JP2014037479A - Aqueous polyester resin dispersion and method for manufacturing the same - Google Patents

Abstract

The present invention provides an aqueous polyester resin dispersion in which an aqueous dispersion of a resin different from a polyester resin, particularly an acrylic resin aqueous dispersion, is excellent in compatibility, and the resulting coating film has excellent water resistance.
A polyester resin aqueous dispersion containing a polyester resin, a basic compound and water and substantially free of an emulsifier, wherein the polyester resin has at least a carboxyl group in the molecule as a hydroxycarboxylic acid component. A compound having both hydroxyl groups, the compound having a total number of carboxyl groups and hydroxyl groups of 3 or more is contained in an amount of 0.2 to 5 mol% with respect to 100 mol% of the dicarboxylic acid component, and the number average molecular weight is 5000 to 50000, A polyester resin aqueous dispersion having an acid value of 4 mgKOH / g or more, a hydroxyl value of 4 mgKOH / g or more, and less than 1 mol% of dicarboxylic acid having a sulfonate group in the dicarboxylic acid component.
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Description

  The present invention relates to an aqueous dispersion of a resin different from a polyester resin, in particular, an aqueous polyester resin dispersion excellent in compatibility with an aqueous acrylic resin dispersion.

  Aqueous dispersions of polyester resins are widely used for applications such as paints, inks, adhesives, and coating agents.

  In recent years, in automotive applications and the like, studies have been made on coatings that take advantage of the excellent processability of polyester resins and the excellent weather resistance of acrylic resins. However, the polyester resin aqueous dispersion and the acrylic resin aqueous dispersion are difficult to mix uniformly, and there is a problem that a uniform film cannot be formed or the film becomes cloudy. Therefore, when mixing an aqueous dispersion of a polyester resin and an aqueous dispersion of an acrylic resin, compatibility is improved by adding an emulsifier or the like.

  For example, Patent Document 1 describes an aqueous base paint in which an aqueous dispersion of a polyester resin is added to an aqueous dispersion of an acrylic resin containing a nonionic modified polyolefin resin as an emulsifier.

JP 2012-7113 A

  However, since the water-based base paint as in Patent Document 1 contains an emulsifier, there is a problem that the obtained coating film is inferior in water resistance.

  An object of the present invention is to provide an aqueous dispersion of a resin different from a polyester resin, particularly an aqueous polyester resin dispersion excellent in compatibility with an aqueous acrylic resin dispersion.

  As a result of intensive studies in order to solve such problems, the present inventor has found that the above object can be achieved by using an aqueous dispersion of a specific polyester resin, and has reached the present invention.

That is, the gist of the present invention is as follows.
(1) A polyester resin aqueous dispersion containing a polyester resin composed of a dicarboxylic acid component, a glycol component and a hydroxycarboxylic acid component, a basic compound and water, and substantially free of an emulsifier, As a hydroxycarboxylic acid component, the following compound (I) is contained in an amount of 0.2 to 5 mol% based on 100 mol% of the dicarboxylic acid component, the number average molecular weight is 5000 to 50000, the acid value is 4 mgKOH / g or more, and the hydroxyl value is 4 mgKOH. Polyester resin aqueous dispersion, wherein the dicarboxylic acid component has less than 1 mol% of dicarboxylic acid having a sulfonate group in the dicarboxylic acid component.
Compound (I): a compound having at least both a carboxyl group and a hydroxyl group in the molecule, wherein the total number of carboxyl groups and hydroxyl groups is 3 or more.
(2) The polyester resin aqueous dispersion according to (1), wherein the acid value of the polyester resin is 4 to 20 mgKOH / g.
(3) The aqueous polyester resin dispersion according to (1) or (2), wherein the polyester resin has a hydroxyl value of 4 to 20 mgKOH / g.
(4) The aqueous polyester resin dispersion according to any one of (1) to (3), wherein the number of carboxyl groups in the compound (I) is larger than the number of hydroxyl groups.
(5) A resin film obtained by applying and drying the aqueous polyester resin dispersion according to any one of (1) to (4).
(6) A mixture of an aqueous dispersion obtained by mixing the aqueous polyester resin dispersion according to any one of (1) to (4) and an aqueous acrylic resin dispersion.
(7) A resin film obtained by applying and drying the mixture of the aqueous dispersion described in (6).
(8) It is composed of a dicarboxylic acid component, a glycol component and a hydroxycarboxylic acid component, and contains 0.2 to 5 mol% of the following compound (I) as a hydroxycarboxylic acid component with respect to 100 mol% of the dicarboxylic acid component. A polyester resin having an acid value of 4 mgKOH / g or more and a hydroxyl value of 4 mgKOH / g or more is dissolved in an organic solvent, and a basic compound and water are added and dispersed in the polyester resin solution. A method for producing an aqueous polyester resin dispersion.
Compound (I): a compound having at least both a carboxyl group and a hydroxyl group in the molecule, wherein the total number of carboxyl groups and hydroxyl groups is 3 or more.
(9) The method for producing an aqueous polyester resin dispersion according to (8), further comprising removing an organic solvent and / or a basic compound.
(10) An organic solvent having a boiling point of 180 ° C. or lower, a solubility in water at 20 ° C. of 5 g / L or more, and an azeotropic point with water of 60 to 150 ° C. is used. (8) The manufacturing method of the polyester resin aqueous dispersion as described in (9).

  The aqueous polyester resin dispersion of the present invention is excellent in compatibility with aqueous dispersions of other different resins, long-term storage stability, and film-forming properties. The resin film comprising the aqueous polyester resin dispersion of the present invention is excellent in water resistance, alcohol resistance and adhesiveness, and is a resin comprising a mixture of the aqueous polyester resin dispersion of the present invention and an aqueous dispersion of an acrylic resin. The coating is also excellent in water resistance. Furthermore, since the polyester resin aqueous dispersion of the present invention uses a dispersion medium containing water as a main component, the use of an organic solvent can be suppressed, and environmental protection and work environment can be improved.

Hereinafter, the present invention will be described in detail.
The aqueous polyester resin dispersion of the present invention (hereinafter sometimes simply referred to as “aqueous dispersion”) is obtained by dispersing a polyester resin in an aqueous medium.

  The polyester resin used in the present invention will be described. The polyester resin used in the present invention is composed of a dicarboxylic acid component, a glycol component, and a hydroxycarboxylic acid.

  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 resin film obtained from the aqueous dispersion 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 is remarkably lowered.

  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.

  Examples of the dicarboxylic acid component other than the dicarboxylic acid having a sulfonate group in the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, and 3-tert-butylisophthalic acid. , Aromatic dicarboxylic acids such as diphenic acid, oxalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, aicosane diacid, hydrogenated dimer acid, etc. Unsaturated aliphatic dicarboxylic acids such as acid, maleic acid, maleic anhydride, 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 dicar Phosphate and their anhydrides, include alicyclic dicarboxylic acids such as tetrahydrophthalic acid and its anhydride, among others, aromatic dicarboxylic acids are preferred. When aromatic dicarboxylic acid is used as the dicarboxylic acid component, the content is preferably 60 to 100 mol% in the dicarboxylic acid component in order to improve the alcohol resistance of the resin film obtained from the aqueous dispersion. These dicarboxylic acid components may be used alone or in combination.

  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.

  As the hydroxycarboxylic acid component, it is necessary to contain the compound (I). The compound (I) is a compound having both a carboxyl group and a hydroxyl group as functional groups in the molecule, and the total of the functional groups of the carboxyl group and the hydroxyl group is 3 or more. Examples of the compound (I) include 2-hydroxy sebacic acid, 5-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, citric acid, isocitric acid, malic acid, 2-methyl-2-hydroxysuccinic acid, tartaric acid, tetrahydroxy Adipic acid is mentioned. Especially, since the dispersion stability of an aqueous dispersion improves, it is preferable that the number of carboxyl groups is larger than the number of hydroxyl groups. Examples of such compounds include citric acid, isocitric acid, 2-hydroxy sebacic acid, 5-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, malic acid, and 2-methyl-2-hydroxysuccinic acid.

  The content of the compound (I) as the hydroxycarboxylic acid component needs to be 0.2 to 5 mol% with respect to 100 mol% of the dicarboxylic acid component, and preferably 0.25 to 4 mol%, It is more preferable to set it as 0.3-3 mol%. By setting the content of compound (I) to 0.2 to 5 mol%, an aqueous dispersion having excellent compatibility with aqueous dispersions of resins other than polyester resins and excellent storage stability can be obtained. . Moreover, the resin film obtained from an aqueous dispersion can be made excellent in film forming property, water resistance, alcohol resistance, and adhesiveness. When the content of compound (I) is less than 0.2 mol%, compatibility with aqueous dispersions of resins other than polyester resins, storage stability of aqueous dispersions, film-forming properties of resin films obtained therefrom, Any one of water resistance, alcohol resistance, and adhesiveness, or any of them is inferior, which is not preferable. On the other hand, when the content of the compound (I) exceeds 5 mol%, it is not preferable because the film-forming property and adhesiveness of the resin film are low.

  In the present invention, as the hydroxycarboxylic acid component, a hydroxycarboxylic acid other than the compound (I), that is, an aliphatic lactone or a monohydroxymonocarboxylic acid may be contained within a range not impairing the characteristics of the present invention. Examples of the aliphatic lactone include ε-caprolactone, δ-valerolactone, and γ-valerolactone. Examples of the monohydroxymonocarboxylic acid include alkylene oxide adducts of lactic acid, β-hydroxybutyric acid, p-hydroxybenzoic acid, and 4-hydroxyphenyl stearic acid. When an aliphatic lactone or monohydroxymonocarboxylic acid is used, the content thereof is preferably 50 mol% or less, more preferably 40 mol% or less, more preferably 30 mol, relative to 100 mol% of the dicarboxylic acid component. % Or less is more preferable.

  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 a monocarboxylic acid or monoalcohol is used at the time of depolymerization, the acid value and / or the hydroxyl 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 a trifunctional or higher carboxylic acid or a trifunctional or higher alcohol is charged before the esterification reaction, the content is preferably less than 1 mol% with respect to 100 mol% of the dicarboxylic acid component and the glycol component, respectively. . In general, 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. It may disappear. 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 component and a glycol component, respectively. It is preferable.

  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 mgKOH / g or more in order to improve the dispersibility of the aqueous dispersion and long-term storage stability, and is preferably 4 to 20 mgKOH / g. 4 to 15 mgKOH / g is more preferable, and 4 to 10 mgKOH / g is even more preferable. When the acid value of the polyester resin is less than 4 mgKOH / g, uniform dispersion in an aqueous medium becomes difficult, or even if it can be dispersed, the storage stability of the aqueous dispersion is inferior.

  The hydroxyl value of the polyester resin used in the present invention is required to be 4 mgKOH / g or more in order to improve the compatibility with an aqueous dispersion of a resin other than the polyester resin, and should be 4 to 20 mgKOH / g. It is preferably 4 to 15 mgKOH / g, more preferably 4 to 10 mgKOH / g. When the hydroxyl value of the polyester resin is less than 4 mgKOH / g, the compatibility with an aqueous dispersion of a resin other than the polyester resin is inferior.

  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. On the other hand, if it exceeds 50000, the storage stability of the aqueous dispersion becomes poor, such being undesirable.

  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.

  As a glass transition temperature of the polyester resin used for this invention, it is preferable to set it as -50-120 degreeC, and it is more preferable to set it as -30-100 degreeC from the handleability at the time of manufacture. When the aqueous dispersion of the present invention is used as an intermediate layer of a laminate, the toughness of the resin film and the adhesiveness at low temperature are more excellent, and therefore it is preferably −50 to 40 ° C. When using, since the hardness of the resin film obtained is more excellent, it is more preferable to set it as 40-120 degreeC.

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

  The polyester resin used for this invention can be manufactured by a well-known method combining the said monomer. 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 in which a depolymerization reaction is carried out by adding compound (I) 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.

  Compound (I) is preferably used only for the depolymerization reaction. Although it is possible to charge the compound (I) before the esterification reaction and proceed with the polycondensation reaction, in that case, the degree of dispersion of the resulting polyester resin may exceed 10. By using the compound (I) in the depolymerization reaction, a polyester resin having a desired acid value, hydroxyl value, and number average molecular weight can be obtained efficiently.

  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. For example, anionic surfactants include higher alcohol sulfates, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfates. Salt, vinyl sulfosuccinate, nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid Compounds having a polyoxyethylene structure such as amides, ethylene oxide-propylene oxide copolymers, and sorbitan derivatives can be mentioned, and amphoteric surfactants include lauryl Tyne, lauryl dimethyl amine 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, and 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 is preferably 5 to 50% by mass, and more preferably 15 to 40% by mass. 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 the aqueous polyester resin dispersion in the present invention include phase inversion emulsification and self-emulsification. 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). Is the way to get. The self-emulsification method is a method for preparing a polyester resin aqueous dispersion containing an organic solvent by charging a polyester resin, a basic compound, an organic solvent and water all at once and heating the system while stirring. .

  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 present invention, since an aqueous dispersion can be easily obtained, it is more preferable to use a phase inversion emulsification method.

  In the production of the aqueous dispersion of the present invention, a step of removing the organic solvent and / or the basic compound (solvent removal step) may be further provided after each of the above emulsification steps. In general, when the organic solvent remains in the aqueous dispersion, the storage stability of the aqueous dispersion is poor. Therefore, when using the phase inversion emulsification method, it is preferable to provide a solvent removal step. The organic solvent content after the solvent removal step is preferably less than 1% by mass of the aqueous dispersion.

  In the production of the aqueous dispersion of the present invention, 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.

  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.

  The organic solvent that dissolves the polyester resin preferably has a boiling point of 180 ° C. or lower, and 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.

  Moreover, it is more preferable that the organic solvent has an azeotropic point with water of 60 to 150 ° C. 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, the concentration of the polyester resin in the obtained solution is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, and 30 to 50% by mass. More preferably. 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.

  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.

  Examples of a method for dispersing an organic solvent solution of a polyester resin in an aqueous medium together with a basic compound include, for example, a method in which a basic compound is added to an organic solvent solution of a polyester resin and an aqueous medium is gradually added thereto. In addition, a method may be mentioned in which a basic compound is added to an aqueous medium, and this is gradually added to an organic solvent solution of a polyester resin. Above all, in order to prevent non-uniform mixing of the polyester resin organic solvent solution and the basic compound, the basic compound is added to the polyester resin organic solvent solution, and the aqueous medium is gradually added thereto. Thus, a method of performing phase inversion emulsification is preferable.

  The basic compound used in the phase inversion emulsification step is preferably one that can neutralize 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 1 to 20 times the equivalent of the acid value of the polyester resin used. By adding a basic compound in this range, 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.

  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 the mass of the polyester resin is set to 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. Can be uniformly dispersed while suppressing the formation of.

  The solid content concentration of the aqueous polyester resin dispersion after phase inversion emulsification is preferably 5 to 60% by mass. By setting the solid content concentration in this range, aggregation of the polyester resin can be suppressed in the subsequent solvent removal step.

  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.

  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.

  In the production method of the present invention, a filtration step can be provided after the dispersion step for the purpose of removing foreign substances and the like. In such a case, for example, a 600-mesh stainless steel filter (filtration accuracy: 25 μm, twill weave) may be installed, and atmospheric pressure filtration or pressure (air pressure 0.2 MPa) filtration may be performed. A filtration process may be provided immediately after a dispersion | distribution process, and when providing the above-mentioned solvent removal process, you may provide after a solvent removal process.

  Various additives may be blended in the aqueous dispersion of the present invention. Examples of the additive include a stabilizer, a repellency inhibitor, a leveling agent, an antifoaming agent, a pigment dispersant, an ultraviolet absorber, and a lubricant. For example, the storage stability of the aqueous dispersion can be improved by adding aqueous ammonia to the aqueous dispersion of the present invention as a stabilizer.

  Moreover, you may mix | blend a hardening | curing agent with the aqueous dispersion of this invention as needed. The curing agent is not particularly limited as long as it is a functional group possessed by a polyester resin, such as a carboxyl group or its anhydride and a hydroxyl group, and is not particularly limited, such as urea resin, melamine resin, benzoguanamine resin, etc. Examples thereof include amino resins, polyfunctional epoxy compounds, polyfunctional isocyanate compounds and various block isocyanate compounds thereof, polyfunctional aziridine compounds, carbodiimide group-containing compounds, oxazoline group-containing polymers, and phenol resins. These may be used alone or in combination. In particular, the present invention is an aqueous dispersion of a polyester resin blended with the compound (I), and thus has a large number of functional groups such as carboxyl groups and hydroxyl groups, so that the reactivity with the above curing agent is very high. It is good.

  Next, a method for using the aqueous dispersion of the present invention will be described.

  Examples of the method for forming the resin film of the present invention include a gravure coating method, a Mayer bar coating method, a dipping method, a brush coating method, a spray coating method, and a curtain flow coating method. By uniformly coating the surface of various substrates by these methods, setting it at around room temperature as necessary, and then subjecting it to heat treatment for drying and baking, the uniform resin film is adhered to the surface of various substrates. Can be formed. As a heating device at this time, a normal hot air circulation 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 substrate to be coated, etc. In consideration of economy, the heating temperature is usually 60 to 250 ° C., 70 It is preferable to set it to -230 degreeC, and it is more preferable to set it as 80-200 degreeC. The heating time is usually 1 second to 30 minutes, preferably 5 seconds to 20 minutes, and more preferably 10 seconds to 10 minutes.

  The thickness of the resin film formed using the aqueous dispersion of the present invention is appropriately selected depending on the purpose and application, but is usually 0.01 to 40 μm and 0.1 to 30 μm. Is preferable, and it is more preferable to set it as 0.5-20 micrometers.

  Since the polyester resin aqueous dispersion of the present invention is excellent in each characteristic, it can be suitably used as an adhesive layer or a surface layer of a food packaging laminate requiring a boil / retort treatment, and a binder for automobile paints.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
The evaluation and measurement methods are as follows.

(1) Composition of polyester resin By using ¹ H-NMR analysis using a high resolution nuclear magnetic resonance apparatus (manufactured by JEOL Ltd., ECA500 NMR), the resin composition was obtained 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 and 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) Hydroxyl value of polyester resin 3 g of polyester resin is precisely weighed, 0.6 mL of acetic anhydride and 50 mL of pyridine are added, and the mixture is allowed to react at room temperature for 48 hours, followed by addition of 5 mL of distilled water. By continuing stirring at room temperature for 6 hours, all acetic anhydride that was not used in the reaction was also changed to acetic acid. To this solution, 50 mL of 1,4-dioxane was added, titrated with potassium hydroxide using cresol red thymol blue as an indicator, and the amount of potassium hydroxide consumed for neutralization (W ₁ ) From the amount of potassium hydroxide (calculated value: W ₀ ) required for neutralization when the amount of acetic anhydride charged does not react with the polyester resin and becomes all acetic acid, the difference (W ₀ −W) ₁ ) was determined by the number of mg of potassium hydroxide, and the value obtained by dividing this by the number of g of the polyester resin was defined as the hydroxyl value.

(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 number average molecular weight (Mn) and the weight average molecular weight (Mw), the degree of dispersion and the number average degree of polymerization were determined by the following equations.
Dispersity = Mw / Mn

(5) Glass transition temperature of polyester resin 10 mg of polyester resin is used as a sample, and the temperature rising rate is 10 using an input compensation type differential scanning calorimeter (Diamond DSC, detection range: −50 to 200 ° C., manufactured by Perkin Elmer). Measured under the conditions of ° C / min. The point where the slope of the straight line in the temperature rise curve obtained by extending the low temperature side baseline to the high temperature side and the curve of the step change part of the glass transition is maximized. The temperature at the point of intersection with the tangent drawn in step 1 was determined and used as the glass transition temperature.

(6) Solid content concentration of polyester resin aqueous dispersion About 1 g of polyester resin aqueous dispersion was weighed (X ₁ g), and this was dried at 150 ° C. for 2 hours to weigh the residue (Y ₁ g), and the solid content concentration was determined by the following equation.
Solid content concentration (% by mass) = (Y ₁ / X ₁ ) × 100

(7) pH of aqueous polyester resin dispersion
Using a pH meter (F-21, manufactured by Horiba, Ltd.), the pH of the aqueous polyester resin dispersion was measured at a measurement temperature of 25 ° C. after calibrating with standard buffer solutions of pH 7 and pH 9 (manufactured by Nacalai Tesque).

(8) Volume average particle diameter and number average particle diameter of aqueous polyester resin dispersion Dilute with water so that the concentration of the polyester resin in the aqueous polyester resin dispersion is 0.1% by mass, and measure the laser diffraction particle diameter. The volume average particle diameter and the number average particle diameter were measured using an apparatus (manufactured by Nikkiso Co., Ltd., MICROTRAC UPA (model 9340-UPA)). 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 .

(9) Storage stability of aqueous polyester resin dispersion 30 g of aqueous polyester resin dispersion was sealed in a 50 mL glass sample bottle and stored at 25 ° C. for 180 days. After storage, the supernatant was collected from the sample bottle, the solid content concentration was measured, the ratio of the precipitated polyester resin was calculated by the following formula, and evaluated according to the following criteria.
Ratio of precipitated polyester resin (mass%) = {solid content concentration before storage (mass%) − solid content concentration after storage (mass%)} / {solid content concentration before storage (mass%)}
◎: Less than 0.1% by mass ○: 0.1% by mass or more and less than 0.5% by mass Δ: 0.5% by mass or more and less than 1.0% by mass ×: 1.0% by mass or more

(10) Film-formability of resin coating Polyester resin aqueous dispersion is coated on a non-treated surface of a biaxially stretched PET film (manufactured by Unitika Co., Ltd., 50 μm thick) with a desktop coating device (manufactured by Yasuda Seiki Co., Ltd. No. 542-AB type ", equipped with a bar coater), followed by drying for 2 minutes in a hot air dryer set at 100 ° C. to form a resin film having a thickness of 3 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 (Perkin Elmer, “SYSTEM2000”, using Ge60 ° 50 × 20 × 2 mm prism), the resin film adhered 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 (manufactured by Union Tool, “MICROFINE”), and after forming the resin film on the film using an aqueous dispersion, The thickness of the base material having this resin coating was measured by the same method and determined by the difference.
(Double-circle): Neither crack, fine unevenness | corrugation, appearance defects, such as whitening, and peeling of the resin film by an adhesive tape are recognized.
○: Any of cracks, fine irregularities, appearance defects such as whitening, and peeling of the resin film with an adhesive tape are observed.
X: Cracks, fine irregularities, appearance defects such as whitening, and peeling of the resin film with an adhesive tape are all recognized.

(11) Water resistance of resin coating The same operation as in (10) was performed to form a resin coating having a thickness of 3 µm on the PET film.
The obtained PET film on which the resin film was formed was immersed in distilled water at 25 ° C., gently pulled up after 30 minutes and air-dried, and then the appearance of the resin film was visually observed and evaluated according to the following criteria. .
A: No change in appearance.
◯: Although the surface state 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) Alcohol resistance of resin coating The PET film on which the resin coating obtained in (11) is formed is immersed in isopropyl alcohol at 25 ° C., gently pulled up after 30 minutes, and air-dried. Were visually observed and evaluated according to the following criteria.
A: No change in appearance.
○: Although the surface state was changed (the surface was clouded white, etc.), the resin film did not dissolve or swell.
X: The resin film was dissolved or swollen.

(13) Adhesiveness of resin film Two PET films on which the resin film obtained in (11) is formed are prepared and stacked so that the polyester resin film surfaces are in contact with each other, and a heat press machine (seal pressure 0.2 MPa) For 10 seconds) at 100 ° C. to produce a laminate.
After that, the laminate was allowed to stand for 1 day in an atmosphere of 20 ° C. and 60% RH, then cut to a width of 25 mm, and pulled at 20 ° C. using a tensile tester (Intesco precision universal testing machine type 2020). A 180 degree peel test was performed at a speed of 50 mm / min, and the peel strength was measured.
Practically, the peel strength of the pressed laminate is required to be 8 N / 25 mm or more, preferably 10 N / 25 mm or more, and more preferably 15 N / 25 mm or more.

(14) Compatibility 100 g of an aqueous polyester resin dispersion and 100 g of an acrylic resin aqueous dispersion (NeoCryl A-6015, manufactured by Neo Resins DSM Co., Ltd.) are mixed with a stirrer (Tokyo Science Instruments, Mazela NZ-). 1200) and stirred and mixed at room temperature (25 ° C.) at a rotation speed of 30 rpm for 1 hour. Using the obtained mixture, the same operation as in the above (10) was performed to form a resin film having a film thickness of 3 μm. This resin film was visually observed to evaluate the appearance.
In addition, an aqueous acrylic resin dispersion is made of an aqueous polyolefin resin dispersion (SB-1200, manufactured by Unitika), an aqueous melamine resin (Cymel 325, manufactured by Mitsui Cytec Industries), an aqueous polyurethane resin dispersion (Superflex 300, No. 1). The same evaluation was carried out by changing to an aqueous epoxy resin dispersion (Deconal EX-711, manufactured by Nagase ChemteX) and an aqueous isocyanate resin (Elastotron BN69, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).
(Double-circle): Even if a liquid mixture is left still for one day, it is uniform by one layer. Also, the resin coating is not whitened.
○: Even if the mixed solution is allowed to stand for 1 day, it is uniform in one layer, but the resin film is whitened.
X: When the mixed solution is allowed to stand for 1 day, it is separated into two layers.

(15) Water resistance of a resin film obtained by applying and drying a mixture of an aqueous acrylic resin dispersion and an aqueous polyester resin dispersion, instead of the aqueous polyester dispersion, the aqueous acrylic resin dispersion obtained in (14) above A resin film having a thickness of 3 μm was formed on the PET film by performing the same operation as in the above (10) except that the mixture of the body and the aqueous polyester resin dispersion was used.
The obtained PET film on which the resin film was formed was immersed in distilled water at 25 ° C., gently pulled up after 30 minutes and air-dried, and then the appearance of the resin film was visually observed and evaluated according to the following criteria. .
A: No change in appearance.
◯: Although the surface state was changed (the surface became cloudy white, etc.), the resin film did not dissolve or swell.
X: The resin film was dissolved or swollen.

The polyester resin used in Examples and Comparative Examples was obtained as follows.
Polyester resin A
A mixture consisting of 2492 g of terephthalic acid (TPA), 623 g of isophthalic acid (IPA), 1263 g of sebacic acid (SEA), 1354 g of neopentyl glycol (NPG), and 1040 g of ethylene glycol (EG) was heated in an autoclave at 235 ° C. for 6 hours. The esterification reaction was performed. The charged resin composition was TPA / IPA / SEA / NPG / EG = 60/15/25/52/67 (molar ratio). Next, 3.3 g of zinc acetate dihydrate (6.0 × 10 ⁻⁴ mol per mol of dicarboxylic acid component) was added as a catalyst, the temperature of the system was raised to 245 ° C., and the pressure of the system was gradually increased. The pressure was 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 the temperature reached 180 ° C., 38 g of citric acid (a total of 200 mol parts of dicarboxylic acid component and glycol component). 0.4 mol part) was added and stirred at 180 ° C. for 2 hours to carry out a depolymerization reaction. Thereafter, the system was put under pressure with nitrogen gas, and the resin was dispensed in a sheet form to obtain polyester resin A.

Polyester resin B
A mixture consisting of 2077 g of TPA, 2077 g of IPA, 1666 of NPG, and 853 g of EG was heated in an autoclave at 240 ° C. for 5 hours to carry out an esterification reaction. The charged resin composition was TPA / IPA / NPG / EG = 50/50/64/55 in terms of molar ratio. Next, 3.3 g of zinc acetate dihydrate (6.0 × 10 ⁻⁴ mol per mol of dicarboxylic acid component) is added as a catalyst, the temperature of the system is raised to 260 ° C., and the pressure of the system is gradually increased. The pressure was reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction is continued, and after 6 hours, the system is brought to atmospheric pressure with nitrogen gas, the temperature of the system is lowered, and when the temperature reaches 200 ° C., 20 g of malic acid (total 200 mol parts of dicarboxylic acid component and glycol component) 0.3 mol part) was added and stirred at 200 ° C. for 2 hours to carry out a depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas, and the polyester resin was discharged in the form of a strand. After cooling with water, cutting was performed to obtain a polyester resin B in a pellet form (diameter: about 3 mm, length: about 3 mm).

Polyester resin C
A mixture consisting of 2907 g of TPA, 1246 g of IPA, NPG 1666, and 853 g of EG was heated in an autoclave at 240 ° C. for 5 hours to carry out an esterification reaction. The charged resin composition was TPA / IPA / NPG / EG = 70/30/64/55 in terms of molar ratio. Next, 3.3 g of zinc acetate dihydrate (6.0 × 10 ⁻⁴ mol per mol of dicarboxylic acid component) is added as a catalyst, the temperature of the system is raised to 260 ° C., and the pressure of the system is gradually increased. The pressure was reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was further continued. After 5 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when the temperature reached 270 ° C., 68 g of 5-hydroxyisophthalic acid (total of dicarboxylic acid component and glycol component) 0.75 mol part relative to 200 mol parts) was added and stirred at 270 ° C. for 3 hours to carry out a depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. This was sufficiently cooled to room temperature, then pulverized with a crusher, and a fraction having an opening of 1 to 6 mm was collected using a sieve to obtain a granular polyester resin C.

Polyester resin D, H ~ K
Polyester resins D and H to K were obtained in the same manner as polyester resin A, except that the charging composition was changed as shown in Table 1.

Polyester resin E, G, M ~ Q
Polyester resins E, G, and M to O were obtained in the same manner as the polyester resin B, except that the charging composition was changed as shown in Table 1.

Polyester resin F, L, P
Polyester resins F and L were obtained in the same manner as the polyester resin C, except that the charging composition was changed as shown in Table 1.

  The charged compositions of the polyester resins A to Q are shown in Table 1, and the final composition of the obtained polyester resin and its characteristic values are shown in Table 2.

In Tables 1 to 3, abbreviations indicate the following.
TPA: terephthalic acid IPA: isophthalic acid SIPA-Na: 5-sodium sulfoisophthalic acid ADA: adipic acid SEA: sebacic acid EG: ethylene glycol NPG: neopentyl glycol BAEO: 2,2-bis [4- (hydroxyethoxy) phenyl ] Ethylene oxide adduct of propane (bisphenol A) PTMG: polytetramethylene glycol (molecular weight: 1000)
CIA: citric acid MAA: malic acid 5-HIA: 5-hydroxyisophthalic acid THADA: tetrahydroxyadipic acid TMA: trimellitic acid TMP: trimethylolpropane TEA: triethylamine BA: dibutylamine MEK: methyl ethyl ketone NP: N-methylpyrrolidone

Example 1
[Dissolution process]
400 g of polyester resin A and 600 g of methyl ethyl ketone are put into a 2 L polyethylene container, and heated and stirred so that the temperature in the system becomes 50 ° C., and the polyester resin is completely dissolved in methyl ethyl ketone. An organic solvent solution of the resin was obtained.
[Phase inversion emulsification process]
500 g of an organic solvent solution of a polyester resin is charged into a glass container (internal volume 2 L) and stirred while maintaining the internal temperature at 17 ° C., and 15.1 g of triethylamine as a basic compound (6% of the acid value of the polyester resin). Equivalent to double equivalents) was added. Subsequently, 550 g of distilled water at 17 ° C. was added at a rate of 40 g / min, and then stirring was continued for 30 minutes to obtain an aqueous polyester resin dispersion. The system temperature during the addition of the entire amount of distilled water was 17 ± 1 ° C.
[Desolvation process]
800 g of the obtained polyester resin aqueous 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 while stirring, 0.6 g of 28% by mass aqueous ammonia is added, and then distilled water is added so that the solid content concentration becomes 30% by mass, and the liquid in the flask is 600 mesh. Was filtered through a stainless steel filter to obtain an aqueous polyester resin dispersion.

Example 2
Using polyester resin B instead of polyester resin A in the dissolving step, changing triethylamine charged in the phase inversion emulsifying step to 6.5 g (corresponding to 3 times equivalent of amine with respect to the acid value of the polyester resin), Except for changing the distilled water to 559 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, phase inversion emulsification using it, and solvent removal. An aqueous polyester resin dispersion was obtained.

Example 3
The polyester resin C is used in place of the polyester resin A in the dissolution step, and the triethylamine charged in the phase inversion emulsification step is changed to 6.1 g (corresponding to 1.2 times equivalent of amine with respect to the acid value of the polyester resin). In addition, except that the distilled water is changed to 559 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, and phase-invert emulsification using the polyester resin to remove the solvent. Thus, an aqueous polyester resin dispersion was obtained.

Example 4
Using polyester resin D in place of polyester resin A in the dissolving step, changing triethylamine charged in the phase inversion emulsifying step to 13.0 g (corresponding to 6 times equivalent of amine with respect to the acid value of the polyester resin), Except for changing the distilled water to 552 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, phase inversion emulsification using it, and solvent removal. An aqueous polyester resin dispersion was obtained.

Example 5
Using polyester resin E instead of polyester resin A in the dissolution step, changing triethylamine charged in the phase inversion emulsification step to 8.7 g (equivalent to 3 times equivalent of amine to the acid value of the polyester resin), Except for changing the distilled water to 557 g in the solvent removal step, the same operation as in the production method of Example 1 is performed, the polyester resin is dissolved, phase-inverted and emulsified using it, and the solvent is removed. An aqueous polyester resin dispersion was obtained.

Example 6
Use polyester resin F instead of polyester resin A in the dissolution step, 13.0 g of triethylamine charged in the phase inversion emulsification step (corresponding to 1.2 times equivalent of amine with respect to the acid value of the polyester resin), solvent removal A polyester resin is prepared by performing the same operation as in the production method of Example 1 except that the distilled water is changed to 552 g in the process, dissolving the polyester resin, phase inversion emulsification using the polyester resin, and removing the solvent. An aqueous dispersion was obtained.

Example 7
Using polyester resin G in place of polyester resin A in the dissolution step, 5.4 g of triethylamine charged in the phase inversion emulsification step (corresponding to 3 times equivalent of amine with respect to the acid value of the polyester resin), in the solvent removal step Except for changing distilled water to 560 g, the same operation as in the production method of Example 1 was performed to dissolve the polyester resin, phase inversion emulsification using the polyester resin, and solvent removal, thereby aqueous dispersion of the polyester resin. Got the body.

Example 8
Using polyester resin H instead of polyester resin A in the dissolving step, changing triethylamine charged in the phase inversion emulsifying step to 8.7 g (equivalent to 6 times equivalent of amine to the acid value of the polyester resin), Except for changing the distilled water to 557 g in the solvent removal step, the same operation as in the production method of Example 1 is performed, the polyester resin is dissolved, phase-inverted and emulsified using it, and the solvent is removed. An aqueous polyester resin dispersion was obtained.

Example 9
Using polyester resin I instead of polyester resin A in the dissolution step, changing triethylamine charged in the phase inversion emulsification step to 17.3 g (corresponding to 6 times equivalent of amine to the acid value of the polyester resin), Except for changing the distilled water to 548 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, phase inversion emulsification using it, and solvent removal. An aqueous polyester resin dispersion was obtained.

Example 10
A polyester resin was prepared in the same manner as in the production method of Example 1 except that N-methylpyrrolidone (solubility: infinite, boiling point: 202 ° C., azeotropic point: none) was used instead of methyl ethyl ketone in the dissolving step. Was dissolved in the solution, phase-inverted and emulsified using the solution, and the solvent was removed to obtain an aqueous polyester resin dispersion.

Example 11
19.3 g of dibutylamine (boiling point: 159.6 ° C.) (six times equivalent to the acid value of the polyester resin) is used in place of triethylamine in the phase inversion emulsification step, and the amount of distilled water in the solvent removal step is 546 g. The polyester resin aqueous dispersion was obtained by performing operation similar to the manufacturing method of Example 1 except melt | dissolving, melt | dissolving a polyester resin, carrying out phase inversion emulsification using it, and removing a solvent. .

Example 12
In the solvent removal step, the same operation as in the production method of Example 1 is performed except that 28% aqueous ammonia to be added is not added, the polyester resin is dissolved, phase-inverted and emulsified using it, and the solvent is removed. As a result, an aqueous polyester resin dispersion was obtained.

Comparative Example 1
Using polyester resin J instead of polyester resin A in the dissolving step, changing triethylamine charged in the phase inversion emulsifying step to 13.0 g (corresponding to 6 times equivalent of amine with respect to the acid value of the polyester resin), Except for changing the distilled water to 552 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, phase inversion emulsification using it, and solvent removal. An aqueous polyester resin dispersion was obtained.

Comparative Example 2
Using polyester resin K instead of polyester resin A in the dissolution step, changing triethylamine charged in the phase inversion emulsification step to 4.3 g (corresponding to 6 times equivalent of amine to the acid value of the polyester resin), Except for changing the distilled water to 561 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, phase inversion emulsification using it, and solvent removal. An aqueous polyester resin dispersion was obtained.

Comparative Example 3
The polyester resin L is used in place of the polyester resin A in the dissolution step, and the triethylamine charged in the phase inversion emulsification step is changed to 19.0 g (corresponding to 1.2 times equivalent of amine with respect to the acid value of the polyester resin). In addition, except that the distilled water is changed to 546 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, and phase-invert emulsification using the polyester resin to remove the solvent. Thus, an aqueous polyester resin dispersion was obtained.

Comparative Examples 4 and 6
In place of polyester resin A in the dissolution step, polyester resins M and O are used, respectively, and 8.7 g of triethylamine charged in the phase inversion emulsification step (corresponding to 3 times equivalent of amine with respect to the acid value of the polyester resin) Except that the distilled water is changed to 557 g in the solvent removal step, the same operation as in the production method of Example 1 is performed, the polyester resin is dissolved, phase-inverted and emulsified using the polyester resin, By carrying out a solvent, an aqueous polyester resin dispersion was obtained.

Comparative Example 5
Using polyester resin N in place of polyester resin A in the dissolving step, changing triethylamine charged in the phase inversion emulsifying step to 2.2 g (corresponding to 3 times equivalent of amine to the acid value of the polyester resin), Except for changing the distilled water to 563 g in the solvent removal step, the same operation as in the production method of Example 1 was performed to try to disperse the polyester resin. However, the polyester resin aggregated and settled during the dispersion. An aqueous polyester resin dispersion could not be obtained.

Comparative Example 7
Using polyester resin P instead of polyester resin A in the dissolution step, changing triethylamine charged in the phase inversion emulsification step to 17.3 g (corresponding to 3 times equivalent amine to the acid value of the polyester resin), Except for changing the distilled water to 548 g in the solvent removal step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, phase inversion emulsification using it, and solvent removal. An aqueous polyester resin dispersion was obtained.

Comparative Example 8
Except for using the polyester resin Q in place of the polyester resin A in the dissolution step, the same operation as in the production method of Example 1 is performed to dissolve the polyester resin, and phase-invert emulsification using it to remove the solvent. As a result, an aqueous polyester resin dispersion was obtained.

Comparative Example 9
In the phase inversion emulsification step, a polyester resin was prepared by performing the same operation as in the production method of Comparative Example 6 except that 25 g of a surfactant (manufactured by Aldrich, “IgepalCO720”) was added as a starting material. The polyester resin aqueous dispersion was obtained by melt | dissolving, carrying out phase inversion emulsification using it, and removing a solvent.

  Table 3 shows the characteristics of the polyester resin aqueous dispersions obtained in Examples 1 to 12 and Comparative Examples 1 to 9, and the characteristics of the resin film obtained using the aqueous dispersion.

  The aqueous dispersions of Examples 1 to 12 are not only excellent in compatibility with an aqueous dispersion of a resin different from the polyester resin and long-term storage stability, but also a resin film obtained by coating and drying it. Excellent film properties, water resistance, alcohol resistance, and adhesion. In addition, since the resin coating is obtained from an aqueous dispersion, the burden on the environment is small.

  In the aqueous dispersion of Comparative Example 1, the number average molecular weight of the polyester resin used was higher than the range specified in the present invention. Therefore, the obtained aqueous dispersion was inferior in storage stability. Moreover, it was inferior to the compatibility with the aqueous epoxy resin dispersion.

  In Comparative Example 2, since the content of the compound (I) in the polyester resin used was lower than the range defined in the present invention, the acid value and hydroxyl value of the polyester resin were less than 4 mgKOH / g. Therefore, the obtained aqueous dispersion was inferior in storage stability. Moreover, the compatibility with any aqueous dispersion was poor.

  In Comparative Example 3, since the content of the compound (I) in the polyester resin used was higher than the range defined in the present invention, the number average molecular weight of the polyester resin was less than 5000. Therefore, the obtained resin film was inferior in film forming property and adhesiveness.

  In Comparative Example 4, the polyester resin used did not contain compound (I), and the hydroxyl value of the polyester resin was less than 4 mgKOH / g. Therefore, the obtained aqueous dispersion was inferior in compatibility with the acrylic resin aqueous dispersion.

  In Comparative Example 5, the polyester resin used did not contain compound (I), and the acid value of the polyester resin was less than 4 mgKOH / g. Therefore, the polyester resin aggregated and settled during dispersion, and an aqueous dispersion could no longer be obtained.

  In Comparative Examples 6 and 8, the polyester resin used did not contain compound (I). Therefore, the obtained aqueous dispersion was inferior in compatibility with the acrylic resin aqueous dispersion.

  In Comparative Example 7, since the content of the dicarboxylic acid having a sulfonate group in the polyester resin used was 1 mol% or more of the total dicarboxylic acid component, the obtained resin film had poor water resistance. It was.

  Since the aqueous dispersion of Comparative Example 9 contained an emulsifier, the resulting resin film was inferior in water resistance.

Claims (10)

A polyester resin aqueous dispersion containing a polyester resin composed of a dicarboxylic acid component, a glycol component and a hydroxycarboxylic acid component, a basic compound, and water, and substantially free of an emulsifier. As an acid component, 0.2-5 mol% of the following compound (I) is contained with respect to 100 mol% of the dicarboxylic acid component, the number average molecular weight is 5000-50000, the acid value is 4 mgKOH / g or more, and the hydroxyl value is 4 mgKOH / g or more. A polyester resin aqueous dispersion, wherein the dicarboxylic acid component contains less than 1 mol% of dicarboxylic acid having a sulfonate group.
Compound (I): a compound having at least both a carboxyl group and a hydroxyl group in the molecule, wherein the total number of carboxyl groups and hydroxyl groups is 3 or more. The polyester resin aqueous dispersion according to claim 1, wherein the polyester resin has an acid value of 4 to 20 mgKOH / g. The polyester resin aqueous dispersion according to claim 1 or 2, wherein the polyester resin has a hydroxyl value of 4 to 20 mgKOH / g. The polyester resin aqueous dispersion according to any one of claims 1 to 3, wherein the number of carboxyl groups in the compound (I) is larger than the number of hydroxyl groups. A resin film obtained by applying and drying the aqueous polyester resin dispersion according to claim 1. A mixture of an aqueous dispersion obtained by mixing the aqueous polyester resin dispersion according to claim 1 and an aqueous acrylic resin dispersion. A resin film obtained by applying and drying the mixture of the aqueous dispersion according to claim 6. It is composed of a dicarboxylic acid component, a glycol component, and a hydroxycarboxylic acid component. As the hydroxycarboxylic acid component, the following compound (I) is contained in an amount of 0.2 to 5 mol% with respect to 100 mol% of the dicarboxylic acid component, and the number average molecular weight is 5000 to 5000. A polyester resin characterized in that a polyester resin having an acid value of 4 mgKOH / g or more and a hydroxyl value of 4 mgKOH / g or more is dissolved in an organic solvent, and a basic compound and water are added and dispersed in the polyester resin solution. A method for producing an aqueous dispersion.
Compound (I): a compound having at least both a carboxyl group and a hydroxyl group in the molecule, wherein the total number of carboxyl groups and hydroxyl groups is 3 or more. Furthermore, the organic solvent and / or a basic compound are removed, The manufacturing method of the polyester resin aqueous dispersion of Claim 8 characterized by the above-mentioned. 9. The organic solvent having a boiling point of 180 ° C. or lower, a solubility in water at 20 ° C. of 5 g / L or more, and an azeotropic point with water of 60 to 150 ° C. is used. Or 9. A method for producing an aqueous polyester resin dispersion according to 9.