JPH08245769A - Production of aqueous dispersing element of polyester resin - Google Patents

Abstract

PURPOSE: To obtain the subject aqueous dispersing element capable of forming a film excellent in water resistance, etc., and having good hydrolysis resistance in storing a water dispersing element. CONSTITUTION: This method for producing an aqueous dispersing element of polyester resin comprises dissolving and dispersing a polyester resin composed of a polycarboxylic acid component containing >=40mol% of an aromatic dicarboxylic acid containing 2-10mol% of an aromatic dicarboxylic acid in which a group expressed by the general formula SO3 M (M is hydrogen atom or a metal atom) is bonded to aromatic nuclei and a polyol component and having 0.5-10KOHmg/g acid value into water in the presence of a basic substance at >=100 deg.C. The resultant polyester resin aqueous dispersing element is readily obtained without entirely using an organic solvent and has good storage stability and is obtained by dispersing into water using a smaller hydrophilic group amount compared with a conventional method.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel and useful method for producing an aqueous dispersion of polyester resin. More specifically, the present invention relates to a polycarboxylic acid component mainly composed of an aromatic dicarboxylic acid containing a specific amount of an aromatic dicarboxylic acid having a sulfonic acid group or a metal sulfonate group bonded to an aromatic nucleus, and a polyol. And a polyester resin having a specific acid value and dissolved in water in the presence of a basic substance and at a temperature of 100 ° C. or higher, or dispersed. In particular, the present invention relates to a method for producing an aqueous dispersion of polyester resin, which has good storage stability and can form a film having excellent water resistance.

[0002]

2. Description of the Related Art Up to now, among the methods for obtaining an aqueous dispersion of a polyester resin, the method of using an organic solvent includes (1) dissolving a water-dispersible polyester resin in an organic solvent and stirring water It is a method of obtaining a polyester resin aqueous dispersion by adding,
(2) A method of dissolving and dispersing a water-dispersible polyester resin in a mixture of an organic solvent and water is known, and these methods include, for example, a boiling point of 60.
There is known a method (Japanese Patent Publication No. 61-58092) of using an organic solvent having a solubility of 20 g (g) or more in 1 liter of water at 20 ° C. to 200 ° C.

Further, (3) using an organic solvent,
Once a polyester resin aqueous dispersion containing an organic solvent is produced, the organic solvent is distilled off under normal pressure or reduced pressure from the aqueous dispersion to obtain a substantially solvent-free form. A method of producing an aqueous dispersion of polyester resin (Japanese Patent Publication No. 64-10547) is also known.

Further, as a method for obtaining a polyester resin water dispersion using only water without using an organic solvent, (4) pulverized products of a water-dispersible polyester resin, etc., can be used in water or hot water. The method is to dissolve or disperse by stirring in the inside, or (5)
A method is known in which a water-dispersible polyester resin is heated and melted to be mixed with water.

[0005]

However, in the case of using the method of producing the polyester resin aqueous dispersion in the form of using the organic solvent, the flammable organic solvent must be used in the production process. Not only there is a problem in the safety of the shape including the working environment, but the obtained polyester resin aqueous dispersion itself is flammable and therefore flammable, and the polyester resin aqueous dispersion is used. At times, there are various drawbacks, such as volatilization of these organic solvents, which leads to environmental pollution.

Further, when a method of producing a polyester resin aqueous dispersion containing an organic solvent and then distilling the organic solvent from the aqueous dispersion is used, it is inevitable that the organic solvent will be peeled off. However, it has various drawbacks such as low productivity due to the formation of aggregates, and the use of the low boiling point and highly flammable organic solvent itself is limited.

On the other hand, in order to obtain an aqueous dispersion of such a polyester resin using only water as a medium, a polyester resin having both a sulfonic acid group or a sulfonate group and a nonionic hydrophilic group is dissolved in water. A method of dissolving or dispersing is known (Japanese Patent Publication No. 47).
See, for example, -40873. )

However, the polyester resin water dispersion obtained by such a method has insufficient stability, and it is difficult to obtain, for example, a so-called high solid content water dispersion of 30% by weight or more. Not only that,
Moreover, even if the solid content is low, in order to ensure a high degree of stability, the water-dispersible polyester resin is
It is necessary to increase the introduction amount of the hydrophilic group, and in particular, there are drawbacks such as poor water resistance.

Further, as a method of heating and melting the water-dispersible polyester resin and mixing it with water, a method of obtaining an alkyd resin water dispersion by pouring water into the alkyd resin in a molten state (JP-A-57). -16
No. 2722), a high molecular weight water-dispersible polyester resin having excellent water resistance has a high melt viscosity under the temperature conditions as described in the present invention, resulting in fluidization. It is difficult to apply from the viewpoint of properties, and has a drawback that hydrolysis of ester bond occurs at a high temperature at which sufficient fluidity is obtained.

However, as long as the conventional techniques are followed, the inventors of the present invention must have a very high storage stability, and in particular, a polyester having a very high practicality of forming a film excellent in water resistance and the like. It has come to the conclusion that producing resinous water dispersions is very difficult.

Therefore, the problem to be solved by the present invention is, in part, that the storage stability is good, and in addition, in particular, a film excellent in water resistance is formed. That is, it is to provide a polyester resin water dispersion having extremely high practicality.

[0012]

Means for Solving the Problems Accordingly, the present inventors have:
In view of the existence of various drawbacks in the above-mentioned prior art, in order to eliminate such various drawbacks, the aim of the invention as described above, focusing on the problem to be solved, the result of earnest and repeated studies , Where the general formula

[0013]

[Chemical formula 1] -SO ₃ M [I]

(However, M in the formula represents a hydrogen atom or a metal atom.)

The group represented by the formula (2) contains 2 to 10 mol% (mol%) of the aromatic dicarboxylic acid bonded to the aromatic nucleus, and further contains 40 mol% of the dicarboxylic acid.
It is composed of a polycarboxylic acid component containing the above aromatic dicarboxylic acid as an essential component and a polyol component, and has an acid value of 0.5 to 10 KOHmg / g (hereinafter, the unit is omitted and only the numbers are described. In some cases, the polyester resin

In the presence of a basic substance, at 100 ° C.
At the above temperature, it is made into fine particles by being dissolved or dispersed in water, and more particularly,
The present invention has been completed by finding that a polyester resin aqueous dispersion capable of forming a film having excellent water resistance can be obtained at a high concentration without using a solvent at all. It was

That is, the present invention is basically a method for producing an aqueous polyester resin dispersion comprising a polycarboxylic acid component containing 40 mol% or more of an aromatic dicarboxylic acid as an essential component and a polyol component. 2 to 10 mol% of the specific aromatic dicarboxylic acid in which the group represented by the above general formula [I] is bonded to the aromatic nucleus.
Including,

Further, the aromatic dicarboxylic acid in a form containing such a specific aromatic dicarboxylic acid is composed of a polycarboxylic acid component and a polyol component which are contained in an amount of 40 mol% or more in the wholly aromatic dicarboxylic acid component. And, moreover,
A polyester resin having an acid value of 0.5 to 10 (hereinafter, also referred to as water dispersible polyester resin) is dissolved in water at a temperature of 100 ° C. or higher in the presence of a basic substance, or An object of the present invention is to provide a novel method for producing an aqueous polyester dispersion, which comprises dispersion.

Here, the aromatic nucleus contains 2 to 10 mol% of the aromatic dicarboxylic acid having the group represented by the above-mentioned general formula [I] bonded thereto, and further contains the aromatic dicarboxylic acid. 40 mol of wholly aromatic dicarboxylic acid
In order to prepare a polyester resin composed of a polycarboxylic acid component containing 10% or more of a polycarboxylic acid component and a polyol component and having an acid value in the range of 0.5 to 10, any conventionally known raw material is used. Can also be used.

The polyester resin aqueous dispersion obtained according to the production method of the present invention is particularly excellent in storage stability, and in addition, the formed film has good water resistance, in particular. The water-dispersible polyester resin contains a specific aromatic dicarboxylic acid in a range of 2 to 10 mol% in a form in which a group represented by the above-mentioned general formula [I] is bonded to an aromatic nucleus. Is desirable.

When the amount of the aromatic dicarboxylic acid having the general formula [I] group bonded to the aromatic nucleus is less than 2 mol%, it is impossible to disperse the water, or the water dispersion particles become coarse. However, there is a possibility that a stable aqueous dispersion cannot be obtained. On the other hand, when the amount exceeds 10 mol% and becomes too large, the polyester resin is inevitably water-solubilized, resulting in a liquid with a very high viscosity. Could be
In addition, the obtained film, in particular, tends to have low water resistance, which is not preferable in any case.

In order to further improve the water resistance of the film to be formed, especially the water resistance, the water-dispersible polyester resin is represented by the above-mentioned general formula [I].
The total aromatic dicarboxylic acid, including the aromatic dicarboxylic acid in which the group represented by
As described above, it is desirable that the polyester resin is composed of a specific polycarboxylic acid component that is contained and a polyol component. 40mo aromatic dicarboxylic acid
If it is less than 1%, it is inevitable that the water resistance is particularly low.

The number average molecular weight of the polyester resin and water-dispersible polyester resin used in carrying out the method of the present invention is preferably in the range of 5,000 to 30,000.

The above-mentioned molecular weight is measured by gel permeation chromatography (GPC) using dimethylformamide containing lithium bromide (LiBr) at a concentration of 10 mmol / liter as a mobile phase. It means the number average molecular weight in the form of a circle.

When the molecular weight of the water-dispersible polyester resin is less than 5,000, the water resistance of the resulting coating, especially the water resistance, tends to be low, while the molecular weight of the water-dispersible polyester resin is 30, If it exceeds 000 and is too large, the water dispersion particles may inevitably become coarse, and a stable water dispersion may not be obtained. Therefore, either case is not preferable.

In addition, the glass transition point of the water-dispersible polyester resin used in carrying out the present invention is preferably 30 ° C. or higher.

Here, the above-mentioned glass transition point means the endothermic peak observed first when the temperature is raised from −50 ° C. to 10 ° C. per minute in differential scanning calorimetry (DSC). It is defined as a position and is referred to by this.

When the glass transition point is lower than 30 ° C., a sticky polyester is likely to be formed at room temperature, and it is difficult to obtain a pulverized product of the synthesized polyester. Even if it is possible to temporarily cool and pulverize it, there is a possibility that it will be re-fused during storage or during transportation.

The desired water dispersion obtained by using the water-dispersible polyester resin having a glass transition point of less than 30 ° C. is inevitably a film formed by such water dispersion.
There is a risk of stickiness and blocking,
For example, although it can be used for very limited applications such as pressure-sensitive adhesives, it is extremely difficult to be used for a wide range of applications.

What is particularly desirable as the water-dispersible polyester resin is, for example, one prepared as follows, that is, prepared by a conventional method using various raw materials shown below. You can do it.

That is, if the group represented by the above-mentioned general formula [I] is only a representative aromatic dicarboxylic acid bonded to an aromatic nucleus, it will be 4
-Sulfoisophthalic acid, 5-sulfoisophthalic acid, sulfoterephthalic acid or 4-sulfonaphthalene-2,7-
Dicarboxylic acids, their metal salts, and the like, and various dicarboxylic acid derivatives capable of condensing these can also be used.

On the other hand, if only representative examples of the above metal salts are given, Li, Na, K, Mg,
Examples thereof include salts such as Ca, Cu, and Fe. Of these, particularly preferred is 5-sodium sulfoisophthalic acid (5-sodium sulfoisophthalic acid) or dimethyl 5-sodium sulfoisophthalate (dimethyl 5-sodium sulfoisophthalate).

If the groups represented by the general formula [I] are bonded to the aromatic nucleus, and only the representative aromatic dicarboxylic acids other than the specific aromatic dicarboxylic acids are specifically exemplified, These include terephthalic acid, isophthalic acid, ortho or ortho (o) -phthalic acid, 2,6-naphthalenedicarboxylic acid, and the like, and various dicarboxylic acid derivatives which can be condensed therewith can also be used.

As described above, various aromatic dicarboxylic acids are used in an amount of 40 mol% or more, that is, used as the main component, and the remaining components are dicarboxylic acids.
As a polycarboxylic acid component of less than mol%, only typical ones are exemplified, and oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2, Various aliphatic dicarboxylic acids such as 2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid or itaconic acid;

1,3-cyclopentanedicarboxylic acid,
1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydro-o-phthalic acid, hexahydro-
o-phthalic acid, tetrachloro-o-phthalic acid, het acid or "hymic acid" [Hitachi Chemical Co., Ltd. product; this "hymic acid" is a registered trademark of the same company. ], Various alicyclic dicarboxylic acids and the like, and various condensable derivatives thereof can also be used.

If the total amount of polycarboxylic acid components is 10 mol% or less, various hydroxybenzoic acids such as p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid or salicylic acid are used. Acids; or various tri- or higher functional polycarboxylic acids such as trimellitic acid or pyromellitic acid can be used, and various condensable derivatives thereof can also be used.

On the other hand, if only typical examples of the above-mentioned polyol component are exemplified, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, Including neopentyl glycol,

1,6-hexane glycol, 2,7-dimethyl-4,7-octanediol, 2-ethyl-1,
3-hexanediol, 2-ethyl-2-butyl-1,
3-propanediol, 2,2,4-trimethyl-1,
Such as 6-hexanediol, 3-methyl-1,5-pentanediol, polyethylene glycol, polypropylene glycol or polytetramethylene glycol,
Various aliphatic diols;

Various alicyclic diols such as 1,3-cyclohexanedimethanol or 1,4-cyclohexanedimethanol; or various such as 1,4-dihydroxyethoxybenzene, ethylene oxide or propylene oxide adduct of bisphenol A The aromatic nuclei containing diol and the like can be used as one kind or a mixture of two or more kinds.

The aliphatic glycol having 4 or less carbon atoms is
It is more desirable to use the polyester resin so that it is contained in an amount of 10 mol% or more in all polyol components constituting the polyester resin.

Further, as the polyol component of the polyester resin, various tri- or higher-functional polyols such as glycerin, trimethylolpropane or pentaerythritol are used as long as the polyol component is less than 10 mol%. You can

By reacting the above-mentioned polycarboxylic acid component and the above-mentioned polyol component by a conventional method, a water-dispersible polyester resin having a group represented by the above-mentioned general formula [I] is obtained. You can do it.

That is, in an inert gas atmosphere,
In the presence or absence of a catalyst, each of the above-mentioned polycarboxylic acid component and polyol component is preferably heated to a temperature of about 180 to 300 ° C.,
It is prepared by subjecting to an esterification reaction or transesterification reaction, and then polycondensation under reduced pressure.

Here, to exemplify only typical ones of the above-mentioned catalysts, antimony oxide,
With barium oxide, zinc acetate, manganese acetate, cobalt acetate, zinc succinate, zinc borate, cadmium formate, lead monoxide, calcium silicate, dibutyltin dioxide, tetraisopropyl titanate, tetrabutyl titanate, magnesium methoxide or sodium methoxide etc. However, the polycondensation is preferably 0.1 to 10 mm.
Is performed under reduced pressure of mercury column.

The water-dispersible polyester resin used for producing the intended polyester resin water dispersion according to the method of the present invention has various characteristics depending on the combination of raw materials used and the molecular weight. Can be

In the production method of the present invention, the water-dispersible polyester resin obtained as described above is pulverized and dissolved in water in the presence of a basic substance at a temperature of 100 ° C. or higher. It is achieved by allowing or dispersing.

If the temperature at the time of water dispersion is less than 100 ° C., the obtained water dispersion particles will inevitably become coarse, and in particular, the storage stability will be poor. In some cases, it is not dispersed in water.

Here, the above-mentioned pulverized product refers to a product obtained by pulverizing a water-dispersible polyester resin once taken out as a lump or a sheet with a known and commonly used pulverizer. Preferably, the size refers to a size that passes through a 20 millimeter (mm) screen.

The above-mentioned basic substances used in carrying out the present invention include ammonia and various organic amines such as triethylamine, diethanolamine, triethanolamine, dimethylethanolamine or N-methylmorpholine. Or a variety of alkali metal or alkaline earth metal hydroxides such as NaOH, KOH or Ca (OH) _{2 and} the like.

The amount of the basic substance used is appropriately within the range in which the pH of the aqueous dispersion is around 7, and it is desirable to adjust to such a value. Generally, the acid value of the water-dispersible polyester may be measured, and an amount equivalent to the acid value of the basic substance may be used.

In carrying out the present invention, that is,
In the production of the intended polyester resin aqueous dispersion according to the method of the present invention, known and commonly used emulsifiers can be used. In this case, the emulsifier may lower the water resistance of the film formed by the water dispersion, especially, so that the amount of the emulsifier used is preferably 5% by weight or less of the water dispersible polyester resin. It is desirable to stay within such a range.

To cite only particularly representative emulsifiers which can be used, such as the potassium, sodium or ammonium salts of alkylbenzene sulphonic acid, alkylsulfuric acid or alkylallyl polyethersulfuric acid, respectively, Various anionic emulsifiers; or various nonionic emulsifiers such as polyoxyethylene alkyl ethers or polyoxyethylene alkyl allyl ethers.

Needless to say, these emulsifiers may be added at any stage before kneading water and the resin, before diluting with water, or after diluting with water. Use of this emulsifier is effective for further microparticulation and / or improvement in storage stability.

The objective polyester resin aqueous dispersion obtained by the method of the present invention is, inter alia, as a binder for adhesives, paints, inks or coating agents, or for various treating agents, and especially for fiber processing, It can be used in various fields such as paper processing, film processing or printing.

Thus, the polyester resin aqueous dispersion obtained by the method of the present invention, that is, the aqueous dispersion of the polyester resin, that is, the aqueous solution or dispersion of the polyester resin, may be used alone or if necessary, It can be used in combination with other resins and further in combination with a crosslinking agent.

By combining with a crosslinking agent, various properties such as hardness, heat resistance, water resistance or durability, etc., of the obtained film and the like are improved.

As the other resins in this case, only typical ones will be exemplified. Acrylic emulsion, synthetic rubber latex, water-based acrylic resin, water-based urethane resin, water-based phenol resin, etc. , And other aqueous polyester resins obtained by other methods, and one or more of them may be appropriately selected and used depending on the purpose of use or processing method.

Further, only typical examples of the above-mentioned cross-linking agent are shown, and aminoplast, epoxy compound or polyisocyanate compound; or polyisocyanate compound or ethyleneimine in which isocyanate group is temporarily protected. Compounds and the like, and one or more of them may be appropriately selected and used depending on the purpose of use, the processing method and the like.

If necessary, various fillers or additives such as an inorganic filler may be used in the form of addition.

[0060]

EXAMPLES Next, the present invention will be explained more specifically with reference to Synthesis Examples, Examples or Comparative Examples, but the present invention is by no means limited to these Examples. is not. In the following, all parts and% are based on weight unless otherwise specified.

Each measurement item is measured in the following manner.

(1) Composition analysis of polyester resin

It was carried out by NMR (nuclear magnetic resonance method).

(2) Molecular weight

LiBr was measured by GPC with dimethylformamide as the mobile phase containing at a concentration of 10 mmol / l.

(3) Glass transition point

It was determined by measuring DSC.

(4) Particle diameter of water dispersion

Average particle size (hydrodynamic equivalent diameter) measured by the dynamic light scattering method and analyzed by the cumulant method
It was adopted.

(5) Water resistance of film

A polyester resin aqueous dispersion having a thickness of 12
A polyethylene terephthalate film having a thickness of 5 μm (μmm) was coated so as to have a thickness of 10 μmm, and dried at 90 ° C. for 2 minutes, and then 140
Heated at ° C for 1 minute.

The coated film thus obtained was placed at 25 ° C.
After being dipped in the ion-exchanged water for 24 hours, the degree of whitening and the state of coating film adhesion were comprehensively observed and evaluated.

Evaluation 5: The coating film was completely left on the film without being whitened. 〃 4: It is extremely thin and white, but the coating film remains completely. 〃 3: Although it is thin or partly whitened, the coating film remains completely. 〃 2: The entire coating film is white, or there is partial "float" or elution. 〃 1: The entire coating film turns white and is easily peeled off when rubbed with a finger.

Alternatively, more than half of the coating film is floating or is eluted and lost.

(6) Storage stability of aqueous dispersion

The polyester resin aqueous dispersion was stored at a temperature of 40 ° C. for 1 week, and then visually evaluated to determine whether or not there was a change in appearance or sedimentation.

Evaluation 5: No change in appearance and no sedimentation. 〃 4: Appearance changes such as color change are observed, but there is no sinking. 〃 3: A small amount of sediment was generated. 〃 2: Both the change in appearance and the occurrence of sediment were observed. 〃 1: A large amount of precipitates or agglomerates were observed.

(7) Hydrolysis resistance during storage

The polyester resin aqueous dispersion was stored at a temperature of 40 ° C. for 4 weeks, and the molecular weights before and after the storage were compared.

Evaluation 5: Reduction rate less than 10% 〃 4: 〃 10% or more and less than 20% 〃 3: 〃 20% or more and less than 30% 〃 2: 〃 30% or more and less than 40% 〃 1: 〃 40% or more

Synthesis Example 1 (Preparation Example of Water-Dispersible Polyester Resin) 558 parts of ethylene glycol, 477 parts of diethylene glycol, 897 parts of terephthalic acid and 478 parts of isophthalic acid, and 0.5 part of zinc acetate, It was charged in a reaction vessel and heated from 180 ° C. to 240 ° C. over 240 minutes, and then the reaction was continued at 240 ° C. to trap 270 parts of distillate.

Subsequently, 213 parts of dimethyl 5-sodium sulfoisophthalate and 0.5 part of tetraisopropyl titanate were charged and the distillate was removed at 240 ° C. until the reaction product became transparent. , 220-280 ° C
Then, the polycondensation reaction was performed under a reduced pressure where the mercury column was 10 to 0.5 mm. Thus, the number average molecular weight is 12,4
A polyester resin (1) having a glass transition point of 00 and a glass transition point of 37 ° C. was obtained.

Synthetic Examples 2 to 5 (same as above) Further, the same as in Synthetic Example 1 except that the kinds or ratios of the raw materials used were changed as shown in Table 1.
Polyester resins (2) to (5) were obtained, respectively. The analytical composition, number average molecular weight, flow starting temperature and melt viscosity at 100 ° C. are shown together in the same table.

[0084]

[Table 1]

<< Footnotes in Table 1 >> All the numerical values of the raw material components charged mean “mol%”.

“EG” ……………… abbreviation of “ethylene glycol” “DEG” …………… abbreviation of “diethylene glycol”

Abbreviation of "CHDM" ............ "Cyclohexanedimethanol" Abbreviation of "NPG" ............ "Neopentyl glycol"

Abbreviation of "TPA" ............ "Terephthalic acid" Abbreviation of "IPA" ............ "Isophthalic acid""DMS" ............ "Dimethyl 5-sodium sulfoisophthalate" Abbreviation

Since the "number average molecular weight" in the table is a numerical value of one-hundredth, in reality, each number is multiplied by 100 (× 100). The “glass transition point” is, of course, “° C.” although its unit is omitted.

Example 1 750 parts of water and 1.0 part of 25% aqueous ammonia were stirred at a temperature of 40 ° C. in a reaction container which was equipped with a stirrer and a heating device and which could be closed. 10m while you are
250 parts of polyester resin (1) crushed to a particle size of m screen passing was added.

Then, by sealing the reaction vessel, raising the internal temperature of the vessel to 120 ° C., and continuing stirring at this temperature for 2 hours,
A desired milky white aqueous dispersion was obtained.

The average particle size of the water dispersion obtained here is 1
It was 40 nanometers (nm). The water resistance of the film of this water dispersion was good, and no change in appearance was observed even when this water dispersion was stored at a temperature of 40 ° C. for one week. Furthermore, this aqueous dispersion was mixed with 40
The number average molecular weights before and after storage at a temperature of ℃ for 4 weeks were 17,500 and 16, respectively.
It was 300, and the hydrolysis resistance was also good.

Comparative Example 1 Polyester resin (1) crushed to pass a 10 mm screen was dispersed in water in the same manner as in Example 1 except that the internal temperature of the reaction vessel was 80 ° C. and stirring was continued for 2 hours. The particle size of the obtained aqueous dispersion was 260 nm. It also contained fine flock-like insoluble matter. Although the water resistance of the film was good, the storage stability was poor.

Comparative Example 2 Polyester resin (1) crushed to pass a 10 mm screen was dispersed in water in the same manner as in Example 1 except that 25% aqueous ammonia was not used. The particle diameter of the obtained water dispersion was 320 nm. The water resistance of the film was good, but the storage stability was poor.

Comparative Example 3 In the same manner as in Example 1, an attempt was made to disperse water in the polyester resin (2) crushed to pass a 10 mm screen.
No aqueous dispersion was obtained.

Comparative Example 4 When attempting to pulverize the polyester resin (3) so as to pass through a 10 mm screen, it was stuck in the pulverization chamber and pulverization was impossible. When the polyester resin was stored in a cool box for 12 hours together with dry ice, it could be crushed. Then, the pulverized product thus obtained was immediately water-dispersed in the same manner as in Example 1. The particle diameter of the resulting aqueous dispersion was 60 nm. The water resistance of the film is
It was totally bad. When this aqueous dispersion was stored at 40 ° C. for 1 week, no change in appearance was observed thereafter. The hydrolysis resistance was not good.

Example 2 In the same manner as in Example 1, the polyester resin (4) crushed to pass a 10 mm screen was dispersed in water. The particle diameter of the obtained aqueous dispersion was 180 nm. The water resistance of the film of this water dispersion was good, and this water dispersion was
No change in appearance was observed even after storage at ℃ for 1 week. The hydrolysis resistance was also good.

Example 3 In the same manner as in Example 1, the polyester resin (5) crushed to pass a 10 mm screen was dispersed in water. The particle diameter of the obtained aqueous dispersion was 180 nm. The water resistance of the film of this water dispersion was good, and this water dispersion was
No change in appearance was observed even after storage at ℃ for 1 week. The hydrolysis resistance was also good.

Example 4 In the same manner as in Example 1 except that dimethylethanolamine was used as the basic substance, 10
mm Polyester resin crushed to pass a screen (1)
Was dispersed in water. The particle size of the obtained aqueous dispersion is 160 n
It was m. The water resistance of the film of this water dispersion was good, and when this water dispersion was stored at 40 ° C. for 1 week, no change in appearance was observed even after that. The hydrolysis resistance was also good.

Example 5 Polyester resin (1) crushed to pass a 10 mm screen was water-dispersed in the same manner as in Example 1 except that sodium hydroxide was used as the basic substance. The particle size of the obtained aqueous dispersion was 160 nm. The water resistance of the film of this water dispersion was good, and when this water dispersion was stored at 40 ° C. for 1 week, no change in appearance was observed even after that. The hydrolysis resistance was also good.

[0101]

[Table 2]

<< Footnote in Table 2 >>"Particlesize" is, of course, "nm" although its unit is omitted.

[0103]

[Table 3]

<< Footnote in Table 2 >> *: The polyester lumps could be crushed by cooling with dry ice.

**: A small amount of fine flock-like insoluble matter was produced. Evaluation was performed by removing this by filtration.

As described above, the polyester resin aqueous dispersion obtained according to the method of the present invention has particularly good storage stability and, moreover, particularly forms a film excellent in water resistance. That is. In addition, the method of the present invention is capable of producing a desired polyester resin aqueous dispersion without using any organic solvent or the like.

[0107]

INDUSTRIAL APPLICABILITY As described above, the present invention uses a completely organic solvent, which is particularly excellent in storage stability and can form a film having excellent water resistance. It is an extremely novel method that can produce a desired polyester resin water dispersion without any problems.

The method of the present invention can form a film excellent in water resistance especially because it can be dispersed in water with a small amount of hydrophilic groups as compared with the conventional manufacturing method. In addition, it is possible to provide a polyester resin water dispersion which is extremely practical and has good hydrolysis resistance and the like when the water dispersion is stored.

Claims (3)

[Claims] 1. A method for producing a polyester resin aqueous dispersion comprising a polycarboxylic acid component containing 40 mol% or more of an aromatic dicarboxylic acid as an essential component and a polyol component, wherein a compound represented by the general formula —SO ₃ M [I] (provided that M in the formula represents a hydrogen atom or a metal atom) contains 2 to 10 mol% of the aromatic dicarboxylic acid having an aromatic nucleus bound thereto, and ,
The aromatic dicarboxylic acid containing the dicarboxylic acid comprises a polycarboxylic acid component containing 40 mol% or more as an essential component and a polyol component, and has an acid value of 0.5 to 10 KO.
A method for producing an aqueous polyester resin dispersion, which comprises dissolving or dispersing Hmg / g of a polyester resin in water in the presence of a basic substance at 100 ° C. or higher. 2. The polyester resin described above is 5,000.
The manufacturing method according to claim 1, which has a molecular weight in the range of 30,000. 3. The polyester resin according to claim 1, which has a glass transition point of 30 ° C. or higher.
The manufacturing method described in.