JP2017173792A - Multilayer polyester film and method for manufacturing the manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer polyester film which has a layer containing a quantum dot with an excellent color reproductivity and has a coating layer with an excellent adhesion with the layer containing a quantum dot and which can be preferably used for various different types of displays such as a display backlight unit and members of a liquid crystal display.SOLUTION: The present invention relates to a multilayer polyester film having a coating layer and a quantum-dot containing layer on at least one surface of a polyester film base material, and also relates to a method for manufacturing the multilayer polyester film on at least one surface of the polyester film base material. According to the method, a coating solution is applied and is extended so that the coating layer is formed, and the quantum-dot containing layer is deposited on the coating layer.SELECTED DRAWING: None

Description

  The present invention relates to a laminated film that can be suitably used as a backlight unit of a display or a liquid crystal display device member, and is excellent in adhesion to a quantum dot-containing layer having excellent color reproducibility and a layer containing quantum dots. The present invention relates to a laminated polyester film having an excellent coating layer.

  In optical applications, polyester films are widely used mainly for various display applications such as backlight units and members of liquid crystal display devices because they are excellent in transparency and optical characteristics.

  In recent years, there has been a demand for a member that increases energy efficiency from the viewpoint of vivid color reproduction that is closer to reality and energy saving. Quantum dots are attracting attention as a method for achieving these required performances.

  Quantum dots are nanoscale semiconductor fine particles that can absorb and emit light from the LED and perform wavelength conversion. From this wavelength conversion characteristic, application to a display device has been studied (Patent Document 1, Patent Document 2).

  Since the wavelength of the converted light is determined by the size of the quantum dot, by controlling the size and composition of the material, energy can be concentrated in a narrow wavelength region of the three primary colors of red, green, and blue, and pass through the color filter. In this case, the color can be made clearer. In addition, since it concentrates in a narrow wavelength region, a color filter having higher transparency than that of a conventional LED can be used, so that the output of the backlight can be suppressed and the energy efficiency can be increased. .

  When quantum dots are used as a backlight unit member or a member of a liquid crystal display device, it is necessary to form a quantum dot-containing layer on the substrate. Although the method of providing a quantum dot directly on a base material, and the method of disperse | distributing and coating in ultraviolet curing type resin are illustrated (patent document 3, patent document 4), quantum dot itself and a base material Adhesion and adhesion between the UV curable resin and the substrate were insufficient.

JP 2013-048094 A Japanese Patent Laying-Open No. 2015-222384 JP 2006-216560 A Japanese Patent Laid-Open No. 2015-018131

  The present invention has been made in view of the above circumstances, and the problem to be solved is a laminated polyester having a quantum dot-containing layer having excellent color reproducibility and a coating layer having excellent adhesion to a layer containing quantum dots. To provide a film.

  As a result of intensive studies on the above problems, the present inventors have found that the above problems can be solved by providing a coating layer containing a specific type of compound, and the present invention has been completed. .

  That is, the gist of the present invention is to provide a laminated polyester film having a coating layer and a quantum dot-containing layer on at least one side of a polyester film substrate, and a coating layer and a quantum on at least one side of the polyester film substrate. A method for producing a laminated polyester film having a dot-containing layer, which comprises applying a coating solution, stretching to form a coating layer, and laminating a quantum dot-containing layer on the coating layer. Exist in the manufacturing method.

  According to the present invention, it is possible to provide a laminated polyester film having a quantum dot-containing layer having excellent color reproducibility and a coating layer having excellent adhesion to a layer containing quantum dots, which is higher than the conventional one. Since it can be used as a display member that enables color reproducibility and energy saving, the industrial value of the present invention 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, a titanium compound, a germanium compound, an antimony 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 is increased. Furthermore, since a germanium compound is expensive, it is more preferable to use a titanium compound.

  The polyester film of the present invention may contain an ultraviolet absorber for improving the weather resistance of the film and preventing deterioration of the liquid crystal. 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.

  As the ultraviolet absorber, there are an organic ultraviolet absorber and an inorganic ultraviolet absorber, and an organic ultraviolet absorber is preferable from the viewpoint of transparency. 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. 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 phosphoric acid. Examples include inorganic particles such as magnesium, kaolin, aluminum 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.

  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.

  Moreover, the average particle diameter of the particle | grains to be used is 5 micrometers or less normally, Preferably it is the range of 0.01-3 micrometers. When the thickness exceeds 5 μm, the surface roughness of the film becomes too rough, and a problem may occur when various surface functional layers are formed in a subsequent process.

  Furthermore, the content of particles in the polyester layer is usually 5% by weight or less, preferably 0.0003 to 3% by weight. When there are no or few particles, the transparency of the film becomes high and the film becomes a good film, but the slipperiness may be insufficient. There are cases where improvement is required. Further, when the particle content exceeds 5% by weight, the transparency of the film may be insufficient.

  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 the polyester film of the present invention, conventionally known antioxidants, antistatic agents, thermal stabilizers, lubricants, dyes, pigments and the like are added to the polyester film in the present invention, if necessary, in addition to the above-described particles and ultraviolet absorbers. be able to.

  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 is usually in the range of 10 to 350 μm, preferably 25 to 250 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. That is, a method is preferred in which pellets obtained by drying the polyester raw material described above are extruded as a molten sheet from a die using an extruder and 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 and / or a liquid application adhesion method is 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. Next, the film is stretched in the direction perpendicular to the first stretching direction. In that case, the stretching temperature is usually 70 to 170 ° C., and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. is there. 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.

  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 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, 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 the 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 this method, film formation and coating layer formation can be performed at the same time. In order to perform stretching after coating, the thickness of the coating layer can be changed depending on the stretching ratio, and thin film coating can be performed more easily than an off-line coating film. 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 performances such as adhesion to various functional layers that can be formed on the coating layer and wet heat resistance can be improved.

  The coating layer in the present invention can improve adhesion with the quantum dot-containing layer, and can be suitably used as a member of a backlight unit or a member of a liquid crystal display device.

  In the coating layer in the film of the present invention, it is preferable to use a binder resin for the purpose of improving the adhesion with the quantum dot-containing layer. Specific examples of the binder resin include acrylic resin, polyurethane resin, polyester resin, polyvinyl (polyvinyl alcohol, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, etc.), polyalkylene glycol, polyalkylene imine, methyl cellulose, hydroxy cellulose, starch And the like. These may be used alone or in combination.

  Among these binder resins, it is preferable to use an acrylic resin or a polyurethane resin from the viewpoint of further improving the adhesion.

  The acrylic resin that can be used for forming the coating layer in the film of the present invention is a polymer composed of a polymerizable monomer including an acrylic or methacrylic monomer. 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. From the viewpoint of improving adhesion, an acrylic resin having a glass transition temperature of 50 ° C. or lower, more preferably 40 ° C. or lower is preferable. Moreover, from a viewpoint of deterioration of blocking, a preferable lower limit of the glass transition temperature is −30 ° C.

  The polyurethane resin that can be used for forming the coating layer in the film of the present invention is a polymer compound having a urethane bond in the molecule, and is usually prepared by the reaction of a polyol and an 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. From the viewpoint of improving adhesion, polycarbonate polyols or polyester polyols are preferable, and polycarbonate polyols are more preferable.

  Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by a dealcoholization reaction. Polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, trimethylolpropane, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, , 5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, , 10-decanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylol heptane and the like. 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.) and those having derivative units of lactone compounds such as polycaprolactone.

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

  Examples of the polyisocyanates constituting the polyurethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate, α, α, α ′, α′-tetra. Aliphatic diisocyanates having an aromatic ring such as methylxylylene diisocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, aliphatic diisocyanates such as trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4 -Cyclohexyl Isocyanate), dicyclohexylmethane diisocyanate, alicyclic diisocyanates such as isopropylidene dicyclohexyl diisocyanates. These may be used alone or in combination of two or more. These polyisocyanate compounds may be a dimer, a trimer represented by an isocyanuric ring, or a polymer higher than that. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates from the viewpoint of improving adhesion to the active energy ray-curable coating material and preventing yellowing due to ultraviolet rays.

  A chain extender may be used when synthesizing the polyurethane 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, butanediol and pentanediol, aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene, neopentyl glycol and neopentyl. Examples include glycols such as ester glycols such as glycol hydroxypivalate. 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, isoprobilitincyclohexyl-4,4′-diamine, 1,4-diaminocyclohexane, 1 , 3-Bisaminomethylcyclohexa And alicyclic diamines such as isophorone diamine.

The polyurethane resin that can be used for forming the coating layer in the film of the present invention may be one that uses a solvent as a medium, but preferably one that uses water as a medium. In order to disperse or dissolve the polyurethane 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 polyurethane resin, and a water-soluble type. In particular, a self-emulsification type in which an ionic group is introduced into a skeleton of a polyurethane 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, and quaternary ammonium salt, and a carboxyl group is preferred. As a method for introducing a carboxyl group into a polyurethane 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, etc. are copolymerized with a diol used for polymerization of polyurethane 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, the carboxyl group from which the neutralizing agent is removed in the drying step of the coating solution can be used as a crosslinking reaction point by another crosslinking agent. Thereby, it is possible to further improve the durability, water resistance, blocking resistance, and the like of the obtained coating layer as well as excellent stability in a liquid state before coating.

  The polyester resin that can be used for forming the coating layer in the film of the present invention includes, for example, the following polyvalent carboxylic acid and polyvalent hydroxy compound as main components.

  Examples of the polyvalent carboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalene. Dicarnonic 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. .

  Examples of the polyvalent hydroxy compound include ethylene glycol, 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, ethylene glycol modified bisphenol A, diethylene glycol modified bisphenol A, diethylene glycol, triethylene glycol, polyethylene Glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, dimethylo Or the like can be used potassium Rupuropion acid. One or more of these polyvalent carboxylic acids and polyvalent hydroxy compounds may be appropriately selected, and a polyester resin may be synthesized by a conventional polycondensation reaction.

  The polyvinyl alcohol that can be used for forming the coating layer in the film of the present invention is a compound having a polyvinyl alcohol moiety, for example, a modified compound partially acetalized or butyralized with respect to polyvinyl alcohol, Conventionally known polyvinyl alcohol can be used. The degree of polymerization of polyvinyl alcohol is not particularly limited, but is usually 100 or more, preferably in the range of 300 to 40,000. When the degree of polymerization is less than 100, the water resistance of the coating layer may decrease. The saponification degree of polyvinyl alcohol is not particularly limited, but is usually 70 mol% or more, preferably in the range of 70 to 99.9 mol%, more preferably 80 to 97 mol%, and particularly preferably 86 to 97 mol%. A saponified polyvinyl acetate of 95 mol% is practically used.

  In the coating layer in the film of the present invention, a crosslinking agent may be used in combination in order to improve the adhesion between the coating layer and the quantum dot-containing layer or to strengthen the coating film. As the crosslinking agent, it is preferable to use an oxazoline compound, an isocyanate compound, an epoxy compound, a melamine compound, or a carbodiimide compound. Among these, it is more preferable to use at least one of an oxazoline compound or an isocyanate compound from the viewpoint of improving adhesion.

  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 and vinylidene chloride; styrene, An α, β-unsaturated aromatic monomer such as α-methylstyrene can be used, and one or more of these monomers can be used. From the viewpoint of improving adhesion, the amount of the oxazoline group of the oxazoline compound is preferably 0.5 to 10 mmol / g, more preferably 1 to 9 mmol / g, still more preferably 3 to 8 mmol / g, and particularly preferably 4 to 6 mmol / g. The range of g.

  The isocyanate compound is a compound having an isocyanate derivative structure represented 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.

  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. From the viewpoint of improving adhesion, a polyether-based epoxy compound is preferable. Further, the amount of the epoxy group is preferably a polyepoxy compound having a polyfunctionality of 3 or more rather than a bifunctional.

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.

  A carbodiimide 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., a polycarbodiimide compound having two or more in the molecule Compounds are more preferred.

  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 800, more preferably 300 to The range is 700. By using it in the above range, the durability of the coating film is improved.

  Further, in order to improve the water solubility and water dispersibility of the polycarbodiimide compound as long as the effects of the present invention are not lost, a surfactant is added, a polyalkylene oxide, a quaternary ammonium salt of a dialkylamino alcohol, a hydroxy A hydrophilic monomer such as an alkyl sulfonate may be added and used.

  When such a crosslinking component is contained, a component for accelerating crosslinking, for example, a crosslinking catalyst can be used in combination.

  The crosslinking agent used for the coating layer in the film of the present invention is used in a design that improves the performance of the coating layer by reacting in the drying process or the 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 the coating layer in the film of the present invention, particles can be used in combination as a constituent component of the coating layer in order to improve slipperiness and blocking.

  When the particles are used in combination, the average particle size is preferably in the range of 1.0 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.2 μm or less from the viewpoint of the transparency of the film. Specific examples of the particles include silica, alumina, kaolin, calcium carbonate, and organic particles.

  Furthermore, as long as it does not impair the gist of the present invention, the coating layer may include an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an ultraviolet absorber, an antioxidant, a foaming agent, a dye, A pigment or the like may be contained. These additives may be used independently and may use 2 or more types together as needed.

  As a ratio in the coating layer in the film of the present invention, the lower limit of the content of the binder resin is usually 30% by weight or more, preferably 40% by weight or more, and more preferably 50% by weight or more. If content of binder resin is 30 weight% or more, favorable adhesiveness with a quantum dot content layer will be acquired.

  As a ratio in the coating layer in the film of the present invention, the upper limit of the binder resin content is usually 90% by weight or less, preferably 80% by weight or less, and more preferably 75% by weight or less. If the content of the binder resin is 90% by weight or less, good coating strength can be obtained.

  As a ratio in the coating layer in the film of the present invention, the lower limit of the content of the crosslinking agent is usually 10% by weight or more, preferably 20% by weight or more, and more preferably 25% by weight or more. If the content of the crosslinking agent is 10% by weight or more, good coating strength can be obtained.

  As a ratio in the coating layer in the film of the present invention, the upper limit of the content of the crosslinking agent is usually 70% by weight or less, preferably 60% by weight or less, and more preferably 50% by weight or less. If content of a crosslinking agent is 70 weight% or less, favorable adhesiveness with a quantum dot content layer will be acquired.

  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.

  The film thickness of the coating layer in the film of the present invention is usually 0.002 to 1.0 μm, preferably 0.005 to 0.5 μm, more preferably 0.01 to 0.2 μm, and particularly preferably 0.01 to 0. The range is 1 μm. When the film thickness is less than the above range, the adhesion may be insufficient. When the film thickness exceeds the above range, there is a concern that adverse effects such as deterioration of blocking and increase of haze may occur.

  In the film of the present invention, as a method for providing the coating layer, a conventionally known coating method such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating or the like can be used.

  In the film of 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 at 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.

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

  In the present invention, the quantum dot used in the quantum dot-containing layer provided on the coating layer refers to a semiconductor having a diameter of 1 nm to 10 nm having a quantum confinement effect.

  When the quantum dot absorbs light from the excitation source and reaches an energy excited state, the quantum dot emits energy corresponding to the energy band gap of the quantum dot. Therefore, by adjusting the size of the quantum dots or the composition of the substance, the energy band gap can be adjusted, and energy in various levels of wavelength bands can be obtained.

  Therefore, by using quantum dots, various colors including red, green, and blue can be obtained with a narrow spectrum. Accordingly, it is possible to create colors that emit light at respective wavelengths, and it is possible to generate and reproduce white or various colors by mixing red, green, and blue.

  The quantum dots used in the quantum dot-containing layer in the present invention may be in the form of particles or dispersed in a solvent. The quantum dots dispersed in the solvent can be obtained, for example, by a chemical synthesis method in a liquid phase, and the solvent used may be an aqueous solvent or an organic solvent solvent.

  Semiconductor particles used as quantum dots used in the quantum dot-containing layer in the present invention include CdSe, CdTe, CdS, ZnSe, ZnTe, ZnS, II-VI group compounds such as HgS, HgSe, HgTe, GaAs, GaP, Examples include III-V group compounds such as GaN, GaSb, InN, InAs, InP, and InSb.

  Further, the quantum dots used in the quantum dot-containing layer in the present invention may have a core-shell structure composed of semiconductor fine particles having different core portions and shell portions. By using a material having a high band gap for the shell portion, the emission intensity can be improved. Here, the core is made of II-VI group compounds such as CdSe, CdTe, CdS, ZnSe, ZnTe, ZnS, HgS, HgSe, and HgTe, and III- such as GaAs, GaP, GaN, GaSb, InN, InAs, InP, and InSb. The shell includes any one substance selected from the group consisting of a group V compound and the like, and the shell is also a group II-VI compound such as CdSe, CdTe, CdS, ZnSe, ZnTe, ZnS, HgS, HgSe, HgTe, GaAs, It includes any one material selected from the group consisting of III-V group compounds such as GaP, GaN, GaSb, InN, InAs, InP, and InSb.

  In the quantum dot used in the quantum dot-containing layer in the present invention, the surface of the quantum dot may be substituted with an organic ligand in order to improve dispersibility and stability. Organic ligands include pyridine, mercaptoalcohol, thiol, phosphine, phosphine oxide, and the like, and serve to stabilize unstable quantum dots after synthesis. Examples of commercially available quantum dots include various quantum dots manufactured by SIGMA-ALDRICH.

  The quantum dot-containing layer in the present invention may be provided with quantum dots directly on a substrate or a resin dispersion, but it is preferable to use a layer dispersed in a resin. As the resin that can be used for dispersing the quantum dots, conventionally known resins can be used. Examples thereof include those made of an active energy ray-curable resin, and (meth) acrylate resins are typical examples. As a constituent compound of the resin, generally, for example, it has a polyhydric alcohol component such as ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, bisphenol A structure, polyurethane structure, polyester structure, epoxy structure and the like ( A meth) acrylate resin is mentioned.

  When using a resin dispersion as a quantum dot content layer in the present invention, content of a quantum dot to a quantum dot content layer is usually 1-50% by weight, preferably 3-40% by weight. If it is less than 1%, the color development and the luminance may not be sufficient, and if it exceeds 50% by weight, the adhesion to the coating layer may be insufficient.

  The thickness of the quantum dot containing layer in this invention is 0.1 micrometer-100 micrometers normally, Preferably it is the range of 1 micrometer-50 micrometers. When the thickness is less than 0.1 μm, the number of quantum dots decreases, so that color development and luminance may not be sufficient, and when the thickness is greater than 100 μm, there is a concern that the quantum dot-containing layer is insufficiently cured.

  The polyester film substrate in the present invention has a coating layer on at least one surface, but even if a similar or other coating layer or functional layer is provided on the opposite surface of the film, it is naturally included in the concept of the present invention.

  Since quantum dots are concerned about deterioration of durability when exposed to water vapor, it is preferable to impart barrier properties to the polyester film in the present invention. As a method of imparting barrier properties, a method of providing a barrier layer on the surface of the polyester film opposite to the quantum dot-containing layer, or a method of providing a barrier layer on a polyester film substrate and providing a coating layer thereon And a method of providing a barrier layer on the coating layer, and a method of bonding a substrate having other barrier properties to a polyester film. Among these, a method of providing a barrier layer on the surface opposite to the quantum dot-containing layer of the polyester film substrate is preferable because the step of bonding the barrier film can be omitted, and the processing cost can be reduced and the substrate can be thinned. .

As a material for the barrier layer, the barrier property is at a desired level. In the present invention, the water vapor permeability measured according to the JIS-K7129 B method is usually 0.01 g under the measurement conditions of a temperature of 40 ° C. and a humidity of 90% RH. / M ² / day or less, preferably 0.005 g / m ² / day or less. When the amount exceeds 0.01 g / m ² / day, moisture gradually enters the quantum dot-containing layer and tends to be deteriorated.

  Examples of the material for the barrier layer that can be used in the present invention include silicon compounds such as polysilazane compounds, polycarbosilane compounds, polysilane compounds, polyorganosiloxane compounds, and tetraorganosilane compounds, silicon oxide, silicon oxynitride, aluminum oxide, Inorganic oxides such as aluminum oxynitride, magnesium oxide, zinc oxide, indium oxide and tin oxide, inorganic nitrides such as silicon nitride and aluminum nitride, inorganic oxynitrides such as silicon oxynitride, aluminum, magnesium, zinc and tin And the like. These may be used alone or in combination of two or more.

  The thickness of the barrier layer that can be used in the present invention is preferably 1 nm to 10 μm, more preferably 10 to 1000 nm, and still more preferably 20 to 500 nm. If the thickness of the barrier layer is less than 1 nm, the barrier effect may be insufficient. On the other hand, when it exceeds 10 μm, it is in a saturated state in terms of performance, and it is difficult to expect a barrier effect any more.

  In addition, the barrier layer that can be used in the present invention may have a single layer configuration or a plurality of layers composed of two or more layers.

  Regarding a method for forming a barrier layer that can be used in the present invention, a conventionally known method can be used depending on the material constituting the barrier layer, and can be appropriately selected according to the purpose. For example, a method in which the barrier layer material is formed on a polyester film by vapor deposition, sputtering, ion plating, thermal CVD, plasma CVD, or the like, or a solution in which the barrier layer material is dissolved in an organic solvent Is applied to a polyester film, and plasma ion implantation is performed on the obtained coating film. Examples of ions implanted by plasma ion implantation include rare gases such as argon, helium, neon, krypton, and xenon, ions such as fluorocarbon, hydrogen, nitrogen, oxygen, carbon dioxide, chlorine, fluorine, and sulfur; gold, Examples include ions of metals such as silver, copper, platinum, nickel, palladium, chromium, titanium, molybdenum, niobium, tantalum, tungsten, and aluminum.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example in the range which does not exceed the summary. The measurement method and evaluation method used in the present invention are as follows.

(1) Measurement of 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. It was dissolved and measured at 30 ° C.

(2) Measuring method of average particle diameter The coating layer was observed using TEM (H-7650 made by Hitachi, 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 the ultrathin section method was stained with RuO _4, and the cross section of the coating layer was measured using TEM (H-7650 manufactured by Hitachi, accelerating voltage 100 V).

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

(5) Evaluation method of adhesion between coating layer and quantum dot-containing layer Applying an active energy ray-curable resin containing quantum dots, having the coating composition shown below, to a thickness of 10 μm on the coating layer, and releasing After laminating with a mold film, the resin was cured by irradiating with ultraviolet rays from an ultraviolet irradiation device with a high-pressure mercury lamp 160W so that the integrated light amount was 1000 mJ / cm ² . Subsequently, the release film was peeled off to obtain a film in which a quantum dot-containing layer was formed. The obtained quantum dot-containing layer is scratched at 5 mm intervals with a cutter knife, and a 24 mm wide tape (Cello Tape (registered trademark) CT-24 manufactured by Nichiban Co., Ltd.) is applied, and suddenly at a peeling angle of 180 degrees. After peeling, the peeled surface was observed, and if the peeled area was 5% or less, A was 5% and 20% or less, B was 20% and 50% or less C, and 50% or more was D. .
Active energy ray curable resin composition:
Quantum dot 1: CdSe / ZnS (emission peak 530 nm) 2 parts by weight Quantum dot 2: CdSe / ZnS (emission peak 620 nm) 2 parts by weight Dipentaerythritol pentaacrylate 63 parts by weight KARAYAD R-128H 10 parts by weight Ethylene glycol modified bisphenol A Acrylate (ethylene glycol chain = 8) 20 parts by weight Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide 3 parts by weight

(6) Evaluation of water vapor barrier property Under conditions of a temperature of 40 ° C. and a humidity of 90% RH, a water vapor transmission rate measuring device (model name, “Permatran” (registered trademark) W3 manufactured by MOCON, USA) / 31) was used and measured based on the B method (infrared sensor method) described in JIS K7129 (2000 version). Two test pieces were cut out from one sample, each test piece was measured once, and the average value of the two measured values was taken as the value of the water vapor transmission rate of the sample.

<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.

The following was used as the coating composition.
(A1): Emulsion-polymerized acrylic resin of ethyl acrylate / n-butyl acrylate / methyl methacrylate / N-methylol acrylamide / acrylic acid = 65/21/10/2/2 (% by weight) (glass transition point 40 ° C., emulsifier: Anionic surfactant)
(U1): formed from polycarbonate polyol consisting of 1,6-hexanediol and diethyl carbonate having a number average molecular weight of 2000: methylenebis (4-cyclohexylisocyanate): dimethylolpropanoic acid = 45: 50: 5 (mol%) An aqueous dispersion of polycarbonate polyurethane resin.
(E1): (acid component) terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / 1,4-butanediol / diethylene glycol = 56/40/4 // 70/20 / An aqueous dispersion of a polyester resin polymerized with a composition consisting of 10 (mol%).

(C1): 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.)
(C2): 1000 parts of hexamethylene diisocyanate was stirred at 60 ° C., and 0.1 part of tetramethylammonium caprate 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.

(C3): Water-soluble hexamethoxymethylolated melamine (C4): Water-soluble polyglycerol polyglycidyl ether.
(C5): Carbodiimide compound carbodilite (carbodiimide equivalent: 430) (Nisshinbo Co., Ltd.)

Example 1:
A mixed raw material in which polyesters (A), (B), and (C) are mixed at a ratio of 89%, 5%, and 6%, respectively, is used as a raw material for the outermost layer (surface layer), and polyesters (A) and (B) are each 95 %, 5% mixed raw materials were used as intermediate layer raw materials, each was supplied to two extruders, melted at 285 ° C., and then on a cooling roll set at 40 ° C. Coextruded and cooled and solidified in a layer structure of layers (surface layer / intermediate layer / surface layer = 1: 8: 1 discharge amount) 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 difference in peripheral speed of the roll, and then the coating solution 1 shown in Table 1 below was applied to one side of the longitudinally stretched film, which was led to a tenter. Polyester with a thickness of 25 μm, stretched 4.0 times at 110 ° C. in the transverse direction, heat treated at 225 ° C., relaxed 2% in the transverse direction, and the coating layer thickness (after drying) is 0.03 μm. A film was obtained.

Subsequently, the following barrier layer was laminated | stacked on the polyester film surface opposite to the said coating layer. Specifically, it was carried out after confirming that the water pressure in the vacuum chamber before sputtering was 1 × 10 ⁻⁴ Pa. As sputtering conditions, Al—Si (composition ratio Al: Si = 5: 5, manufactured by High Purity Chemical) was used as a target, and DC power of 3 W / cm ² was applied. Moreover, Ar gas was flowed, it was made into the atmosphere of 0.4 Pa, and it formed into a film using DC magnetron sputtering method. At this time, the magnetic field strength was 600 gauss. The center roll temperature was set to 0 ° C., and the oxygen flow rate was controlled using a Speedflo manufactured by Gencoa so that the discharge voltage during sputtering was constant. At this time, the discharge voltage was set to 50% when the discharge voltage when only Ar gas was supplied was 100%, and when the discharge voltage was 50% when Ar gas and O2 gas were supplied at 50 sccm. . As described above, a 40 nm-thickness barrier layer was deposited.

Subsequently, an active energy ray-curable resin containing quantum dots was applied on the coating layer so as to have a thickness of 10 μm, laminated with a release film (MRF38 manufactured by Mitsubishi Plastics, Inc.), and then irradiated with a high-pressure mercury lamp 160W from an ultraviolet irradiation device. The resin was cured by irradiating with ultraviolet rays so that the integrated light amount was 1000 mJ / cm ² . Subsequently, the release film was peeled off to obtain a film in which a quantum dot-containing layer was formed.

  When the obtained polyester film was evaluated, the adhesion between the coating layer and the quantum dot-containing layer was good, and the water vapor transmission rate was 0.005 (g / m2 / day). The properties of this film are shown in Table 2 below.

Examples 2-31:
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. These characteristics 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 quantum dot content layer was applied to the obtained polyester film and adhesiveness was evaluated, it was inferior to an example. This characteristic is shown in Table 2 below.

  The film of the present invention can be suitably used as a backlight unit member or a liquid crystal display device member.

Claims (6)

A laminated polyester film comprising a coating layer and a quantum dot-containing layer on at least one surface of a polyester film substrate. The laminated polyester film according to claim 1, wherein the polyester film substrate has a coating layer, a quantum dot-containing layer, and a barrier layer. The laminated polyester film according to claim 2, wherein a coating layer and a quantum dot-containing layer are laminated on one side of the polyester film substrate from the side close to the substrate, and a barrier layer is laminated on the opposite surface. The laminated polyester film according to any one of claims 1 to 3, wherein the quantum dot-containing layer contains a resin. A method for producing a laminated polyester film having a coating layer and a quantum dot-containing layer on at least one surface of a polyester film substrate. After coating a coating solution, the coating film is stretched to form a quantum dot on the coating layer. A method for producing a laminated polyester film, comprising laminating a content layer. The laminated polyester film according to any one of claims 1 to 4, which is used for a backlight unit member or a liquid crystal display device member.