JP2000191892A - Polyester water dispersion and preparation thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester water dispersion which exerts a stable dispersion state without any hydrophilic material or organic solvent, yields a coating layer having a high water resistance and shows a good adhesion to various substrates. SOLUTION: The titled dispersion contains, as essential components, a polyester resin (1) having an acid number of from 2 to 70 KOH mg/g, obtained by polymerizing (A) a polyhydric alcohol, (B) at least one polybasic acid compound chosen from the group consisting of polyhydric carboxylic acids, acid anhydrides thereof and lower alkyl esters thereof and (C) a compound having a functional group which is reactive against hydroxyl groups in an alkyl group or polyhydric alcohol and/or carboxyl groups in a polybasic acid compound, a neutralizing agent (2) which ionizes carboxyl groups in the polyester resin and an aqueous medium (3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyester-based aqueous dispersion and a method for producing the polyester-based aqueous dispersion. More specifically, coating agents for various films,
Aqueous polyester dispersion capable of forming a water-resistant film useful for in-line coating agents, water-based paint additives, water-based binders, paper coating agents, inks, paints, cosmetics, printers, printing presses, etc. And a method for producing the polyester-based aqueous dispersion.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of environmental protection, an aqueous dispersion in which a resin is dispersed or solubilized in water is used as a film coating agent, an in-line coating agent, an aqueous coating additive, an aqueous binder, and a paper coating. In fields where various processing agents such as agents, inks, paints, cosmetics, colorants for printers and printing presses are used, the importance of such agents is becoming increasingly important from the viewpoint of low environmental load and easy handling.

For example, a biaxially stretched and heat-set polyester film widely used as an industrial substrate because of its excellent physical and chemical properties has mechanical strength, heat resistance, gas barrier properties, electrical properties and resistance to heat. Excellent chemical properties compared to films made of other resins.

However, due to its crystal orientation, the adhesion of various treatment agents is poor.

Therefore, in order to improve the adhesiveness, a method has been adopted in which a primer layer is previously provided on a base film, a surface layer different from the base film is formed thinly, and then the coating layer is coated. At this time, as the coating agent, an aqueous dispersion is more advantageous than an organic solvent system in which a use environment is restricted.

As a resin used as such an aqueous dispersion, polyester is one of the materials having extremely excellent properties, and many studies have been made on the production method and application of polyester-based aqueous dispersion. .

Conventionally, emulsifiers have been used in these polyester-based aqueous dispersions in order to maintain the stability of the dispersed resin particles. However, this method requires a large amount of an emulsifier to reduce the particle size of the dispersed resin particles, and has a serious drawback of lowering the water resistance of the film after drying.

Further, as a method of dispersing or solubilizing a polyester resin in water without using an emulsifier, for example, a method of homopolymerizing or copolymerizing a glycol component or a dicarboxylic acid component having a sulfonic acid metal salt structure is known. . However, this method has a serious drawback that the hydrophilicity of the polyester resin itself becomes too high due to the use of the hydrophilic raw material, thereby lowering the water resistance of the film after drying.

Regarding these problems, Japanese Patent Publication No. 7-216
No. 209 discloses that after dispersing a water-insoluble polyester resin having a carboxylate group in the molecule of the resin using an organic good solvent and an organic poor solvent, the organic solvent used is distilled off to obtain a water-resistant polyester resin. A method for obtaining a polyester-based aqueous dispersion capable of forming a good film has been proposed. However, this method has a disadvantage that a large amount of an organic solvent is required to produce such an aqueous dispersion having a stable dispersion state, and thus a large amount of energy is required for recovery and separation of the solvent to be distilled off.

[0010]

SUMMARY OF THE INVENTION The present invention is based on such a technical background, and provides a coating layer having excellent water resistance, exhibits good adhesion to various base materials, and exhibits water dispersion. It is an object of the present invention to provide a polyester-based aqueous dispersion having good storage stability of a body and a method for producing the polyester-based aqueous dispersion.

[0011]

In view of the above-mentioned drawbacks in the prior art, the present inventors have conducted intensive trials to determine whether the polyester resin itself can be dispersed without using any organic solvent. Was completed.

That is, [I] the present invention relates to (A) a polyhydric alcohol and (B) at least one polybasic acid compound selected from the group consisting of a polycarboxylic acid, an acid anhydride thereof and a lower alkyl ester thereof. (C) an acid value obtained by polymerizing an alkyl group and a compound having one functional group having reactivity with a hydroxyl group of the polyhydric alcohol and / or a carboxyl group of the polybasic acid compound has an acid value of 2 to 70 KOH mg /
g of a polyester resin (1) and a neutralizing agent (2) capable of ionizing a carboxyl group of the polyester resin.
And a water-based medium (3) as an essential component. [II] The present invention relates to a compound (C) comprising an alkyl group and one epoxy compound. The present invention provides a polyester-based aqueous dispersion according to the above [I], which is a compound having a group. [III] The present invention provides (A) a polyhydric alcohol, (B) a polyhydric carboxylic acid, and an acid anhydride thereof. At least one polybasic acid compound selected from the group consisting of a compound and a lower alkyl ester thereof, and (C) an alkyl group and a hydroxyl group of the polyhydric alcohol and / or a carboxyl group of the polybasic acid compound. The polyester resin (1) having an acid value of 2 to 70 KOHmg / g obtained by polymerizing a compound having two functional groups is melted while maintaining the molten state of the melt. It is intended to provide a method for producing a polyester-based aqueous dispersion, wherein the aqueous dispersion is dispersed in an aqueous medium (3) containing a neutralizing agent (2) capable of ionizing a carboxyl group. The invention provides the production method according to the above [III], wherein the melt of the polyester resin (1) is mechanically finely dispersed in the aqueous medium (3) while maintaining the molten state.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The polyhydric alcohol as the component (A) in the present invention refers to a compound having two or more hydroxyl groups in the molecule, for example, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol,
Dipropylene glycol, polypropylene glycol,
1,4-butanediol, 1,3-propanediol,
Neopentyl glycol, 1,6-hexanediol,
1,4-cyclohexanedimethanol, 1,6-cyclohexanedimethanol, p-xylylene glycol, bisphenol A, hydrogenated bisphenol A, bisphenol A alkylene oxide adduct, glycerin, trimethylolethane, trimethylolpropane, trishydroxyethyl Examples include isocyanurate, pentaerythritol, dimethylolpropionic acid, and dimethylolbutanoic acid, and one or more of these are used.

The polycarboxylic acid as the component (B) in the present invention refers to a compound having two or more carboxyl groups in the molecule, such as adipic acid, sebacic acid, itaconic acid, fumaric acid, maleic acid, and the like. Maleic anhydride, 1,4-
Cyclohexanedicarboxylic acid, dimer acid, orthophthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, succinic anhydride, alkyl succinic acid having 8 to 20 carbon atoms, alkyl succinic anhydride, alkenyl succinic acid, alkenyl succinic anhydride , Trimellitic acid, trimellitic anhydride, trimetic acid, cyanuric acid, pyromellitic acid, pyromellitic anhydride, rosin acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid,
Examples thereof include phenylindanedicarboxylic acid and phenylquinoxalinedicarboxylic acid, and one or more of these are used. Also, instead of these polycarboxylic acids,
Alternatively, the acid anhydride or the lower alkyl ester thereof can be used in combination. As polybasic acid compounds,
When rosin acid is used, any one of maleic anhydride, maleic acid and fumaric acid is reacted and used as a tribasic acid. In this case, the rosin acid content is 5 to 5 in the acid component.
It is preferable to use 30% by weight.

If necessary, a small amount of an alkali metal sulfonic acid compound can be used. Examples of the sulfonic acid alkali metal salt-based compound include the above (A)
For the component and the component (B), 5-Na sulfoisophthalic acid, 5-ammonium sulfoisophthalic acid, 4-Na sulfoisophthalic acid, 4-methylammonium sulfoisophthalic acid, 2-Na sulfoterephthalic acid, 5-K sulfoisophthalic acid Acid, 4-K sulfoisophthalic acid, 2-K sulfoterephthalic acid, Na sulfosuccinic acid, Na sulfonate
Salt-containing bisphenol A, sodium sulfonate bisphenol A alkylene oxide adduct containing sodium salt, sulfonic acid K
Examples include base-containing hydroquinone alkylene oxide adducts.

The compound having one functional group which reacts with the alkyl group as the component (C) of the present invention and the hydroxyl group of the polyhydric alcohol and / or the carboxyl group of the polybasic acid compound includes, for example, an alkyl group and Examples include compounds having a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, an isocyanate group, or an amino group, and among these, a compound having one alkyl group and one epoxy group is preferable. The alkyl group of the compound (C) is preferably an alkyl group having 4 to 23 carbon atoms in order to adjust the balance between hydrophilicity and hydrophobicity, and the alkyl group may have a branched structure. Further, the alkyl group may have a substituent.

The compound (C) having one alkyl group and one epoxy group includes, for example, alkylphenyl glycidyl ether, alkyl glycidyl ether, alkyl glycidyl ester, glycidyl ether of phenol alkylene oxide adduct, α-olefin oxide, monoepoxy Fatty acid alkyl esters are exemplified.

Examples of the alkylphenyl glycidyl ether include phenyl glycidyl ether, cresyl glycidyl ether, nonylphenol glycidyl ether, butylphenol glycidyl ether and the like. Examples of the alkyl glycidyl ether include butyl glycidyl ether and 2-ethylhexyl glycidyl ether. Examples of the alkyl glycidyl ester include butyl glycidyl ether,
2-ethylhexyl glycidyl ether and the like. As alkyl glycidyl esters,

[0020]

Embedded image

(Where R is 4 to 20, preferably 5 carbon atoms)
-15).

The glycidyl ether of an alkylphenol or alkylene oxide adduct is, for example, a glycidyl ether of an adduct of an alkylene oxide such as ethylene oxide or propylene oxide to a lower alkylphenol such as butylphenol, and a glycidyl ether of ethylene glycol monophenyl ether or polyethylene. Glycidyl ether of glycol monophenyl ether, glycidyl ether of propylene glycol monophenyl ether, glycidyl ether of polypropylene glycol monophenyl ether, glycidyl ether of propylene glycol mono (pt-butyl) phenyl ether, and ethylene glycol monononyl phenyl ether Glycidyl ether and the like. Examples of the α-olefin oxide include alpha olefin oxide-168 [product of Adeka Argas Chemical Co., Ltd., oxirane oxygen content: 5.9%], and alpha olefin oxide-124 [Adeka Gas Gas Co., Ltd. product, oxirane oxygen content] 7.7%] and the like. The monoepoxy fatty acid ester is a compound in which an unsaturated group of an alcohol ester of an unsaturated fatty acid is epoxidized, and examples thereof include epoxidized butyl oleate and epoxidized octyl oleate.

The content of the compound (C) is not particularly limited, but is preferably 0.1 to 50% by weight, more preferably 1 to 40% by weight in the polyester resin. When the amount is less than 0.1% by weight, the dispersion stability of the obtained polyester-based water dispersion is reduced. When the amount exceeds 50% by weight, the hydrophobicity of the obtained polyester-based water dispersion is increased and the dispersion is increased. The stability will be reduced.

When a compound having one alkyl group and one epoxy group is used as the compound (C), various compounds may be used to adjust the properties of the polyester aqueous dispersion coating layer formed on the base film. A polyepoxy compound having 2 to 4 epoxy groups can be used in combination as long as the adhesiveness to the material is not impaired. Examples of this polyepoxy compound include, for example, bisphenol A type epoxy resin, novolak type epoxy resin, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether,
Examples thereof include hydroquinone diglycidyl ether and semi-dry or dry fatty acid ester epoxy compounds, and one or more of these are used.

The polyester resin used in the present invention comprises:
The above compounds (A), (B) and (C) are obtained by copolycondensation. When a polyhydric alcohol, a polycarboxylic acid derivative or a polyepoxy compound having a valency of 3 or more is used, the compounds having a valency of 3 or more are all It is preferably used in an amount of 40 mol% or less in the constituent monomers. If it is used in an amount exceeding 40 mol%, it becomes difficult to disperse the resin in an aqueous medium because a three-dimensional crosslinking reaction proceeds in the resin.

The polyester resin used in the present invention comprises:
The compound is obtained by copolycondensation of the above compounds, and a monohydric alcohol or a monovalent carboxylic acid derivative can be used in combination to control the number of terminal functional groups.

The method of the copolycondensation of the polyester resin used in the present invention is not particularly limited, and it can be arbitrarily produced by a known method. For example, a method of reacting the polyhydric alcohol of the component (A) with the polybasic acid compound of the component (B) or the monoepoxy compound of the component (C) in the presence of an esterification catalyst, or the presence of a (b) transesterification catalyst A method of transesterifying a monoepoxy compound as the component (C), a polyhydric alcohol as the component (A) and a polybasic acid lower alkyl ester compound as the component (B), and other compounds (A), (B) and (C) ), A method of performing a dehydration reaction under normal pressure, a method of performing a dehydration reaction under reduced pressure and a vacuum, a method of performing a polycondensation reaction in a solution, a method of performing a polycondensation reaction in a solid phase, and the like. Therefore, (A), (B),
(C) Simultaneously each component, (A) and (B) with (C), (A)
And (B) to (C) or (A) to (B) and (C).

The polyester resin used in the present invention comprises:
The acid value is preferably in the range of 2 to 70 KOH mg / g, and more preferably the acid value is 5 to 50 KOH mg / g. If the acid value is less than 2 KOHmg / g, the dispersion stability of the resulting polyester-based aqueous dispersion is reduced. On the other hand, when the acid value exceeds 70 KOH mg / g, the hydrophilicity of the polyester resin itself becomes too high, and the water resistance of the dried film is reduced.

The polyester-based aqueous dispersion of the present invention can be stably dispersed in water by ionizing a carboxyl group contained in the polyester resin of the present invention having a predetermined acid value with a neutralizing agent. It is characterized by being obtained.

The neutralizing agent used in this case includes, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, carbonates and acetates thereof, and aqueous ammonia and methylamine. Mono-, di-, tri-alkylamines and alkanolamines such as diethanolamine which may have a substituent such as dimethylamine, trimethylamine, ethylamine, diethylamine and triethylamine; cyclic such as piperazine and N-substituted piperazine Examples include amines, aniline, pyridine and the like. Among these neutralizers, it is particularly preferable to use aqueous ammonia.

These neutralizing agents are used in the range of 0.5 to 10 moles per mole of the acid value of the polyester resin.
If the amount of the neutralizing agent used is less than 0.5 times the acid value, the dispersion stability of the resulting polyester-based aqueous dispersion is reduced. On the other hand, when the amount of the neutralizing agent exceeds 10 times the molar number of the acid value, the physical properties of the film after drying due to an excessive amount of the alkali component are reduced.

The carboxyl group ionization reaction by the neutralizing agent used at this time may be previously neutralized with a predetermined amount of a neutralizing agent before adding and dispersing water to the polyester resin of the present invention. Further, a neutralizing agent may be added to the aqueous medium without previously neutralizing the carboxyl groups of the polyester resin of the present invention.

By adjusting the acid value of the polyester resin of the present invention and / or the amount of the neutralizing agent used, the adhesiveness, chargeability and hydrophilicity of the film obtained by applying the aqueous dispersion of the present invention are adjusted. can do.

The method for dispersing the polyester resin of the present invention in an aqueous medium is not particularly limited. For example, a polyester resin obtained by heating and melting the polyester resin of the present invention which has been previously neutralized with a neutralizing agent is used. The melt (a) is mixed with a high-temperature aqueous medium (b) by heating and, if necessary, further applying pressure, while maintaining the temperature of the mixture at a temperature that can maintain the polyester resin in a molten state. A method in which the polyester resin melt (a) is finely dispersed in an aqueous medium (b) by mechanical means, and then, if necessary, cooled to obtain an aqueous dispersion of polyester resin fine particles. Alternatively, a polyester resin melt (a) obtained by heating and melting the polyester resin of the present invention is mixed with a high-temperature aqueous medium (b) containing a neutralizing agent, heated, and further pressurized if necessary, The polyester resin melt (a) is finely dispersed in an aqueous medium (b) by mechanical means while maintaining the temperature of the mixture at a temperature that can maintain the molten state of the polyester resin, and then, if necessary, cooling. To obtain an aqueous dispersion of polyester resin fine particles. In this case, the temperature for maintaining the molten state of the polyester resin is not particularly limited, but is preferably a temperature equal to or higher than the softening point of the polyester resin. The aqueous medium used at this time, while maintaining the molten state of the polyester resin in a molten state, to disperse in the aqueous medium,
It is necessary to use a high-temperature aqueous medium which is heated and optionally pressurized. In order to bring the polyester resin of the present invention into a molten state, a heating heat exchanger or the like is used. Further, the aqueous medium is provided at 1 kg / cm ^{2 to} 20 kg provided during the process.
Pressure is applied by a pressure means of about / cm ² to adjust the temperature to an appropriate temperature. Particularly when the softening point of the resin is low, the temperature of the aqueous medium can be maintained without necessarily using a pressurizing means, and the resin can be maintained in a molten state. For this purpose, it is necessary to pressurize the aqueous medium so that the resin does not boil to a temperature at which the molten state of the resin can be maintained.

The apparatus for mechanically finely dispersing the resin melt in the aqueous medium used at this time is not particularly limited, but may be a high-speed apparatus such as a general fluid stirrer such as Cavitron (manufactured by Eurotech). A high-pressure homogenizer called a rotary continuous emulsifying / dispersing machine, a colloid mill, an ultrasonic emulsifying machine, a membrane emulsifying machine or a pressurized nozzle emulsifying machine, that is, a jet flow type, a bubble homogenizer, a microfluidizer (manufactured by Microfluidic Co., Ltd.) ), Nanomizer (Cosmo Light Co., Ltd.) and the like.

When the polyester resin of the present invention is dispersed in an aqueous medium, an organic good solvent in which the polyester is soluble is mixed with the polyester resin for the purpose of, for example, lowering the melt viscosity or softening point of the polyester resin of the present invention. After being added to the melt, it can be finely dispersed by the method described above. The organic good solvent used at this time is an organic solvent capable of dissolving 1 g or more of the polyester resin of the present invention in 100 g of the solvent, for example, a cyclic ether solvent such as tetrahydrofuran or dioxane, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone. Examples of the solvent include ketone solvents, glycol ether solvents such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether, and glycol ether ester solvents such as propylene glycol monomethyl ether acetate. These organic good solvents can be distilled off by azeotropic distillation, reduced pressure or the like after adding and dispersing an aqueous medium, if necessary.

The aqueous polyester dispersion of the present invention obtained by the above method has a particle size of 0.001 to 10 μm.
m is preferable, and 0.001 to 0.
Those having a range of 1 μm are preferred.

The solids concentration of the polyester-based aqueous dispersion of the present invention is not particularly limited, but may be 0.5 to 0.5.
It is preferably 60% by weight, more preferably 5 to 40% by weight. Further, the polyester-based aqueous dispersion of the present invention may contain, if necessary, other resins, thickeners, antistatic agents, antioxidants, heat stabilizers, flame retardants, foaming agents, defoamers, coloring agents, lubricants. Organic and / or inorganic particles, fillers, dispersants, surfactants,
It may contain an ultraviolet absorber or the like.

As a substrate on which the polyester-based aqueous dispersion of the present invention is applied, for example, polyethylene terephthalate (PET), polyethylene-2,6-naphthalate (P
EN) and a polyester film composed of a saturated polyester such as poly (1,4-cyclohexylene dimethylene terephthalate). Further, these polyesters may be copolymers containing a third component or more components in addition to the homopolymer. These polyester films are preferably biaxially stretched and heat-set.

As a method for applying the polyester aqueous dispersion of the present invention to a substrate, any known coating method, for example, a roll coating method, a gravure coating method, a roll brush method, a spray coating method, an air knife coating method, a curtain coating method The law can be applied.

When the base material is a biaxially stretched heat-fixed polyester film, the unstretched film obtained by melt-extruding the film raw material resin immediately or immediately after the longitudinal or transverse stretching treatment is performed. It can be applied to the surface layer, and further to the surface layer of the film before heat setting, which is stretched in two directions.

The polyester-based aqueous dispersion of the present invention can be used for various film coating agents, in-line coating agents, water-based paint additives, water-based binders, paper coating agents, inks, paints, cosmetics, printers, and printers. It can be applied to the field of agents and the like, and can form a film having excellent water resistance, which has never been seen before.

[0043]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. All parts and percentages in the examples are on a weight basis. Synthesis Example 1 Bisphenol A ethylene oxide adduct 64 was added to a reactor having a stirrer, a temperature controller, and an N ₂ gas introducing pipe.
9.9 g, terephthalic acid 350.1 g, Kajura E1
0 (manufactured by Shell Chemical, alkyl glycidyl ester,

Embedded image 40.0 g of carbon number of R in R = 9) and 0.3 g of dibutyltin oxide were added and stirred at 240 ° C. under a nitrogen stream. The reaction was followed by a softening point test method (ring and ball method) based on JIS K-2207. When the softening point reached 114 ° C., the reaction was terminated, and a polyester resin (R-1) was obtained. The obtained polyester resin (R-1) was a pale yellow solid, had an acid value of 7.7 mgKOH / g, a glass transition temperature of 64 ° C. by a DSC measurement method, and a weight average molecular weight of 16,000 in terms of polystyrene by a GPC measurement method. . Synthetic Examples 2 and 3 and Comparative Synthetic Example 1 A polyester resin was polymerized by the method shown in Table 1 by a method similar to that of Synthetic Example 1.

[0044]

[Table 1]

Example 1 The polyester resin (R) of Synthesis Example 1 was placed in a 1 L autoclave reactor having a stirrer, a temperature controller, and a dropping funnel.
-1) Add 100 g, and stir with a resin temperature of 180 ° C
And then pressurized the inside of the reactor system by 4 kg / cm ² . Further, 300 g of an aqueous solution containing 0.47% ammonia in the dropping funnel was heated to 140 ° C. under pressure. next,
While stirring the molten resin, 60 g of the heated aqueous solution per minute
At a rate of. After the completion of the dropwise addition, the temperature in the reaction system was cooled to room temperature and the pressure was released to obtain a polyester-based aqueous dispersion (W-1). The average particle size (D50) was 0.5 μm and the maximum particle size (Dmax) was 1.0 μm when the particle size of the resin in the aqueous dispersion was measured with a particle size distribution analyzer Microtrac UPA150. The water dispersion does not contain any organic solvent. When the obtained aqueous dispersion (W-1) was stored at room temperature for 3 months in a closed container, a portion of the resin particles settled at the lower portion of the container. However, the resin particles were easily shaken by shaking the container. Was redispersed.

Next, the obtained aqueous dispersion (W-1) was applied to an untreated polyethylene terephthalate film having a thickness of 50 μm by a bar coater so that the dry film thickness became 5 μm, and dried at 150 ° C. for 5 minutes. I let it. When the adhesion of the obtained film was measured in accordance with JIS K-5400 (cellophane adhesive tape peeling test), good results were obtained.
In addition, when the water resistance of the film was measured in accordance with JIS K-5400, the film showed excellent water resistance without whitening or peeling. Table 2 shows the results. Example 2 A polyester-based aqueous dispersion was synthesized using Cavitron (manufactured by Eurotech), which is a high-speed rotation type continuous emulsifying and dispersing machine equipped with a molten resin supply line and an aqueous medium supply line. The polyester resin (R-2) of Synthesis Example 2 was charged into a molten resin tank, and the resin heated and melted at 180 ° C. was fed into the Cavitron at a rate of 200 g / min. The aqueous medium tank was charged with a 0.28% aqueous ammonia solution, and was fed to the cabin at a rate of 1 L / min while heating to 170 ° C. At this time, the rotation speed of the rotor of the Cavitron was 8000 rpm, and the pressure in the system was 9 kg / cm ² . The atomized polyester resin aqueous dispersion is rapidly cooled to 30 ° C. and taken out, and the polyester-based aqueous dispersion (W-2) is obtained.
I got The average particle diameter (D50) was 0.4 μm and the maximum particle diameter (Dmax) was 1.0 μm when the particle diameter of the resin in the aqueous dispersion was measured by using a particle size distribution analyzer Microtrac UPA150. The water dispersion does not contain any organic solvent. When the obtained aqueous dispersion (W-2) was stored in a closed container at room temperature for 3 months, a portion of the resin particles settled at the lower portion of the container, but the resin particles were easily shaken by shaking the container. Was redispersed.

Next, the performance of the obtained polyester-based aqueous dispersion (W-2) was evaluated in the same manner as in Example 1.
Table 2 shows the results. Example 3 The polyester resin (R-3) 100 of Synthesis Example 3 was placed in a 1 L reactor having a stirrer, a temperature controller, and a dropping funnel.
g and 300 g of tetrahydrofuran and dissolved with stirring, and then 4.0 g of a 25% aqueous ammonia solution was added. Furthermore, while the dissolved and neutralized resin was stirred at room temperature, 300 g of ion-exchanged water was dropped into the reactor system at a rate of 10 g per minute from a dropping funnel. After completion of the dropwise addition, tetrahydrofuran was distilled off from the reaction system under reduced pressure, and ion-exchanged water was further added to obtain a polyester-based aqueous dispersion (W-3) with a solid content of 20%. The average particle size (D50) was 0.02 μm and the maximum particle size (Dmax) was 0.05 μm when the particle size of the resin in the aqueous dispersion was measured with a particle size distribution analyzer Microtrac UPA150. The amount of residual tetrahydrofuran in this aqueous dispersion was measured by gas chromatography (GC-8A, Shimadzu Corporation).
It was 00 ppm. When the obtained aqueous dispersion (W-3) was stored at room temperature for 3 months in a closed container, the resin particles were stable without causing any precipitation.

Next, the performance of the obtained polyester-based aqueous dispersion (W-3) was evaluated in the same manner as in Example 1.
Table 2 shows the results. Comparative Example 1 The same operation as in Example 1 was carried out except that the polyester resin (R-4) of Comparative Synthesis Example 1 was used instead of the polyester resin (R-1) used in Example 1, and a polyester-based aqueous dispersion was performed. Synthesis of body (W-4) was attempted. However, the stability of the resin particles was poor and aggregation occurred, and an aqueous dispersion could not be obtained. Comparative Example 2 Instead of the polyester resin (R-1) used in Example 1, the polyester resin (R-4) of Comparative Synthesis Example 1 was used.
The same operation as in Example 1 except that an aqueous medium containing 0.47% of ammonia to which 0.33% of poval (KL-506 manufactured by Kuraray) was added as an aqueous medium used for finely dispersing the resin was used. Was carried out to obtain a polyester-based aqueous dispersion (W-5). Resin particle diameter in this aqueous dispersion,
The average particle size (D50) was 0.6 μm and the maximum particle size (Dmax) was 2.0 μm as measured by a particle size distribution analyzer Microtrac UPA150. When the obtained aqueous dispersion (W-5) was stored in a closed container for 3 months at room temperature, almost all of the resin particles precipitated at the lower portion of the container and solidified in a cake form. From this state, the container was shaken to re-disperse the resin particles, but no re-dispersion was performed.

Next, the obtained aqueous dispersion (W-5) was applied to an untreated polyethylene terephthalate film having a thickness of 50 μm using a bar coater so that the dry film thickness became 5 μm, and dried at 150 ° C. for 5 minutes. I let it. However, the resulting coating film was turbid and was not usable.

[0050]

[Table 2]

[0051]

[0052]

The polyester resin aqueous dispersion of the present invention comprises:
Since the alkyl chain is introduced into the resin skeleton, the dispersion state is stable even without the hydrophilic materials and organic solvents that were required conventionally, and a coating layer with excellent water resistance can be obtained. Also has good adhesiveness.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 CF031 DE056 DE226 DF006 EG026 EN026 EN066 EN106 EU046 EU136 GB00 GH00 GH01 GK04 HA07 4J038 DD041 DD091 LA04 LA05 MA08 NA04 NA27

Claims (4)

[Claims] 1. A polyhydric alcohol and (B) at least one polybasic acid compound selected from the group consisting of polycarboxylic acids, their anhydrides and lower alkyl esters, and (C) an alkyl group, Hydroxyl groups of the polyhydric alcohol and / or
Or a polyester resin (1) having an acid value of 2 to 70 KOH mg / g obtained by polymerizing a carboxyl group of the polybasic acid compound and a compound having one functional group having reactivity, and a carboxyl group of the polyester resin. A polyester-based aqueous dispersion comprising, as essential components, a neutralizing agent (2) capable of ionizing water and an aqueous medium (3). 2. The polyester-based aqueous dispersion according to claim 1, wherein the compound (C) is a compound having an alkyl group and one epoxy group. (3) at least one polybasic acid compound selected from the group consisting of (A) a polyhydric alcohol, (B) a polyhydric carboxylic acid, an acid anhydride thereof and a lower alkyl ester thereof, and (C) an alkyl group; Hydroxyl groups of the polyhydric alcohol and / or
Alternatively, a melt of a polyester resin (1) having an acid value of 2 to 70 KOH mg / g, which is obtained by polymerizing a carboxyl group of the polybasic acid compound and a compound having one reactive group having reactivity, While maintaining the molten state of the body,
A method for producing a polyester-based aqueous dispersion, comprising dispersing the polyester resin in an aqueous medium (3) containing a neutralizing agent (2) capable of ionizing a carboxyl group of the polyester resin. 4. A melt of the polyester resin (1),
The production method according to claim 3, wherein the fine dispersion is mechanically finely dispersed in the aqueous medium (3) while maintaining the molten state.