JP2015086248A - Aqueous adhesive agent and coated film obtained from the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous adhesive agent excellent in adhesiveness with especially an acrylic coat layer, and also excellent in transparency, blocking resistance and water resistance, and capable of forming an easy adhesive coated film.SOLUTION: There is provided an aqueous adhesive agent containing (A) a polyester resin constituted mainly by a dicarboxylic acid component and a glycol component, a basic compound and water and substantially containing no emulsifier, where the polyester resin (A) contains a compound represented by the general formula (I) of 50 to 100 mol% as the glycol component and has the acidic value of 4 mgKOH/g or more, a glass transition temperature of 40°C or more and a number average molecular weight of 5000 to 50000. In the formula (I), Xand Xare a hydroxy alkylene group having 1 to 4 carbon atoms and/or a group in which alkylene oxide of 1 to 4 mol is added to the hydroxy alkylene group having 1 to 4 carbon atoms and may be the same or different.

Description

  The present invention relates to an easily adhesive layer-forming water-based adhesive capable of forming an easily adhesive film excellent in transparency, blocking resistance and water resistance.

  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

The present inventors have found the following.
That is, in a normal polyester resin aqueous dispersion, for example, in a polyester resin aqueous dispersion in which aqueous dispersion is performed using a hydrophilic component such as 5-sodium sulfoisophthalic acid, the hydrophilic component should remain significantly. In particular, a decrease in adhesiveness with the acrylic coat layer became a problem.
However, in the specific polyester resin aqueous dispersion as in the present invention, not only the adhesion with the acrylic coating layer is improved, but also a specific amount of a dicarboxylic acid component having a sulfonic acid group such as 5-sulfoisophthalic acid is introduced. By doing so, it discovered that adhesiveness with an acrylic-type coating layer improved effectively.

  An object of the present invention is to provide an aqueous adhesive that is particularly excellent in adhesiveness with an acrylic coating layer and that can form an easy-adhesive film excellent in transparency, blocking resistance, and water resistance.

  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, an aqueous adhesive containing a basic compound and water, and substantially free of an emulsifier, wherein the polyester resin (A) is The glycol component contains 50 to 100 mol% of a compound represented by the following general formula (I), has an acid value of 4 mgKOH / g or more, a glass transition temperature of 40 ° C. or more, and a number average molecular weight of 5,000 to 50,000. Water-based adhesive.
(X ₁ and X ₂ are groups having 1 to 4 moles of alkylene oxide added to a hydroxyalkylene group having 1 to 4 carbon atoms and / or a hydroxyalkylene group having 1 to 4 carbon atoms. Also good)
(2) The aqueous adhesive according to (1), wherein 1 to 10 mol% of dicarboxylic acid having a sulfonate group is contained with respect to 100 mol% of the dicarboxylic acid component constituting the polyester resin (A).
(3) The aqueous adhesive according to (1) or (2), further comprising 1 to 10 parts by mass of the curing agent (B) with respect to 100 parts by mass of the nonvolatile component of the aqueous adhesive.
(4) The aqueous adhesive according to (1) to (3), further comprising inorganic particles (C).
(5) A film formed by removing an aqueous medium from the aqueous adhesives of (1) to (4).
(6) A laminate obtained by forming the film of (5) on a substrate.
(7) The laminate of (6), 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 easily bonding layer formation of the present invention contains at least a polyester resin (A), and may contain a curing agent (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.

As the acid component constituting the polyester resin (A), any one can be used, but the glycol component contains 50 to 100 mol% of the compound represented by the general formula (I), and the acid value is 4 mgKOH / g. As described above, it is necessary that the glass transition temperature is 40 ° C. or higher and the number average molecular weight is 5000 to 50000.
(X ₁ and X ₂ are groups having 1 to 4 moles of alkylene oxide added to a hydroxyalkylene group having 1 to 4 carbon atoms and / or a hydroxyalkylene group having 1 to 4 carbon atoms. Also good)

Examples of the compound represented by the general formula (1) include tricyclo [5.2.1.0 ^2,6 ] decanedimethanol, 4,10-dimethyltricyclo [5.2.1.0 ^2,6 ] dedecane. Candimethanol, 4,4,10,10-tetramethyltricyclo [5.2.1.0 ^2,6 ] decanedimethanol, 1,2,3,4,5,6,7,8,9,10 -Decamethyltricyclo [5.2.1.0 ^2,6 ] decanedimethanol. Among them, tricyclo [5.2.1.0 ^2,6 ] decandi is highly versatile and has a high effect of improving the adhesion with an acrylic coating film from the resulting aqueous adhesive. Methanol is preferred.

  In 100 mol% of the glycol component constituting the polyester resin (A), the compound represented by the general formula (1) is 50 to 100 mol%, preferably 55 to 95 mol%, preferably 60 to 90 mol%. More preferably. When the content of the compound represented by the general formula (1) is less than 50 mol%, the film formed from the obtained aqueous adhesive has poor adhesion to the acrylic film.

  Examples of the glycol component that can be used in combination with the compound represented by formula (I) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, and 2-methyl-1 , 3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropane Aliphatic glycols such as diols, alicyclic glycols such as 1,4-cyclohexanedimethanol and 1,3-cyclobutanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, etc. Of ether bond containing Call, 2,2-bis [4- (hydroxyethoxy) phenyl] alkylene oxide adducts of propane, bis [4- (hydroxyethoxy) phenyl] sulfone of the alkylene oxide adducts thereof. Among these, ethylene glycol, neopentyl glycol, and 1,2-propanediol are preferable from the viewpoint of versatility, polymerizability, and resin properties.

  Examples of the acid component constituting the polyester resin (A) include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 3-tert-butylisophthalic acid, and diphenic acid. Saturated aliphatic dicarboxylic acids such as acid, oxalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosandioic acid, hydrogenated dimer acid, fumaric acid, maleic acid, maleic anhydride Unsaturated fatty dicarboxylic acids such as itaconic acid, 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 include alicyclic dicarboxylic acids such as their anhydrides, among others, are preferably used in combination with aromatic dicarboxylic acids, saturated aliphatic 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.

  When an aromatic dicarboxylic acid and a saturated aliphatic dicarboxylic acid are used in combination, 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 / It is preferably 30 to 95/5 (molar ratio), more preferably 73/27 to 93/7 (molar ratio), and even more preferably 75/25 to 90/10 (molar ratio). .

When aromatic dicarboxylic acid and saturated aliphatic dicarboxylic acid are used in combination, as the aromatic dicarboxylic acid, terephthalic acid and isophthalic acid can be preferably used, and in particular, terephthalic acid can be used alone. In order to enhance the solvent solubility of the resin, terephthalic acid and isophthalic acid can be mixed and used. The mixing ratio of terephthalic acid and isophthalic acid is preferably 95/5 to 55/45 (molar ratio), and more preferably 75/25 to 60/40 (molar ratio).
Further, as the saturated aliphatic dicarboxylic acid, adipic acid and sebacic acid can be preferably used, and sebacic acid is more preferable because the effect of improving the alcohol resistance of the obtained polyester resin is particularly high. The improvement in alcohol resistance means that the durability of the coating film obtained using a water-based adhesive is increased, and at the same time, for example, when an acrylic coating film or the like is formed on the coating film, adhesion or adhesion is improved. It is particularly preferable because durability such as property is increased.

Moreover, you may contain the dicarboxylic acid which has a sulfonate group as an acid component which comprises a polyester resin (A) as needed. When the dicarboxylic acid having a sulfonate group is contained, the content thereof is preferably 1 to 10 mol%, and 2 to 8 mol% in 100 mol% of the acid component constituting the polyester resin (A). More preferably, it is 3-6 mol. By containing the dicarboxylic acid which has a sulfonate group, there exists a tendency for the adhesiveness of the film formed from the aqueous adhesive obtained with an acrylic coating film to improve. In addition, when using the dicarboxylic acid which has a sulfonate group in 10 mol% or more in 100 mol% of acid components which comprise a polyester resin (A), the water resistance of the film formed from the aqueous adhesive obtained is impaired significantly. Sometimes. 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.
As described above, when an aromatic dicarboxylic acid and a saturated aliphatic dicarboxylic acid are used in combination, and a dicarboxylic acid having a sulfonate group is further used, the water resistance of the coating is reduced due to the inclusion of the dicarboxylic acid having a sulfonate group. Even if it is a case, since there exists a tendency which suppresses the said water-resistant fall by the combined use effect of aromatic dicarboxylic acid and saturated aliphatic dicarboxylic acid, it is especially preferable to set it as such a composition.

  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 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 (A) 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 (A) 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 a tri- or higher functional carboxylic acid or a tri- or higher functional alcohol is charged before the esterification reaction and the polycondensation reaction proceeds, the resulting polyester resin (A) has a wide dispersion or gelled. Since polymerization may not be possible, the content thereof is preferably 0 to 1 mol%, and 0 to 0.8 mol%, with respect to 100 mol% of the dicarboxylic acid component and the glycol component, respectively. 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 (A) used in the present invention is required to be 4 mgKOH / g or more and is 4 to 40 mgKOH / g in order to improve the stability of the water-based adhesive for easily bonding layer formation. Is preferable, and it is more preferable that it is 4-20 mgKOH / g. When the acid value of the polyester resin (A) 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-based adhesive for forming an easily adhesive layer is poor. This is not preferable.

  The glass transition temperature of the polyester resin (A) used in the present invention needs to be 40 ° C. or higher, preferably 60 ° C. or higher, and more preferably 80 ° C. or higher. By setting the glass transition temperature to 80 ° C., the resin film obtained from the water-based adhesive for forming an easy adhesion layer is excellent in blocking resistance and easy adhesion. When the glass transition temperature of the polyester resin (A) is less than 40 ° C., the resin film obtained from the water-based adhesive for easily bonding layer formation is inferior in blocking resistance.

  The number average molecular weight of the polyester resin (A) used in the present invention is required to be 5000 to 50000, and preferably 5000 to 30000 in order to improve the film forming property and adhesiveness of the resulting resin film. 7000-30000, more preferably 9000-25000. When the number average molecular weight of the polyester resin (A) is less than 5,000, 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 degree of dispersion in the molecular weight distribution of the polyester resin (A) used in the present invention (hereinafter sometimes abbreviated as “dispersion degree”) is preferably 2 to 10, more preferably 2 to 9. Preferably, it is 2-8. 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. In addition, it is difficult to design the polyester resin (A) having a dispersity of less than 2 itself.

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

  The polyester resin (A) 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., 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 in which the polyester resin (A) is dispersed 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. . Such an emulsifier preferably has a zero content, but may be contained in an amount of less than 0.1 parts by mass with respect to 100 parts by mass of the polyester resin (A) 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 (A) can be easily dispersed in an aqueous medium. On the other hand, such blending 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 polyester resin aqueous dispersion of the present invention, the content of the polyester resin (A) is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, and 15 to 40% by mass. More preferably. By setting the content of the polyester resin (A) to 5 to 50% by mass, handling properties are improved. Further, since the dispersed polyester resin (A) 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 (A) 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 (A) fine particles is preferably less than 200 nm, more preferably less than 150 nm, still more preferably less than 100 nm, and 50 nm. Most preferably, it is less than. By making the volume average particle diameter less than 200 nm, the dispersed polyester resin (A) 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 polyester resin (A) is dispersed in an aqueous medium by neutralizing at least partly or entirely using a basic compound. Is done. By neutralizing the carboxyl group, a carboxyl anion is generated, and the dispersed polyester resin (A) 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 containing an organic solvent by dissolving the polyester resin (A) in an organic solvent (dissolution step), adding a basic compound and water to the polyester resin solution (phase inversion emulsification step). This is a method for obtaining an aqueous dispersion, and can be suitably used for a wider range of polyester resin (A). In addition, the self-emulsification method is a method in which a polyester resin (A), a basic compound, an organic solvent, and water are charged together and heated while stirring in the system to obtain an aqueous polyester resin dispersion containing an organic solvent. It is a method and 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 the organic solvent contained in the organic solvent liquid of the polyester resin (A) to the organic solvent liquid system. To an O / W emulsion dispersion.

  In the dissolving step, the polyester resin (A) is dissolved in an organic solvent to obtain an organic solvent solution of the polyester resin (A). If the polyester resin (A) 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 (A) is dispersed in an aqueous medium together with a 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 setting the charging speed of the aqueous medium to 25 to 100 parts by mass / min, it is possible to uniformly disperse the polyester resin (A) while suppressing the formation of the lump.

  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 (A) 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 (A) in the dissolution step, the concentration of the polyester resin (A) in the resulting solution is preferably 10 to 70% by mass, and 20 to 60% by mass. More preferably, it is more preferable to set it as 30-50 mass%. By setting the concentration of the polyester resin (A) in the solution to 10 to 70% by mass, an increase in viscosity when mixed with water in the next phase inversion emulsification step is suppressed, so the volume average particle size of the aqueous dispersion It can suppress that a diameter becomes large.

  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 (boiling point: −33 ° C.), ethylamine, diethylamine, dibutylamine, triethylamine (boiling point: 90 ° C.), propylamine, isopropylamine, iminobispropylamine, 3-ethoxy. Propylamine, 3-diethylaminopropylamine, diethanolamine (boiling point: 217 ° C), triethanolamine (boiling point: 360 ° C), N, N-diethylethanolamine (boiling point: 163 ° C), N, N-dimethylethanolamine (boiling point) : 133 ° C.), and organic amines such as aminoethanolamine, morpholine, N-methylmorpholine, 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 preferred because it can suppress the hydrolysis reaction of the polyester resin (A) 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 (boiling point: −33 ° C.), triethylamine (boiling point: 90 ° C.), and N, N-dimethylethanolamine (boiling point: 133 ° C.).

  The basic compound is preferably added in an amount of 0.5 to 30 times equivalent, more preferably 0.8 to 25 times equivalent, and more preferably 1 to 20 times equivalent to the acid value of the polyester resin (A) to be used. More preferably, it is added. By adding the basic compound in an amount of 0.5 to 30 times the acid value of the polyester resin (A), 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 solvent removal step, the organic solvent contained is preferably reduced as much as possible in the solvent removal.

  As the basic compound used in the production of the aqueous polyester resin dispersion, for example, when a basic compound having a boiling point of less than 100 ° C. such as ammonia (boiling point: −33 ° C.) or triethylamine (boiling point: 90 ° C.) is used, In the solvent removal step, the basic compound can be easily removed together with the organic solvent. On the other hand, the storage stability of the aqueous polyester resin dispersion can be improved by making the obtained aqueous polyester resin dispersion higher than pH = 7 and slightly tilting toward the basic side. That is, it is particularly preferable to increase the storage stability of the aqueous polyester resin dispersion by reducing the organic solvent as much as possible and leaving the basic compound slightly after the solvent removal step. In order to achieve such a state, the second basic compound having a boiling point higher than that of the first basic compound used in the production of the polyester resin aqueous dispersion before or during the solvent removal step is used. After the solvent removal step is completed, the organic solvent is reduced as much as possible, and among the basic compounds, the second basic compound remains, in particular, the pH is higher than 7, and the polyester resin aqueous dispersion The storage stability of the body can be increased. As such a combination of basic compounds, for example, when ammonia (boiling point: −33 ° C.) or triethylamine (boiling point: 90 ° C.) is used as the first basic compound, as the second basic compound, N, N-diethylethanolamine (boiling point: 163 ° C.) and N, N-dimethylethanolamine (boiling point: 133 ° C.) can be suitably used.

  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 curing agent (B) in order to improve easy-adhesion.

  Examples of the curing agent (B) that can be used in the present invention include amino resins such as urea resins, melamine resins, and benzoguanamine resins, polyfunctional epoxy compounds, polyfunctional isocyanate compounds, and various blocked isocyanate compounds, polyfunctional aziridine compounds. Carbodiimide group-containing compound, oxazoline group-containing polymer, 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 easy-adhesion property and solvent resistance.

  When using a hardening | curing agent (B) for the water-based adhesive for easily bonding layer formation of this invention, it is preferable from the surface of a working environment to use as an aqueous dispersion of a hardening | curing agent (B). Further, the aqueous dispersion of the polyester resin (A) and the aqueous dispersion of the curing agent (B) can be easily mixed, and in order to obtain a uniform aqueous adhesive for forming an easily adhesive layer, the curing agent (B ) Aqueous dispersion can be suitably used.

  There is no restriction | limiting in particular in the manufacturing method of the aqueous dispersion of a hardening | curing agent (B), What is necessary is just to use a general method. For example, in the case of a 100 wt% curing agent capable of being dispersed in water, a dispersion can be produced by stirring to the same amount or more of water using a homomixer. What is necessary is just to use as it is in the case of the hardening | curing agent of a commercially available aqueous dispersion.

  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.

  Although it does not specifically limit as a method to obtain the water-based adhesive for easily bonding layer formation of this invention, For example, (1) Aqueous dispersion of polyester resin (A), Aqueous dispersion of hardening | curing agent (B), inorganic particle ( C) A method of mixing and stirring an aqueous dispersion of (2) After mixing the polyester resin (A) and the curing agent (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.

  In the water-based adhesive for forming an easy-adhesion layer of the present invention, the polyester resin (A) and the curing agent (B) are blended in such a way that the nonvolatile component of the water-based adhesive of the present invention is 100 parts by weight of the curing agent (B) Is preferably 1 to 10 parts by mass, more preferably 1 to 8 parts by mass, and still more preferably 1 to 5 parts by mass. When it is within the above range, the resin film obtained is more excellent in easy adhesion, water resistance and solvent resistance.

  Further, 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 curing agent (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 leveling agents, antifoaming agents, other thickeners, color pigments, water, and alcohol.

  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-naphthalenedicarboxylate, and the like. Also included are blends of

  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. The coating liquid application amount is preferably 1 to 10 g / m ² . The drying conditions after coating are preferably 50 to 120 ° C. and 10 to 500 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 does not prevent the effect of this invention as needed.

  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 typified 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) Configuration of polyester resin Using a high resolution nuclear magnetic resonance apparatus (NMR manufactured by JEOL Ltd .; ECA-500 type), ¹ H-NMR analysis is performed to determine the resin composition from the peak intensity of each copolymer component. (Resolution: 500 MHz, solvent: deuterated trifluoroacetic acid, temperature: 25 ° C.). In addition, with respect to a resin containing a constituent monomer in which no assignable / quantifiable peak is observed on the ¹ H-NMR spectrum, it is subjected to methanol decomposition at 230 ° C. for 3 hours in a sealed tube, followed by 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 .; -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
(I) 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.
(Ii) 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. It is assumed that those with O to ΔΔ can withstand practical use.
○: No change in appearance.
Δ: Part of the resin coating was whitened.
ΔΔ: A part of the resin film swelled.
X: The entire resin film was dissolved or swollen.

(12) Alcohol 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
(I) After being immersed in isopropanol at 25 ° C., gently pulled up after 24 hours and air-dried, the appearance of the resin coating was visually observed.
(Ii) It was immersed in isopropanol at about 50 ° C., gently pulled up after 1 hour and air-dried, and then the appearance of the resin coating was visually observed.
Evaluation methods were evaluated according to the following criteria.
○: No change in appearance.
Δ: Part of the resin coating was whitened or swollen.
X: The entire resin film was dissolved or swollen.

(13) Blocking resistance of resin coating In the same manner as in (9) above, after forming a resin coating with a thickness of 1 μm on a PET film, a load of 500 Pa with another PET film superimposed on the coating 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.

(14) Easy adhesion 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. 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.

(15) Ease of resin coating In the same manner as in (9), 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 consisting of 2990 g of terephthalic acid, 1262 g of ethylene glycol and 2619 g of tricyclo [5.2.1.0 (2,6)] decanedimethanol was heated at 250 ° C. for 4 hours in an autoclave to carry out an esterification reaction. The monomer component at this time was blended with terephthalic acid: ethylene glycol: tricyclo [5.2.1.0 (2,6)] decanedimethanol = 100: 112: 74 (molar ratio). Next, 0.525 g of antimony trioxide, 0.328 g of triethyl phosphate and 1.580 g of zinc acetate dihydrate were added as catalysts, and then the temperature of the system was raised to 250 ° C., and the pressure of the system was controlled at 0.4 MPa. Then, after the reaction for 3 hours, the pressure was gradually released, and the reaction was performed at normal pressure for 1 hour. Thereafter, the temperature was raised to 270 ° C. and gradually decreased to 13 Pa after 1 hour. Under this condition, the polycondensation reaction was continued, and after 2 hours and 30 minutes, the system was brought to atmospheric pressure with nitrogen gas, and 114.1 g of trimellitic anhydride (0.033 mol per 1 mol in total of all acid components) was added, The depolymerization reaction was performed by stirring at 255 ° C. for 2 hours. Thereafter, the system is put under pressure with nitrogen gas, the resin is discharged into a sheet shape, allowed to cool, pulverized with a crusher, a fraction having an opening of 1 to 6 mm is collected using a sieve, and a granular polyester resin is obtained. (A1) was obtained. The results are shown in Table 1.

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 TCD: tricyclo [5 .2.1.0 (2,6)] decanedimethanol TMA: trimellitic acid

Preparation Examples 2-18
Polyester resins (a2) to (a18) were obtained in the same manner as the polyester resin (a1) except that the charging composition was changed as shown in Table 1. The polyester resins (a2) to (a12), (a16), and (a18) are sufficiently cooled to room temperature, pulverized with a crusher, and a fraction having an opening of 1 to 6 mm is collected using a sieve. A granular polyester resin was obtained. Polyester resins (a13) to (a15) were discharged out of the system in a strand form and pelletized to obtain a pellet-like polyester resin. The polyester resin (a17) dispensed the resin into a sheet form. The results are shown in Table 1.

  Tables 2 and 3 show the final resin compositions and characteristic values of the obtained polyester resins (a1) to (a18).

[Preparation of aqueous dispersion of polyester resin]
Polyester resin aqueous dispersions (A-1) to (A-18) were obtained by the following procedure. Various evaluation was performed about the obtained polyester resin aqueous dispersion (A-1)-(A-18).

Preparation Example 19
[Self-emulsification process]
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 (a1), 220 g of isopropanol, triethylamine 24.1 g (corresponding to triethylamine equivalent to 3 times the acid value of the polyester resin (a1)) and 455.9 g of distilled water were placed in a glass container, respectively, and the stirring blade was kept at a rotational speed of 70 rpm and stirred. However, the temperature was raised through hot water in the jacket. When the internal temperature reached 80 ° C., the temperature was raised and stirring was continued for 180 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.
[Desolvation process]
Charge 800 g of the obtained dispersion of the polyester resin (a1) to a round bottom flask, and add 418 g of water and 9.4 g of triethanolamine (corresponding to 1 equivalent of triethylamine with respect to the acid value of the polyester resin (a1)). Then, a mechanical stirrer and a Liebig condenser were installed, the flask was heated in an oil bath, and 334 g of an aqueous medium was distilled off at normal pressure. Thereafter, the mixture is cooled to room temperature, and further stirred, 1.9 g of 28% by mass aqueous ammonia is added, and finally ion-exchanged water is added so that the solid content concentration becomes 30% by mass. A-1) was obtained and various evaluations were performed. The evaluation results are shown in Table 4.

Preparation Examples 20 to 36
The same operation as in Preparation Example 19 was performed except that the content of triethylamine was 3 times equivalent according to the acid value of the polyester resin to be used, and the stirring speed was changed in the range of 70 to 300 rpm. Thus, polyester resin dispersions (A-2) to (A-18) were obtained and subjected to various evaluations. The evaluation results are shown in Table 4.

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 5.

Examples 2 to 15 and Comparative Examples 1 to 3
The polyester resin aqueous dispersion was changed as shown in Table 5, and various characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 5.

Example 16
Silica particle aqueous dispersion (C-1) in which “Mizukasil P-50” (bulk specific gravity 0.32, average particle size 10 μm) manufactured by Mizusawa Chemical Co., Ltd. was dispersed in advance at a solid content of 20% by mass as silica particles (c1). Prepared. “Epocross WS-700” (solid content concentration 25% by mass) manufactured by Nippon Shokubai Co., Ltd. and silica particle aqueous dispersion (C-1) as aqueous polyester resin dispersion (A-1) and curing agent aqueous dispersion (B-2) ) Was mixed and stirred in accordance with the composition of Table 6 so that the solid content ratio was (a1) / (b1) / (c1) = 93.3 / 4.7 / 2 (% by mass), and the aqueous adhesive (S -1) was obtained. Various characteristics were evaluated. The results are shown in Table 6.

Examples 17 and 18
According to the composition of Table 6, the same operations as in Example 16 were performed to obtain aqueous adhesives (S-2) and (S-3), and various properties were evaluated. The results are shown in Table 6.

Example 19
The same operation as in Example 16 was carried out in accordance with the formulation shown in Table 6 except that “Elastolone BN-77” (solid content concentration: 30 to 32% by mass) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. was used as the aqueous hardener B-2. To obtain an aqueous adhesive (S-4), and various properties were evaluated. The results are shown in Table 6.

Example 20
As silica particles (c2), the same operation as in Example 16 was performed according to the formulation of Table 6 except that “Mizukasil P-527” (bulk specific gravity 0.19, average particle diameter 2 μm) manufactured by Mizusawa Chemical Industry was used. A water-based adhesive (S-5) was obtained and various properties were evaluated. The results are shown in Table 6.

Example 21
As silica particles (c3), the same operation as in Example 16 was performed according to the formulation shown in Table 6 except that “Mizukasil P-78D” (bulk specific gravity 0.24, average particle size 12 μm) manufactured by Mizusawa Chemical Industry was used. A water-based adhesive (S-6) was obtained and various properties were evaluated. The results are shown in Table 6.

Examples 22-25
According to the composition in Table 6, the same operations as in Example 16 were performed to obtain aqueous adhesives (S-7) to (S-10), and various properties were evaluated. The results are shown in Table 6.

Example 26
The formulation in Table 6 was followed. Without adding a curing agent, the same operation as in Example 16 was performed to obtain an aqueous adhesive (S-11), and various properties were evaluated. The results are shown in Table 6.

Example 27
The formulation in Table 6 was followed. Without adding silica particles, the same operation as in Example 16 was performed to obtain an aqueous adhesive (S-12), and various properties were evaluated. The results are shown in Table 6.

Example 28
A biaxially stretched PET film (Unitika) was prepared in the same manner as in Example 16 except that the coating conditions of the tabletop type coating apparatus (film applicator manufactured by Yasuda Seiki Co., Ltd .; No. 542-AB type, bar coater mounted) were changed. A resin film having a thickness of 0.05 μm was formed on a corona-treated surface (manufactured by Co., Ltd., thickness 50 μm), and various properties were evaluated. The results are shown in Table 6. 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 29
A biaxially stretched PET film (Unitika) was prepared in the same manner as in Example 16 except that the coating conditions of the tabletop type coating apparatus (film applicator manufactured by Yasuda Seiki Co., Ltd .; No. 542-AB type, bar coater mounted) were changed. A resin film having a thickness of 0.1 μm was formed on a corona-treated surface (manufactured by Co., Ltd., thickness 50 μm), and various properties were evaluated. The results are shown in Table 6. 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 30
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 6. 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 1-20 followed the predetermined | prescribed mixing | blending, the obtained water-based adhesive had good stability, and the resin film obtained from a water-based adhesive is excellent in easy-adhesiveness, transparency, blocking resistance, and water resistance. A film was formed. In particular, for Examples 16 to 25 and 28 to 30, since the polyester resin (A), the curing agent (B), and the silica particles (C) were respectively used in specific formulations, the resin film obtained from the aqueous adhesive was In addition to easy adhesion, transparency, blocking resistance, and water resistance, it was possible to form a coating film that had hot water resistance and slipperiness and was more excellent in terms of easy adhesion.

  In Comparative Example 1, since the compound represented by the general formula (I) was used as the glycol component of the polyester resin (A) at a content of less than 50%, the obtained resin film was inferior in easy adhesion.

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

Since the comparative example 3 used the alicyclic glycol different from the compound shown by general formula (I) as a glycol component of a polyester resin (A), the obtained resin film was inferior to easy-adhesiveness. .

Claims (7)

A polyester resin (A) mainly composed of a dicarboxylic acid component and a glycol component, an aqueous adhesive containing a basic compound and water and substantially free of an emulsifier, wherein the polyester resin (A) is a glycol component A water-based adhesive comprising 50 to 100 mol% of a compound represented by the following general formula (I), an acid value of 4 mgKOH / g or more, a glass transition temperature of 40 ° C or more, and a number average molecular weight of 5000 to 50000 .
(X ₁ and X ₂ are groups having 1 to 4 moles of alkylene oxide added to a hydroxyalkylene group having 1 to 4 carbon atoms and / or a hydroxyalkylene group having 1 to 4 carbon atoms. Also good)   2. The aqueous adhesive according to claim 1, comprising 1 to 10 mol% of a dicarboxylic acid having a sulfonate group with respect to 100 mol% of the dicarboxylic acid component constituting the polyester resin (A).   The aqueous adhesive according to claim 1 or 2, further comprising 1 to 10 parts by mass of the curing agent (B) with respect to 100 parts by mass of the nonvolatile component of the aqueous adhesive.   Furthermore, an inorganic particle (C) is contained, The water-based adhesive in any one of Claims 1-3 characterized by the above-mentioned.   A film formed by removing an aqueous medium from the aqueous adhesive according to claim 1.   A laminate obtained by forming the coating according to claim 5 on a substrate. The laminate according to claim 6, wherein an acrylic coating is further provided on the coating.