JP2001139766A - Method for producing aqueous dispersion of thermoset resin, and water-based coating agent of thermoset resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an aqueous dispersion of a thermoset resin, good in long-term preservation stability, stable even when an amino resin such as a butylated melamine resin and a butylated benzoguanamine resin is used with a hydrophilic organic solvent, and capable of reducing the generation of a tar-like material in a drier, and further to provide a water-based coating agent containing the aqueous dispersion, and excellent in fluidity, water-resistance, hot water resistance, retort resistance, flexibility, curability, adhesion or the like. SOLUTION: This method for producing the aqueous dispersion of the thermoset resin comprises neutralizing a part or the whole of carboxyl groups in the copolymer obtained by carrying out an emulsion polymerization of (a-1) a carboxyl group- containing vinylic monomer, and (a-2) other functional group-containing vinylic monomers, with a basic compound to provide (A) an aqueous emulsion of the vinylic copolymer, and codispersing (B) an amino resin having a functional group capable of reacting with the functional group in the monomer (a-2), in the copolymer particle of the emulsion A. The water-based coating agent of the thermoset resin contains the obtained dispersion in the proportion of >=30 wt.% expressed in terms of solid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can be used in the field of coatings such as paints, plastics, paper processing, fiber processing, bonding, and ink, and can be suitably used particularly for metal coatings such as cans, aluminum sashes, and pre-coated metals. ,
In particular, it has excellent long-term storage stability, can reduce the amount of tar generated in a drying oven, and has good paint fluidity, water resistance, hot water resistance, retort resistance, flexibility, curability, adhesion, etc. The present invention relates to a method for producing a novel, useful and extremely practical thermosetting aqueous resin dispersion, and a thermosetting aqueous coating agent containing the thermosetting aqueous resin dispersion obtained by this production method. .

[0002]

2. Description of the Related Art In recent years, there has been a great demand for non-polluting type coating agents since global conservation and improvement of working environment have become social issues. Therefore, aqueous resins which are resins for non-polluting type coating agents are required. Demand is also growing rapidly.

Conventional organic solvent-containing aqueous coating agents containing a water-soluble resin as a main component include cans, aluminum sashes,
It has been used as a metal coating such as pre-coated metal.However, from the viewpoints of air pollution due to the volatilization of combustion gas, resource saving, and the use of expensive organic solvents, the shift to aqueous coating agents that use as little organic solvent as possible is desired. Yes,
Various methods have been proposed.

For example, an amino resin dispersion characterized in that a vinyl monomer having a carboxyl group is copolymerized with another vinyl monomer in an amino resin solution, partially neutralized with a basic substance, and then dispersed in water, is disclosed in Japanese Unexamined Patent Publication No. Hei. 5-1326
No. 48 discloses this.

[0005] However, as in the amino resin dispersion described in the above publication, when the resin is dispersed in water by the neutralizing power of acid and base, and the non-volatile content of the aqueous resin dispersion becomes 35% or more, It is known that the viscosity of an aqueous resin dispersion significantly decreases over time.

[0006] Even when an aqueous resin dispersion whose viscosity decreases over time is mixed with a coating material, the viscosity of the coating material also decreases over time, which results in a change in the coating amount during coating or a decrease in the mist amount. Needless to say, it may cause poor paintability such as an increase.

[0007] In addition, this method for producing an aqueous resin dispersion requires a solvent removing step of distilling off the solvent after dispersing in water. The solvent removal step of distilling off the solvent after water dispersion does not necessarily raise the temperature of the water dispersion due to the influence of the latent heat of water, and often takes a long time. Conversely, considering the efficiency of solvent removal, a low-boiling solvent must be used as a polymerization solvent for the acrylic resin. The use of a low-boiling solvent during the production of these aqueous resin dispersions is not only unfavorable from the viewpoint of improving the working environment, but also causes the low-boiling solvent to remain in the aqueous resin dispersion, causing ignition and combustion of the aqueous resin dispersion. However, there is a disadvantage that the storage conditions and the use conditions of the aqueous resin dispersion are greatly restricted due to an increase in the danger and the like.

In addition, a water-soluble resin, a water-soluble resin, is added to an aqueous resin dispersion (vinyl copolymer latex) obtained by emulsion polymerization.
A water-based paint containing a thermosetting resin is disclosed in
No. 63034.

[0009] However, in the examples of this publication, a methylated melamine resin is used as the thermosetting resin.
It is known that low-molecular-weight substances present in the methylated melamine resin volatilize and accumulate in a drying furnace to become a tan component, thereby fouling a coated product.

In order to correct the disadvantage that the amino resin such as the methylated melamine resin is volatilized in the drying furnace, for example, a method using a high molecular weight amino resin such as a butylated melamine resin or a butylated benzoguanamine resin is used. However, since these amino resins are hydrophobic, when used as a thermosetting resin for an aqueous coating agent, the addition of a hydrophilic organic solvent is essential.

However, when the molecular weight of the vinyl copolymer latex is high, it is known that the addition of the hydrophilic organic solvent destroys the dispersion state and significantly increases the viscosity of the latex. Heretofore, it has not been possible to mix a sufficient amount of butylated melamine resin or butylated benzoguanamine resin with the vinyl copolymer latex in order to exhibit various properties of the coating agent.

Further, in order to correct the hydrophobicity of amino resins such as the above-mentioned butylated melamine resins and butylated benzoguanamine resins, the butylated melamine resin,
There is a method in which a butylated benzoguanamine resin or the like is made aqueous and combined with such a vinyl copolymer latex. Examples of the method for converting the butylated melamine resin and the butylated benzoguanamine resin into an aqueous solution include, for example, oxycarboxylic acids as disclosed in US Pat. Nos. 3,464,946 and 3,444,144. And the like.

[0013] However, even with such means, water-based coatings which can satisfy various properties such as long-term storage stability, water resistance, processability, hardness and retort resistance and which are extremely practical can be obtained. No coatings could be obtained.

[0014]

Accordingly, an object of the present invention is to provide an amino resin such as a butylated melamine resin or a butylated benzoguanamine resin, which has particularly good long-term storage stability. Even when used together with a hydrophilic organic solvent as a curable resin, the dispersion state is stable without being destroyed, thereby reducing the occurrence of tan in the drying furnace, and is also a simple manufacturing method. Fluidity of paint, water resistance, hot water resistance, retort resistance, flexibility, curability, a method for producing a thermosetting aqueous resin dispersion suitable for a water-based coating agent excellent in adhesion, and the like. An object of the present invention is to provide a thermosetting aqueous coating agent containing the obtained thermosetting aqueous resin dispersion.

[0015]

Means for Solving the Problems Accordingly, the present inventors have:
Based on the recognition of the current situation, the resolution of various unresolved problems in the prior art, and the earnest demands in the art, the intensive study has led to the conclusion that aqueous vinyl copolymers obtained by emulsion polymerization have been obtained. After the production of the coalesced emulsion (A), a part or all of the carboxyl groups in the vinyl copolymer are neutralized with a basic compound, whereby the dispersion state and viscosity of the particles due to the combined use of emulsifying power and neutralizing power are obtained. After stabilization, amino resin (B) was added to the vinyl copolymer particles.
The thermosetting aqueous resin dispersion obtained by co-dispersing in the form of containing is particularly excellent in long-term storage stability, and uses butylated melamine resin, butylated benzoguanamine resin and the like together with the hydrophilic organic solvent (C). In this case, the dispersion state of the aqueous vinyl copolymer emulsion is not destroyed, and a crosslinking reaction between the aqueous vinyl copolymer emulsion (A) and the amino resin (B) occurs during baking within the particles of the aqueous resin dispersion. Because it is promoted, it is possible to reduce the occurrence of tan in the drying furnace, it is also a simple manufacturing method, fluidity of paint, water resistance, hot water resistance, retort resistance,
A thermosetting aqueous resin dispersion excellent in flexibility, curability, adhesion and the like, suitable for an aqueous coating agent, and a phosphoric acid compound (D) together with an amino resin (B) in a vinyl copolymer particle. Co-dispersion further enhances the adhesion between the coating film composed of the aqueous dispersion and the metal substrate, and co-disperses the amino resin (B) and the phosphoric acid compound (D) with a hydrophilic organic solvent ( It is easy to add those dissolved in C), and the vinyl copolymer has a number average molecular weight of 1
Those having a molecular weight of 0000 to 40,000 are amino resins (B)
As the peak area of the mononuclear moiety in the amino resin measured by size exclusion chromatography is 60% or less of the total peak area of the amino resin, or the one using benzoguanamine as an essential component, As the phosphoric acid compound (D), a phosphoric acid-modified epoxy resin was found to be preferable, and the present invention was completed.

That is, the present invention provides: Vinyl monomer having carboxyl group (a-1)
And a vinyl monomer (a-2) having a crosslinkable functional group other than a carboxyl group as an essential component, and a part or all of the carboxyl groups in a vinyl copolymer obtained by an emulsion polymerization reaction, After neutralization with a basic compound to obtain an aqueous vinyl copolymer emulsion (A), the vinyl vinyl copolymer particles in the obtained aqueous vinyl copolymer emulsion (A) A method for producing a thermosetting aqueous resin dispersion, comprising co-dispersing an amino resin (B) having a crosslinkable functional group capable of reacting with the crosslinkable functional group of the monomer (a-2),

2. An amino resin (B) dissolved in a hydrophilic organic solvent (C) is added to an aqueous vinyl copolymer emulsion (A) at 40 to 80 ° C. to give vinyl copolymer particles. 2. The method for producing a thermosetting aqueous resin dispersion according to the above 1, wherein the amino resin (B) is co-dispersed therein.

3. Amino resin (B) dissolved in hydrophilic organic solvent (C) and hydrophilic organic solvent (C) in aqueous vinyl copolymer emulsion (A) at 40-80 ° C. 2. The thermosetting aqueous resin dispersion as described in 1 above, wherein the amino acid resin (B) and the phosphoric acid compound (D) are co-dispersed in the vinyl copolymer particles by adding the phosphoric acid compound (D) thus obtained. Body manufacturing method,

4. The method for producing a thermosetting aqueous resin dispersion according to the above item 3, wherein the phosphoric acid compound (D) is a phosphoric acid-modified epoxy resin,

[5] The vinyl copolymer in the aqueous vinyl copolymer emulsion (A) has a number average molecular weight of 10,000 as determined by size exclusion chromatography.
1 to 4 which is a vinyl copolymer of up to 40,000.
A method for producing a thermosetting aqueous resin dispersion according to any one of the above,

6. The amino resin (B) described above, wherein the peak area of the mononuclear portion in the amino resin measured by size exclusion chromatography is 60% or less of the total peak area of the amino resin. 5. The method for producing a thermosetting aqueous resin dispersion according to any one of 5.

7. The method for producing a thermosetting aqueous resin dispersion according to any one of the above 1 to 5, wherein the amino resin (B) is an amino resin comprising benzoguanamine as an essential component,

8. The vinyl copolymer in the aqueous vinyl copolymer emulsion (A) is a vinyl copolymer having a hydroxyl group, and the amino resin (B) is an amino resin having an alkoxy group. Coalescing is N-
Production of the thermosetting aqueous resin dispersion according to any one of the above 1 to 7, wherein the vinyl copolymer having an alkoxyalkyl group and the amino resin (B) is an amino resin having an imino group. Method,

9. Further, a carboxyl group and a crosslinkable functional group other than the carboxyl group that can react with the crosslinkable functional group of the vinyl monomer (a-2) and / or the crosslinkable functional group of the amino resin (B) Any one of the above (1) to (8), which contains a resin aqueous solution (E) which is dissolved in an aqueous medium by neutralizing a part or all of a carboxyl group with a basic compound. Method for producing a thermosetting aqueous resin dispersion according to, and

10. The thermosetting aqueous resin dispersion obtained by the production method according to any one of the above 1 to 9, comprising 30% by weight or more in terms of solid content,
A thermosetting aqueous coating agent.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, the aqueous vinyl copolymer emulsion (A) which is a component of the thermosetting aqueous resin dispersion of the present invention is basically a vinyl monomer having a carboxyl group (a-
1) and a vinyl monomer (a-2) having a crosslinkable functional group other than a carboxyl group as an essential raw material, and if necessary, other copolymerizable vinyl monomers (a-
3) together with an emulsion polymerization reaction. Among them, an aqueous emulsion of a vinyl copolymer having a relatively low molecular weight due to excellent dispersion stability, for example, an emulsion polymerization reaction in the presence of a chain transfer agent. An aqueous emulsion of a vinyl copolymer having a number average molecular weight of 10,000 to 40,000 in terms of polystyrene by size exclusion chromatography (gel permeation chromatography) obtained by the above method is preferable, and especially 15,000.
An aqueous emulsion of 0 to 30,000 vinyl copolymers is preferred.

The size exclusion chromatography is based on the size exclusion chromatography described in JIS K0124 High Speed Chromatography.
The solution was measured using tetrahydrofuran, and the filler was measured using polystyrene gel.

The chain transfer agent used here is used for controlling the molecular weight of the vinyl copolymer in the aqueous vinyl copolymer emulsion (A) obtained through the emulsion polymerization reaction. Specifically, although not particularly limited, n-octyl mercaptan, n-lauryl mercaptan, tert-hexadecyl mercaptan, etc. Various alkyl mercaptans such as; benzyl mercaptan, various alkyl benzyl mercaptans such as dodecyl benzyl mercaptan; thioglycolic acid, various thiocarboxylic acids such as thiomalic acid and salts thereof; n-butyl thioglyconate; Such as dodecyl-3-mercaptopropionate Thiocarboxylic acid alkyl esters; various nitrogen-containing thiols such as monoethanolamine thioglycolate; various reactive functional group-containing mercaptans represented by trimethoxysilylpropyl mercaptan; α-methyl Various dimer-type chain transfer agents such as styrene dimer; various organic amines such as triethylamine and tributylamine; various organic solvents such as carbon tetrachloride and acetaldehyde; Needless to say, it may be used or two or more kinds may be used in combination. The amount of the chain transfer agent used is appropriately determined so that the number average molecular weight of the polymer obtained in the emulsion polymerization step falls within the above range.

Aqueous vinyl copolymer emulsion (A)
Examples of the vinyl monomer having a carboxyl group (a-1) used as an essential raw material include (meth) acrylic acid, crotonic acid, isocrotonic acid, and the like. Monocarboxylic acids; dicarboxylic acids such as (anhydride) maleic acid, fumaric acid, (anhydride) itaconic acid and their anhydrides; monomethyl malate, monoethyl malate, monobutyl malate, mono-2-ethylhexyl malate, Monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, mono-2-ethylhexyl fumarate, monomethyl itaconate, monoethyl itaconate, monobutyl itaconate, mono-2
Monoalkyl esters of dicarboxylic acids such as -ethylhexyl taconate and the like, and these may be used alone or in combination.
(Meth) acrylic acid, (anhydride) maleic acid, fumaric acid,
The use of itaconic acid alone.

The proportion of the vinyl monomer (a-1) having a carboxyl group is selected from the group consisting of a water-based vinyl resin dispersion having excellent resin dispersion stability and water resistance of a coating film. 0.5 to 30 parts by weight based on 100 parts by weight of all components of various monomers used in the system copolymer emulsion (A).
Parts by weight are appropriate, and in particular, 1 to 15 parts by weight is preferable.

Further, a vinyl monomer (a-2) having a crosslinkable functional group other than a carboxyl group used as an essential raw material of the aqueous vinyl copolymer emulsion (A) component
Is not particularly limited as long as it has a functional group other than a carboxyl group capable of undergoing a cross-linking reaction with the cross-linkable functional group of the amino resin (B), and is not particularly limited. For example, a hydroxyl group, an N-alkoxyalkyl group, Examples include vinyl monomers having a silyl group, an isocyanate group, or the like.

Examples of the vinyl monomer (a-2) having a crosslinkable functional group other than a carboxyl group include hydroxymethyl (meth) acrylate, 2-hydroxyethyl, and the like. Hydroxyalkyl (meth) acrylates such as (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, and hydroxyhexyl (meth) acrylate; FA-1 to F
A-5 "," Placcel FM-1 to FM-5 "(manufactured by Daicel Chemical Industries, Ltd.) and the like, and caprolactone-modified (meth) acrylates having a hydroxyl group at the terminal;
(Meth) acrylamides such as (meth) acrylamide, diacetone (meth) acrylamide and the like; N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-hydroxybutyl (meth) acrylamide and the like N-hydroxyalkyl (meth) acrylamides; N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth)
Acrylamide, N- (n-, iso) butoxymethyl (meth) acrylamide, N-methoxyethyl (meth)
N-alkoxyalkyl (meth) acrylamides such as acrylamide, N-ethoxyethyl (meth) acrylamide, N- (n-, iso) butoxyethyl (meth) acrylamide and the like, and these can be used alone or They can be used in combination.

The proportion of the vinyl monomer (a-2) having a crosslinkable functional group other than the carboxyl group is such that a thermosetting aqueous resin dispersion excellent in the curability and flexibility of the coating film can be obtained. From 1 to 100 parts by weight of all components of various monomers in the aqueous vinyl copolymer emulsion (A)
50 parts by weight is appropriate, and among them, 5 to 30 parts by weight is preferable.

Further, as essential raw materials for the aqueous vinyl copolymer emulsion (A) component, a vinyl monomer having a carboxyl group (a-1) and a vinyl monomer having a crosslinkable functional group other than a carboxyl group are used. Other copolymerizable vinyl monomers (a-3) may be used alone or as a mixture as long as the isomer (a-2) is used.

Other copolymerizable vinyl monomers (a
As -3), only typical ones are exemplified, and methyl (meth) acrylate, ethyl (meth)
Acrylate, isopropyl (meth) acrylate, n
-Butyl (meth) acrylate, isobutyl (meth) acrylate, cyclohexyl (meth) acrylate, 2
Alkyl (meth) acrylates such as ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, and stearyl (meth) acrylate; methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, n-butoxymethyl (meth) acrylate, iso- Alkoxyalkyl (meth) acrylates such as butoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, n-butoxyethyl (meth) acrylate, and isobutoxyethyl (meth) acrylate; dimethyl malate; Diethyl malate, dibutyl malate, di-2-ethylhexyl fumarate, dimethyl fumarate, diethyl fumarate, dibutyl fumarate, di-2-ethylhexyl fumarate, dimethyl Dialkyl esters of dicarboxylic acids such as taconate, diethyl itaconate, dibutyl itaconate and di-2-ethylhexyl itaconate; vinyl esters of carboxylic acids such as vinyl acetate, vinyl propionate, vinyl pivalate and vinyl versatate; vinyl acetate, propion Various vinyl esters such as vinyl acrylate and vinyl tertiary carboxylate; various aromatic vinyl compounds such as styrene, tertiary butyl styrene (tert-butyl styrene) and α-methyl styrene; vinyl pyrrolidone Various heterocyclic vinyl compounds such as; (meth) acrylonitrile,
Vinyl chloride, vinyl pyrrolidone, vinyl ether, vinyl ketone, etc .; various vinylidene halide compounds such as vinylidene chloride and vinylidene fluoride; various α-olefins such as ethylene and propylene; However, two or more kinds may be used in combination.

In the preparation of the aqueous vinyl copolymer emulsion (A), the use of a surfactant is preferred from the viewpoint of polymerization stability because emulsion polymerization is carried out.

The surfactant which can be used is not particularly limited as long as it is generally used in emulsion polymerization. Among them, only typical ones are exemplified. If it stops, sodium alkyl benzene sulfonate, ammonium alkyl benzene sulfonate, sodium alkyl sulfate, ammonium alkyl sulfate, sodium dialkyl sulfosuccinate, alkyl phenyl polyoxyethylene sulfate sodium salt,
Various anionic surfactants such as ammonium salts; various nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene-polyoxypropylene block copolymer; Various surfactants having a radically polymerizable unsaturated bond in the molecule, such as so-called reactive surfactants, are, of course, other than these, various surfactants generally used in emulsion polymerization. Can be used without any problem.

[0038] The amount of the surfactant used is the amount generally used in emulsion polymerization, that is,
The range of 0.2 to 10 parts by weight is appropriate for 100 parts by weight of all the components of the various monomers of the aqueous vinyl copolymer emulsion (A), but in consideration of the water resistance of the coating film,
The range of 0.2 to 5 parts by weight is preferable.

The emulsion polymerization can be carried out by various known and commonly used methods. For example, the radical polymerization may be carried out based on 100 parts by weight of all the components of the various monomers of the aqueous vinyl copolymer emulsion (A). The polymerization initiator is used so as to be in the range of 0.1 to 5 parts by weight, and the aqueous medium is further used in an amount of 50 to 50 parts by weight.
It is used within the range of 1,000 parts by weight,
The polymerization reaction can be performed at a temperature of about 90 ° C.

The above radical polymerization initiator may be used in an amount of 0.1.
It can also be said that the reaction is carried out by so-called redox polymerization in which 1 to 5 parts by weight and 0.1 to 5 parts by weight of the reducing agent are used in combination. At this time, a compound that generates a so-called polyvalent metal salt ion, such as an iron ion or a copper ion, can be used in combination as a promoter.

Examples of the radical polymerization initiator that can be used in the above reaction include various persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; azobisisobutyronitrile; Various azo initiators such as hydrochloride; hydrogen peroxide, ter
There are various peroxide initiators such as t-butyl hydroperoxide, cumene hydroperoxide and the like.

Further, only typical examples of the reducing agent which can be used in combination with these radical polymerization initiators include, but are not limited to, sodium sulfoxylate formaldehyde, sodium pyrosulfite, L-ascorbic acid and the like. .

From the viewpoint of practicality, the solid content concentration in the emulsion polymerization is preferably from 10 to 70, based on the aqueous vinyl copolymer emulsion (A) used for preparing the thermosetting aqueous resin dispersion according to the present invention. It is desirable that the solid content concentration is in the range of 1% by weight, and the vinyl monomer, the radical polymerization initiator and the reducing agent of the aqueous vinyl copolymer emulsion (A) are charged at once, continuously dropped or divided. It can be said to be carried out by various known and common techniques such as addition.

That is, the emulsion polymerization may be carried out by various methods such as a non-emulsifier emulsion polymerization method, a seed emulsion polymerization method, a microemulsion polymerization method, a power feed method and a shot growth method, in addition to a general emulsion polymerization method. It is also possible to adopt and apply the method of.

An aqueous vinyl copolymer emulsion (A) can also be obtained by mixing two or more separately prepared aqueous resin dispersions obtained by emulsion polymerization.

The aqueous vinyl copolymer emulsion (A) prepared as described above is obtained because the above-mentioned vinyl monomer (a-1) having a carboxyl group is used as an essential raw material. From the viewpoint of the co-dispersibility and stability of the thermosetting aqueous resin dispersion, it is essential to neutralize the dispersion with a basic compound.

The basic compound that can be used is not particularly limited, but among those, particularly typical ones are exemplified, and examples thereof include sodium hydroxide and potassium hydroxide. Various inorganic bases; monomethylamine, dimethylamine, trimethylamine,
Various alkylamines such as monoethylamine, diethylamine, triethylamine, monopropylamine, isobutylamine and dipropylamine; monoethanolamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-
There are various amino alcohols such as propanol, N-methyldiethanolamine, N-ethyldiethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine; various organic amines such as morpholine; and ammonia. Of these, organic amines having a boiling point of 80 to 180 ° C., such as triethylamine and N, N-dimethylethanolamine, are particularly preferable. However, in order to adjust the water-forming ability of the resin, various compounds as described above may be appropriately used. They can be used in combination.

Here, if the series of products is made aqueous, so-called neutralization equivalents will be mentioned.
The range of 1.5 equivalents is usually, preferably 0.6 equivalent.
It is within the range of 1.0 to 1.0 equivalent.

The amino resin (B) which is a component of the thermosetting aqueous resin dispersion of the present invention includes a crosslinkable functional group capable of reacting with the crosslinkable functional group of the vinyl monomer (a-2). As long as it is an amino resin having, there is no particular limitation, for example, an amino resin having an alkoxy group, an alkylol group, an imino group, a carboxyl group, and the like. Since the reduction can be achieved, the amino resin is preferably such that the peak area of the mononuclear moiety in the amino resin measured by size exclusion chromatography is 60% or less of the total peak area of the amino resin. 50% amino resin is preferred.

In the above-mentioned crosslinking reaction between the vinyl copolymer in the aqueous vinyl copolymer emulsion (A) and the amino resin (B), if a preferred combination is exemplified, a vinyl copolymer having a hydroxy group is exemplified. Examples thereof include an amino resin having an union and an alkoxy group, a vinyl copolymer having an N-alkoxyalkyl group, and an amino resin having an imino group.

Examples of the amino resin (B) having a crosslinkable functional group capable of reacting with the crosslinkable functional group of the vinyl monomer (a-2) include, for example, urea, melamine, benzoguanamine, cyclohexanecarboguanamine, and sterol. Guanamine, spiroguanamine, acetoguanamine, phthalocyanamine, 2- (4,6-diamino-1,3,5-triazin-2-yl) -benzoic acid, 3-
(4,6-diamino-1,3,5-triazin-2-yl) -benzoic acid, 4- (4,6-diamino-1,3,5-triazin-2-yl) -benzoic acid and the like A so-called amino group-containing compound (b
-1) is obtained by addition condensation with the aldehyde compound (b-2) and simultaneously etherification with the monohydric alcohol (b-3).

Among the above amino group-containing compounds (b-1), those containing benzoguanamine as an essential component are particularly desirable from the viewpoints of retort resistance, reduction of the amount of tar generated in a drying furnace and glossiness.

Next, as the aldehyde compound (b-2) used in the amino resin (B),
For example, formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, glyoxal and the like can be mentioned.

The component of the aldehyde compound (b-2) is preferably used formaldehyde, paraformaldehyde and glyoxal alone or in combination thereof from the viewpoint of cost and reactivity. You.

Next, the above-mentioned monohydric alcohol (b-3) used in the amino resin (B) comprises a compound having an amino group (an amino group-containing compound) and a compound having an aldehyde group (an aldehyde compound). It is necessary to stabilize the reaction product from, and among them, methyl alcohol, ethyl alcohol,
n-propyl alcohol, iso (iso-) propyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, n-octyl alcohol, 2-ethylhexyl alcohol, lauryl alcohol; ethylene Glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether; allyl alcohol, and the like, and all of them are usually used alone or in a combination thereof.

In particular, methyl alcohol, n
-Butyl alcohol, isobutyl alcohol, isopropyl alcohol are particularly preferably used.

In order to obtain the amino resin (B) used in the present invention, various known and commonly used production methods can be employed and, for example, the amino group-containing compound (b)
-1) and aldehyde compound (b-
2) in a ratio of 1.5 to 8.0 mol, and a monohydric alcohol (b-3) in a ratio of 4.0 to 20.0 mol,
The amino group-containing compound (b-1) was further added to a solution obtained by adding an aldehyde compound (b-2) to a monohydric alcohol (b-3) in the presence of an acidic catalyst. At a temperature of 40 to 120 ° C and 20 to 300
And react the condensation reaction and the etherification reaction for
What is necessary is just to carry out simultaneously.

In particular, the peak area of the mononuclear moiety in the amino resin measured by size exclusion chromatography was
In order to obtain an amino resin having 60% or less of the total peak area of the amino resin, for example, the aldehyde compound (b) is added to 1.0 mol of the amino group-containing compound (b-1). -2) is used at a ratio such that 2.0 to 6.0 mol of monohydric alcohol (b-3) becomes 8.0 to 12.0 mol, and monohydric alcohol (b-3) is used.
To the solution obtained by adding the aldehyde compound (b-2) to the solution, the amino group-containing compound (b-1) was further added at a temperature of 70 to 120 ° C. in the presence of an acidic catalyst at 6 to 120 ° C.
The reaction may be performed for 0 to 300 minutes, and the condensation reaction and the etherification reaction may be performed simultaneously.

In producing the amino resin (B),
It is preferable to check the viscosity and molecular weight, etc., and to terminate the reaction when the desired spec value is reached.

Although the amino resin (B) prepared as described above can be used and applied as it is, usually, a large amount of the remaining unreacted lower alcohol component or the amino resin (B) is removed. For the purpose of removing various organic solvents and the like used during synthesis or during aqueous conversion, first, these so-called removal components are removed by various known and common means such as heating operation or vacuum distillation. By azeotropically removing water and then using a hydrophilic organic solvent (C) together, it is possible to obtain a stable solution of the amino resin (B), and the amino resin solution thus obtained It can also be applied using.

The reason for using the hydrophilic organic solvent (C) together is that the particles of the aqueous vinyl copolymer emulsion (A) obtained by emulsion polymerization are increased by swelling, and the amino resin (B) is contained in the particles. ) Is included not only to achieve co-dispersion, but also to improve the film-forming property and wettability of the resulting thermosetting aqueous resin dispersion coated object.

Examples of such hydrophilic organic solvents (C), which are particularly representative only, include various ketones such as methyl ethyl ketone, dimethyl ketone and diacetone alcohol; ethylene glycol, diethylene glycol, dipropylene Glycols such as glycols;

Ethylene glycol monomethyl ether,
Ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol mono (iso) propyl ether, ethylene glycol di (iso) propyl ether, ethylene glycol mono (iso) butyl ether,
Ethylene glycol mono-tert-butyl ether,
Ethylene glycol monohexyl ether, 1,3-butylene glycol-3-monomethyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol,

Diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol isobutyl ether,
Diethylene glycol dibutyl ether, diethylene glycol diisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol dihexyl ether, triethylene glycol dimethyl ether,

Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol isopropyl ether, propylene glycol monobutyl ether, propylene glycol isobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether; Propylene glycol diisopropyl ether, propylene glycol dibutyl ether, propylene glycol diisobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol isopropyl ether Such as dipropylene glycol monobutyl ether, dipropylene glycol isobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dipropyl ether, dipropylene glycol diisopropyl ether, dipropylene glycol dibutyl ether, dipropylene glycol diisobutyl ether Various ether alcohols or ethers;

Various esters or ester alcohols such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, 1-methoxy-2-propyl acetate, and propylene glycol monomethyl ether acetate;

There are various alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, furfuryl alcohol, etc., which are used alone. However, two or more kinds may be used in combination.

However, considering the improvement of the working environment or the danger of ignition or burning of the thermosetting aqueous resin dispersion, the hydrophilic organic solvent (C) having a boiling point of 130 ° C. or more among the hydrophilic organic solvents (C) described above. It is more preferable to use a solvent.

The amount of the hydrophilic organic solvent (C) used is
The particles of the aqueous vinyl copolymer emulsion (A) swell and the amino resin (B) is easily co-dispersed in the particles, and the aqueous vinyl copolymer emulsion (A) and the amino resin The crosslinking reaction with the resin (B) is promoted, and the tanning problem in the drying furnace is less likely to occur, and an aqueous vinyl copolymer emulsion having excellent dispersion stability is obtained. 100 of solids
1 to 70 parts by weight, preferably 5 parts by weight,
-50 parts by weight are particularly preferred.

In the present invention, the aqueous vinyl copolymer emulsion (A) and the amino resin (B) are used in such an amount that the amino resin (B) is easily co-dispersed, and is excellent in flexibility and water resistance. Since a cured product is obtained, the weight ratio (A / B) between the resin solid content of the aqueous vinyl copolymer emulsion (A) and the amino resin (B) is 40/60 to 95 /
5 is appropriate, and the weight ratio (A /
B) is preferably in the range of 50/50 to 80/20.

The method of co-dispersion is not particularly limited. For example, the obtained aqueous vinyl copolymer emulsion (A) is preferably stirred with good stirring in an aqueous vinyl copolymer emulsion (A).
At a temperature of 0 ° C., a method of adding the obtained amino resin (B), preferably the amino resin (B) dissolved in the hydrophilic organic solvent (C), and then gradually dropping water to cause co-dispersion; In the obtained amino resin (B), preferably in the amino resin (B) dissolved in the hydrophilic organic solvent (C), at a temperature of 40 to 80 ° C., preferably with stirring, at a temperature of 40 to 80 ° C. Copolymer emulsion (A)
Is added, and then water is gradually added dropwise to cause co-dispersion.

In the co-dispersion, a method of applying a mechanical shearing force by various known and commonly used homomixers and homogenizers may be used in combination.

Next, the phosphoric acid compound (D) is used as the thermosetting aqueous resin dispersion according to the present invention, and the phosphoric acid compound (D) is added to the vinyl copolymer particles together with the amino resin (B). Co-dispersion is preferred because the adhesion between the coating film made of the thermosetting aqueous resin dispersion and the metal substrate is further improved.

The method for co-dispersing the amino resin (B) and the phosphoric acid compound (D) is not particularly limited.
In the obtained aqueous vinyl copolymer emulsion (A), the amino resin (B) and the phosphoric acid compound (D), preferably a hydrophilic organic solvent, are stirred well and preferably at a temperature of 40 to 80 ° C. A method in which an amino resin (B) dissolved in (C) and a phosphoric acid compound (D) dissolved in a hydrophilic organic solvent (C) are added, and then water is gradually added dropwise to cause co-dispersion. In a mixture of B) and a phosphoric acid compound (D), preferably an amino resin dissolved in a hydrophilic organic solvent (C) and (B) a phosphoric acid compound (D) dissolved in a hydrophilic organic solvent (C), There is a method in which the obtained aqueous vinyl copolymer emulsion (A) is added, preferably at a temperature of 40 to 80 ° C., with good stirring, and then water is gradually added dropwise for co-dispersion.

In the co-dispersion, a method of applying a mechanical shearing force using various known and commonly used homomixers and homogenizers may be used in combination.

The phosphoric acid compound (D) is a compound (d-1) having a hydroxyl group bonded to at least one phosphorus atom in one molecule. Of these, from the viewpoints of retort resistance and workability, Particularly preferred is a phosphoric acid-modified epoxy resin (d-2) composed of an epoxy compound modified with a compound having a hydroxyl group bonded to at least one phosphorus atom in one molecule.

As the phosphoric acid compound (D), only typical ones are exemplified, and as the compound (d-1) having at least one hydroxyl group bonded to at least one phosphorus atom in one molecule, For example, metaphosphoric acid, orthophosphoric acid,
Examples thereof include acids formed by hydrolyzing tetraphosphorous oxide such as pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, and the like, phosphorous acid, diphosphorous acid, hypophosphorous acid, and the like. Furthermore, (mono, di) methyl phosphate, (mono, di) ethyl phosphate, (mono,
Di) butyl phosphate, (mono, di) octyl phosphate, (mono, di) -2-ethylhexyl phosphate, (mono, di) isodecyl phosphate, monomethyl phosphite, monoethyl phosphite, monobutyl phosphite, monooctyl phosphite Examples include ester compounds such as phyto, mono-2-ethylhexyl phosphite, monoisodecyl phosphite, and the like.

The phosphoric acid-modified epoxy resin (d-2) composed of an epoxy compound modified with a compound having a hydroxyl group bonded to at least one phosphorus atom in one molecule can be obtained by various known and common synthetic methods. Among them, particularly typical ones are exemplified, and a compound (d-1) having a hydroxyl group bonded to at least one phosphorus atom in one molecule and an epoxy compound may be used, if necessary, such as an amine compound. The reaction may be carried out in the absence of a solvent or in a hydrophilic organic solvent (C) in the presence of a suitable catalyst.

As the above-mentioned epoxy compounds, particularly typical ones are exemplified. Ethylene glycol, propylene glycol, hexanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, glycerin, diglycerin, pentane Erythritol, dipentaerythritol, sorbitol,
A glycidyl ether type epoxy compound obtained by reacting an aliphatic polyol such as spiroglycol or hydrogenated bisphenol A with epichlorohydrin;

Glycidyl ether type epoxy compounds obtained by reacting an aromatic polyhydroxy compound such as catechol, resorcinol, hydroquinone, bisphenol (A, F, S, AD), tetrahydroxyphenylmethane and epichlorohydrin; Glycidyl ether type epoxy compounds obtained by reacting polyols such as ethylene oxide or propylene oxide adducts of polyhydroxy compounds with epichlorohydrin; polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol and epichlorohydrin A glycidyl ether type epoxy compound obtained by reacting

Glycidyl esters obtained by reacting an epichlorohydrin with an aliphatic or aromatic polycarboxylic acid such as propanetricarboxylic acid, butanetetracarboxylic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid and the like. Type epoxy compound;

Butadiene, hexadiene, octadiene, dodecadiene, polybutadiene, polyisoprene,
Examples thereof include linear aliphatic epoxy compounds obtained by oxidizing linear aliphatic double bonds such as soybean oil; and polyfunctional epoxy compounds such as epoxy compounds containing a heterocyclic ring such as triazine and hydantoin. . These may be used alone or as a mixture.

The phosphoric acid compound (D) prepared as described above can be used and applied as it is, or the dispersion stability of the particles of the aqueous vinyl copolymer emulsion (A) is impaired. As long as there is no such range, the hydrophilic organic solvent (C) may be used in combination.

The amount of the phosphoric acid compound (D) to be used is such that the aqueous vinyl copolymer emulsion (A) and the amino resin (A) With respect to 100 parts by weight of the total resin solid content of B), the solid content is suitably in the range of 1 to 30 parts by weight, and particularly preferably in the range of 3 to 15 parts by weight.

The thermosetting aqueous resin dispersion according to the present invention comprises:
If necessary, a carboxyl group can be reacted with a crosslinkable functional group other than the carboxyl group, the crosslinkable functional group of the vinyl monomer (a-2) and / or the crosslinkable functional group of the amino resin (B). A resin aqueous solution (E) having a crosslinkable functional group and being dissolved in an aqueous medium by neutralizing a part or all of the carboxyl group with a basic compound can be contained. Thermosetting aqueous resin dispersion,
By including the aqueous resin solution (E), it is possible to further improve the leveling property and the film forming property of the coating film composed of the thermosetting aqueous resin dispersion.

Of the aqueous resin solutions (E), only typical ones are exemplified, and acrylic resin (e-1), polyester resin (e-2), acrylic resin-modified alkyd resin, An aqueous solution of an acrylic resin-modified product (e-3) such as an acrylic resin-modified epoxy resin, an acrylic resin-modified urethane resin, an acrylic resin-modified polyester resin, or the like can be given.

As the crosslinkable functional groups other than the carboxyl group of the resin in the aqueous resin solution (E), a hydroxyl group, an N-alkoxyalkyl-substituted amide group, an epoxy group And isocyanate groups.

The aqueous solution of the acrylic resin (e-1) may be, for example, only a typical aqueous solution, and the vinyl monomer (a-1) having a carboxyl group and the aqueous solution other than the carboxyl group may be used. A vinyl monomer (a-2) having a crosslinkable functional group as an essential component, and if necessary, a monomer comprising the other copolymerizable vinyl monomer (a-3) The mixture is subjected to radical polymerization in an organic solvent, whereby a number average molecular weight of 1,000 to
After obtaining a copolymer in the range of 50,000, and then, if necessary, removing excess organic solvent from the copolymer solution obtained under reduced pressure by distillation under reduced pressure, the above-mentioned various basic compounds such as ammonia and amine are used. Some are obtained by completely or partially neutralizing a carboxyl group with a compound and dissolving it in water or a mixture of water and various hydrophilic organic solvents (C) described above.

In preparing the aqueous solution of the acrylic resin (e-1), the amount of the vinyl monomer (a-1) having a carboxyl group is determined in consideration of the water solubility of the resin and the water resistance of the coating film. Then, the solid content is converted into an acid value of 30 to 200.
It is appropriate to be within the range of mgKOH / g.

The amount of the vinyl monomer (a-2) containing a crosslinkable functional group other than the carboxyl group is determined based on the total amount of the monomer since a coating film having excellent curability and flexibility can be obtained. It is appropriate that the amount is 1 to 50 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight.

As the other copolymerizable vinyl monomers (a-3), only typical ones are exemplified, and various acrylic acid esters as described above can be used. , Various methacrylates, various aromatic vinyl compounds; various vinyl esters, and of course, these may be used alone,
Two or more kinds may be used in combination.

As typical examples of the aqueous solution of the polyester resin (e-2), only a typical example is given. Polyhydric alcohol and polycarboxylic acid are essential components, and if necessary, monocarboxylic acid is condensed. How to react,
Fatty acids, polycarboxylic acids, polyhydric alcohols and, if necessary, monocarboxylic acids are added together and condensed (esterified). This is usually called a fatty acid method. After the exchange reaction, the polyhydric carboxylic acid, the remaining polyhydric alcohol and, if necessary, the monocarboxylic acid are condensed (esterified), usually by a method called a monoglyceride method. 1,000 ~
A reaction product in the range of 5,000 is obtained, and then the carboxyl group in the reaction product thus obtained is treated with various basic compounds described above such as ammonia or an amine.
There is a form which can be obtained by completely or partially neutralizing and, if necessary, dissolving in water or a mixture of water and various hydrophilic organic solvents (C) described above.

In performing the condensation (esterification), an inert solvent azeotropic with water, such as xylene, may be added.

The above-mentioned polycarboxylic acids may be exemplified by those having only 2 or 4 carboxyl groups in one molecule, especially typical ones. Phthalic acid, isophthalic acid, terephthalic acid, succinic acid, maleic acid, itaconic acid, fumaric acid, tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, adipic acid , Sebacic acid,
Azelaic acid, "Hymic acid anhydride" [product of Hitachi Chemical Co., Ltd .; "Hymic acid anhydride" is a registered trademark of the same company. ], Trimellitic acid, methylcyclohexenetricarboxylic acid, pyromellitic acid, anhydrides thereof, and the like.

On the other hand, if only typical examples of the above-mentioned monocarboxylic acids are exemplified, benzoic acid, p-tert-butylbenzoic acid and the like may be used, and unsaturated fatty acids and the like may be used. It is possible, and if we only exemplify only those that are particularly representative,
Various fatty acids such as linseed oil, soybean oil, safflower oil, china paulownia oil, asami oil, enamel oil, and tall oil; iodine value (g iodine / 100 g, unit below) such as dehydrated castor oil fatty acid and high diene fatty acid ) Can be used, and various fatty acids such as rice bran oil, castor oil, rapeseed oil, cottonseed oil and the like can also be used. It can be used in combination with an unsaturated fatty acid.

In addition, if only typical examples of the above-mentioned polyhydric alcohols are given as examples, those having 2 to 6 hydroxyl groups in one molecule are exemplified.
If only typical ones are exemplified, ethylene glycol, propylene glycol, neopentyl glycol, butanediol, pentanediol, 1,4-cyclohexanedimethanol, 2,4,4-trimethyl- 1,3-pentanediol, butylethylpropanediol, glycerin,
There are trimethylolethane, trimethylolpropane, pentaerythritol, trisisocyanurate and the like.

The amount of the carboxyl group in the polyester resin (e-2) is 30 to 200 mg in terms of the solid content acid value in consideration of the water solubility of the resin and the water resistance of the coating film.
It is appropriate to be within the range of KOH / g.

As described above, as the crosslinkable functional group in the polyester resin (e-2), a hydroxyl group, an epoxy group and the like can be mentioned as long as only typical ones are exemplified. As the polyester resin (e-2) using a polyhydric alcohol as a raw material, it is appropriate to select a hydroxyl group.

In preparing the aqueous solution of the polyester resin (e-2), the amount of hydroxyl groups is determined by considering the ease of progress of the esterification reaction, the curability of the coating film, and the performance of the coating film. It is preferably in the range of 20 to 300 mgKOH / g, and particularly preferably in the range of 30 to 250.

In order to prepare an aqueous solution of the modified acrylic resin (e-3), various known and common production methods can be used.

If only typical production methods for acrylic resin-modified alkyd resins are exemplified, (1)
A method in which a vinyl monomer as described above is subjected to so-called radical polymerization in the presence of a so-called alkyd resin in the form of using tetrahydrophthalic anhydride, (2)
Modified resins as addition reaction products obtained by subjecting the carboxyl groups in the synthesized alkyd resin to an addition reaction with various glycidyl group / vinyl group-containing monomers such as glycidyl methacrylate, etc. In the presence of the above, a method of radically polymerizing vinyl monomers as described above can be applied.

If only a typical production method is exemplified as an acrylic resin-modified epoxy resin, the vinyl monomer as described above is subjected to radical polymerization in the presence of an epoxy resin to form an acrylic resin. A method of grafting the copolymer to the epoxy resin skeleton or the like can be applied.

The carboxyl group of the acrylic resin-modified product thus obtained is completely or partially neutralized with the above-mentioned various basic compounds such as ammonia or amine, and if necessary, is added to water or water. It is in such a form that it can be obtained by dissolving it in a mixture with the above-mentioned various hydrophilic organic solvents (C).

In preparing the aqueous solution of the modified acrylic resin (e-3), the amount of the carboxyl group is suitably in the range of 30 to 200 mgKOH / g in terms of the acid value of the solid content. In addition, when a vinyl monomer (a-2) having a crosslinkable functional group other than a carboxyl group is used when introducing a crosslinkable functional group, the amount of the vinyl monomer used is the total amount of monomers in the acrylic resin portion. For 100 parts by weight, 1 to 50 parts by weight is suitable, and 5 to 30 parts by weight is particularly suitable. However, when using a vinyl-based monomer (a-2) having a hydroxyl group when introducing a crosslinkable functional group, the amount of the hydroxyl group is in the range of 20 to 300 mgKOH / g in terms of its solid content hydroxyl value. Is preferred,
Particularly preferred is a range of 30 to 250 mgKOH / g.

The amount of the aqueous resin solution (E) used is such that a water-based vinyl copolymer emulsion (A) and an amino resin (B) can be used since a coating film having excellent leveling properties, film forming properties, and flexibility can be obtained. When the total resin solid content of the phosphoric acid compound (D) is 100 parts by weight, the solid content is suitably in the range of 1 to 40 parts by weight, and particularly preferably in the range of 3 to 15 parts by weight. .

The addition of the aqueous resin solution (E) is achieved by co-dispersing the amino resin (B) together with the phosphoric acid compound (D) in the vinyl copolymer particles of the aqueous vinyl copolymer emulsion (A), if necessary. Although it is desirable to use the method, the method is not particularly limited to this method.

In the thermosetting aqueous resin dispersion according to the present invention, when pulp or salt or the like is produced as a by-product at the time of production, the pulp or salt or the like may be removed using a filter cloth, a Knoe filter or a press filter. desirable.

The thermosetting aqueous resin dispersion according to the present invention comprises:
Although it can be used as it is as a thermosetting aqueous coating agent, the content of the thermosetting aqueous resin dispersion is usually 30% by weight or more, preferably 50 to 95%, in terms of solid content.
% By weight and used as a thermosetting aqueous coating agent.

The heat-curable aqueous coating agent may be further used, if necessary, as a so-called curing aid, an acid catalyst in a form blocked with an amine, for example, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, dinonyl. It can be said that naphthalenedisulfonic acid or the like is added within the range of 0.1 to 1 part by weight based on 100 parts by weight of the resin solid content to form a paint.

In the same manner, known and common agents such as leveling agents, antifoaming agents, pigment dispersants, anti-sagging agents, anti-segregation agents, matting agents, ultraviolet absorbers, anti-aging agents and lubricants can be used. It is also possible to add various additives. Furthermore, it can be said that the curing catalysts, pigments, and various additives are kneaded with a roll mill, a sand mill, a ball mill, a paint mixer, or the like to form a paint.

The thermosetting aqueous coating agent according to the present invention can be used as a coating agent for wood, paper, fiber, plastic, ceramics, inorganic cement base and the like, and is particularly preferably a general metal material or metal product. P
It is very useful as an undercoating and topcoating coating agent such as CM (pre-coated metal) or a beverage can or a food can such as a metal can or a film laminated can, or an electrodeposition paint.

Further, the thermosetting aqueous coating agent according to the present invention can be prepared by various known and common methods such as dipping, brushing, spray coating and roll coating. It can be applied on a material, usually at a temperature of 100 to 250 ° C. for 5 seconds to 30
By performing the baking under the heating condition of one minute, a cured product excellent in various performances can be formed.

[0113]

Now, the present invention will be described in further detail with reference to Production Examples, Comparative Production Examples, Examples and Comparative Examples, but it should be understood that the present invention is by no means limited to only these exemplifications. Not something. In the following, parts and%
All are by weight unless otherwise specified (except for the ratio of the peak area of the mononuclear moiety to the total peak area of the amino resin, as determined by size exclusion chromatography).

Production Example 1 [Preparation of aqueous vinyl copolymer emulsion (A)] 135 parts of n-butyl acrylate, 117 parts of methyl methacrylate and 39 parts of 2-hydroxyethyl methacrylate
, A mixture of a vinyl monomer and a chain transfer agent consisting of 9 parts of acrylic acid and 1.5 parts of dodecylthiol, and preparing this mixture as "HYTENOL N-08" [Daiichi Kogyo A pre-emulsion was prepared by emulsifying in 75 parts of ion-exchanged water using 6 parts of an anionic surfactant manufactured by Pharmaceutical Co., Ltd.

A reaction vessel equipped with a cooling pipe, a thermometer and a stirrer was charged with 264 parts of ion-exchanged water, and the inside of the reaction vessel was heated to 80 ° C. while stirring while introducing nitrogen gas. The above-mentioned pre-emulsion and a solution prepared by dissolving 1.5 parts of sodium persulfate in 30 parts of ion-exchanged water were separately dropped into the reaction vessel over 3 hours. After completion of the dropwise addition, stirring was continued for 2 hours while maintaining the temperature inside the reaction vessel at 80 ° C. Thereafter, 7.5 parts of triethylamine and 64 parts of ion-exchanged water were added so that the neutralization ratio became 60%, and the contents were taken out.

Thus, the nonvolatile content (the weight ratio of the nonvolatile content after volatilizing at 108 ° C. for 1.5 hours, the same applies hereinafter) is 39.7%, and the viscosity measured by a B-type viscometer (hereinafter abbreviated as “viscosity”). ) Is 100 mPa · s (millipascal
Sec), the pH was 7.8, and the desired aqueous vinyl copolymer emulsion having a number average molecular weight of 25,000 as measured by size exclusion chromatography was obtained. Hereinafter, this is abbreviated as aqueous vinyl copolymer emulsion (A-1).

Production Example 2 (same as above) 102 parts of n-butyl acrylate and 6 parts of ethyl acrylate
0 parts, 90 parts of styrene, 39 parts of N-isobutoxymethylacrylamide, 9 parts of acrylic acid, and 1.5 parts of dodecylthiol, a mixed solution of a vinyl monomer and a chain transfer agent was prepared. 75 parts of ion-exchanged water was obtained by using 4 parts of "HYTENOL N-08" and 2 parts of "AQUALON HS-10" (an anionic reactive surfactant manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Emulsify inside,
An emulsion was prepared.

Next, in the same manner as in Production Example 1 except that this pre-emulsion was used, the nonvolatile content was 39.8%,
The viscosity is 80 mPa · s, the pH is 7.7, and the number average molecular weight determined by size exclusion chromatography is 28,000.
Thus, the desired aqueous vinyl copolymer emulsion was obtained. Hereinafter, this is abbreviated as aqueous vinyl copolymer emulsion (A-2).

Production Example 3 [Preparation of Amino Resin (B)] A reaction vessel equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube was charged with 320.0 parts of methyl alcohol,
After charging 112.5 parts of paraformaldehyde and 187.0 parts of benzoguanamine, the pH was adjusted to 10.0 with a 5N aqueous sodium hydroxide solution, and the temperature was raised to 70 ° C.

After the methylolation reaction was carried out at this temperature for 2 hours, the pH was adjusted to 3.0 with a 50% aqueous sulfuric acid solution, and the etherification reaction was carried out at 70 ° C. for 4 hours. After adjusting the pH to 7.0 with an aqueous sodium hydroxide solution, a total of 350.5 parts of methyl alcohol, formaldehyde and water were distilled off under reduced pressure.

Finally, the mixture was diluted with 65 parts of ethylene glycol monobutyl ether, and the precipitated salts were filtered off.
A methoxy-type methyl ether having a nonvolatile content of 80.3%, a Gardner viscosity of Z1, a color number of 1 or less, and a peak area of a mononuclear portion measured by size exclusion chromatography of 50% of the total peak area of the amino resin; Benzoguanamine resin was obtained. Hereinafter, the amino resin (B-1)
Abbreviated.

Production Example 4 (same as above) 4 equipped with a water displacement type cooling pipe, stirrer and thermometer
In a one-necked flask, 126 parts of melamine, 262.5 parts of "KOEI FORMIT NB" [hemiformal solution manufactured by Koei Chemical Industry Co., Ltd., formaldehyde / n-butyl alcohol / water (weight ratio) = 4/5/1] Then, 312.8 parts of n-butyl alcohol was charged, the pH was adjusted to 6.0 with 50% phosphoric acid, and the mixture was heated with stirring, and the temperature was raised to 90 ° C. as the reaction temperature.

After 10 minutes had passed since the temperature reached 90 ° C., the reaction solution became homogeneous. Further, after the reaction was continued at the same temperature for 1 hour, the reaction was carried out for 6 hours while dehydrating in a boiling state. Later, 5
After adjusting the pH to 7.0 with an aqueous solution of N-sodium hydroxide, n-butyl alcohol, formaldehyde and water were distilled off under reduced pressure until the nonvolatile content became 70%.

Finally, the mixture was diluted with 33 parts of ethylene glycol monobutyl ether, and the precipitated salts were filtered off.
Imino-type butyl etherification having a non-volatile content of 64.4%, a Gardner viscosity of Z4, a color number of 1 or less, and a peak area of a mononuclear portion as measured by size exclusion chromatography of 33% of the total peak area of the amino resin. A melamine resin was obtained. Hereinafter, this is abbreviated as amino resin (B-2).

Production Example 5 [Preparation of Phosphoric Acid Compound (D)] In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, put Epicoat 1001 (epoxy compound manufactured by Shell Chemical Co., Ltd.) 110.8 And 101.8 parts of propylene glycol monomethyl ether acetate were charged and dissolved by heating. When the temperature reached 75 ° C., 7.6 parts of a 50% aqueous phosphoric acid solution was continuously added dropwise over 1 hour. 8 at 75 ° C
After reacting for hours, the mixture was neutralized with 6.1 parts of triethylamine, and the acid value of the solid content was 30 mgKOH / g, and the non-
1.1% of a phosphoric acid compound was obtained. Hereinafter, this is abbreviated as phosphoric acid compound (D-1).

Production Example 6 [Preparation of Resin Aqueous Solution (E-1)] 430 parts of 3-methoxy-1-butanol was placed in a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping tank, and nitrogen gas inlet tube. It was charged and heated to 120 ° C. While maintaining this temperature, 30 parts of methacrylic acid from the dropping tank,
Nn-butoxymethylacrylamide 60 parts, methyl methacrylate 110 parts, lauryl methacrylate 10
A mixture of 0 parts and 12.0 parts of azobisisobutyronitrile was continuously dropped over 4 hours.

One hour after the completion of the dropping, di-tert-
3.0 parts of butyl peroxide were added and the reaction was allowed to continue for a further 2 hours. Next, 360 parts of the solvent was distilled off from the resin solution thus obtained under reduced pressure, and then neutralized with 30 parts of N, N-dimethylethanolamine.

Subsequently, by diluting with 200 parts of ion-exchanged water, the nonvolatile content is 49.8%, the organic solvent content (including organic amines) is 17%, and the acid value of the resin solution is 27. An aqueous solution of an acrylic resin having a concentration of 1 mgKOH / g was obtained. Hereinafter, this is abbreviated as a resin aqueous solution (E-1).

Example 1 174 parts of an aqueous vinyl emulsion (A-1) having a non-volatile content of 39.5% was charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping tank, and heated to 75 ° C. Warmed.
While maintaining this temperature, 37.4 parts of the amino resin (B-1) having a nonvolatile content of 80.3% was charged and stirred for 1 hour. After completion of the stirring, the ion-exchanged water 2 was maintained at 75 ° C.
2.8 parts were continuously added dropwise over 3 hours. Then, after cooling to room temperature, the mixture was filtered with a 200 mesh filter cloth and a filter press.

Thus, the nonvolatile content was 40.0%, the organic solvent content (including organic amines) was 5%, and the viscosity was 1%.
A target thermosetting aqueous resin dispersion having a pressure of 50 mPa · s and a pH of 7.8 was obtained.

Examples 2 to 4 Various thermosetting resins were prepared in the same manner as in Example 1 except that the kind of the resin for the thermosetting aqueous resin dispersion and the amount used were changed as shown in Table 1. An aqueous resin dispersion was prepared.

Example 5 In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping tank, 174 parts of an aqueous vinyl emulsion (A-1) having a nonvolatile content of 40.2% was charged, and the temperature was raised to 75 ° C. Warmed.
While maintaining this temperature, 37.4 parts of the amino resin (B-1) having a nonvolatile content of 80.3% and the phosphoric acid compound (D-
1) 6 parts were charged and stirred for 1 hour. After stirring, 75
While maintaining the temperature at 3 ° C., 36.3 parts of ion-exchanged water was continuously dropped over 3 hours. Then, after cooling to room temperature, the mixture was filtered with a 200 mesh filter cloth and a Knoe filter.

Thus, the nonvolatile content was 40.2%, the organic solvent content (including organic amines) was 6%, and the viscosity was 1%.
An intended thermosetting aqueous resin dispersion having a pressure of 20 mPa · s and a pH of 7.4 was obtained.

Example 6 A reaction vessel equipped with a stirrer, thermometer, reflux condenser and dropping tank was charged with 163 parts of an aqueous vinyl emulsion (A-2) having a non-volatile content of 39.8%, and heated to 75 ° C. Warmed.
While maintaining this temperature, 46.6 parts of the amino resin (B-2) having a nonvolatile content of 64.4% and the phosphoric acid compound (D-
1) 6 parts were charged and stirred for 1 hour. After stirring, 75
While maintaining the temperature at 2 ° C., 28.4 parts of ion-exchanged water was continuously dropped over 3 hours. Then, after cooling to 50 ° C., 10 parts of an aqueous resin solution (E-1) was added. Then, after cooling to room temperature, the mixture was filtered with a 200 mesh filter cloth and a Knoe filter.

Thus, the nonvolatile content was 39.5%, the organic solvent content (including organic amines) was 8%, and the viscosity was 1%.
A target thermosetting aqueous resin dispersion having a pressure of 50 mPa · s and a pH of 7.6 was obtained.

Examples 7 to 9 [Preparation of Thermosetting Aqueous Resin Dispersion] Examples 7 to 9 were repeated except that the kind of the resin for the thermosetting aqueous resin dispersion and the amount used were changed as shown in Table 3. Various thermosetting aqueous resin dispersions were prepared in the same manner as in 5 or 6.

[0137]

[Table 1]

[0138]

[Table 2]

[0139]

[Table 3]

* 1) "Cymel 325" is a methoxy-type methylated melamine resin manufactured by Mitsui Cyanamid Co., Ltd. (nonvolatile content: 80%, peak area of mononuclear body measured by size exclusion chromatography is the total peak area of amino resin) 50%).

* 2) “Watersol S-346”
Is a water-soluble alkyd resin (65% non-volatile content) manufactured by Dainippon Ink and Chemicals, Inc.

Example 10 To 175 parts (40.0% of non-volatile content) of the thermosetting aqueous resin dispersion obtained in Example 1, "Cymel 325" was added.
5 parts, 10 parts of butyl cellosolve, 27.5 parts of water,
0.5 part of p-toluenesulfonic acid was mixed, the amount of the organic solvent was 7%, the nonvolatile content was 40%, and the viscosity was 120%.
A thermosetting aqueous coating agent having a mPa · s and a pH of 7.6 was prepared.

Example 11 25.0 parts of the amino resin (B-1) obtained in Production Example 3 were added to 200 parts of the thermosetting aqueous resin dispersion obtained in Example 6 (39.5% of non-volatile content). (Nonvolatile content 80.3%),
19.0 parts of water and 0.5 part of p-toluenesulfonic acid are mixed, and the amount of the organic solvent is 9%, the nonvolatile content is 40%, the viscosity is 110 mPa · s, and the pH is 7.4. A water-soluble coating agent was prepared.

Comparative Production Example 1 [Acrylic resin solution (x-
Preparation of 1)] In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas introduction pipe, n-butyl alcohol 150
Then, the temperature was raised to 100 ° C. While maintaining this temperature, 12 parts of methacrylic acid, 13 parts of 2-hydroxyethyl acrylate, 30 parts of methyl methacrylate, 25 parts of butyl acrylate, 20 parts of lauryl methacrylate and 20 parts of azobisisobutyronitrile 3 .0 part was continuously added dropwise over 4 hours.

One hour after the completion of dropping, di-tert-
1.0 part of butyl peroxide was added, and the reaction was continued for another 2 hours.
%, An acrylic resin solution having a number average molecular weight of 16,000 as measured by size exclusion chromatography was obtained. Hereinafter, this is abbreviated as acrylic resin solution (x-1).

Comparative Example 1 A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 250 parts of an acrylic resin solution (x-1) and 124 parts of an amino resin (B-1). Later, N,
12.7 parts of N-dimethylethanolamine and 300 parts of ion-exchanged water were added, and the mixture was sufficiently stirred at 60 ° C. until the system became uniform. Then, 424 parts of ion-exchanged water was gradually dropped with vigorous stirring to obtain a nonvolatile content of 18.0%.
After obtaining a dispersion, the solvent and water were distilled off by azeotropic distillation to obtain a nonvolatile matter having a viscosity of 38.6% and a viscosity of 4000 m.
A thermosetting aqueous resin dispersion having a Pa · s and a pH of 7.6 was obtained.

COMPARATIVE EXAMPLE 2 Melamine 126 was added to a four-necked flask equipped with a water displacement type cooling pipe, a stirrer, a thermometer and a nitrogen gas introducing pipe.
Part, "Koei Holmitt NB" 262.5 parts and n
-312.8 parts of butyl alcohol was charged, the pH was adjusted to 6.0 with 50% phosphoric acid, and the mixture was heated with stirring and heated to 90 ° C as the reaction temperature. Ten minutes after the temperature reached, the reaction solution became homogeneous. Further, the reaction was continued at the same temperature for 1 hour, and the reaction was carried out for 6 hours while dehydrating in a boiling state.

Next, 1200 parts of n-butyl alcohol was charged and heated to 100 ° C. While maintaining this temperature, 72 parts of methacrylic acid, 120 parts of 2-hydroxyethyl acrylate and 361 of methyl methacrylate were added from the dropping tank.
, A mixture consisting of 350 parts of butyl acrylate and 9.0 parts of azobisisobutyronitrile was continuously dropped over 4 hours. One hour after the completion of dropping, di-tert
9.0 parts of -butyl peroxide were added and the reaction was allowed to continue for a further 2 hours.

Next, 60.0 parts of N, N-dimethylethanolamine and 800 parts of ion-exchanged water were added, and 6
The mixture was sufficiently stirred at 0 ° C. until the system became homogeneous. Thereafter, 900 parts of ion-exchanged water was gradually dropped with vigorous stirring to obtain an aqueous dispersion having a nonvolatile content of 28.0%. Thereafter, n-butyl alcohol and water were distilled off by azeotropic distillation. Thus, a thermosetting aqueous resin dispersion having a nonvolatile content of 39.6%, a viscosity of 10,000 mPa · s, and a pH of 8.2 was obtained.

Comparative Production Example 2 [Preparation of Aqueous Vinyl Copolymer Emulsion (x-2)] In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, 80 parts of ion-exchanged water, alkyl allyl 0.05 part of sulfosuccinate and 0.3 part of sodium persulfate were charged, and the inside of the reaction vessel was heated to 75 ° C. with stirring while introducing nitrogen gas. Then, acrylic acid 1
Parts, 3 parts of methacrylic acid, 1 part of n-butyl acrylate,
A mixed solution consisting of 2 parts of methyl methacrylate and 3 parts of styrene was prepared and continuously dropped over 1 hour. After completion of the dropwise addition, stirring was continued while maintaining the temperature at 80 ° C. for 2 hours to obtain an aqueous vinyl copolymer emulsion (x-2) having a nonvolatile content of 11.0%.

Comparative Production Example 3 [Preparation of Aqueous Vinyl Copolymer Emulsion (x-3)] A reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer was obtained in Comparative Production Example 2. 90 parts of the aqueous vinyl copolymer emulsion (x-2) was charged and heated to 80 ° C. Next, charge 0.3 parts of sodium persulfate,
n-butyl acrylate 10 parts, methyl methacrylate 31 parts, styrene 30 parts, ethyl acrylate 20 parts,
A mixed solution composed of 4 parts of hydroxyethyl methacrylate and 5 parts of methacrylic acid and an emulsion composed of 40 parts of ion-exchanged water and 0.2 part of alkyl allyl sulfosuccinate were dropped from separate containers over 3 hours. After completion of the dropwise addition, stirring was continued while maintaining the temperature at 80 ° C. for 2 hours.
After cooling to 5 ° C., the pH was adjusted to 8 with aqueous ammonia. Thereafter, the nonvolatile content was adjusted to 45% with water, and the mixture was filtered with a 200-mesh filter cloth to obtain an aqueous vinyl copolymer emulsion (x-3).

Comparative Production Example 4 [Acrylic resin aqueous solution (x-
Preparation of 4)] A reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer is charged with 80 parts of ion-exchanged water, 0.05 parts of alkyl allyl sulfosuccinate and 0.3 parts of sodium persulfate. The temperature inside the reaction vessel was raised to 75 ° C. while stirring while supplying nitrogen gas. Then, acrylic acid 10
Parts, methacrylic acid 30 parts, n-butyl acrylate 10
, A mixed solution consisting of 20 parts of methyl methacrylate and 30 parts of styrene, and an emulsion consisting of 40 parts of ion-exchanged water, 3 parts of n-dodecylmercaptan and 0.5 part of alkylallylsulfosuccinate in separate containers. It was dropped over time. After completion of the dropwise addition, stirring was continued while maintaining the temperature at 80 ° C. for 2 hours. After cooling to 25 ° C., the obtained latex was neutralized and dissolved with ammonia water, and ion-exchanged water was added to reduce the nonvolatile content to 20%. % To obtain an acrylic resin aqueous solution (x-4).

Comparative Example 3 200 parts of the aqueous vinyl copolymer emulsion (x-3) obtained in Comparative Production Example 3 and 50 parts of the aqueous acrylic resin solution (x-4) obtained in Comparative Production Example 4 were mixed. Thus, an aqueous dispersion composition was obtained. Further, the aqueous dispersion composition 250
While stirring the part, the methoxy-type methylated melamine resin “Cymer 303” [manufactured by Mitsui Cyanamid Co., Ltd., 98% of non-volatile content, the peak area of a mononuclear body as measured by size exclusion chromatography is based on the total peak area of the amino resin. 6
5%], and then stirred for 1 hour. Then, after adding 0.3 parts of p-toluenesulfonic acid,
The nonvolatile content was adjusted to 40% with water, and the nonvolatile content was 39.6.
%, A viscosity of 100 mPa · s and a pH of 7.2 to obtain a thermosetting aqueous coating agent.

Comparative Example 4 200 parts of the aqueous vinyl copolymer emulsion (x-3) obtained in Comparative Production Example 3 and 50 parts of the acrylic resin aqueous solution (x-4) obtained in Comparative Production Example 4 were used. The mixture was mixed to obtain an aqueous dispersion composition. Further, this aqueous dispersion composition 2
While stirring 50 parts, the amino resin (B-2) obtained in Production Example 4 (butylated melamine resin, nonvolatile content 64.4)
%, The peak area of the mononuclear body determined by size exclusion chromatography was 33% of the total peak area of the amino resin.
%) 62 parts were gradually added, and the non-volatile content was further reduced to 35% with water.
However, the viscosity of the mixed system became extremely high, and a thermosetting aqueous coating agent could not be prepared.

Comparative Production Example 5 [Amino resin aqueous solution (b-
Preparation of 1)] A water-equipped cooling pipe, a stirrer, and a thermometer 4
Into a two-necked flask, were charged 126 parts of melamine, 262.5 parts of "KOEI FORMIT NB", 180 parts of lactic acid and 164.8 parts of n-butyl alcohol, and the pH was adjusted to 6.0 with 50% phosphoric acid. The mixture was heated with stirring and heated to 90 ° C. as the reaction temperature. After the temperature reached 90 ° C., 10 minutes passed, and the reaction solution became uniform. Further, after the reaction was continued at the same temperature for 1 hour, the reaction was carried out for 6 hours while dehydrating in a boiling state. Thereafter, the pH was adjusted to 7.0 with a 5N aqueous solution of sodium hydroxide, and then n-butyl alcohol, formaldehyde and water were distilled off under reduced pressure until the nonvolatile content became 70%.

Finally, 33 parts of ethylene glycol monobutyl ether, N, N-dimethylethanolamine 60
Parts and 15 parts of ion-exchanged water. The precipitated salts were filtered off, and the non-volatile content was 60.4%, the Gardner viscosity was Z9, the number of colors was 1 or less, and the peak area of the mononuclear portion determined by size exclusion chromatography was based on the total peak area of the amino resin. Thus, a water-soluble imino-type butyl etherified melamine resin having a concentration of 36% was obtained. Hereinafter, this is abbreviated as amino resin aqueous solution (b-1).

Comparative Example 5 While stirring 176 parts of the aqueous vinyl copolymer emulsion (A-2) (non-volatile content: 39.8%) obtained in Production Example 2, the amino resin obtained in Comparative Production Example 5 was stirred. Aqueous solution (b-
1) 50 parts were gradually added. Further, 0.3 part of p-toluenesulfonic acid was added, and the nonvolatile content was adjusted to 40% with water. The nonvolatile content was 40.3%, and the viscosity was 5000 mPa.
-A thermosetting aqueous coating agent having an s and pH of 7.2 was obtained.

Test Example 1 For the thermosetting aqueous resin dispersions obtained in Examples 1 to 9 and Comparative Examples 1 and 2, the thermosetting aqueous resin dispersion 1 was used.
P-toluenesulfonic acid 0.1 part per 100 parts.
3 parts are blended to prepare a thermosetting aqueous coating agent, and a long-term storage stability test, a test for measuring the amount of tarnishing, a coating film performance test (appearance, hot water resistance, retort resistance, pencil hardness, etc.) , Workability, gloss, adhesion). Table 4 shows the results of the long-term storage stability test, and Tables (1) and (2) collectively show other evaluation judgment results.

<< Guidelines for Evaluation and Judgment of Various Performances >> The gist of each test is as follows.

1. Long-term storage stability test Immediately after the production of each thermosetting aqueous coating agent,
The viscosity of the thermosetting aqueous coating agent after storage at 50 ° C. for 90 days was measured at 25 ° C. using a B-type viscometer, and the appearance was observed.

[0161] 2. Dust generation amount measurement test Each thermosetting aqueous coating agent was 100m long.
m, width 100 mm, thickness 0.23 mm on a tin plate, the amount of coating film (film thickness) after preliminary drying is 100 mg / 100.
It was applied with a bar coater having a size of ² cm2, preliminarily dried at 150 ° C. for 5 minutes, and then heated and dried at 180 ° C. for 10 minutes in an oven provided with a cooler at an exhaust port, and adhered to the cooler. The tar component was dissolved in acetone and collected.
A solvent such as acetone in the collected tan component is distilled off under reduced pressure, and the residue is used as a tan.
g / 100 cm ² ).

[0162] 3. Film performance test Each thermosetting water-based coating agent is 100m long
m, width 100 mm, thickness 0.23 mm on a tin plate, coated with a bar coater having a coating amount (film thickness) of 60 mg / 100 cm ^2, and dried by heating at 180 ° C. for 10 minutes. The coated panels thus obtained were used as test panels, respectively, as follows.

Coating Appearance The transparency and leveling property of each test panel were visually evaluated and judged according to the following criteria. No change on the coating film ◎◎ The cloudy area of the coating film and the area of the lumps of the coating film are less than 3% of the total area ・ ・ ・ ○ The cloudyness of the coating film and the area of the lumps of the coating film are less than 10% of the total area ··· △ The cloudy area of the paint film and the area of the bumps of the paint film are 10% or more of the total area.

Hot water resistance Each of the test panels was immersed separately in boiling water for 30 minutes, and the state of the coating film was visually evaluated according to the following criteria. No change on coating film ◎◎ Bleaching / blister area is less than 3% of total area ・ ・ ・ ○ Bleaching / blister area is less than 10% of total area ・ ・ ・ △ Bleaching / blister area is total area 10% or more of ×

Retort Resistance Each test panel was allowed to stand for 30 minutes in an autoclave heated to 130 ° C. by high-pressure steam, and the state of the coating film was visually evaluated according to the following criteria. No change on coating film ◎◎ Bleaching / blister area is less than 3% of total area ・ ・ ・ ○ Bleaching / blister area is less than 10% of total area ・ ・ ・ △ Bleaching / blister area is total area 10% or more of ×

Pencil Hardness In accordance with JIS K-5400, each test panel after the retort resistance test was evaluated by measuring the pencil scratch value at room temperature.

Workability In accordance with JIS K-5400, each test panel after the retort resistance test was subjected to an Erichsen test (6.0).
mm), and evaluated visually by the following criteria. No change on the coating film ◎◎ Crack / film peeling area is less than 1% of total area ・ ・ ・ ○ Crack / film peeling area is less than 5% of total area ・ ・ ・ 面積 Crack / film peeling area Is 5% or more of the whole area ・ ・ ・ ×

Gloss Gloss of each test panel after the retort resistance test was evaluated and evaluated by measuring a 60-degree specular reflectance (60 ° gloss;%) with a Murakami specular reflectometer.

Adhesion According to the JIS K-5400 grid tape method, 100 test squares of 1 mm × 1 mm were formed on each test panel after the retort resistance test, and an adhesive cellophane tape was adhered to the surface. The evaluation was determined by measuring the number of cross-cut coating films remaining on the coated surface after being attached and rapidly removed.

[0170]

[Table 4]

[0171]

[Table 5]

[0172]

[Table 6]

Test Example 2 The thermosetting aqueous coating agents obtained in Examples 10 to 11 and Comparative Examples 3 and 5 were tested in the same manner as in Example 1 for a long-term storage stability test, a test for measuring the amount of tanning, and a coating test. Film performance tests (appearance, hot water resistance, retort resistance, pencil hardness, workability, gloss, adhesion) were performed. The results of the long-term storage stability test are shown in Table 6, and the results of other evaluation judgments are shown in Table 7.

[0174]

[Table 7]

[0175]

[Table 8]

[0176]

The method for producing a thermosetting aqueous resin dispersion of the present invention has good long-term storage stability, and furthermore uses an amino resin such as a butylated melamine resin or a butylated benzoguanamine resin in a hydrophilic organic solvent. Even when used together, the dispersion state is stable without being destroyed, which can reduce the occurrence of tan in the drying oven, and also allows the fluidity, water resistance, hot water resistance, retort resistance, flexibility, and curing of the paint. A water-based coating agent having excellent properties and adhesion can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 61/20 C09D 5/02 63/00 157/10 C09D 5/02 161/20 157/10 163/00 161/20 C08J 3/03 163/00 F-term (reference) 4F070 AA29 AA32 AA37 AA45 AA46 AA72 AB01 AB12 AC87 AE08 CA02 CB01 CB02 CB12 4J002 BG00Y BG01W BG04W BG07W BG13W BH00W CC13X CF16X CC17Y CC18X CC16X CC17X FD204 FD206 GH01 GJ00 GK00 HA07 4J011 KA05 KB07 NA13 NA25 4J038 CG141 CG171 CH121 DA132 DA162 DA172 DB402 GA02 GA06 GA09 GA11 GA15 HA406 JC24 JC26 KA06 MA10 MA14 NA04 NA11 NA12 NA14 NA26 PB04 PC02 PC10 PC08 PC08 PC10

Claims (10)

[Claims] An emulsion polymerization reaction comprising a vinyl monomer having a carboxyl group (a-1) and a vinyl monomer having a crosslinkable functional group other than a carboxyl group (a-2) as essential components. After a part or all of the carboxyl groups in the obtained vinyl copolymer are neutralized with a basic compound to obtain an aqueous vinyl copolymer emulsion (A),
In the vinyl copolymer particles of the obtained aqueous vinyl copolymer emulsion (A), the vinyl monomer (a-
A method for producing a thermosetting aqueous resin dispersion, comprising co-dispersing an amino resin (B) having a crosslinkable functional group capable of reacting with the crosslinkable functional group of 2). 2. An aqueous vinyl copolymer emulsion (A) containing an amino resin (B) dissolved in a hydrophilic organic solvent (C) at 40 to 80 ° C. to obtain vinyl copolymer particles. The method for producing a thermosetting aqueous resin dispersion according to claim 1, wherein the amino resin (B) is co-dispersed therein. 3. An amino resin (B) dissolved in a hydrophilic organic solvent (C) and a hydrophilic organic solvent (C) in an aqueous vinyl copolymer emulsion (A) at 40 to 80 ° C. The thermosetting aqueous resin according to claim 1, wherein the phosphoric acid compound (D) is added to co-disperse the amino resin (B) and the phosphoric acid compound (D) in the vinyl copolymer particles. A method for producing a dispersion. 4. The method for producing a thermosetting aqueous resin dispersion according to claim 3, wherein the phosphoric acid compound (D) is a phosphoric acid-modified epoxy resin. 5. The vinyl copolymer in the aqueous vinyl copolymer emulsion (A) has a number average molecular weight of 10,000 to less than 10,000 as measured by size exclusion chromatography.
5. A vinyl copolymer of 40,000.
The method for producing a thermosetting aqueous resin dispersion according to any one of the above. 6. The amino resin (B), wherein the peak area of a mononuclear portion in the amino resin as measured by size exclusion chromatography is 60% or less of the total peak area of the amino resin. A method for producing the thermosetting aqueous resin dispersion according to any one of claims 1 to 5. 7. The method for producing a thermosetting aqueous resin dispersion according to claim 1, wherein the amino resin (B) is an amino resin containing benzoguanamine as an essential component. . 8. The vinyl copolymer in the aqueous vinyl copolymer emulsion (A) is a vinyl copolymer having a hydroxyl group, and the amino resin (B) is an amino resin having an alkoxy group, or The vinyl copolymer is N-
The thermosetting aqueous resin dispersion according to any one of claims 1 to 7, wherein the dispersion is a vinyl copolymer having an alkoxyalkyl group, and the amino resin (B) is an amino resin having an imino group. Production method. 9. A carboxyl group reacts with a crosslinkable functional group other than the carboxyl group, the crosslinkable functional group of the vinyl monomer (a-2) and / or the crosslinkable functional group of the amino resin (B). A resin aqueous solution (E) having a possible crosslinkable functional group and being dissolved in an aqueous medium by neutralizing a part or all of the carboxyl group with a basic compound;
The method for producing a thermosetting aqueous resin dispersion according to any one of claims 1 to 8, comprising: 10. A thermosetting aqueous resin dispersion obtained by the method according to any one of claims 1 to 9 which is contained in an amount of 30% by weight or more in terms of solid content. ,
Thermosetting aqueous coating agent.