JP2015199225A - Laminated polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate polyester film capable of being suitably used for various applications requiring a high quality active energy ray-curable resin layer with less defect, e.g. a transparent electrode or a film member for molding for a touch panel.SOLUTION: There is provided a laminate polyester film having a coating layer containing 10 wt.% of particles having an average particle diameter of 0.10 to 1.0 μm and an active energy ray-curable resin layer on the coating layer on at least a single face of a polyester film.

Description

  The present invention relates to a laminated polyester film, for example, a laminated polyester film having an active energy ray-curable resin layer such as a hard coat layer, such as a transparent electrode such as a touch panel or a film for molding.

  In recent years, polyester films are often used for various optical films and molding films. Transparent electrodes such as touch panels, which are members of various displays, antireflection films, prism sheets, light diffusion sheets, electromagnetic wave shielding films, It is used for applications such as mold transfer films and in-mold label films. The base film used for these members is required to have excellent transparency and visibility.

  Therefore, the film used for these uses generally has high transparency. However, in order to increase transparency, a flat film design is used. For this reason, the slipperiness of the film is poor, scratches and wrinkles occur in the processing process, and it may be difficult to manufacture a high-quality processed product. In addition, because of the high transparency, it is not easy to distinguish between the processed film on which the active energy ray-curable resin layer is formed and the unprocessed film before processing, and in particular, a single wafer form Sometimes there is a possibility of mistakes between processed and unprocessed products.

JP 2005-97571 A

  The present invention has been made in view of the above circumstances, and the solution is to use an active energy ray-curable resin layer such as a hard coat layer with few defects by using a film with high processing characteristics, For example, it is providing the laminated polyester film which can be utilized suitably as members, such as a touchscreen by which high quality is calculated | required.

  As a result of intensive studies in view of the above circumstances, the present inventors have found that the use of a laminated polyester film having a specific configuration can easily solve the above-described problems, and have completed the present invention.

  That is, the gist of the present invention is that at least one side of a polyester film has a coating layer containing 10% by weight or more of particles having an average particle size of 0.10 to 1.0 μm, and active energy ray curing is performed on the coating layer. It exists in the laminated polyester film characterized by having a conductive resin layer.

  According to the laminated polyester film of the present invention, a high-quality laminated polyester film with few defects can be provided, and its industrial value is high.

  The polyester film constituting the laminated polyester film in the present invention may have a single layer structure or a multilayer structure, and may have four or more layers as long as it does not exceed the gist of the present invention other than a two-layer or three-layer structure. It may be a multilayer, and is not particularly limited.

  The polyester used 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. Typical polyester includes polyethylene terephthalate and the like. On the other hand, the dicarboxylic acid component of the copolyester includes isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, p-oxybenzoic acid, etc.), etc. 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, 4-cyclohexane dimethanol, neopentyl glycol, is mentioned.

  There is no restriction | limiting in particular as a polymerization catalyst of polyester, A conventionally well-known compound can be used, For example, an antimony compound, a titanium compound, a germanium compound, a manganese compound, an aluminum compound, a magnesium compound, a calcium compound etc. are mentioned. Among these, titanium compounds and germanium compounds are preferable because they have high catalytic activity, can be polymerized in a small amount, and the amount of metal remaining in the film is small, so that the brightness of the film becomes high. Furthermore, since a germanium compound is expensive, it is more preferable to use a titanium compound.

  In the case of polyester using a titanium compound, the titanium element content is preferably 50 ppm or less, more preferably 1 to 20 ppm, and still more preferably 2 to 10 ppm. If the content of the titanium compound is too high, the polyester may be deteriorated in the process of melt-extruding the polyester, resulting in a strong yellowish film. If the content is too low, the polymerization efficiency is poor and the cost is low. In some cases, a film having a sufficient strength or a sufficient strength cannot be obtained. Moreover, when using the polyester by a titanium compound, it is preferable to use a phosphorus compound in order to reduce the activity of a titanium compound for the purpose of suppressing deterioration in the step of melt extrusion. As the phosphorus compound, orthophosphoric acid is preferable in view of the productivity and thermal stability of the polyester. The phosphorus element content is preferably in the range of 1 to 300 ppm, more preferably 3 to 200 ppm, and still more preferably 5 to 100 ppm with respect to the amount of polyester to be melt-extruded. If the content of the phosphorus compound is too large, it may cause gelation or foreign matter. If the content is too small, the activity of the titanium compound cannot be lowered sufficiently, and the yellowish It may be a film.

  The polyester film of the present invention may contain an ultraviolet absorber in order to improve the weather resistance of the film and to prevent deterioration of the liquid crystal of a liquid crystal display used for a touch panel or the like. The ultraviolet absorber is not particularly limited as long as it is a compound that absorbs ultraviolet rays and can withstand the heat applied in the production process of the polyester film.

  Examples of the ultraviolet absorber include an organic ultraviolet absorber and an inorganic ultraviolet absorber, and 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.

  In the polyester layer of the film of the present invention, particles can be blended mainly for the purpose of imparting slipperiness and preventing scratches in each step. When the particles are blended, the kind of the particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness, and specific examples thereof include, for example, silica, calcium carbonate, magnesium carbonate, barium carbonate, sulfuric acid. Examples thereof include inorganic particles such as calcium, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, zirconium oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. 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. Of these, silica particles are preferred because they are particularly effective in a small amount.

  The average particle diameter of the particles is preferably 5 μm or less, more preferably 0.01 to 3 μm. By using the average particle size within the above range, an appropriate surface roughness is imparted to the film, and defects are less likely to occur when an active energy ray-curable resin layer is formed in a subsequent step.

  Furthermore, the particle content in the polyester layer is preferably less than 5% by weight, more preferably in the range of 0.0003 to 3% by weight. When there are no particles or when there are few particles, the transparency of the film becomes high and a good film is obtained, but care must be taken because slipperiness may be insufficient before the formation of the coating layer. Moreover, when there is too much particle | grain content, even if an active energy ray curable resin layer is formed, haze will not fully fall, and transparency of a film may be inadequate.

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 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 for producing the polyester constituting each layer, but it is preferably added after completion of esterification or transesterification.

  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 polyester film in the present invention is not particularly limited as long as it can be formed as a film, but it is preferably 10 to 350 μm, more preferably 20 to 300 μm.

  As a film forming method of the film of the present invention, a generally known film forming method can be adopted, and there is no particular limitation. For example, when producing a biaxially stretched polyester film, the polyester raw material described above is first melt-extruded from a die using an extruder, and the molten sheet is cooled and solidified with a cooling roll to obtain an unstretched sheet. In this case, in order to improve the flatness of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and an electrostatic application adhesion method or a liquid application adhesion method is preferably employed. Next, the obtained 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. Next, the film is stretched in the direction perpendicular to the first-stage stretching direction at usually 70 to 170 ° C. and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Subsequently, a method of obtaining a biaxially oriented film by performing heat treatment at a temperature of 180 to 270 ° C. under tension or under relaxation within 30% can be mentioned. 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.

  In the present invention, the simultaneous biaxial stretching method can be adopted for the production of the polyester film constituting the laminated polyester film. The simultaneous biaxial stretching method is a method in which the above-mentioned unstretched sheet is usually stretched and oriented in the machine direction and the width direction at a temperature controlled normally at 70 to 120 ° C., preferably 80 to 110 ° C. Is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in terms of area magnification. Subsequently, heat treatment is performed at a temperature of 170 to 270 ° C. under tension or relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

  Next, formation of the coating layer which comprises the laminated polyester film in this invention is demonstrated. Regarding the coating layer, it may be provided by in-line coating which treats the film surface during the process of forming a polyester film, or offline coating which is applied outside the system on a once produced film may be adopted. More preferably, it is formed by in-line coating.

  In-line coating is a method of coating within the process of manufacturing a polyester film, and specifically, a method of coating at any stage from melt extrusion of a polyester to heat setting after stretching and winding up. Usually, it is coated on any of an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat setting, and a film after heat setting and before winding. Although not limited to the following, for example, in sequential biaxial stretching, a method of stretching in the transverse direction after coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) is particularly excellent. According to such a method, film formation and coating layer formation can be performed at the same time, so there is an advantage in manufacturing cost. In addition, in order to perform stretching after coating, the thickness of the coating layer can be changed by the stretching ratio. Compared to offline coating, thin film coating can be performed more easily. Further, by providing the coating layer on the film before stretching, the coating layer can be stretched together with the base film, whereby the coating layer can be firmly adhered to the base film. Furthermore, in the production of a biaxially stretched polyester film, the film can be restrained in the longitudinal and lateral directions by stretching while gripping the film end with a clip, etc. High temperature can be applied while maintaining the properties. Therefore, since the heat treatment performed after coating can be performed at a high temperature that cannot be achieved by other methods, the film forming property of the coating layer can be improved, and the coating layer and the base film can be more firmly adhered to each other. Furthermore, it can be set as a firm coating layer, and performance, such as adhesiveness with the active energy ray-curable resin layer formed on a coating layer, and heat-and-moisture resistance, can be improved.

  In the present invention, it is an essential requirement to have a coating layer containing 10% by weight or more of particles having an average particle diameter of 0.10 to 1.0 μm on at least one surface of the polyester film.

  In applications where transparency is highly required, the present inventors are in a direction of decreasing transparency, but dare to contain a large amount of particles in the coating layer, improving the slipperiness of the film, in the post-processing step Prevents scratched defects and wrinkles. As a result of further investigation, according to the coating layer formation according to the present invention using particles of a specific size, the coating layer is made to contain particles by providing an active energy ray-curable resin layer on the coating layer. It was found that the haze generated in the above process can be reduced and a laminated polyester film having good transparency can be obtained. That is, the present inventors have found a method for producing a laminated polyester film having an active energy ray-curable resin layer having the characteristics of having few scratches and wrinkles while ensuring transparency.

  In addition to the above characteristics, improvements in various characteristics can be expected. By containing 10% by weight or more of particles having an average particle size of 0.10 to 1.0 μm, the contact area between the coating layer and the active energy ray-curable resin layer is increased, so that improvement in adhesion between both layers can be expected. . In addition, when a transparent active energy ray-curable resin layer is formed on a transparent substrate, the final product is also transparent, so it is difficult to determine whether it has been processed, but in the present invention, the haze is high and transparent before processing. However, since it becomes a transparent film with low haze after processing, there is an added value that it is easy to distinguish between processed and unprocessed. Furthermore, there is an effect of reducing interference unevenness due to external light reflection. Since irregularities due to particles are formed in the coating layer, when the active energy ray-curable resin layer is formed on the coating layer, the active energy ray-curable resin layer enters the concave portion of the coating layer, Since the boundary region with the active energy ray-curable resin layer is in the vicinity of the middle of the refractive index of both layers, the reflection of external light is weakened and interference unevenness is reduced.

  As the particles to be contained in the coating layer, various conventionally known particles can be used. For example, silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, Examples include inorganic particles such as zirconium oxide and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. Among them, inorganic particles are preferable in that hardness can be imparted, and silica particles are more preferable in consideration of stability in the state of the coating liquid.

  It is essential that the average particle size of the particles used in the coating layer is 0.10 to 1.0 μm, preferably 0.10 to 0.70 μm, more preferably 0.20 to 0.60 μm, still more preferably. It is in the range of 0.25 to 0.50 μm. By using it in these ranges, the slipperiness of the film becomes good and a high-quality film can be obtained. In addition, the advantage that the transparency after forming the active energy ray curable resin layer on the coating layer is improved, the advantage that the active energy ray curable resin layer can be easily distinguished from processing and unprocessed, and the application There is also an advantage that the falling of particles from the layer and the blocking of the film can be prevented. Moreover, the range of the boundary region in the thickness direction having a refractive index near the middle between the coating layer and the active energy ray curable resin layer becomes appropriate, and an effect can be expected to reduce interference unevenness due to reflection of external light.

  In the present invention, it is preferable to contain a polymer in the coating layer. The role of the polymer includes holding the above-described particles in the coating layer and improving the adhesion with the active energy ray-curable resin layer formed on the coating layer.

  A conventionally well-known polymer can be used as a polymer. Specific examples of the polymer include polyester resin, acrylic resin, urethane resin, polyvinyl (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, 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 the adhesion with the active energy ray-curable resin layer and improving the coating appearance. In view of compatibility with the polyester film of the base material, a polyester resin is more preferable, and from the viewpoint that adhesion with an active energy ray-curable resin layer such as a hard coat layer is further improved, an acrylic resin or a urethane resin is used. It is preferable to use together. Furthermore, in applications where it is necessary to reduce interference unevenness due to external light reflection, it is preferable to use a polyester resin that can easily increase the refractive index.

  The polyester resin includes, for example, those composed of the following polyvalent carboxylic acid and polyvalent hydroxy compound as main constituent components. That is, as the polyvalent carboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6 -Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutar Acid, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic acid monopotassium salt and ester-forming derivatives thereof can be used. As the polyvalent hydroxy compound, ethylene Recall, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol , Neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol Polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate, and the like can be used. One or more compounds may be appropriately selected from these compounds, and a polyester resin may be synthesized by a conventional polycondensation reaction.

  The acrylic resin is a polymer composed of a polymerizable monomer including acrylic and methacrylic monomers. These may be either homopolymers or copolymers, and copolymers with polymerizable monomers other than acrylic and methacrylic monomers. Moreover, the copolymer of these polymers and other polymers (for example, polyester, polyurethane, etc.) is also included. For example, a block copolymer or a graft copolymer. Alternatively, a polymer (possibly a mixture of polymers) obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion is also included. Similarly, a polymer obtained by polymerizing a polymerizable monomer in a polyurethane solution or a polyurethane dispersion (sometimes a mixture of polymers) is also included. Similarly, a polymer (in some cases, a polymer mixture) obtained by polymerizing a polymerizable monomer in another polymer solution or dispersion is also included. Moreover, in order to improve adhesiveness more, it is also possible to contain a hydroxyl group and an amino group.

  The polymerizable monomer is not particularly limited, but particularly representative compounds include, for example, various carboxyl groups such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid. Monomers, and salts thereof; such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutyl hydroxyl fumarate, monobutyl hydroxy itaconate Various hydroxyl group-containing monomers; various (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate; (Meth) acrylamide, Various nitrogen-containing compounds such as acetone acrylamide, N-methylol acrylamide or (meth) acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene, and various vinyls such as vinyl propionate Esters; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, etc .; phosphorus-containing vinyl monomers; various vinyl halides such as vinyl chloride and biridene chloride Various conjugated dienes such as butadiene.

  The urethane resin is a polymer compound having a urethane bond in the molecule. Usually, urethane resin is prepared by reaction of polyol and isocyanate. Examples of the polyol include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination.

  Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by a dealcoholization reaction. Examples of the polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentane. Diol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane Diol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylol heptane and the like can be mentioned. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate. Examples of polycarbonate polyols obtained from these reactions include poly (1,6-hexylene) carbonate, poly (3- And methyl-1,5-pentylene) carbonate.

  Polyester polyols include polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides. Product and polyhydric alcohol (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol 2-methyl-2-propyl-1 3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexane Diol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyl dialkanolamine, lactone diol, etc.).

  Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, and the like.

  Among the above polyols, polyester polyols and polycarbonate polyols are more preferably used in order to improve adhesion with the active energy ray-curable resin layer.

  Examples of the polyisocyanate compound used for obtaining the urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate, α, α, α ′, α ′. -Aliphatic diisocyanates having aromatic rings such as tetramethylxylylene diisocyanate, aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl Methanzi Cyanate, alicyclic diisocyanates such as isopropylidene dicyclohexyl diisocyanates. These may be used alone or in combination.

  A chain extender may be used when synthesizing the urethane resin, and the chain extender is not particularly limited as long as it has two or more active groups that react with an isocyanate group. Alternatively, a chain extender having two amino groups can be mainly used.

  Examples of the chain extender having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol and butanediol, aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene, and esters such as neopentyl glycol hydroxypivalate. And glycols such as glycols. Examples of the chain extender having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, and diphenylmethanediamine, ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3- Propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10- Aliphatic diamines such as decane diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylidenecyclohexyl-4,4′-diamine, 1,4-diaminocyclohexane, 1, 3-Bisaminomethylcyclohexa And alicyclic diamines such as

  The urethane resin in the present invention may use a solvent as a medium, but preferably uses water as a medium. In order to disperse or dissolve the urethane resin in water, there are a forced emulsification type using an emulsifier, a self-emulsification type in which a hydrophilic group is introduced into the urethane resin, and a water-soluble type. In particular, a self-emulsification type in which an ionic group is introduced into the structure of a urethane resin to form an ionomer is preferable because of excellent storage stability of the liquid and water resistance, transparency, and adhesion of the resulting coating layer.

Examples of the ionic group to be introduced include various groups such as a carboxyl group, sulfonic acid, phosphoric acid, phosphonic acid, quaternary ammonium salt, and the like, and a carboxyl group is preferable. As a method for introducing a carboxyl group into a urethane resin, various methods can be taken in each stage of the polymerization reaction. For example, there are a method of using a carboxyl group-containing resin as a copolymer component during prepolymer synthesis, and a method of using a component having a carboxyl group as one component such as polyol, polyisocyanate, and chain extender. In particular, a method in which a desired amount of carboxyl groups is introduced using a carboxyl group-containing diol depending on the amount of this component charged is preferred.
For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis- (2-hydroxyethyl) propionic acid, bis- (2-hydroxyethyl) butanoic acid and the like are copolymerized with a diol used for polymerization of a urethane resin. Can do. The carboxyl group is preferably in the form of a salt neutralized with ammonia, amine, alkali metal, inorganic alkali or the like. Particularly preferred are ammonia, trimethylamine and triethylamine. In such a polyurethane resin, a carboxyl group from which the neutralizing agent has been removed in the drying step after coating can be used as a crosslinking reaction point by another crosslinking agent. Thereby, it is possible to further improve the durability, solvent resistance, water resistance, blocking resistance, and the like of the obtained coating layer, as well as excellent stability in a liquid state before coating.

  Moreover, in order to improve the intensity | strength of an application layer, it is preferable to use a crosslinking agent together. Conventionally known materials can be used as the crosslinking agent, and examples thereof include oxazoline compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, melamine compounds, silane coupling compounds, hydrazide compounds, aziridine compounds, and the like. Among these, from the viewpoint of adhesion, an oxazoline compound, an epoxy compound, an isocyanate compound, and a carbodiimide compound are preferable. Moreover, in order to improve the adhesiveness with the active energy ray-curable resin layer, it is more preferable to use two or more kinds of crosslinking agents in combination. In particular, it has been found that the adhesion is remarkably improved when used in combination of an oxazoline compound and an epoxy compound, an oxazoline compound and an isocyanate compound, an oxazoline compound and a carbodiimide compound, or an isocyanate compound and a carbodiimide compound. In addition, in terms of increasing the strength of the coating layer, it has also been found that it is more preferable to use a melamine compound in combination, especially when the average particle size exceeds 0.2 μm and the particle content exceeds 10% by weight. Proved to be very effective.

  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 content of the oxazoline group contained in the oxazoline compound is usually 0.5 to 10 mmol / g, preferably 1 to 9 mmol / g, more preferably 3 to 8 mmol / g, and further preferably 4 to 6 mmol in terms of the amount of the oxazoline group. / G. Use within the above range is preferable because adhesion to the active energy ray-curable resin layer is improved.

  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 dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate and acetylacetone, mercaptan compounds such as butyl mercaptan and dodecyl mercaptan, lactam compounds such as ε-caprolactam and δ-valerolactam , Amine compounds such as diphenylaniline, aniline, ethyleneimine, acetanilide, acid amide compounds of acetic acid amide, formaldehyde, acetoald Examples include oxime compounds such as oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime, and these may be used alone or in combination of two or more. Among these, an active methylene compound is preferable from the viewpoint that adhesion to the active energy ray-curable resin layer is easily improved.

  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.

  The carbodiimide-based compound is a compound having a carbodiimide structure, and is used for improving the adhesion with the active energy ray-curable resin layer that can be formed on the coating layer and for improving the moisture and heat resistance of the coating layer. Is. The carbodiimide compound is a compound having one or more carbodiimide or carbodiimide derivative structures in the molecule, but a polycarbodiimide compound having two or more in the molecule is more preferable for better adhesion and the like.

  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.

  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.

  The content of the carbodiimide group contained in the carbodiimide-based compound is a carbodiimide equivalent (weight of the carbodiimide compound to give 1 mol of carbodiimide group [g]) and is usually 100 to 1000, preferably 250 to 800, more preferably 300. It is -700, More preferably, it is the range of 350-650. Use within the above range is preferable because adhesion to the active energy ray-curable resin layer is improved.

  The melamine compound is a compound having a melamine skeleton in the compound. For example, an alkylolized 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.

  These cross-linking agents are used in a design that improves the performance of the coating layer by reacting in the drying process or film forming process. It can be inferred that unreacted products of these crosslinking agents, compounds after the reaction, or mixtures thereof exist in the finished coating layer.

  In addition, in the present invention, when the active energy ray-curable resin layer such as a hard coat layer is formed on the coating layer and used for an application in which interference unevenness due to reflection of external light needs to be reduced, the coating layer is refracted. It is preferable to adjust the rate. In order to reduce the interference unevenness, the refractive index of the coating layer (1.55 to 1.65), the refractive index of the polyester film of the base material (1.60 to 1.70) and the refractive index of the active energy ray curable resin layer are used. It is preferable to design near the geometric mean of (1.45-1.65). A biaxially stretched polyester film that has high mechanical strength and is suitably used for various applications usually has a high refractive index. Therefore, the geometrical average of the refractive index of the polyester film and the refractive index of the active energy ray-curable resin layer formed on the coating layer is also high, and it is ideal that the coating layer has a high refractive index to reduce interference unevenness. It becomes.

  In order to increase the refractive index of the coating layer, it can be solved by using a material having a high refractive index for forming the coating layer. As a material having a high refractive index, a conventionally known material can be used. For example, an aromatic-containing compound such as a benzene structure, a bisphenol A structure, a melamine structure, a fluorene structure, or a high refractive index among aromatics. Examples thereof include condensed polycyclic aromatic compounds such as naphthalene structures considered as materials, metal-containing compounds such as metal oxides, compounds containing sulfur elements, and compounds containing halogen elements.

  Among these high refractive index materials, aromatics that can contain a large amount of various compounds such as polyester resins from the viewpoint of maintaining adhesion to an active energy ray-curable resin layer such as a hard coat layer. A compound is preferable, and when the refractive index is increased more effectively, a condensed polycyclic aromatic compound is more preferable. From the viewpoint of increasing the refractive index while increasing the strength of the coating layer, a melamine compound is also preferably used. Furthermore, it is possible to use a metal-containing compound such as a metal oxide in order to increase the refractive index more effectively than the aromatic compound.

  Considering the applicability on the polyester film and the adhesion to the active energy ray-curable resin layer, the aromatic compound is preferably a polyester resin, an acrylic resin or a urethane resin. In particular, it is more preferable from the viewpoint that more aromatic compounds can be introduced into the polyester resin, thereby increasing the refractive index.

  Among the aromatic compounds, the condensed polycyclic aromatic compound having a higher refractive index is, for example, naphthalene, anthracene, phenanthrene, naphthacene, benzo [a] anthracene, benzo [a] phenanthrene, pyrene, benzo [c] phenanthrene. And compounds having a structure such as perylene.

  As a method of incorporating the condensed polycyclic aromatic into the polyester resin, for example, two or more hydroxyl groups are introduced into the condensed polycyclic aromatic as a substituent to form a diol component or a polyvalent hydroxyl component, or There is a method in which two or more acid groups are introduced to prepare a dicarboxylic acid component or a polyvalent carboxylic acid component.

  In the laminated polyester film manufacturing process, the condensed polycyclic aromatic used for forming the coating layer is preferably a compound having a naphthalene structure in that it is difficult to be colored. In addition, a resin in which a naphthalene skeleton is incorporated as a polyester constituent is preferably used in terms of good adhesion to the active energy ray-curable resin layer formed on the coating layer and transparency. Representative examples of the naphthalene skeleton include 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and the like.

  In addition to the hydroxyl group and the carboxylic acid group, the condensed polycyclic aromatic has a refractive index of a refractive index by introducing a substituent containing a sulfur element, an aromatic substituent such as a phenyl group, a halogen element group, and the like. Improvements can be expected, and substituents such as alkyl groups, ester groups, amide groups, sulfonic acid groups, carboxylic acid groups, and hydroxyl groups may be introduced from the viewpoint of coating properties and adhesion.

  Further, as a metal-containing compound that can be expected as a material capable of effectively increasing the refractive index of the coating layer, a metal oxide having a high refractive index is preferably used, and a refractive index of 1.7 or more is used. Is preferred. Specific examples include, for example, zirconium oxide, titanium oxide, zinc oxide, tin oxide, antimony oxide, yttrium oxide, indium oxide, cerium oxide, ATO (antimony tin oxide), ITO (indium tin oxide), and the like. A metal oxide is mentioned. These may be used alone or in combination of two or more. Among these, zirconium oxide and titanium oxide are more preferably used. In particular, zirconium oxide is more preferably used from the viewpoint of weather resistance.

  The metal oxide is preferably used in the state of particles because there is a concern that the adhesiveness may be lowered depending on the use form, and the average particle diameter is preferably 100 nm or less, more preferably from the viewpoint of coating appearance and the like. Is in the range of 50 nm or less, more preferably 25 nm or less.

  In addition, as long as it does not impair the gist of the present invention, an antifoaming agent, a coating property improving agent, a thickening agent, an organic lubricant, an antistatic agent, an ultraviolet absorber, and an antioxidant are necessary for forming a coating layer. Agents, foaming agents, dyes, pigments and the like can be used in combination.

  As a ratio in the coating layer constituting the laminated polyester film in the present invention, the particles must be 10% by weight or more, preferably 12 to 60% by weight, more preferably 20 to 50% by weight, particularly preferably. It is in the range of 25 to 40% by weight. By using in the above range, the slipperiness of the film becomes sufficient, defects in the post-processing step can be reduced, and effective haze adjustment is possible, and the active energy ray-curable resin layer is not processed or not. It becomes easy to distinguish between processes. Further, the range of the boundary region in the surface direction having a refractive index near the middle between the coating layer and the active energy ray curable resin layer becomes appropriate, and an effect can be expected to reduce interference unevenness due to reflection of external light.

  As a ratio in the coating layer constituting the laminated polyester film in the present invention, the polymer is preferably 10 to 85% by weight, more preferably 15 to 75% by weight, still more preferably 25 to 65% by weight, particularly preferably 25 to 25%. It is in the range of 60% by weight. By using it in the above range, it is effective for good adhesion and prevention of falling off of particles.

  As a ratio in the coating layer constituting the laminated polyester film in the present invention, the component derived from the crosslinking agent is preferably less than 80% by weight, more preferably in the range of 5 to 65% by weight, further preferably 10 to 50% by weight, Especially preferably, it is the range of 10 to 40 weight%. By using in the said range, it becomes a favorable application | coating external appearance and a firm coating layer, and can form a high quality active energy ray curable resin layer. In particular, when it is desired to strengthen the coating layer, it is preferable to use a melamine compound in combination, and a preferable range thereof is 3 to 30% by weight, and more preferably 5 to 20% by weight.

  When used in applications where it is desired to reduce the occurrence of interference unevenness, it is preferable to use a compound having a condensed polycyclic aromatic in the coating layer in order to increase the refractive index of the coating layer. The proportion of the formula aromatic is preferably in the range of 5 to 80% by weight, more preferably in the range of 10 to 60% by weight. Moreover, as a ratio in the coating layer, the content of the compound having a condensed polycyclic aromatic is preferably in the range of 10 to 85% by weight, more preferably 20 to 50% by weight, as one component of the polymer described above. It is a range. By using within these ranges, the refractive index of the coating layer can be easily adjusted, and interference unevenness due to reflection of external light after forming the active energy ray-curable resin layer can be easily reduced. The ratio of the condensed polycyclic aromatic can be determined by, for example, dissolving and extracting the coating layer with an appropriate solvent or warm water, separating by chromatography, analyzing the structure by NMR or IR, and further pyrolyzing GC-MS (gas It can be determined by analyzing by chromatography mass spectrometry) or optical analysis.

  When used in applications where it is desirable to reduce the occurrence of interference unevenness, the amount of the above-mentioned polymer or cross-linking agent can be reduced and a metal oxide can be used in combination. The ratio of the metal oxide in the coating layer is preferably 3 to It is in the range of 30% by weight, more preferably in the range of 5 to 20% by weight. By using within these ranges, the refractive index of the coating layer can be easily adjusted, and interference unevenness due to reflection of external light after forming the active energy ray-curable resin layer can be easily reduced.

  In the polyester film of the present invention, it is also possible to provide a coating layer on the side of the polyester film opposite to the surface having the coating layer described above. As a constituent component of the coating layer, the above-described polymers and cross-linking agents can be used. The same coating layer may be used on both surfaces, or different coating layers may be used. For example, when the same active energy ray-curable resin layer is formed on both sides, the same coating layer is preferable, and when a different functional layer is provided on the back side, the active energy ray-curable resin layer of the present invention is in close contact. If the properties of the coatings are different, different coating layers can be used depending on the application.

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

  Regarding the formation of the coating layer, the above-described series of compounds is used as a solution or solvent dispersion, and the coating solution adjusted with a solid content concentration of about 0.1 to 80% by weight as a guide is laminated on the polyester film. It is preferred to produce a polyester film. In particular, when the coating layer is provided by in-line coating, an aqueous solution or a water dispersion is more preferable, but a small amount of an organic solvent is added to the coating solution for the purpose of improving the dispersibility in water and improving the film forming property. You may contain. Moreover, only one type of organic solvent may be used, and two or more types may be used as appropriate.

  Regarding the laminated polyester film in the present invention, the thickness of the coating layer provided on the polyester film is usually in the range of 0.001 to 1 μm, preferably 0.01 to 0.5 μm, more preferably 0.03 to 0.2 μm. It is. By adjusting the film thickness within the range, good coating appearance and adhesiveness with the active energy ray-curable resin layer are improved. Moreover, when using for the use which wants to reduce generation | occurrence | production of the interference nonuniformity by external light reflection, the film thickness of a coating layer becomes like this. Preferably it is 0.05-0.20 micrometers, More preferably, it is the range of 0.07-0.15 micrometers. is there.

  The relationship between the average particle diameter of the particles and the film thickness of the coating layer is preferably in the range of 1.0 or more, more preferably in the range of 1.2 to 20, as the average particle diameter / film thickness of the coating layer. Preferably it is the range of 1.5-15, Most preferably, it is the range of 1.7-10. By using in the above range, the slipping property of the coating layer becomes good, and it is possible to contribute to prevention of the particles from falling off the coating layer.

  In the film of the present invention, as a method for forming the coating layer, for example, gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roll coating, squeeze Conventionally known coating methods such as coating, impregnation coating, kiss coating, spray coating, calendar coating, extrusion coating, etc. can be used.

  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 40 at 80 to 200 ° C. The heat treatment may be performed for 2 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 270 ° 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.

  In order to reduce defects such as scratches and wrinkles during processing of the active energy ray-curable resin layer, it is preferable that the coating layer has good slipperiness. The coefficient of static friction can be cited as an index of slipperiness. It is possible to adjust by the average particle diameter and content of the particles contained in the coating layer. The range of the coefficient of static friction is preferably 0.7 or less, more preferably 0.1 to 0.6, and still more preferably 0.2 to 0.5. By using in these ranges, the slipping property of the film becomes an optimum range for processing the active energy ray-curable resin layer, and it is possible to prevent the occurrence of defects such as scratches and wrinkles. Moreover, it is also possible to reduce the point-like defect which generate | occur | produces because the slipperiness when it makes it roll shape is bad. In addition, when forming the active energy ray-curable resin layer on both sides, if the friction coefficient of the coating layer is low and the slipperiness is good, after forming the active energy ray-curable resin layer on one side, the opposite side surface Film for forming an active energy ray curable resin layer (ie active energy ray curable resin layer / coating layer containing more than 10% by weight of particles having an average particle diameter of 0.10 to 1.0 μm) Film / when the active energy ray-curable resin layer is formed on the coating layer on the surface layer in a layer configuration of a coating layer containing particles having an average particle size of 0.10 to 1.0 μm more than 10% by weight) There is also an advantage that slipperiness is improved and various defects can be reduced.

  In order to make it easy to distinguish between processing and non-processing of the active energy ray-curable resin layer, it is preferable that the haze is reduced by forming the active energy ray-curable resin layer on the coating layer. The amount of haze reduction is not particularly limited, but is preferably 1.0% or more, more preferably 3.0% or more, still more preferably 5.0% or more, particularly preferably 7.0% or more, and most preferably 10%. % Or more. By setting the above range, it becomes easy to distinguish between processing and non-processing of the active energy ray-curable resin layer according to various places such as a conference room, a work room, an inspection room, and how to read the film.

  Although the haze of the polyester film which has a coating layer before forming the active energy ray curable resin layer of this invention is not specifically limited, Preferably it is 3.0% or more. When adjusting the haze with particles, the appearance of the film depends on the type and size of the particles used, and also on the state of the substrate. In order to make it easier to distinguish the raw distinction, it is more preferably more than 5.0%, still more preferably more than 10%, particularly preferably more than 15%.

  In the present invention, it is an essential requirement to have an active energy ray-curable resin layer on the coating layer. Examples of the active energy ray-curable resin layer include a hard coat layer, a light diffusion layer, an anti-sticking layer, a prism layer, and a microlens layer. Although not particularly limited, the haze of the active energy ray-curable resin layer alone is preferably 8.0% or less, more preferably 3.0% or less, still more preferably 1.0% or less, particularly preferably. Is in the range of 0.5% or less. The thickness of the active energy ray-curable resin layer is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 1 to 15 μm, and still more preferably 1 to 8 μm.

  As an example of the active energy ray-curable resin layer, for example, in the case of a hard coat layer, the material to be used is not particularly limited. For example, monofunctional (meth) acrylate, polyfunctional (meth) acrylate, tetraethoxysilane, etc. And a cured product such as a reactive silicon compound. Among these, from the viewpoint of achieving both productivity and hardness, a polymerization cured product of a composition containing an active energy ray-curable (meth) acrylate is particularly preferable.

  The composition containing the active energy ray-curable (meth) acrylate is not particularly limited. For example, a mixture of one or more known active energy ray-curable monofunctional (meth) acrylates, bifunctional (meth) acrylates, polyfunctional (meth) acrylates, and commercially available as an active energy ray-curable hard coat resin material In addition, those other than these may be used as long as the object of the present embodiment is not impaired.

  The active energy ray-curable monofunctional (meth) acrylate is not particularly limited. For example, methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) ) Acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, alkyl (meth) acrylate such as isobornyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, etc. Alkyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxypropyl (meth) acrylate, etc. Amino group-containing (meth) acrylates such as xylalkyl (meth) acrylate, benzyl (meth) acrylate, aromatic (meth) acrylate such as phenoxyethyl (meth) acrylate, diaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, Methoxyethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, ethylene oxide modified (meth) acrylate such as phenylphenol ethylene oxide modified (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, Examples include (meth) acrylic acid.

  The active energy ray-curable difunctional (meth) acrylate is not particularly limited, and for example, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, alkanediol di (meth) acrylate such as tricyclodecane dimethylol di (meth) acrylate, bisphenol A ethylene oxide modified di (meth) acrylate Bisphenol F ethylene oxide modified di (meth) acrylate and other bisphenol modified di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, urethane di (meth) acrylate And epoxy di (meth) acrylate.

  The active energy ray-curable polyfunctional (meth) acrylate is not particularly limited, and examples thereof include dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, and ditrimethylolpropane tetra (meth) acrylate. , Pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate, ε-caprolactone modified tris (acryloxyethyl) isocyanurate Acrylate, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urea Down prepolymers, urethane acrylates such as dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, and the like.

  In addition, the active energy ray-curable resin layer such as a hard coat layer may be preferably designed to be high in order to reduce interference unevenness because the polyester film serving as a base material has a high refractive index. One method for increasing the refractive index is to use a metal oxide. As the metal oxide, a conventionally known metal oxide can be used. For example, zirconium oxide, titanium oxide, tin oxide, acid value yttrium, antimony oxide, indium oxide, zinc oxide, antimontin oxide, indium tin oxide Etc. Among these, zirconium oxide is preferable in consideration of environmental aspects, weather resistance, and price.

  Other components contained in the composition containing the active energy ray-curable (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. In addition, when the film is dried after film formation in the wet coating method, an arbitrary amount of solvent can be added.

  As a method for forming an active energy ray-curable resin layer such as a hard coat layer, a general wet coat method such as a roll coat method or a die coat method is employed when an organic material is used. 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. In addition, the refractive index of the active energy ray-curable resin layer formed on the coating layer is generally 1.45 to 1.65, preferably 1.48 to 1.55.

  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 measurement method and evaluation method used in the present invention are as follows.

(1) Method for measuring the intrinsic viscosity of polyester 1 g of polyester from which other polymer components and pigments incompatible with polyester have been removed are precisely weighed, and 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio) is added. And dissolved at 30 ° C.

(2) Measuring method of average particle diameter The coating layer was observed using TEM (H-7650 manufactured by Hitachi High-Technologies Corporation, acceleration voltage 100V), and the average value of the particle diameters of 10 particles was defined as the average particle diameter. .

(3) Method for measuring film thickness of coating layer The surface of the coating layer was dyed with RuO ₄ and embedded in an epoxy resin. Thereafter, the section prepared by ultramicrotomy stained with RuO _4, a coating layer cross-section was measured by using a TEM (Hitachi High Technologies Corporation H-7650, accelerating voltage 100 V). The film thickness was measured at a location not including the particle portion.

(4) Measuring method of refractive index The refractive index of the active energy ray-curable resin layer side was measured using a refractometer (SL-NA-B manufactured by Atago Co., Ltd.).

(5) Method of measuring coefficient of friction A film is pasted on a smooth glass plate having a width of 10 mm and a length of 100 mm with the coating layer side as the upper surface, and a film cut out to a width of 18 mm and a length of 120 mm is coated on the coating layer side. As the bottom surface, press against the metal pins with a diameter of 8 mm so that the coated layer sides rub against each other, slide the metal pins in the longitudinal direction of the glass plate at a load of 30 g and 40 mm / min, measure the frictional force, and start to slide The coefficient of friction (static coefficient of friction) at each point was measured. The measurement was performed in an atmosphere of room temperature 23 ± 1 ° C. and humidity 50 ± 0.5% RH, and when the friction coefficient was high and the measured runout was large, the intermediate value of the runout was taken as the friction coefficient.

(6) Measuring method of haze It measured by JISK7136 using the haze meter HM-150 by Murakami Color Research Laboratory.

(7) Measuring method of haze reduction when forming active energy ray-curable resin layer on coating layer Active energy ray-curable resin layer (haze of the layer is 0.2%) only on one side of the film After the formation, the haze was measured by the method according to (6), and the difference from the haze before forming the layer was calculated.

(8) Discrimination evaluation method before and after active energy ray curable resin layer processing A difference between a 20 cm × 20 cm film before and after forming an active energy ray curable resin layer on one side was observed. As an observation method, an active energy ray-curable resin layer is not formed in each of two places on a white desk (discriminability 1) and a black desk (discrimination 2) assuming a conference room and an examination room. The film and the film in which the active energy ray-curable resin layer was formed were placed, and the difference between the two was observed when observed from a location 1 m away at an angle of 30 degrees. 5 points if the difference can be discriminated instantaneously, 4 points if it can be easily discriminated by observation for 3 seconds, 3 points if it can be discriminated if you look carefully, 2 points if it is difficult to discriminate, 1 point if it cannot be discriminated did. A higher score is preferred.

(9) Method for evaluating adhesion of active energy ray-curable resin layer 10 × 10 cross after 50 hours in an environment of 80 ° C. and 90% RH with respect to the film on which the active energy ray-curable resin layer is formed Cut and affix an 18 mm wide tape (Cello Tape (registered trademark) CT-18 manufactured by Nichiban Co., Ltd.) on it, observe the peeled surface after abrupt peeling at a 180 degree peel angle, and peel off If the area is less than 5%, ◎ if it is 5% or more and less than 10%, ◯ if it is 10% or more and less than 50%, and x if it is 50% or more.

(10) Evaluation method of interference unevenness The film on which the active energy ray-curable resin layer is formed is visually observed under a three-wavelength fluorescent lamp and the interference unevenness cannot be confirmed. ◯ indicates that a slight interference unevenness is confirmed, Δ indicates a thin but linear interference unevenness, and × indicates a clear interference unevenness is confirmed.

The polyester used in the examples and comparative examples was prepared as follows.
<Method for producing polyester (A)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, 30 ppm of ethyl acid phosphate with respect to the resulting polyester, and 100 ppm of magnesium acetate tetrahydrate with respect to the resulting polyester as the catalyst at 260 ° C. in a nitrogen atmosphere at 260 ° C. The reaction was allowed to proceed. Subsequently, 50 ppm of tetrabutyl titanate was added to the resulting polyester, the temperature was raised to 280 ° C. over 2 hours and 30 minutes, the pressure was reduced to 0.3 kPa in absolute pressure, and melt polycondensation was further carried out for 80 minutes. 0.63 polyester (A) was obtained.

<Method for producing polyester (B)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, and magnesium acetate tetrahydrate as a catalyst were subjected to an esterification reaction at 225 ° C. in a nitrogen atmosphere at 900 ppm with respect to the produced polyester. Subsequently, 3500 ppm of orthophosphoric acid was added to the produced polyester, and 70 ppm of germanium dioxide was added to the produced polyester. The temperature was raised to 280 ° C. over 2 hours and 30 minutes, and the pressure was reduced to an absolute pressure of 0.4 kPa. After 85 minutes of melt polycondensation, polyester (B) having an intrinsic viscosity of 0.64 was obtained.

<Method for producing polyester (C)>
In the production method of polyester (A), polyester (C) is obtained using the same method as the production method of polyester (A) except that 0.3 part by weight of silica particles having an average particle diameter of 2 μm is added before melt polymerization. It was.

Examples of compounds constituting the coating layer are as follows.
(Example compounds)
Particles: (IA) Silica particles with an average particle size of 0.15 μm Particles: (IB) Silica particles with an average particle size of 0.20 μm Particles: (IC) Silica particles with an average particle size of 0.30 μm Particles: (ID ) Silica particles with an average particle size of 0.45 μm

・ Polyester resin with condensed polycyclic aromatic: (IIA)
Water dispersion of polyester resin copolymerized with the following composition: Monomer composition: (acid component) 2,6-naphthalenedicarboxylic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / diethylene glycol = 92/8 // 80/20 (mol%)

・ Polyester resin: (IIB)
Water dispersion of polyester resin copolymerized with the following composition: Monomer composition: (acid component) terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / 1,4-butanediol / diethylene glycol = 56/40/4 // 70/20/10 (mol%)

Acrylic resin: (IIC) Aqueous dispersion of acrylic resin polymerized with the following composition: ethyl acrylate / n-butyl acrylate / methyl methacrylate / N-methylol acrylamide / acrylic acid = 65/21/10/2/2 (% by weight) Emulsion polymer (emulsifier: anionic surfactant)

-Urethane resin: (IID)
Water of polyester urethane resin formed from isophorone diisocyanate unit: terephthalic acid unit: isophthalic acid unit: ethylene glycol unit: diethylene glycol unit: dimethylolpropanoic acid unit = 12: 19: 18: 21: 25: 5 (mol%) Dispersion.

・ Oxazoline compounds: (IIIA)
Acrylic polymer having an oxazoline group and a polyalkylene oxide chain Epocross (Oxazoline group amount = 4.5 mmol / g, manufactured by Nippon Shokubai Co., Ltd.)

Epoxy compound: (IIIB) polyglycerol polyglycidyl ether

・ Isocyanate compounds: (IIIC)
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 obtained by adding 58.9 parts of n-butanol, maintaining the reaction solution temperature at 80 ° C. for 2 hours, and then adding 0.86 part of 2-ethylhexyl acid phosphate.

・ Carbodiimide compounds: (IIID)
Polycarbodiimide compound Carbodilite (carbodiimide equivalent = 600, manufactured by Nisshinbo Co., Ltd.)

Melamine compound: (IIIE) hexamethoxymethylol melamine

Metal oxide: (IV) Zirconium oxide particles with an average particle size of 15 nm

Particles: (V) Silica particles with an average particle size of 0.07 μm

Example 1:
A mixed raw material in which polyesters (A), (B), and (C) were mixed in proportions of 91%, 3%, and 6%, respectively, was used as a raw material for the outermost layer (surface layer), and polyesters (A) and (B) were each 97 %, 3% of the mixed raw material is used as an intermediate layer raw material, each is supplied to two extruders, melted at 285 ° C., and then on a cooling roll set at 40 ° C. Coextruded with a layer structure of layers (surface layer / intermediate layer / surface layer = 1: 18: 1 discharge amount) and cooled and solidified to obtain an unstretched sheet. Next, the film was stretched 3.4 times in the longitudinal direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid 1 shown in Table 1 below was applied to both sides of the longitudinally stretched film in the thickness of the coating layer (dried). (After) was applied to 0.10 μm, led to a tenter, stretched 4.0 times at 120 ° C. in the transverse direction, heat treated at 225 ° C., relaxed 2% in the transverse direction, and 125 μm thick A polyester film was obtained.

  As an active energy ray-curable resin layer on the obtained polyester film coating layer, 77 parts by weight of dipentaerythritol hexaacrylate, 18 parts by weight of 2-hydroxy-3-phenoxypropyl acrylate, 5 parts by weight of zirconium oxide, photopolymerization start Hard coat coated with 5 parts by weight of an agent (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) and 200 parts by weight of methyl ethyl ketone so that the dry film thickness is 2 μm and cured by irradiating with ultraviolet rays. A film having a layer (having a haze of 0.2% and a refractive index of 1.51) formed on one side was obtained. Next, a film in which a hard coat layer was similarly formed on the coating layer on the back side was obtained.

  When the obtained hard coat film was evaluated, it was a coating layer with a low friction coefficient and good slipperiness, so there were no scratches or wrinkle defects, and processed / unprocessed discrimination, adhesion and interference unevenness were good. there were. The properties of this film are shown in Table 2 below.

Examples 2-18:
In Example 1, it manufactured similarly to Example 1 except having changed the coating agent composition into the coating agent composition shown in Table 1, and obtained the polyester film. As shown in Table 2, the finished polyester film was a coating layer having a low friction coefficient and good slipperiness, so there were no scratches or wrinkle defects, and it was a film with good discrimination between processed and unprocessed.

Example 19:
A mixed raw material in which polyesters (A) and (B) are mixed at a ratio of 97% and 3%, respectively, is used as a raw material for the outermost layer (surface layer), and polyesters (A) and (B) are respectively at a ratio of 97% and 3%. Each of the mixed raw materials is fed to two extruders as a raw material for the intermediate layer, melted at 285 ° C., and then two types and three layers (surface layer / intermediate layer / A non-stretched sheet was obtained by coextrusion and cooling and solidification in a layer configuration of (surface layer = 1: 18: 1 discharge amount). Next, the film was stretched 3.4 times in the longitudinal direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating solution 10 shown in Table 1 below was applied to both sides of this longitudinally stretched film with the film thickness (dried) (After) was applied to 0.10 μm, led to a tenter, stretched 4.0 times at 120 ° C. in the transverse direction, heat treated at 225 ° C., relaxed 2% in the transverse direction, and 125 μm thick A polyester film was obtained. An active energy ray-curable resin layer was formed on both sides in the same manner as in Example 1 on the obtained polyester film coating layer.

  When the obtained hard coat film was evaluated, it was a coating layer with a low friction coefficient and good slipperiness, so there were no scratches or wrinkle defects, and processed / unprocessed discrimination, adhesion and interference unevenness were good. there were. The properties of this film are shown in Table 2 below.

Comparative Example 1:
In Example 1, it manufactured similarly to Example 1 except having not provided the application layer, and obtained the polyester film. When the finished polyester film was evaluated, as shown in Table 2 below, the coefficient of friction was high, the slipping property of the coating layer was poor, and the discriminability and adhesion of processed / unprocessed were also poor.

Comparative Examples 2-4:
In Example 1, it manufactured similarly to Example 1 except having changed the coating agent composition into the coating agent composition shown in Table 1, and obtained the polyester film. When the finished polyester film was evaluated, as shown in Table 2 below, there were cases where the discrimination between processed and unprocessed was poor, the friction coefficient was high, and the slipperiness of the coating layer was not sufficient.

  The film of the present invention can be suitably used for applications requiring an active energy ray-curable resin layer such as a high-quality hard coat layer with few defects, such as a transparent electrode such as a touch panel and a molding film.

That is, the gist of the present invention is to have a coating layer containing 10% by weight or more of particles having an average particle diameter of 0.10 to 1.0 μm on at least one surface of the polyester film . A laminated polyester film characterized in that the relationship with the film thickness is in the range of 1.2 to 20 as the average particle diameter / film thickness of the coating layer, and the active energy ray-curable resin layer is provided on the coating layer. Exist.

Claims (1)

It has a coating layer containing 10% by weight or more of particles having an average particle diameter of 0.10 to 1.0 μm on at least one surface of the polyester film, and has an active energy ray-curable resin layer on the coating layer. A laminated polyester film.