JPH09296100A - Aqueous polyester resin dispersion and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous polyester resin dispersion which comprises a polyester resin (A), a basic compound (B), an amphiphilic organic solvent (C) and a compound (D) having a protective colloidal effect, and which has excellent film processability, water resistance, corrosion resistance, chemical resistance, weatherability and adhesive properties and also excellent storability even at a high solid concentration realized by homogeneously dispersing fine particles of the component (A) in an aqueous medium. SOLUTION: The component A substantially comprises a polybasic acid (such as terephthalic acid) and a polyhydric alcohol (such as ethylene glycol) and has an acid value of 10 to 40mgKOH/g and a weight-average molecular weight of at least 9,000 or a relative viscosity of at least 1.20. In the particle size distribution of the component A after the dispersion, the median diameter based on the volume is 2μm or smaller and the maximum particle size is not larger then 10μm. The component B is, for example, N,N-dimethylethanolamine. The component C effective in plasticizing the component A is, for example, ethylene glycol n-butyl ether. The component D is, for example, a polyvinyl alcohol.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester resin aqueous dispersion and a method for producing the same.

[0002]

2. Description of the Related Art A high molecular weight polyester resin (so-called oil-free alkyd resin) consisting essentially of polybasic acids and polyhydric alcohols is not only used as fibers, films and various molding materials, but also as paints and inks. Also in the field of adhesives, coating agents, etc., as a binder component of various types due to good pigment dispersibility, excellent processability of the formed film, chemical resistance, weather resistance, adhesion to various substrates, etc. Used in large quantities. When such a high molecular weight polyester resin contains an aromatic polybasic acid, particularly terephthalic acid, as its acid component, the processability and water resistance of the coating film are not sacrificed without sacrificing other physical properties of the coating film formed therefrom. It is well known that the resistance, chemical resistance and weather resistance can be improved. However, as the proportion of aromatic polybasic acid, especially terephthalic acid, in the total acid component increases, the polyester resin cannot be stably dissolved in a general-purpose organic solvent at a high concentration, and thus cannot be shaped in a liquid state. However, this has caused a significant limitation on the use of such resins. Therefore, it has been desired for many years to develop a "liquefaction" technique of such a resin at a high concentration.

On the other hand, from the standpoints of recent environmental protection, resource conservation, regulation of dangerous substances by the Fire Service Act, etc., and improvement of the working environment, "liquefaction" of a resin by an organic solvent is called "liquefaction" by an aqueous medium,
In other words, there are active movements to substitute water. The same applies to polyester resins.For high-molecular-weight polyester resins containing a large amount of aromatic polybasic acid, especially terephthalic acid as an acid component, not only a film having excellent performance is formed, but also such a resin skeleton is resistant. Due to its excellent hydrolyzability, the aqueous dispersion obtained from this resin is expected to have excellent storage stability.

As a method for making a high molecular weight polyester resin water-soluble, (a) a resin is dissolved in an organic solvent or melted to be liquefied, and this is added to an aqueous medium while applying high-speed shearing to obtain fine particles. Then, there is a method of stabilizing the dispersion with the aid of a dispersion stabilizer such as a surfactant (forced emulsification method). However, in this method, since the resin itself is hydrophobic, a large amount of a low molecular weight hydrophilic compound (surfactant) must be used in order to stabilize the dispersion of the generated fine particles, and the film formed However, there is a problem that the water resistance is extremely poor. Further, (b) Japanese Patent Publication No. 59-30186, Japanese Patent Publication No. 60-1334, and Japanese Patent Publication No. 61-58.
In Japanese Patent Publication No. 092, Japanese Patent Publication No. 62-19789, Japanese Patent Publication No. 62-21380, Japanese Patent Publication No. 62-21381, etc., a monomer component having a sulfonate metal base such as 5-sodium sulfoisophthalic acid is used. There is disclosed a method of synthesizing a polyester resin by introducing a metal sulfonate metal base, which is a strong hydrophilic group, into the resin to achieve water solubilization. According to this method, since the hydrophilic group is incorporated into the resin, even if a small amount of the hydrophilic group is made water-soluble, the ionic group remains as it is in the film after drying, so that the water resistance of the film is increased. Resistance, corrosion resistance,
There is a problem that chemical resistance is not sufficient.

On the other hand, (c) a polyester resin having a high acid value is synthesized, and a carboxyl group in the resin is neutralized with a volatile basic compound such as an organic amine compound to give an ionic hydrophilic group. The method of generating water in the resin to achieve water solubilization has the advantage that the basic compound is volatilized in the step of drying the film, so that the film is excellent in water resistance, corrosion resistance, chemical resistance, and the like. As a specific method for achieving water-solubilization by the method (c), (1) a resin is dissolved in an organic solvent or is melted and liquefied, and a shearing force is applied to an aqueous medium. A method of making the particles fine by adding them, and stabilizing the dispersion by self-emulsification without agglomeration of the generated fine particles by the electric repulsive force of the neutralizing salt, (2) dissolving the resin in an organic solvent, and adding water to this. A method of obtaining a stable aqueous dispersion by introducing a medium with stirring and inversion of the W / O emulsion into an O / W emulsion (phase inversion emulsification method), and further (3) JP-B-54-23694. Japanese Patent Publication No. 54-23695, Japanese Patent Publication No. 54-23
As disclosed in Japanese Patent Publication No. 696, Japanese Patent Publication No. 58-25350, Japanese Patent Publication No. 58-33900, etc., a polyester resin is mechanically pulverized in advance into fine particles,
A method of uniformly dispersing this in an aqueous medium (slurry paint), and (4) as a modified method of (1), a method of ejecting the liquefied material into an aqueous medium at high pressure to form fine particles, and the like. Are known.

However, any of the above-mentioned methods has a problem in making a high-molecular-weight polyester resin containing a large amount of an aromatic polybasic acid, particularly terephthalic acid, as an acid component, and the fine particles of the polyester resin are high. It has hitherto been impossible to obtain an aqueous dispersion stably dispersed in an aqueous medium at a concentration. That is, the polyester resin does not dissolve in a general-purpose organic solvent at a high concentration, and therefore, even if the aqueous solution is achieved by any of the methods (1), (2), and (4), the polyester resin is not dissolved in the aqueous dispersion. A large amount of organic solvent remains in the water, and the original meaning of making the water-based solution is diminished. On the contrary,
For example, JP-A-60-248734 and JP-A-60-
Japanese Patent No. 248735 discloses a method in which a specific organic solvent having a boiling point of 100 ° C. or lower is used to make it aqueous, and then a part or all of the organic solvent is removed to the outside of the system. However, in the experiments conducted by the present inventors, it was impossible to stably dissolve the polyester resin at a concentration of 50% by weight or more even when refluxing in these organic solvents, and it was found that the solvent removal step It has been found that not only a significant amount of time and energy is required, but also a large amount of a hydrophilic compound such as a surfactant or a compound having a protective colloid action is required to prevent aggregation of resin fine particles during the solvent removal process. .

On the other hand, in the method in which the polyester resin melt is brought into direct contact with the aqueous medium, the polyester resin melt usually cannot secure sufficient fluidity unless it is heated to 200 ° C. or higher, so that the work of hydration is accompanied by danger. Moreover, there is a problem that the polyester resin is hydrolyzed by contact with an aqueous medium at a high temperature. Further, in the above method (3), various improvements have been attempted in order to stabilize the dispersion of resin particles, but it is difficult to obtain fine particles having an average particle diameter of 1 μm or less by mechanical pulverization. Moreover, since only resin particles having a wide particle size distribution can be obtained, the storage stability of the obtained aqueous dispersion cannot be said to be sufficient, and the film formed from this has poor gloss and should be formed into a thin film. There was a problem that I could not do it.

[0008]

In view of the above situation, the first object of the present invention is, firstly, to contain a large amount of an aromatic polybasic acid, particularly terephthalic acid, as an acid component constituting a polyester resin, (1) The polyester resin does not contain any special monomer component, a structure in which an ionic group remains even after the coating is dried, or a structure that is easily hydrolyzed, (2)
Externally added, low molecular weight hydrophilic compounds such as surfactants are not included, and the content of organic solvent is sufficiently reduced. (3) Extremely excellent storage stability even at high solid content In addition, (4) excellent film formability, (5) excellent film formability, water resistance, corrosion resistance, chemical resistance,
To provide a polyester resin aqueous dispersion that exhibits weather resistance and adhesion to various substrates, and secondly, to provide such a polyester resin aqueous dispersion with stable quality without using special equipment. To provide a manufacturing method capable of producing, thirdly, in addition to having the advantages of (1) to (5) above,
Further, to provide a polyester resin water dispersion in which the water resistance of the formed coating is further improved. Fourth, to produce such a polyester resin water dispersion with stable quality without using special equipment. It is to provide a manufacturing method capable of

[0009]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found the following facts and arrived at the present invention. That is, in the self-emulsification method, the carboxyl group in the hydrophobic polyester resin and the hydrophilic basic compound come into contact with each other to generate an ionic group (neutralizing salt), thereby stabilizing the dispersion of the polyester resin fine particles. However, the polyester resin is made into fine particles, and
In order to increase the frequency of contact between the carboxyl group in the resin and the basic compound and to promote the hydration smoothly, the polyester resin is liquefied, and the system is stirred at high speed after the liquefied material comes into contact with the aqueous medium. That was previously considered an essential condition.

On the other hand, the first of the facts found by the present inventors is that if the polyester resin has a specific amount of acid value, the polyester resin is liquefied into pellets or granules for water treatment. Even if it is used for the polyester resin, a specific organic compound (organic solvent) having a plasticizing ability with respect to the polyester resin is used, and the glass transition temperature of the resin or 60 ° C., whichever is higher, is used for a predetermined condition. It means that the water-making (resin microparticulation) proceeds at an astonishing speed by stirring with. The second fact is that in an aqueous dispersion of a polyester resin produced by an aqueous treatment, the acid value of the polyester resin, the type and amount of the organic solvent used, the type and amount of the basic compound, and the aqueous treatment conditions are used. That is, the particle size distribution of the resin fine particles can be highly controlled. And the third fact is that by optimizing the particle size distribution of the resin fine particles in the polyester resin aqueous dispersion, and further using a very small amount of a compound having a specific protective colloid action in the aqueous dispersion, the aqueous dispersion of the polyester resin can be obtained. The storage stability is remarkably improved, and the film formed is to exhibit the excellent performance inherent in the polyester resin.

Furthermore, when the polydispersity of the molecular weight distribution of the polyester resin in the polyester resin aqueous dispersion is increased to limit the acid value of the polyester resin and the content of the compound having a protective colloid action, ~ It is the fact that a polyester resin aqueous dispersion which exhibits the third fact and in which the water resistance of the obtained coating film is further improved can be obtained. The present inventors have examined the water-based conversion of a high molecular weight polyester resin containing a large amount of an aromatic polybasic acid, especially terephthalic acid, as an acid component. It was found to be expressed.

That is, the gist of the present invention is, firstly, a polyester resin water dispersion containing the following components (A), (B), (C) and (D), in which the polyester resin fine particles are It is a polyester resin water dispersion characterized by being uniformly dispersed in an aqueous medium. (A) Polyester resin substantially composed of polybasic acid and polyhydric alcohol, having an acid value of 10 to 40 mgKOH / g and a weight average molecular weight of 9,000 or more or a relative viscosity of 1.20 or more (B) ) Basic compound (C) 0.5 to 10% by weight of an amphipathic organic solvent having a plasticizing ability for a polyester resin with respect to a polyester resin aqueous dispersion (D) A compound having a protective colloid action is a polyester 0.01 to 3% by weight of resin

Secondly, it comprises a dispersion step, a heating step, an aqueous step and a cooling step. In the dispersion step, all of the polyester resin shown in (A) below and (B) under agitation,
All or part of the components shown in (C) and (D) are roughly dispersed in an aqueous medium, and in the heating step and the hydration step, the remaining components are added with stirring, or while being added, at 60 ° C. and polyester. A method for producing a polyester resin aqueous dispersion, which comprises heating to a higher temperature of the glass transition temperatures of the resin to 90 ° C. and continuously stirring at this temperature for 15 to 120 minutes. (A) Polyester resin substantially composed of polybasic acid and polyhydric alcohol, having an acid value of 10 to 40 mgKOH / g and a weight average molecular weight of 9,000 or more or a relative viscosity of 1.20 or more (B) ) Basic compound (C) 0.5 to 10% by weight of an amphipathic organic solvent having a plasticizing ability for a polyester resin with respect to a polyester resin aqueous dispersion (D) A compound having a protective colloid action is a polyester 0.01 to 3% by weight of resin

Thirdly, a polyester resin water dispersion containing the following components (A '), (B), (C) and (D'), wherein the polyester resin fine particles are uniformly dispersed in an aqueous medium. It is a polyester resin aqueous dispersion characterized by being dispersed. (A ') is substantially composed of a polybasic acid and a polyhydric alcohol, has an acid value of 8 to 36 mgKOH / g, a number average molecular weight of 4,000 or more, and a dispersity of the molecular weight distribution of 4.
0 or more polyester resin (B) basic compound (C) 0.5 to 10 wt% of an amphipathic organic solvent having a plasticizing ability to the polyester resin with respect to the polyester resin aqueous dispersion (D ' ) 0.05% by weight or less of a compound having a protective colloid action with respect to the polyester resin

Fourthly, it comprises a dispersing step, a heating step, an hydration step and a cooling step. In the dispersing step, all the polyester resins shown in (A ') below and (B), (C) and All or part of the components shown in (D ') are roughly dispersed in an aqueous medium, and in the heating step and the hydration step, the remaining components are added with stirring, or at 60 ° C. and the glass transition of the polyester resin while being added. The higher of the temperatures is heated to 90 ° C, and at this temperature 15 to 120
A method for producing a polyester resin aqueous dispersion, which comprises continuously stirring for a minute. (A ') is substantially composed of a polybasic acid and a polyhydric alcohol, has an acid value of 8 to 36 mgKOH / g, a number average molecular weight of 4,000 or more, and a dispersity of the molecular weight distribution of 4.
0 or more polyester resin (B) basic compound (C) 0.5 to 10 wt% of an amphipathic organic solvent having a plasticizing ability to the polyester resin with respect to the polyester resin aqueous dispersion (D ' ) 0.05% by weight or less of a compound having a protective colloid action with respect to the polyester resin

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. Polyester Resin In the present invention, the polyester resin (A) or polyester resin (A ′) described below is used. In the polyester resin (A), the acid value is 10 to 40 mgKOH / g,
It is preferably 10 to 35 mg KOH / g. If this acid value exceeds 40 mgKOH / g, the water resistance of the coating film formed may be poor. On the other hand, the acid value is 10 mgKOH /
If it is less than g, the amount of carboxyl groups that contribute to water solubilization is insufficient and a good aqueous dispersion cannot be obtained. The weight average molecular weight measured by GPC (gel permeation chromatography, converted to polystyrene) is 9,000 or more, or 1% by weight in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane in an equal weight ratio. The relative viscosity when dissolved at a concentration of 1. and measured at 20 ° C. is 1.
Must be 20 or more. Weight average molecular weight is 9.0
When it is less than 00 or the relative viscosity is less than 1.20, sufficient processability is not imparted to the coating film formed from the aqueous dispersion of the polyester resin. Furthermore, the weight average molecular weight of the polyester resin is preferably 12,000 or more, and more preferably 15,000 or more. The upper limit is preferably 45,000 or less. When it exceeds 45,000, not only the operability during the production of the polyester resin is deteriorated, but also the viscosity of an aqueous dispersion using such a polyester resin may become abnormally high. The relative viscosity is preferably 1.22 or more, more preferably 1.24 or more. The upper limit is preferably 1.95 or less, and when it exceeds this value, not only the operability during the production of the polyester resin is deteriorated, but also the viscosity of the water dispersion using such a polyester resin becomes extremely high. There is.

In the polyester resin (A '), the acid value is 8-36 mgKOH / g, preferably 8-33 mgK.
OH / g, more preferably 10-28 mg KOH / g
It is. If the acid value exceeds 36 mgKOH / g, the water resistance of the formed coating may be poor. On the other hand, when the acid value is less than 8 mgKOH / g, the amount of the carboxyl groups that contribute to water-solubilization is insufficient and a good water dispersion cannot be obtained. Further, in the polyester resin (A '), the number average molecular weight measured by GPC is 4,000.
Must be 0 or greater. Number average molecular weight is 4,000
When the amount is less than the above, not only sufficient workability and chemical resistance but also water resistance are not imparted to the coating film formed from the aqueous dispersion of the polyester resin. Furthermore, the number average molecular weight of the polyester resin is preferably 4,500 or more, more preferably 5,000 or more. The upper limit is preferably 15,000 or less.
When it exceeds 15,000, it becomes difficult not only to impart a sufficient acid value to the polyester resin, but even if the acid value is sufficient, an aqueous dispersion using such a polyester resin has an abnormal viscosity. It can be high.

In the polyester resin (A '), the polydispersity of the molecular weight distribution, which is defined as a value obtained by dividing the weight average molecular weight of the polyester resin measured by GPC by the number average molecular weight, is 4.0 or more. Is particularly important for developing excellent water resistance. That is, when the polydispersity of the molecular weight distribution is less than 4.0, the hydration of the polyester resin having a low acid value does not smoothly proceed, and the storage stability is satisfied even if an aqueous dispersion is obtained. Therefore, the amount of the compound having a protective colloidal action necessary for the purpose to be increased becomes large. The degree of dispersion of the polyester resin is preferably 4.3 or more, more preferably 4.5 or more. The upper limit is preferably 15 or less. The production of a polyester resin having a molecular weight of more than 15 is extremely difficult because the conditions must be controlled excessively, and it is difficult to satisfy the above-mentioned conditions concerning the number average molecular weight.

The polyester resins (A) and (A ')
Is essentially water-insoluble which does not disperse or dissolve in water by itself, and is substantially synthesized from polybasic acids and polyhydric alcohols. The constituent components of these polyester resins will be described below.

Among the polybasic acids, examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and the like. 5-sodium sulfoisophthalic acid or 5-hydroxyisophthalic acid can be used. As the aliphatic dicarboxylic acid, oxalic acid, (anhydrous) succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, saturated dicarboxylic acid such as hydrogenated dimer acid, fumaric acid, (anhydrous) maleic acid, (anhydrous) ) Itaconic acid, (anhydrous) citraconic acid, unsaturated dicarboxylic acids such as dimer acid and the like can be mentioned, and as the alicyclic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1 , 2-cyclohexanedicarboxylic acid,
2,5-norbornene dicarboxylic acid (anhydride), tetrahydrophthalic acid (anhydride), etc. can be mentioned.

The total content of aromatic polybasic acids in all acid components is preferably 50 mol% or more. If this value is less than 50 mol%, the structure derived from the aliphatic polybasic acid and the alicyclic polybasic acid occupies the majority of the resin skeleton, so that the hardness, stain resistance, and water resistance of the formed coating film. And the aliphatic and / or alicyclic ester bond has a lower hydrolysis resistance than the aromatic ester bond, so that the storage stability of the aqueous dispersion may decrease. In order to ensure the storage stability of the aqueous dispersion, the content of aromatic polybasic acid in all the acid components is preferably 70 mol% or more, and the processing is performed while balancing the other properties of the formed film. In order to improve the properties, water resistance, chemical resistance, and weather resistance, it is preferable that 65 mol% or more of all acid components constituting the polyester resin is terephthalic acid in order to achieve the object of the present invention. Particularly preferred.

On the other hand, with respect to the polyhydric alcohol component, examples of glycols include aliphatic glycols having 2 to 10 carbon atoms, alicyclic glycols having 6 to 12 carbon atoms, and ether bond-containing glycols. As the aliphatic glycol having 2 to 10 carbon atoms, ethylene glycol, 1,2-
Propylene glycol, 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, etc., with 6 carbon atoms
Examples of the alicyclic glycols of to 12 include 1,4-cyclohexanedimethanol and the like. As the ether bond-containing glycol, diethylene glycol,
Glycols obtained by adding 1 to several moles of ethylene oxide or propylene oxide to two phenolic hydroxyl groups of triethylene glycol, dipropylene glycol, and bisphenols, for example, 2,
2-bis (4-hydroxyethoxyphenyl) propane etc. can be mentioned. Polyethylene glycol, polypropylene glycol and polytetramethylene glycol can also be used if necessary. However, since the ether structure reduces the water resistance and weather resistance of the polyester resin coating, the amount used is 10% by weight of the total polyhydric alcohol component.
Hereafter, it is preferable to further limit the content to 5% by weight or less.

In the present invention, 50 mol% or more, especially 65 mol% of the total polyhydric alcohol component of the polyester resin is used.
The above is preferably composed of ethylene glycol and / or neopentyl glycol. Since ethylene glycol and neopentyl glycol are industrially produced in large quantities, they are inexpensive, and the properties of the formed film are well balanced. The ethylene glycol component is particularly chemical resistant, and the neopentyl glycol component is particularly It has the advantage of improving weather resistance.

The polyester resin used in the present invention is
If necessary, a trifunctional or higher functional polybasic acid and / or a polyhydric alcohol can be copolymerized. As the trifunctional or higher functional polybasic acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, ( Anhydrous) benzophenone tetracarboxylic acid,
Trimesic acid, ethylene glycol bis (anhydrotrimellitate), glycerol tris (anhydrotrimellitate), 1,2,3,4-butanetetracarboxylic acid and the like are used. On the other hand, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like are used as the trifunctional or higher polyhydric alcohol. The trifunctional or higher polybasic acid and / or polyhydric alcohol is copolymerized in the range of 10 mol% or less, preferably 5 mol% or less, based on the total acid component or the total alcohol component. The high processability of the coating film, which is an advantage of the polyester resin, is not exhibited.

If necessary, fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid, and ester-forming derivatives thereof, benzoic acid, p-tert-butylbenzoic acid are used. , High-boiling monocarboxylic acids such as cyclohexanoic acid and 4-hydroxyphenylstearic acid, stearyl alcohol,
High-boiling monoalcohol such as 2-phenoxyethanol, ε-caprolactone, lactic acid, β-hydroxybutyric acid,
A hydroxycarboxylic acid such as p-hydroxybenzoic acid or an ester-forming derivative thereof may be used.

The polyester resin is synthesized from the above-mentioned monomers by a known method. For example,
(A) All monomer components and / or low polymers thereof are reacted in an inert atmosphere at 180 to 250 ° C. for about 2.5 to 10 hours to carry out an esterification reaction, and subsequently in the presence of a catalyst, at 1 Torr or less. A method of obtaining a polyester resin by advancing a polycondensation reaction under a reduced pressure at a temperature of 220 to 280 ° C. until a desired melt viscosity is reached, and (b) ending the polycondensation reaction at a stage before reaching a target melt viscosity. Then, in the next step, the reaction product is mixed with a chain extender selected from polyfunctional epoxy compounds, isocyanate compounds, oxazoline compounds, etc., and reacted for a short time to increase the molecular weight, (c ) The polycondensation reaction is advanced to a stage above the target melt viscosity, the monomer component is further added, and depolymerization is carried out in an inert atmosphere at atmospheric pressure to pressurized system to achieve the target melt viscosity. And a method such as to obtain a polyester resin viscosity.

From the viewpoint of water resistance of the coating film formed, it is preferable that the carboxyl group necessary for water solubilization is unevenly distributed at the terminal of the resin molecular chain rather than in the resin skeleton. When a polyester resin (A) is produced, a method for introducing a specific amount of a carboxyl group to the molecular chain end of a high molecular weight polyester resin without causing side reaction or gelation is
In the above method (a), 3 after the start of the polycondensation reaction.
A method of adding a polybasic acid component having a functionality or higher, or a method of adding an acid anhydride of a polybasic acid immediately before the end of the polycondensation reaction,
In the method (b), a method of increasing the molecular weight of a low-molecular-weight polyester resin in which most of the molecular chain ends are carboxyl groups by a chain extender, and in the method (c), a polybasic acid component is used as a depolymerizing agent. The method used is the preferred embodiment.

In particular, in the case of producing the polyester resin (A '), a method of increasing the molecular weight of the low molecular weight polyester resin in which most of the molecular chain terminals are carboxyl groups in the above method (b) by a chain extender, Method (c)
In the above, a method using a polybasic acid component as a depolymerizing agent is a preferred embodiment. However, in the case of the polyester resin (A ′), the transesterification reaction always occurs as a competitive reaction at a high temperature of 200 ° C. or higher, and as a result, the dispersity of the molecular weight distribution of the resin decreases with time. Therefore, in any of the above methods, for the final step, the reaction should be terminated at a stage before the system reaches equilibrium.

The content of the polyester resin in the polyester resin aqueous dispersion of the present invention is determined by its intended use,
It should be appropriately selected depending on the dry film thickness and the molding method, but it is generally preferable to use it in the range of 0.5 to 50% by weight, and particularly 1 to 40% by weight. As described below,
The polyester resin aqueous dispersion of the present invention has an advantage that it is excellent in storage stability even when the polyester resin content is as high as 20% by weight or more in solid concentration. But,
When the content of the polyester resin exceeds 50% by weight, the viscosity of the polyester resin aqueous dispersion becomes extremely high, which may make the molding substantially difficult.

Basic Compound When the polyester resin according to the present invention is dispersed in an aqueous medium, it is neutralized with a basic compound. In the present invention, the neutralization reaction with the carboxyl group in the polyester resin is the driving force for hydration (formation of resin fine particles), and due to the electric repulsive force between the generated carboxy anions, a very small amount of protective colloid action described below. When used in combination with a compound having, it is possible to prevent aggregation between fine particles. The basic compound is preferably a compound that volatilizes during film formation or bake-curing with a curing agent. Examples of such compounds include ammonia and organic amine compounds having a boiling point of 250 ° C. or lower. Examples of desirable organic amine compounds include 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-
Examples thereof include ethylmorpholine. The basic compound is preferably added in an amount such that it can be at least partially neutralized, that is, 0.2 to 1.5 times equivalent to the carboxyl group, depending on the carboxyl group contained in the polyester resin. It is more preferable to add 4 to 1.3 times equivalent amount. If the amount is less than 0.2 times the equivalent amount, the effect of addition of the basic compound is not recognized, and if the amount exceeds 1.5 times the equivalent amount, the aqueous polyester resin dispersion may remarkably thicken.

Amphipathic Organic Solvent In the present invention, an amphipathic organic compound having a plasticizing ability for the polyester resin is required in the hydration step for the purpose of accelerating the hydration treatment rate. However, if the boiling point exceeds 250 ° C, the evaporation rate is too slow to remove it sufficiently even when the coating is dried. So-called general-purpose compounds called organic solvents are targeted.

The characteristics required for the organic solvent in the present invention are that it is amphipathic and that it has a plasticizing ability for the polyester resin. Here, the amphipathic organic solvent has a solubility in water at 20 ° C. of at least 5 g / L or more, and preferably 10 g / L or more. When the solubility is less than 5 g / L, the effect of accelerating the aqueous treatment speed is poor. The plasticizing ability of the organic solvent can be judged by the following simple test. That is, a 3 cm × 3 cm × 0.5 cm (thickness) square plate was prototyped from the target polyester resin,
This is immersed in 50 ml of an organic solvent and left to stand in an atmosphere of 25 to 30 ° C. The shape of the square plate is obviously deformed after 3 hours, or when a 0.2 cm diameter stainless steel rod is contacted while statically applying a force of 1 kg / cm ^{2 in} the thickness direction. In addition, when 0.3 cm or more of the round bar penetrates the square plate, it is judged that the organic solvent has a plasticizing ability. The organic solvent judged not to have the plasticizing ability is poor in the effect of accelerating the aqueous treatment speed.

As the organic solvent, ethanol, n
-Propanol, isopropanol, n-butanol,
Isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-
Alcohols such as 1-propanol, n-hexanol, and cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, and isophorone, ethers such as tetrahydrofuran and dioxane, ethyl acetate, n-propyl acetate, Esters such as isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate and dimethyl carbonate, ethylene glycol, ethylene glycol monomethyl ether. , Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol monomethy Ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, glycol derivatives such as propylene glycol methyl ether acetate, and further, 3-methoxy-3-
Examples thereof include methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like. These solvents may be used alone or in combination of two or more.

Of these exemplified organic solvents, a single compound satisfying the following two conditions may be used alone, or
It is preferable to use a mixture of two or more species because not only the effect of accelerating the aqueous treatment speed is particularly excellent, but also the storage stability of the resulting polyester resin aqueous dispersion is excellent. (Condition 1) The molecule has a hydrophobic structure in which four or more carbon atoms are directly bonded. (Condition 2) Pauling at the end of the molecule.
Has a substituent containing at least one atom having an electronegativity of 3.0 or more, and is ¹³ C- of a carbon atom directly bonded to an atom having an electronegativity of 3.0 or more in the substituent. Chemical shift of NMR (nuclear magnetic resonance) spectrum at room temperature, CDCl
Have polar substituents such that the measured value in ₃ is 50 ppm or more

Examples of the substituent defined by the condition 2 include an alcoholic hydroxyl group, a methyl ether group, a ketone group, an acetyl group, a methyl ester group and the like, and among the compounds satisfying the above two conditions, particularly preferable. As the organic solvent, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, n-hexanol,
Alcohols such as cyclohexanol, methyl isobutyl ketone, ketones such as cyclohexanone, acetic acid-n-
Butyl, isobutyl acetate, esters such as sec-butyl acetate and 3-methoxybutyl acetate, glycol derivatives such as ethylene glycol monobutyl ether, diethylene glycol monobutyl ether and propylene glycol monobutyl ether, and further 3-methoxy-3.
-Methylbutanol and 3-methoxybutanol can be exemplified.

If the boiling point of such an organic solvent is 100 ° C. or lower, or if it can be azeotropically distilled with water, a part or all of the organic solvent is removed to the outside of the system during the aqueous step or the subsequent step (stripping). However, the final amount is 0.5 to 10% by weight, preferably 0.5 to 8.0% by weight, more preferably 1.0 to 5.0% by weight, based on the polyester resin aqueous dispersion. Should be included. 0.5
The polyester resin aqueous dispersion containing 10 to 10% by weight is excellent in storage stability and film forming property. 0.5
If it is less than 10% by weight, there are problems that it may take a long time to become aqueous and that polyester resin fine particles having a desired particle size distribution may not be produced. On the other hand, if the amount exceeds 10% by weight, not only the original purpose of making the aqueous solution is impaired but also the abundance of secondary particles in the aqueous dispersion described later becomes high, so that the viscosity of the aqueous dispersion becomes abnormally high. In some cases, the storage stability may be poor, or the film-forming property may be poor.

Compound Having Protective Colloid Action In the present invention, if necessary, the step of removing (stripping) the above-mentioned organic solvent from the outside of the system or the purpose of ensuring the stability of the aqueous dispersion during storage may be carried out. A compound having a protective colloid action is used. The protective colloid in the present invention is adsorbed on the surface of resin fine particles in an aqueous medium, so-called,
The effect of preventing adsorption between resin fine particles by showing a stabilizing effect called "mixing effect", "osmotic pressure effect" or "volume limiting effect". As a compound having a protective colloid action, polymerization of a vinyl monomer containing polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, polyvinylpyrrolidone, polyacrylic acid, acrylic acid and / or methacrylic acid as one component. Examples thereof include polyitaconic acid, gelatin, gum arabic, casein, and swelling mica. Such a compound is water-soluble or is made water-soluble by partially neutralizing it with a basic compound, but in order not to impair the water resistance of the formed film, the basic compound is ammonia and / or the above-mentioned compound. Must be an organic amine compound. Further, in order to exhibit the action as a protective colloid even if added in a small amount and not impair the water resistance, chemical resistance, etc. of the formed film, the compound having a protective colloid action has a number average molecular weight of 1,500 or more. Are preferred, and those of 2,000 or more are more preferred, and those of 2,500 or more are more preferred.

The amount of the compound having the protective colloid action used is 0.
It is from 0.01 to 3% by weight, preferably from 0.03 to 2% by weight. Within this range, the stability of the polyester resin water dispersion during the hydration step and storage can be significantly improved without deteriorating the various properties of the formed coating film. Further, by using such a compound having a protective colloid action, the acid value of the polyester resin and the content of the organic solvent can be reduced. Further, the amount used with respect to the polyester resin (A ′) is 0.05% by weight or less,
Preferably 0.03% by weight or less, 0.05% by weight
If it is below, the stability of the polyester resin water dispersion during the hydration step and storage can be significantly improved without deteriorating the various properties of the formed film.

(Production of Polyester Resin Aqueous Dispersion) The polyester resin aqueous dispersion of the present invention is produced by substantially four steps including a dispersing step, a heating step, an aqueous step and a cooling step. In the dispersing step, all or part of the polyester resin (A) component and other components (B), (C) and (D) or all (A ′) component and other (B) are stirred under stirring. ), (C) and (D ') are wholly or partly dispersed in an aqueous medium, and in the heating step and the hydration step, 60 ° C. and polyester are added while adding or adding the remaining ingredients with stirring. The glass transition temperature of the resin, whichever is higher, is heated to 90 ° C, and at this temperature, 15 to 1
By continuously stirring for 20 minutes, the polyester resin is made into fine particles, and in the cooling step, the obtained polyester resin aqueous dispersion is cooled to room temperature. All of these steps are indispensable steps, and it is preferable to carry out them continuously. However, one feature of the present invention is that no special equipment is required to carry out these steps.

As the treatment device, it is sufficient that the aqueous medium, the polyester resin powder or granules, and the other components charged in the tank can be appropriately stirred, and the inside of the tank can be heated to 60 to 90 ° C., and the solid / liquid stirring is performed. As a device or an emulsifier, a device widely known to those skilled in the art can be used. As such an apparatus, a uniaxial stirrer such as a propeller mixer and a turbine mixer, a turbine-stator type high speed rotary stirrer (manufactured by Tokushu Kika Kogyo Co., Ltd .: “TK Homo-Mixe”)
r "," TK Homo-Jettor ", IKA-
Manufactured by MASCHINENBAU: "Ultra-Tur
"rax"), combined stirrer (manufactured by Tokushu Kika Kogyo Co., Ltd.):
"TK Agi-Homo-Mixer", "T.
K. A high-speed shearing type mixer such as "Combimix" and a low-speed sliding type kneading paddle with a scraper for scraping the tank wall surface and an anchor mixer are used together).
The processing apparatus may be a batch type, or may be a continuous production type in which the raw material is charged and the treated material is continuously taken out. Further, it is preferable that the treatment tank can be hermetically sealed, but if the boiling point of the organic solvent used is 100 ° C. or higher, the open type will not hinder the work.

(Dispersion step) As a method of charging the raw materials into the above-mentioned processing apparatus, a method of charging all the raw materials at once into the tank, a part of the raw materials are first charged, and the remaining raw materials are charged at a certain stage. And a method of dividing the raw materials or continuously charging the raw materials. It is also possible to add a part of the raw materials in the steps after the dispersion step. In the present invention, any of these methods can basically be adopted. However, the polyester resin supplied in the form of powder, granules or pellets is agitated without stirring, or when heated to a temperature near the glass transition temperature in a state where the agitation speed is not sufficient, the powder, granules or pellets stick to each other to form a lump. No matter how high speed this is stirred, complete hydration will not be achieved,
At least the polyester resin should be charged into the tank during the dispersion process. Other raw materials can be charged into the tank at any stage from the dispersion step to the water-conversion step. However, the compound having a protective colloid action must be dissolved or evenly dispersed in an aqueous medium before the start of aqueous conversion for the purpose of adding the compound. In particular, it is preferable to add a poorly soluble material to the aqueous medium before the dispersion step, or to prepare an aqueous solution of a compound having a protective colloid action in advance, and to add this into the tank.

The polyester resin used in the dispersion step is
It may be in the form of powder or granules, and even if it is in the form of pellets obtained by paying out the polymerization, one side has a diameter of 0.
If it is 8 cm or less, the aqueous treatment can be performed in a sufficiently short time. Of course, the smaller the shape of the polyester resin used for hydration is, the more frequently the polyester resin is contacted with the aqueous medium, and thus the basic compound, so that the time for the hydration step can be shortened. However, the feature of the present invention lies in that the water treatment can be performed in a sufficiently short time even on an industrial scale without making the resin finer than necessary by mechanical pulverization or the like. Considering the energy and time required for atomization such as mechanical pulverization, the shape of the polyester resin used for water solubilization has a side of 0.1 to 0.5 cm, if one side is considered to be a cube. Is 0.15
It is preferably about 0.3 cm.

The dispersing step which is carried out for the purpose of preventing the polyester resin from agglomerating is usually carried out by stirring at room temperature.
You may implement a dispersion process, heating the inside of a tank. At that time, it is necessary to uniformly disperse the polyester resin powder or granules in the aqueous medium until the temperature in the tank reaches 40 ° C. The aqueous medium in the present invention is water or a mixture of water and the organic solvent and / or the basic compound and / or the compound having a protective colloid action. The end point of the dispersion step, that is, the state in which the polyester resin powder or the granular material is uniformly dispersed in the aqueous medium, is described in T. N. Zwiet
ering (Chemical Engineering)
g Science, Vol. 8, p. 244, 1958) defined as "completely suspended state", that is, no particles remain at the bottom of the tank for more than 1-2 seconds. Complete floating stirring speed N to achieve "floating state"
It is preferable to stir above _JS . Usually, the stirring state in the tank can be easily visually determined. The complete floating stirring speed depends on many factors such as the type of stirring blade used, its size and position in the tank, the amount of polyester resin added and its shape, and is determined by tests using actual processing equipment. There must be. Moreover, if the stirring speed in the tank is made higher than N _JS , a certain speed N _SA
With the above, gas entrapment from the free surface begins. Although this phenomenon is eliminated or reduced by a commercially available antifoaming agent, the stirring speed in the tank is preferably in the range of N _{JS to} N _SA . When the inside of the tank reaches this state, it is necessary to maintain this state and immediately proceed to the heating step. If the inside of the tank is heated before the “completely suspended state” is reached, the above agglomeration may occur.

(Heating Step) The heating step is a step of heating the inside of the tank to the temperature required for the water-solubilizing step. If the organic solvent and the basic compound are present in the tank, the resin fine particles have already been added in this step. Formation (waterification) has started. However,
Since the speed is not sufficient, it is preferable to heat the inside of the tank to a predetermined temperature in the shortest possible time. As a method for heating the inside of the tank, there is a method in which a jacket is provided on the tank wall, a spiral coil tube is inserted into the tank, or both are used in combination. Although any method can be adopted in the present invention, it is desirable to reduce the time required for the heating step, make the temperature inside the tank uniform, and control with high accuracy. In addition, during the process, the water-based process progresses too much, and the viscosity of the system may increase abnormally.In such a case, either the organic solvent or the basic compound may be added to the tank during the water-based process. It is possible to solve this problem by putting it inside.

(Aqueousizing step) When the temperature in the tank reaches the glass transition temperature of the polyester resin or 60 ° C., whichever is higher, it is considered in the present invention that the "aqueousizing step" is started. This is not only due to the fact that the hydration of the resin, which progresses even at low temperatures, proceeds at an astonishing rate by heating the inside of the tank above that temperature, but also when hydration proceeds at low temperatures. In some cases, the above-mentioned "abnormal thickening phenomenon of the system" occurs and it becomes impossible to substantially stir the inside of the tank, and the desired water dispersion may not be obtained. Also, from the fact that such a problem does not occur at all when the aqueous treatment is carried out at the temperature or higher, the above-mentioned conditions regarding the temperature in the tank are for obtaining the aqueous dispersion which is the object of the present invention. It should be understood as an important requirement. However, it is preferable that the temperature in the bath is controlled at 90 ° C. or lower. If it exceeds 90 ° C., the evaporation of water becomes remarkable and the agglomeration of the produced polyester resin fine particles may be promoted.

The water-step, the viscosity of the aqueous medium is somewhat increased, the N _SA entrainment of gas from the free surface at a high stirring speed N _'SA than begins. Therefore, N _JS ~
Preferably performed stirring in the range of N _'SA. The stirring speed is N
_If it is less than _JS , the contact area with the aqueous medium of the polyester resin powder or granules, which is becoming water-based, is not sufficient, and the time required for the water-watering process becomes long. On the other hand, even beyond the N _'SA, not only workability problem foaming, the contact area between the aqueous medium by entrainment of the gas is reduced, it takes a long time in an aqueous process. The end point of the water-solubilizing step can be easily judged by the presence or absence of coarse particles by visual observation or touch with a finger, but it is determined by measuring the particle size distribution of the produced polyester resin particles. When the target particle size distribution is reached, the process may proceed to the next cooling step, but the organic solvent may be removed (stripping) out of the system. The hydration step is usually accomplished by continuing stirring for 15-120 minutes according to the conditions described above. If the step is less than 15 minutes, a large amount of coarse particles of the polyester resin remain in the system, while 12
When it exceeds 0 minutes, the polyester resin is hydrolyzed, which is not preferable.

(Cooling Step) This step is a step for cooling the produced water dispersion to room temperature, and may be naturally cooled or may be forcedly cooled by passing a refrigerant through the jacket or coil tube. At that time, only water on the surface of the water dispersion evaporates to form a film having a high solid content concentration, so-called "skinning" is prevented, and the generated water dispersion is inferior in storage stability at higher temperatures. Therefore, the water dispersion was 40 ° C.
It is preferable to stir until cooled below. However, stirring may be for achieving the above purpose,
The speed is preferably N _JS or less. In addition, it is also possible to add and mix other substances as described later in the cooling step.

(Particle Diameter of Polyester Resin Fine Particles) The polyester resin aqueous dispersion prepared by such a method may satisfy one or more of the following conditions (a), (b) and (c). preferable. (A) The volume-based median diameter in the particle size distribution of the polyester resin fine particles dispersed in the aqueous medium is 2 μm.
And the maximum particle size does not exceed 10 μm. (B) The polyester resin fine particles dispersed in the aqueous medium have a mode diameter of 1 μm or less in the distribution located on the finest particle side in the particle size distribution based on volume, and 80% of the polyester resin particles are fine particles. The diameter does not exceed 4 μm. (C) The polyester resin fine particles dispersed in the aqueous medium have a volume-based median diameter of 2 μm or less, and a distribution mode diameter located on the finest particle side is 1 μm or less, and further the following formula ( Satisfies 1). log (90% particle size / 10% particle size) ≦ 1 (1) 1 of (a), (b) and (c) related to the particle size of dispersed particles
It is considered that the excellent storage stability of the aqueous dispersion is exhibited by satisfying one or more conditions.

That is, when the median diameter exceeds 2 μm or the maximum particle diameter exceeds 10 μm, the viscosity of the aqueous dispersion increases remarkably during storage, or , It may cause phase separation. Median diameter is 0.3 to 2 μm, and even 0.3
It is more preferably about 1.8 μm. The maximum particle size is 8 μm or less,
Furthermore, 7 μm or less is more preferable. Further, there is a concern that an aqueous dispersion having a median diameter of less than 0.3 μm is susceptible to hydrolysis.

If the mode diameter of the distribution located on the finest particle side exceeds 1 μm, or if the 80% particle diameter of the polyester resin fine particles exceeds 4 μm, the particle size distribution during storage is The viscosity of the water dispersion may increase significantly or phase separation may occur. The mode diameter is preferably 0.05 to 1 μm, and more preferably 0.08 to 1 μm. The 80% particle size of the polyester resin fine particles is preferably 3.8 μm or less, and more preferably 3.5 μm or less. Further, the water dispersion having a mode diameter of less than 0.05 μm is
There is a concern that it is susceptible to hydrolysis. Where 80%
In the particle size distribution based on the volume of the polyester resin aqueous dispersion, the particle size is 8 with respect to the total integrated particle amount when the particle amounts of each fraction are integrated from the fine particle side.
It is the particle size located at 0%.

Furthermore, when the median diameter exceeds 2 μm, or when the mode diameter of the distribution located on the finest particle side exceeds 1 μm, or when the formula (1) is not satisfied. If it has such a wide particle size distribution, the viscosity of the aqueous dispersion may increase significantly during storage, or phase separation may occur. Median diameter is 0.3 to 2 μm, and further 0.3 to 1.8 μm
Is more preferred. The mode diameter of the distribution located on the finest particle side is preferably 0.05 to 1 μm, more preferably 0.08 to 1 μm. An aqueous dispersion having a median diameter of less than 0.3 μm or a mode diameter of less than 0.05 μm may be susceptible to hydrolysis. Here, in the formula (1), 90%
(Or 10%) particle size means the total particle amount when the particle amounts of each fraction are added from the fine particle side in the particle size distribution of the polyester resin aqueous dispersion on a volume basis. The particle size is located at 90% (or 10%). The spread of the distribution represented by the formula (1) is preferably 0.98 or less, more preferably 0.96 or less.

The particle size distribution is measured without diluting the prepared polyester resin water dispersion, and the agglomeration state of the polyester resin fine particles dispersed in the aqueous medium of the water dispersion is present. The information also includes. The particle size distribution of the polyester resin fine particles dispersed and present in the aqueous medium of the polyester resin aqueous dispersion is measured by a laser diffraction particle size distribution measuring device, for example, SALD-2000 "high concentration measuring system" manufactured by Shimadzu Corporation. It is possible.

In the present invention, in order for the polyester resin water dispersion to have excellent storage stability, it is preferable that the particle size distribution of the polyester resin fine particles in the water dispersion satisfy the predetermined condition. 1, 2 and 3 show typical models of particle size distribution of polyester resin fine particles in an aqueous dispersion. In FIGS. 1A to 1G, (a) and (b) satisfy the condition of (a). That is, the median diameter on a volume basis is 2 μm or less,
Moreover, the maximum particle size does not exceed 10 μm.
On the other hand, as shown in (c), when the particle size of so-called secondary particles generated by aggregation of primary particles is large,
When the proportion of secondary particles is high as in (d) and (g),
When the polyester resin particles are coarse particles as in (e) and (g), and when the particle size distribution is wide as in (f), the storage stability of the polyester resin aqueous dispersion is generally in these cases. Not good.

2 (a) to 2 (g),
(A) and (b) satisfy the above condition (b). That is, in the volume-based particle size distribution of the polyester resin fine particles, the mode diameter of the distribution located on the finest particle side is 1 μm or less, and the 80% particle size does not exceed 4 μm. On the other hand, as in (c),
When the so-called secondary particle size generated by aggregation of primary particles is large, when the proportion of secondary particles is high as in (d) and (g), polyester is used as in (e) and (g). When the resin particles are coarse particles as a whole, or when the particle size distribution is wide as in (f), the storage stability of the polyester resin aqueous dispersion is generally not good in these cases.

Furthermore, in FIGS. 3A to 3G, (a) and (b) satisfy the above condition (c). That is, the volume-based median diameter in the particle size distribution of the polyester resin fine particles is 2 μm or less, and the mode diameter of the distribution located closest to the fine particles is 1 μm.
It is m or less, and further satisfies the above formula (1). On the other hand, when the particle diameter of so-called secondary particles generated by aggregation is large as in (c), when the proportion of secondary particles is high as in (d) and (g), (e) And (g), the polyester resin particles are coarse particles as a whole, and (f) has a wide particle size distribution. In these cases, the storage stability of the polyester resin aqueous dispersion is generally Not good.

From FIG. 1, FIG. 2 and FIG. 3, in the polyester resin aqueous dispersion, not only the particle size distribution as the primary particles of the resin fine particles conventionally considered but also the agglomeration state of the primary particles and the amount thereof are obtained. It can be seen that the storage stability of the water dispersion is greatly affected. Therefore, it is important to control this aggregation state in order to improve the storage stability of the aqueous dispersion.

Although the phenomenon occurring during the above-mentioned aqueous step is not completely understood, the above organic solvent obviously acts as a plasticizer for the polyester resin. In fact, softening of the resin is observed when the system is heated to 60 ° C. or higher under stirring in the absence of the basic compound. However, by using an organic solvent satisfying the above two conditions, the time of the water-conversion step can be remarkably shortened because not only the effect of plasticizing but also the effect of hydrophilizing the surface of the polyester resin powder or the granular material can be achieved. It is also believed that That is, since these compounds have both a hydrophobic structure and a highly polar structure in the molecule,
It is presumed that it can play a role of increasing the frequency of contact between the carboxyl group in the hydrophobic polyester resin and the hydrophilic and highly polar basic compound. Further, since these organic solvents have a structure like a surfactant, even if the organic solvent has a very low molecular weight, it acts as a dispersion stabilizer of the produced aqueous dispersion, and therefore the organic dispersion of the aqueous dispersion is It is understood that storage stability is significantly improved.

In particular, in an aqueous dispersion using the polyester resin (A '), even a high acid-weight polyester resin having a lower acid value can be made water-soluble, and a compound having a protective colloid action can be used. The reason why the storage stability of the obtained aqueous dispersion is excellent even if the added amount is reduced is considered as follows. That is, when the carboxyl group in the polyester resin is present at the end of the molecular chain, by increasing the dispersity of the molecular weight distribution of the polyester resin, substantially lower than the acid value of the resin, a low molecular weight fraction with a high acid value and There will be a high molecular weight fraction with a substantially lower acid number than the acid number of the resin. The former of these is
Since it has a high acid value, it is more hydrophilic, and moreover, it is susceptible to plasticizing action by heat treatment and organic solvent,
The fluidity is also high, and it is considered that the resulting resin fine particles are localized by the surface portion of the resin fine particles. In that case, the concentration of the carboxyl group on the surface portion of the resin fine particles is higher than expected, and therefore, it is considered that the electric repulsive force between the carboxyl anions acts more effectively.

When the polydispersity of the molecular weight distribution of the polyester resin is increased, a large amount of low molecular weight fractions are produced, and as a result, various properties of the coating film formed from the obtained water dispersion may be deteriorated. . In fact, we faced this problem in the process of reaching the present invention. In contrast, the polyester resin has a number average molecular weight of 4,000
It has been found that the performance of the coating film formed is dramatically improved when the value exceeds 0 after reaching 0. Therefore, the number average molecular weight of the polyester resin needs to be 4,000 or more.

In the present invention, by making the polyester resin an aqueous dispersion with a high solid content, it is possible to cope with recent trends in environmental protection, resource conservation, regulation of dangerous substances by the Fire Service Act, and improvement of the working environment. In addition, the water dispersion of this type is often excellent in storage stability, which is often a problem, and it is possible to form a film exhibiting the excellent performance that the polyester resin originally has, and
It is clearly distinguished from the conventional known technique in that it provides a manufacturing method which can be easily carried out by those skilled in the art without requiring a special device or complicated operation.

The polyester resin aqueous dispersion of the present invention can be used in paints, adhesives, inks, fiber treatment agents, paper coating agents and various coating agents. Although the polyester resin aqueous dispersion of the present invention can be used as it is, a high degree of coating performance can be exhibited by blending a curing agent and performing bake curing. As the curing agent, phenol resin, aminoplast resin, polyfunctional epoxy compound,
Examples thereof include polyfunctional isocyanate compounds, various blocked isocyanate compounds thereof, and polyfunctional aziridine compounds. A reaction catalyst and a promoter can also be used in combination if necessary. A pigment, a dye, various additives, and the like can be added to the polyester resin aqueous dispersion of the present invention. In addition, it can be used as a mixture with other aqueous resin.
Furthermore, coating materials, adhesives, inks, fiber treatment agents, paper coating agents and various coating agents using the polyester resin aqueous dispersion of the present invention are dip coating method, brush coating method, roll coating method, spray coating method, A uniform and high-gloss coating can be formed by a gravure coating method, various printing methods, and the like.

[0062]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. In the examples, simply "part" means "part by weight".
Means Each analysis item was performed according to the following method.

(1) Composition of polyester resin It was determined from ¹ H-NMR (manufactured by Varian, 300 MHz). In addition, for resins containing constituent monomers for which no assignable / quantifiable peaks are observed on the ¹ H-NMR spectrum, methanol decomposition was performed in a sealed tube at 230 ° C. for 3 hours, and then subjected to gas chromatogram analysis for quantitative analysis. I went.

(2) Weight average molecular weight, number average molecular weight and relative viscosity of polyester resin As described above, the weight average molecular weight or number average molecular weight of the polyester resin is determined by GPC analysis (Shimadzu Corporation, solvent:
Tetrahydrofuran, UV-visible spectrophotometer, detected by detection wavelength 254 nm, converted to polystyrene). Also, the relative viscosity of polyester resin is phenol /
It was dissolved in an equal weight mixed solvent of 1,1,2,2, -tetrachloroethane at a concentration of 1% by weight and measured at 20 ° C. using an Ubbelohde viscosity tube.

(3) Acid Value of Polyester Resin 1 g of polyester resin is dissolved in 30 ml of chloroform or dimethylformamide (DMF) and titrated with KOH using phenolphthalein as an indicator to obtain the mg of KOH consumed for neutralization. Was calculated as the acid value.

(4) Glass transition temperature of polyester resin Using 10 mg of polyester resin as a sample, DSC (differential scanning calorimetry) device (DS by Perkin Elmer Co., Ltd.)
C7) was used for measurement at a temperature rising rate of 10 ° C./min to obtain the value.

(5) Solid Content Concentration of Water Dispersion An appropriate amount of the prepared water dispersion is weighed, and the weight of the residue (solid content) at a temperature above the boiling point of the organic solvent contained in the water dispersion. Was heated until a constant weight was reached, and the solid content concentration was determined.

(6) Particle Size Distribution of Water Dispersion The water dispersion was sandwiched between two glass preparations without dilution and used as a uniform thin layer for measurement, and a laser diffraction type particle size distribution measuring device ( Shimadzu SAL
D-2000 "high concentration measurement system")
The particle size distribution was measured at ° C. In the calculation process for obtaining the particle size distribution from the obtained light intensity curve, a refractive index of 1.6-0.1i that gives the most appropriate result from the light intensity curve is adopted,
The obtained results were not subjected to any processing such as approximation to the distribution function and smoothing processing. The maximum particle size is
With the upper limit of the maximum particle size fraction in each particle size distribution as the representative value, the mode diameter of the distribution located on the finest particle side is
The central value of the fraction that takes the maximum value of the distribution derived from the finest particle side, that is, from the primary particles was used.

(7) Viscosity of Water Dispersion Cone / plate type rotational viscometer (Rheology Co., Ltd.,
MR-3 liquid meter), shear rate 10se
The viscosity at c ^-1 and 30 ° C was measured. However, in consideration of the thixotropy of the water dispersion, the viscosity at the time when it started to rotate and reached a steady state was determined.

(8) Adhesion to Film and Water Resistance A polyethylene terephthalate (PET) film is coated with an aqueous dispersion and dried to form a coat layer, and then the coat layer is prescribed in JIS Z-1522. Adhesive tape (width: 18 mm) was attached, and the tape was completely adhered by rubbing with an eraser, and the edge of the adhesive tape was peeled off momentarily while keeping it at right angles to the PET film. Then, the adhesive surface of the adhesive tape was subjected to surface infrared spectroscopic analysis (SYSTEM 2000, Ge 60 ° 50 manufactured by Perkin Elmer Co., Ltd.
Then, it was confirmed whether or not the coat layer derived from the water dispersion was transferred to the pressure-sensitive adhesive tape (normal adhesion).

Next, the PET film having the coat layer formed thereon is subjected to retort treatment (115 ° C., 20 min) and 50 ° C.
After drying for 10 minutes in the oven, the surface analysis of the coated surface of the film was carried out in the same manner as above, and it was confirmed whether or not the coating layer remained on the film surface. For the film with the coating layer remaining, the adhesion test was further conducted using the above-mentioned adhesive tape, and this time the surface analysis of both the adhesive surface of the adhesive tape and the coated surface of the film was performed (adhesion after retort treatment. ).

(9) Smoothness of coating film It was visually evaluated.

(10) Gloss of coating film Gloss meter (manufactured by HORIBA, Ltd., Gloss Checker IG-
The reflectance of 60 degrees was measured at 310).

(11) Workability of coating film 10 kg / cm with coated steel sheets such that the coated surface is the outer surface and n sheets of the same thickness are sandwiched in the bent portions.
Bending was performed at a pressure of ² , and cracks generated in the bent portion were observed and judged with a magnifying power of 50 times. "NT" in Tables 6 and 12
Indicates that the minimum number n of the bent portions does not cause cracks even when n pieces having the same plate thickness are sandwiched between the bent portions.

(12) Pencil hardness of coating film The coating surface of a steel plate was measured according to JIS K-5400 using a high-grade pencil defined in JIS S-6006.

(13) Solvent resistance of coating film The coating film was rubbed using a gauze impregnated with xylene, and the number of times of reciprocation until the undercoat appeared was recorded.

(14) Hot water resistance of coating film The coated steel sheet was treated for 1 hour in a hot water bath controlled to a predetermined temperature, and the gloss retention rate (%) represented by the following formula was determined. Gloss retention rate (%) = (Gloss after treatment / Initial gloss) x 1
00

(Production Example of Polyester Resin) Polyester Resin A-1 1,578 g of terephthalic acid, 83 g of isophthalic acid, 374 g of ethylene glycol, 73 of neopentyl glycol
The esterification reaction was carried out by heating a mixture consisting of 0 g in an autoclave at 260 ° C. for 2.5 hours. Next, 0.262 g of germanium dioxide as a catalyst was added, the system temperature was raised to 280 ° C. in 30 minutes, and the system pressure was gradually reduced to 0.1 Torr after 1 hour. The polycondensation reaction is further continued under these conditions, and after 1.5 hours, the system is brought to normal pressure with nitrogen gas, the system temperature is lowered, and when the temperature reaches 260 ° C., 50 g of isophthalic acid and 38 g of trimellitic anhydride are added, The mixture was stirred at 255 ° C. for 30 minutes and discharged in a sheet form. After sufficiently cooling this to room temperature, it was crushed with a crusher and a fraction having a mesh size of 1 to 6 mm was obtained as a polyester resin A-1 using a sieve. Polyester resin A
The analysis results of -1 are shown in Table 1.

Polyester Resins A-2 to A-7 and A-
9 Various polyester resins A-2 to A-7 and A-9 were produced in the same manner as the polyester resin A-1. Table 1 shows the analysis results of each resin.

Polyester resin A-8 1,973 g of terephthalic acid, 104 g of isophthalic acid, 430 g of ethylene glycol, 9 neopentyl glycol
A mixture consisting of 80 g was placed in an autoclave at 260 ° C.
The mixture was heated for 2.5 hours to carry out the esterification reaction. Next, 0.329 g of germanium dioxide was added, the temperature of the system was raised to 280 ° C. in 30 minutes, and then the pressure of the system was gradually reduced to 0.1 Torr after 1 hour. The polycondensation reaction was further continued under these conditions, and after 1.5 hours, the system was returned to normal pressure with nitrogen gas, the temperature of the system was lowered, and when the temperature reached 250 ° C, 52 g of neopentyl glycol was added and 245 ° C was added.
Stirring is continued for 30 minutes, the temperature of the system is further lowered to 200 ° C., 56 g of phthalic anhydride is added and reacted for 10 minutes, and then granular polyester resin A-8 is prepared in the same manner as polyester resin A-1. Obtained. The analysis results of the resin are shown in Table 1.

Alkyd resin A-10 650 g of soybean oil fatty acid, hexahydrophthalic anhydride 1,
010 g, adipic acid 955 g, pentaerythritol 575 g, diethylene glycol 2,020 g, polyethylene glycol (manufactured by Sanyo Chemical Industry Co., Ltd., PEG60)
00S) 795 g, refluxing xylene 200 g and dibutyltin oxide 8.5 g as a catalyst in an autoclave at 200 to 210 ° C. with an acid value of 10 mg.
Heated to KOH / g. Then, 215 g of trimellitic anhydride was added and reacted for 10 minutes under a nitrogen atmosphere to obtain an alkyd resin A-10 having the same shape as the polyester resin A-1. As a result of analysis, the acid value of the resin was 20.5 mgKOH / g, and the weight average molecular weight was 9,
The glass transition temperature was 400, the relative viscosity was 1.30, and the glass transition temperature was not clearly observed, but it softened when heated to 60 ° C.

Example 1 In a 2 L glass container with a jacket, 200 g of polyester resin A-1, 35 g of ethylene glycol-n-butyl ether, polyvinyl alcohol (Unitika Ltd.) were used.
"Unitika Poval" 050G) 0.5% by weight aqueous solution (hereinafter, PVA-1) 459 g and N, N-dimethylethanolamine (hereinafter, referred to as 1.2 times equivalent to the total amount of carboxyl groups contained in the polyester resin) , DME
A) was charged, and this was stirred in an open system using a tabletop homodisper (TK Robomix manufactured by Tokushu Kika Kogyo Co., Ltd.) at 6,000 rpm. It was not observed, and it was confirmed to be in a completely floating state. Therefore, maintaining this state, hot water was passed through the jacket after 10 minutes to heat the jacket. Then, when the temperature inside the container reached 68 ° C., the stirring was adjusted to 7,000 rpm, the temperature inside the container was maintained at 68 to 70 ° C., and the stirring was continued for 20 minutes to obtain a milky white uniform aqueous dispersion. Then, cold water was poured into the jacket, the mixture was cooled to room temperature while stirring at 3500 rpm, and filtered using a stainless steel filter (635 mesh, plain weave). As a result, almost no resin particles remained on the filter. Table 2 shows the analysis results of the obtained filtrate (aqueous dispersion B-1).

Examples 2 to 6 In the same manner as in Example 1, various materials were used to try to make them aqueous. Table 2 shows the analysis results of the obtained water dispersion.

Comparative Examples 1 to 5 In the same manner as in Example 1, various materials were used to try to make them aqueous. Table 3 shows the analysis results of the obtained water dispersion.

Comparative Example 6 200 g of polyester resin A-1 was tried to be dissolved in tetrahydrofuran, but the resin was not dissolved even when refluxed in 800 g of tetrahydrofuran. Next, the same operation was performed using methyl ethyl ketone, but it did not dissolve. Therefore, the resin was replaced with tetrahydrofuran 200
64-6 in a mixed solvent of 100 g of cyclohexanone
Upon stirring at 5 ° C., a uniform solution was obtained. This is 6
Keep at 0 ° C and use the above-mentioned tabletop homodisper
Same amount of DMEA as in Example 1 while stirring at 00 rpm
An attempt was made to carry out phase inversion emulsification by dropping a mixture of 100 g of PVA-1 and 600 g of PVA-1 at a rate of 10 g / min.

Comparative Example 7 200 g of polyester resin A-2 was stirred at 64-65 ° C. in a mixed solvent of 200 g of tetrahydrofuran and 100 g of ethylene glycol-n-butyl ether to obtain a uniform solution. This was stirred at 7,000 rpm using the tabletop homodisper, and the total amount of carboxyl groups contained in the polyester resin was 1.
600 g of DMEA and PVA-1 equivalent to double equivalent
The mixture was added dropwise to the mixture at a rate of 30 g / min, and stirring was continued at room temperature for 30 minutes to obtain a uniform aqueous dispersion.
This was further stirred in a hot water bath at 80 ° C. at 7,000 rpm to try to remove tetrahydrofuran out of the system, but aggregation occurred before the smell of tetrahydrofuran disappeared, and a white lump was formed. Instead of PVA-1, a 4 wt% aqueous solution of the polyvinyl alcohol (hereinafter, PVA-3)
Was used with similar results.

Example 7 and Comparative Example 8 Monoethanolamine (hereinafter referred to as ME
Under the same conditions as in Example 1 except that A) was used, stirring was performed at room temperature at 6,000 rpm for 10 minutes, and thereafter,
When stirring was performed at 7,000 rpm, the temperature in the system gradually increased, and when the temperature reached 42 ° C, the system remarkably thickened and it became impossible to carry out further stirring treatment. (Comparative Example 8). Therefore, a raw material other than ethylene glycol-n-butyl ether was charged, the dispersion and heating steps were performed under the same conditions as in Example 1, and ethylene glycol-n-butyl ether was added at 7 g / m 2 when the temperature in the system reached 68 ° C.
The mixture was added dropwise at a rate of in, and further stirred at 68 to 70 ° C. for 25 minutes, cooled, and filtered to obtain an aqueous dispersion B-12 (Example 7). Table 2 shows the analysis results of the obtained water dispersion B-12.

Example 8 and Comparative Example 9 In a 2 L glass container with a jacket, 200 g of polyester resin A-4, 45 g of ethylene glycol-n-butyl ether, 470 g of PVA-1 and the total amount of carboxyl groups contained in the polyester resin were added. DMEA corresponding to 1.3 times equivalent was charged, and this was stirred at 6,000 rpm using a tabletop homodisper, and after 10 minutes, hot water was passed through the jacket to heat it. And when the temperature inside the container reached 52 ° C, the stirring was changed to 7,000 rpm,
When the temperature in the container was kept at 52 to 55 ° C. and further stirring was performed, the presence of coarse particles was visually and visually observed even after 60 minutes (Comparative Example 9). Therefore, the hydration process should be 63-6.
An attempt was made to aqueousize under the same conditions except that the operation was carried out at 6 ° C. for 28 minutes, whereby a milky white uniform aqueous dispersion B-13 was obtained (Example 8). Table 2 shows the results of the analysis.

Comparative Example 10 The same raw material as in Example 1 was charged into a jacketed 2 L glass container and stirred at 3,000 rpm using the above-mentioned tabletop homodisper. It is in a state to generate. Then, when this was heated in the same manner as in Example 1, the system temperature was 60
When the temperature reached ℃, the precipitation of the resin granules at the bottom of the container softened and became a uniform transparent lump. Therefore, agitate 7.0
Although the system temperature was heated to 70 to 73 ° C. at 00 rpm, this lump did not disappear even after 30 minutes.

Comparative Example 11 An aqueous solution was tried under the same conditions as in Example 1 except that the polyester resin A-8 was used. However, the presence of coarse particles was visually observed even after stirring at 68 to 70 ° C. for 40 minutes.

Comparative Examples 12 to 13 Example 1 was repeated except that 50 g of methanol, which was amphipathic but did not have plasticizing ability for the polyester resin A-1, was used in place of ethylene glycol-n-butyl ether. An attempt was made to make it aqueous under the same conditions. However, even when the aqueous step was carried out for 20 minutes, there was almost no change in the system, and no change in the appearance of the resin granules was observed (Comparative Example 12). On the other hand, when 50 g of xylene, which has a plasticizing ability with respect to the polyester resin A-1, but is not amphiphilic, is used as an organic solvent, the presence of coarse particles can be visually confirmed even after the water-conversion step is carried out for 40 minutes. Observed (Comparative Example 13).

Example 9 Aqueous solution was obtained under the same conditions as in Comparative Example 2 except that ethylene glycol-n-butyl ether was used. As a result, a milky white uniform aqueous dispersion was obtained. This water dispersion B-14
Table 2 shows the results of analysis.

Example 10 and Comparative Examples 14 to 15 (Production of Water Dispersion B-15) Aqueousization was carried out under the same conditions as in Example 1 except that the polyester resin A-6 was used. Table 4 shows the analysis results of the obtained water dispersion B-15.

(Adhesion to film and water resistance) After production, the aqueous dispersion stored at room temperature within 1 week was dried with a film applicator No 542-AB (Bar coater) manufactured by Yasuda Seiki Co., Ltd. It was applied to a commercially available biaxially stretched PET film (thickness 15 μm) so that the thickness was 3 μm. Then, this was dried at 60 ° C. for 5 minutes and subsequently at 150 ° C. for 2 minutes, and the adhesiveness between the coat layer and the PET film and the water resistance of the coat layer in the normal state and after the retort treatment were evaluated. Table 5 shows the results.

Example 11 2 parts of melamine resin (CYMEL 325 manufactured by Mitsui Cyanamid Co., Ltd.) was added to 80 parts of the solid content of the water dispersion B-1.
0 parts, titanium oxide (Ishihara Sangyo Co., Ltd., Taipaek CR)
A mixture of 100 parts of -50) and 250 parts of glass beads was shaken and dispersed in a paint shaker for 1 hour. Then, this is bonded to a steel plate (Japan Test Panel Osaka Co., Ltd.)
(0.8 x 70 x 150 mm) and 1 at 70 ° C
After preliminary drying for 15 minutes, baking was performed at 150 ° C. for 20 minutes to obtain a cured coating film having a film thickness of about 25 μm. The performance of the obtained cured coating film is shown in Table 6. When evaluating the hot water resistance of the coating film in the table, the coated steel sheet was treated in a hot water bath at 60 ° C.

Example 12 and Comparative Example 16 (Production of Water Dispersion B-16) Aqueousization was carried out under the same conditions as in Example 1 except that polyester resin A-7 was used.
Table 4 shows the analysis results of the obtained water dispersion B-16. A coating material and a cured coating film were obtained in the same manner as in Example 11 except that various water dispersions were used instead of the water dispersion B-1. The performance of the obtained cured coating film is shown in Table 6.

Examples 13 to 14 and Comparative Example 17 (Production of Water Dispersions B-17 to 19) Polyester Resin A
-5 (water dispersion B-17), A-9 (water dispersion B-1)
8) and alkyd resin A-10 (aqueous dispersion B-19)
Aqueous treatment was carried out under the same conditions as in Example 1 except that
Table 7 shows the analysis results of the obtained water dispersion. Water dispersion B
A coating material and a cured coating film were obtained in the same manner as in Example 11 except that various water dispersions were used instead of -1. The performance of the obtained cured coating film is shown in Table 6.

[0098]

[Table 1]

[0099]

[Table 2]

[0100]

[Table 3]

However, in Tables 2 and 3, a) charged amount is 200 g b) DMEA: N, N-dimethylethanolamine, M
EA: monoethanolamine, TEA: triethylamine c) Bu-EG: ethylene glycol mono-n-butyl ether, Bu-PG: propylene glycol mono-n
-Butyl ether, Anone: Cyclohexanone, Et-
EG: ethylene glycol monoethyl ether d) PVA-1: manufactured by Unitika Ltd., 0.5% by weight aqueous solution of “Unitika Poval” 050G, PVA-2: manufactured by Unitika Ltd., “Unitika Poval” 180G of 0. 5
Wt% aqueous solution, PVA-3: manufactured by Unitika Ltd., 4 wt% aqueous solution of “Unitika Poval” 050G, HEC: hydroxyethyl cellulose (Daicel Chemical Industries Ltd.)
Manufactured by HEC Daicel SP600) 0.5% by weight aqueous solution, PIA: polyitaconic acid (Iwata Chemical Co., Ltd.)
Manufactured by PIA-728) 0.5% by weight aqueous solution e) Mode diameter of distribution located on the finest particle side f) log (90% particle size / 10% particle size)

[0102]

[Table 4]

[0103]

[Table 5]

[0104]

[Table 6]

[0105]

[Table 7]

(Production Example of Polyester Resin) Polyester Resin A′-1 15.78 kg of terephthalic acid, 0.83 k of isophthalic acid
A mixture of g, 3.74 kg of ethylene glycol and 7.30 kg of neopentyl glycol was heated in an autoclave at 260 ° C. for 2.5 hours to carry out an esterification reaction. Then 2.6 using germanium dioxide as a catalyst
2 g was added, the system temperature was raised to 280 ° C. in 30 minutes, and the system pressure was gradually reduced to 0.1 Torr one hour later. The polycondensation reaction is further continued under these conditions, and after 1.5 hours, the system is brought to normal pressure with nitrogen gas, and the system temperature is lowered to 270
When the temperature reached ° C, 500 g of isophthalic acid and 380 g of trimellitic acid anhydride were added, and the mixture was stirred at 265 ° C for 15 minutes and discharged in a sheet form. After sufficiently cooling this to room temperature, it was crushed with a crusher and a fraction having a mesh size of 1 to 6 mm was obtained as a polyester resin A'-1 using a sieve. Table 8 shows the analysis results of the polyester resin A'-1.

Polyester Resins A'-2 to A'-5 Various polyester resins A'-2 to A'-5 were produced by the same method and conditions as the polyester resin A'-1. Table 8 shows the analysis results of each resin.

Polyester resin A'-6 terephthalic acid 4.984 kg, ethylene glycol 1.
A mixture of 210 kg and neopentyl glycol 1.875 kg was autoclaved at 2.5 ° C. for 2.5 hours.
The esterification reaction was performed by heating for a time. Next, 0.838 g of germanium dioxide as a catalyst was added, the system temperature was raised to 280 ° C. in 30 minutes, and the system pressure was gradually reduced to 0.1 Torr after 1 hour. The polycondensation reaction was further continued under these conditions, and after 1.5 hours, the system was adjusted to normal pressure to increased pressure with nitrogen gas, discharged in a strand form, cooled with water, and then cut into chips. After sufficiently drying the obtained resin chip,
Trimellitic anhydride 18.2 per 1 kg of the chips
g was dry blended and extruded at 270 ° C. using a vented biaxial kneader (PCM-45, manufactured by Ikegai Iron Works Co., Ltd.) to obtain a sheet. At the time of extrusion, the vent hole was kept under a reduced pressure of 50 Torr or less to capture the sublimate and distillate. Then, after sufficiently cooling the sheet material to room temperature, it is crushed with a crusher and opened with a sieve 1
A ˜6 mm fraction was obtained as polyester resin A′-6. Table 8 shows the analysis results of the polyester resin A'-6.

Polyester resin A'-7 terephthalic acid 2.373 kg, ethylene glycol 39
A mixture of 0 g and 1.265 kg of neopentyl glycol was heated in an autoclave at 260 ° C. for 2.5 hours to carry out an esterification reaction. Then 0.405 g of germanium dioxide was added, and the system temperature was 280 in 30 minutes.
The temperature was raised to 0 ° C., and then the system pressure was gradually reduced to 0.1 Torr after 1 hour. The polycondensation reaction is further continued under these conditions, and after 1.5 hours, the system is returned to normal pressure with nitrogen gas,
When the temperature of the system was lowered to 250 ° C., 27.4 g of trimellitic anhydride was added, stirring was continued at 245 ° C. for 10 minutes (first stage depolymerization), and the system was further cooled to 210 ° C. , 2-bis (4-hydroxyethoxyphenyl) propane (45.2 g) was added and reacted for 20 minutes (second stage depolymerization). And polyester resin A '
A granular polyester resin A′-7 was obtained in the same manner as in -1. The analysis results of the resin are shown in Table 8.

Polyester Resins A'-8 and A'-9 In the same manner as polyester resin A'-7, acid anhydride was added to carry out the first stage depolymerization, and then a polyhydric alcohol component was added. The second stage depolymerization was carried out to produce polyester resins A′-8 and A′-9. Table 8 shows the type of depolymerizing agent, the addition amount, and the analysis result of each resin.

Polyester resins A'-10 and A'-1
265 by adding isophthalic acid and trimellitic anhydride
The depolymerization process performed at ℃ for 30 minutes (polyester resin A '
-10), or 10 minutes (polyester resin A'-1
Polyester resins A'-10 and A'-11 were produced under the same conditions as the polyester resin A'-1 except that it was 1). Table 8 shows the analysis results of each resin.

Polyester resin A'-12 Isophthalic acid and trimellitic anhydride were added to obtain 265
Polyester resin A'- under the same conditions as polyester resin A'-2 except that the depolymerization step carried out at 30 ° C was 30 minutes.
12 was produced. Table 8 shows the analysis results of the obtained resin.

Polyester resin A'-13 Polyester resin A'-11 1 kg of an epoxy compound (Nagase Kasei Kogyo KK, Denacol EX-7)
11) 18 g and triphenylphosphine 1 g were dry blended, and the vented biaxial kneader (30 Tor)
It was extruded into a sheet at 200 ° C. using a reduced pressure condition of r or less). Then, after sufficiently cooling this sheet material to room temperature, it is crushed by a crusher, and a sieve is used to open 1 to 6 m.
A fraction of m was obtained as polyester resin A′-13. As a result of analysis, the acid value of the resin was 18.6 mgKOH / g, the number average molecular weight was 6,800, the dispersity was 7.4, and the glass transition temperature was 65 ° C.

Example 15 Using a tabletop homodisper (TK Robomix manufactured by Tokushu Kika Kogyo Co., Ltd.) equipped with a 2L glass container with a jacket and being in a sealed state when mounted, polyester resin was used for the glass container. A′-1 300 g, n-butanol 50 g, polyvinyl alcohol (manufactured by Unitika Ltd., “Unitika Poval” 050 G. Below, PV
Abbreviated as A) 150 g of 0.1 wt% aqueous solution and pure water 490
g, and N, N-dimethylethanolamine (hereinafter, DMEA) corresponding to 1.2 times equivalent of the total amount of carboxyl groups contained in the polyester resin were charged, and the mixture was stirred at room temperature at 6,000 rpm, and the bottom of the container was stirred. After confirming that no precipitation of the resin granules was observed in 10 minutes, hot water was passed through the jacket and heated 10 minutes later. And the temperature inside the container is 6
When the temperature reached 8 ° C, the stirring was adjusted to 7,000 rpm, the temperature inside the container was maintained at 70 to 72 ° C, and the stirring was continued for 20 minutes.
A milky white uniform aqueous dispersion was obtained. Then, cold water was poured into the jacket, the mixture was cooled to room temperature while stirring at 3500 rpm, and filtered using a stainless steel filter (635 mesh, plain weave). As a result, almost no resin particles remained on the filter. Table 9 shows the analysis results of the obtained filtrate (aqueous dispersion B'-1).

Examples 16 to 27 and Comparative Examples 18 to 19 An aqueous solution was tried under the same conditions as in Example 15 except that the type and the addition amount of the polyester resin and the compound having a protective colloid action were changed. Table 9 shows the analysis results of the obtained water dispersion. In addition, in Examples 15, 18, and 22, although the amount of n-butanol added was reduced to 30 g, it was not confirmed whether or not it was made water-soluble and that the obtained aqueous dispersion was inferior in characteristics.

Comparative Example 20 An aqueous solution was tried under the same conditions as in Example 15 except that the polyester resin A'-9 was used, but the temperature inside the container was 70 to 72.
Most of the resin particles remained in the system even if the mixture was kept at ℃ and stirred for 40 minutes.

Comparative Example 21 Example 16 except that the polyester resin A'-10 was used.
However, when the temperature in the container reached 68 ° C., a lump of resin was formed in the system, and it became difficult to continue stirring.

Examples 28 to 32 and Comparative Examples 22 to 25 (Production of water dispersions B'-16 to 19) An attempt was made to make it aqueous under the same conditions.
Table 10 shows the analysis results of the obtained water dispersions B'-16 to 19.
Shown in

(Adhesion to film and water resistance) After production, the aqueous dispersion stored at room temperature within 1 week was dried using a film applicator No 542-AB (Bar coater) manufactured by Yasuda Seiki Co., Ltd. It was applied to a commercially available biaxially stretched PET film (thickness 15 μm) so that the thickness was 3 μm. Then, this was dried at 60 ° C. for 5 minutes and subsequently at 150 ° C. for 2 minutes, and the adhesiveness between the coat layer and the PET film and the water resistance of the coat layer in the normal state and after the retort treatment were evaluated. Table 11 shows the results.
Shown in

Example 33 1 part of melamine resin (manufactured by Mitsui Cyanamid Co., Ltd., Cymel 325) was added to 85 parts of the solid content of the aqueous dispersion B'-4.
5 parts were added with stirring and stirring was continued for 30 minutes at room temperature. Then, this was commercial tin-free steel (0.
(2 mm thick) and then baked at 170 ° C. for 10 minutes to obtain a cured coating film having a film thickness of about 15 μm. Table 12 shows the performance of the obtained cured coating film. When evaluating the hot water resistance of the coating film in the table, the coated steel sheet was treated in a hot water bath at 80 ° C.

Examples 34 to 37 and Comparative Examples 26 to 28 Paints and cured coating films were obtained in the same manner as in Example 33 except that various water dispersions were used instead of the water dispersion B'-4. Table 12 shows the performance of the obtained cured coating film.

[0122]

[Table 8]

[0123]

[Table 9]

[0124]

[Table 10]

However, in Tables 9 and 10, a) HEC is hydroxyethyl cellulose (manufactured by Daicel Chemical Industries, Ltd., "HEC Daicel" SP800), PI.
A is polyitaconic acid (manufactured by Iwata Chemical Co., Ltd., PIA-
728), and the numbers in the table represent the amount added to the polyester resin in the unit of% by weight. b) Mode diameter of the distribution located on the side of the finest particles c) Value of log (90% particle size / 10% particle size)

[0126]

[Table 11]

[0127]

[Table 12]

Comparative Examples 22 to 28 are given to compare that the coating films obtained from the polyester resin water dispersion, which is an invention capable of solving the third problem, have more excellent water resistance and the like. However, these are within the scope of the polyester resin aqueous dispersion, which is the invention capable of solving the first problem.

[0129]

The polyester resin aqueous dispersion of the present invention comprises
1) The polyester resin does not contain any special monomer components, structures in which ionic groups remain even after the film is dried, and structures that are easily hydrolyzed. 2) Externally added surfactants such as surfactants. It does not contain low molecular weight hydrophilic compounds, and the content of organic solvent is sufficiently reduced. 3) Extremely excellent storage stability even at high solid content concentration. 4) Excellent film forming property. The film formed from the polyester resin aqueous dispersion exhibits excellent processability, water resistance, corrosion resistance, chemical resistance, weather resistance, adhesion to various substrates, and the like. Further, in particular, by increasing the dispersity of the molecular weight distribution of the polyester resin, limiting the acid value, or not containing any compound having a protective colloid action, or the addition amount was extremely small, the polyester resin aqueous dispersion, In addition to the above features, the resulting coating has more excellent water resistance. Therefore, the polyester resin aqueous dispersion of the present invention can be widely used as a binder component for paints, adhesives, inks, fiber treatment agents, paper coating agents and various coating agents.
Further, according to the production method of the present invention, such a polyester resin water dispersion can be easily produced without requiring special equipment or complicated operations.

[Brief description of drawings]

FIG. 1 is a view showing a typical model of particle size distribution of polyester resin fine particles in an aqueous dispersion.

FIG. 2 is a view showing a typical model of particle size distribution of polyester resin fine particles in an aqueous dispersion.

FIG. 3 is a view showing a typical model of particle size distribution of polyester resin fine particles in an aqueous dispersion.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shizuka Xu, 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika Research Institute Central Research Laboratory (72) Inventor Kiyomi Hata, 23 Uji Kozakura, Uji City, Kyoto Unitika Stock Company Central Research In-house

Claims (16)

[Claims] 1. The following (A), (B), (C) and (D)
A polyester resin aqueous dispersion containing components, wherein the polyester resin fine particles are uniformly dispersed in an aqueous medium. (A) Polyester resin substantially composed of polybasic acid and polyhydric alcohol, having an acid value of 10 to 40 mgKOH / g and a weight average molecular weight of 9,000 or more or a relative viscosity of 1.20 or more (B) ) Basic compound (C) 0.5 to 10% by weight of an amphipathic organic solvent having a plasticizing ability for a polyester resin with respect to a polyester resin aqueous dispersion (D) A compound having a protective colloid action is a polyester 0.01 to 3% by weight of resin 2. The volume average median diameter of the polyester resin fine particles dispersed in the aqueous medium is 2 μm or less, and the maximum particle diameter does not exceed 10 μm. Polyester resin water dispersion. 3. In the volume-based particle size distribution of polyester resin fine particles dispersed in an aqueous medium, the mode diameter of the distribution located on the finest particle side is 1 μm or less, and the 80% particle size is 4 μm. The polyester resin water dispersion according to claim 1, which does not exceed the above. 4. The polyester resin fine particles dispersed in an aqueous medium have a volume-based median diameter of 2 μm or less in the particle size distribution, and a mode diameter of the distribution located on the finest particle side is 1 μm or less. The polyester resin water dispersion according to claim 1, which further satisfies the following formula (1) log (90% particle size / 10% particle size) ≦ 1 (1). 5. The polybasic acid component constituting the polyester resin, 50 mol% or more of which is an aromatic polybasic acid, and the polyhydric alcohol component is mainly ethylene glycol and / or neopentyl glycol. Polyester resin water dispersion. 6. The terephthalic acid accounts for 65 mol% or more of the polybasic acid component constituting the polyester resin.
The polyester resin water dispersion described. 7. The polyester resin aqueous dispersion according to claim 1, wherein the amphipathic organic solvent having a plasticizing ability with respect to the polyester resin satisfies the following conditions. (1) The molecule has a hydrophobic structure in which four or more carbon atoms are directly bonded. (2) A molecule having a substituent containing at least one atom having a Pauling electronegativity of 3.0 or more, at the terminal of the molecule, and an atom having an electronegativity of 3.0 or more in the substituent. The chemical shift of the ¹³ C-NMR (nuclear magnetic resonance) spectrum of a carbon atom directly bonded is room temperature, CDCl ₃
Have polar substituents such that when measured in 8. A dispersion step, a heating step, an aqueous step and a cooling step, wherein in the dispersion step, all of the polyester resin shown in (A) below and (B) and (C) are stirred.
And (D) coarsely disperse all or part of the components shown in (D) in an aqueous medium, and in the heating step and the hydration step, the remaining components are added with stirring, or while being added, at 60 ° C. and a glass of polyester resin. Higher transition temperature ~ 9
A method for producing a polyester resin aqueous dispersion, which comprises heating to 0 ° C. and continuously stirring at this temperature for 15 to 120 minutes. (A) Polyester resin substantially composed of polybasic acid and polyhydric alcohol, having an acid value of 10 to 40 mgKOH / g and a weight average molecular weight of 9,000 or more or a relative viscosity of 1.20 or more (B) ) Basic compound (C) 0.5 to 10% by weight of an amphipathic organic solvent having a plasticizing ability for a polyester resin with respect to a polyester resin aqueous dispersion (D) A compound having a protective colloid action is a polyester 0.01 to 3% by weight of resin 9. A polyester resin water dispersion containing the following components (A ′), (B), (C) and (D ′), wherein the polyester resin fine particles are uniformly dispersed in an aqueous medium. A polyester resin water dispersion characterized in that. (A ') is substantially composed of a polybasic acid and a polyhydric alcohol, has an acid value of 8 to 36 mgKOH / g, a number average molecular weight of 4,000 or more, and a dispersity of the molecular weight distribution of 4.
0 or more polyester resin (B) basic compound (C) 0.5 to 10 wt% of an amphipathic organic solvent having a plasticizing ability to the polyester resin with respect to the polyester resin aqueous dispersion (D ' ) 0.05% by weight or less of a compound having a protective colloid action with respect to the polyester resin 10. The median diameter on a volume basis in the particle size distribution of polyester resin fine particles dispersed in an aqueous medium is 2 μm or less, and the maximum particle size does not exceed 10 μm. Polyester resin water dispersion. 11. In the volume-based particle size distribution of polyester resin fine particles dispersed in an aqueous medium, the mode diameter of the distribution located closest to the finest particles is 1 μm or less, and the 80% particle size is 4 μm. The polyester resin water dispersion according to claim 9, which does not exceed the above. 12. The volume-based median diameter in the particle size distribution of polyester resin fine particles dispersed in an aqueous medium is 2 μm or less, and the mode diameter of the distribution located on the finest particle side is 1 μm or less. The polyester resin water dispersion according to claim 9, which further satisfies the following formula (1) log (90% particle size / 10% particle size) ≦ 1 (1). 13. The polybasic acid component constituting the polyester resin, wherein 50 mol% or more is an aromatic polybasic acid, and the polyhydric alcohol component is mainly ethylene glycol and / or neopentyl glycol. Polyester resin water dispersion. 14. The terephthalic acid accounts for 65 mol% or more of the polybasic acid component constituting the polyester resin.
13. A polyester resin aqueous dispersion according to 13. 15. The polyester resin aqueous dispersion according to claim 9, wherein the amphipathic organic solvent having a plasticizing ability for the polyester resin satisfies the following conditions. (1) The molecule has a hydrophobic structure in which four or more carbon atoms are directly bonded. (2) A molecule having a substituent containing at least one atom having a Pauling electronegativity of 3.0 or more, at the terminal of the molecule, and an atom having an electronegativity of 3.0 or more in the substituent. The chemical shift of the ¹³ C-NMR (nuclear magnetic resonance) spectrum of a carbon atom directly bonded is room temperature, CDCl ₃
Have polar substituents such that when measured in 50 ppm or more. 16. A dispersion step, a heating step, an aqueous step and a cooling step, wherein in the dispersion step, all of the polyester resin shown in the following (A ′) and (B), with stirring:
All or part of the components shown in (C) and (D ′) are roughly dispersed in an aqueous medium, and in the heating step and the hydration step,
Add the remaining ingredients under stirring, or while adding,
And a higher temperature of the glass transition temperatures of the polyester resin to 90 ° C., and continuously stirring at this temperature for 15 to 120 minutes, the method for producing a polyester resin aqueous dispersion. (A ') is substantially composed of a polybasic acid and a polyhydric alcohol, has an acid value of 8 to 36 mgKOH / g, a number average molecular weight of 4,000 or more, and a dispersity of the molecular weight distribution of 4.
0 or more polyester resin (B) basic compound (C) 0.5 to 10 wt% of an amphipathic organic solvent having a plasticizing ability to the polyester resin with respect to the polyester resin aqueous dispersion (D ' ) 0.05% by weight or less of a compound having a protective colloid action with respect to the polyester resin