JP4746316B2 - Aqueous polyester resin dispersion and method for producing the same - Google Patents

Description

  The present invention relates to an aqueous polyester resin dispersion that can be applied to various substrates to form a resin film having excellent film performance.

  Polyester resin is a film-forming resin that is excellent in film processability, resistance to organic solvents (solvent resistance), weather resistance, adhesion to various substrates, etc., so it can be used in paints, inks, adhesives, and coating agents. It is widely used as a binder component in such fields.

  In recent years, the use of organic solvents has tended to be restricted from the standpoints of environmental protection, resource conservation, dangerous goods regulations by the Fire Service Act, and workplace environment improvement. A polyester resin aqueous dispersion finely dispersed in an aqueous medium has been actively developed.

  For example, Patent Documents 1 to 4 propose a so-called self-emulsifying type polyester resin aqueous dispersion in which a carboxyl group of a polyester resin is neutralized with a basic compound and dispersed in an aqueous medium. It is described that when a body is used, a film excellent in performance such as processability, water resistance and solvent resistance can be formed.

However, since the polyester resin aqueous dispersions described in these documents use a polyester resin having a small acid value, the amount of carboxy anion produced by neutralization with a basic compound is small. Since the carboxy anion imparts stability to the polyester resin dispersed in the aqueous medium, if the amount of carboxy anion produced is small, the content of the organic solvent contained in the polyester resin aqueous dispersion is low. There is a problem that the polyester resin in the aqueous medium easily aggregates due to external impact.
JP-A-9-296100 JP 2000-26709 A JP 2000-313793 A JP 2002-173582 A

  Under such circumstances, the problem of the present invention is that it contains a low acid value polyester resin and has excellent storage stability and impact stability even when the content of the organic solvent is reduced, and adhesion to a substrate. It is an object of the present invention to provide an aqueous polyester resin dispersion capable of forming a good resin film and a method for producing the same.

The present invention provides a polyester resin aqueous dispersion containing a polyester resin having an acid value of 2 to 10 mgKOH / g and a basic compound and having an organic solvent content of less than 3% by mass, and the pH of the aqueous dispersion is A polyester resin aqueous dispersion characterized by being 8-14.
About.

The present invention also relates to a method for producing the above aqueous polyester resin dispersion, comprising the following steps (1) to (3):
(1) A step of obtaining an aqueous polyester resin dispersion containing a polyester resin having an acid value of 2 to 10 mgKOH / g and a basic compound and having an organic solvent content of 3% by mass or more,
(2) A step of removing the organic solvent from the aqueous polyester resin dispersion obtained in step (1) to obtain an aqueous polyester resin dispersion having an organic solvent content of less than 3% by mass; and (3) step (2) A step of adding a basic compound to the aqueous polyester resin dispersion obtained in (1).

  As a result of diligent research to solve the above problems, the present inventors have controlled the pH of an aqueous dispersion containing a relatively low acid value polyester resin, so that the organic solvent content is low. The present inventors have found that the polyester resin can be stably dispersed in an aqueous medium and the impact stability of the aqueous dispersion is improved, and the present invention has been completed.

  The aqueous polyester resin dispersion of the present invention can form a resin film excellent in film performance such as adhesion to a substrate, processability, water resistance, and solvent resistance. Accordingly, it can be suitably used as a binder component alone or as a binder component by mixing other components as a paint, coating agent or adhesive. Specifically, the polyester resin aqueous dispersion of the present invention is useful for the following applications; polyester films, polyamide films, polyolefin films, and anchor coat agents and adhesiveness-imparting agents for various films such as these deposited films. (Easy adhesion); Anchor coating agent and adhesion-imparting agent (easy adhesion) for various metal plates such as aluminum plate, steel plate and plated steel plate (pre-adhesion); Pre-coated metal paint; Paper coating agent; Textile treatment agent; Paper, metal plate, resin Adhesive for bonding substrates such as sheets; ink binders and the like.

  Moreover, since the polyester resin aqueous dispersion of the present invention is excellent in impact stability, when mixed with other components using a stirrer, various substrates are coated at high speed using a gravure coater, a roll coater or the like. In this case, aggregation of the polyester resin can be suppressed even when the aqueous polyester resin dispersion is impacted, such as when the aqueous polyester resin dispersion vibrates during transportation.

Furthermore, since the content of the organic solvent is reduced, the aqueous polyester resin dispersion of the present invention is useful from the viewpoint of environmental protection, resource saving, and the like.
Thus, the industrial use value of the polyester resin aqueous dispersion of the present invention is extremely high.

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”) contains a polyester resin having a specific acid value and a basic compound in an aqueous medium, and the polyester resin is an aqueous medium. It is a liquid material dispersed in it.

  In the present invention, the polyester resin dispersed in the aqueous medium is originally not dispersed or dissolved in water by itself, and is synthesized from a polybasic acid component and a polyhydric alcohol component.

  The acid value of the polyester resin is 2 to 10 mgKOH / g, preferably 3 to 9 mgKOH / g, and more preferably 4 to 8 mgKOH / g. When the acid value exceeds 10 mgKOH / g, the molecular weight of the polyester resin tends to be small, the processability of the resin film tends to deteriorate, and the water resistance may be insufficient. Moreover, when the acid value is less than 2 mgKOH / g, it tends to be difficult to obtain an aqueous dispersion having good storage stability.

  Further, the polyester resin may contain a hydroxyl group as long as the water resistance of the resin film is not impaired, and the hydroxyl value is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, More preferably, it is 10 mgKOH / g or less.

  The number average molecular weight of the polyester resin is preferably 4,000 or more, more preferably 10,000 or more, and further preferably 15,000 or more. If the number average molecular weight is less than 4,000, the processability of the resin film tends to be insufficient. The upper limit of the number average molecular weight is not particularly limited, but the polyester resin preferably has a number average molecular weight of 50,000 or less from the viewpoint that an aqueous dispersion having good storage stability can be easily obtained.

  The degree of dispersion of the molecular weight distribution of the polyester resin is not particularly limited, but from the viewpoint of further improving the storage stability of the aqueous dispersion, the degree of dispersion of the molecular weight distribution is preferably 8 or less, more preferably 5 or less. Here, the degree of dispersion of the molecular weight distribution is a value obtained by dividing the weight average molecular weight by the number average molecular weight.

  The glass transition temperature of the polyester resin is not particularly limited, but is preferably −50 to 120 ° C., more preferably 0 to 90 ° C., from the viewpoint of further improving the storage stability of the aqueous dispersion.

Next, the components of the polyester resin will be described.
Examples of the polybasic acid component constituting the polyester resin include aromatic polybasic acids, aliphatic polybasic acids, and alicyclic polybasic acids.

  Among the aromatic polybasic acids, examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, naphthalenedicarboxylic acid, and biphenyl dicarboxylic acid. Examples of tribasic or higher aromatic polybasic acids include trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, trimesic acid, ethylene glycol Bis (anhydro trimellitate), glycerol tris (anhydro trimellitate) and the like can be mentioned.

  Among aliphatic polybasic acids, examples of the aliphatic dicarboxylic acid include saturated oxalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, hydrogenated dimer acid, etc. Examples include aliphatic dicarboxylic acids and unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, and dimer acid. Examples of the trifunctional or higher aliphatic polybasic acid include 1,2,3,4-butanetetracarboxylic acid.

  Among the alicyclic polybasic acids, examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornene dicarboxylic acid, and The anhydride, tetrahydrophthalic acid, its anhydride, etc. are mentioned.

  Polybasic acids having a hydrophilic group other than a carboxyl group or a hydroxyl group such as 5-sodium sulfoisophthalic acid can also be used as the polybasic acid, but the water resistance of the resin film formed from the aqueous dispersion is excellent. It is preferable not to use such a polybasic acid because it tends to deteriorate.

  As the polybasic acid component, from the viewpoint of suppressing gelation during the production of the polyester resin, the proportion of the tribasic or higher polybasic acid in the polybasic acid component of the polyester resin is preferably limited to 5 mol% or less.

  Among the polybasic acids described above, an aromatic polybasic acid is preferable, and the ratio of the aromatic polybasic acid in the polybasic acid component of the polyester resin is preferably 50 mol% or more, particularly preferably 50 to 100%, More preferably, it is 60-100 mol%, and it is optimal that it is 70-100 mol%. When the proportion of aromatic polybasic acid is increased, the proportion of aromatic ester bonds that are harder to hydrolyze than aliphatic or alicyclic ester bonds in the resin skeleton increases. However, the decrease in the molecular weight of the polyester resin can be reduced. Further, by increasing the ratio of the aromatic polybasic acid, the hardness, water resistance, solvent resistance, workability, etc. of the resin film formed from the aqueous dispersion are improved.

  As the aromatic polybasic acid, terephthalic acid and isophthalic acid are preferred because they are industrially produced in large quantities and are inexpensive. The total of terephthalic acid and isophthalic acid in the polybasic acid component of the polyester resin is preferable. As a ratio, it is preferable that it is 50-100 mol%, It is more preferable that it is 60-100 mol%, It is optimal that it is 70-100 mol%.

  In particular, the proportion of terephthalic acid in the polybasic acid component of the polyester resin is preferably 30 to 100 mol%, more preferably 50 to 90 mol% or more, and 55 to 75 mol%. Is the best. Increasing the proportion of terephthalic acid tends to improve the hardness, workability, solvent resistance, etc. of the resin coating.

  The polyhydric alcohol component constituting the polyester resin is not particularly limited as long as it is a compound having two or more hydroxyl groups per molecule, and examples thereof include aliphatic glycols having 2 to 10 carbon atoms and fats having 6 to 12 carbon atoms. Examples include cyclic glycols and ether bond-containing glycols.

  Examples of the aliphatic glycol having 2 to 10 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1 , 5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol and the like.

Examples of the alicyclic glycol having 6 to 12 carbon atoms include 1,4-cyclohexanedimethanol.
Examples of the ether bond-containing glycol include diethylene glycol, triethylene glycol, dipropylene glycol, polytetramethylene glycol, polyethylene glycol, and polypropylene glycol. In addition, since the water resistance of a polyester resin, solvent resistance, a weather resistance, etc. may fall when an ether bond increases, the ratio of the ether bond containing glycol to the polyhydric alcohol component of a polyester resin is 10 mol% or less. It is preferable that it is 5 mol% or less.

  In addition, as polyhydric alcohols, bisphenols (such as bisphenol A) such as 2,2-bis [4- (hydroxyethoxy) phenyl] propane, ethylene oxide adducts thereof, and bis [4- (hydroxyethoxy) phenyl] sulfone Such bisphenols (bisphenol S and the like) and ethylene oxide adducts thereof can also be used.

  Furthermore, a polyhydric alcohol having three or more functional groups such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like may be contained as the polyhydric alcohol component, but in order to suppress gelation during the production of the polyester resin. In addition, the proportion of the trifunctional or higher polyhydric alcohol in the polyhydric alcohol component of the polyester resin is preferably limited to 5 mol% or less.

  As the polyhydric alcohol, ethylene glycol and neopentyl glycol are preferably used because they are inexpensive because they are industrially produced in large quantities. The total proportion of ethylene glycol and neopentyl glycol in the polyhydric alcohol component of the polyester resin is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, still more preferably 70 to 100 mol%, and more preferably 80 to 100 mol% is most preferred. In particular, ethylene glycol improves the chemical resistance of the resin film, and neopentyl glycol particularly has the advantage of improving the weather resistance of the resin film. Therefore, it is preferable as the polyhydric alcohol component of the polyester resin.

  The polyester resin may be copolymerized with monocarboxylic acid, monoalcohol, hydroxycarboxylic acid, such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, p-tert-butylbenzoic acid, cyclohexane acid, 4-hydroxyphenyl stearic acid, stearyl alcohol, 2-phenoxyethanol, ε-caprolactone, lactic acid, β-hydroxybutyric acid, p-hydroxyethoxybenzoic acid and the like can be used. These compounds are preferably 4 mol% or less, particularly preferably 2 mol% or less, based on all monomer components constituting the polyester resin.

  In the present invention, the polyester resin can be produced by polycondensing one or more polybasic acid components and one or more polyhydric alcohol components by a known method. For example, all monomer components and / or low polymers thereof are reacted at 180 to 260 ° C. for about 2.5 to 10 hours in an inert atmosphere to carry out an esterification reaction, and subsequently 130 Pa or less in the presence of a polycondensation catalyst. And a method of obtaining a polyester resin by advancing a polycondensation reaction at a temperature of 220 to 280 ° C. until the desired molecular weight is reached.

In the case of imparting a desired acid value or hydroxyl value to the polyester resin, a method of further adding a polybasic acid component or a polyhydric alcohol component following the polycondensation reaction and performing depolymerization under an inert atmosphere, etc. Can be adopted.
In particular, as a method for imparting a desired acid value to the polyester resin, a method in which a polybasic acid anhydride is further added following the polycondensation reaction and an addition reaction with a hydroxyl group of the polyester resin is performed in an inert atmosphere. You can also.

  When the depolymerization and / or addition reaction is performed using a polybasic acid component or a polyhydric alcohol component, the content of the polyester resin constituent component such as an aromatic polybasic acid is used for the depolymerization and / or addition reaction. The ratio regarding the total polybasic acid component or the total polyhydric alcohol component including the polybasic acid component or the polyhydric alcohol component may be within the above-mentioned range. For example, when depolymerization is performed using a polybasic acid component, the proportion of aromatic polybasic acid, the total proportion of terephthalic acid and isophthalic acid, and the proportion of terephthalic acid are the polybasic acid components used for depolymerization. The ratio with respect to all the polybasic acid components containing each should just be in the said range, respectively. Further, for example, in the case where depolymerization is performed using a polyhydric alcohol component, the total ratio of ethylene glycol and neopentyl glycol is within the above-mentioned range with respect to the total polyhydric alcohol components including the polyhydric alcohol component used for depolymerization. If it is in.

  The polyester resin of the present invention is preferably a polyester resin in which a carboxyl group is introduced by the above-described depolymerization and / or addition reaction using a polybasic acid. By introducing a carboxyl group by depolymerization and / or addition reaction, the molecular weight and acid value of the polyester resin can be easily controlled. The polybasic acid used in this case is preferably a tribasic or higher polybasic acid. By using a tribasic or higher polybasic acid, a desired acid value can be imparted while suppressing a decrease in the molecular weight of the polyester resin due to depolymerization. Further, by using a tribasic or higher polybasic acid, although details are unclear, an aqueous dispersion having more excellent storage stability can be obtained.

  Examples of the polybasic acid used in the depolymerization and / or addition reaction include the polybasic acids described in the constituent components of the polyester resin. Among them, an aromatic polybasic acid is preferable, and among the aromatic polybasic acids, Preference is given to terephthalic acid, isophthalic acid, phthalic anhydride, which are aromatic dicarboxylic acids, and trimellitic acid, trimellitic anhydride, which are trifunctional polybasic acids. In particular, when trimellitic anhydride is used, depolymerization and addition reaction are considered to occur in parallel. Therefore, it is possible to give a desired acid value while minimizing molecular weight reduction of the polyester resin due to depolymerization. It is particularly preferred to use trimellitic anhydride because it can.

Next, the aqueous dispersion of the present invention will be described.
The aqueous dispersion of the present invention is a liquid material in which the above-described polyester resin is dispersed in an aqueous medium and a basic compound is contained. The aqueous medium is made of water and may contain an organic solvent. Examples of water include distilled water, ion exchange water, city water, and industrial water.

  The basic compound may be contained in the polyester resin fine particles or in an aqueous medium as long as the pH of the aqueous dispersion described below is achieved. In the present invention, from the viewpoint of further improving the storage stability and impact stability of the aqueous dispersion, the basic compound is preferably contained in both the aqueous medium and the polyester resin. By the basic compound, the carboxyl group of the polyester resin is neutralized to generate a carboxyl anion. Due to the electric repulsive force between the anions, the polyester resin fine particles are not aggregated and stably dispersed. Furthermore, the presence of an excessive amount of the basic compound in the aqueous dispersion, particularly in the aqueous medium, to achieve the pH of the aqueous dispersion described later, prevents the basic compound from coagulating with the polyester resin fine particles. It is thought that it exhibits a buffering action and effectively improves impact stability.

  As the basic compound, inorganic bases such as sodium hydroxide and potassium hydroxide can be used, but organic amines and / or ammonia are preferable from the viewpoint of easy volatilization during resin film formation, and the boiling point is 160 ° C. or less. Some organic amines and / or ammonia are more preferred, and organic amines and / or ammonia having a boiling point of 100 ° C. or less are optimal.

Specific examples of the organic amine include, for example, triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, Ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine , Triethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like.
A basic compound can also be used individually or in combination of 2 or more types.

  The content of the basic compound contained in the aqueous dispersion is not particularly limited as long as the pH of the aqueous dispersion described later is achieved.

  The pH of the aqueous dispersion of the present invention is 8 to 14, preferably 8.5 to 13, and more preferably 9 to 12. When the pH is less than 8, the impact stability of the aqueous dispersion is deteriorated. On the other hand, when the pH exceeds 14, the corrosivity becomes strong, which is not preferable.

  The aqueous dispersion of the present invention may contain an organic solvent. However, the organic dispersion contained in the aqueous dispersion may be damaged by the organic solvent depending on the working environment and the coating material. It is preferable that the solvent is small. In the present invention, the content of the organic solvent with respect to the total amount of the aqueous dispersion is less than 3% by mass, preferably less than 1% by mass, more preferably less than 0.5% by mass, and less than 0.3% by mass. In particular, the content is optimally 0.01% by mass or less. When the content of the organic solvent is 3% by mass or more, not only the working environment is deteriorated, but also the material to be coated is damaged by the organic solvent. Hereinafter, the above range of the organic solvent content achieved by the aqueous dispersion of the present invention is referred to as a range A.

Examples of the organic solvent include known ones such as ketone organic solvents, aromatic hydrocarbon organic solvents, ether organic solvents, halogen-containing organic solvents, alcohol organic solvents, ester organic solvents, glycol-based solvents. An organic solvent etc. are mentioned.
Examples of the ketone organic solvent include methyl ethyl ketone (hereinafter referred to as MEK), acetone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone (hereinafter referred to as MIBK), 2-hexanone, 5-methyl-2-hexanone, 2- Examples include heptanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone and the like.
Examples of the aromatic hydrocarbon organic solvent include toluene, xylene, benzene and the like.
Examples of the ether organic solvent include dioxane, tetrahydrofuran and the like.
Examples of the halogen-containing organic solvent include carbon tetrachloride, trichloromethane, dichloromethane and the like.

Examples of the alcohol organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl. Examples include alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol.
Examples of the ester organic solvent include ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate. , Diethyl carbonate, dimethyl carbonate and the like.
Examples of glycol organic solvents 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. And diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate and the like.
In addition, organic solvents such as 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like are also included.
The organic solvent may be used alone or in combination of two or more.

  Among these organic solvents, those having a solubility in water at 20 ° C. of 5 g / l or more are preferably used, and more preferably 10 g / l or more. When the solubility of the organic solvent in water is less than 5 g / l, the aqueous dispersion may cause phase separation, which is not preferable.

  Moreover, as a boiling point of an organic solvent, 250 degrees C or less is preferable, 150 degrees C or less is more preferable, and 100 degrees C or less is further more preferable. When the boiling point exceeds 250 ° C., it tends to be difficult to volatilize the organic solvent by drying from the resin film.

  From the viewpoint of easy removal of the organic solvent from the aqueous medium, it is preferable to use an organic solvent having a boiling point of 100 ° C. or lower or an organic solvent azeotropic with water. Examples of such organic solvents include methanol, ethanol, n -Propanol, isopropanol, n-butanol, MEK, MIBK, tetrahydrofuran, dioxane, cyclohexanone, ethylene glycol monobutyl ether and the like can be suitably used.

  The water contained in the aqueous dispersion is not particularly limited, and distilled water, ion exchange water, city water, industrial water, and the like can be used, but it is preferable to use distilled water or ion exchange water.

  The volume average particle size of the aqueous dispersion of the present invention, that is, the volume average particle size of the polyester resin dispersed in the aqueous medium containing water is preferably 400 nm or less, more preferably 200 nm or less. 150 nm or less is more preferable, and 100 nm or less is optimal. When the volume average particle diameter exceeds 400 nm, the polyester resin in the obtained aqueous dispersion tends to settle, and storage stability may be impaired.

  The content of the polyester resin contained in the aqueous dispersion of the present invention is preferably 1 to 60% by mass, more preferably 5 to 50% by mass, and further preferably 15 to 40% by mass. . When the content of the polyester resin exceeds 60% by mass, the viscosity of the aqueous dispersion may become very high, and it may be difficult to form a resin film substantially. When the content is less than 1% by mass, it is practical. Not right.

Next, the manufacturing method of the aqueous dispersion of this invention is demonstrated.
The aqueous dispersion of the present invention can be obtained through steps including the following steps (1) to (3).
(1) A step of obtaining an aqueous polyester resin dispersion containing at least the polyester resin (having the acid value described above) and a basic compound and having an organic solvent content of 3% by mass or more;
(2) A step of removing the organic solvent from the aqueous polyester resin dispersion obtained in step (1) to obtain an aqueous polyester resin dispersion in which the organic solvent content is reduced within the range A,
(3) A step of adding a basic compound to the aqueous polyester resin dispersion obtained in the step (2).

The step (1) is a step of obtaining a polyester resin aqueous dispersion having an organic solvent content of 3% by mass or more. As a production method thereof, (a) a polyester resin is dissolved in an organic solvent, and this polyester is used. A method of obtaining a polyester resin aqueous dispersion in which the content of the organic solvent is 3% by mass or more by adding water and a basic compound to the resin solution, (b) polyester resin, basic compound, organic solvent, and water in a lump A method of obtaining an aqueous polyester resin dispersion having an organic solvent content of 3% by mass or more by charging in a container and heating the system while stirring is mentioned.
In the present invention, the production method (a) is preferred because an aqueous dispersion can be easily obtained.

  The production method (a) substantially comprises two steps, a dissolution step and a phase inversion emulsification step. The dissolution step is a step of dissolving the polyester resin in an organic solvent, and the phase inversion emulsification step is a step of dispersing the polyester resin dissolved in the organic solvent in water together with the basic compound.

First, in the dissolving step, the polyester resin is dissolved in an organic solvent. At this time, the concentration of the polyester resin in the obtained solution is preferably in the range of 10 to 70% by mass, more preferably in the range of 20 to 60% by mass, and particularly preferably in the range of 30 to 50% by mass. When the concentration of the polyester resin in the solution exceeds 70% by mass, in the next phase inversion emulsification step, the viscosity increases greatly when mixed with water, and the aqueous dispersion obtained from such a state is The volume average particle size tends to be large, which is not preferable in terms of storage stability. When the concentration of the polyester resin is less than 10% by mass, the concentration of the polyester resin is further lowered by the next phase inversion emulsification step, or a large amount of organic solvent is removed in the step (2) described later. It is uneconomical. An apparatus for dissolving the polyester resin in the organic solvent is not particularly limited as long as it includes a tank into which a liquid can be charged and can be appropriately stirred. Moreover, when the polyester resin is difficult to dissolve, it may be heated.
In addition, the polyester resin used at a melt | dissolution process may be individual, or may mix and use 2 or more types.

  As the organic solvent, those described above can be used singly or in combination of two or more. In order to obtain the aqueous dispersion of the present invention, the polyester resin can be dissolved by 10% by mass or more. It is preferable to select an organic solvent. Examples of such organic solvents include acetone, MEK, MIBK, dioxane, tetrahydrofuran, cyclohexanone alone, acetone / ethylene glycol monobutyl ether mixed solution, MEK / ethylene glycol monobutyl ether mixed solution, MIBK / ethylene glycol monobutyl ether mixed solution, dioxane. / Ethylene glycol monobutyl ether mixed solution, tetrahydrofuran / ethylene glycol monobutyl ether mixed solution, cyclohexanone / ethylene glycol monobutyl ether mixed solution, acetone / isopropanol mixed solution, MEK / isopropanol mixed solution, MIBK / isopropanol mixed solution, dioxane / isopropanol mixed solution, Tetrahydrofuran / isopropanol mixed solution, cyclohexane Non / isopropanol mixture solution or the like can be suitably used.

Next, the phase inversion emulsification process will be described.
In the phase inversion emulsification step, the polyester resin solution obtained in the dissolution step is mixed with water and a basic compound to perform phase inversion emulsification. In the present invention, it is preferable that the basic compound is added to the polyester resin solution in advance, and water is gradually added thereto for phase inversion emulsification. This is because the basic compound contributes to the improvement of storage stability more effectively. When the rate of water addition is high, a lump of polyester resin is formed, and this lump tends to be difficult to disperse in an aqueous medium, so that the yield of the finally obtained aqueous dispersion becomes poor and economical. is not.

  In the present invention, “phase inversion emulsification” means that an amount (mass) of water exceeding the amount (mass) of organic solvent contained in this solution is added to an organic solvent solution of the polyester resin, and the polyester resin solution is added to the aqueous phase. It means that oily phase particles made of are dispersed.

  The phase inversion emulsification step is preferably performed at 40 ° C or lower, more preferably performed at 30 ° C or lower, further preferably performed at 20 ° C or lower, and particularly preferably performed at 15 ° C or lower. By performing the phase inversion emulsification step at 40 ° C. or lower, the aqueous dispersion obtained has a small volume average particle size, and an aqueous dispersion having excellent storage stability can be obtained. In addition, in the step (2) described later, it is possible to suppress the formation of precipitation of the polyester resin caused by aggregation of the polyester resin dispersed in the aqueous medium. It is.

  The apparatus for performing the phase inversion emulsification step is not particularly limited as long as it has a tank into which a liquid can be charged and can be appropriately stirred. Examples of such an apparatus include apparatuses widely known to those skilled in the art as solid-liquid stirring apparatuses and emulsifiers (for example, homomixers). When using a high shearing emulsifier such as a homomixer, the liquid temperature may rise due to shear heat, so it is preferable to use it while cooling. The phase inversion emulsification step may be performed under normal pressure, reduced pressure, or increased pressure.

Next, the manufacturing method of (b) is demonstrated.
An apparatus is provided that is equipped with a tank into which a liquid can be charged and that can appropriately stir a mixture of an aqueous medium and a polyester resin powder or granular material charged into the tank. As such a device, a device widely known to those skilled in the art as a solid-liquid stirring device or an emulsifier can be used. Usually, a simple lid is provided and used under normal pressure or slight pressure. However, an apparatus capable of pressurization of 0.1 MPa or more can be used as necessary.

  An aqueous medium composed of water, a basic compound and an organic solvent, and a granular or powdered polyester resin are put into a tank of this apparatus, and are preferably coarsely dispersed by stirring and mixing at a temperature of 40 ° C. or lower. At this time, when the shape of the polyester resin is a sheet or a large lump that is difficult to coarsely disperse, it may be shifted to a heating step described later. Next, the temperature in the tank is preferably 45 ° C. or higher, more preferably (Tg-20) ° C. or higher of the polyester resin, further preferably (Tg-10) ° C. or higher of the polyester resin, preferably 15 to The polyester resin aqueous dispersion in which the content of the organic solvent is 3% by mass or more is obtained by sufficiently agitating the polyester resin by continuing stirring for 120 minutes, and then preferably cooling to 40 ° C. or lower with stirring. Obtainable. As a heating method in the tank, heating from the outside of the tank is preferable. For example, an oil bath or a water bath is used for external heating, or a tank is provided with a jacket, and the oil or water heated in the jacket is used. A method of externally heating the inside of the tank can be exemplified by flowing the water.

Examples of the cooling method in the tank include a method of naturally cooling at room temperature and a method of cooling using 0 to 40 ° C. oil or water in the heating method.
In addition, it is preferable to perform cooling, stirring the obtained polyester resin aqueous dispersion. Cooling without stirring is not preferable because a polyester resin film may be formed on the liquid surface (surface in contact with air).

Next, the process (2) will be described.
The step (2) is a step of removing the organic solvent from the aqueous polyester resin dispersion obtained in the step (1) to obtain an aqueous polyester resin dispersion in which the organic solvent content is reduced within the range A. It is.

  The removal of the organic solvent can be performed by distillation, and the distillation can be performed under reduced pressure or normal pressure. In some cases, agglomerates are likely to be generated when distilled under normal pressure. In such a case, distillation is performed under reduced pressure, and the internal temperature is 70 ° C. or lower, preferably 60 ° C. or lower, more preferably 50 ° C. or lower. It is good to adjust as follows. As an apparatus for carrying out the distillation, any apparatus can be used as long as it has a tank into which a liquid can be introduced and can be appropriately stirred. Although depending on the type of basic compound, most types of basic compounds, particularly organic amines and ammonia, are at least partially removed by distillation.

  When distillation is performed, water is also removed, and the content of the polyester resin in the aqueous dispersion increases. Therefore, after the distillation, water is added to the aqueous dispersion to achieve a desired polyester resin content. The organic solvent content of the aqueous dispersion at this time may be in the range A.

  The desired organic solvent content can usually be achieved with only one treatment consisting of distillation and addition of water as described above, but if not, it can be achieved by repeatedly performing such treatment. What is necessary is just to achieve the organic solvent content rate.

  The polyester resin content and the organic solvent content achieved in this step are almost the same even after the subsequent step (3).

Next, the step (3) will be described.
Step (3) is a step of adding a basic compound to the aqueous polyester resin dispersion obtained in step (2).
By adding the basic compound, the pH of the aqueous polyester resin dispersion obtained in the step (2) is adjusted within the pH range specified in the present invention. If the basic compound is not added in this step, the pH specified in the present invention cannot be achieved. This is because even if a relatively large amount of the basic compound is used in the step (1), the basic compound is removed together with the organic solvent in the step (2). For example, even if triethylamine is used in the method (a) in the step (1) in an amount of 23.3 mass% with respect to the polyester resin, the pH of the aqueous dispersion obtained in the step (2) is about 7.2. Yes, the aqueous dispersion pH defined in the present invention cannot be achieved. Further, for example, even when ammonia water (concentration: 28% by mass) is used in an amount of 2.5% by mass with respect to the polyester resin in the method (a) in the step (1), the aqueous dispersion obtained in the step (2) is obtained. The pH of the body is about 7.1, and the aqueous dispersion pH defined in the present invention cannot be achieved. Further, for example, even if N, N-dimethylethanolamine is used in an amount of 1.25% by mass with respect to the polyester resin in the method (a) in the step (1), the aqueous dispersion obtained in the step (2) The pH is about 7.5, and the aqueous dispersion pH defined in the present invention cannot be achieved.

  When the basic compound is added rapidly, the aqueous polyester resin dispersion obtained in the step (2) may be aggregated. Therefore, it is preferable to slowly add the basic compound while stirring the aqueous dispersion. . The basic compound can be added after diluting in advance with water or the above-mentioned organic solvent or a mixture thereof. The amount of the organic solvent used is in such a range that the organic solvent content in the obtained aqueous dispersion falls within the above range A.

As the basic compound used in the step (3), those described above can be used, and organic amines and / or ammonia are preferable from the viewpoint of being easily volatilized during the formation of the resin film, and the boiling point is 160 ° C. or lower. And / or ammonia is more preferred, with organic amines and / or ammonia having a boiling point of 100 ° C. or less being optimal. The basic compound used in the step (1) and the step (3) may be the same or different.
The most preferable combination of the basic compounds in the step (1) and the step (3) is (1) step: triethylamine- (3) step: triethylamine or ammonia, (1) step: ammonia- (3 Step): Triethylamine or ammonia.

  By such a production method, the aqueous dispersion of the present invention has a uniform state in which a portion where the solid content concentration is locally different from other portions such as precipitation and phase separation is not found in the aqueous medium. can get.

  In producing the aqueous dispersion of the present invention, a filtration step may be provided in the process for the purpose of removing foreign substances and the like. In such a case, for example, a stainless steel filter of about 300 mesh (wire diameter 0.035 mm, plain weave) may be installed and pressure filtration (air pressure 0.2 MPa) may be performed.

Next, a method for using the aqueous dispersion of the present invention will be described.
Since the aqueous dispersion of the present invention is excellent in film forming ability, it is uniformly coated on the surface of various substrates by a known film forming method such as dipping method, brush coating method, spray coating method, curtain flow coating method and the like. Then, after setting it at around room temperature as necessary, it is subjected to a heat treatment for drying and baking, whereby a uniform resin film can be formed in close contact with the surfaces of various substrates. 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, etc., but considering the economy, the heating temperature is preferably 60 to 250 ° C., 70 -230 degreeC is more preferable, and 80-200 degreeC is especially preferable. The heating time is preferably 1 second to 30 minutes, more preferably 5 seconds to 20 minutes, and particularly 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 preferably 0.01 to 40 μm, more preferably 0.1 to 30 μm, 0.5-20 micrometers is especially preferable.

  In the aqueous dispersion of the present invention, a curing agent, a surfactant, a compound having a protective colloid effect, a water-soluble polymer, water, an organic solvent, titanium oxide, zinc white, carbon black, etc. Dyes; Other water-based polyester resins, water-based urethane resins, water-based olefin resins, water-based acrylic resins and other water-based resins; repellency inhibitors; leveling agents; antifoaming agents; anti-waxing agents; rheology control agents; An ultraviolet absorber; a lubricant; other additives can be blended. Among the above additives, a surfactant, a compound having a protective colloid action, a water-soluble polymer, and the like may be added after the step (2) and before the step (3).

  The curing agent is not particularly limited as long as it is a functional group possessed by a polyester resin, for example, a curing group having reactivity with a carboxyl group or its anhydride and hydroxyl group, such as urea resin, melamine resin, benzoguanamine resin, etc. Examples include amino resins, polyfunctional epoxy compounds, polyfunctional isocyanate compounds and their various blocked isocyanate compounds, polyfunctional aziridine compounds, carbodiimide group-containing compounds, oxazoline group-containing polymers, phenol resins, etc. Or you may use 2 or more types together.

  Examples of compounds having protective colloidal action include vinyl monomers containing polyvinyl alcohol, polyethylene oxide, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, modified starch, polyvinylpyrrolidone, polyacrylic acid, acrylic acid and / or methacrylic acid as one component. Examples thereof include a polymer, polyitaconic acid, gelatin, gum arabic, casein, and swellable mica.

Examples of water include distilled water, ion exchange water, city water, and industrial water.
Examples of the organic solvent include the organic solvents described above.

  Examples of the surfactant include all surfactants such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Examples of the nonionic surfactant include alkylene oxide adducts of alkylphenols such as nonylphenol and octylphenol, and alkylene oxide adducts of higher alcohols. Examples of such nonionic surfactants include Algerich Igepal series, Sanyo Kasei Naroacty N-100, Naroacty N-120, Naroacty N-140 and other Naroacty series, Sannonic SS-120. Sannonic SS series such as Sannonic SS-90, Sannonic SS-70, Sannonic FD-140, Sannonic FD series such as Sannonic FD-100, Sannonic FD-80, Cedran FF-220, Cedran FF-210, Cedran FF-200 , Cedran FF series such as Cedran FF-180, Cedran SNP series such as Cedran SNP-112, New Paul PE series such as New Pole PE-64, New Pole PE-74, New Pole PE75, etc. Morin 11, and the like.

The present invention will be specifically described below with reference to examples.
(1) Composition of polyester resin
^It calculated | required from < ¹ > H-NMR analysis (The product made by a Varian, 300MHz). 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 / dioxane = 1/9 (volume ratio), titrated with KOH using cresol red as an indicator, and the amount of KOH consumed for neutralization. A value obtained by converting the number of mg per 1 g of the polyester resin was determined as an acid value.

(3) Hydroxyl value of polyester resin 3 g of polyester resin is precisely weighed, added with 0.6 ml of acetic anhydride and 50 ml of pyridine, stirred at room temperature for 48 hours, and then reacted with 5 ml of distilled water. By further stirring for 6 hours at room temperature, all acetic anhydride that was not used in the reaction was changed to acetic acid. Add 50 ml of dioxane to this solution, titrate with KOH using cresol red / thymol blue as an indicator, and the amount of KOH consumed for neutralization (W ₁ ) and the amount of acetic anhydride initially charged with the polyester resin. From the amount of KOH required for neutralization (calculated value: W ₀ ) when acetic acid is completely used without reaction, the difference (W ₀ -W ₁ ) is obtained in mg of KOH, and this is calculated. The value divided by the number of grams of the polyester resin was taken as the hydroxyl value.

(4) Number average molecular weight of polyester resin The number average molecular weight is determined by GPC analysis (liquid feeding unit LC-10ADvp type and UV-visible spectrophotometer SPD-6AV type manufactured by Shimadzu Corporation), detection wavelength: 254 nm, solvent: tetrahydrofuran , Polystyrene conversion). In addition, by this GPC analysis, the weight average molecular weight of a polyester resin can also be calculated | required and the dispersion degree of molecular weight distribution can be calculated | required as a value which remove | divided the weight average molecular weight by the number average molecular weight.

(5) Glass transition temperature of the polyester resin 10 mg of the polyester resin was used as a sample, and measurement was performed using a DSC (Differential Scanning Calorimetry) apparatus (DSC7 manufactured by PerkinElmer Co., Ltd.) at a temperature rising rate of 10 ° C./min. An intermediate value of two bending point temperatures derived from the glass transition in the temperature rising curve was determined, and this was taken as the glass transition temperature (Tg).

(6) Solid Content Concentration of Aqueous Dispersion About 1 g of the aqueous dispersion was weighed (Xg), and the mass of the residue (solid content) after drying at 150 ° C. for 2 hours was weighed (Yg) ), And the solid content concentration was determined by the following formula.
Solid content concentration (% by mass) = Y × 100 / X

(7) Content of organic solvent in aqueous dispersion Shimadzu Corporation gas chromatograph GC-8A [using FID detector, carrier gas: nitrogen, column packing material (manufactured by GL Sciences): PEG-HT (5% ) -UNIPORT HP (60/80 mesh), column size: diameter 3 mm × 3 m, sample charging temperature (injection temperature): 150 ° C., column temperature: 60 ° C., internal standard substance: n-butanol], aqueous dispersion Was diluted with water directly into the apparatus, and the content of the organic solvent was determined. The detection limit was 0.01% by mass.

(8) Storage stability of aqueous dispersion 30 ml of the aqueous dispersion was placed in a 50 ml glass sample bottle, and the appearance change after standing and storing at 25 ° C. for 60 days was visually observed. The storage stability of the aqueous dispersion was evaluated on the basis.
○: No change in appearance.
X: Phase separation and precipitation are observed.

(9) Volume average particle diameter of aqueous dispersion The aqueous dispersion was diluted to 0.1% with water, and the volume average particle diameter was measured using MICROTRAC UPA (model 9340-UPA) manufactured by Nikkiso.

(10) Thickness of resin film After measuring the thickness of the base material in advance using a thickness meter (manufactured by Union Tool, MICROFINE Σ), and forming the resin film on the base material using an aqueous dispersion The thickness of the substrate having this resin film was measured by the same method, and the difference was taken as the thickness of the resin film.

(11) Adhesion of resin coating Using a tabletop coating device (manufactured by Yasuda Seiki, film applicator No. 542-AB, equipped with a bar coater), an aqueous aqueous dispersion is coated on the substrate and set to 130 ° C. By heating in the oven for 1 minute, a resin film having a thickness of about 1 μm is formed on the substrate, and then the end of the adhesive tape (width 18 mm) defined in JIS Z1522 is left on the resin film. After adhering and rubbing with an eraser, 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 (using a Perkin-Elmer SYSTEM2000, Ge60 ° 50 × 20 × 2 mm prism), it is determined whether or not a resin film is attached to the adhesive tape surface. And the adhesion of the resin film to the substrate was evaluated according to the following criteria. A biaxially stretched PET film (manufactured by Unitika Ltd., thickness 12 μm) was used as the substrate.
○: No peak derived from the resin film is observed on the adhesive tape surface.
X: A peak derived from the resin film is observed on the adhesive tape surface.

(12) pH of aqueous dispersion
Using a commercially available pH meter (Horiba Ltd., pH METER F-21), the pH of the aqueous dispersion was measured at 24 ± 1 ° C., and this value was defined as the pH in the present invention.
In addition, before measuring the pH of the aqueous dispersion, the pH meter was prepared by using a neutral phosphate standard buffer (pH of 6.86 ± 0.02 at 25 ° C.) and a borate standard buffer (25 ° C. Calibration was carried out at a pH of 9.18 ± 0.02).

(13) Impact Stability of Aqueous Dispersion About 400 g of the aqueous dispersion is filled in a polyethylene container of 500 ml, and a commercially available paint shaker (manufactured by Asada Tekko Co., No. PC1290) is used for 30 minutes under an atmosphere of 25 ° C. I was shocked. Thereafter, the aqueous dispersion was filtered through a 250 mesh (mesh 0.071 mm) stainless steel filter, and the solid content concentration of the filtrate was measured.

  B / A is calculated from A and B, assuming that the solid content concentration before impact is A (mass%) and the solid content concentration after impact is B (mass%), and this is an index of impact stability. It was. In addition, it is excellent in impact stability, so that B / A is large. B / A of 0.80 or more is a practically acceptable range, and the range of 0.90 to 1.00, particularly 0.95 to 1.00, is comfortable without the user having to worry about precipitation. It is a range that can be used.

The polyester resin used in Examples and Comparative Examples was obtained as follows.
[Polyester resin P-1]
A mixture of 2492 g of terephthalic acid, 415 g of isophthalic acid, 1516 g of sebacic acid, 1210 g of ethylene glycol, and 1484 g of neopentyl glycol was heated in an autoclave at 250 ° C. for 4 hours to carry out an esterification reaction. Subsequently, after adding 3.3 g of zinc acetate dihydrate as a catalyst, the temperature of the system was raised to 270 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction is continued for another 4 hours, the system is brought to atmospheric pressure with nitrogen gas, the temperature of the system is lowered, and when the temperature reaches 265 ° C., 29 g of trimellitic anhydride is added and stirred at 265 ° C. for 2 hours. The depolymerization reaction was performed. Thereafter, the system was put under pressure with nitrogen gas, and the resin was dispensed in a sheet form. After cooling at room temperature, a sheet-like polyester resin P-1 was obtained.

[Polyester resin P-2]
A mixture of 2492 g of terephthalic acid, 415 g of isophthalic acid, 1516 g of sebacic acid, 1210 g of ethylene glycol, and 1484 g of neopentyl glycol was heated in an autoclave at 250 ° C. for 4 hours to carry out an esterification reaction. Subsequently, after adding 3.3 g of zinc acetate dihydrate as a catalyst, the temperature of the system was raised to 270 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction is continued for another 4 hours, the system is brought to atmospheric pressure with nitrogen gas, the temperature of the system is lowered, and when it reaches 265 ° C., 58 g of trimellitic anhydride is added and stirred at 265 ° C. for 2 hours. The depolymerization reaction was performed. Thereafter, the system was put into a pressurized state with nitrogen gas, and the resin was dispensed into a sheet shape. After cooling at room temperature, a sheet-shaped polyester resin P-2 was obtained.

[Polyester resin P-3]
A mixture comprising 2907 g of terephthalic acid, 1246 g of isophthalic acid, 1133 g of ethylene glycol and 1614 g of neopentyl glycol was heated in an autoclave at 260 ° C. for 4 hours to carry out an esterification reaction. Then, 1.8 g of antimony triacid was added as a catalyst, the temperature of the system was raised to 280 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was continued, and after 4 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when the temperature reached 250 ° C., 53 g of trimellitic acid was added and stirred at 250 ° C. for 2 hours. The depolymerization reaction was performed. Thereafter, the pressure of the system was gradually reduced to 13 Pa after 0.5 hours, and then defoaming was performed for 1 hour. Next, the system was pressurized with nitrogen gas, the resin was discharged in a strand shape, cooled with water, and cut to obtain a polyester resin P-3 in a pellet form (diameter: about 3 mm, length: about 3 mm).

  Table 1 shows the results of analyzing or evaluating the characteristic values of the polyester resin obtained as described above.

<Example 1>
Step (1) [Dissolution step] 400 g of polyester resin P-1 and 600 g of MEK are put into a 3 L polyethylene container, and the stirrer (Mazela 1000, manufactured by Tokyo Rika Co., Ltd.) is heated while heating the container with hot water of about 60 ° C. ) Was completely dissolved in MEK to obtain a polyester resin solution having a solid content concentration of 40% by mass.
[Phase inversion emulsification step] Next, 500 g of the above polyester resin solution was charged into a jacketed glass container (internal volume 2 L), and cold water was passed through the jacket to maintain the system temperature at 13 ° C, with a stirrer (manufactured by Tokyo Rika Co., Ltd., MAZELA1000). Stirring was performed (rotation speed: 600 rpm). Next, 23.3 g of triethylamine was added as a basic compound while stirring, and 476.7 g of distilled water at 13 ° C. was subsequently added at a rate of 100 g / min. During addition of the whole amount of distilled water, the system temperature was always 15 ° C. or lower. After completion of the addition of distilled water, the mixture was stirred for 30 minutes to obtain a polyester resin aqueous dispersion having a solid content concentration of 20% by mass and an organic solvent content of 3% by mass or more.

(2) Step 800 g of the polyester resin aqueous dispersion obtained in the step (1) and 52.3 g of distilled water were placed in a 2 L flask, and the organic solvent was removed by distillation at normal pressure. Distillation was terminated when the amount of distillation reached about 360 g, and after cooling to room temperature, it was filtered through a 250 mesh (opening 0.071 mm) stainless steel filter. Subsequently, after measuring the solid content concentration of this aqueous dispersion, distilled water was added so that the solid content concentration was 30% by mass. The aqueous polyester resin dispersion thus obtained had a solid content concentration of 30.3% by mass and a pH of 6.6. The content of the organic solvent was 0.01% by mass or less.

Step (3) While stirring 500 g of the polyester resin aqueous dispersion obtained in the step (2), 2.6 g of triethylamine was added to obtain the aqueous dispersion of the present invention.
The solid content concentration of this aqueous dispersion was 30.1% by mass, and the pH was 10.8.

<Example 2>
In the step (3) of Example 1, an aqueous dispersion of the present invention was obtained in the same manner as in Example 1 except that 0.5 g of 28% by mass of ammonia water was added instead of triethylamine. The content of the organic solvent in the aqueous dispersion obtained in the step (2) of this example was 0.01% by mass or less.

< Reference Example 1 >
Step (1) [Dissolution step] 400 g of polyester resin P-1 and 600 g of MEK are put into a 3 L polyethylene container, and the stirrer (Mazela 1000, manufactured by Tokyo Rika Co., Ltd.) is heated while heating the container with hot water of about 60 ° C. ) Was completely dissolved in MEK to obtain a polyester resin solution having a solid content concentration of 40% by mass.
[Phase inversion emulsification step] Next, 500 g of the above polyester resin solution was charged into a jacketed glass container (internal volume 2 L), and cold water was passed through the jacket to maintain the system temperature at 13 ° C, with a stirrer (manufactured by Tokyo Rika Co., Ltd., MAZELA1000). Stirring was performed (rotation speed: 600 rpm). Next, 23.3 g of triethylamine was added as a basic compound while stirring, and 476.7 g of distilled water at 13 ° C. was subsequently added at a rate of 100 g / min. During addition of the whole amount of distilled water, the system temperature was always 15 ° C. or lower. After completion of the addition of distilled water, the mixture was stirred for 30 minutes to obtain a polyester resin aqueous dispersion having a solid content concentration of 20% by mass and an organic solvent content of 3% by mass or more.

Step (2) 800 g of the polyester resin aqueous dispersion obtained in step (1) was placed in a 2 L flask and distilled at normal pressure to remove the organic solvent. Distillation was terminated when the amount of distillate reached about 280 g, and after cooling to room temperature, it was filtered with a 250 mesh (aperture 0.071 mm) stainless steel filter. Subsequently, after measuring the solid content concentration of this aqueous dispersion, distilled water was added so that the solid content concentration was 30% by mass. The aqueous polyester resin dispersion thus obtained had a solid content concentration of 30.0% by mass and a pH of 7.3. The content of the organic solvent was 2.9% by mass.

Step (3) While stirring 500 g of the polyester resin aqueous dispersion obtained in the step (2), 1.6 g of 28% by mass of ammonia water was added to obtain an aqueous dispersion of the present invention.
The solid content concentration of this aqueous dispersion was 29.9% by mass, and the pH was 10.2. Moreover, the content rate of the organic solvent was 2.9 mass%.

< Reference Example 2 >
Step (1) [Dissolution step] 400 g of polyester resin P-2 and 600 g of MEK are put into a 3 L polyethylene container, and the stirrer (Mazela 1000, manufactured by Tokyo Rika Co., Ltd.) is heated while heating the container with hot water of about 60 ° C. ) Was completely dissolved in MEK to obtain a polyester resin solution having a solid content concentration of 40% by mass.
[Phase inversion emulsification step] Next, 500 g of the above polyester resin solution was charged into a jacketed glass container (internal volume 2 L), and cold water was passed through the jacket to maintain the system temperature at 13 ° C, with a stirrer (manufactured by Tokyo Rika Co., Ltd., MAZELA1000). Stirring was performed (rotation speed: 600 rpm). Next, 2.5 g of 28% by mass of ammonia water was added as a basic compound while stirring, and then 497.5 g of 13 ° C. distilled water was added at a rate of 100 g / min. During addition of the whole amount of distilled water, the system temperature was always 15 ° C. or lower. After completion of the addition of distilled water, the mixture was stirred for 30 minutes to obtain a polyester resin aqueous dispersion having a solid content concentration of 20% by mass and an organic solvent content of 3% by mass or more.

(2) Step 800 g of the polyester resin aqueous dispersion obtained in the step (1) and 52.3 g of distilled water were placed in a 2 L flask, and the organic solvent was removed by distillation at normal pressure. Distillation was terminated when the amount of distillation reached about 360 g, and after cooling to room temperature, it was filtered through a 250 mesh (opening 0.071 mm) stainless steel filter. Subsequently, after measuring the solid content concentration of this aqueous dispersion, distilled water was added so that the solid content concentration was 30% by mass. The aqueous polyester resin dispersion thus obtained had a solid content concentration of 30.2% by mass and a pH of 6.8. The content of the organic solvent was 0.01% by mass or less.

Step (3) While stirring 500 g of the polyester resin aqueous dispersion obtained in the step (2), 2.6 g of triethylamine was added to obtain the aqueous dispersion of the present invention.
The solid content concentration of this aqueous dispersion was 30.0% by mass, and the pH was 10.5.

< Reference Example 3 >
In the step (3) of Reference Example 2 , an aqueous dispersion of the present invention was obtained in the same manner as Reference Example 2 , except that 0.4 g of 28% by mass of ammonia water was added instead of triethylamine. The content of the organic solvent in the aqueous dispersion obtained in the step (2) of this example was 0.01% by mass or less.

<Example 3 >
Step (1) [Dissolution step] 400 g of polyester resin P-3 and 600 g of MEK are put into a 3 L polyethylene container, and the stirrer (Mazela 1000, manufactured by Tokyo Rika Co., Ltd.) is heated while heating the container with hot water of about 60 ° C. ) Was completely dissolved in MEK to obtain a polyester resin solution having a solid content concentration of 40% by mass.
[Phase inversion emulsification step] Next, 500 g of the above polyester resin solution was charged into a jacketed glass container (internal volume 2 L), and cold water was passed through the jacket to maintain the system temperature at 13 ° C, with a stirrer (manufactured by Tokyo Rika Co., Ltd., MAZELA1000). Stirring was performed (rotation speed: 600 rpm). Next, 8.5 g of triethylamine was added as a basic compound while stirring, and then 491.5 g of distilled water at 13 ° C. was added at a rate of 100 g / min. During addition of the whole amount of distilled water, the system temperature was always 15 ° C. or lower. After completion of the addition of distilled water, the mixture was stirred for 30 minutes to obtain a polyester resin aqueous dispersion having a solid content concentration of 20% by mass and an organic solvent content of 3% by mass or more.

(2) Step 800 g of the polyester resin aqueous dispersion obtained in the step (1) and 52.3 g of distilled water were placed in a 2 L flask, and the organic solvent was removed by distillation at normal pressure. Distillation was terminated when the amount of distillation reached about 360 g, and after cooling to room temperature, it was filtered through a 250 mesh (opening 0.071 mm) stainless steel filter. Subsequently, after measuring the solid content concentration of this aqueous dispersion, distilled water was added so that the solid content concentration was 30% by mass. The aqueous polyester resin dispersion thus obtained had a solid content concentration of 30.2% by mass and a pH of 6.5. The content of the organic solvent was 0.01% by mass or less.

(3) Step While stirring 500 g of the polyester resin aqueous dispersion obtained in the step (2), 0.7 g of 28% by mass of ammonia water was added to obtain an aqueous dispersion of the present invention.
The solid content concentration of this aqueous dispersion was 30.2% by mass, and the pH was 9.3.

<Comparative Example 1>
Various performance evaluation was performed about the polyester resin aqueous dispersion obtained at the process of (2) of Example 1. FIG.
<Comparative example 2>
Various performance evaluation was performed about the polyester resin aqueous dispersion obtained at the process of (2) of the reference example 1. FIG.
<Comparative Example 3>
Various performance evaluation was performed about the polyester resin aqueous dispersion obtained at the process of the reference example 2 (2).
<Comparative example 4>
Various performance evaluation was performed about the polyester resin aqueous dispersion obtained at the process of ( 3 ) of Example 3. FIG.

<Comparative Example 5>
According to the same method as in Example 1, except that the amount of triethylamine added in the step (1) was 46.6 g, the amount of distilled water added was 453.4 g, and the step (3) was omitted. An aqueous resin dispersion was obtained. The content of the organic solvent in the aqueous dispersion obtained in the step (2) of this comparative example was 0.01% by mass or less.
<Comparative Example 6>
A polyester resin was prepared in the same manner as in Reference Example 2 except that the amount of ammonia water added in the step (1) was 5.0 g, the amount of distilled water added was 495 g, and the step (3) was omitted. An aqueous dispersion was obtained. The content of the organic solvent in the aqueous dispersion obtained in the step (2) of this comparative example was 0.01% by mass or less.
<Comparative Example 7>
Except that 2.5 g of N, N-dimethylethanolamine was added instead of triethylamine in the step (1), the amount of distilled water added was 497.5 g, and the step (3) was omitted, A polyester resin aqueous dispersion was obtained in the same manner as in Example 3 . The content of the organic solvent in the aqueous dispersion obtained in the step (2) of this comparative example was 0.01% by mass or less.

In Table 2, the characteristic value and performance of the polyester resin aqueous dispersion obtained in Examples 1 to 3 , Reference Examples 1 to 3 and Comparative Examples 1 to 7 are shown.

  From the above Examples and Comparative Examples, the aqueous polyester resin dispersion of the present invention has a very high impact stability because the pH can be controlled within a predetermined range, and further has excellent storage stability. It turns out that the resin film formed is excellent in the adhesiveness to a base material.

Claims (4)

A polyester resin aqueous dispersion comprising a polyester resin having an acid value of 4.3 to 7.9 mg KOH / g and a basic compound and an organic solvent content of less than 0.5% by mass, wherein the aqueous dispersion The polyester resin aqueous dispersion is characterized by having a pH of 8-14.   The aqueous polyester resin dispersion according to claim 1, wherein the basic compound is an organic amine and / or ammonia.   The polyester resin aqueous solution according to claim 1 or 2, wherein the polyester resin is a polyester resin containing an aromatic polybasic acid as a constituent polybasic acid component in an amount of 50 mol% or more based on the total amount of the polybasic acid component. Dispersion. The manufacturing method of the polyester resin aqueous dispersion in any one of Claims 1-3 including the process of following (1)-(3);
(1) A step of obtaining an aqueous polyester resin dispersion containing a polyester resin having an acid value of 4.3 to 7.9 mg KOH / g and a basic compound and having an organic solvent content of 3% by mass or more. A step of dissolving the polyester resin in an organic solvent and adding water and a basic compound to the polyester resin solution for phase inversion emulsification ,
(2) A step of removing the organic solvent from the aqueous polyester resin dispersion obtained in step (1) to obtain an aqueous polyester resin dispersion having an organic solvent content of less than 0.5% by mass, and (3) step A step of adding a basic compound to the aqueous polyester resin dispersion obtained in (2).