JP2014125599A - Aqueous adhesive for forming easily adhesive layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous adhesive for forming an easily adhesive layer which can form an easily adhesive film that is especially excellent in adhesiveness with an acrylic coat layer, and is excellent in transparency, blocking resistance and water resistance.SOLUTION: An aqueous adhesive for forming an easily adhesive layer contains a polyester resin (A) which is mainly constituted by a dicarboxylic acid component and a glycol component, a basic compound and water, and does not substantially contain an emulsifier. The polyester resin (A) has an acid number of 4 mgKOH/g or more, a glass transition temperature of 40-75°C, and has a number average molecular weight of 5,000-50,000. The content of the dicarboxylic acid having a sulfonate group as the dicarboxylic acid component constituting the polyester resin (A) is less than 1 mol%.

Description

  The present invention relates to a water-based adhesive for forming an easy adhesion layer comprising a polyester resin as a main component.

  Polyester films, especially biaxially stretched films of polyethylene terephthalate and polyethylene naphthalate, have excellent mechanical properties, heat resistance, chemical resistance, and transparency. For magnetic tapes, photographic films, packaging films, and electronic parts. It is widely used as a material for films, optical films, surface protective films and the like. These films are frequently used by laminating a magnetic layer, a photosensitive layer, a protective layer, an intermediate layer, a colored layer and the like, and affixing or sticking to another adherend.

  Recently, in optical applications, especially displays (LCD and CRT), a film in which a hard coat layer, antireflection layer and antifouling layer are laminated on a polyester film is affixed to the display surface and is used for screen protection purposes. Yes.

In general, the components constituting the hard coat layer have low adhesion to the polyester film, and surface treatment of the polyester film has been performed when the hard coat layer is laminated.
As the surface treatment, physical treatment such as corona treatment is known, but these treatments are insufficient for improving the adhesion of the hard coat agent. That is, when a polyester film laminated with a hard coat layer is used under severe environmental conditions, for example, in an environment of a rapid temperature change (thermal shock), the adhesion between the hard coat layer and the film layer may be reduced and peeled off. In addition, the adhesiveness was lowered by the resin component of the hard coat layer to be laminated, and it was not fully satisfactory.

  On the other hand, a method of forming a hard coat layer on the easy-adhesion layer after providing an easy-adhesion layer in advance on the surface of the polyester film before laminating the hard coat layer is known (for example, Patent Document 1). . As the easy adhesion layer, for example, an aqueous dispersed polyester resin or the like is used.

JP 2001-281423 A

  In the polyester resin aqueous dispersion as used as the easy adhesion layer, for example, in the polyester resin aqueous dispersion in which the aqueous dispersion is performed using a hydrophilic component such as 5-sodium sulfoisophthalic acid, The hydrophilic component will remain significantly, and there has been a problem in transparency and adhesiveness deterioration particularly in a high humidity environment. Furthermore, by containing dicarboxylic acid having a sulfonate group such as 5-sulfoisophthalic acid, the dilution stability of the adhesive and the mixing stability with the additive are inferior, and metal molecules remain in the film. There was a problem.

An object of the present invention is to provide a water-based adhesive for forming an easy-adhesion layer, which is particularly excellent in adhesion to an acrylic coating layer, and can form an easy-adhesion film excellent in transparency, blocking resistance and water resistance. And
Furthermore, it becomes possible to provide a polyester film having excellent adhesion to a photocurable resin typified by a hard coating agent as an acrylic coating layer.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.

  That is, the gist of the present invention is as follows.

(1) A polyester resin (A) mainly composed of a dicarboxylic acid component and a glycol component, a basic compound and water, and an aqueous adhesive for forming an easy adhesion layer substantially free of an emulsifier, wherein the polyester The resin (A) has an acid value of 4 mgKOH / g or more, a glass transition temperature of 40 to 75 ° C., a number average molecular weight of 5000 to 50000, and a dicarboxylic acid having a sulfonate group as a dicarboxylic acid component constituting the polyester resin (A) A water-based adhesive for forming an easily adhesive layer, characterized in that the content of is less than 1 mol%.
(2) Furthermore, a polyurethane resin (B) is contained, and the polyester resin (A) and the polyurethane resin (B) are contained in a ratio of (A) / (B) = 99/1 to 40/60 (mass ratio). (2) The water-based adhesive for forming an easily adhesive layer.
(3) The water-based adhesive for forming an easy adhesion layer according to (2), wherein the polyurethane resin (B) is a polyether type polyurethane resin.
(4) The water based adhesive for forming an easy adhesion layer according to (3), wherein the polyether polyol component of the polyether type polyurethane resin is polytetramethylene glycol.
(5) The easily adhesive layer forming water-based adhesive according to (3) or (4), wherein the isocyanate component of the polyether type polyurethane resin is isophorone diisocyanate.
(6) The water-based adhesive for forming an easy adhesion layer according to (1) to (5), further comprising inorganic particles (C).
(7) An easy-adhesion film obtained by removing an aqueous medium from the aqueous adhesive for forming an easy-adhesion layer according to (1) to (6).
(8) A laminate obtained by forming the easy-adhesion film of (7) on a substrate.
(9) The laminate according to (8), wherein an acrylic coating film is further provided on the coating film.

ADVANTAGE OF THE INVENTION According to this invention, the water-based adhesive for easy-adhesion layer formation which is excellent in especially adhesiveness with an acrylic-type coating layer, and can form the easily-adhesive film excellent in transparency, blocking resistance, and water resistance is obtained.
Moreover, the laminated body containing the film using such a water-based adhesive can be suitably used for applications such as an outermost layer film for liquid crystal display and an outermost layer film of a touch panel.

Hereinafter, the present invention will be described in detail.
The water-based adhesive for forming an easy adhesion layer of the present invention contains at least a polyester resin (A), and may contain a polyurethane resin (B) and inorganic particles (C) described later.

  The polyester resin (A) of the present invention is mainly composed of a dicarboxylic acid component and a glycol component.

  In the dicarboxylic acid component, the content of the dicarboxylic acid having a sulfonate group needs to be less than 1 mol%, more preferably less than 0.5 mol%, and further preferably 0 mol%. preferable. When the content of the dicarboxylic acid having a sulfonate group is 1 mol% or more, the water resistance of the film obtained from the water-based adhesive for easily bonding layer formation is greatly reduced. In general, a polyester resin containing a dicarboxylic acid having a sulfonate group can be easily dispersed in an aqueous medium without using an emulsifier, but the water resistance of the coating is significantly reduced.

  Examples of the dicarboxylic acid having a sulfonate group include 5-sodium sulfoisophthalic acid, 5-sodium sulfoterephthalic acid, 5-potassium sulfoisophthalic acid, 5-potassium sulfoterephthalic acid, 5-lithium sulfoisophthalic acid, and 5-lithium. Sulfoterephthalic acid, sodium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, sodium 2,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, 3,5-di (carbo-β-) Hydroxyethoxy) benzenebenzenesulfonate, lithium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, dimethyl 5-sodium sulfoisophthalate, dimethyl 5-sodium sulfoterephthalate, dimethyl 5-potassium sulfoisophthalate, 5- Dimethylthiazol-ium sulfoisophthalic acid.

  In the dicarboxylic acid component, the dicarboxylic acid component other than the dicarboxylic acid having a sulfonate group can be used without particular limitation as long as it does not impair the characteristics of the present invention. Examples of such dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 3-tert-butylisophthalic acid, diphenic acid and other aromatic dicarboxylic acids, Saturated aliphatic dicarboxylic acids such as acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, hydrogenated dimer acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid Unsaturated aliphatic dicarboxylic acids such as itaconic anhydride, citraconic acid, citraconic anhydride, dimer acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5 -Norbornene dicarboxylic acid and its anhydride, tetrahydrophthalic acid and its They include alicyclic dicarboxylic acids of things such as, among others, it is preferable to use a saturated aliphatic dicarboxylic acids and aromatic dicarboxylic acids. When an aromatic dicarboxylic acid is used as the dicarboxylic acid component, there is an effect of improving the alcohol resistance of the resin film obtained from the water-based adhesive for forming an easy adhesion layer. Moreover, when using a saturated aliphatic dicarboxylic acid component as a dicarboxylic acid component, there exists an effect which improves the workability of the resin film obtained from the water-based adhesive for easy-bonding layer formation. The total content of the aromatic dicarboxylic acid component and the saturated aliphatic dicarboxylic acid component in the dicarboxylic acid component is preferably 90 to 100 mol%. At that time, the ratio of the aromatic dicarboxylic acid component to the saturated aliphatic dicarboxylic acid component is (aromatic dicarboxylic acid component) / (saturated aliphatic dicarboxylic acid component) = 70/30 to 95/5 (molar ratio). Is more preferable, and it is more preferable that it is 73 / 27-93 / 7 (molar ratio), and it is further more preferable that it is 75 / 25-90 / 10 (molar ratio).

  Examples of the glycol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neo Pentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, aliphatic glycols such as 2-ethyl-2-butylpropanediol, 1,4-cyclohexanedimethanol , Alicyclic glycols such as 1,3-cyclobutanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol and other glycols containing ether bonds, 2,2-bis [4- (Hydroxye ) Phenyl] alkylene oxide adducts of propane, bis [4- (hydroxyethoxy) phenyl] sulfone of the alkylene oxide adducts thereof. These glycol components may be used alone or in combination.

  In the present invention, a hydroxycarboxylic acid component may be contained within a range that does not impair the properties of the water-based adhesive for easily bonding layer formation of the present invention. Examples of the hydroxycarboxylic acid include 2-hydroxy sebacic acid, 5-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, citric acid, isocitric acid, malic acid, 2-methyl-2-hydroxysuccinic acid, tartaric acid, tetrahydroxyadipine Examples thereof include alkylene oxide adducts of acid, ε-caprolactone, δ-valerolactone, γ-valerolactone, lactic acid, β-hydroxybutyric acid, p-hydroxybenzoic acid, and 4-hydroxyphenyl stearic acid. When using hydroxymonocarboxylic acid, the content is preferably 50 mol% or less, more preferably 40 mol% or less, and more preferably 30 mol% or less, out of the total 100 mol% of the constituent components. More preferably.

  The polyester resin used in the present invention may contain a monocarboxylic acid and a monoalcohol as long as the characteristics of the present invention are not impaired. When monocarboxylic acid and monoalcohol are used, the content thereof is preferably less than 1 mol% and less than 0.1 mol%, respectively, with respect to 100 mol% of the dicarboxylic acid component and glycol component. More preferably, it is more preferably 0 mol%. Generally, when a monocarboxylic acid and a monoalcohol are charged before the esterification reaction and the polycondensation reaction proceeds, the extension of the molecular chain is inhibited, and as a result, the necessary molecular weight cannot be obtained. Therefore, the resin film obtained therefrom may be insufficient in film forming properties. On the other hand, when monocarboxylic acid or monoalcohol is used at the time of depolymerization, the acid value necessary for the present invention may not be obtained because it binds to the end of the molecular chain.

  Examples of the monocarboxylic acid include benzoic acid, phenylacetic acid, lauric acid, palmitic acid, stearic acid, and oleic acid. Examples of the monoalcohol include cetyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, octyl. Examples include alcohol and stearyl alcohol.

  The polyester resin used in the present invention may contain a trifunctional or higher functional carboxylic acid or a trifunctional or higher functional alcohol as long as the characteristics of the present invention are not impaired. When the trifunctional or higher functional carboxylic acid or the trifunctional or higher functional alcohol is charged before the esterification reaction, the content is preferably 5% by mole or less with respect to 100% by mole of the dicarboxylic acid component or the glycol component, respectively. It is more preferably 4 mol% or less, and further preferably 3 mol% or less. Generally, when tri- or higher-functional carboxylic acid or tri- or higher-functional alcohol is charged before the esterification reaction and the polycondensation reaction proceeds, the resulting polyester resin can be dispersed more widely or gelled for polymerization. In some cases, the content of the dicarboxylic acid component and the glycol component is preferably 0 to 1 mol%, and preferably 0 to 0.8 mol%. More preferably, it is more preferably 0 to 0.6 mol%. Moreover, when using trifunctional or more carboxylic acid and trifunctional or more alcohol at the time of depolymerization, the content shall be 0.2-5 mol% with respect to 100 mol% of dicarboxylic acid components or glycol components, respectively. It is preferably 0.4 to 4.8 mol%, more preferably 0.6 to 4.6 mol%.

  Examples of the tri- or higher functional carboxylic acid include trimellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, trimesic acid, ethylene glycol bis (anhydrotrimethyl). And glycerol tris (anhydro trimellitate), 1,2,3,4-butanetetracarboxylic acid, and trifunctional or higher alcohols include, for example, glycerin, trimethylolethane, trimethylolpropane, An example is pentaerythritol.

  The acid value of the polyester resin used in the present invention is required to be 4 mg KOH / g or more, and preferably 4 to 40 mg KOH / g in order to improve the stability of the water-based adhesive for forming an easy adhesion layer. More preferably, it is 4-20 mgKOH / g. When the acid value of the polyester resin is less than 4 mgKOH / g, it is difficult to uniformly disperse in an aqueous medium, or even if it can be dispersed, the stability of the water-soluble adhesive for forming an easy adhesion layer is inferior. Absent.

  As a glass transition temperature of the polyester resin used by this invention, it is necessary to set it as 40-75 degreeC, It is preferable that it is 45-70 degreeC, and it is more preferable that it is 50-65 degreeC. By setting the glass transition temperature to 40 to 75 ° C., the resin film obtained from the water-based adhesive for forming an easy adhesion layer has excellent blocking resistance and easy adhesion. When the glass transition temperature of the polyester resin is less than 40 ° C., the resin film obtained from the water-based adhesive for easily bonding layer formation is inferior in blocking resistance. When the glass transition temperature exceeds 75 ° C., the resulting resin film has poor easy adhesion.

  The number average molecular weight of the polyester resin used in the present invention needs to be 5,000 to 50,000, preferably 5,000 to 30,000, in order to improve the film forming property and adhesiveness of the resulting resin film. 30000 is more preferable, and 9000 to 25000 is even more preferable. When the number average molecular weight of the polyester resin is less than 5000, the film forming property and adhesiveness of the resin film are inferior, which is not preferable. When the number average molecular weight exceeds 50,000, the storage stability of the aqueous dispersion is deteriorated, which is not preferable.

  The dispersity in the molecular weight distribution of the polyester resin used in the present invention (hereinafter sometimes abbreviated as “dispersion degree”) is preferably 2 to 10, more preferably 2 to 9, and more preferably 2 More preferably, it is -8. The degree of dispersion is a value obtained by dividing the weight average molecular weight by the number average molecular weight. By setting the degree of dispersion to 2 to 10, it is possible to suppress a decrease in the film forming property and adhesiveness of the resin film. It is difficult to design a polyester resin having a dispersity of less than 2.

  Next, the manufacturing method of a polyester resin is demonstrated.

  The polyester resin used in the present invention can be produced by a known method by combining the above monomers. For example, all the monomer components and / or low polymers thereof are reacted in an inert atmosphere to carry out an esterification reaction, followed by polycondensation reaction in the presence of a polycondensation catalyst under reduced pressure until the desired molecular weight is reached. There can be mentioned a method of carrying out a depolymerization reaction by adding a trifunctional or higher functional carboxylic acid under an inert atmosphere.

  In the esterification reaction, the reaction temperature is preferably 180 to 260 ° C., and the reaction time is preferably 2.5 to 10 hours, more preferably 4 to 6 hours.

  In the polycondensation reaction, the reaction temperature is preferably 220 to 280 ° C. The degree of vacuum is preferably 130 Pa or less. If the degree of vacuum is low, the polycondensation time may be long. It is preferable to gradually reduce the pressure over 60 to 180 minutes until the atmospheric pressure reaches 130 Pa or less.

  Although it does not specifically limit as a polycondensation catalyst, Well-known compounds, such as a zinc acetate, an antimony trioxide, a tetra- n-butyl titanate, n-butylhydroxy oxo tin, can be mentioned. It is preferable that the usage-amount of a catalyst shall be 0.1-20 * 10 <-4> mol with respect to 1 mol of dicarboxylic acid components.

  In the depolymerization, the reaction temperature is preferably 160 to 280 ° C, more preferably 160 to 220 ° C, and the reaction time is preferably 0.5 to 5 hours.

  Next, the polyester resin aqueous dispersion of the present invention will be described.

  The aqueous polyester resin dispersion of the present invention is an emulsion obtained by dispersing a polyester resin in an aqueous medium. Here, the aqueous medium is a medium made of a liquid containing water, and may contain an organic solvent or a basic compound.

  The aqueous polyester resin dispersion of the present invention should contain substantially no emulsifier. The emulsifier as used in the present invention includes a surfactant, a compound having a protective colloid effect, a modified wax, an acid-modified product having a high acid value, a water-soluble polymer, and the like. In the present invention, “substantially does not contain” means that no emulsifier is actively added during the production of the aqueous polyester resin dispersion of the present invention, resulting in the absence of these. . The content of such an emulsifier is preferably zero, but may be less than 0.1 parts by mass with respect to 100 parts by mass of the polyester resin component as long as the effects of the present invention are not impaired. When the aqueous dispersion contains 0.1 part by mass or more of an emulsifier, the water resistance of the resin film is lowered. By using an emulsifier, the polyester resin can be easily dispersed in an aqueous medium. On the other hand, such a formulation significantly impairs water resistance.

  Examples of the surfactant include a cationic surfactant, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant. Examples of the anionic surfactant include sulfate esters of higher alcohols, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfates. Salt, vinyl sulfosuccinate. Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide-propylene oxide copolymer Examples thereof include compounds having a polyoxyethylene structure such as coalescence and sorbitan derivatives. Examples of amphoteric surfactants include lauryl betaine and lauryl dimethylamine oxide.

  Examples of the compound having a protective colloid effect include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, and polyvinyl pyrrolidone.

  Examples of the modified waxes include acid-modified polyolefin waxes having a number average molecular weight of 5000 or less, such as carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax, carboxyl group-containing polyethylene-propylene wax, and salts thereof.

  In the aqueous polyester resin dispersion of the present invention, the content of the polyester resin is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, and 15 to 40% by mass. Further preferred. Handling property improves by making the content rate of a polyester resin into 5-50 mass%. In addition, since the dispersed polyester resin is less likely to aggregate, storage stability is improved.

  The aqueous polyester resin dispersion of the present invention preferably has a pH of 6 or more, more preferably 7 or more, and even more preferably 8 or more. When the pH is 6 or more, the dispersed polyester resin is less likely to aggregate, so that the storage stability of the aqueous dispersion is improved.

  In the aqueous polyester resin dispersion of the present invention, the volume average particle size of the polyester resin fine particles is preferably less than 200 nm, more preferably less than 150 nm, further preferably less than 100 nm, and more preferably less than 50 nm. Most preferred. By setting the volume average particle diameter to less than 200 nm, the dispersed polyester resin is less likely to aggregate, so that the storage stability of the aqueous dispersion is improved. The volume average particle diameter can be controlled by the amount of organic amine and the reaction temperature during phase inversion emulsification, as will be described later.

  Next, the manufacturing method of the polyester resin aqueous dispersion is demonstrated.

  The aqueous polyester resin dispersion in the present invention is produced by a method in which the carboxyl group of the above polyester resin is at least partially or completely neutralized with a basic compound to be dispersed in an aqueous medium. By neutralizing the carboxyl group, a carboxyl anion is generated, and the dispersed polyester resin is less likely to aggregate due to the electric repulsive force between the anions and can exist stably.

  Examples of the method for producing an aqueous polyester resin dispersion in the present invention include a phase inversion emulsification method and a self-emulsification method. The phase inversion emulsification method is a polyester resin aqueous dispersion in which a polyester resin is dissolved in an organic solvent (dissolution step), and a basic compound and water are added to the polyester resin solution (phase inversion emulsification step). Can be suitably used for a wider range of polyester resins. The self-emulsification method is a method in which a polyester resin, a basic compound, an organic solvent, and water are charged together and heated while stirring the system to obtain an aqueous polyester resin dispersion containing the organic solvent. Thus, an aqueous dispersion can be obtained more easily.

  As used herein, “phase inversion emulsification” refers to adding an amount of water exceeding the amount of organic solvent contained in this solution to an organic solvent solution of a polyester resin, and changing the system of the organic solvent solution from the organic solvent phase to O / It is to change to a W emulsion dispersion system.

  In the dissolving step, the polyester resin is dissolved in an organic solvent to obtain an organic solvent solution of the polyester resin. If the polyester resin is difficult to dissolve, it may be dissolved by heating.

  As an apparatus used in the dissolution step, for example, any apparatus may be used as long as it has a tank into which a liquid can be charged and can be appropriately stirred. Such devices include those known as solid / liquid stirring devices and emulsifiers (eg homomixers).

  In the phase inversion emulsification step, an organic solvent solution of the polyester resin is dispersed in an aqueous medium together with the basic compound to obtain an aqueous polyester resin dispersion. Phase inversion emulsification may be performed under any conditions of normal pressure, reduced pressure, and increased pressure.

  The reaction temperature in the phase inversion emulsification step is preferably 10 to 40 ° C, more preferably 10 to 30 ° C, still more preferably 15 to 30 ° C, and most preferably 15 to 20 ° C. preferable. By setting the reaction temperature to 10 to 40 ° C., it is possible to suppress an increase in the viscosity of the contents during the phase inversion emulsification step, and thus it is possible to easily produce a uniform aqueous dispersion having good storage stability. it can. In addition, there exists a tendency for a volume average particle diameter to become small, so that the reaction temperature of a phase inversion emulsification process is low.

  The input speed of the aqueous medium in the phase inversion emulsification step is not particularly limited, but is preferably 25 to 100 parts by mass / min with respect to 1000 parts by mass in total of the polyester resin solution and the basic compound, and 30 to 95. It is more preferable to set it as a mass part / min, and it is still more preferable to set it as 35-90 mass part / min. By making the input speed of the aqueous medium 25 to 100 parts by mass / minute, it is possible to uniformly disperse the polyester resin while suppressing the formation of a lump of polyester resin.

  The solid content concentration of the polyester resin aqueous dispersion after phase inversion emulsification is preferably 5 to 60% by mass, more preferably 10 to 55% by mass, and still more preferably 15 to 50% by mass. . By setting the solid content concentration of the aqueous polyester resin dispersion to 5 to 60% by mass, aggregation of the polyester resin can be suppressed in the subsequent solvent removal step.

  The apparatus used for the phase inversion emulsification step and the solvent removal step may be any device that includes a tank into which a liquid can be charged, can be controlled to a temperature within the above-described range, and can be appropriately stirred.

  Examples of the organic solvent used in the production of the aqueous polyester resin dispersion include, for example, ketone organic solvents, aromatic hydrocarbon organic solvents, ether organic solvents, halogen-containing organic solvents, alcohol organic solvents, and ester organic solvents. And known ones such as glycol organic solvents. Examples of the ketone organic solvent include methyl ethyl ketone, acetone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, 2-hexanone, 5-methyl-2-hexanone, cyclopentanone, and cyclohexanone. Examples of the aromatic hydrocarbon organic solvent include toluene, xylene, benzene and the like. Examples of the ether organic solvent include dioxane and tetrahydrofuran. Examples of the halogen-containing organic solvent include carbon tetrachloride, trichloromethane, dichloromethane, and the like. Examples of the alcohol organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl. Examples include alcohol, 1-ethyl-1-propanol, and 2-methyl-1-butanol. Examples of the ester organic solvent include ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid-sec-butyl, acetic acid-3-methoxybutyl, and methyl propionate. . Examples of the glycol organic solvent include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether. , Diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate and the like. Further, organic solvents such as 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol and the like can also be used. In addition, you may use the organic solvent to be used individually or in combination of 2 or more types.

  The organic solvent used in the production of the aqueous polyester resin dispersion preferably has a boiling point of 180 ° C. or lower, more preferably 165 ° C. or lower, and even more preferably 150 ° C. or lower. When the boiling point of the organic solvent exceeds 180 ° C., it becomes difficult to completely remove the organic solvent in the solvent removal step, the organic solvent tends to remain in the aqueous dispersion, the storage stability decreases, and the remaining organic Water resistance may be reduced by the solvent. Moreover, it may be difficult to evaporate the organic solvent from the resin film by drying.

  As for the said organic solvent, it is more preferable that the azeotropic point with water is 60-150 degreeC. When the azeotropic point with water exceeds 150 ° C., it becomes difficult to completely remove the organic solvent in the solvent removal step, the organic solvent tends to remain in the aqueous dispersion, the storage stability decreases, and the residue remains. The water resistance may decrease due to the organic solvent. Moreover, it may be difficult to evaporate the organic solvent from the resin film by drying. When the azeotropic point with water is less than 60 ° C., a time difference occurs between volatilization of the azeotrope and volatilization of water, and the film forming property of the resulting resin film may be inferior.

  Furthermore, it is more preferable that the organic solvent has a solubility in water at 20 ° C. of 5 g / L or more. If the solubility of the organic solvent in water is less than 5 g / L, the polyester resin aqueous dispersion may not be obtained.

  Examples of such an organic solvent include ethyl acetate (solubility: about 12 g / L, boiling point: 77.1 ° C., azeotropic point: 70.4 ° C.), n-propanol (solubility: infinite, boiling point: 97 .2 ° C., azeotropic point: 87.7 ° C., isopropanol (solubility: infinite, boiling point: 82.4 ° C., azeotropic point: 80.2 ° C.), methyl ethyl ketone (solubility: minimum about 290 g / L, boiling point: 79.6 ° C., azeotropic point: 73.4 ° C., tetrahydrofuran (solubility: infinity, boiling point: 66.0 ° C., azeotropic point: 64.0 ° C.), 1,4-dioxane (solubility: infinity, Boiling point: 101 ° C., azeotropic point: 87.8 ° C., cyclohexanone (solubility: about 110 g / L, boiling point: 156 ° C., azeotropic point: 95.0 ° C.), ethylene glycol monoethyl ether (solubility: infinite, Boiling point: 136 ° C., azeotropic point with water: 99. ℃), and the like. These may be used alone or in combination.

  As an organic solvent for dissolving the polyester resin in the dissolving step, the concentration of the polyester resin in the resulting solution is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, 30 More preferably, it is made into 50 mass%. By setting the concentration of the polyester resin in the solution to 10 to 70% by mass, an increase in viscosity at the time of mixing with water in the next phase inversion emulsification step is suppressed, so that the volume average particle size of the aqueous dispersion is large. It can be suppressed.

  In the self-emulsification method, an aqueous dispersion with higher dispersion efficiency and stability can be easily produced by controlling the content ratio of the organic solvent to be used. For example, when isopropanol is used as the organic solvent, the content ratio of isopropanol in the aqueous dispersion is preferably 17 to 27% by mass, more preferably 18 to 26% by mass, and 19 to 25% by mass. More preferably.

  The basic compound used in the production of the aqueous polyester resin dispersion is preferably one capable of neutralizing the carboxyl group. Examples of such basic compounds include ammonia, ethylamine, diethylamine, dibutylamine, triethylamine, propylamine, isopropylamine, iminobispropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, diethanolamine, and triethanol. Examples thereof include organic amines such as amine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, morpholine, N-methylmorpholine, and N-ethylmorpholine. Examples of the basic compound include metal hydroxides such as lithium hydroxide, potassium hydroxide, and sodium hydroxide, but the water resistance of the film obtained from the aqueous dispersion may be insufficient.

  As the basic compound, a tertiary amine is more preferable because it can suppress the hydrolysis reaction of the polyester resin in the aqueous dispersion as much as possible in the production process.

  Furthermore, since it is easy to volatilize a basic compound from a polyester resin film, it is more preferable to use a basic compound having a boiling point of 150 ° C. or less. Examples of such basic compounds include ammonia, triethylamine, and N, N-dimethylethanolamine.

  The basic compound is preferably added in an amount of 0.5 to 30 times equivalent, more preferably 0.8 to 25 times, and more preferably 1 to 20 times the acid value of the polyester resin used. Is more preferable. By adding the basic compound in an amount of 0.5 to 30 times the acid value of the polyester resin, an aqueous dispersion having good storage stability can be obtained. In addition, there exists a tendency for volume average particle diameter to become small, so that the quantity of a basic compound is large.

  In the production of an aqueous polyester resin dispersion, a step of removing an organic solvent and / or a basic compound (desolvent step) may be further provided after each of the above emulsification steps, and a phase inversion emulsification method is used. It is preferable to provide a solvent removal step because the stability is improved. The content of the organic solvent after the desolvation step is preferably less than 1% by mass of the aqueous dispersion, more preferably less than 0.5% by mass, and further preferably less than 0.3% by mass. preferable.

  In the solvent removal step, the aqueous polyester resin dispersion containing the organic solvent and the basic compound is heated to remove the organic solvent and / or the basic compound to obtain an aqueous polyester resin dispersion. Solvent removal may be performed under normal pressure or reduced pressure.

  In the production of the aqueous polyester resin dispersion, a filtration step for removing undispersed matter and aggregates by filtration may be appropriately provided. For example, a 600-mesh stainless steel filter (filtration accuracy: 25 μm, twill) may be installed, and atmospheric pressure filtration or pressure (air pressure 0.2 MPa) filtration may be performed.

  The water-based adhesive for forming an easy-adhesion layer of the present invention can further contain a polyurethane resin (B) in order to improve easy-adhesion.

  The polyurethane resin (B) of the present invention is a polymer containing a urethane bond in the main chain, and is obtained, for example, by a reaction between a polyol component and a polyisocyanate component.

  As the polyurethane resin (B) in the present invention, a polyether type polyurethane resin is preferably used. The polyether type polyurethane resin is composed of polyether polyol as a polyether component and various diisocyanates as a polyisocyanate component, for example, aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate.

  Examples of the polyether polyol constituting the polyether type polyurethane resin include polyoxyethylene polyol such as polyethylene glycol, polyoxypropylene polyol such as polypropylene glycol, and polyoxyethylene / propylene polyol such as polytetramethylene ether glycol. Can be mentioned. Among them, polyether diols such as polyethylene glycol and polytetramethylene glycol are preferable because they are easily available, and polytetramethylene glycol is more preferable because adhesion is improved. Although the number average molecular weight of polyether diol is not specifically limited, It is preferable that it is 1000-20000, It is more preferable that it is 2000-17000, It is further more preferable that it is 3000-15000. When a polyol other than the polyether polyol is used, it can be used within a range that does not impair the effects of the present invention. For example, 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1 , 3-propanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, methyl-1,5-pentanediol, 1,8-octanediol, 2-ethyl-1,3-hexane Diol etc. are mentioned.

  Examples of the diisocyanate as the polyisocyanate component constituting the polyether type polyurethane resin include, for example, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5 -Naphthalene diisocyanate, isophorone diisocyanate, dimethyl diisocyanate, lysine diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, dimer isocyanate obtained by converting the carboxyl group of dimer acid to an isocyanate group, and adducts and biurets thereof , Isocyanurate and the like. These can be used alone or in combination of two or more. Among the above diisocyanates, by using isophorone diisocyanate, it becomes possible to further improve the water resistance of the coating film, especially the transparency of the coating film under high humidity, and further the transparency after laminating the hard coat. Can be improved. In particular, it has a remarkable effect on improvement of wet heat durability.

  When using a polyurethane resin (B) for the water-based adhesive for forming an easy-adhesion layer of the present invention, it is preferable to use it as an aqueous dispersion of the polyurethane resin (B) from the viewpoint of the working environment. Further, the aqueous dispersion of the polyester resin (A) and the aqueous dispersion of the polyurethane resin (B) can be easily mixed, and in order to obtain a uniform aqueous adhesive for forming an easy adhesion layer, the polyurethane resin (B ) Aqueous dispersion can be suitably used.

  There is no restriction | limiting in particular in the manufacturing method of the aqueous dispersion of a polyurethane resin (B), What is necessary is just to use a general method. For example, a polyol compound, a hydrophilic compound, and a polyisocyanate compound are reacted to form an isocyanate-terminated prepolymer, and then a polyurethane resin (B) aqueous dispersion is obtained by mixing the reaction liquid and water. Can do.

  The water-based adhesive for forming an easy-adhesion layer of the present invention can further contain inorganic particles (C) in order to improve the slipperiness.

  Examples of the inorganic particles (C) that can be blended in the aqueous adhesive for forming an easy-adhesion layer of the present invention include silica, talc, mica, kaolin, swellable fluoromica, montmorillonite, hectorite, calcium carbonate, magnesium carbonate, and calcium oxide. Zinc oxide, magnesium oxide, sodium silicate, aluminum hydroxide, iron oxide, zirconium oxide, barium sulfate, titanium oxide, carbon black and the like. Of these, silica, talc, mica, and kaolin are preferred because they are highly effective in exhibiting heat resistance and transparency of the resulting coating, and silica is most preferred because of excellent slipperiness.

Silica that can be preferably used in the present invention is mainly composed of silicon dioxide represented by SiO ₂ , and is roughly classified into two types, that is, wet method silica and dry method silica, depending on the production method. Can also be used. Dry silica is generally made by flame hydrolysis. Specifically, a method of making silicon tetrachloride by burning with hydrogen and oxygen is generally known, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone or silicon tetrachloride instead of silicon tetrachloride. Can be used in a mixed state. On the other hand, wet method silica is further classified into precipitation method silica, gel method silica, and sol method silica according to the production method. Precipitated silica is produced by reacting sodium silicate and sulfuric acid under alkaline conditions, and the silica on which particles have grown is agglomerated and settled, and is then commercialized through filtration, water washing, drying, pulverization and classification. The secondary particles of silica produced by this method become loose agglomerated particles, and particles that are relatively easy to grind are obtained. Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. During the ripening, the fine particles dissolve and reprecipitate so as to bind other primary particles, so that the distinct primary particles disappear and form relatively hard aggregated particles having an internal void structure. The sol method silica is also called colloidal silica, and is obtained by heating and aging a silica sol obtained through metathesis of sodium silicate acid or the like through an ion exchange resin layer.

  The average particle diameter of the inorganic particles (C) is not particularly limited, but is preferably 0.1 μm or more and 20 μm or less, more preferably 0.5 μm or more and 15 μm or less, and more preferably 1 μm or more and 10 μm. More preferably, it is as follows. When the average particle size is 0.1 μm, it becomes difficult to uniformly disperse in the dispersion, and the effect of slipperiness cannot be sufficiently exhibited. When the average particle diameter exceeds 20 μm, not only the slipperiness becomes insufficient but also the transparency tends to be impaired.

  The inorganic particles (C) may be surface-treated with a reactive compound such as a silane coupling agent, a titanate coupling agent, or an organosiloxane as necessary. In particular, a silane coupling agent can be suitably used. For example, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-mercaptopropyl Examples include trimethoxysilane.

  The method for obtaining the water-based adhesive for easily bonding layer formation of the present invention is not particularly limited. For example, (1) an aqueous dispersion of polyester resin (A), an aqueous dispersion of polyurethane resin (B), inorganic particles ( C) A method of mixing and stirring an aqueous dispersion of (2) After mixing the polyester resin (A) and the polyurethane resin (B) in advance, and then adding and dispersing them in an aqueous medium in a lump, and then dispersing the aqueous dispersion of inorganic particles. The method of adding etc. is mentioned. Among these, the method (1) is most preferable because the stability of the aqueous adhesive is sufficiently improved.

  The blend of the polyester resin (A) and the polyurethane resin (B) in the water-based adhesive for forming an easy adhesion layer of the present invention is (A) / (B) = 99/1 to 40/60 (mass ratio). Is preferable, it is more preferable that it is 95 / 5-45 / 55 (mass ratio), and it is further more preferable that it is 90 / 10-50 / 50. When it is within the above range, the water resistance and easy adhesion property of the resulting resin film are further improved.

  The inorganic particles (C) are blended in {(A) + (B)} / (C) with respect to the total mass (A) + (B) of the polyester resin (A) and the polyurethane resin (B). = 99/1 to 90/10 (mass ratio) is preferable, 99/1 to 92/8 (mass ratio) is more preferable, and 99/1 to 95/5 (mass ratio). Is more preferable. When the inorganic particles (C) are contained in the above mass ratio, the resulting resin film can be further provided with easy slipperiness.

  The water-based adhesive for forming an easily adhesive layer of the present invention can further contain other optional components. Examples of optional components that can be blended include a curing agent, a leveling agent, an antifoaming agent, other thickeners, a color pigment, water, and alcohol.

  Examples of the curing agent that can be used in the present invention include amino resins such as urea resin, melamine resin, and benzoguanamine resin, polyfunctional epoxy compounds, polyfunctional isocyanate compounds and various block isocyanate compounds thereof, polyfunctional aziridine compounds, and carbodiimide groups. A containing compound, an oxazoline group-containing polymer, a phenol resin, and the like. You may use 1 type of these, or may use 2 or more types together. By adding a hardening | curing agent, the resin film obtained can further provide solvent resistance. It is preferable that the non-volatile component of the aqueous adhesive of this invention is 1-10 mass parts with respect to 100 mass parts, as for the mixing | blending of a hardening | curing agent, it is more preferable that it is 1-8 mass parts, and 1-5 mass. More preferably, it is a part.

  Examples of the leveling agent that can be used in the present invention include silicone-based and fluorine-based leveling agents. In particular, the silicone-based leveling agent is compatible with the coating liquid, coating suitability, adhesion, and anti-blocking properties. It is preferable from the property. Examples of the silicone leveling agent include reactive silicone, polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane. By using a leveling agent, it is possible to improve the wettability during coating and to improve the smoothness of the coating film. The blending of the leveling agent is preferably 1 to 15 parts by mass, more preferably 1 to 13 parts by mass with respect to 100 parts by mass of the aqueous adhesive of the present invention, and 1 to 10 parts by mass. More preferably.

  As an antifoamer which can be used by this invention, an acetylene glycol type compound and its ethylene oxide adduct are preferable, for example. Specifically, 3,6-dimethyl-4-decyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol and compounds obtained by adding ethylene oxide thereto Is effective. By using an antifoaming agent, the generation of bubbles mixed in the dispersion during coating can be suppressed, and the smoothness and transparency of the resulting coating film can be improved. The amount of the antifoaming agent is preferably 1 to 10 parts by mass, more preferably 1 to 8 parts by mass, and 1 to 5 parts by mass with respect to 100 parts by mass of the aqueous adhesive of the present invention. Is more preferable.

  The water-based adhesive for forming an easy adhesion layer of the present invention can form a coating film on various substrates using a known coating method.

  The thickness of the easy-adhesion layer obtained with the aqueous adhesive for forming an easy-adhesion layer of the present invention is preferably 0.05 to 3 μm, more preferably 0.1 to 2.5 μm, 0.5 More preferably, it is ˜2 μm. When the thickness of the easy adhesion layer is less than 0.05 μm, it is difficult to sufficiently improve the easy adhesion performance, and when it exceeds 3 μm, the transparency is impaired.

  Examples of the method for forming a resin film using the aqueous adhesive of the present invention include a spray coating method, a spin coating method, a bar coating method, a curtain flow coating method, a dipping method, a brush coating method, and the like. By coating uniformly on the surface of various substrates, setting it near room temperature as necessary, and then subjecting it to heat treatment for drying and baking, a uniform coating film is formed in close contact with the support surface Can do. As a heating device at this time, a normal hot air circulation type oven, an infrared heater, or the like may be used. In addition, the heating temperature and the heating time are appropriately selected depending on the type of support to be coated, but considering the economy, the heating temperature is usually 60 to 250 ° C. 70-230 degreeC is preferable and 80-200 degreeC is more preferable. The heating time is usually 1 second to 120 minutes, preferably 5 seconds to 100 minutes, and more preferably 10 seconds to 60 minutes.

  Examples of the substrate for forming the resin coating include a polyester film, a nylon film, a polypropylene film, and a vinyl chloride film. Especially, a polyester film can be used suitably at the point which is excellent in heat resistance and transparency and can fully improve adhesiveness with the water-based adhesive for easy-bonding layer formation of this invention.

  The polyester constituting the polyester film used in the present invention is a linear saturated polyester obtained by polycondensation from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of such polyesters include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, polyethylene-2, 6 naphthalene dicarboxylate, and the like, and these copolymers or a small proportion of other resins. Blends and the like are also included.

  The polyester film can be produced by a conventionally known method. For example, the biaxially stretched polyester film is obtained by drying the polyester, melting it with an extruder at a temperature of Tm to (Tm + 70) ° C. (Tm: melting point of the polyester), and from a die (eg, T-die, I-die, etc.). Extruded onto a rotating cooling drum, rapidly cooled at 40 to 90 ° C. to produce an unstretched film, and then the unstretched film was subjected to a temperature of (Tg-10) to (Tg + 70) ° C. (Tg: glass transition temperature of polyester) Stretch in the longitudinal direction at a magnification of 2.5 to 8.0 times, stretch in the transverse direction at a magnification of 2.5 to 8.0 times, and heat for 1 to 60 seconds at a temperature of 180 to 250 ° C. as necessary. It can be manufactured by fixing.

  The thickness of the polyester film is preferably in the range of 5 to 250 μm. When the thickness of the film is less than 5 μm, there is a problem that the deformation resistance (dimensional stability) in a high temperature range is inferior, and when it exceeds 250 μm, the rigidity is too high.

  If necessary, an appropriate filler can be contained in the polyester film. Examples of the filler include those conventionally known as slipperiness imparting agents for polyester films, and specific examples thereof include calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide, zinc oxide, carbon black, carbonized carbon. Examples thereof include silicon, tin oxide, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles, and crosslinked silicone resin particles. Further, a colorant, an antistatic agent, an antioxidant, an organic lubricant, a catalyst, and the like can be appropriately added to the polyester.

  The polyester film used in the present invention has at least one easy adhesion layer on at least one side or both sides on the polyester film.

  As the method for producing the easily-adhesive polyester film of the present invention, the coating solution is applied to a stretched film and then dried (post-coating), or the coating solution is applied to a film before biaxial orientation crystallization is completed. Then, after drying and stretching in at least one direction, heat treatment (pre-coating) and the like can be mentioned.

The method of applying the coating liquid to the film can be a general coating method, such as Mayer bar coat, air knife coat, reverse roll coat, reverse gravure roll coat, gravure roll coat, lip coat, die coat, etc. The method is mentioned. Coating liquid application amount, 1 to 10 g / m ² is preferred. The drying conditions after coating are preferably 50 to 90 ° C. and 10 to 60 seconds. When the film is stretched after coating and drying, the stretching temperature is preferably 110 to 130 ° C., and the stretching ratio is preferably 3 to 4 times. Further, when heat treatment is performed after stretching, the heat treatment temperature is preferably 220 to 240 ° C. and the time is preferably 5 to 15 seconds.

  In addition, you may mix | blend additives, such as antioxidant and a lubricant, with the coating liquid and the polyester film of a base material in the range which cannot prevent the effect of this invention.

  Although the easy-adhesion polyester film of the present invention can be used as it is, surface treatment such as corona discharge or ion blow may be performed on the easy-adhesion surface or the non-adhesion-adhesive surface as a surface treatment.

  The easy-adhesion surface of the easy-adhesion polyester film of the present invention having the above-described configuration is excellent in adhesion to inks, adhesives, particularly photo-curing resins represented by hard coat agents, and these are laminated. Can be used.

  Although it does not prescribe | regulate especially as a photocurable resin provided in an easily bonding layer surface, an ultraviolet curable resin, especially an ultraviolet curable radical polymerization resin are desirable from the point of versatility and a handleability. Among them, the easily adhesive polyester film of the present invention is suitable as a base film for a hard coat layer made of an ultraviolet curable resin.

  Examples of the ultraviolet curable resin include urethane-acrylate, epoxy acrylate, and polyester-acrylate resins. In particular, in order for the hard coat layer resin itself to follow the expansion and contraction of the base material, an acrylate resin containing a urethane component as a soft segment is preferable.

  Furthermore, it is desirable to include inorganic fine particles in the photocurable resin in order to improve the abrasion resistance of the coating film and to reduce the volume shrinkage rate upon curing. Specific examples of the inorganic fine particles include fine particles made of a metal oxide such as silica or titanium. In addition, it is preferable that content of an inorganic fine particle is 20-60 mass% of the whole water-based adhesive. When the content of the inorganic fine particles is less than 20% by mass, the abrasion resistance is poor and the volumetric shrinkage during UV curing is high, and the film is curled. On the other hand, if it exceeds 60% by mass, the stretchability of the hard coat resin becomes poor, and cracking due to bending tends to occur. The average particle size of the inorganic fine particles is preferably 100 nm or less. When the average particle diameter exceeds 100 nm, the glossiness increases and the transparency may be further lowered. In order to improve hard coat properties, it is preferable to introduce a photosensitive group having photopolymerization reactivity onto the surface of the inorganic fine particles. Examples of the photosensitive group to be introduced include monofunctional or polyfunctional acrylates.

  Since the resin film using the water-based adhesive for forming an easy-adhesive layer of the present invention is excellent in easy adhesion, transparency, blocking resistance, and water resistance, it is easy to laminate another film. is there. The laminated body in which such a coating film is laminated | stacked can be used suitably for uses, such as the outermost layer film for liquid crystal displays, the outermost layer film of a touch panel, etc., for example.

Hereinafter, the present invention will be described specifically by way of examples.
The evaluation and measurement methods are as follows.

(1) Composition of polyester resin Using a high-resolution nuclear magnetic resonance apparatus (NMR manufactured by JEOL Ltd .; ECA-500 type), 1H-NMR analysis is performed to obtain a resin composition from the peak intensity of each copolymer component. (Resolution: 500 MHz, solvent: deuterated trifluoroacetic acid, temperature: 25 ° C.). In addition, for resins containing constituent monomers for which no peaks that can be attributed or quantified are observed on the 1H-NMR spectrum, they were subjected to methanol decomposition at 230 ° C. for 3 hours in a sealed tube, and then subjected to gas chromatogram analysis for quantitative analysis. I did it.

(2) Acid value of polyester resin 0.5 g of polyester resin is precisely weighed, dissolved in 50 ml of water / 1,4-dioxane = 1/9 (volume ratio) at room temperature, and 0.1N water using cresol red as an indicator. Titration with a potassium oxide methanol solution was carried out, and the number of mg of potassium hydroxide per 1 g of the polyester resin consumed for neutralization (mg KOH / g) was defined as the acid value.

(3) Glass transition temperature of polyester resin 10 mg of the polyester resin was weighed and increased using an input-compensated differential scanning calorimeter (DSC manufactured by Perkin Elmer; Diamond DSC type, detection range: −50 ° C. to 200 ° C.). Measurement is performed at a temperature rate of 10 ° C / min, and the slope of the curve of the step-like change portion of the glass transition is maximized in the temperature rise curve obtained by extending the low-temperature base line to the high-temperature side. The temperature at the intersection with the tangent drawn at such a point was determined and used as the glass transition temperature.

(4) Number average molecular weight, weight average molecular weight and dispersity of polyester resin The number average molecular weight and weight average molecular weight in terms of polystyrene were measured under the following conditions using gel permeation chromatography (GPC).
[Liquid feeding unit]: LC-10ADvp manufactured by Shimadzu Corporation
[Ultraviolet-visible spectrophotometer]: SPD-6AV manufactured by Shimadzu Corporation, detection wavelength: 254 nm
[Column]: One Shodex KF-803 and two Shodex KF-804s connected in series [Solvent]: Tetrahydrofuran [Measurement temperature]: 40 ° C.
From the above number average molecular weight (referred to as Mn) and weight average molecular weight (referred to as Mw), the degree of dispersion was determined by the following equation.
Dispersity = Mw / Mn

(5) Solid content concentration of aqueous dispersion or aqueous adhesive About 1 g of aqueous dispersion or aqueous adhesive was weighed (referred to as X ₁ g), and this was dried at 150 ° C. for 2 hours. The mass was weighed (Y ₁ g), and the solid content concentration was determined by the following formula.
Solid content concentration (% by mass) = (Y ₁ / X ₁ ) × 100

(6) Volume average particle diameter and number average particle diameter of aqueous dispersion or aqueous adhesive Dilute with water so that the solid concentration in the aqueous dispersion or aqueous adhesive is 0.1% by mass, and laser The volume average particle diameter and the number average particle diameter were measured using a diffractive particle diameter measuring apparatus (MICROTRAC UPA manufactured by Nikkiso Co., Ltd .; model 9340-UPA type). The refractive index of the polyester resin was set to 1.57, and the density of the polyester resin was set to 1.21 g / cm ³ .

(7) pH of aqueous dispersion or aqueous adhesive
Using a pH meter (F-21 type manufactured by HORIBA, Ltd.) and calibrating with a standard buffer solution of pH 7 and pH 9 (manufactured by Nacalai Tesque), the pH of the aqueous dispersion or aqueous adhesive is adjusted at a measurement temperature of 25 ° C. It was measured.

(8) Stability of aqueous dispersion or aqueous adhesive 30 g of aqueous dispersion or aqueous adhesive was collected, sealed in a 50 mL glass sample bottle, and stored at 25 ° C. for 90 days. After storage, the supernatant was collected from the sample bottle, the solid content concentration was measured, the ratio of the precipitate was calculated from the following formula, and the dispersion stability was evaluated.
Precipitate ratio (mass%) = {solid content concentration before storage (mass%) − solid content concentration after storage (mass%)} / {solid content concentration before storage (mass%)}
○: Less than 0.5% by mass Δ: Less than 1.0% by mass ×: 1.0% by mass or more, or the whole liquid is solidified and the supernatant cannot be collected.

(9) Film-forming property of resin coating A water-based adhesive is applied to a corona-treated surface of a biaxially stretched PET film (manufactured by Unitika Co., Ltd., thickness 50 μm) on a desktop coating apparatus (film applicator manufactured by Yasuda Seiki Co., Ltd .; No. 542). -AB type, equipped with a bar coater) and then dried for 2 minutes in a hot air dryer set at 100 ° C. to form a resin film having a thickness of 1 μm. This resin film was visually observed to evaluate the appearance.
In addition, the adhesive film (width: 18 mm) defined in JIS Z1522 is attached to the resin film except for one end, and the resin film formed as described above is rubbed with an eraser from the adhesive tape. After the adhesive film and the resin film were sufficiently bonded, the end of the adhesive tape was peeled off instantaneously after making the end of the adhesive tape perpendicular to the film. By analyzing the peeled adhesive tape surface with a surface infrared spectrometer (FT-IR manufactured by PerkinElmer, Inc .; using a SYSTEM2000 type, Ge60 ° 50 × 20 × 2 mm prism), a resin film adheres to the adhesive tape surface. It was classified according to whether or not the resin film was peeled off by the adhesive tape, and the adhesion was evaluated.
From the above two types of evaluation, the film forming property of the overall resin film was evaluated according to the following criteria.
The thickness of the resin film is measured in advance using a thickness meter (MICROFINE, manufactured by Union Tool Co., Ltd.). After the resin film is formed on the film using an aqueous dispersion, this resin film The thickness of the base material having a thickness was measured by the same method, and the difference was obtained.
○: Appearance defects such as cracks, fine irregularities, whitening, and peeling of the resin film with an adhesive tape are not observed.
X: Any of cracks, fine irregularities, appearance defects such as whitening, and peeling of the resin film with an adhesive tape are observed.

(10) Transparency of resin film After the same operation as (9) above was performed to form a resin film having a film thickness of 1 μm on a PET film, it was cut into a 50 mm × 50 mm test piece and a turbidimeter (Japan) The diffusion transmittance (Td) and the total light transmittance (Tt) were measured by a method according to JIS K7105 using Denshoku Industries Co., Ltd. (NDH2000 type), and Hz was calculated by the following formula. The calculated Hz was evaluated by comparing with the Hz of the base PET film alone. In addition, only the PET film of the base material, Hz was 4.2 (%).
Hz (%) = Td / Tt × 100
A: Hz was less than 4.2%, and the transparency of the substrate was not impaired.
X: Hz was 4.2% or more, and the transparency of the substrate was impaired.

(11) Water resistance of resin film The same operation as (9) was performed to form a resin film having a thickness of 1 µm on the PET film. The PET film on which the obtained resin film was formed was
(1) It was immersed in distilled water at 25 ° C., gently pulled up after 24 hours and air-dried, and then the appearance of the resin film was visually observed.
(2) It was immersed in boiling water at about 100 ° C., gently pulled up after 1 hour and air-dried, and then the appearance of the resin film was visually observed.
Evaluation methods were evaluated according to the following criteria.
A: No change in appearance.
Δ: Although a part of the appearance was changed (the surface became cloudy white, etc.), the resin film did not dissolve or swell.
X: The resin film was dissolved or swollen.

(12) Blocking resistance of resin film In the same manner as in (9) above, after forming a resin film having a film thickness of 1 μm on a PET film, a load of 500 Pa with another PET film superimposed on the film formation surface After standing for 24 hours in an atmosphere of 38 ° C. and cooling to 25 ° C., the two PET films are peeled off by hand and classified as follows according to whether they can be easily peeled off, and are resistant to blocking. Sex was evaluated.
○: Can be easily peeled off, and no fusion mark is observed.
X: There is considerable resistance when peeling, and a fusion mark is recognized.

(13) Resin film easy adhesion In the same manner as in (9) above, a resin film having a thickness of 1 μm was formed on a PET film. An acrylic hard coat resin (Seika Beam PHC, manufactured by Dainichi Seika Co., Ltd.) was similarly applied onto the resin film using a desktop coating apparatus, and a low-pressure mercury lamp UV cure apparatus (manufactured by Toshiba Lighting & Technology Corp., 40 mW / cm, one lamp) Curing was performed according to the formula (1) to form a hard coat layer having a thickness of 3 μm. The adhesion of this coating film was confirmed by a cross-cut method in accordance with JIS K-5600-5-6. “100/100” is the best state with no peeling, and “0/100” is the best state with all peeling. 100/100 to 80/100 is acceptable, 100/100 to 90/100 is more excellent, and 100/100 is the most excellent.

(14) Ease of resin coating In the same manner as in (9) above, a resin coating having a thickness of 1 μm was formed on a PET film. According to ASTM D-1894, the dynamic friction coefficient (μk) of the resin film surface was measured with an autograph manufactured by Shimadzu Corporation. μk is preferably less than 0.5.

[Preparation of polyester resin]
By the following procedure, polyester resins (a1) to (a10) used in Examples and Comparative Examples were obtained.

Preparation Example 1
A mixture comprising 1911 g of terephthalic acid, 1911 g of isophthalic acid, 292 g of adipic acid, 1024 g of ethylene glycol, and 1666 g of neopentyl glycol was heated in an autoclave at 250 ° C. for 4 hours to carry out an esterification reaction. At this time, the monomer components were blended with terephthalic acid: isophthalic acid: adipic acid: ethylene glycol: neopentyl glycol = 46: 46: 8: 66: 64 (molar ratio). Subsequently, after adding 3.3 g of zinc acetate dihydrate as a catalyst (6.0 × 10 −4 mol per 1 mol in total of all acid components), the temperature of the system was raised to 260 ° C. Was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was continued, and after 4 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when it reached 250 ° C., 26 g of trimellitic acid (0 per mole of total acid components in total) 0.006 mol) was added and the mixture was stirred at 250 ° C. for 2 hours to carry out a depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a strand shape. After cooling with water, cutting was performed to obtain a pellet-shaped polyester resin (a1) having a diameter of about 3 mm and a length of about 3 mm.

Preparation Examples 2 to 10
Polyester resins (a2) to (a10) were obtained in the same manner as the polyester resin (a1) except that the charging composition was changed as shown in Table 1. Polyester resins (a2) to (a4) and (a7) to (a9) are discharged into a sheet, and, except for (a7), after sufficiently cooling to room temperature, they are crushed with a crusher and sieved. A fraction having an opening of 1 to 6 mm was collected by using to obtain a granular polyester resin.

In Table 1, abbreviations indicate the following.
TPA: terephthalic acid IPA: isophthalic acid ADA: adipic acid SEA: sebacic acid SIPA: 5-sodium sulfoisophthalic acid EG: ethylene glycol NPG: neopentyl glycol 1,2-PD: 1,2-propanediol BAEO: 2, 2 -Ethylene oxide adduct of bis [4- (hydroxyethoxy) phenyl] propane TMA: trimellitic acid

  Table 2 shows the final resin compositions and characteristic values of the obtained polyester resins (a1) to (a10).

[Preparation of aqueous dispersion of polyester resin]
Polyester resin aqueous dispersions (A-1) to (A-10) were obtained by the following procedure. Various evaluation was performed about the obtained polyester resin aqueous dispersion (A-1)-(A-10).

Preparation Example 11
[Dissolution process]
400 g of polyester resin (a1) and 600 g of methyl ethyl ketone are put into a 2 L polyethylene container, and the mixture is heated and stirred so that the temperature inside the system becomes 50 ° C., and the polyester resin (a1) is completely dissolved in methyl ethyl ketone to obtain a solid content concentration. A 40 mass% polyester resin (a1) solution was obtained.
[Phase inversion emulsification process]
500 g of the polyester resin (a1) solution is charged into a glass container (2 L content) and stirred while maintaining the system temperature at 22 ° C., and 23 g of triethylamine as a basic compound (based on the acid value of the polyester resin (a1)) 15 times equivalent). Subsequently, 542 g of 17 ° C. ion-exchanged water was added at a rate of 40 g / min, and then stirring was continued for 30 minutes. The system temperature during addition of the entire amount of distilled water was 17 ± 1 ° C., and the solid content concentration after the addition of distilled water was 20% by mass.
[Desolvation process]
800 g of the obtained polyester resin (a1) dispersion was charged into a round bottom flask, a mechanical stirrer and a Liebig condenser were installed, the flask was heated in an oil bath, and 315 g of an aqueous medium was distilled off at normal pressure. Thereafter, the mixture is cooled to room temperature, and further stirred, 0.4 g of 28% by mass aqueous ammonia is added. Finally, ion-exchanged water is added so that the solid content concentration becomes 30% by mass. A-1) was obtained. The evaluation results are shown in Table 3.

Preparation Example 12
Prepared except that the polyester resin (a2) is used, the triethylamine used in the phase inversion emulsification step is 14 g (6 times equivalent to the acid value of the polyester resin (a2)), and the ion-exchanged water is 551 g. The same adjustment as in Example 10 was performed to obtain an aqueous polyester resin dispersion (A-2). The evaluation results are shown in Table 3.

Preparation Example 13
Using a jacketed cylindrical glass container (with an internal volume of 3 L) and a stirrer (manufactured by Tokyo Science Instruments Co., Ltd., “MAZELA NZ-1200”), 300 g of polyester resin (a3), 180 g of isopropanol, triethylamine 9.5 g (corresponding to 1.2 times equivalent of triethylamine with respect to the acid value of the polyester resin) and 510 g of distilled water were each placed in a glass container, and the jacket was stirred while stirring at a rotational speed of 70 rpm. The temperature was raised through hot water. When the internal temperature reached 70 ° C., the temperature was raised and stirring was continued for 120 minutes. During stirring, the internal temperature was kept at 72 ± 2 ° C. Thereafter, cold water was passed through the jacket, and the rotation speed was lowered to 30 rpm and the mixture was cooled to 25 ° C. while stirring to obtain an aqueous polyester resin dispersion. The obtained aqueous dispersion was filtered with a 600 mesh stainless steel filter to obtain an aqueous polyester resin dispersion (A-3). The evaluation results are shown in Table 3.

Preparation Example 14
Except having used a polyester resin (a4), preparation similar to the preparation example 13 was performed, and the polyester resin aqueous dispersion (A-4) was obtained. The evaluation results are shown in Table 3.

Preparation Example 15
Except having used a polyester resin (a5), preparation similar to the preparation example 13 was performed, and the polyester resin aqueous dispersion (A-5) was obtained. The evaluation results are shown in Table 3.

Preparation Example 16
Preparation except that the polyester resin (a6) is used, the triethylamine used in the phase inversion emulsification step is 18 g (6 times equivalent to the acid value of the polyester resin (a6)), and the ion-exchanged water is 548 g. The same preparation as in Example 11 was performed to obtain an aqueous polyester resin dispersion (A-6). The evaluation results are shown in Table 3.

Preparation Example 17
Prepared except that the polyester resin (a7) is used, the triethylamine used in the phase inversion emulsification step is 12 g (6 times equivalent to the acid value of the polyester resin (a7)), and the ion-exchanged water is 553 g. The same preparation as in Example 11 was performed to obtain an aqueous polyester resin dispersion (A-7). The evaluation results are shown in Table 3.

Preparation Example 18
A polyester resin aqueous dispersion (A-8) was obtained in the same manner as in Preparation Example 13, except that the polyester resin (a8) was used. The evaluation results are shown in Table 3.

Preparation Example 19
Except having used a polyester resin (a9), preparation similar to the preparation example 13 was performed, and the polyester resin aqueous dispersion (A-9) was obtained. The evaluation results are shown in Table 3.

Preparation Example 20
Except for using the polyester resin (a10), the same adjustment as in Preparation Example 11 was performed, but the polyester resin aggregated during the phase inversion emulsification step, and the stable polyester resin aqueous dispersion using (a10) was used. I couldn't get a body.

Preparation Example 21
To the polyester resin (a10) used in Preparation Example 20, 50 g of a 10 g aqueous solution of 25 g of a surfactant (“Igepal CO720” manufactured by Aldrich) was added in the phase inversion emulsification step. Then, adjustment similar to the preparation example 11 was performed, and the polyester resin dispersion (A-10) was obtained. The evaluation results are shown in Table 3.

Example 1
Various characteristics of the resin coating obtained using the aqueous polyester resin dispersion (A-1) were evaluated. The results are shown in Table 4.

Examples 2-5 and Comparative Examples 1-5
The polyester resin aqueous dispersion was changed as shown in Table 4, and various properties were evaluated in the same manner as in Example 1. The results are shown in Table 4.

Adjustment example 22
(Production of aqueous polyurethane resin dispersion B-1)
A reactor equipped with a stirrer, thermometer, nitrogen seal tube, and condenser is charged with 345 parts by mass of polytetramethylene glycol having an average molecular weight of 1970, 77.8 parts by mass of isophorone diisocyanate, and 0.03 parts by mass of dibutyltin dilaurate. And reacted at 80 ° C. for 2 hours. Subsequently, after cooling this reaction liquid to 50 degreeC, 11.7 mass parts of dimethylpropanolamine, 8.85 mass parts of triethylamine, and 177 mass parts of acetone were added, and it was made to react. Further, 175 parts by mass of acetone was added to the reaction liquid and cooled to 30 ° C., 13.4 parts by mass of isophorone diisocyanate, 1.07 parts by mass of monoethanolamine, 87.9 parts by mass of isopropyl alcohol, and 1039 parts by mass of water. A mixed liquid consisting of parts was added and stirred at a high speed, and acetone and IPA were distilled off from this liquid to obtain a polyether type polyurethane resin aqueous dispersion (solid content concentration 30% by mass) B-1.

(Polyester type polyurethane resin aqueous dispersion B-2)
As the polyurethane resin aqueous dispersion, “Adeka Bon titer UX-0666” (solid content concentration: 40% by mass) manufactured by Adeka Company was used.

[Example 6]
Mass ratio of the polyester resin (a1) contained in the polyester resin dispersion (A-1), the polyurethane resin (b1) contained in the polyurethane resin aqueous dispersion (B-1), and the silica particles (c1) (hereinafter, solid content) 228.7 parts by mass of the polyester resin dispersion (A-1) and the aqueous polyurethane resin dispersion (B-) so that the mass ratio is (a1) / (b1) / (c1) = 70/30/2 1) 98.0 parts by mass and 10.0 parts by mass of a 20% by mass aqueous dispersion (C-1) of silica particles (c1) were mixed and stirred to obtain an aqueous adhesive (S-1). Various characteristics were evaluated. The results are shown in Table 5.

In Table 5, abbreviations indicate the following.
Silica particle (c1): Mizusukacil P-50 manufactured by Mizusawa Chemical Industry (oil absorption 170 ml / 100 g, bulk specific gravity 0.32, average particle size: 10 μm)
Silica particles (c2): Mizusukacil P-527 manufactured by Mizusawa Chemical Industry (oil absorption 130 ml / 100 g, bulk specific gravity 0.19, average particle size 2 μm)
Silica particles (c3): Mizukasil P-78D manufactured by Mizusawa Chemical Industry (oil absorption 240 ml / 100 g, bulk specific gravity 0.24, average particle size 12 μm)

Examples 7-16
Table 5 shows the types of the aqueous polyester resin dispersion, the aqueous polyurethane resin dispersion, the 20% by mass aqueous dispersion of silica particles, and the solid content mass ratio {(a) / (b) / (c)}. Except having changed into, it carried out similarly to Example 6, obtained aqueous dispersion (S-2)-(S-11), and evaluated various characteristics. The results are shown in Table 5.

Example 17
The biaxially stretched PET film (S-1) was used in the same manner as in the above (9) Evaluation of the film-forming property of the resin film except that the conditions of the desktop coating apparatus were changed using the aqueous adhesive (S-1). A resin film having a thickness of 0.05 μm was formed on a corona-treated surface (product of Unitika, thickness 50 μm), and various characteristics were evaluated. The results are shown in Table 5. The evaluation method of the resin film having a film thickness of 0.05 μm was performed in the same manner as in the case of the film thickness of 1 μm.

Example 18
The biaxially stretched PET film (S-1) was used in the same manner as in the above (9) Evaluation of the film-forming property of the resin film except that the conditions of the desktop coating apparatus were changed using the aqueous adhesive (S-1). A resin film having a film thickness of 0.1 μm was formed on a corona-treated surface manufactured by Unitika Ltd. (thickness 50 μm), and various properties were evaluated. The results are shown in Table 5. The evaluation method of the resin film having a film thickness of 0.1 μm was performed in the same manner as in the case of the film thickness of 1 μm.

Example 19
First, an aqueous adhesive (S-1) was prepared. An unstretched PET film having a thickness of 260 μm was stretched three times in the machine direction at 90 ° C., and then the aqueous adhesive (S-1) was applied (coated) with a bar coater. Next, after drying at 65 ° C., the film was stretched 4.0 times in the transverse direction at 120 ° C., and then heat-treated at 230 ° C. for 5 seconds. The 25 μm-thick PET film thus obtained by successive stretching formed a resin film having a thickness of 0.2 μm. Thereafter, various characteristics were evaluated. The results are shown in Table 5. The evaluation method of the resin film having a film thickness of 0.2 μm was performed in the same manner as in the case of the film thickness of 1 μm.

  Since Examples 1-19 followed a predetermined composition, the obtained water-based adhesive had good stability, and the resin film obtained from the water-based adhesive was excellent in easy adhesion, transparency, blocking resistance, and water resistance. A film was formed. In particular, in Examples 6 to 10 and 19, since the polyester resin (A), the polyurethane resin (B), and the silica particles (C) were respectively used in specific formulations, the resin film obtained from the aqueous adhesive was easily bonded. In addition to water resistance, transparency, blocking resistance, and water resistance, it was possible to form a film having hot water resistance and slipperiness and superior adhesion.

  In Comparative Example 1, since the dicarboxylic acid component of the polyester resin (A) contained 1 mol% or more of dicarboxylic acid having a sulfonate group, the resulting resin film was inferior in water resistance.

  Since the glass transition temperature was less than 40 degreeC in the comparative example 2, the obtained resin film was inferior to blocking resistance.

  In Comparative Example 3, since the glass transition temperature exceeded 75 ° C., the obtained resin film was inferior in easy adhesion.

  In Comparative Example 4, since the number average molecular weight was less than 5000, the obtained resin film was inferior in adhesion.

In Comparative Example 5, since a surfactant was used as a raw material for the aqueous polyester resin dispersion, the resulting resin film had poor water resistance.

Claims (9)

  A polyester resin (A) mainly composed of a dicarboxylic acid component and a glycol component, an aqueous adhesive for forming an easy adhesion layer containing a basic compound and water and substantially not containing an emulsifier, the polyester resin (A ) Has an acid value of 4 mgKOH / g or more, a glass transition temperature of 40 to 75 ° C., a number average molecular weight of 5,000 to 50,000, and a dicarboxylic acid component constituting the polyester resin (A), the content of a dicarboxylic acid having a sulfonate group Is an aqueous adhesive for forming an easy-adhesion layer, characterized by being less than 1 mol%.   Furthermore, it contains a polyurethane resin (B), and contains a polyester resin (A) and a polyurethane resin (B) in a ratio of (A) / (B) = 99/1 to 40/60 (mass ratio). The water-based adhesive for forming an easy adhesion layer according to claim 1.   The water-based adhesive for forming an easily adhesive layer according to claim 2, wherein the polyurethane resin (B) is a polyether type polyurethane resin.   The water-based adhesive for forming an easily adhesive layer according to claim 3, wherein the polyether polyol component of the polyether type polyurethane resin is polytetramethylene glycol.   The aqueous adhesive for forming an easy adhesion layer according to claim 3 or 4, wherein the isocyanate component of the polyether type polyurethane resin is isophorone diisocyanate.   Furthermore, inorganic particle (C) is contained, The water-based adhesive for easily bonding layer formation in any one of Claims 1-5 characterized by the above-mentioned.   An easy-adhesion film formed by removing an aqueous medium from the aqueous adhesive for forming an easy-adhesion layer according to claim 1.   A laminate obtained by forming the easy-adhesion film according to claim 7 on a substrate. The laminate according to claim 8, wherein an acrylic coating is further provided on the coating.