) acrylate is particularly preferable.

  It does not specifically limit as a composition containing a ultraviolet curable polyfunctional (meth) acrylate. For example, a mixture of one or more known ultraviolet curable polyfunctional (meth) acrylates, a commercially available UV curable hard coating agent, or other than these, in the range not impairing the purpose of the present embodiment, What added the other component further can be used.

  The UV-curable polyfunctional (meth) acrylate is not particularly limited. For example, dipentaerythritol hexa (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, tetramethylolmethanetri (meth) acrylate, (Meth) acryl derivatives of polyfunctional alcohols such as trimethylolpropane tri (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,6-bis (3-acryloyloxy-2-hydroxypropyloxy) hexane And polyethylene glycol di (meth) acrylate and urethane (meth) acrylate. From the viewpoint of moldability, it is preferable that urethane (meth) acrylate is a main component for the purpose of the present invention.

  Other components contained in the composition containing an ultraviolet curable polyfunctional (meth) acrylate are not particularly limited. Examples thereof include inorganic or organic fine particles, polymerization initiators, polymerization inhibitors, antioxidants, antistatic agents, dispersants, surfactants, light stabilizers and leveling agents. Moreover, when making it dry after film forming in the wet-coating method, arbitrary amounts of solvents can be added.

  As a method for forming the hard coat layer, when an organic material is used, a general wet coat method such as a roll coat method or a die coat method is employed. The formed hard coat layer can be subjected to a curing reaction by heating, irradiation with active energy rays such as ultraviolet rays and electron beams as necessary.

  The coating thickness of the hard coat layer (after drying) needs to be in the range of 2 to 100 μm in consideration of scratch resistance, impact resistance, and flexibility. The range is preferably 5 to 90 μm, more preferably 10 to 80 μm. When the coating thickness (after drying) is less than 2 μm, the scratch resistance and impact resistance are insufficient. On the other hand, when it exceeds 100 μm, the flexibility becomes insufficient.

  Further, the double-sided coated film may be subjected to surface treatment such as corona treatment or plasma treatment in advance.

  The film internal haze of the double-sided coated film thus obtained is preferably 0.6% or less, and more preferably 0.4% or less, when assuming substitute for glass, for example. When the said range exceeds 0.6%, when light is permeate | transmitted through a polyester film laminated body, defects, such as a poor visibility, will arise.

  In the present invention, for a double-sided coated film, as a specific method for keeping the film internal haze at 0.6% or less, for example, in the case of using a laminated polyester film in a double-sided coated film, It is possible to obtain a double-sided coating film having a higher degree of transparency by suppressing the particle content to substantially 0% and increasing the particle content while keeping the surface layer particle amount as thin as possible. This is preferable.

  Next, the adhesive layer which comprises the laminated body in this invention is demonstrated below. The pressure-sensitive adhesive layer in the present invention means a layer composed of an adhesive material, and conventionally known materials can be used as long as the gist of the present invention is not impaired. As one specific example, the case where an acrylic adhesive is used will be described below.

  In the present invention, the acrylic pressure-sensitive adhesive means a pressure-sensitive adhesive layer containing, as a base polymer, an acrylic polymer formed using an acrylic monomer as an essential monomer component. The acrylic polymer has (meth) acrylic acid alkyl ester and / or (meth) acrylic acid alkoxyalkyl ester having a linear or branched alkyl group as an essential monomer component (more preferably as a main monomer component). ) It is preferably an acrylic polymer to be formed. Further, the acrylic polymer is particularly preferably an acrylic polymer formed using (meth) acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester having a linear or branched alkyl group as essential monomer components. That is, the pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer formed using (meth) acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester having a linear or branched alkyl group as essential monomer components. It is particularly preferred.

In addition, the monomer component forming the acrylic polymer that is the base polymer in the pressure-sensitive adhesive layer of the present invention further contains a polar group-containing monomer, a polyfunctional monomer, and other copolymerizable monomers. It may be contained as a polymerization monomer component.

  In addition, said "(meth) acryl" represents "acryl" and / or "methacryl", and others are the same. Although not particularly limited, the content of the acrylic polymer as the base polymer in the pressure-sensitive adhesive layer of the present invention is preferably 60% by weight or more based on the total weight (100% by weight) of the pressure-sensitive adhesive layer. Preferably it is 80 weight% or more.

  As an essential monomer component for forming the acrylic polymer, a (meth) acrylic acid alkyl ester having a linear or branched alkyl group (hereinafter simply referred to as “(meth) acrylic acid alkyl ester”) may be used. ) Can be suitably used. Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth ) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate , Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) acrylic acid Isodecyl, undecyl (meth) acrylate, dodecyl (meth) acrylate, (Meth) acrylic acid tridecyl, (meth) acrylic acid tetradecyl, (meth) acrylic acid pentadecyl, (meth) acrylic acid hexadecyl, (meth) acrylic acid heptadecyl, (meth) acrylic acid octadecyl, (meth) acrylic acid nonadecyl, (meta ) (Meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group such as eicosyl acrylate. Moreover, the (meth) acrylic acid alkyl ester may be used alone or in combination of two or more. Among them, (meth) acrylic acid alkyl ester having 2 to 14 carbon atoms in the alkyl group is preferable, and (meth) acrylic acid alkyl ester having 2 to 10 carbon atoms in the alkyl group is more preferable. In particular, 2-ethylhexyl acrylate (2EHA) is preferable.

  Moreover, (meth) acrylic acid alkoxyalkyl ester [alkoxyalkyl (meth) acrylate] can also be suitably used as the essential monomer component (more preferably, the main monomer component) for forming the acrylic polymer. Particularly preferred is an acrylic acid alkoxyalkyl ester [alkoxyalkyl acrylate]. Although it does not specifically limit as (meth) acrylic-acid alkoxyalkylester, For example, (meth) acrylic-acid 2-methoxyethyl, (meth) acrylic-acid 2-ethoxyethyl, (meth) acrylic-acid methoxytriethylene glycol, (meta ) 3-methoxypropyl acrylate, 3-ethoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, 4-ethoxybutyl (meth) acrylate, and the like. The said (meth) acrylic-acid alkoxyalkylester can be used individually or in combination of 2 or more types. Among these, 2-methoxyethyl acrylate (2MEA) is preferable.

  In addition, the content of the essential monomer component [(meth) acrylic acid alkyl ester and / or (meth) acrylic acid alkoxyalkyl ester] forming the above acrylic polymer is selected from the viewpoint of adhesiveness of the pressure-sensitive adhesive layer. The amount is preferably 5% by weight or more (for example, 5 to 100% by weight), more preferably 5 to 95% by weight, based on the total amount (100% by weight) of monomer components forming the polymer. In addition, when both (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester are used as monomer components, the content of (meth) acrylic acid alkyl ester and (alkyl) alkoxyalkyl (meth) acrylate The total amount of ester content (total content) only needs to satisfy the above range.

  Among the above, it is preferable that both (meth) acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester are used as essential monomer components for forming the acrylic polymer. In that case, the content of the (meth) acrylic acid alkyl ester is preferably 5 to 95% by weight, more preferably 10 to 90% by weight, based on the total amount of monomer components (100% by weight) forming the acrylic polymer. %, More preferably 65-80% by weight, most preferably 65-75% by weight. If the content exceeds 95% by weight, the adhesiveness may decrease, and if it is less than 5% by weight, the elastic modulus of the pressure-sensitive adhesive layer may be too high. Further, the content of the alkoxyalkyl ester of acrylic acid is preferably 10 to 45% by weight, more preferably 10 to 40% by weight, and still more preferably with respect to the total amount (100% by weight) of monomer components forming the acrylic polymer. 20 to 35% by weight. If the content exceeds 45% by weight, the elastic modulus of the pressure-sensitive adhesive layer may be too high, and if it is less than 10% by weight, the adhesiveness may decrease.

  Examples of the polar group-containing monomer include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and other carboxyl group-containing monomers or anhydrides thereof (maleic anhydride, etc. ); Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate Hydroxyl group (hydroxyl group) -containing monomers such as vinyl alcohol and allyl alcohol; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-hydro Amide group-containing monomers such as ethyl acrylamide; Amino group-containing monomers such as aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate; ) Glycidyl group-containing monomers such as glycidyl acrylate and methyl glycidyl (meth) acrylate; Cyano group-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, (meth) acryloylmorpholine , N-vinyl pyridine, N-vinyl piperidone, N-vinyl pyrimidine, N-vinyl piperazine, N-vinyl pyrrole, N-vinyl imidazole, N-vinyl oxazole and other heterocyclic ring-containing vinyl monomers; sodium vinyl sulfonate, etc. Sulfonic acid group-containing monomer of 2-hydroxyethyl Chestnut phosphoric acid group-containing monomers such as acryloyl phosphate; cyclohexyl maleimide, imide group-containing monomers such as isopropyl maleimide; 2-methacryloyloxy such acryloyl isocyanate group-containing monomers such as methacryloyloxyethyl isocyanate. The said polar group containing monomer can be used individually or in combination of 2 or more types. Among the above-mentioned polar group-containing monomers, carboxyl group-containing monomers or acid anhydrides thereof, hydroxyl group-containing monomers, amino group-containing monomers, amide group-containing monomers, heterocyclic-containing vinyls Monomers are preferable, and acrylic acid (AA), 4-hydroxybutyl acrylate (4HBA), N-vinyl-2-pyrrolidone (NVP), and N-hydroxyethylacrylamide (HEAA) are particularly preferable.

  The content of the polar group-containing monomer is preferably 15% by weight or less with respect to 100% by weight of the monomer component forming the acrylic polymer. When it exceeds 15% by weight, the cohesive force of the pressure-sensitive adhesive layer becomes too high. As a result, the storage elastic modulus (23 ° C.) becomes too high, and the stress relaxation property may be lowered. If it is less than 0.01% by weight, the adhesion may be lowered.

  Among the above, the content of the hydroxyl group-containing monomer is preferably 5% by weight or less with respect to 100% by weight of the monomer component forming the acrylic polymer. When the content exceeds 5% by weight, the cohesive force of the pressure-sensitive adhesive layer becomes too high, the storage elastic modulus (23 ° C.) becomes too high, and the stress relaxation property may be lowered. Content of polar group-containing monomers other than hydroxyl group-containing monomers (particularly carboxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, heterocyclic-containing vinyl monomers) Is preferably 15% by weight or less with respect to 100% by weight of the monomer component forming the acrylic polymer. When the content exceeds 15% by weight, the cohesive force of the pressure-sensitive adhesive layer becomes too high, the storage elastic modulus (23 ° C.) becomes too high, and the stress relaxation property may be lowered.

  Examples of the polyfunctional monomer include hexanediol di (meth) acrylate, butanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, and (poly) propylene glycol di (meth) acrylate. , Neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methanetri (meth) ) Acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate and the like. The said polyfunctional monomer can be used individually or in combination of 2 or more types. Among the above, as the polyfunctional monomer, trimethylolpropane triacrylate (TMPTA) is preferable.

  The content of the polyfunctional monomer is preferably 0.5% by weight or less with respect to 100% by weight of the total amount of monomer components forming the acrylic polymer. When the content exceeds 0.5% by weight, for example, the cohesive force of the pressure-sensitive adhesive layer becomes too high, and the stress relaxation property may be lowered.

  Examples of copolymerizable monomers (other copolymerizable monomers) other than the above polar group-containing monomers and polyfunctional monomers include cyclopentyl (meth) acrylate and cyclohexyl (meth). (Meth) acrylates having an alicyclic hydrocarbon group such as acrylate and isobornyl (meth) acrylate, and (meth) acrylates having an aromatic hydrocarbon group such as phenyl (meth) acrylate and the like (meth ) (Meth) acrylic acid esters other than alkyl acrylates, alkoxyalkyl (meth) acrylates, polar group-containing monomers and polyfunctional monomers; vinyl esters such as vinyl acetate and vinyl propionate; styrene , Aromatic vinyl compounds such as vinyl toluene; ethylene, butadiene, isoprene, isobutylene, etc. Olefins or dienes; vinyl ethers such as vinyl alkyl ethers; and vinyl chloride.

  The acrylic polymer can be prepared by polymerizing the above monomer components by a conventionally known or conventional polymerization method. Examples of the polymerization method of the acrylic polymer include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method by active energy ray irradiation (active energy ray polymerization method). Among them, the solution polymerization method and the active energy ray polymerization method are preferable in terms of transparency, water resistance, production cost and the like, and particularly when forming a relatively thick pressure-sensitive adhesive layer, active energy ray polymerization (photopolymerization and Method), and an ultraviolet polymerization method by ultraviolet irradiation is particularly preferable.

  Examples of the active energy rays irradiated in the above active energy ray polymerization (photopolymerization) include ionizing radiation such as α rays, β rays, γ rays, neutron rays, electron rays, and ultraviolet rays, among others. Ultraviolet rays are suitable for the use of the present invention. Further, the irradiation energy, irradiation time, irradiation method, and the like of the active energy ray are not particularly limited as long as they do not impair the gist of the present invention.

  In the solution polymerization, various common solvents can be used. Examples of such solvents include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane and methylcyclohexane Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. A solvent can be used individually or in combination of 2 or more types.

  In preparing the acrylic polymer, a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) can be used depending on the type of polymerization reaction. A polymerization initiator can be used individually or in combination of 2 or more types.

  The photopolymerization initiator is not particularly limited. For example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photo An active oxime photopolymerization initiator, a benzoin photopolymerization initiator, a benzyl photopolymerization initiator, a benzophenone photopolymerization initiator, a ketal photopolymerization initiator, a thioxanthone photopolymerization initiator, and the like can be used. The amount of the photopolymerization initiator used is not particularly limited, but is preferably in the range of 0.01 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of monomer components forming the acrylic polymer.

  Specific examples of the benzoin ether photopolymerization initiator include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one. And anisole methyl ether. Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4- (t-butyl). Examples include dichloroacetophenone. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one. . Specific examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime. Examples of the benzoin photopolymerization initiator include benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Specific examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Specific examples of the ketal photopolymerization initiator include benzyldimethyl ketal. Specific examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, and the like.

  Specific examples of the thermal polymerization initiator include azo polymerization initiators [for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis. (2-methylpropionic acid) dimethyl, 4,4′-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [ 2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-di) Methyleneisobutylamidine) dihydrochloride], peroxide-based polymerization initiators (eg, dibenzoyl peroxide, tert-butylpermaleate, etc.), redox Scan type polymerization initiators and the like. The amount of the thermal polymerization initiator used is not particularly limited as long as it does not impair the gist of the present invention, and may be any range that can be conventionally used as a thermal polymerization initiator.

  In the pressure-sensitive adhesive layer of the present invention, a cross-linking agent, a cross-linking accelerator, a tackifier (for example, rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin, etc.), anti-aging agent, filler, as necessary , Colorants (pigments, dyes, etc.), UV absorbers, antioxidants, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, etc., as necessary, as long as they do not impair the properties of the present invention. Can be used.

  The said crosslinking agent can control the gel fraction of an adhesive layer by bridge | crosslinking the base polymer of an adhesive layer. As crosslinking agents, isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents Agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents, and the like, and isocyanate crosslinking agents and epoxy crosslinking agents can be preferably used. A crosslinking agent can be used individually or in combination of 2 or more types.

  The pressure-sensitive adhesive layer thickness (after drying) of the laminate in the present invention is usually in the range of 25 to 200 μm, preferably in the range of 25 μm to 100 μm. When the thickness of the pressure-sensitive adhesive layer is 25 μm or less, it may be difficult to obtain a desired adhesive force. On the other hand, when the thickness of the pressure-sensitive adhesive layer exceeds 200 μm, curing of the pressure-sensitive adhesive layer becomes insufficient, and problems such as deterioration in workability may occur.

  The laminated body thus obtained requires a high degree of transparency even after being exposed to a high temperature atmosphere for a long time, for example, for a touch panel. From this viewpoint, the total light transmittance of the laminate needs to be 90% or more. The total light transmittance is preferably 92% or more. When the total light transmittance of the laminated body is less than 90%, the visibility becomes insufficient, and for example, it becomes difficult to apply the curved glass to an alternative use. Furthermore, the film haze in the laminate is preferably 1.5% or less, more preferably 1.3% or less. If the film haze is less than 1.5%, for example, it may be difficult to apply to applications that require a high degree of visibility, such as glass replacement applications.

  In addition, in the laminate, in consideration of application to electronic parts, the film haze change amount (ΔH) before and after wet heat treatment at 85 ° C. and 85% RH for 100 hours is 1.5% or less. There must be. ΔH is preferably 0.7% or less, and more preferably 0.3% or less. When ΔH exceeds 1.5%, the visibility decreases as the film haze rises due to the precipitation of the oligomer (ester cyclic trimer), and high visibility is required, for example, for touch panels. It becomes difficult to cope with optical applications.

  The film thickness of the laminate in the present invention is preferably in the range of 300 to 900 μm in consideration of impact resistance and handleability. More preferably, the range of 400-700 micrometers is good. When the film thickness is less than 300 μm, the impact resistance may be insufficient. On the other hand, when the film thickness exceeds 900 μm, problems such as deterioration in workability during handling may occur.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded. The measuring method used in the present invention is as follows.

(1) Measurement of intrinsic viscosity (dl / g) of polyester 1 g of polyester from which other polymer components and pigments incompatible with polyester have been removed are precisely weighed and mixed with phenol / tetrachloroethane = 50/50 (weight ratio). 100 ml of solvent was added and dissolved, and measurement was performed at 30 ° C.

(2) Average particle diameter (d50)
The average particle size d50 was defined as the particle size having an integrated volume fraction of 50% in an equivalent spherical distribution measured using a centrifugal sedimentation type particle size distribution analyzer (SA-CP3 type) manufactured by Shimadzu Corporation.

(3) Measurement of haze inside film of polyester film Using sample film, glass product filled with ethanol solution using haze meter device (model: HZ-2) manufactured by Suga Test Co., Ltd. based on JIS-K-7136. The haze value of the cell was set to 0%, and the haze value inside the film was measured in a state where the test piece of the sample film was immersed in the cell.

(4) Measurement of film haze The film haze of the measurement sample film (and laminate) was measured with a haze meter “HM-150” manufactured by Murakami Color Research Laboratory Co., Ltd. according to JIS-K-7136.

(5) Thickness variation of film Using a sample film, a continuous tape-shaped sample having a length of 3 m in the transverse stretching direction and 5 cm in the longitudinal stretching direction is wound up, and the film thickness is continuously measured by an Anritsu Co., Ltd. Measure film thickness and record on recorder. From the chart, the maximum value (dmax), the minimum value (dmin), and the average value (d) of the thickness were obtained, and the thickness unevenness (%) was calculated by the following formula. In addition, when the length of a horizontal extending direction is less than 3 m, it joins and performs. The connected part is excluded from the data analysis. The measurement was performed 3 times, the average value was calculated | required, and it determined by the following criteria.
Thickness unevenness (%) = ((dmax−dmin) / d) × 100
(Criteria)
○: Thickness unevenness is 3% or less ×: Thickness unevenness exceeds 3%

(6) Plane orientation coefficient (ΔP)
Using a sample film, according to JIS K 7142-1996 5.1 (Method A), using a sodium D line as a light source, the Abbe refractometer uses a film longitudinal direction refractive index (nx), a width direction refractive index (ny), The refractive index (nz) in the thickness direction was measured, and the plane orientation coefficient (ΔP) was calculated by the following formula.
ΔP = (nx + ny) / 2−nz

(7) Measurement of rate of change in film haze (ΔH) before and after wet heat treatment (practical property substitution evaluation)
In each laminate obtained in the examples and comparative examples, the film haze was measured by the method of (4) after being left in a constant temperature and humidity chamber at 85 ° C. and 85% RH atmosphere for 100 hours. 1). ΔH was calculated with a difference from the untreated film haze (haze 2) of the same sample.
ΔH = (haze 1) − (haze 2)
The lower ΔH, the less oligomer precipitation due to the wet heat treatment, which is better. (Criteria)
◎: ΔH is 0.3% or less, particularly good visibility ○: ΔH is over 0.3% and 0.7% or less, and △: ΔH is over 0.7%, 1 .5% or less (may be problematic in practice) ×: ΔH exceeds 1.5% (practical problem level)

(8) Adhesive evaluation of hard coat layer Using the hard coat layer surface of the obtained laminate, 100 grid-shaped cuts were made using a cutter guide with a gap interval of 1 mm. Next, an 18 mm wide tape (Cello Tape (registered trademark) CT-18 manufactured by Nichiban Co., Ltd.) was applied to the cut surface on the grid, and the 2.0 kg roller was reciprocated 20 times to completely adhere to it. The peeled surface after peeling off rapidly at the peeling angle was observed and judged according to the following criteria.
(Criteria)
A: Peeling area is less than 5% B: Peeling area is 5% or more and less than 20% B: Peeling area is 20% or more and less than 50% X: Peeling area is 50% or more

(9) Foreign body detectability evaluation of laminate (practical property substitution evaluation)
During the production of each laminate of Examples and Comparative Examples, black metal powder (foreign matter) having a size of 50 μm or more was mixed at 50 / m ² during the production of the pressure-sensitive adhesive composition to produce a laminate. Next, with each of the first double-sided coated film side and the second double-sided coated film side of the obtained laminate, a pressure sensitive adhesive is used with a digital microscope (model: KH-7700) manufactured by HIROX in the state of being bonded. The layer was observed for foreign matter and judged according to the following criteria.
(Criteria)
○: Foreign body inspection in the pressure-sensitive adhesive layer is possible with the laminate structure, and inspection is easy (at a level where there is no practical problem)
×: It is difficult to inspect the foreign material of the pressure-sensitive adhesive layer with a laminate structure (practically problematic level)

(10) Evaluation of visibility of laminate after wet heat treatment (substitute evaluation of oligomer sealing property)
The following judgment is made on whether or not the adhesive layer can be observed in the laminated state after being left in an atmosphere of 85 ° C. and 85% RH for 100 hours in a thermostat using each of the laminated bodies of Examples and Comparative Examples. Judgment was made according to the criteria.
(Criteria)
○: It is possible to inspect the pressure-sensitive adhesive layer with a laminate structure, and it is easy to inspect (practically no problem level)
×: Since the film haze is increased, it is difficult to inspect the adhesive layer with the laminate structure (practically problematic level)

(11) Evaluation of scratch resistance on surface of hard coat layer of laminate (practical property substitution evaluation)
Taihei Rika Kogyo's exclusive jig (5cm x 7cm, 500g) is wrapped with sheet-like cotton (Bencot made by Asahi Kasei Co., Ltd.), and the hard coat layer surface of the first hard coat film and the second hard coat film is reciprocated 30 times (15cm length) Range). Thereafter, the rubbed portion was visually observed under a three-wavelength fluorescent lamp, and judged according to the following criteria.
(Criteria)
○: Scratch occurrence frequency is 3 or less ×: Scratch occurrence frequency exceeds 3 ○ ○ is a level that is not a problem in practical use

(12) Curling evaluation of laminate (practical property substitution evaluation)
After cutting out the laminated body so that one piece becomes a square of 10 cm to obtain a measurement sample, the sample is heat-treated in a hot air circulating furnace set at 150 ° C. for 60 minutes. Next, the sample was placed on a horizontal base, the heights of the four corners floating from the horizontal plane were measured, and this average value was taken as the curl value.
(Criteria)
○: Curl value is 3 mm or less (practically no problem level)
X: Curling value exceeds 3 mm (practically problematic level)
By performing the laminate planarity evaluation after the heat treatment based on the above determination, a more accurate film laminate can be obtained.

(13) Evaluation of UV absorption performance of laminate (practical property substitution evaluation)
Using the laminate, the light transmittance was continuously measured with a spectrophotometer (UV-3100PC type manufactured by Shimadzu Corporation) at a low scanning speed, a sampling pitch of 2 nm, and a wavelength range of 300 to 700 nm. The light transmittance at the wavelength was measured.

(14) Flexibility evaluation of laminates (practical property substitution evaluation)
The laminate was evaluated by wrapping around a cylinder having a diameter of 80 mm, and after wrapping, the hard coat layer was observed for cracks and peeling, and judged according to the following criteria.
(Criteria)
○: There is no crack or peeling of the hard coat layer (a level that is practically acceptable)
X: Cracks and peeling of the hard coat layer are observed (practically problematic level)

(15) Impact resistance evaluation of laminate (practical property substitution evaluation)
Based on JIS K 5600-5-3, a DuPont impact tester equipped with a ¼ inch iron ball was used. A test film laminate was placed on a sample stage and a weight of 500 g was dropped from a height of 50 cm, and then the surface of the hard coat layer of the test piece was observed and judged according to the following criteria.
(Criteria)
○: Slight whitening is confirmed on the surface of the hard coat layer (a level with no problem in practical use)
Δ: A minute crack is confirmed on the surface of the hard coat layer (a level that may cause a problem in practical use)
X: Cracks are confirmed on the hard coat layer surface (practically problematic level)

(16) Formability evaluation of laminate (practical property substitution evaluation)
Examples and comparative examples on the surface of three types of SUS molds having a width of 7 cm, a length of 14 cm, a height of 2 cm, and R (curvature radii) of 5 mm, 10 mm, and 15 mm, respectively, using a laminate. The laminates obtained in 1 were bonded together, and a SUS mold (thickness 5 mm) was attached so as to cover the surface of the laminate. Next, heat and pressure molding was performed under the pressure of 20 kg / cm ² at 120 ° C. for 15 minutes with the concavo-convex mold attached through the laminate. Each laminated body taken out was determined according to the following criteria.
(Criteria)
○: The moldability is good, the shape is not restored even after 24 hours have passed after the laminate is molded, and the shape after the molding is maintained (practically no problem level)
Δ: Good formability, and after 24 hours from forming the laminate, the shape tends to be slightly restored, but it is a practically no problem level. Does not follow the laminate, or after forming the laminate 24 hours later, it will be restored to the shape before molding, or cracks will occur in the hard coat layer on the laminate surface (practically problematic level)

(17) Comprehensive evaluation (practical property substitution evaluation)
Using the laminates produced in the examples and comparative examples, visibility after wet heat treatment, foreign matter detection, hard coat adhesion, impact resistance, flexibility, curl, moldability, scratch resistance The evaluation items were comprehensively evaluated according to the following criteria.
(Criteria)
○: Visibility after wet heat treatment, foreign matter detection, hard coat adhesion, impact resistance, flexibility, curl, moldability, scratch resistance are all ○ (practically no problem level)
△: At least one of visibility after wet heat treatment, foreign matter detection, hard coat adhesion, impact resistance, flexibility, curling, moldability, and scratch resistance is △ (in case of practical problems) There is a level)
×: At least one of visibility after wet heat treatment, foreign matter detection property, hard coat adhesion, impact resistance, flexibility, curling property, moldability, and scratch resistance is × (a practically problematic level).

The polyester used in the examples and comparative examples was prepared as follows.
<Manufacture of polyester>
Production Example 1 (Polyester A1)
100 parts of dimethyl terephthalate, 60 parts of ethylene glycol and 0.09 part of magnesium acetate tetrahydrate are placed in a reactor, the temperature is raised by heating, methanol is distilled off, transesterification is performed, and 4 hours are required from the start of the reaction. The temperature was raised to 230 ° C. to substantially complete the transesterification reaction. Next, after adding 0.04 part of ethylene glycol slurry ethyl acid phosphate and 0.03 part of antimony trioxide, the temperature reached 280 ° C. and the pressure reached 15 mmHg in 100 minutes. It was 0.3 mmHg. After 4 hours, the system was returned to normal pressure to obtain polyester A1 having an intrinsic viscosity of 0.61 (dl / g).

Production Example 2 (Polyester A2)
In the method for producing polyester (A1), polyester (A1) was added except that after adding ethyl acid phosphate, silica particles having an average particle size of 2.3 μm were added so that the content with respect to polyester was 0.3% by weight. ) Was used to obtain polyester A2 having an intrinsic viscosity of 0.62 (dl / g).

Production Example 3 (Polyester A3)
Polyester (A1) was subjected to a twin screw extruder with a vent, and 2,2- (1,4-phenylene) bis [4H-3,1-benzoxazin-4-one] (manufactured by CY TEC Co., Ltd.) as an ultraviolet absorber. CYASORB UV-3638 (molecular weight 369 benzoxazinone type) was supplied to a concentration of 10% by weight and melt-kneaded to form chips, and an ultraviolet absorbent master batch polyester (A3) was produced. The intrinsic viscosity of the obtained polyester (A5) was 0.59 (dl / g).

Production Example 4 (Polyester A4)
The starting material is 100 parts by weight of dimethyl terephthalate, 54 parts by weight of ethylene glycol and 25 parts by weight of 1,4-cyclohexanedimethanol, 0.011 part by weight of tetrabutyl titanate is used as a catalyst, and the reaction start temperature is 150 ° C. The reaction temperature was gradually increased with the distillation of methanol, and the temperature was raised to 230 ° C. after 3 hours, and the reaction was continued for another hour. Thereafter, the temperature was gradually raised from 230 ° C. and the pressure was gradually reduced from the normal pressure, and finally the temperature was 280 ° C. and the pressure was 0.3 mmHg. After the start of the reaction, the reaction was stopped at a time corresponding to an intrinsic viscosity of 0.68 (dl / g) due to a change in stirring power of the reaction tank, and the polymer was discharged under nitrogen pressure. The intrinsic viscosity of the obtained polyester (A4) was 0.68 (dl / g), and the content of 1,4-cyclohexanedimethanol (hereinafter sometimes abbreviated as CHDM) was 33 mol%.

Production Example 5 (Polyester A5)
Isophthalic acid and terephthalic acid were used as the dicarboxylic acid component, and ethylene glycol was used as the polyhydric alcohol component, respectively, and those produced by the usual melt polycondensation method were used.
In the dicarboxylic acid component of this raw material, the content of isophthalic acid (hereinafter sometimes abbreviated as IPA) was 22 mol%.

Production Example 6 (Production of polyester film F1)
Polyester A1, A2, and A5 are blended in proportions of 20%, 10%, and 70%, respectively, as surface layer materials, and polyesters A1, A3, A4, and A5 are 40%, 2%, 28%, and 30% materials. The raw material for the intermediate layer is supplied to two vented extruders, melt-extruded at 290 ° C., and then cooled and solidified on a cooling roll set at a surface temperature of 40 ° C. using an electrostatic application adhesion method. An amorphous film having a thickness of about 3000 μm was obtained. This film was stretched 3.1 times in the machine direction at 85 ° C. Thereafter, a coating layer comprising the following coating solution was applied on both sides so that the coating thickness (after drying) was 0.04 g / m 2, the film was guided to a tenter, and stretched 3.8 times in the transverse direction at 110 ° C. And a heat treatment at 185 ° C. to obtain a polyester film F1 having a thickness of 250 μm (thickness ratio = 7 μm / 236 μm / 7 μm).

Moreover, the following was used as a composition contained in a coating liquid.
(A1): Hexamethoxymethylolmelamine (A2): Epocross which is an oxazoline compound (manufactured by Nippon Shokubai Co., Ltd.) Oxazoline group amount 7.7 mmol / g
(A3): Epocross which is an oxazoline compound (manufactured by Nippon Shokubai Co., Ltd.) Oxazoline group amount 4.5 mmol / g
(A4): Polyglycerol polyglycidyl ether (A5): Block polyisocyanate synthesized by the following method

1000 parts of hexamethylene diisocyanate was stirred at 60 ° C., and 0.1 part of tetramethylammonium capryate was added as a catalyst. After 4 hours, 0.2 part of phosphoric acid was added to stop the reaction, and an isocyanurate type polyisocyanate composition was obtained. 100 parts of the obtained isocyanurate type polyisocyanate composition, 42.3 parts of methoxypolyethylene glycol having a number average molecular weight of 400, and 29.5 parts of propylene glycol monomethyl ether acetate were charged and maintained at 80 ° C. for 7 hours. Thereafter, the reaction solution temperature was kept at 60 ° C., 35.8 parts of methyl isobutanoyl acetate, 32.2 parts of diethyl malonate, and 0.88 part of 28% methanol solution of sodium methoxide were added and kept for 4 hours. Block polyisocyanate (A6) obtained by adding 58.9 parts of n-butanol and maintaining the reaction liquid temperature at 80 ° C. for 2 hours and then adding 0.86 part of 2-ethylhexyl acid phosphate: polycarbodiimide system Carbodilite (manufactured by Nisshinbo Chemical Co., Ltd.), a compound. Carbodiimide equivalent 340
(B1): Acrylic resin aqueous dispersion polymerized with the following composition and having a glass transition point of 40 ° C. Ethyl acrylate / n-butyl acrylate / methyl methacrylate / N-methylol acrylamide / acrylic acid = 65/21/10/2 / 2 (% by weight) emulsion polymer (emulsifier: anionic surfactant)
(B2): 315 parts by weight of terephthalic acid, 299 parts by weight of isophthalic acid, 74 parts by weight of ethylene glycol, and 265 parts by weight of diethylene glycol as the component (B2a), (B2a) 953 parts by weight, isophorone diisocyanate Polyester polyurethane comprising 267 parts by weight, ethylene glycol 56 parts by weight, and dimethylolpropionic acid 67 parts by weight neutralized with ammonia and dispersed in water (concentration 23%, viscosity at 25 ° C., 30 mPa · s) )
(C1): 2-amino-2-methylpropanol hydrochloride (F1) which is a melamine crosslinking catalyst: silica particles having an average particle size of 0.07 μm

Production Example 7 (Production of Polyester Film F2) to Production Example 39 (Production of Polyester Film F34)
In Production Example 6, a polyester film was obtained in the same manner as in Production Example 6 except that the type, thickness, blending ratio of raw materials, type of coating layer, and heat setting temperature were different.
Example 1:

Polyester film F1 was used as the first double-sided coated film, and polyester film F1 was used as the second double-sided coated film. On one coating layer of the polyester film F1, a hard coat layer composed of the following hard coat agent composition was applied and dried so that the coating thickness (after drying) was 30 μm to obtain a hard coat film. On one surface of the coating layer, a coating agent having the following coating composition was applied so that the thickness after curing was 10 μm, and dried in a hot air drying oven set at 80 ° C. for 1 minute. Next, using a high-pressure mercury lamp having an energy of 120 W / cm, curing was performed at 300 mJ / cm ² at an irradiation distance of 50 mm to obtain a hard coat film having an active energy ray-curable resin layer provided on the film.
<< Coating composition >>
Nippon Gohsei Kagaku Kogyo Co., Ltd., Shikomi 7650B (containing urethane acrylate) and Ciba Specialty Chemicals Co., Ltd. Irgacure 651 were mixed at a weight ratio of 100/5 and diluted with methyl ethyl ketone to a concentration of 30% by weight.
<Manufacture of laminates>
The release film (light release) was peeled off from the coating layer surface of the obtained second hard coat film, and a pressure-sensitive adhesive sheet composed of the following acrylic pressure-sensitive adhesive composition was bonded thereto. Next, the release film (heavy release) was peeled off, and the coating layer surface of the first hard coat film was bonded to the exposed adhesive sheet surface to obtain a laminate.

In addition, the adhesive sheet to be used was previously stored in the configuration of an optical transparent adhesive sheet (OCA: Optical Clear Adhesive) shown below. Specifically, a coating solution comprising the following pressure-sensitive adhesive layer forming composition is applied to the surface of the release layer of a heavy release type release film (Diafoil MRV75 (V08) manufactured by Mitsubishi Plastics), and then heat treated at 100 ° C. for 5 minutes. Thus, an adhesive layer having a coating amount (after drying) of 25 μm was obtained. Then, a light release type release film (Mitsubishi Resin Diafoil MRE38) is bonded to the exposed adhesive layer surface, and OCA is composed of release film (light release) / adhesive layer / release film (heavy release). Got.
<Acrylic pressure-sensitive adhesive layer forming composition>
(Monomer composition)
2-ethylhexyl acrylate 70% by weight
2-methoxyethyl acrylate 29% by weight
4-hydroxybutyl acrylate 1% by weight
0.1 part of Nippon Polyurethane Coronate L was added to 100 parts by weight of the monomer composition to obtain an acrylic pressure-sensitive adhesive layer forming composition.

Examples 2-28:
In Example 1, it manufactured like Example 1 except changing the coating liquid composition, the combination of a polyester film, and the application thickness (after drying) of a hard-coat layer, and obtained the layered product. Comparative Example 1:
In Example 1, it manufactured similarly to Example 1 except having changed the polyester film F1 into the polyester film F29 (a coating layer is not provided in both surfaces), and obtained the laminated body.

Comparative Example 2:
In Example 1, it manufactured like Example 1 except having changed the application thickness (after drying) of a hard-coat layer into 110 micrometers, and obtained the layered product.

Comparative Example 3:
In Example 1, it manufactured like Example 1 except having changed the application thickness (after drying) of a hard-coat layer into 1 micrometer, and obtained the laminated body.

Comparative Example 4:
In Example 1, it manufactured like Example 1 except providing a hard-coat layer only on one exposed coating layer, and obtained the polyester film laminated body. The obtained laminate was curled more largely in the curl evaluation, probably due to the asymmetric structure centered on the adhesive layer.
Comparative Example 5:
In Example 1, it manufactured similarly to Example 1 except having changed the polyester film F1 into the polyester film F27, and obtained the laminated body. Since film crystallization progressed at the stage of forming the polyester film F27 and the film haze increased, the film was used as a constituent member, so that it was difficult to apply for glass replacement.

Comparative Examples 6-8:
In Example 1, it manufactured like Example 1 except changing the kind of coating layer, and obtained the layered product.

Comparative Example 9:
In Example 1, it manufactured like Example 1 except having changed the polyester film F1 into the polyester film F28, and obtained the laminated body.

Comparative Example 10:
In Example 1, it manufactured similarly to Example 1 except having changed the polyester film F1 into the polyester film F30, and obtained the laminated body. In the obtained laminate, since the polyester film F30 having a large thickness unevenness was used, curling was likely to be large, and it was difficult to apply for glass replacement.

Comparative Example 11:
In Example 1, it manufactured similarly to Example 1 except having changed the polyester film F1 into the polyester film F31, and obtained the laminated body.
The characteristics of the laminates obtained in the examples and comparative examples are summarized in Tables 1 to 9 below.

The present invention relates to a laminate, and more specifically, in various fields such as in-vehicle use, building material use, optical use, for example, display surface protection, and the like, particularly for the purpose of replacing curved glass, and has excellent scratch resistance and flexibility. Provided is a laminate having a hard surface with high hardness and good visibility after wet heat treatment, foreign matter detection, hard coat adhesion, impact resistance, curling properties, and moldability.

DESCRIPTION OF SYMBOLS 10 Laminated body 11 Adhesive layer 31 1st hard coat film 13 Hard coat layer 14 Application layer 15 1st polyester film base material 16 Application layer 32 2nd hard coat film 22 Hard coat layer 23 Application layer 24 2nd polyester film base material 25 Coating layer

Claims (2)

The surface orientation (ΔP) is 0.05 to 0.15, the thickness is 125 to 350 μm, the polyester film having the coating layer on both sides is provided on both sides of the pressure-sensitive adhesive layer, and the thickness ( (After drying) is a laminate having a hard coat layer of 2 to 100 μm, and the laminate has a total light transmittance of 90% or more, and is laminated before and after wet heat treatment for 100 hours in an atmosphere of 85 ° C. and 85% RH. A laminate having a film haze change rate (ΔH) of 1.5% or less. The laminate according to claim 1, wherein the coating layer on the pressure-sensitive adhesive layer surface side is formed from a coating solution containing 70% by weight or more of a crosslinking agent as a nonvolatile component.