White laminated polyester film

Abstract

This invention provides a white laminated polyester film that exhibits excellent adhesion to water and superior bonding to UV inks. The white laminated polyester film has a coating layer on at least one side of a polyester resin layer. This coating layer is formed by curing a composition comprising a polycarbonate structure with a branched structure, an aminocarbamate resin, a crosslinking agent, and a polyester resin.

Description

White laminated polyester film The present invention relates to a white laminated polyester film. More specifically, the present invention relates to a white laminated polyester film that reduces blocking when water adheres, has excellent ink adhesion, and is suitable as an information recording material or a printing material. Biaxially stretched polyester films are used as base films in many fields such as magnetic recording materials, packaging materials, electrical insulating materials, photosensitive materials, drafting materials, and photographic materials because of their excellent properties such as mechanical properties, electrical properties, and dimensional stability. However, when other materials are coated and laminated on the polyester film in these applications, there is a disadvantage that the adhesion is poor depending on the materials used. Therefore, as one method of imparting adhesion to the surface of the polyester film, a method of coating various resins on the surface of the polyester film to provide a coating layer having easy adhesion performance is known. In various conventional polyester-based coated films with different types of ink adhesion, a method of providing a coating layer composed of a specific resin on the surface of the base polyester film is also common (for example, refer to Patent Document 1). Examples of the constituent resin of the aforementioned coating layer include a single type or a mixture of two or more types such as polyester-based resins, polyurethane-based resins, and acrylic-based resins, and a mixture of the aforementioned resins and specific cross-linking agents (such as melamine and isocyanate). However, in the related prior art, especially when transporting film rollers between indoor and outdoor areas in a factory, etc., such as during winter, dew condensation may adhere to the film rollers due to the temperature difference between the indoor temperature and the outside air temperature, causing the film surface or the coating layer of the film to adhere to each other and resulting in a blocking failure. This blocking is different from the blocking that occurs under pressure after being placed in air containing normal water vapor, and it occurs through liquid water. That is, it is difficult to balance ink adhesion and blocking resistance. In particular, it is extremely difficult to balance adhesion to ultraviolet curable ink (UV (Ultraviolet) ink) and blocking resistance. To avoid this situation, seasoning is effective, but it cannot be completely avoided, and the following problem arises: the processing speed becomes slow due to the addition of the seasoning step, resulting in deteriorated productivity. [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-229355. [Problems to be Solved by the Invention] The present invention is based on the problems of the related prior art. That is, an object of the present invention is to provide a white laminated polyester film having excellent blocking resistance when water adheres and excellent adhesion to UV ink. [Means for Solving the Problems] In the process of studying the causes of the above problems in order to solve the above problems, the present inventors found that: when a coating layer is provided on at least one surface of a polyester film substrate, and the aforementioned coating layer is formed by curing a composition containing a crosslinking agent, a polyester resin, and a urethane resin having a polycarbonate structure and a branched structure, the problems of the present invention can be solved, and thus the present invention has been completed. That is, the present invention is composed of the following constitution. 1. A white laminated polyester film having a coating layer on at least one surface of a polyester film substrate, wherein the aforementioned coating layer is formed by curing a composition containing a urethane resin having a polycarbonate structure and a branched structure, a crosslinking agent, and a polyester resin. 2. The white laminated polyester film according to the above item 1, wherein the aforementioned crosslinking agent is a compound having a blocked isocyanate group with a functionality of 3 or more. 3. The white laminated polyester film according to the above item 1 or 2, wherein the urethane resin having a polycarbonate structure and a branched structure is synthesized and polymerized from a polycarbonate polyol component and a polyisocyanate component, and the mass ratio of the polycarbonate polyol component to the polyisocyanate component (mass of polycarbonate polyol component / mass of polyisocyanate component) during the aforementioned synthesis and polymerization is 0.5 to 3. [Invention Effect] The white laminated polyester film of the present invention does not cause adhesion even when condensed water adheres, and has excellent adhesion to UV ink. In particular, it has excellent adhesion to UV ink during low-dose processing. [Polyester Film Substrate] In the present invention, the polyester resin constituting the polyester film substrate is, in addition to polyethylene terephthalate, polybutylene terephthalate, poly(ethylene 2,6-naphthalate), polypropylene terephthalate, etc., also a copolyester resin obtained by replacing a part of the glycol component or dicarboxylic acid component of the above-mentioned polyester resin with the following copolymer components. For example, as the copolymer components, glycol components such as diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, and polyalkylene glycol, or dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, 5-sodium isophthalic acid, and 2,6-naphthalenedicarboxylic acid can be mentioned. In the present invention, the polyester resin suitable for the polyester film substrate is mainly selected from polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and poly(ethylene 2,6-naphthalate). Among these polyester resins, polyethylene terephthalate is the best in terms of the balance between physical properties and cost. In addition, the polyester film substrate composed of these polyester resins is preferably a biaxially stretched polyester film, which can improve chemical resistance, heat resistance, mechanical strength, etc. The catalyst for polycondensation used in the production of the polyester resin is not particularly limited. Since antimony trioxide is a catalyst that is inexpensive and has excellent catalytic activity, it is preferred. In addition, it is also preferred to use a germanium compound or a titanium compound. As a more preferred polycondensation catalyst, examples include: a catalyst containing aluminum and / or its compound and a phenolic compound, a catalyst containing aluminum and / or its compound and a phosphorus compound, and a catalyst containing an aluminum salt of a phosphorus compound. In terms of practical properties such as strength and stiffness, the polyester film substrate in the present invention is particularly preferably a biaxially oriented film. The layer structure of the polyester film substrate can be a single-layer structure or a laminated structure. The following laminated structure is a preferred form: a laminated structure of A layer / B layer / A layer, and inorganic particles are contained in the A layer, and fine voids are contained in the B layer. By disposing a layer containing inorganic particles in the A layer as the surface layer, the lubricity (i.e., operability) or hiding property of the film can be improved. By making only the B layer as the inner layer contain fine voids, in addition to obtaining a better white appearance, the buffering property of the film can be exhibited and the strength of the film surface can also be ensured. Here, the method of forming the laminated structure is not particularly limited. From the viewpoints of stability during production and processing cost, it is preferably carried out by coextrusion. In addition, the polyester film substrate in the present invention can be a single-layer structure or a multi-layer structure. Preferably, a part or all of the layers of the polyester film substrate are opaque. The optical density showing the opacity of the white laminated polyester film is preferably 0.3 or more, more preferably 0.3 to 4.0, and particularly preferably 0.5 to 3.0. When printing is carried out on the surface of the coating layer of the white laminated polyester film, if the optical density is 0.3 or more, the printing effect becomes clear and is preferable. In addition, if the optical density is 4.0 or less, a more excellent printing effect can be expected and is preferable. The method for obtaining the optical density within the above range is not particularly limited, and can be achieved by making the polyester resin contain inorganic particles or a thermoplastic resin that is not compatible with the polyester resin. The content of these substances is not particularly limited. In the case of inorganic particles, it is preferably 5% by mass to 35% by mass, particularly preferably 8% by mass to 25% by mass, based on the polyester produced. On the other hand, in the case of containing an incompatible thermoplastic resin, it is preferably 5% by mass to 35% by mass, particularly preferably 8% by mass to 28% by mass, based on the polyester. In addition, when inorganic particles and a thermoplastic resin that is not compatible with the polyester resin are used in combination, in terms of film strength, stiffness, and film-forming stability, the total amount of the inorganic particles and the thermoplastic resin that is not compatible with the polyester resin is preferably 40% by mass or less based on the polyester film substrate. The inorganic particles used are not particularly limited, and inorganic particles with an average particle diameter of 0.1 μm to 4.0 μm are preferred, and inorganic particles with an average particle diameter of 0.3 μm to 1.5 μm are particularly preferred. Specifically, white pigments such as titanium oxide, barium sulfate, calcium carbonate, and zinc sulfide are preferred, and these can also be mixed. Furthermore, inorganic particles commonly contained in the film, such as silica, alumina, talc, kaolin, clay, calcium phosphate, mica, lithium montmorillonite, zirconia, tungsten oxide, lithium fluoride, calcium fluoride, calcium sulfate, etc., can also be used in combination. In addition, as the thermoplastic resin that is not compatible with the polyester resin, there is no particular limitation. For example, when mixed with polyethylene terephthalate resin, examples include: polystyrene resin, polyolefin resins such as polyethylene resin, polypropylene resin, and polymethylpentene resin, acrylic resin, phenoxy resin, polyphenylene ether resin, polycarbonate resin, etc. In addition, these thermoplastic resins can also be mixed and modified. Of course, they can also be used in combination with the above-mentioned inorganic particles. In addition, of course, various brightening agents can be added as needed. Regarding the method for measuring the average particle diameter of the particles, it is measured by the following method: observing the particles on the cross-section of the film using a scanning electron microscope, observing 50 particles, and taking the average value of these 50 particles as the average particle diameter. As long as the object of the present invention is satisfied, the shape of the particles is not particularly limited, and spherical particles or irregular non-spherical particles can be used. The particle diameter of the irregular particles can be calculated in the form of a circular equivalent diameter. The circular equivalent diameter is the value obtained by dividing the area of the observed particles by π, calculating the square root, and multiplying by 2 times. Furthermore, the white laminated polyester film of the present invention preferably has an apparent density of 0.3 g / cm 3 to 1.3 g / cm 3 and is a polyester film containing fine voids. In addition, in terms of having both buffering properties and surface peel strength, a white laminated polyester film with a void laminate number density of 0.20 pieces / μm or more, preferably 0.25 pieces / μm or more, and more preferably 0.30 pieces / μm or more is also preferred. As a result, the obtained white laminated polyester film has excellent printing clarity or processing characteristics during printing. Here, the void laminate number density (pieces / μm) is defined by the following formula: the number of voids in the film thickness direction (pieces) / film thickness (μm). In terms of the void expression efficiency, the upper limit of the void laminate number density is preferably 0.80 pieces / μm, and more preferably 0.55 pieces / μm. As a method for adjusting the density to the above range, in addition to adjusting the addition amount, type, viscosity, etc. of the incompatible thermoplastic resin, methods such as changing the screw shape of the extruder or installing a static mixer in the molten resin flow path can also be used, but it is not limited thereto. Regarding the white laminated polyester film containing these voids, light scattering occurs at the interface between the fine voids contained in the film and the polyester serving as the matrix, thereby further increasing the opacity and enabling a reduction in the addition of the aforementioned inorganic particles. Therefore, it is particularly useful. Furthermore, by containing fine voids, the matrix film itself can be made lighter, making the operation easier, and the economic effects such as a reduction in raw material costs or transportation costs also become greater. As a method for obtaining such a white laminated polyester film, known methods such as the following methods can be used: For a thermoplastic polyester resin serving as the matrix, a thermoplastic resin that is immiscible with the polyester resin as described above is kneaded, and a sheet in which the immiscible resin is dispersed in the form of fine particles in the polyester resin is stretched at least in the uniaxial direction, thereby generating voids around the fine particles of the immiscible resin. In addition, the thickness of the obtained white laminated polyester film is preferably 5 μm to 300 μm. In particular, the thickness of the white laminated polyester film having a void layer number density of 0.20 or more per μm is preferably 20 μm to 300 μm, more preferably 40 μm to 250 μm. The whiteness required for use in printing materials and the like can be represented by color values. In particular, the color L value is a scale representing brightness, and the higher the numerical value, the whiter. Furthermore, the higher the numerical value of the color b value, the stronger the yellow tone, and the lower the numerical value, the stronger the blue tone. That is, a high L value and a low b value indicate high whiteness and a strong white tone as visually observed, indicating good clarity during printing. [Coating layer] In order to improve the adhesion to UV ink and the adhesion resistance during water adhesion of the white laminated polyester film of the present invention, it is preferably laminated with a coating layer on at least one side. The coating layer is formed by curing a composition containing a urethane resin having a polycarbonate structure and a branched structure, a crosslinking agent, and a polyester resin. Regarding the aforementioned coating layer, it can be considered that the coating layer in the coating is a layer formed by crosslinking and curing a urethane resin or a polyester resin having a polycarbonate structure and a branched structure through a crosslinking agent. However, since it is difficult to describe the chemical structure itself after crosslinking, it is described as being formed by curing a composition containing a urethane resin having a polycarbonate structure and a branched structure, a crosslinking agent, and a polyester resin. The coating layer can be provided on both sides of the polyester film substrate, or can be provided only on one side of the polyester film substrate, and a resin coating layer of a different type can be provided on the other side. Hereinafter, each component of the coating layer will be described in detail. [Urethane resin having a polycarbonate structure and a branched structure] The urethane resin having a polycarbonate structure in the present invention preferably has at least a urethane bond portion and a branched structure derived from a polycarbonate polyol component and a polyisocyanate component, and further contains a chain extender as needed. The branched structure mentioned here refers to a structure preferably introduced by the following method: the number of terminal functional groups of any of the raw material components as described above constituting the molecular chain is 3 or more, whereby a molecular chain structure on the branch is formed after synthesis and polymerization. In the urethane resin having a polycarbonate structure and a branched structure in the present invention, due to this branched structure, the lower limit of the number of terminal functional groups in the molecular chain is preferably 3, more preferably 4. If it is 3 or more, it is preferable because the adhesion resistance during water adhesion can be improved. In the urethane resin having a polycarbonate structure in the present invention, due to this branched structure, the upper limit of the number of terminal functional groups in the molecular chain is preferably 6. If it is 6 or less, it is preferable because the resin can be stably dispersed in an aqueous solution. When synthesizing and polymerizing the urethane resin having a polycarbonate structure and a branched structure in the present invention, the mass ratio of the polycarbonate polyol component to the polyisocyanate component (mass of polycarbonate polyol component / mass of polyisocyanate component) preferably has a lower limit of 0.5, more preferably 0.6, particularly preferably 0.7, especially preferably 0.8, and most preferably 1.0. If it is 0.5 or more, it is preferable because the adhesion to UV ink can be improved. When synthesizing and polymerizing the urethane resin having a polycarbonate structure in the present invention, the upper limit of the mass ratio of the polycarbonate polyol component to the polyisocyanate component is preferably 3.0, more preferably 2.2, particularly preferably 2.0, especially preferably 1.7, and most preferably 1.5. If it is 3.0 or less, it is preferable because the adhesion resistance during water adhesion can be improved. In the polycarbonate polyol component used for synthesizing and polymerizing the urethane resin having a polycarbonate structure and a branched structure in the present invention, it is preferable to contain an aliphatic polycarbonate polyol having excellent heat resistance and hydrolysis resistance. Examples of the aliphatic polycarbonate polyol include aliphatic polycarbonate diols and aliphatic polycarbonate triols, and aliphatic polycarbonate diols can be preferably used. Examples of the aliphatic polycarbonate diol used for synthesizing and polymerizing the urethane resin having a polycarbonate structure in the present invention include, for example, aliphatic polycarbonate diols obtained by reacting one or more of glycols such as ethylene glycol, propylene glycol, 1,3 - propanediol, 1,4 - butanediol, 1,5 - pentanediol, 3 - methyl - 1,5 - pentanediol, 1,6 - hexanediol, 1,9 - nonanediol, 1,8 - nonanediol, neopentyl glycol, diethylene glycol, and dipropylene glycol with carbonate esters such as dimethyl carbonate, ethylene carbonate, and phosgene. The number average molecular weight of the polycarbonate polyol in the present invention is preferably from 1000 to 3000, more preferably from 1200 to 2900, and most preferably from 1500 to 2800. If it is 1000 or more, it is preferable because the ink adhesion can be improved. If it is 3000 or less, it is preferable because the adhesion resistance during water adhesion can be improved. Examples of the polyisocyanate used for the synthesis and polymerization of the urethane resin having a polycarbonate structure and a branched structure in the present invention include aromatic aliphatic diisocyanates such as xylylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 1,3-bis(isocyanatemethyl)cyclohexane Alicyclic diisocyanates, aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, or polyisocyanates obtained by previously adding a single or plural kinds of these compounds to trimethylolpropane or the like. When using the aforementioned aromatic aliphatic diisocyanates, alicyclic diisocyanates, or aliphatic diisocyanates, etc., there is no problem of yellowing, which is preferable. In addition, it will not become an overly hard coating film, can relieve the stress caused by the heat shrinkage of the polyester film substrate, and make the adhesion good, which is preferable. Examples of the chain extender include glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol; polyols such as glycerol, trimethylolpropane, and pentaerythritol; diamines such as ethylenediamine, hexamethylenediamine, and piperazine; amino alcohols such as monoethanolamine and diethanolamine; thiodiethylene glycols such as thiodiethylene glycol; or water. In order to form a branched structure in the urethane resin, for example, the following method can be preferably adopted: after reacting the polycarbonate polyol component, polyisocyanate, and chain extender at an appropriate temperature and time, a compound having 3 or more functional hydroxyl groups or isocyanate groups is added, and the reaction is further carried out. Specific examples of the compound having 3 or more functional hydroxyl groups include caprolactone triol, glycerol, trimethylolpropane, butanetriol, hexanetriol, 1,2,3-hexanetriol, 1,2,3-pentanetriol, 1,3,4-hexanetriol, 1,3,4-pentanetriol, 1,3,5-hexanetriol, 1,3,5-pentanetriol, polyether triol, etc. Examples of the aforementioned polyether triol include compounds obtained by the following method: using one or two or more of alcohols having 3 active hydrogens such as glycerol and trimethylolpropane, and diethylenetriamine as initiators, and adding one or two or more of monomers such as ethylene oxide, propylene oxide, butylene oxide, pentylene oxide, glycidyl ether, methyl glycidyl ether, tert-butyl glycidyl ether, and phenyl glycidyl ether for addition polymerization. As a specific example of a compound having three or more isocyanate groups, a polyisocyanate compound having at least three or more isocyanate (NCO) groups in one molecule may be used. In the present invention, examples of the isocyanate compound having three or more functional groups include biuret bodies, allophanate bodies, and adducts obtained by modifying isocyanate monomers such as aromatic diisocyanates, aliphatic diisocyanates, araliphatic diisocyanates, and alicyclic diisocyanates having two isocyanate groups. Examples of aromatic diisocyanates include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-toluidine diisocyanate, dimethoxybenzidine diisocyanate, and 4,4'-diphenyl ether diisocyanate. Examples of aliphatic diisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate. Examples of araliphatic diisocyanates include xylylene diisocyanate, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, and 1,3-tetramethylxylylene diisocyanate. Examples of alicyclic diisocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (alias: IPDI, isophorone diisocyanate), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,4-bis(isocyanatomethyl)cyclohexane. The so-called biuret body is a self-condensate having a biuret bond formed by self-condensation of an isocyanate monomer, and examples thereof include a biuret body of hexamethylene diisocyanate. The so-called allophanate body is a trimer of an isocyanate monomer, and examples thereof include a trimer of hexamethylene diisocyanate, a trimer of isophorone diisocyanate, and a trimer of toluene diisocyanate. The so-called adduct is a compound having three or more functional groups obtained by reacting the above isocyanate monomer with a compound having low molecular weight active hydrogen having three or more functional groups, and examples thereof include a compound obtained by reacting trimethylolpropane with hexamethylene diisocyanate, a compound obtained by reacting trimethylolpropane with toluene diisocyanate, a compound obtained by reacting trimethylolpropane with xylylene diisocyanate, and a compound obtained by reacting trimethylolpropane with isophorone diisocyanate. As a chain extender having a functionality of 3 or more, it corresponds to alcohols having a hydroxyl group with a functionality of 3 or more, such as trimethylolpropane and pentaerythritol, etc., as described in the above chain extender. In the present invention, the coating layer is preferably provided by an in-line coat method using an aqueous coating solution. Therefore, the urethane resin of the present invention preferably has water solubility or water dispersibility. Furthermore, the aforementioned "water solubility or water dispersibility" means being dispersed in water or an aqueous solution containing an organic solvent with a water solubility of less than 50% by mass. In order to impart water dispersibility to the urethane resin, a sulfonic acid (salt) group or a carboxylic acid (salt) group can be introduced (copolymerized) into the urethane molecular backbone. In order to maintain moisture resistance, it is preferable to introduce a weakly acidic carboxylic acid (salt) group. In addition, a nonionic group such as a polyoxyalkylene group can also be introduced. In order to introduce a carboxylic acid (salt) group into the urethane resin, for example, a polyol compound having a carboxylic acid group such as dimethylolpropionic acid and dimethylolbutyric acid as a polyol component can be introduced as a copolymerization component and neutralized with a salt-forming agent. Specific examples of the salt-forming agent include: ammonia; trialkylamines such as trimethylamine, triethylamine, triisopropylamine, tri-n-propylamine, and tri-n-butylamine; N-alkylmorpholines such as N-methylmorpholine and N-ethylmorpholine; N-dialkylalkanolamines such as N-dimethylethanolamine and N-diethylethanolamine. These can be used alone or two or more of them can be used in combination. When a polyol compound having a carboxylic acid (salt) group is used as a copolymerization component to impart water dispersibility, the molar composition of the polyol compound having a carboxylic acid (salt) group in the urethane resin is preferably 3 mol% to 60 mol%, more preferably 5 mol% to 40 mol%, when the total polyisocyanate component of the urethane resin is set to 100 mol%. When the aforementioned molar composition ratio is 3 mol% or more, water dispersibility can be obtained, which is preferable. In addition, when the aforementioned molar composition ratio is 60 mol% or less, water resistance can be maintained and wet heat resistance can be obtained, which is preferable. The urethane resin in the present invention can also have a blocked isocyanate structure at the terminal in order to improve rigidity. [Crosslinking agent] In the present invention, as the crosslinking agent contained in the composition for forming the coating layer, a blocked isocyanate is preferable, a blocked isocyanate having a functionality of 3 or more is more preferable, and a blocked isocyanate having a functionality of 4 or more is particularly preferable. Thereby, the adhesion resistance at the time of water adhesion can be improved. The lower limit of the NCO equivalent of the aforementioned blocked isocyanate is preferably 100, more preferably 120, particularly preferably 130, especially preferably 140, and most preferably 150. If the NCO equivalent is 100 or more, there is no concern of film cracking, which is preferable. The upper limit of the NCO equivalent is preferably 500, more preferably 400, particularly preferably 380, especially preferably 350, and most preferably 300. If the NCO equivalent is 500 or less, the adhesion resistance during water adhesion can be improved, which is preferable. The lower limit of the boiling point of the blocking agent of the aforementioned blocked isocyanate is preferably 150 °C, more preferably 160 °C, particularly preferably 180 °C, especially preferably 200 °C, and most preferably 210 °C. The higher the boiling point of the blocking agent, even under the influence of the drying step after coating the coating liquid or the additional heat during the film formation step when using the in-line coating method, the volatilization of the blocking agent can be suppressed, the generation of minute irregularities on the coating surface can be suppressed, and the transparency of the film can be improved. The upper limit of the boiling point of the blocking agent is not particularly limited, and in terms of productivity, it is considered that around 300 °C is the upper limit. Since the boiling point is related to the molecular weight, in order to increase the boiling point of the blocking agent, it is preferable to use a blocking agent with a large molecular weight. The molecular weight of the blocking agent is preferably 50 or more, more preferably 60 or more, and particularly preferably 80 or more. The upper limit of the dissociation temperature of the blocking agent is preferably 200 °C, more preferably 180 °C, particularly preferably 160 °C, especially preferably 150 °C, and most preferably 120 °C. The blocking agent is affected by the additional heat during the drying step after coating the coating liquid or the film formation step when using the in-line coating method and dissociates from the functional group to generate a regenerated isocyanate group. Therefore, it undergoes a cross-linking reaction with a urethane resin or the like to improve adhesion. When the dissociation temperature of the blocked isocyanate is below the above temperature, the dissociation of the blocking agent proceeds sufficiently, so the adhesion becomes good, especially the moisture and heat resistance becomes good. In the present invention, as a blocking agent for a blocked isocyanate having a dissociation temperature of 120 °C or less and a boiling point of 150 °C or more, examples include: bisulfite compounds: sodium bisulfite, etc.; pyrazole compounds: 3,5-dimethylpyrazole, 3-methylpyrazole, 4-bromo-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, etc.; active methylene systems: malonic acid esters (dimethyl malonate, diethyl malonate, di-n-butyl malonate, di(2-ethylhexyl) malonate), methyl ethyl ketone, etc., triazole compounds: 1,2,4-triazole, etc. Among them, in terms of moisture and heat resistance and yellowing, pyrazole compounds are preferable. In the present invention, polyisocyanates having three or more functional groups as precursors of blocked isocyanates can be appropriately obtained by introducing isocyanate monomers. For example, there may be mentioned: biuret bodies, allophanate bodies, and adducts obtained by modifying isocyanate monomers such as aromatic diisocyanates, aliphatic diisocyanates, araliphatic diisocyanates, or alicyclic diisocyanates having two isocyanate groups. The so-called biuret body is a self-condensate having a biuret bond formed by the self-condensation of an isocyanate monomer. For example, a biuret body of hexamethylene diisocyanate may be mentioned. The so-called allophanate body is a trimer of an isocyanate monomer. For example, there may be mentioned: a trimer of hexamethylene diisocyanate, a trimer of isophorone diisocyanate, a trimer of toluene diisocyanate, etc. The so-called adduct is a polyisocyanate compound having three or more functional groups formed by reacting an isocyanate monomer with a compound having a low molecular weight active hydrogen and having three or more functional groups. For example, there may be mentioned: a compound obtained by reacting trimethylolpropane with hexamethylene diisocyanate, a compound obtained by reacting trimethylolpropane with toluene diisocyanate, a compound obtained by reacting trimethylolpropane with xylylene diisocyanate, a compound obtained by reacting trimethylolpropane with isophorone diisocyanate, etc. Examples of the isocyanate monomer include: aromatic diisocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, phenylene diisocyanate, tetramethylxylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyl diphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate; araliphatic diisocyanates such as xylylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, 4,4-dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane; aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate. In terms of transparency, adhesiveness, and resistance to wet heat, aliphatic isocyanates, alicyclic isocyanates, or modified products thereof are preferred. In the present invention, in order to impart water solubility or water dispersibility, a hydrophilic group can be introduced into a polyisocyanate as a precursor. Examples of the hydrophilic group include: (1) quaternary ammonium salts of dialkylamino alcohols or quaternary ammonium salts of dialkylaminoalkylamines; (2) sulfonates, carboxylates, phosphates, etc.; (3) polyethylene glycols, polypropylene glycols, etc. that are mono-terminally blocked with an alkyl group. When a hydrophilic moiety is introduced, it becomes (1) cationic, (2) anionic, or (3) nonionic. Among them, since most other water-soluble resins are anionic, it is preferably anionic or nonionic that can be easily miscible. In addition, the anionic type has excellent compatibility with other resins, and the nonionic type does not have an ionic hydrophilic group, so it is also preferable in terms of improving the wet heat resistance. As the anionic hydrophilic group, a hydroxyl group for introduction into the polyisocyanate or a carboxyl group for imparting hydrophilicity is preferable. For example, it includes glycolic acid, lactic acid, tartaric acid, citric acid, hydroxybutyric acid, oxyvaleric acid, hydroxypivalic acid, dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutyric acid, and polycaprolactone having a carboxyl group. For neutralizing the carboxyl group, an organic amine compound is preferable. For example, it includes ammonia; linear, branched primary amines, secondary amines, or tertiary amines having 1 to 20 carbon atoms such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, 2-ethylhexylamine, cyclohexylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, ethylenediamine; cyclic amines such as morpholine, N-alkylmorpholine, pyridine; hydroxyl group-containing amines such as monoisopropanolamine, methylethanolamine, methylisopropanolamine, dimethylethanolamine, diisopropanolamine, diethanolamine, triethanolamine, diethylethanolamine, triethanolamine, etc. As the nonionic hydrophilic group, the repeating units of ethylene oxide and / or propylene oxide of polyethylene glycol or polypropylene glycol that are mono-terminally blocked with an alkyl group are preferably 3 to 50, more preferably 5 to 30. When the repeating unit is small, the compatibility with the resin deteriorates and the haze increases. When the repeating unit is large, the adhesion at high temperature and high humidity sometimes decreases. In order to improve the water dispersibility of the blocked isocyanate of the present invention, nonionic, anionic, cationic, and amphoteric surfactants can be added. For example, it includes nonionic types such as polyethylene glycol and polyol fatty acid esters; anionic types such as fatty acid salts, alkyl sulfates, alkyl benzene sulfonates, sulfosuccinates, alkyl phosphates; cationic types such as alkylamine salts and alkyl betaines; surfactants such as carboxamide salts, sulfonamide salts, and sulfate esters. In addition, in addition to water, a water-soluble organic solvent can also be contained. For example, an organic solvent for the reaction can also be added, or the organic solvent for the reaction can be removed and other organic solvents can be added. The polyester resin used to form the coating layer in the present invention may also be linear, and more preferably a polyester resin composed of a dicarboxylic acid and a diol having a branched structure. The dicarboxylic acids mentioned here, in addition to terephthalic acid, isophthalic acid or 2,6-naphthalenedicarboxylic acid as the main components, include: aliphatic dicarboxylic acids such as adipic acid and sebacic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid. In addition, the so-called branched diol is a diol having a branched alkyl group, and examples thereof include: 2,2-dimethyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2-methyl-2-butyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-2-isopropyl-1,3-propanediol, 2-methyl-2-n-hexyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol, 2-ethyl-2-n-hexyl-1,3-propanediol, 2,2-di-n-butyl-1,3-propanediol, 2-n-butyl-2-propyl-1,3-propanediol, and 2,2-di-n-hexyl-1,3-propanediol, etc. Regarding the polyester resin, it is preferable that the branched diol component in the above-mentioned more preferred aspect is contained in the total diol component at a ratio of 10 mol% or more, and more preferably at a ratio of 20 mol% or more. If it is 10 mol% or less, the crystallinity may sometimes increase, resulting in a decrease in the adhesion of the coating layer. The upper limit of the diol component in the total diol component is preferably 80 mol% or less, and more preferably 70 mass%. If it is 80 mol% or more, the concentration of oligomers as by-products may sometimes increase, affecting the transparency of the coating layer. As the diol component other than the above-mentioned compounds, ethylene glycol is most preferred. If it is a small amount, diethylene glycol, propylene glycol, butylene glycol, hexylene glycol or 1,4-cyclohexanedimethanol, etc. may also be used. Regarding the dicarboxylic acid as a constituent of the above-mentioned polyester resin, terephthalic acid or isophthalic acid is most preferred. In addition to the above-mentioned dicarboxylic acids, in order to impart water dispersibility to the copolymerized polyester resin, it is preferable to copolymerize 5-sulfoisophthalic acid, etc. in the range of 1 mol% to 10 mol%, and examples thereof include: sulfoterephthalic acid, 5-sulfoisophthalic acid, 5-sodium sulfoisophthalic acid, etc. Polyester resins containing dicarboxylic acids having a naphthalene skeleton may also be used, but in order to suppress the decrease in the adhesion to UV ink, the amount ratio is preferably 5 mol% or less in the total carboxylic acid component, and it may not be used. When the total of the solids of the polyester resin, the urethane resin having a polycarbonate structure, and the crosslinking agent in the coating liquid is set to 100% by mass, the lower limit of the content rate of the crosslinking agent is preferably 5% by mass, more preferably 7% by mass, and particularly preferably 10% by mass. If it is 5% by mass or more, it is preferable because the adhesion resistance during water adhesion can be improved. The upper limit of the content rate of the crosslinking agent is preferably 50% by mass, more preferably 40% by mass, particularly preferably 35% by mass, and most preferably 30% by mass. If it is 50% by mass or less, it is preferable because the adhesion to the UV ink becomes high. When the total of the solids of the polyester resin, the urethane resin having a polycarbonate structure, and the crosslinking agent in the coating liquid is set to 100% by mass, the lower limit of the content rate of the urethane resin having a polycarbonate structure is preferably 5% by mass. If it is 5% by mass or more, it is preferable because the adhesion to the UV ink can be improved. The upper limit of the content rate of the urethane resin having a polycarbonate structure is preferably 50% by mass, more preferably 40% by mass, particularly preferably 30% by mass, and most preferably 20% by mass. If the content rate of the urethane resin is 50% by mass or less, it is preferable because the adhesion resistance during water adhesion can be improved. When the total of the solids of the polyester resin, the urethane resin, and the crosslinking agent in the coating liquid is set to 100% by mass, the lower limit of the polyester resin content rate is preferably 10% by mass, more preferably 20% by mass, particularly preferably 30% by mass, especially preferably 35% by mass, and most preferably 40% by mass. If the content rate of the polyester resin is 10% by mass or more, it is preferable because the adhesion between the coating layer and the polyester film substrate becomes good. The upper limit of the polyester resin content rate is preferably 70% by mass, more preferably 67% by mass, particularly preferably 65% by mass, especially preferably 62% by mass, and most preferably 60% by mass. If the content rate of the polyester resin is 70% by mass or less, it is preferable because the heat and humidity resistance after UV ink processing is good. [Additive] In the coating layer of the present invention, known additives such as surfactants, antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic particles, antistatic agents, nucleating agents, etc. may be added within the range that does not impair the effects of the present invention. In the present invention, when an antistatic agent is further contained in the composition for forming the coating layer, it is particularly preferable because it can prevent the occurrence of electrostatic failures in various steps for forming the obtained film into a label, such as the coating of an adhesive, printing, cutting, stamping, etc. As the antistatic agent, any of the following can be arbitrarily used within the range that does not impair the effects of the present invention: an antistatic agent generally used as a coating type antistatic agent (for example, a quaternary ammonium salt type antistatic agent); particulate carbon black; metal powders such as nickel and copper; metal oxides such as tin oxide and zinc oxide; fibrous metal-coated fibers such as brass, stainless steel, and aluminum; conductive fillers such as flaky graphite, aluminum flakes, and copper flakes; conductive polymers such as sulfonated polyaniline and polypyrrole. In order to reduce the glossiness of the coating surface, inactive particles may also be contained in the coating layer. Examples of the aforementioned inactive particles include inorganic particles such as titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silicon dioxide, aluminum oxide, talc, kaolin, clay, calcium phosphate, mica, lithium montmorillonite, zirconium oxide, tungsten oxide, lithium fluoride, calcium fluoride; or organic polymer particles such as polystyrene-based, polyacrylic acid-based, melamine-based, benzoguanamine-based, polysiloxane resin particles, etc. These may be one kind or two or more kinds may be used in combination. The average particle diameter of the aforementioned inactive particles is preferably 0.1 μm to 2.4 μm, more preferably 0.3 μm to 2.0 μm. If the average particle diameter of the inactive particles is 0.04 μm or less, there is a possibility that the glossiness of the film surface will increase. On the contrary, if it exceeds 2.4 μm, there is a tendency for the particles to fall off from the coating layer, resulting in powdering. Furthermore, the method for measuring the average particle diameter is as described above. Moreover, as long as the object of the present invention is satisfied, the shape of the particles is not particularly limited, and spherical particles or irregular non-spherical particles can be used. The particle diameter of the irregular particles can be calculated in the form of an equivalent circular diameter. When it is desired to increase the glossiness of the coating surface, it is preferable that the coating layer does not contain particles. [Manufacture of white laminated polyester film] The manufacturing method of the white laminated polyester film of the present invention is an arbitrary method and is not particularly limited. For example, the following general method can be used: After melting and extruding a mixture composed of the aforementioned composition into a sheet shape to form an unstretched film, the unstretched film is stretched. The white laminated polyester film of the present invention disperses a thermoplastic resin that is not compatible with the polyester resin in the polyester resin through the steps of melting and extruding the film raw material. In the examples of the present invention, the polyester resin and the thermoplastic resin that is not compatible with the polyester resin are resins supplied in a granular shape, but it is not limited thereto. The raw materials put into the extruder for melt-forming into a film shape are prepared by granulating and mixing these resins according to the target composition. However, when using a polyester resin and a polyolefin resin as the raw material of the porous polyester film of the present invention, since the specific gravity difference between the two resins is large, it is preferable to prevent segregation during the process of supplying the temporarily mixed granules to the extruder. Examples of preferable methods for preventing segregation include the following method: A part or all of the raw material resins are combined in advance and kneaded and granulated to form masterbatch granules. This method is used in the examples of the present invention, but as long as the effects of the present invention are not hindered, there is no particular limitation. In addition, in the extrusion of a mixed system of these incompatible resins, there is the following property: after being mixed and finely dispersed in a molten state, re-aggregation occurs due to the action of reducing the interfacial energy of the resins. This is the following phenomenon: when extruding a non-stretched film, a void-forming agent is coarsely dispersed, which hinders the expression of required physical properties. To prevent this phenomenon, it is preferable to use a twin-screw extruder with a higher mixing effect when forming the film of the present invention to preliminarily finely disperse the void-forming agent. In addition, when it is difficult to perform this operation, it is also preferable to supply the raw material resin from the extruder to the feed block or die via a static mixer as an auxiliary method. As the static mixer used here, a static mixer or an orifice or the like can be used. However, when these methods are adopted, the resin after thermal deterioration may sometimes remain in the melt line, and attention needs to be paid. Furthermore, the incompatible resin temporarily dispersed in the polyester resin in the form of fine particles has a tendency to re-aggregate the incompatible resin over time in a low-shear molten state. Therefore, the fundamental solution is to reduce the residence time in the melt line from the extruder to the die. In the present invention, it is preferable to set the residence time in the melt line to 30 minutes or less, and more preferably to 15 minutes or less. The conditions for stretching and orienting the non-stretched film obtained as described above are closely related to the physical properties of the film. Hereinafter, taking the most common sequential biaxial stretching method as an example, especially taking the method of stretching the non-stretched film in the longitudinal direction and then in the width direction as an example, the stretching and orienting conditions will be described. In the longitudinal stretching step, it is stretched 2.5 to 5.0 times in the longitudinal direction using rollers heated to 80°C to 120°C to obtain a uniaxially stretched film. As the heating method, it can be a method using heating rollers or a method using a non-contact heating method, or these can be used in combination. Then, the uniaxially stretched film is introduced into a tenter, and it is stretched 2.5 to 5.0 times in the width direction at a temperature of (Tm - 10°C) or lower. Here, Tm means the melting point of the polyester. In addition, the above-mentioned biaxially stretched film is heat-treated as needed. The heat treatment is preferably carried out in a tenter, and preferably carried out in the range of (Tm - 60°C) to Tm. The coating layer can be provided after the manufacture of the film or in the manufacturing step. Especially in terms of productivity, it is preferable to coat the coating liquid on at least one side of the PET (Polyethylene terephthalate) film after non-stretching or uniaxial stretching at any stage of the film manufacturing step to form a coating layer. The method for applying the coating liquid onto the PET film can use any known method. For example, the following can be cited: reverse roll coating method, gravure coating method, kiss coating method, die coater method, roller brush method, spray coating method, air knife coating method, wire bar coating method, tube knife coating method, dip coating method, curtain coating method, etc. These methods can be used for coating alone or in combination. In the present invention, the thickness of the coating layer can be appropriately set in the range of 0.001 μm to 2.00 μm. However, in order to have both processability and adhesiveness, it is preferably in the range of 0.01 μm to 1.00 μm, more preferably in the range of 0.02 μm to 0.80 μm, and particularly preferably in the range of 0.05 μm to 0.50 μm. If the thickness of the coating layer is 0.001 μm or more, the adhesiveness is good and it is preferable. If the thickness of the coating layer is 2.00 μm or less, it is less likely to cause adhesion and it is preferable. Conventionally, in polyester films having a coating layer containing a single type or a mixture of two or more types such as polyester resins, polyurethane resins, and acrylic resins, and a mixture of the foregoing resins and a specific crosslinking agent (such as melamine, isocyanate, etc.), most polyester films satisfy the anti-adhesion property when placed in a normal environment containing water vapor. However, in winter, condensation sometimes occurs during transportation between outdoors and indoors, causing liquid water to adhere to the film surface or the coating layer surface. At this time, there is a problem of adhesion in polyester films having a coating layer containing polyester resins, polyurethane resins, acrylic resins, and a crosslinking agent. However, the white laminated polyester film of the present invention not only has anti-adhesion property when placed in a normal environment containing water vapor, but also regarding the easy-to-adhere polyester film for transportation between indoors and outdoors in winter, even when condensation occurs due to changes in environmental temperature and liquid water adheres to the film surface or the coating layer surface, there is no risk of adhesion. [Examples] Next, the present invention will be described in detail using examples and comparative examples, but the present invention is not limited to the following examples. First, the evaluation methods used in the present invention will be described below. (1) Evaluation of adhesion resistance during water adhesion The easy - adherent polyester film produced by the following examples was cut into a width of 10 cm and a length of 1.5 cm in the long - side direction. At the end of the coated surface of the cut film, a film with a width of 1.5 cm and a length of 1.5 cm in the long - side direction was stacked. On the surface at the end on the side opposite to the coated layer, 0.03 g of water droplets were dropped. Then, the coated surfaces of the films cut into a width of 10 cm and a length of 1.5 cm in the long - side direction were overlapped with each other, and a roller was evenly applied from the side where the water droplets were dropped toward the side of the overlapping films without mixing air. Then, the sample was placed in an oven (50 °C) for 24 hours. Then, the films were peeled off, and the peeling state of the films was judged according to the following criteria. ○: It can be peeled off gently without transfer of the coating layer. △: The coating layer is maintained, but the surface layer of the coating layer is partially transferred to the target surface. ×: The two films are firmly adhered and cannot be peeled off, or even if they can be peeled off, the film substrate is cracked. (2) Adhesion to UV ink On the coating layer of the laminated polyester film, using UV ink [manufactured by T&K TOKA Co., Ltd., trade name "BEST CURE UV161 Blue S"], printing was carried out using a printing machine [manufactured by Meisei Seisakusho Co., Ltd., trade name "RI Tester"]. Subsequently, the film coated with the ink layer was irradiated with ultraviolet rays of 40 mJ / cm 2 from a high - pressure mercury lamp to cure the ultraviolet - curable ink. Subsequently, using a cellophane tape (CT405AP - 24) manufactured by Nichiban, a width of 24 mm and a length of 50 mm were cut out, and the cellophane tape was completely attached to the surface of the ink layer without mixing air using a handy gum roller. Then, the cellophane tape was vertically peeled off, and the remaining area of the printed layer was observed in a 24 mm×50 mm area, and judgment was made according to the following criteria. ○: The remaining area of the printed layer is 99% or more of the total. △: The remaining area of the printed layer is 90% or more but less than 99% of the total. ×: The remaining area of the printed layer is less than 90% of the total. (3) Method for measuring the number - average molecular weight of polycarbonate polyol When measuring a urethane resin having a polycarbonate structure by proton nuclear magnetic resonance spectroscopy (1H - NMR), a peak derived from the methylene adjacent to the OCOO bond is observed at around 4.1 ppm. In addition, at a magnetic field about 0.2 ppm higher than this peak, a peak derived from the methylene adjacent to the urethane bond generated by the reaction of polyisocyanate and polycarbonate polyol is observed. Based on the integral values of these two peaks and the molecular weights of the monomers constituting the polycarbonate polyol, the number - average molecular weight of the polycarbonate polyol is calculated. (4) Apparent density Cut the film into 4 squares with sides of 5.00 cm as specimens. Overlap 4 of these specimens and use a micrometer to make 10 measurements with 4 significant figures to find the average of the overlapping thickness. Divide this average by 4, round the fourth decimal place, and find the average film thickness per piece (t: μm) with the third decimal place. Additionally, measure the mass (w: g) of these 4 specimens with 4 significant figures using an automatic top-loading balance, and calculate the apparent density using the following formula. Furthermore, the apparent density is rounded to 3 significant figures. Apparent density (g / cm 3 ) = w × 10 4 / (5.00 × 5.00 × t × 4) (5) Optical density Use a Macbeth densitometer model TR-927 for the opacity of the polyester-based film to measure the light transmittance through a G filter, and calculate the optical density based on the obtained light transmittance as an indicator of opacity. The optical density is expressed as the logarithm (Log10) of the reciprocal of the light transmittance (range: 0 to 100%). The larger the value of the optical density, the higher the opacity. (6) L value, b value According to JIS (Japanese Industrial Standards) - 8722, use a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., ZE6000) to measure the reflected color L value and color b value. [Polymerization of urethane resin A-1 with a polycarbonate structure] Into a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer, add 27.5 parts by mass of hydrogenated isophthalic diisocyanate, 6.5 parts by mass of dimethylolpropionic acid, 60 parts by mass of polyhexamethylene carbonate diol with a number average molecular weight of 1800, 6 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent. Stir at 75 °C for 3 hours under a nitrogen atmosphere and confirm that the reaction solution reaches the predetermined amine equivalent. Then, add 5 parts by mass of trimethylolpropane and stir at 75 °C for 1 hour under a nitrogen atmosphere to confirm that the reaction solution reaches the predetermined amine equivalent. After cooling the reaction solution to 40 °C, add 5.17 parts by mass of triethylamine to obtain a polyurethane prepolymer solution. Then, add 450 g of water to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjust to 25 °C, and stir and mix while adding the polyurethane prepolymer solution for water dispersion at 2000 min -1 Stir and mix, and remove a part of acetone and water under reduced pressure to prepare an aqueous dispersion of urethane resin solution (A-1) with a solid content of 34% by mass. [Polymerization of urethane resin A-2 with a polycarbonate structure] In a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica drying tube, and a thermometer, 25 parts by mass of 4,4'-dicyclohexylmethane diisocyanate, 5 parts by mass of dimethylolpropionic acid, 52 parts by mass of polyhexamethylene carbonate diol with a number-average molecular weight of 2600, 6 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent were charged. The mixture was stirred at 75 °C for 3 hours under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Subsequently, 18 parts by mass of a polyisocyanate compound having an isocyanurate structure (manufactured by Asahi Kasei Chemicals, Duranate TPA, trifunctional) using hexamethylene diisocyanate as a raw material was added, and the mixture was stirred at 75 °C for 1 hour under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Then, the temperature of the reaction solution was lowered to 50 °C, and 8 parts by mass of methyl ethyl ketoxime was added dropwise. After the reaction solution was cooled to 40 °C, 5.17 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Subsequently, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjusted to 25 °C, and while stirring and mixing at 2000 min -1 The mixture was stirred and dispersed while adding the polyurethane prepolymer solution. Then, a part of acetone and water was removed under reduced pressure to prepare an aqueous dispersion of urethane resin (A-2) with a solid content of 35% by mass. [Polymerization of urethane resin A-3 with a polycarbonate structure] In a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica drying tube, and a thermometer, 22 parts by mass of 4,4'-dicyclohexylmethane diisocyanate, 20 parts by mass of polyethylene glycol monomethyl ether with a number-average molecular weight of 700, 53 parts by mass of polyhexamethylene carbonate diol with a number-average molecular weight of 2100, 5 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent were charged. The mixture was stirred at 75 °C for 3 hours under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Subsequently, 16 parts by mass of a polyisocyanate compound having an isocyanurate structure (manufactured by Asahi Kasei Chemicals, Duranate TPA, trifunctional) using hexamethylene diisocyanate as a raw material was added, and the mixture was stirred at 75 °C for 1 hour under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Then, the temperature of the reaction solution was lowered to 50 °C, and 7 parts by mass of methyl ethyl ketoxime was added dropwise. After the reaction solution was cooled to 40 °C, a polyurethane prepolymer solution was obtained. Subsequently, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjusted to 25 °C, and while stirring at 2000 min -1Stir and mix, and while adding the polyurethane prepolymer solution, perform water dispersion. Then, under reduced pressure, remove a part of acetone and water, thereby preparing an aqueous dispersible urethane resin solution (A-3) with a solid content of 35% by mass. [Polymerization of urethane resin A-4 having a polycarbonate structure] Into a four-necked flask equipped with a stirrer, Dimroth condenser, nitrogen inlet tube, silica gel drying tube, and thermometer, put 22 parts by mass of 4,4'-dicyclohexylmethane diisocyanate, 3 parts by mass of dimethylolbutyric acid, 73 parts by mass of polyhexamethylene carbonate diol with a number average molecular weight of 2000, 2 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent. Stir at 75 °C for 3 hours under a nitrogen atmosphere, and confirm that the reaction solution reaches the predetermined amine equivalent. Subsequently, put 4 parts by mass of trimethylolpropane, stir at 75 °C for 1 hour under a nitrogen atmosphere, and confirm that the reaction solution reaches the predetermined amine equivalent. Then, after cooling the reaction solution to 40 °C, add 8.77 parts by mass of triethylamine to obtain a polyurethane prepolymer solution. Subsequently, add 450 g of water to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjust the temperature to 25 °C, and while stirring at 2000 min -1 Stir and mix, and while adding the polyurethane prepolymer solution, perform water dispersion. Then, under reduced pressure, remove a part of acetone and water, thereby preparing an aqueous dispersible urethane resin solution (A-4) with a solid content of 34% by mass. [Polymerization of urethane resin A-5 having a polycarbonate structure] Into a four-necked flask equipped with a stirrer, Dimroth condenser, nitrogen inlet tube, silica gel drying tube, and thermometer, put 47 parts by mass of 4,4'-dicyclohexylmethane diisocyanate, 21 parts by mass of polyethylene glycol monomethyl ether with a number average molecular weight of 700, 20 parts by mass of polyhexamethylene carbonate diol with a number average molecular weight of 1200, 12 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent. Stir at 75 °C for 3 hours under a nitrogen atmosphere, and confirm that the reaction solution reaches the predetermined amine equivalent. Subsequently, put 4 parts by mass of trimethylolpropane, stir at 75 °C for 1 hour under a nitrogen atmosphere, and confirm that the reaction solution reaches the predetermined amine equivalent. Then, after cooling the reaction solution to 40 °C, add 8.77 parts by mass of triethylamine to obtain a polyurethane prepolymer solution. Subsequently, add 450 g of water to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjust the temperature to 25 °C, and while stirring at 2000 min -1 Stir and mix, and while adding the polyurethane prepolymer solution, perform water dispersion. Then, under reduced pressure, remove a part of acetone and water, thereby preparing an aqueous dispersible urethane resin solution (A-5) with a solid content of 34% by mass. [Polymerization of urethane resin A-6 having a polycarbonate structure] In a four-necked flask equipped with a stirrer, a Dean-Stark condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer, 23.5 parts by mass of 4,4'-dicyclohexylmethane diisocyanate, 4.5 parts by mass of dimethylolbutyric acid, 70 parts by mass of polyhexamethylene carbonate diol having a number-average molecular weight of 2000, 2 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent were charged. The mixture was stirred at 75 °C for 3 hours under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Then, after cooling the reaction solution to 40 °C, 8.77 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Subsequently, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, and the temperature was adjusted to 25 °C. While stirring and mixing at 2000 min -1 The mixture was stirred, and the polyurethane prepolymer solution was added for water dispersion. Then, a part of acetone and water was removed under reduced pressure to prepare an aqueous dispersion of urethane resin solution (A-6) having a solid content of 34% by mass. [Polymerization of urethane resin A-7 having a polycarbonate structure] In a four-necked flask equipped with a stirrer, a Dean-Stark condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer, 27.5 parts by mass of hydrogenated isophthalic acid dimethyl diisocyanate, 6.5 parts by mass of dimethylolpropionic acid, 60 parts by mass of polyhexamethylene carbonate diol having a number-average molecular weight of 1800, 6 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent were charged. The mixture was stirred at 75 °C for 3 hours under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. After cooling the reaction solution to 40 °C, 5.17 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Subsequently, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, and the temperature was adjusted to 25 °C. While stirring and mixing at 2000 min -1 The mixture was stirred, and the polyurethane prepolymer solution was added for water dispersion. Then, a part of acetone and water was removed under reduced pressure to prepare an aqueous dispersion of urethane resin solution (A-7) having a solid content of 34% by mass. [Polymerization of urethane resin A-8 with a polycarbonate structure] In a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica drying tube, and a thermometer, 400 parts by mass of a polycarbonate polyol with a number-average molecular weight of 2000 composed of 1,6-hexanediol and diethyl carbonate, 10.4 parts by mass of neopentyl glycol, 58.4 parts by mass of isophorone diisocyanate, 74.3 parts by mass of dimethylolbutyric acid, and 320 parts by mass of acetone as a solvent were charged. The mixture was stirred at 75 °C for 3 hours under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. After cooling the reaction solution to 40 °C, isophorone diamine was added to obtain a polyurethane prepolymer solution. Subsequently, 1200 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, and the temperature was adjusted to 25 °C. While stirring and mixing at 2000 min -1 The mixture was stirred and mixed while adding the polyurethane prepolymer solution for water dispersion. Then, a part of acetone and water was removed under reduced pressure to prepare a water-dispersible urethane resin solution (A-8) with a solid content of 34% by mass. [Polymerization of urethane resin A-9 with a polycarbonate structure] In a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica drying tube, and a thermometer, 50 parts by mass of 4,4'-dicyclohexylmethane diisocyanate, 21 parts by mass of polyethylene glycol monomethyl ether with a number-average molecular weight of 700, 35 parts by mass of polyhexamethylene carbonate diol with a number-average molecular weight of 1200, 13 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent were charged. The mixture was stirred at 75 °C for 3 hours under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Subsequently, 1.2 parts by mass of trimethylolpropane was added, and the mixture was stirred at 75 °C for 1 hour under a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Then, after cooling the reaction solution to 40 °C, 8.77 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Subsequently, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, and the temperature was adjusted to 25 °C. While stirring and mixing at 2000 min -1 The mixture was stirred and mixed while adding the polyurethane prepolymer solution for water dispersion. Then, a part of acetone and water was removed under reduced pressure to prepare a water-dispersible urethane resin solution (A-9) with a solid content of 34% by mass. [Polymerization of urethane resin A-10 without polycarbonate polyol component] 75 parts by mass of a polyester polyol with a molecular weight of 5000, composed of terephthalic acid, isophthalic acid, ethylene glycol, and neopentyl glycol, 30 parts by mass of hydrogenated isophthalic diisocyanate, 7 parts by mass of ethylene glycol, 6 parts by mass of dimethylolpropionic acid, and 84.00 parts by mass of acetone as a solvent were charged, and stirred at 75 °C for 3 hours in a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. After cooling the reaction solution to 40 °C, 5.17 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Subsequently, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjusted to 25 °C, and while stirring and mixing at 2000 min -1 the polyurethane prepolymer solution was added while stirring and mixing to perform aqueous dispersion. Then, a part of acetone and water was removed under reduced pressure to prepare an aqueous dispersion polyurethane resin solution (A-10) with a solid content of 34% by mass. [Polymerization of urethane resin A-11 without polycarbonate polyol component] 54 parts by mass of 4,4-dicyclohexylmethane diisocyanate, 38 parts by mass of a polyester polyol with a number average molecular weight of 1500 composed of ethylene glycol and adipic acid, 0.8 parts by mass of trimethylolpropane, and 84.00 parts by mass of acetone as a solvent were charged into a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer, and stirred at 75 °C for 3 hours in a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Subsequently, 4 parts by mass of sodium bisulfate was added and stirred at 75 °C for 1 hour in a nitrogen atmosphere to confirm that the reaction solution reached the predetermined amine equivalent. Then, after cooling the reaction solution to 40 °C, 8.77 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Subsequently, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjusted to 25 °C, and while stirring and mixing at 2000 min -1 the polyurethane prepolymer solution was added while stirring and mixing to perform aqueous dispersion. Then, a part of acetone and water was removed under reduced pressure to prepare an aqueous dispersion polyurethane resin solution (A-11) with a solid content of 34% by mass. [Polymerization of blocked isocyanate crosslinking agent B-1] In a flask equipped with a stirrer, a thermometer, and a reflux condenser, 95 parts by mass of 3,5-dimethylpyrazole (dissociation temperature: 120 °C, boiling point: 218 °C) was added dropwise to 66.04 parts by mass of a polyisocyanate compound having an isocyanurate structure (manufactured by Asahi Kasei Chemicals, Duranate TPA) using hexamethylene diisocyanate as a raw material and 17.50 parts by mass of N-methylpyrrolidone, and the mixture was maintained at 70 °C for 1 hour under a nitrogen atmosphere. Then, 30 parts by mass of dimethylolpropionic acid was added dropwise. The infrared spectrum of the reaction solution was measured, and after confirming the disappearance of the absorption of the isocyanate group, 5.59 parts by mass of N,N-dimethylethanolamine and 132.5 parts by mass of water were added to obtain a blocked polyisocyanate aqueous dispersion (B-1) having a solid content of 40% by mass. The blocked isocyanate crosslinking agent has a functional group number of 4 and an NCO equivalent of 280. [Polymerization of blocked isocyanate crosslinking agent B-2] In a flask equipped with a stirrer, a thermometer, and a reflux condenser, 100 parts by mass of a polyisocyanate compound having an isocyanurate structure (manufactured by Asahi Kasei Chemicals, Duranate TPA) using hexamethylene diisocyanate as a raw material, 55 parts by mass of propylene glycol monomethyl ether acetate, and 30 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 750) were charged, and the mixture was maintained at 70 °C for 4 hours under a nitrogen atmosphere. Then, the temperature of the reaction solution was lowered to 50 °C, and 47 parts by mass of methyl ethyl ketoxime was added dropwise. The infrared spectrum of the reaction solution was measured, and after confirming the disappearance of the absorption of the isocyanate group, 210 parts by mass of water was added to obtain an oxime-blocked isocyanate crosslinking agent (B-2) having a solid content of 40% by mass. The blocked isocyanate crosslinking agent has a functional group number of 3 and an NCO equivalent of 170. [Polymerization of carbodiimide B-3] In a flask equipped with a stirrer, a thermometer, and a reflux cooler, 168 parts by mass of hexamethylene diisocyanate and 220 parts by mass of polyethylene glycol monomethyl ether (M400, average molecular weight 400) were charged, and the mixture was stirred at 120 °C for 1 hour. Further, 26 parts by mass of 4,4'-dicyclohexylmethane diisocyanate and 3.8 parts by mass of 3-methyl-1-phenyl-2-phospholene-1-oxide as a carbodiimidization catalyst (2% by mass relative to the total isocyanate) were added, and the mixture was further stirred at 185 °C for 5 hours under a nitrogen stream. The infrared spectrum of the reaction solution was measured, and the absorption at wavelengths of 220 cm -1 to 2300 cm -1 was confirmed to have disappeared. The mixture was allowed to cool to 60 °C, and 567 parts by mass of ion-exchanged water was added to obtain a carbodiimide aqueous resin solution (B-3) having a solid content of 40% by mass. [Polymerization of blocked isocyanate crosslinking agent B-4] To 200 parts by mass of a polyester (molecular weight 2000) of 2 moles of ethylene oxide adduct of bisphenol A and maleic acid, 33.6 parts by mass of hexamethylene diisocyanate was added, and the reaction was carried out at 100 °C for 2 hours. Subsequently, the temperature of the system was temporarily lowered to 50 °C, 73 parts by mass of a 30% aqueous sodium bisulfite solution was added, and after stirring at 45 °C for 60 minutes, it was diluted with 718 parts by mass of water to obtain a blocked polyisocyanate aqueous dispersion (B-1) with a solids content of 20% by mass. The blocked isocyanate crosslinking agent has 2 functional groups and an NCO equivalent of 1300. [Polymerization of polyester resin C-1] In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 194.2 parts by mass of dimethyl terephthalate, 184.5 parts by mass of dimethyl isophthalate, 14.8 parts by mass of dimethyl 5-sodium sulfoisophthalate, 233.5 parts by mass of diethylene glycol, 136.6 parts by mass of ethylene glycol, and 0.2 parts by mass of tetra-n-butyl titanate were charged, and an ester exchange reaction was carried out at a temperature of 160 °C to 220 °C for 4 hours. Subsequently, the temperature was raised to 255 °C, the reaction system was slowly depressurized, and then reacted under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolymerized polyester resin (C-1). The obtained copolymerized polyester resin (C-1) was pale yellow and transparent. The reduced viscosity of the copolymerized polyester resin (C-1) was measured, and the result was 0.70 dl / g. The glass transition temperature obtained by DSC (Differential Scanning Calorimeter) was 40 °C. [Preparation of polyester aqueous dispersion Cw-1] In a reactor equipped with a stirrer, a thermometer, and a reflux device, 25 parts by mass of polyester resin (C-1) and 10 parts by mass of ethylene glycol n-butyl ether were added, and heated at 110 °C and stirred to dissolve the resin. After the resin was completely dissolved, 65 parts by mass of water was slowly added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to produce a milky white polyester aqueous dispersion (Cw-1) with a solids content of 25% by mass. [Polymerization of Polyester Resin C-2] In a stainless-steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 342.0 parts by mass of dimethyl 2,6-naphthalenedicarboxylate, 35.0 parts by mass of dimethyl terephthalate, 35.5 parts by mass of dimethyl 5-sodium sulfoisophthalate, 198.6 parts by mass of ethylene glycol, 118.2 parts by mass of 1,6-hexanediol, and 0.4 parts by mass of tetra-n-butyl titanate were charged, and a transesterification reaction was carried out at a temperature from 160 °C to 220 °C over 4 hours. Further, 60.7 parts by mass of sebacic acid was added to carry out an esterification reaction. Subsequently, the temperature was raised to 255 °C, and after slowly reducing the pressure of the reaction system, the reaction was carried out under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolyester resin (C-2). The obtained copolyester resin was pale yellow and transparent. [Preparation of Polyester Aqueous Dispersion Cw-2] In a reactor equipped with a stirrer, a thermometer, and a reflux device, 25 parts by mass of the copolyester resin (C-2) and 15 parts by mass of ethylene glycol n-butyl ether were added, and the mixture was heated and stirred at 110 °C to dissolve the resin. After the resin was completely dissolved, 55 parts by mass of water was slowly added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to produce a milky white polyester aqueous dispersion (Cw-2) with a solids content of 25% by mass. [Polymerization of Polyester Resin C-3] In a stainless-steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 194.2 parts by mass of dimethyl terephthalate, 184.5 parts by mass of dimethyl isophthalate, 14.8 parts by mass of dimethyl 5-sodium sulfoisophthalate, 185 parts by mass of neopentyl glycol, 188 parts by mass of ethylene glycol, and 0.2 parts by mass of tetra-n-butyl titanate were charged, and a transesterification reaction was carried out at a temperature from 160 °C to 220 °C over 4 hours. Subsequently, the temperature was raised to 255 °C, and after slowly reducing the pressure of the reaction system, the reaction was carried out under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolyester resin (C-3). The obtained copolyester resin (C-3) was pale yellow and transparent. The reduced viscosity of the copolyester resin (C-3) was measured, and the result was 0.40 dl / g. The glass transition temperature obtained by DSC was 65 °C. [Preparation of Polyester Aqueous Dispersion Cw-3] In a reactor equipped with a stirrer, a thermometer, and a reflux device, 25 parts by mass of the polyester resin (C-3) and 10 parts by mass of ethylene glycol n-butyl ether were added, and the mixture was heated and stirred at 110 °C to dissolve the resin. After the resin was completely dissolved, 65 parts by mass of water was slowly added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to produce a milky white polyester aqueous dispersion (Cw-3) with a solids content of 25% by mass. [Example 1] (1) Preparation of coating liquid In a mixed solvent of water and isopropyl alcohol, the following coating agents were mixed to prepare a coating liquid in which the solid mass ratio of urethane resin solution (A-1) / crosslinking agent (B-1) / polyester aqueous dispersion (Cw-1) was 25 / 26 / 49. Urethane resin solution (A-1) 6.30 parts by mass Crosslinking agent (B-1) 5.50 parts by mass Polyester aqueous dispersion (Cw-1) 17.00 parts by mass Particles 23.00 parts by mass (silica particles with an average particle diameter of 0.45 μm, solid concentration 40.00% by mass) Surfactant 0.15 parts by mass (polysiloxane-based, solid concentration 10% by mass) (2) Manufacture of white laminated polyester film [Preparation of masterbatch] A particle mixture of 60% by mass of a polymethylpentene resin (manufactured by Mitsui Chemicals, DX820) with a melt viscosity (ηO) of 1,300 poise, 20% by mass of a polystyrene resin (manufactured by Nippon Polystyrene Co., Ltd., G797N) with a melt viscosity (ηS) of 3,900 poise, and 20% by mass of a polypropylene resin (manufactured by Grand Polymer Co., Ltd., J104WC) with a melt viscosity of 2,000 poise was supplied to a vented twin-screw extruder heated to 285°C for premixing. The molten resin was continuously supplied to a vented single-screw kneader, kneaded and extruded, and the resulting strand was cooled and cut to prepare a void-expressing agent masterbatch (M1). In addition, a mixture obtained by mixing 50% by mass of anatase titanium dioxide particles (manufactured by Fuji Titanium Co., Ltd., TA-300) with an average particle diameter of 0.3 μm in 50% by mass of a polyethylene terephthalate resin with an intrinsic viscosity of 0.62 dl / g manufactured by a known method was supplied to a vented twin-screw extruder for premixing. The molten resin was continuously supplied to a vented single-screw kneader, kneaded and extruded. The resulting strand was cooled and cut to prepare a titanium dioxide-containing masterbatch (M2). [Preparation of film raw material] 81% by mass of the above-mentioned polyethylene terephthalate resin with an intrinsic viscosity of 0.62 dl / g that had been vacuum-dried at 140°C for 8 hours, 9% by mass of the above-mentioned masterbatch (M1) that had been vacuum-dried at 90°C for 4 hours, and 10% by mass of the above-mentioned masterbatch (M2) were granulated and mixed to prepare a film raw material (C1). [Production of Unstretched Film] The aforementioned film raw material (C1) was supplied to the extruder for layer B heated to 285°C, and a mixture of 70% by mass of polyethylene terephthalate resin identical to the polyethylene terephthalate resin used in the film raw material (C1) and 30% by mass of the above masterbatch (M2) was supplied to the extruder for layer A heated to 290°C. The molten resin discharged from the extruder for layer B was introduced into the feed block through the orifice. Additionally, the resin discharged from the extruder for layer A was introduced into the feed block through the static mixer. The layer composed of the film raw material (C1) (layer B) and the layer composed of polyethylene terephthalate resin and masterbatch (M2) (layer A) were laminated in the order of layer A / layer B / layer A. The molten resin was co-extruded from the T-die in sheet form onto a cooling roll heated to 25°C, and closely cured by the electrostatic application method to produce an unstretched film with a thickness of 510 μm. Furthermore, the discharge amounts of the respective extruders were adjusted such that the thickness ratio of each layer was 1:8:1. At this time, the residence time of the molten resin in the melt line was approximately 12 minutes, and the shear rate received from the T-die was about 150 / second. [Production of Biaxially Stretched Film] The obtained unstretched film was uniformly heated to 65°C using a heating roll and longitudinally stretched 3.4 times between two pairs of nip rolls with different peripheral speeds (low-speed roll: 2 m / min, high-speed roll: 6.8 m / min). At this time, as an auxiliary heating device for the film, an infrared heater equipped with a metal reflection film (rated output: 20 W / cm) was disposed at a position 1 cm away from the film surface facing both sides of the film in the middle part of the nip rolls for heating. On one side of the uniaxially stretched film thus obtained, the aforementioned coating liquid was coated by the reverse kiss coating method such that the resin solid content thickness before stretching became 0.9 μm. After coating, it was introduced into a tenter, heated to 150°C while drying and transversely stretched 3.7 times, width-fixed, and heat-treated at 220°C for 5 seconds, and further relaxed 4% in the width direction at 200°C to obtain a white laminated polyester film with a thickness of 50 μm. The apparent density of this film is 1.10 g / cm 3 , and the optical density is 0.8. The evaluation results are shown in Table 1. [Example 2] The urethane resin of the coating liquid was changed to (A-2), and the polyester aqueous dispersion was changed to (Cw-3). Otherwise, a white laminated polyester film was obtained in the same manner as in Example 1. [Example 3] (1) Preparation of Coating Liquid The urethane resin was changed to (A-3), and otherwise, the coating liquid was prepared in the same manner as in Example 1. (2) Manufacture of white laminated polyester film [Preparation of masterbatch] A mixture obtained by mixing 50% by mass of titanium dioxide anatase type having an average particle diameter of 0.3 μm (electron microscopy method) in 50% by mass of polyethylene terephthalate resin having an intrinsic viscosity of 0.62 was supplied to a vent type twin-screw extruder and kneaded to produce a masterbatch (M3) containing titanium oxide. [Production of unstretched film] 85% by mass of polyethylene terephthalate resin having an intrinsic viscosity of 0.62, 10% by mass of polypropylene resin having MFR (Melt Flow Rate) = 2.5, Mw = 320,000, Mw / Mn = 4.0, and heat deflection temperature = 92°C, and 5% by mass of the aforementioned masterbatch (M3) containing titanium oxide were mixed and vacuum dried to produce a raw material for a polyester B layer containing voids. On the other hand, 30% by mass of the aforementioned masterbatch (M3) containing titanium oxide and 70% by mass of polyethylene terephthalate resin having an intrinsic viscosity of 0.62 were granule-mixed and vacuum dried to produce a raw material for a polyester A layer containing inorganic particles. These raw materials were supplied to respective extruders, melted at 285°C, and the polyester B layer containing voids and the polyester A layer containing inorganic particles were laminated in the order of A / B / A, joined using a feedblock so that the thickness ratio became 10 / 80 / 10, and extruded from a T-die onto a cooling drum adjusted to 30°C to produce an unstretched film having a two-layer three-layer structure. [Production of biaxially stretched film] The obtained unstretched film was uniformly heated to 70°C using a heating roller and longitudinally stretched 3.4 times between two pairs of nip rollers having different peripheral speeds. At this time, as an auxiliary heating device for the film, an infrared heater (rated output: 20 W / cm) equipped with a metal reflection film was disposed facing both sides of the film (at a distance of 1 cm from the film surface) in the middle part of the nip rollers for heating. On one side of the uniaxially stretched film thus obtained, the above coating liquid was coated by the reverse kiss coating method so that the resin solid content thickness before stretching became 0.9 μm. After coating, it was introduced into a tenter, heated to 140°C while drying and laterally stretched 4.0 times, width-fixed, heat-treated at 235°C, and further relaxed 3% in the width direction at 210°C to obtain a white laminated polyester film having a thickness of 50 μm. The apparent density of this film is 1.09 g / cm 3 , the optical density is 0.6, the L value is 94.4, and the b value is 1.6. [Example 4] The crosslinking agent of the coating liquid was changed to (B-2), and a white laminated polyester film was obtained in the same manner as in Example 1 except for this. [Example 5] The urethane resin of the coating liquid was changed to (A-2), and the crosslinking agent was changed to (B-2), and a white laminated polyester film was obtained in the same manner as in Example 1 except for this. [Example 6] A white laminated polyester film was obtained in the same manner as in Example 1, except that the urethane resin of the coating liquid was changed to (A-3) and the crosslinking agent was changed to (B-2). [Example 7] In the coating liquid, the following coating agents were mixed in a mixed solvent of water and isopropyl alcohol, and the solid mass ratio of urethane resin solution (A-2) / total crosslinking agents (B-1, B-2) / polyester aqueous dispersion (Cw-1) was changed to 25 / 26 / 49. Otherwise, a white laminated polyester film was obtained in the same manner as in Example 1. Urethane resin solution (A-2) 6.30 parts by mass Crosslinking agent (B-1) 3.73 parts by mass Crosslinking agent (B-2) 1.77 parts by mass Polyester aqueous dispersion (Cw-1) 17.00 parts by mass Particles 23.00 parts by mass (silica particles with an average particle diameter of 0.45 μm, solid concentration 40.00% by mass) Surfactant 0.15 parts by mass (silicone-based, solid concentration 10% by mass) [Example 8] A white laminated polyester film was obtained in the same manner as in Example 7, except that the urethane resin of the coating liquid was changed to (A-3) and the polyester aqueous dispersion was changed to (Cw-3). [Example 9] In the coating liquid, the following coating agents were mixed in a mixed solvent of water and isopropyl alcohol, and the solid mass ratio of urethane resin solution (A-3) / crosslinking agent (B-2) / polyester aqueous dispersion (Cw-1) was changed to 27 / 14 / 59. Otherwise, a white laminated polyester film was obtained in the same manner as in Example 1. Urethane resin solution (A-3) 7.00 parts by mass Crosslinking agent (B-2) 3.00 parts by mass Polyester aqueous dispersion (Cw-1) 21.00 parts by mass Particles 23.00 parts by mass (silica particles with an average particle diameter of 0.45 μm, solid concentration 40.00% by mass) Surfactant 0.15 parts by mass (silicone-based, solid concentration 10% by mass) Antistatic agent 2.00 parts by mass (quaternary ammonium salt-based antistatic agent, solid concentration 17.50% by mass) [Example 10] In the coating solution, the following coating agents were mixed in a mixed solvent of water and isopropyl alcohol, and the solid matter mass ratio of urethane resin solution (A-3) / crosslinking agent (B-2) / polyester aqueous dispersion (Cw-1) was changed to 28 / 11 / 61. Otherwise, a white laminated polyester film was obtained in the same manner as in Example 1. Urethane resin solution (A-3) 12.00 parts by mass Crosslinking agent (B-2) 4.00 parts by mass Polyester aqueous dispersion (Cw-1) 35.00 parts by mass Particles 27.00 parts by mass (melamine formaldehyde condensate particles with an average particle diameter of 2 μm, solid content concentration 40.00% by mass) Surfactant 0.15 parts by mass (silicone-based, solid content concentration 10% by mass) Antistatic agent 2.00 parts by mass (quaternary ammonium salt-based antistatic agent, solid content concentration 17.50% by mass) [Example 11] In the coating solution, the following coating agents were mixed in a mixed solvent of water and isopropyl alcohol, and the solid matter mass ratio of urethane resin solution (A-1) / crosslinking agent (B-1) / polyester aqueous dispersion (Cw-1) was changed to 22 / 10 / 68. Otherwise, a laminated polyester film was obtained in the same manner as in Example 1. Urethane resin solution (A-1) 5.80 parts by mass Crosslinking agent (B-1) 2.20 parts by mass Polyester aqueous dispersion (Cw-1) 24.00 parts by mass Particles 23.00 parts by mass (silica particles with an average particle diameter of 0.45 μm, solid content concentration 40.00% by mass) Surfactant 0.15 parts by mass (silicone-based, solid content concentration 10% by mass) [Example 12] The urethane resin in the coating solution was changed to (A-2). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Example 13] The urethane resin in the coating solution was changed to (A-3). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Example 14] The crosslinking agent in the coating solution was changed to (B-3), and the polyester aqueous dispersion was changed to (Cw-3). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Example 15] The urethane resin in the coating solution was changed to (A-4). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Example 16] The urethane resin in the coating solution was changed to (A-5). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Example 17] The urethane resin in the coating solution was changed to (A-3), and the crosslinking agent was changed to (B-2). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Example 18] The urethane resin of the coating solution was changed to (A-3), and the particles were changed to calcium carbonate particles with an average particle diameter of 1 μm (solid content concentration: 40.00% by mass). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Example 19] The urethane resin of the coating solution was changed to (A-9). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Comparative Example 1] The urethane resin of the coating solution was changed to (A-6). Otherwise, a laminated polyester film was obtained in the same manner as in Example 1. [Comparative Example 2] The urethane resin of the coating solution was changed to (A-7). Otherwise, a laminated polyester film was obtained in the same manner as in Example 1. [Comparative Example 3] The urethane resin of the coating solution was changed to (A-6). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Comparative Example 4] The urethane resin of the coating solution was changed to (A-7). Otherwise, a laminated polyester film was obtained in the same manner as in Example 11. [Comparative Example 5] The solid mass ratio of the urethane resin solution (A-6) / crosslinking agent (B-1) / polyester aqueous dispersion (Cw-2) in the coating solution was changed to 38 / 7 / 55. Otherwise, a laminated polyester film was obtained in the same manner as in Example 1. [Comparative Example 6] The solid mass ratio of the urethane resin solution (A-8) / crosslinking agent (B-4) / polyester aqueous dispersion (Cw-2) in the coating solution was changed to 22 / 12 / 66. Otherwise, a laminated polyester film was obtained in the same manner as in Example 1. As shown in Table 1, in each of the examples, results were obtained that could satisfy the adhesion resistance during water adhesion and the adhesion to UV ink. On the other hand, in Comparative Examples 1 to 6, since the coating layer formed on at least one surface of the polyester film substrate did not contain a urethane resin having a branched structure, the adhesion resistance during water adhesion could not be satisfied. [Comparative Example 7] In the coating solution, the following coating agents were mixed in a mixed solvent of water and isopropyl alcohol, and the solid ratio of the urethane resin solution (A-1) / crosslinking agent (B-1) was changed to 70 / 30. Otherwise, a laminated polyester film was obtained in the same manner as in Example 1. Urethane resin solution (A-1) 15.00 parts by mass Crosslinking agent (B-1) 5.50 parts by mass Particles 23.00 parts by mass (silica particles with an average particle diameter of 0.45 μm, solid content concentration: 40.00% by mass) Surfactant 0.15 parts by mass (polysiloxane-based, solid content concentration: 10% by mass) [Comparative Example 8] In the coating solution, the following coating agents were mixed in a mixed solvent of water and isopropyl alcohol, and the solid content ratio of the urethane resin solution (A-1) / crosslinking agent (B-1) was changed to 20 / 80. Otherwise, a laminated polyester film was obtained in the same manner as in Example 1. Urethane resin solution (A-1) 4.70 parts by mass Crosslinking agent (B-1) 16.00 parts by mass Particles 23.00 parts by mass (Silica particles with an average particle diameter of 0.45 μm, solid content concentration 40.00% by mass) Surfactant 0.15 parts by mass (Silicone-based, solid content concentration 10% by mass) As shown in Table 1, in Comparative Example 7 and Comparative Example 8, since the coating layer formed on at least one surface of the polyester film substrate does not contain a polyester resin, the adhesion between the coating layer and the substrate is reduced, and the adhesion to UV ink cannot be satisfied. [Comparative Example 9] The urethane resin was changed to (A-10), and otherwise, a laminated polyester film was obtained in the same manner as in Example 1. [Comparative Example 10] The urethane resin was changed to (A-11), and otherwise, a laminated polyester film was obtained in the same manner as in Example 11. As shown in Table 1, in Comparative Example 9 and Comparative Example 10, since the coating layer formed on at least one surface of the polyester film substrate does not contain a urethane resin having a polycarbonate structure, the adhesion to UV ink cannot be satisfied. The evaluation results of each example and comparative example are summarized in Table 1. [Table 1] [Industrial Applicability] According to the present invention, it is possible to provide a white laminated polyester film suitable for use in fields such as label applications.

Claims

1. A white laminated polyester film having a coating layer on at least one side of a polyester resin layer, the coating layer being formed by curing a composition comprising an amino carboxylate resin having a polycarbonate structure and a branched structure, a crosslinking agent, and a polyester resin; wherein the polyester resin is composed of dicarboxylic acid and a branched alkyl diol, and the branched alkyl diol is contained in the total diol composition at a ratio of 20 mol% to 80 mol%.

2. The white laminated polyester film as described in claim 1, wherein the aforementioned crosslinking agent is a compound having a blocked isocyanate group with three or more functions.

3. The white laminated polyester film as described in claim 1 or 2, wherein the aforementioned polycarbonate structure and branched structure of the urethane resin is synthesized and polymerized from polycarbonate polyol component, polyisocyanate component and compound having hydroxyl or isocyanate group with 3 or more functions, wherein the mass ratio of polycarbonate polyol component to polyisocyanate component during the aforementioned synthesis and polymerization (mass of polycarbonate polyol component / mass of polyisocyanate component) is 0.5 to 3.