JP3000645B2 - Method for producing synthetic resin aqueous dispersion - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a water dispersion of a synthetic resin having excellent defoaming properties and excellent wettability, which is useful for paints, fiber treatment, or mounting. More specifically, since the content of the organic solvent is extremely small or not contained at all, it can sufficiently respond to resource saving, low pollution, safety and sanitation, etc., and also has various workability such as coating and spray coating. The present invention relates to a method for producing a synthetic resin aqueous dispersion having excellent performance.

(Prior Art) Various methods for producing an aqueous dispersion of a high molecular weight polyurethane resin have been proposed. For example, JP-B-43-9076 and JP-B-44-27904 disclose a compound having a basic tertiary amino group which can be neutralized with an acid or quaternized in a polyurethane material, and a salt thereof. By including a compound having a carboxylic acid group or a sulfonic acid group capable of forming in the polyurethane material, a salt is formed before or during the addition of water to the polyurethane material, whereby the polyurethane material is dissolved in water. A method for dispersing or dispersing in water is disclosed.

Also, by using an emulsifier in combination, the hydrophobic prepolymer is dispersed in water using mechanical shearing force to increase the molecular weight, or a high molecular weight polyurethane resin solution is synthesized in advance, and then the emulsifier is dissolved. A method is also known in which water is added dropwise to cause phase inversion emulsification from a water-in-oil type to an oil-in-water type.

However, in any method, it is essential to use an organic solvent in combination in order to more easily carry out addition polymerization or to easily carry out emulsification and dispersion.

As a result, a considerable amount of organic solvent remains in the resulting resin dispersion, and resource saving, which is now strongly demanded by society,
It had the drawback that it could not respond to low pollution, safety and health, etc.

In order to eliminate such drawbacks, a method of reducing the amount of the organic solvent by subjecting the obtained synthetic resin aqueous dispersion containing the organic solvent to desolvation under reduced pressure is a very effective method.

However, in this case, foaming at the time of removing the solvent is remarkable, which causes problems such as a remarkable decrease in yield and an extremely long time required.

There is a method of using an antifoaming agent to suppress this foaming.

However, when an antifoaming agent is used, even if the amount is very small, the synthetic resin aqueous dispersion obtained is particularly limited in application because it causes cissing, pinholes and the like, especially when applied to a plastic film or a metal surface. Results.

For this reason, a synthetic resin aqueous dispersion for spray or roll coating which needs to be used at a low viscosity in which a conventional antifoaming agent cannot be used is foamed when the solvent is removed under reduced pressure. Could not be reduced. Therefore, only a type containing a large amount of a solvent having a high flammability and a high boiling point in a hydrophilic container (eg, N-methylpyrrolidone, dimethylformamide, etc.) could be produced industrially.
Therefore, there has been a long-awaited demand for a synthetic resin aqueous dispersion having a low solvent content or no solvent and having good coating suitability.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for removing an organic solvent contained in an aqueous synthetic resin dispersion under reduced pressure in a short time without using an antifoaming agent. It is to be.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present inventors have made intensive studies and as a result have completed the present invention.

That is, the present invention is characterized in that, when an organic solvent in a synthetic resin aqueous dispersion is removed by distillation to produce a synthetic resin aqueous dispersion, an acetylene alcohol derivative and / or an acetylene glycol derivative (A) are added and distilled. To produce a synthetic resin aqueous dispersion.

 Hereinafter, the present invention will be described in detail.

The synthetic resin according to the present invention is not particularly limited, and examples thereof include a polymer resin, a polycondensation resin, and an addition polymerization resin. Examples of such a synthetic resin include polyolefin, acrylic, and vinyl. -Based, styrene-based, butadiene-based, etc .; alkyd-based, polyester-based, polyamide-based, polyimide-based, phenol-based, urea-based, melamine-based, guanamine-based, etc .; polyether-based, polythioether-based resins And polyaddition resins such as polysulfone, polycarbonate, polyurea, polyurethane, polyurethane polyurea, epoxy, fluorine, and silicone.

The form of the synthetic resin aqueous dispersion is not particularly limited, and is a self-emulsifying type containing a hydrophilic group or a group that can become hydrophilic in a polymer, or an emulsifier in which a hydrophobic polymer is emulsified and dispersed by an external emulsifier. Examples include a containing type, a type in which a hydrophobic polymer is co-dispersed using the above-mentioned self-emulsifying polymer as a dispersant, and a combination type thereof. In particular, a self-emulsifying type or a co-dispersing type containing no emulsifier is preferable.

There are various methods for producing the synthetic resin aqueous dispersion according to the present invention. For example, a method in which a raw material (a monomer or the like) is charged into an organic solvent, polymerized, and then dispersed in water,
A method of once synthesizing a synthetic resin, dissolving it in an organic solvent and then dispersing it in water, a method of dissolving the synthetic resin in an organic solvent, further reacting the raw materials (monomer and the like), and then dispersing the resin in water. However, the manufacturing method is not particularly limited.

Examples of the compound having a hydrophilic functional group that is essential for synthesizing the self-emulsifying synthetic resin aqueous dispersion in the present invention include a group consisting of ethylene oxide repeating units, ethylene oxide repeating units and other alkylene oxides. And a compound having a sulfonic acid salt group, a carboxylic acid salt group, a quaternary amino group, and the like.

Examples of the functional group that can be hydrophilic include a compound having a carboxylic acid group, a sulfonic acid group, and a tertiary amino group. Specific compounds will be described later.

Hereinafter, the compound having a hydrophilic functional group and the compound having a functional group that can become hydrophilic are simply referred to as “compound having a hydrophilic functional group”.

A typical production method when the aqueous synthetic resin dispersion in the method of the present invention is a polyurethane resin aqueous dispersion is as follows. That is, it has at least two active hydrogen atoms reactive with isocyanate groups in the molecule in an organic solvent, and has a molecular weight of 62 to 2
After reacting an active hydrogen-containing compound (a) with an organic polyisocyanate compound (b) to prepare a prepolymer having an isocyanate group at the end, and then dispersing the prepolymer in water simultaneously or after dispersing in water. A method of extending a chain with a polyamine compound (c) or water in water, and reacting the active hydrogen-containing compound (a) with an organic polyisocyanate compound (b) in an organic solvent to obtain a high-molecular-weight polyurethane. Is a method of dispersing
At this time, in order to disperse the prepolymer or polyurethane in water, a compound having a hydrophilic functional group is contained in the prepolymer or polyurethane, only an emulsifier is used, or both are used.

Here, the molecule has an active hydrogen atom reactive with at least two isocyanate groups, and has a molecular weight of 62 to 20,000.
The active hydrogen-containing compound (a) is a compound that is generally linear and contains a hydroxyl, carboxyl, amino, or mercapto group at the terminal. For example, ethylene glycol, propylene glycol, 1,3-propanediol,
1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, trimethylene glycol,
Triethylene glycol, tetraethylene glycol,
Dipropylene glycol, tripropylene glycol,
Bishydroxyethoxybenzene, 1,4-cyclohexane diol, 1,4-cyclohexane dimethanol, bisphenol A, hydrogenated bisphenol A, relatively low molecular weight diols such as hydroquinone, these diols and succinic acid, adipic acid, Azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid , 2,5-Naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p'-dicarboxylic acid and anhydrides or esters of these dicarboxylic acids Forming derivative; p-hydroxybenzoic acid, p- (2-hydro Polyester diols obtained by a dehydration condensation reaction from acid components such as (ethoxy) benzoic acid and ester-forming derivatives of these hydroxycarboxylic acids, and polyester diols obtained by a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone; Copolymerized polyester diol, polypropylene glycol, propylene oxide using one or more of the above-mentioned relatively low molecular weight diols such as polytetramethylene glycol as an initiator,
Polyether diols, poly (tetramethylene carbonate) diols, poly (hexamethylene carbonate) diols and the like obtained by addition polymerization of one or more monomers such as butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene by a conventional method. Compounds obtained by the reaction of the above-mentioned relatively low molecular weight diol with diphenyl carbonate, phosgene, chloroformate or the like can be mentioned.

Use of other polyacetals, polythioethers, polyamides, polyesteramides, polyolefins, silicones or polyhydroxy compounds containing urethane or urea groups and also natural diols, including those optionally modified such as castor oil, carbohydrates Can be done.

Usually, a bifunctional active hydrogen-containing compound is used, but polyhydroxy compounds such as glycerin, trimethylolethane, trimethylolpropane, sorbitol, and pentaerythritol; polycarboxylic acids such as trimellitic acid and pyromellitic acid; diethylenetriamine and triethylene. Polyamine compounds such as ethylenetetramine and the like, or polyesters, polyethers, polyamides, polyesteramides and the like obtained by copolymerizing them may be used.

As the organic polyisocyanate compound (b) used in the method of the present invention, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane Diisocyanate, 2,
4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,
4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-
Naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate Isocyanate, tetramethyl xylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate, and the like.

Other than these, for example, a diisomer or trimer of the above isocyanate or a polyisocyanate partially blocked with phenols, oximes, tertiary alcohols, phthalimides or lactams may be used. .

Examples of the compound having a hydrophilic functional group used for dispersing the above-mentioned prepolymer or polyurethane in water include a group having at least one active hydrogen atom in the molecule and having a repeating unit of ethylene oxide. A group consisting of ethylene oxide repeating units and other alkylene oxide repeating units, carboxylic acid salts, sulfonic acid salts, quaternary amino groups, carboxylic acid groups, sulfonic acid groups, and tertiary amino groups. A compound containing at least one selected functional group is exemplified.

Such hydrophilic group-containing compounds include, for example, 2-oxyethanesulfonic acid, phenolsulfonic acid, sulfobenzoic acid, sulfosuccinic acid, 5-sulfoisophthalic acid, sulfanilic acid, 1,3-phenylenediamine-4,6-disulfonic acid, Sulfonic acid-containing compounds such as 2,4-diaminotoluene-5-sulfonic acid and the like and derivatives thereof or polyester polyols obtained by copolymerizing them; 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2 Carboxylic acid-containing compounds such as 1,2-dimethylolvaleric acid, dioxymaleic acid, 2,6-dioxybenzoic acid, 3,4-diaminobenzoic acid and derivatives thereof or polyester polyols obtained by copolymerizing them; ethylene oxide At least 30% by weight or more of at least one active water in the polymer Containing molecular weight 30
0 to 20,000 polyoxyethylene glycol or polyoxyethylene-polyoxypropylene copolymer glycol, polyoxyethylene-polyoxybutylene copolymer glycol, polyoxyethylene-polyoxyalkylene copolymer glycol or monoalkyl ether thereof, etc. And a polyester polyether polyol obtained by copolymerizing these nonionic group-containing compounds, and these are used alone or in combination.

Examples of the emulsifier that can be used in the method of the present invention include polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene sorbitol tetraoleate, and polyoxyethylene / polyoxypropylene copolymer. Nonionic emulsifiers such as coalescing; fatty acid salts such as sodium oleate, alkyl sulfates, alkyl benzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, polyoxyethylene alkyl sulfates, alkane sulfonate sodium salts, alkyls Anionic emulsifiers such as sodium salt of diphenyl ether sulfonic acid are exemplified.

Examples of the polyamine compound (c) used in the present invention include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,
5-dimethylpiperazine, isophoronediamine, 4,4 '
Diamines such as dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine and 1,4-cyclohexanediamine; polyamines such as diethylenetriamine, dipropylenetriamine and triethylenetetramine; hydrazines; acids Hydrazides are used, and these are used alone or in combination.

In the production of a synthetic resin aqueous dispersion such as the polyurethane resin aqueous dispersion of the present invention, the reaction is carried out uniformly, the reaction heat is controlled, the viscosity of the reaction system is reduced, or the reaction system is dispersed in water. An organic solvent is used for the purpose of using as a dispersing aid.

Although the kind of the organic solvent is not particularly limited, for example, aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; acetates such as ethyl acetate and butyl acetate; isopropanol; Alcohols such as butanol; amides such as dimethylformamide and N-methylpyrrolidone;

As such an organic solvent, a solvent having a relatively low boiling point is preferably used because it is finally removed by distillation. Even when it is necessary to use an organic solvent having a boiling point of 100 ° C. or more, it is preferable to keep the amount of use to a minimum.

The amount of the organic solvent to be used is usually 5 to 200% (% by weight) based on the solid content of the synthetic resin. If the amount of the organic solvent is less than 5% with respect to the solid content of the synthetic resin, the viscosity of the synthetic resin solution generally becomes too high, which tends to be difficult to disperse in water, which is not preferable. When the amount of the organic solvent is more than 200% based on the solid content of the synthetic resin, even if the amount of the organic solvent is further increased, the water dispersibility is not improved, and the amount of the solvent removed is uneconomical. .

When the aqueous synthetic resin dispersion of the present invention is an aqueous polyurethane resin dispersion, the aqueous dispersion method includes, as described above, a method of prepolymerizing in an organic solvent and then dispersing in water to form a polyurethane, There is a method of dispersing in water after pre-polyurethane formation.However, as a method of dispersing in water, phase inversion emulsification may be carried out by dropping water while stirring into a prepolymer or polyurethane organic solvent solution. Alternatively, an organic solvent solution of a prepolymer or polyurethane may be dropped into water that is well stirred. These methods may be of a batch type or a continuous type.

The aqueous polyurethane resin dispersion containing the organic solvent thus obtained is then distilled under reduced pressure to remove the organic solvent. The present invention is characterized in that acetylene alcohol and acetylene glycol are added at that time. As acetylene alcohol and acetylene glycol, for example, Acetylene alcohol (R ₁ , R ₂ : a hydrogen atom or an alkyl group having 1 to 10 carbon atoms) represented by Acetylene glycol (R ₁ , R ₄ : a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; R ₂ , R ₃ : a methyl group or an ethyl group) represented by Acetylene glycol (R ₁ , R ₄ : a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; R ₂ , R ₃ : a methyl group or an ethyl group; m, n: an integer m + n = 3 to 60) No.

Among these, acetylene glycol is particularly preferred. The amount used is in the range of 0.005 to 3% (apparent weight ratio) based on the synthetic resin aqueous dispersion containing an organic solvent and dispersed in water. In this case, if the content is less than 0.005%, the defoaming effect at the time of desolvation is reduced, and there is a problem that an extremely long time is required for desolvation or the solvent cannot be removed, which is not preferable. Also, if the amount used exceeds 3%,
Even if the amount used is further increased, the defoaming effect at the time of solvent removal does not increase and it is uneconomic. In addition, since these acetylene alcohols / acetylene glycols have a boiling point higher than water and are less likely to volatilize, the film forming speed is slowed down. It is not preferable because it remains in the coating film even after drying and lowers the water resistance. The preferred amount is 0.01 to 1%.

The solubility in acetylene alcohol / acetylene glycol and water (the number of g dissolved in 100 g of water) is 0.
When one or two or more compounds selected from alcohols, glycol ethers and glycols in the range of 0.1 to 10 are used in combination, the defoaming effect is further improved.

Such compounds include, for example, n-butanol, n-
Alcohols such as hexanol, n-heptanol and n-octanol; glycols such as ethylene glycol and propylene glycol; and glycol ethers such as hexyl cellosolve.

Further, instead of the above specific alcohols, glycol ethers and glycols, polyoxyalkylene glycol derivatives such as ethylene oxide and other alkylene oxides such as random or block copolymers of propylene oxide or polypropylene glycol are added in combination. May be. Further, these three components may be mixed and used. The addition amount of these compounds is 5 parts or more, preferably 10 to 500 parts, per 100 parts of acetylene alcohol / acetylene glycol.

In addition, these acetylene alcohol / acetylene glycol and other compounds may be used as one component of the emulsifier.

Various distillation apparatuses can be used to remove the organic solvent by distillation, and examples thereof include vacuum distillation by batch and continuous distillation. Of these, a distillation apparatus that does not release distillation efficiency or an organic solvent removed by distillation to the atmosphere is preferable, and a thin film evaporator is particularly preferable.

As a particularly preferred continuous thin film evaporator used in the present invention, specifically, for example, "Chemical Equipment Handbook, No. 40
4 to 407 (1989) ", for example, a Sebucon evaporator manufactured by Hitachi, Ltd.
A horizontal control device or a vertical control device, Shinko Faudler's WFE thin film distillation device, etc.
Among these, a vertical device in which the rotating shaft is installed in the vertical direction may not have the liquid pool.

Distillation is generally carried out at an apparatus jacket temperature of about 20-130.
° C, preferably 30 to 90 ° C, the degree of vacuum is about 5 to 300 mmHg,
The reaction is preferably carried out under a condition of 10 to 200 mmHg, whereby most of the organic solvent contained in the aqueous synthetic resin dispersion is removed.

The synthetic resin aqueous dispersion obtained by the method of the present invention may be used in combination with other aqueous dispersions, for example, emulsions of vinyl acetate, ethylene vinyl acetate, acrylic, acrylic styrene, etc .;
Latexes such as butadiene, acrylonitrile / butadiene, and acryl / butadiene; polyethylene,
Polyolefin-based ionomers; polyurethane, polyester, polyamide, and epoxy-based aqueous dispersions can be blended and used in an arbitrary ratio. Further, fillers such as carbon black, clay, talc, and aluminum hydroxide; additives such as silica sol, alumina sol, plasticizer, and pigment; film-forming assistants such as alkylene glycol derivatives; epoxy resins, melamine resins, isocyanate compounds, and aziridines Compounds, crosslinking agents for polycarbodiimide compounds;
A leveling agent or the like may be blended and used.

The method in which acetylene alcohol and / or an acetylene glycol derivative is added to the aqueous synthetic resin dispersion according to the method of the present invention and distillation is carried out under reduced pressure is very low in foaming at the time of distillation, so that the distillation can be performed in a short time without bumping trouble. It can be performed. In addition, the resulting low-solvent or non-solvent aqueous dispersion of synthetic resin produces cissing and pinholes that were observed when distillation was performed using a conventional silicone-based or mineral oil-based antifoaming agent. And has extremely excellent coating properties (wetting properties) and leveling properties.

The synthetic resin aqueous dispersion according to the method of the present invention has excellent paintability on metals and plastics, and can be used in many applications that could not be applied with the conventional synthetic resin aqueous dispersion, and it can also be used in conventional methods. Defects such as a decrease in adhesion of the dried film and generation of pinholes, which have been problems with the foaming agent, can also be improved. Therefore, various plastics, metals, inorganic materials, textiles, water-based inks, vehicles for automotive water-based paints and household water-based paints
It can be used for a wide range of applications as various coating agents and adhesives for paper, leather, wood and the like.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples at all without departing from the technical idea of the present invention.

Example 1 In a four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, first, a polyester of 1,6-hexanediol / neopentyl glycol / adipic acid (OH value: 102) was added to 53 flasks.
Add 3.2 parts, dehydrate at 120-130 ° C under reduced pressure, then 50
7.7 parts neopentyl glycol and 662 parts
Of methyl ethyl ketone, and mix well with stirring.
Three parts of 4,4'-dicyclohexylmethane diisocyanate were added, heated to 80 ° C, and reacted at this temperature for 2 hours to obtain a prepolymer solution having a terminal isocyanate group.
After completion of the reaction, the mixture is cooled to 40 ° C, and dimethylolpropionic acid 5
Add 9.1 parts and continue stirring and cooling at 70 ° C. until the NCO% reaches 2.5%. Then, while stirring at high speed with a homomixer, 2790 parts of water containing 44.6 parts of triethylamine was added to prepare an aqueous dispersion of a prepolymer, and further, anhydrous piperazine 3
387 parts of an aqueous solution in which 8.7 parts are dissolved is added dropwise over about 1 minute. Acetylene glycol (Surfinol 440 air / water) was added to 1000 parts of the milky aqueous dispersion thus obtained.
Products and Chemicals (2 parts) (0.2% vs. aqueous dispersion) was added, and methyl ethyl ketone was removed at 55 ° C. under reduced pressure while stirring. Low foaming during solvent removal, approx. 40
The solvent removal of methyl ethyl ketone was completed in minutes. Water was added to adjust the concentration to obtain a polyurethane resin aqueous dispersion having a nonvolatile content of 30% and containing no methyl ethyl ketone.
The resulting polyurethane resin aqueous dispersion was applied on an untreated steel sheet by air spray so as to have a thickness of 20 microns (dry film thickness), and a very good glossy coating film without cissing or pinholes was obtained. Obtained.

Examples 2 to 5, Comparative Examples 1 to 2 The results of synthesizing a resin in the same manner as in Example 1 and changing the type and amount of the additive at the time of solvent removal (Examples 2 to 5,
Comparative Examples 1 and 2) are as shown in the table.

(Effect of the Invention) The aqueous dispersion of a synthetic resin obtained by the method of the present invention is excellent in coating workability, and is preferably applied by using, for example, spray coating, roll coating, gravure coating, or the like used at a very low viscosity. A good coating film can be obtained.

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08J 3/00-3/28 C08L 1/00-101/14

Claims (8)

(57) [Claims] An organic solvent in a synthetic resin aqueous dispersion is distilled off to produce a synthetic resin aqueous dispersion, wherein an acetylene alcohol derivative and / or an acetylene glycol derivative (A) is added for distillation. A method for producing a synthetic resin aqueous dispersion. 2. An aqueous dispersion of a synthetic resin comprising an acetylene alcohol derivative and / or an acetylene glycol derivative (A), and a solubility in water (g which is soluble in 100 g of water).
No.) Production of a synthetic resin aqueous dispersion, characterized in that one or more compounds (B) selected from alcohols, glycol ethers and glycols in the range of 0.01 to 10 are added and distilled. Method. 3. An aqueous synthetic resin dispersion, comprising adding an acetylene alcohol derivative and / or an acetylene glycol derivative (A) and a polyoxyalkylene glycol derivative (C) to the aqueous synthetic resin dispersion, followed by distillation. Manufacturing method. 4. An aqueous dispersion of a synthetic resin containing an acetylene alcohol derivative and / or an acetylene glycol derivative (A) and a solubility in water (g soluble in 100 g of water).
Number) adding and distilling one or more compounds (B) selected from alcohols, glycol ethers and glycols in the range of 0.01 to 10 and a polyoxyalkylene glycol derivative (C). A method for producing a synthetic resin aqueous dispersion characterized by the following. 5. The method for producing an aqueous dispersion of a synthetic resin according to claim 4, wherein a polyoxyethylene / polyoxypropylene glycol copolymer is used as the polyoxyalkylene glycol derivative (C). 6. The method for producing a synthetic resin aqueous dispersion according to claim 1, wherein a polyurethane resin aqueous dispersion is used as the synthetic resin aqueous dispersion. 7. The method for producing a synthetic resin aqueous dispersion according to claim 1, wherein a self-emulsifying aqueous polyurethane resin dispersion is used as the synthetic resin aqueous dispersion. 8. The synthetic resin aqueous dispersion according to any one of claims 1 to 7, wherein a thin film evaporator is used as a distillation apparatus when the organic solvent in the synthetic resin aqueous dispersion is removed by distillation. Manufacturing method.