JP5687017B2 - Coatings and laminates - Google Patents

Description

The present invention relates to the film having excellent bending resistance.

  Conventionally, polyester resins are widely used in applications such as paints, inks, adhesives, and coating agents as a film-forming resin that dissolves in an organic solvent.

  In recent years, the use of organic solvents has been suppressed for reasons such as environmental protection, dangerous goods regulations by the Fire Service Act, and improvement of the workplace environment, and aqueous polyester resin dispersions in which the polyester resin is finely dispersed in an aqueous medium have come to be used. I came.

  Patent Documents 1 and 2 propose a polyester resin containing an aromatic dicarboxylic acid as an acid component constituting the polyester resin and an alkylene oxide derivative of a bisphenol as an alcohol component. Such a polyester resin has excellent water resistance and solvent resistance, and can improve the properties of the resulting film, but it can be used as a film, sheet, steel plate, rod, or pipe as a final product. When used as a coating, there has been a problem that the film has insufficient bending resistance, such as cracking in the forming process or dropping of the film.

JP 2002-173582 A JP 2008-58467 A

The present invention is resistant aqueous, in addition to the solvent resistance, and to provide a film excellent in flex resistance.

  As a result of intensive studies to solve such problems, the present inventors have found that an aqueous dispersion using a polyester resin having an acid component and an alcohol component having a specific composition can achieve the above object. The present invention has been reached.

That is, the gist of the present invention is as follows.
(1) It is a film formed by removing an aqueous medium from a polyester resin aqueous dispersion, and the polyester resin contained in the polyester resin aqueous dispersion has an acid value of 8 mgKOH / g or more and a glass transition temperature of 40 to 120 ° C. Containing no phthalic acid as an acid component, 95 to 100 mol% terephthalic acid, and 1 to 5 mol% trimellitic acid, and 25 to 80 mol of an alkylene oxide derivative of a bisphenol as an alcohol component %, A film characterized by containing.
(2) The coating according to (1), wherein the alkylene oxide derivative of bisphenol is an ethylene oxide adduct and / or a propylene oxide adduct of 2,2-bis [4- (hydroxyethoxy) phenyl] propane.
(3) The film according to (1) or (2), wherein the number average molecular weight of the polyester resin is 1000 to 30000.
(4) A laminate formed by forming the coating film of (1) to (3).

According to the present invention, resistance to aqueous, in addition to the solvent resistance, it is possible to provide a film excellent in flex resistance.

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 components of the polyester resin in the present invention will be described. The polyester resin used in the present invention is mainly composed of an acid component and an alcohol component.

  The polyester resin in the present invention needs to contain 95-100 mol% of terephthalic acid in the total acid component, preferably 96-100 mol%, more preferably 97-100 mol%. Terephthalic acid can improve the flex resistance of the resin film obtained from the aqueous polyester resin dispersion of the present invention, or the durability and alcohol resistance of the fine particles. When the content of terephthalic acid is less than 95 mol%, the resulting resin film or fine particles have poor processability and alcohol resistance.

  In the present invention, other aromatic dicarboxylic acids that can be used in addition to terephthalic acid include phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 3-tert-butylisophthalic acid, diphenic acid, and the like. . These aromatic dicarboxylic acids can be used alone or in combination of two or more in a range not impairing the properties of the polyester resin. Here, isophthalic acid may decrease the solvent resistance of the resin film or fine particles obtained from the aqueous polyester resin dispersion and should not be used. Moreover, it exists in the tendency which tends to form the glycol component mentioned later, especially neopentyl glycol, and a cyclic oligomer, As a result, a uniform resin film may not be obtained.

  Furthermore, the polyester resin of the present invention needs to contain 1 to 5 mol% of trimellitic acid in the total acid component, more preferably 1 to 4 mol%, more preferably 1 to 3 mol%. More preferably. Trimellitic acid functions as a depolymerization agent for polyester resins, and can lower the molecular weight to an appropriate level and impart an appropriate acid value to the polyester resin. In addition, trimellitic acid has the advantage of adding a large amount of acid value when added in a small amount compared to other depolymerizing agents, for example, isophthalic acid, and the acid value can be imparted without greatly reducing the molecular weight. Therefore, it can be preferably used in the present invention. When the content of trimellitic acid is less than 1 mol%, the acid value imparted to the polyester resin is insufficient, and as a result, even if it is difficult to disperse in an aqueous medium or can be dispersed It is difficult to obtain a uniform aqueous dispersion and the storage stability is poor. When the content of trimellitic acid exceeds 5 mol%, the molecular weight is excessively lowered, and as a result, the resulting resin film or the film forming property of the fine particles is inferior. Inevitably, terephthalic acid is less than 95 mol%, and the flex resistance and alcohol resistance are also inferior.

  In the polyester resin of the present invention, the aromatic dicarboxylic acid component having a sulfonate group in the total acid component is preferably less than 1 mol%, and more preferably 0 mol%. When the aromatic dicarboxylic acid component having a sulfonate group is 1 mol% or more, the water resistance of the resin coating or the fine particles is greatly reduced. In general, by blending an aromatic dicarboxylic acid having a sulfonate group into the composition of the polyester resin, the polyester resin can be easily dispersed in an aqueous medium without using an emulsifier, Such formulations have the disadvantage of significantly impairing water resistance. Therefore, in particular, it is not suitable as a food packaging material accompanied by hot water sterilization or boil sterilization.

  Examples of the aromatic dicarboxylic acid component having a sulfonate group include 5-sodium sulfoisophthalic acid (SIPA-Na), 5-sodium sulfoterephthalic acid (STPA-Na), and 5-potassium sulfoisophthalic acid (SIPA-K). 5-potassium sulfoterephthalic acid (STPA-K), 5-lithium sulfoisophthalic acid (SIPA-Li), 5-lithium sulfoterephthalic acid (STPA-Li), 3,5-di (carbo-β-hydroxyethoxy) Sodium benzenesulfonate (SIPG-Na), 2,5-di (carbo-β-hydroxyethoxy) sodium benzenesulfonate (STPG-Na), potassium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate (SIPG-K), 3,5-di (carbo-β-hydroxy) Toxi) lithium benzenesulfonate (SIPG-Li), dimethyl 5-sodium sulfoisophthalate (SIMM-Na), dimethyl 5-sodium sulfoterephthalate (STPM-Na), dimethyl 5-potassium sulfoisophthalate (SIMM-K) And dimethyl 5-lithium sulfoisophthalate (SIPM-Li).

  In the present invention, the acid component that can be used in addition to the aromatic dicarboxylic acid includes, for example, a saturated aliphatic dicarboxylic acid, an unsaturated aliphatic dicarboxylic acid, an alicyclic dicarboxylic acid, a trifunctional or higher functional carboxylic acid, and the like. And polycarboxylic acids having two or more carboxyl groups. Examples of the saturated aliphatic dicarboxylic acid include oxalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, aicosane diacid, hydrogenated dimer acid, and the like. Examples of the unsaturated aliphatic dicarboxylic acid include fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, dimer acid and the like. Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornenedicarboxylic acid and its anhydride, tetrahydrophthalic acid and its anhydride. Thing etc. are mentioned. Trifunctional or higher carboxylic acids include trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, trimesic acid, ethylene glycol bis (anhydrotrimethyl). And glycerol tris (anhydro trimellitate), 1,2,3,4-butanetetracarboxylic acid, and the like.

  The polyester resin in the present invention needs to contain 25 to 80 mol%, more preferably 25 to 60 mol%, of an alkylene oxide derivative of bisphenols in all alcohol components. Alkylene oxide derivatives of bisphenols can improve the solvent resistance of resin coatings or fine particles obtained from aqueous polyester resin dispersions. When the alkylene oxide derivative of bisphenol is less than 25 mol%, the resulting resin film or fine particles have poor solvent resistance. On the other hand, when the alkylene oxide derivative of the bisphenol exceeds 80 mol%, it is difficult to disperse in an aqueous medium in the production of an aqueous polyester resin dispersion described later. The volume average particle size becomes large and the storage stability is inferior.

  Examples of alkylene oxide derivatives of bisphenols include ethylene oxide adducts (BAEO) of 2,2-bis [4- (hydroxyethoxy) phenyl] propane, and 2,2-bis [4- (hydroxyethoxy) phenyl] propane. Propylene oxide adduct (BAPO), 4,4 ′-(hexafluoroisopropylidene) diphenol ethylene oxide adduct (BAFEO), 4,4 ′-(hexafluoroisopropylidene) diphenol propylene oxide adduct (BAFPO) , Ethylene oxide adduct (BSEO) of bis (4-hydroxyphenyl) sulfone, propylene oxide adduct (BSPO) of bis (4-hydroxyphenyl) sulfone, ethylene oxide adduct of bis (4-hydroxyphenyl) methane ( FEO), 4,4 ′-(m-phenylenediisopropylidene) diphenol ethylene oxide adduct (BMEO), 4,4 ′-(p-phenylenediisopropylidene) diphenol ethylene oxide adduct (BPEO), etc. Can be mentioned. These alkylene oxide derivatives of bisphenols can be used alone or in combination of two or more.

  As the alkylene oxide derivatives of the bisphenols, BAEO and / or BAPO are more preferable. BAEO and BAPO can improve the long-term storage stability of the aqueous dispersion in addition to the effect of improving the solvent resistance of the resulting resin film or fine particles. Moreover, since it is industrially produced in large quantities and can be obtained at low cost, it can be preferably used.

  In the present invention, examples of alcohol components that can be used in addition to the alkylene oxide derivatives of bisphenols 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- Aliphatic glycol components such as butylpropanediol, alicyclic glycol components such as 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol Ether bond-containing glycol component and the like. Further, trifunctional or higher functional alcohol components such as glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol can be used.

  The polyester resin in the present invention may be copolymerized with an aliphatic lactone, hydroxycarboxylic acid, or the like as long as the characteristics of the present invention are not impaired. Examples of the aliphatic lactone include ε-caprolactone, δ-valerolactone, and γ-valerolactone. Examples of the hydroxycarboxylic acid include lactic acid, β-hydroxybutyric acid, p-hydroxybenzoic acid, and an ethylene oxide adduct of 4-hydroxyphenyl stearic acid. The copolymerization amount of the aliphatic lactone or hydroxycarboxylic acid is preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably 1 mol% or less in all the constituent components. .

  Moreover, the monocarboxylic acid and monoalcohol may be copolymerized by the polyester resin in the range which does not impair the characteristic of this invention. The monocarboxylic acid and monoalcohol are each preferably less than 1 mol%, more preferably less than 0.1 mol%, and more preferably 0 mol% of the acid component or alcohol component constituting the polyester resin. It is particularly preferred. When it is 1 mol% or more, at the time of production of a polyester resin described later, extension of molecular chain is inhibited, polycondensation does not proceed, and as a result, a necessary molecular weight may not be obtained, and film forming property may be insufficient.

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

  The acid value of the polyester resin in the present invention needs to be 8 mgKOH / g or more in order to improve the dispersibility and long-term storage stability of the aqueous dispersion. When the acid value of the polyester resin is less than 8 mgKOH / g, it is difficult to disperse in an aqueous medium, and even if it can be dispersed, it is difficult to obtain a uniform aqueous dispersion and storage stability is poor. Specifically, the acid value of the polyester resin is preferably 8 to 40 mgKOH / g, more preferably 8 to 30 mgKOH / g, and still more preferably 8 to 25 mgKOH / g. When it exceeds 40 mgKOH / g, it becomes difficult to increase the number average molecular weight of the polyester resin, and the film forming property tends to be insufficient when a resin film is produced.

  In order to improve the blocking resistance, the glass transition temperature of the polyester resin in the present invention needs to be 40 to 120 ° C, and preferably 50 to 100 ° C. When the glass transition temperature is less than 40 ° C., the blocking resistance is inferior, and when the polyester resin is used as the fine particles, the fine particles are fused with each other and the handling property is lowered. On the other hand, it is difficult to produce a polyester resin having a glass transition temperature exceeding 120 ° C. in the composition of the polyester resin of the present invention.

  The number average molecular weight of the polyester resin in the present invention is preferably 1000 to 30000, more preferably 3000 to 25000, in order to improve the film forming property and workability when a resin film is produced. It is more preferable that it is ˜20000, and it is most preferable that it is 6500-15000. When the number average molecular weight is less than 1000, the film-forming property of the resin film obtained from the aqueous dispersion is inferior. When the number average molecular weight exceeds 30000, the volume average particle size of the polyester resin becomes large, and the long-term storage stability of the aqueous dispersion may be inferior. In addition, dispersity is 1.5-6, Preferably it is 1.5-5, More preferably, it is 2-4. The weight average molecular weight can be calculated by multiplying the number average molecular weight by the degree of dispersion. The dispersity here refers to a value obtained by dividing the weight average molecular weight by the number average molecular weight.

  As a method of controlling the number average molecular weight of the polyester resin, a method of terminating the polymerization with a predetermined viscosity of the polyester melt at the time of polymerization, a polyester resin having a high molecular weight, and then adding a depolymerizing agent to control the molecular weight. And a method of adding a monoalcohol or a monocarboxylic acid. Among them, a method of controlling the molecular weight by adding a depolymerizing agent is preferable.

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

  The polyester resin in this invention can be manufactured by a well-known method combining the said monomer. The method of attaching | subjecting one or more types of the said acid component and one or more types of an alcohol component to a polycondensation reaction by a well-known method is mentioned. 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. Proceeding can include a method of obtaining a polyester resin.

  Specifically, in the esterification reaction, the reaction temperature is preferably 180 to 260 ° C., the reaction time is preferably 2.5 to 10 hours, and 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, tetra-n-butyl titanate, n-butylhydroxy oxotin, can be used. As a usage-amount of a catalyst, it is preferable to set it as 0.1-20 * 10 < ^-4 > mol with respect to 1 mol of acid components.

  Subsequent to the above polycondensation reaction, trimellitic acid and its anhydride can be added to perform a depolymerization reaction in an inert atmosphere. By depolymerizing, a desired acid value can be imparted to the polyester resin.

  Next, the aqueous polyester resin dispersion in 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.

  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. If the content of the polyester resin exceeds 50% by mass, the dispersed polyester resin tends to aggregate and storage stability tends to be poor. When the polyester resin content is less than 5% by mass, when a polyester resin film is formed, a large amount of the polyester resin aqueous dispersion may be consumed in order to obtain a sufficient film thickness.

  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 less than 6, the dispersed polyester resin may be aggregated and a uniform aqueous dispersion may not be obtained.

  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 50 nm and more preferably less than 40 nm in order to improve long-term storage stability. When the volume average particle diameter exceeds 50 nm, it becomes difficult to uniformly disperse the aqueous dispersion, resulting in poor long-term storage stability such as generation of a large amount of sediment.

  The type of water used as the aqueous medium is not particularly limited, and includes distilled water, ion exchange water, city water, industrial water, etc., but from the viewpoint of preventing contamination of impurities, use distilled water or ion exchange water. Is preferred.

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

  The aqueous polyester resin dispersion of the present invention is produced through a dispersion step in which the polyester resin is dispersed in an aqueous medium together with a basic compound. For example, a polyester resin and a basic compound are charged all at once into an aqueous medium, mixed and stirred while raising the temperature. When a basic compound is not used, it becomes difficult for the polyester resin to be dispersed in the aqueous medium. In addition, it is preferable to use an organic solvent for facilitating aqueous formation. However, a part or all of the organic solvent and / or the basic compound can be distilled off by the solvent removal step described later.

  According to the method for producing an aqueous dispersion of the present invention, so-called “self-emulsification” in which dispersion proceeds due to the hydrophilic action of a carboxyl anion generated by neutralizing a carboxyl group of a polyester resin with a basic compound is easy. Achieved. Therefore, it is not necessary to take a so-called phase inversion emulsification in which a polyester resin is dissolved in an organic solvent in advance and this solution is mixed with an aqueous medium containing a basic compound to achieve dispersion. It is advantageous. In addition, when a polyester resin having excellent solvent resistance is used as in the present invention, it may be difficult to dissolve in an organic solvent, but even in such a case, the problem can be solved by using the self-emulsification method. There are often.

  Although the temperature of the reaction tank in a dispersion | distribution process is not specifically limited, The range of 30-100 degreeC is mentioned. Moreover, it is preferable to set according to the glass transition temperature (henceforth Tg) of a polyester resin, and Tg- (Tg + 70) degreeC is mentioned as a preferable range. When the temperature of the reaction vessel reaches a high temperature exceeding 100 ° C., a large amount of energy is consumed for that purpose, and therefore the temperature is preferably 100 ° C. or less. The lower limit of the temperature of the reaction vessel is more preferably Tg + 10 ° C. or more, and the upper limit of the temperature is more preferably 80 to 100 ° C. Specifically, for example, when Tg is 50 ° C, the temperature of the reaction vessel is preferably 50 ° C to 100 ° C, and more preferably 50 to 80 ° C. For example, when Tg is 70 degreeC, 70 to 100 degreeC is preferable and, as for the temperature of a reaction tank, 80 to 100 degreeC is more preferable.

  Examples of the organic solvent that can be used in the present invention include ketone organic solvents, aromatic hydrocarbon organic solvents, ether organic solvents, halogen-containing organic solvents, alcohol organic solvents, ester organic solvents, and glycols. Examples include known organic solvents. Examples of ketone-based organic solvents include methyl ethyl ketone, acetone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, 2-hexanone, 5-methyl-2-hexanone, cyclopentanone, cyclohexanone, and aromatic hydrocarbon-based organic solvents. Examples of the solvent include toluene, xylene, and benzene, and examples of the ether organic solvent include dioxane and tetrahydrofuran. Examples of halogen-containing organic solvents include carbon tetrachloride, trichloromethane, and dichloromethane. Examples of alcohol-based organic solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert- Examples of ester organic solvents such as butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, and 2-methyl-1-butanol include ethyl acetate and acetic acid-n. Examples of glycol organic solvents such as -propyl, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, and methyl propionate 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, and the like diethylene glycol ethyl ether acetate. 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.

  As an organic solvent, the solubility in water at 20 ° C. is preferably 5 g / L or more, and more preferably 10 g / L or more. Moreover, it is preferable that a boiling point is 150 degrees C or less. When the boiling point exceeds 150 ° C., a large amount of energy is wasted to evaporate from the resin film or fine particles by drying. In particular, those having a solubility of 5 g / L or more and a boiling point of 150 ° C. or less are preferred. Specific organic solvents satisfying such conditions include methyl ethyl ketone, tetrahydrofuran, ethanol, n-propanol, isopropanol, and n-butanol. Ethylene glycol monoethyl ether and the like, and those having better dispersibility, dispersion stability, volatility, etc. are preferably alcohols having 2 to 4 carbon atoms, more preferably alcohols having 3 carbon atoms, particularly isopropanol. Illustrated.

  Furthermore, by controlling the content ratio of the organic solvent to be used, an aqueous polyester resin dispersion having a volume average particle size of less than 50 nm can be more easily produced. For example, when isopropanol is used as the organic solvent, the content ratio of isopropanol in the aqueous polyester resin dispersion is more preferably 17 to 27% by mass.

  The basic compound used in the present invention is not particularly limited as long as it can neutralize a carboxyl group, and examples thereof include metal hydroxides, ammonia, and organic amines. Specific examples of the metal hydroxide include LiOH, KOH, NaOH and the like. Specific examples of the organic amine include ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, iminobispropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, diethanolamine, triethanolamine, N, N-diethylethanolamine. N, N-dimethylethanolamine, aminoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like.

  The basic compound in the present invention is preferably a resin having a boiling point of 150 ° C. or less because it is easily volatilized when dried from a resin film or fine particles. Among them, ammonia, diethylamine, triethylamine, in particular, dispersed It is preferable to use triethylamine because it is excellent in stability.

  The amount of the basic compound used is, for example, 0.90 to 3.61 g, preferably 1000 g to 100 g of polyester resin having an acid value of 10 mgKOH / g, from the viewpoint of easy dispersibility, dispersion stability, long-term storage stability, etc. Use about 1.80 to 2.71 g. As a guideline, if the acid value is doubled, it is preferable to double the amount of the basic compound used. If the amount is too large, the liquid viscosity may increase drastically during the dispersion step, making it difficult to easily obtain an aqueous polyester resin dispersion, and if the amount is too small, the polyester resin will be in the aqueous medium. A uniform polyester resin aqueous dispersion cannot be obtained without sufficient dispersion.

  In the method for producing a polyester resin aqueous dispersion of the present invention, an organic solvent or a basic compound may be distilled off (desolvation). The solvent removal step can be performed by a method of distilling the aqueous medium after the dispersion step. Distillation may be carried out at normal pressure or under reduced pressure, and any apparatus can be used as long as it is equipped with a tank into which a liquid can be introduced 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) 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.

  In the polyester resin aqueous dispersion in the present invention, a curing agent, various additives, a compound having a protective colloid action, water, an organic solvent, titanium oxide, zinc white, carbon black and other pigments, dyes, other An aqueous resin such as an aqueous polyester resin, an aqueous urethane resin, an aqueous olefin resin, and an aqueous acrylic resin can be blended and used.

  Examples of the method for forming a resin film in the present invention include a gravure coating method, a Mayer bar coating method, a dipping method, a brush coating method, a spray coating method, a curtain flow coating method, and the like. A uniform resin coating can be formed in close contact with the surfaces of various substrates by uniformly coating the surface and setting it at around room temperature as necessary, followed by heat treatment for drying and baking. 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 the substrate to be coated, but considering the economy, the heating temperature is usually 60 to 250 ° C. 70 to 230 ° C is preferable, and 80 to 200 ° C is most preferable. The heating time is usually 1 second to 30 minutes, preferably 5 seconds to 20 minutes, and most preferably 10 seconds to 10 minutes.

  The thickness of the resin film formed using the aqueous polyester resin 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. Preferably, 0.5 to 20 μm is most preferable.

  As a method for producing the resin fine particles in the present invention, for example, the aqueous dispersion can be obtained by drying and removing the aqueous medium at a temperature lower than the glass transition temperature of the polyester resin. Alternatively, when obtaining particles having a core / shell structure, a prepolymer of a core resin is dispersed in an aqueous dispersion, the prepolymer is polymerized in the aqueous dispersion, and then the aqueous medium is removed. By a known method, particles having a core / shell structure in which the polyester resin fine particles of the present invention are settled as shell particles on the core particles can be obtained.

  Since the aqueous polyester resin dispersion of the present invention is excellent in each characteristic, the resulting resin film or fine particles can be used very suitably. For example, it is very useful as a laminated member for packaging films that perform boil processing, packaging films that perform retort processing, decorative films for high-temperature and high-humidity spaces such as bathrooms, and serves as a shell part of toner particles having a core / shell structure. It is very useful as fine particles.

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

(1) Composition of polyester resin 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 was dissolved in 50 ml of water / 1,4-dioxane = 1/9 (volume ratio) at room temperature, and 0.1N potassium hydroxide methanol solution using cresol red as an indicator. The acid value was defined as the number of mg of potassium hydroxide per 1 g of the copolyester resin consumed for neutralization (mgKOH / g).

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

(4) Number average molecular weight, weight average molecular weight, and degree of dispersion of polyester resin The number average molecular weight, weight average molecular weight, and degree of dispersion in terms of polystyrene were measured using gel permeation chromatography (GPC) under the following conditions.
[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.

(5) Solid content concentration of polyester resin aqueous dispersion About 1 g of the 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

(6) 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).

(7) 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 .

(8) Storage stability of aqueous polyester resin dispersion 30 g of the aqueous 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%)}
A: Less than 0.1% by mass O: Less than 0.5% by mass Δ: Less than 1.0% by mass ×: 1.0% by mass or more

(9) Film-forming property of resin coating The aqueous dispersion is applied to a corona-treated surface of a biaxially stretched PET film (manufactured by Unitika Co., Ltd., 38 μm thick) on a desktop coating apparatus (Yasuda Seiki Co., Ltd., film applicator No. 542). -AB type, equipped with a bar coater), and then dried for 1 minute in a hot air dryer set at 120 ° C. to form a resin film having a thickness of 1 μm. The resin film was visually observed and classified as follows depending on whether or not a resin film without cracks, bumps, or whitening was formed, and the film forming property was evaluated. The film thickness of the film was measured in advance using a thickness meter (manufactured by Union Tool, MICROFINE), and after forming a resin film on the film using an aqueous dispersion, this resin The thickness of the substrate having the coating was measured by the same method, and the difference was taken as the thickness of the resin coating.
○: No cracks, bumps, or whitening is observed ×: Cracks, bumps, or whitening is observed

(10) Resin blocking resistance of resin film In the same manner as in (9) above, after forming a resin film having a film thickness of 1 μm on a PET film, another PET film (thickness 38 μm) was overlaid on the film formation surface. In this state, a load of 500 Pa was applied, left in an atmosphere of 38 ° C. for 24 hours, then cooled to 20 ° C., and using an autograph AG100B manufactured by Shimadzu Corporation, in a constant temperature bath at 20 ° C. with a test speed of 50 mm / min. A 180 degree peel test was conducted, the peeled PET film surface was visually observed, and blocking resistance was determined by the following evaluation.
○: No fusion marks are observed.
X: The adhesion mark is seen or the coating surface is destroyed.

(11) Water resistance of resin coating In the same manner as in (9) above, after forming a resin coating having a thickness of 1 μm on a PET film, it was immersed in distilled water at 25 ° C., gently pulled up after 30 minutes, and air-dried. Then, the appearance of the resin film was visually observed and evaluated according to the following criteria.
○: No change in appearance.
Δ: Although the surface state was changed (the surface became cloudy white, etc.), the resin film did not dissolve or swell.
X: Copolyester resin was dissolved or swollen.

(12) Alcohol 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, it was immersed in isopropyl alcohol at 25 ° C., and gently pulled up after 30 minutes, After air drying, the appearance of the resin coating was visually observed and evaluated according to the following criteria.
○: No change in appearance.
Δ: Although the surface state was changed (the surface became cloudy white, etc.), the resin film did not dissolve or swell.
X: Copolyester resin was dissolved or swollen.

(13) Solvent 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, it was immersed in ethyl acetate at 25 ° C., and gently pulled up after 30 minutes, After air drying, the appearance of the resin coating was visually observed and evaluated according to the following criteria.
○: No change in appearance.
Δ: Although the surface state was changed (the surface became cloudy white, etc.), the resin film did not dissolve or swell.
X: Copolyester resin was dissolved or swollen.

(14) Flexibility of resin coating Using water-based dispersion on tin-free steel (0.3 mm thickness), a desktop coating device (manufactured by Yasuda Seiki Co., Ltd., film applicator No. 542-AB type, equipped with bar coater) After coating, a resin film having a film thickness of 4 μm was formed by drying in a hot air dryer set at 150 ° C. for 3 minutes. The tin-free steel on which the coating was formed was cut out to 150 mm × 50 mm to obtain a test piece. The measurement was performed as follows according to JIS K5600-5-1. Insert the test piece into the coating film performance evaluation device (No. 514 paint film bending tester, manufactured by Yasuda Seiki Co., Ltd.) so that the coating surface is outside the curvature core, and then bend it 180 ° in 1 second. The part was judged visually. Three types of core rods with different diameters were used. Each diameter was 10, 6, 1 mm. The smaller the diameter of the curvature core rod, the more severe the test. The better the severe test, the better the bending resistance.
○: The resin film is not broken or peeled off, and is resistant to bending.
(Triangle | delta): A micro crack is seen in a resin film (crack less than 2 mm).
X: The resin film is cracked and peeled off.

The polyester resin used in Examples and Comparative Examples was obtained as follows.
[Preparation example of polyester resin]
[Polyester resin A]
A mixture of 3323 g of terephthalic acid (TPA), 683 g of ethylene glycol (EG), 1042 g of neopentyl glycol (NPG), and 1,898 g of ethylene oxide adduct (BAEO) of 2,2-bis [4- (hydroxyethoxy) phenyl] propane was autoclaved. The esterification reaction was carried out by heating at 260 ° C. for 6 hours. The charged resin composition was TPA / EG / NPG / BAEO = 100/55/50/30 (molar ratio). Next, 1.6 g of antimony trioxide (2.7 × 10 ⁻⁴ mol per mol of acid component) and 1.0 g of triethyl phosphate (2.7 × 10 ⁻⁴ mol per mol of acid component) were added as catalysts. The system temperature was raised to 280 ° C., and the system pressure was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was continued, and after 6 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when it reached 265 ° C., 147 g of trimellitic acid (0.035 to 1 mol of acid component). Mol) was added and stirred at 265 ° C. for 2 hours to carry out a depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a 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 A.

[Polyester resins BK]
Polyester resins B to K were obtained in the same manner as the polyester resin A except that the charged composition of the polyester resin and the depolymerizing agent were changed as shown in Table 1.

[Polyester resin L]
A mixture of 3323 g of terephthalic acid, 683 g of ethylene glycol, 1042 g of neopentyl glycol and 1,898 g of ethylene oxide adduct of 2,2-bis [4- (hydroxyethoxy) phenyl] propane was heated in an autoclave at 260 ° C. for 6 hours to form an ester. The reaction was carried out. The charged resin composition was TPA / EG / NPG / BAEO = 100/55/50/30 (molar ratio). Next, 1.6 g of antimony trioxide (2.7 × 10 ⁻⁴ mol per mol of acid component) and 1.0 g of triethyl phosphate (2.7 × 10 ⁻⁴ mol per mol of acid component) were added as catalysts. The system temperature was raised to 280 ° C., and the system pressure was gradually reduced to 13 Pa after 1.5 hours. Under these conditions, the polycondensation reaction was continued. After 6 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when the temperature reached 265 ° C., 34 g of trimellitic acid (0.008 per mol of acid component). Mol) was added and stirred at 265 ° C. for 2 hours to carry out a depolymerization reaction. Thereafter, the pressure of the system was gradually reduced to 13 Pa after 30 minutes, and then defoaming was performed for 1 hour. Next, the system was pressurized with nitrogen gas, discharged into a strand, cooled with water, and cut to obtain a polyester resin M in a pellet form (diameter: about 3 mm, length: about 3 mm).

[Polyester resin M]
A mixture of 2824 g of terephthalic acid, 166 g of isophthalic acid, 404 g of sebacic acid (SEA), 683 g of ethylene glycol, 1042 g of neopentyl glycol, and 1898 g of ethylene oxide adduct of 2,2-bis [4- (hydroxyethoxy) phenyl] propane in an autoclave Then, the esterification reaction was carried out by heating at 240 ° C. for 4 hours. The feed composition was TPA / IPA / SEA / EG / NPG / BAEO = 85/5/10/55/50/30 (molar ratio). Next, after adding 2.0 g of tetrabutyl titanate as a catalyst (3.0 × 10 ⁻⁴ mol per mol of acid component), the temperature of the system is raised to 240 ° C., and the pressure of the system is gradually reduced to 1 It was set to 13 Pa after 5 hours. Under these conditions, the polycondensation reaction is continued, and after 5 hours, the system is brought to atmospheric pressure with nitrogen gas, 147 g of trimellitic acid (0.035 mol with respect to 1 mol of acid component) is added, and the mixture is stirred at 240 ° C. for 2 hours. The depolymerization reaction was performed. Thereafter, the system was pressurized with nitrogen gas and the resin was dispensed into a sheet. This was cooled to room temperature to obtain a sheet-like polyester resin N.

  Table 2 shows the final resin compositions and characteristic values of the obtained polyester resins A to M.

[Example 1]
Using a jacketed glass container (contents 2L) that can be sealed and a stirrer (manufactured by Tokyo Science Instruments, Mazela NZ-1200), 300 g of polyester resin A, 250 g of isopropyl alcohol, 11.0 g of triethylamine (1.2 times equivalent to the acid value of the polyester resin), 439 g of distilled water was charged in a glass container, and the jacket was stirred while stirring while maintaining the rotational speed of the stirring blade stirring blade (stirring rod with blades) at 75 rpm. It was heated through hot water. Subsequently, the dispersion temperature was further maintained for 1 hour while maintaining the system temperature at 71 to 75 ° C. Thereafter, cold water was passed through the jacket, and the temperature was lowered to 25 ° C. while stirring at a reduced rotational speed of 30 rpm. The obtained aqueous dispersion was filtered through a 600 mesh stainless steel filter to obtain an aqueous polyester resin dispersion.

[Example 2]
The aqueous dispersion obtained by carrying out the same method as in Example 1 was charged with 900 g in a 2 L flask, further charged with 430 g of distilled water, and distilled under normal pressure to remove the aqueous medium. The solvent removal step was completed when the amount of distillation reached about 430 g, and the mixture was cooled to 25 ° C. The solvent-free aqueous dispersion was filtered through a 600 mesh stainless steel filter to obtain an aqueous polyester resin dispersion.

[Example 3]
The same method as in Example 1 was used except that polyester resin B was used, 14.9 g of triethylamine to be charged (1.2 times equivalent to the acid value of the polyester resin), and distilled water was changed to 435 g. As a result, an aqueous polyester resin dispersion was obtained.

[Example 4]
The same method as in Example 1 was used except that polyester resin C was used, triethylamine to be charged was 11.4 g (1.5 times equivalent to the acid value of the polyester resin), and distilled water was changed to 439 g. As a result, an aqueous polyester resin dispersion was obtained.

[Example 5]
The same method as in Example 1 was used except that polyester resin D was used, and triethylamine to be charged was changed to 11.4 g (1.2 times equivalent to the acid value of the polyester resin) and distilled water was changed to 439 g. As a result, an aqueous polyester resin dispersion was obtained.

[Example 6]
The same method as in Example 1 was used except that polyester resin E was used, 11.9 g of triethylamine to be charged (1.2 times equivalent to the acid value of the polyester resin), and 438 g of distilled water were changed. As a result, an aqueous polyester resin dispersion was obtained.

[Example 7]
The same method as in Example 1 except that the polyester resin F was used, and 8.9 g of triethylamine to be charged (1.5 times equivalent to the acid value of the polyester resin) and 441 g of distilled water were changed. As a result, an aqueous polyester resin dispersion was obtained.

[Comparative Example 1]
The same method as in Example 1 except that the polyester resin G was used, and that triethylamine to be charged was changed to 10.4 g (1.2 times equivalent to the acid value of the polyester resin) and distilled water was changed to 440 g. As a result, an aqueous polyester resin dispersion was obtained.

[Comparative Example 2]
The same method as in Example 1 except that the polyester resin H was used, and that triethylamine to be charged was changed to 11.4 g (1.2 times equivalent to the acid value of the polyester resin) and distilled water was changed to 439 g. As a result, an aqueous polyester resin dispersion was obtained.

[Comparative Example 3]
The same method as in Example 1 was used except that polyester resin I was used, 11.9 g of triethylamine to be charged (1.2 times equivalent to the acid value of the polyester resin), and 438 g of distilled water were changed. As a result, an aqueous polyester resin dispersion was obtained.

[Comparative Example 4]
The same method as in Example 1 was used except that polyester resin J was used, and triethylamine to be charged was changed to 10.5 g (1.5 times equivalent to the acid value of the polyester resin) and distilled water was changed to 439 g. As a result, an aqueous polyester resin dispersion was obtained.

[Comparative Example 5]
The same method as in Example 1 was used except that polyester resin K was used, and that triethylamine to be charged was changed to 12.0 g (1.2 times equivalent to the acid value of the polyester resin) and distilled water was changed to 438 g. As a result, an aqueous polyester resin dispersion was obtained.

[Comparative Example 6]
The same method as in Example 1 except that the polyester resin L was used, and 8.9 g of triethylamine to be charged (1.2 times equivalent to the acid value of the polyester resin) and distilled water were changed to 441 g. As a result, the polyester resin was not dispersed in the aqueous medium, and a uniform aqueous polyester resin dispersion could not be obtained.

[Comparative Example 7]
The same method as in Example 1 was used except that polyester resin M was used, and 9.7 g of triethylamine to be charged (1.2 times equivalent to the acid value of the polyester resin) and distilled water were changed to 440 g. As a result, an aqueous polyester resin dispersion was obtained.

[Reference Example 1]
A polyester resin aqueous dispersion was obtained in the same manner as in Example 1 except that 180 g of isopropyl alcohol and 509 g of distilled water were changed.

[Reference Example 2]
A polyester resin aqueous dispersion was obtained in the same manner as in Example 1 except that 250 g of 1-hexanol was used instead of isopropyl alcohol.

[Reference Example 3]
A polyester resin aqueous dispersion was obtained in the same manner as in Example 1 except that 14.1 g of dibutylamine and 436 g of distilled water were used instead of triethylamine.

  Characteristic evaluation results of polyester resin aqueous dispersions obtained from Examples 1 to 7, Comparative Examples 1 to 7, and Reference Examples 1 to 3, and polyester resin coatings obtained using the aqueous dispersions, Table 3 shows.

  As in Examples 1 to 7, the aqueous polyester resin dispersion of the present invention is not only excellent in long-term storage stability, but the resulting resin film has film-forming properties, water resistance, and alcohol resistance. In addition, the resin film is obtained from an aqueous dispersion, so it is extremely excellent in that it can reduce the burden on the environment. Yes.

  Since the comparative example 1 contained isophthalic acid as a constituent acid component as a constituent acid component, the solvent resistance was insufficient.

  In Comparative Example 2, since terephthalic acid contained as a constituent acid component was less than 95 mol%, the alcohol resistance and the flex resistance were poor.

  In Comparative Example 3, the alkylene oxide derivative of bisphenol contained as a constituent alcohol component was less than 25 mol%, and thus the solvent resistance was poor.

  Since the comparative example 4 exceeded 80 mol% of alkylene oxide derivatives of bisphenols contained as a constituent alcohol component, the storage stability was poor.

  In Comparative Example 5, trimellitic acid contained as a constituent acid component was more than 5 mol% and terephthalic acid was less than 95 mol%, so that the film forming property, flex resistance, and alcohol resistance were poor. Met.

  In Comparative Example 6, trimellitic acid contained as a constituent acid component was less than 1 mol%, and the acid value was less than 8 mgKOH / g, so that the polyester resin could not be dispersed in the aqueous medium.

In Comparative Example 7, since the glass transition temperature was less than 40 ° C., the blocking resistance was poor.

Claims (4)

  It is a film formed by removing an aqueous medium from a polyester resin aqueous dispersion, and the polyester resin contained in the polyester resin aqueous dispersion has an acid value of 8 mgKOH / g or more and a glass transition temperature of 40 to 120 ° C. Does not contain isophthalic acid as a component, contains 95 to 100 mol% terephthalic acid, and 1 to 5 mol% trimellitic acid, and contains 25 to 80 mol% of alkylene oxide derivatives of bisphenols as constituent alcohol components A film characterized by that. The coating according to claim 1, wherein the alkylene oxide derivative of bisphenol is an ethylene oxide adduct and / or a propylene oxide adduct of 2,2-bis [4- (hydroxyethoxy) phenyl] propane. The film according to claim 1 or 2, wherein the number average molecular weight of the polyester resin is 1000 to 30000. The laminated body formed by forming the film in any one of Claims 1-3.