JPS5855990B2 - Suiseinetsukoseihifukuzaisoseibutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition that has a high solids concentration and an extremely small amount of organic solvent component among the total volatile components in the coating composition.

Conventionally, most of the paints used in the paint industry and the painting industry have been organic solvent-based paints, which have good coating workability and properties of the coated products obtained.

Although these organic solvent-based paints have the excellent properties mentioned above, they contain large amounts of organic solvents, and these organic solvents are released into the atmosphere during the painting process. From the viewpoints of hygiene, being unfavorable for hygiene, causing air pollution, being likely to cause fires, and causing economic and resource loss, we recommend using coating materials that do not contain organic solvents as much as possible, especially water-based coatings. The development of coating materials is strongly desired.

The aqueous thermosetting coating compositions that have been developed so far are used in very special coating fields such as electrodeposition coating and dip coating, where it is essential to use a coating with a low solid content concentration. However, there are not many water-based thermosetting coating materials that can be used for spray coating, roll coating, etc., which are more general coating methods than these coating methods.

The reason for this is that, for example, when coating materials are applied by spray painting, the viscosity must be kept fairly low; however, in water-based coating materials that use water as a solvent, This is because the viscosity of the coating material changes significantly depending on the amount of water contained, and it is much more difficult to create an aqueous coating material with a viscosity suitable for coating than conventionally used organic solvent-based coating materials.

In addition, in order to create a water-based coating material that has an appropriate coating viscosity for spray painting, it is sufficient to add a fairly large amount of aqueous solvent to the coating material, but the water-based coating material made in this way has a low solid content concentration. Not only is it necessary to repeat the coating many times in order to form a coating film with the desired thickness, but the solvent that makes up the water-based coating material has a low volatility of water. Because it is a main component, the paint film is prone to paint defects such as sagging, scuffing, and repelling.In addition, the resulting paint film has excellent chemical resistance, solvent resistance, stain resistance, and outdoor durability. It was extremely difficult to form.

Therefore, the present inventors have developed an aqueous thermosetting coating material composition that does not have the disadvantages mentioned above, especially one that has a high solids concentration even when the aqueous coating material is diluted to the optimum coating viscosity for spray coating, and that As a result of studies to obtain an aqueous coating material that can form a coating film free of coating defects such as wrinkles, sagging, and repellency, we found that an organic polymer obtained by polymerizing a vinyl monomer of a specific composition in an organic solvent or a water-containing organic solvent. Dilute an organic solvent solution of a polymer with a ratio of 65/35 to 90/10 with water or water and an organic solvent so that the ratio of total organic solvent to water is 5/95 to 30/70. The present invention was completed by discovering that the object could be achieved by creating a covering material that was

The gist of the present invention is (A) 3-40 hydroxyalkyl ester of monoethylenically unsaturated carboxylic acid.
Weight %, (B) monoethylenically unsaturated carboxylic acid 5-1
5% by weight, (q N-alkoxymethylated monoethylenically unsaturated carboxylic acid amide 1 to 10% by weight, 0 other copolymerizable monoethylenically unsaturated compounds 35 to 91
A solution of a copolymer obtained by copolymerizing monomers in a proportion of % by weight in an organic solvent or a water-containing organic solvent such that the proportion of the copolymer to the organic solvent is 65 to 90% by weight; a base capable of neutralizing the carboxylic acid groups of 5 to 40 parts by weight of N per 100 parts by weight of the copolymer;
- An aqueous thermosetting coating material consisting of alkoxymethylated melamine and water, and the ratio of organic solvent to water in the total volatile components in this coating material is 5/95 to 30/70 (weight ratio). An aqueous coating material characterized by:

Specific examples of hydroxyalkyl esters/L(A) of monoethylenically unsaturated carboxylic acids for producing copolymers used in carrying out the present invention include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ( Examples include meth)acrylate, 3-hydroxypropyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, etc. These compounds may be used alone or in combination of two or more in a proportion of 3 to 40% by weight. It is necessary to copolymerize with

Coatings formed from aqueous coatings made of copolymer salts and melamine in which the copolymerized amount of these compounds is 3% by weight or less have excellent chemical and physical properties because the crosslinking and curing properties due to heat are reduced. It is not possible to create a crosslinked coating film.

On the other hand, in the crosslinked cured coating film formed by baking a coating material made of a copolymer salt and melamine with a copolymerization amount of 40% or more of these compounds, uncrosslinked free particles are present. This is not preferable because a large amount of hydroxyl groups remain in the state, resulting in deterioration of performance such as water resistance, chemical resistance, and durability.

Specific examples of the monoethylenically unsaturated carboxylic acid (B) include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and dihydric acids among these acids and monoethylenically unsaturated carboxylic acids (B).
In the present invention, it is particularly preferable to use acrylic acid, methacrylic acid and itaconic acid.
It is necessary to copolymerize the copolymer in a proportion of 5 to 15% by weight in the form of a species or a combination of two or more species.

Since it is difficult to measure the water-solubility of copolymers in which the copolymerization amount of these acids is 5% by weight or less even if they are neutralized with a base, it is difficult to make the water-based thermosetting coating material that is the object of the present invention. On the other hand, a copolymer prepared by copolymerizing 15% by weight or more of an acid and neutralized with a base can be easily water-solubilized; A coating film formed from a curable coating material is crosslinked by heat treatment, and a large amount of free acid groups remain in the coating film, which is undesirable because its water resistance, durability, etc. are reduced.

The amount of acid copolymerized into the copolymer may be appropriately selected within the above-mentioned range depending on the purpose of use of the resulting coating material, but in particular, it may be selected while determining the degree of water solubility of the salt of the copolymer. It is desirable to determine the amount.

N-alkoxymethyl compound of unsaturated carboxylic acid amide Q
Specific examples include N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-propoxymethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide.

These compounds may be used alone or in combination of two or more.
It is necessary to copolymerize it into the copolymer in a proportion of 10% by weight.

These compounds not only increase the fluidity of the coating film formed from the aqueous thermosetting coating material containing the obtained copolymer during heating and improve the finished appearance of the coating film, but also promote cross-linking between these functional groups. A crosslinking reaction occurs between the reaction or other hydrophilic functional groups contained in the copolymer, such as hydroxyl groups, carboxyl groups, or aminoplasts, resulting in a coating film with good water resistance, solvent resistance, and chemical resistance. However, high temperatures are required when thermally crosslinking a coating film formed from an aqueous thermosetting coating material containing an excessively large amount of copolymer. So I don't like it.

Other copolymerizable monoethylenically unsaturated compounds D)
Specific examples include monoethylenically unsaturated monocarboxylic acids such as acrylic acid or methacrylic acid and monohydric alcohols such as methanol, ethanol, n-propanol,
1so-propatol, n-butanol, 1so-butanol, tert-phthanol, pentanol, hexanol, 2-ethylhexanol, lauryl alcohol, monoesters with C48 alcohols such as decyl alcohol, vinyl chloride, Vinyl propionate, vinyl acetate, acrylonitrile, methacrylonitrile, styrene, vinyltoluene, α-methylstyrene,
Acrylamide, N-methylol acrylamide,
Mention may be made of amide derivatives such as dia-7ton acrylamide.

35 in the form of one type or a combination of two or more of these compounds
It is necessary to copolymerize into the copolymer at a proportion of ~91% by weight, but it is necessary to select these comonomers in consideration of the characteristics of the crosslinked coating film formed from the coating material of the present invention. .

For example, in order to improve the finished appearance, durability during outdoor exposure, and water resistance of crosslinked coatings, among these comonomers,
In particular, it is best to select a comonomer based on an aromatic vinyl compound with a high refractive index such as styrene or vinyltoluene. are lower methacrylic acid alkyl esters alkylated with alkanols having 1 to 4 carbon atoms, such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, 1so-propyl methacrylate, n-butyl methacrylate, 1so-butyl methacrylate, tert
- It is better to choose comonomers based on butyl methacrylate.

Also 1. When the purpose is to improve the impact resistance and processability of the coating film, acrylates such as methyl acrylate, ethyl acrylate, and n-butyl acrylate, or 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, It is effective to select a comonomer mainly consisting of higher methacrylic acid esters such as dodecyl methacrylate and stearyl methacrylate.

The copolymer used in the present invention by combining the above monomers can be produced by a known solution polymerization method, but the polymerization solvent may be a monohydric saturated aliphatic alcohol having 1 to 5 carbon atoms, especially n-propanol. Tools, Impropatools and other ethylene glycol derivatives, especially methylselonlube, ethyl cellosolve, butyl cellosolve, dioxane, diacetone alcohol, acetone, etc. are water soluble, and the resulting copolymers have good solubility and are air polluting. 50% for organic solvents that do not easily cause pollution or these water-soluble solvents.
It is preferable to use a water-containing solvent containing less than % by weight of water.

An organic solvent solution of a copolymer can be prepared using a solvent other than the water-soluble organic solvent or water-containing organic solvent mentioned above as the organic solvent, but the organic solvent of the copolymer made using such an organic solvent In order to produce the aqueous thermosetting coating material of the present invention using a solvent solution, the organic solvent may be replaced with a water-soluble organic solvent, but one drawback is that the operation is complicated.

In addition, when using a water-containing organic solvent, the amount of water must be 50% or less, and when using an organic solvent with a water content of 50% or more, the copolymerization behavior of monomers and homogeneous polymerization tend to decrease. This is not desirable as it also causes the appearance of

In addition, it is necessary that the solid content concentration of the copolymer contained in the organic solvent solution of the copolymer is 65 to 90% by weight in terms of the organic solvent used.
If a solution of a copolymer in an organic solvent is diluted with water, a large amount of water must be added to produce an aqueous thermoset coating with a water content of 0 to 95% by weight of the total volatile components. (As a result, it becomes difficult to obtain good coating workability of the resulting water-based thermosetting coating material, especially when spray painting, and This is not preferable because coating defects such as wrinkles, sagging, and repelling are likely to appear in the coated film.

On the other hand, if the solid content concentration exceeds 90% by weight in terms of organic solvent, it is not preferable because its water dilutability decreases and a special dilution method becomes necessary.

When producing an organic solvent solution of the copolymer, a conventional polymerization method can be used to copolymerize the vinyl monomer, for example, at a polymerization temperature of 60-150°C,
For example, a radical polymerization initiator such as azobisisobutyronitrile, benzoyl peroxide, and cumene hydroperoxide, and a polymerization degree regulator such as 2-mercaptoethanol, thioglycolic acid, n-octylmercaptan, and n-dodecylmercaptan are used. It is better to do it.

The base used to partially or completely neutralize the carboxyl group-containing polymer contained in the organic solvent solution of the copolymer obtained as described above may be any water-soluble base. For example, caustic soda, caustic potash, ammonia or primary, secondary, tertiary aliphatic or alicyclic amines such as isopropylamine, n-butylamine, n-amylamine, diethylamine, diisopropylamine, n-dibutylamine, Diisobutylamine, triethylamine, n-)butylamine, monoethanolamine, ethylmonoethanolamine, beta-dimethylethanolamine, diethylethanolamine, cyclohexylamine.

Examples include morpholine and piperidine.

The amount of these neutralizing agents to be used needs to be selected depending on the concentration of carboxyl groups contained in the copolymer and the use of the aqueous thermosetting coating material, but usually the amount of carboxyl groups contained in the copolymer It is best to select according to the amount of base.

For example, when using a copolymer with a relatively low carboxyl group content, it is necessary to use a large amount of neutralizing agent, but for a copolymer with a relatively large amount of carboxyl groups, it is necessary to use a large amount of neutralizing agent. It can be sufficiently water-solubilized simply by adding the necessary amount of neutralizing agent.

The copolymer salt obtained by the method described above can be easily made into the aqueous coating material of the present invention by diluting it with water, but the gloss and finished appearance of the resulting coating film, as well as its water resistance and chemical resistance, can be easily made into the water-based coating material of the present invention. In order to improve the properties, highly hydrophilic unpolymerized monomers contained in the salt of the copolymer used, a polymerization catalyst, a molecular weight regulator, a polymerization inhibitor added in advance to the monomer used and its decomposition products, Alternatively, it is desirable to remove highly hydrophilic low molecular weight polymers that could not be made into high molecular weight polymers.

In order to remove these highly hydrophilic impurities, the solution of the copolymer obtained as described above may be treated with an anion exchanger such as zeolite, alumina, silica, activated carbon, or after adding a neutralizing agent. After the highly hydrophilic impurities contained in the copolymer are reacted with the anion exchanger by contacting with diatomaceous earth, an ion exchange membrane, etc., these anion exchangers may be removed from the copolymer.

The coating film formed from the aqueous coating material containing the copolymer salt obtained in this way has extremely good fluidity during baking and curing, resulting in a coating film with excellent aesthetic appearance. I can do it.

Furthermore, it is sufficient that the amount of neutralizing agent contained in the aqueous coating material is sufficient to stably dissolve or disperse the salt of the copolymer in the aqueous medium; Coating films formed from aqueous coating materials made using polymer salts may cause discoloration, and in such cases, copolymer salts treated with an anion exchange resin may be treated with a copolymer salt that has cation exchange properties. It may be treated with activated carbon, ion exchange resin, ion exchange membrane, zeolite, etc.

Examples of the N-alkoxymethylated melamine used in carrying out the present invention include water-soluble melamine derivatives such as an alkyl group, a methyl group, an ethyl group, a propyl group, and a butyl group. ,
Product name Nikaratsuku MW-12, Nikaratsuku MW-22,
Nikaratsuk MW-30, Nikaratsuk MW-40 (or above)
(manufactured by Sanwa Chemical Co., Ltd.), product name Sumitex M-
3. Sumimaru 70S1 Sumimaru M-100 (and above)
Examples include water-soluble melamine resins such as those manufactured by Sumitomo Chemical Industries, Ltd.).

The amount used is preferably 5 to 40 parts by weight per ioo parts by weight (in terms of solid content) of the above-mentioned copolymer salt.

A water-based coating material made using less than 5 parts by weight of melamine cannot form a coating film with excellent coating properties such as chemical resistance, water resistance, and solvent resistance. 40
Coating films made from aqueous paints containing a resin composition added in an amount greater than parts by weight are undesirable because they tend to become brittle and have reduced acid resistance.

The resin composition comprising the copolymer salt and N-alkoxymethylmelamine (water-soluble melamine resin) obtained by the method described above may optionally contain pigments such as titanium dioxide, zinc oxide, metal hydroxide, etc. Metal oxides, metal flakes, zinc chromium, sulfides, sulfates, carbonates, carbon black, silica, talc, organic lead, organic lake pigments, or other organic dyes can also be added.

These pigments and dyes are salts of the copolymers mentioned above.
It is preferable to use it in a range of 0 to 200 parts by weight based on parts by weight (in terms of solid content).

To prepare a colored paint by mixing the resin composition and pigment, first, the pigment, a solution of the copolymer that has been partially or completely neutralized in advance, and if necessary, water or a water-soluble organic solvent are mixed in a ball mill, sand mill, or A pigment paste is prepared by kneading with three rolls, and the remaining partially or completely neutralized copolymer solution and N-alkoxymethylmelamine are further mixed with water or a water-soluble organic solvent if necessary. Just adjust it.

As described above, in the present invention, since a water-soluble organic solvent for an acrylic polymer having a solid content concentration of 65% by weight or more is used, the resin composition as described above is finally coated with water or water and a water-soluble solvent. Even when diluted so that the ratio of organic solvent to water in the total volatile content of the material is 5/95 to 30/70 (wt%), it has good stability and a high solid content concentration. It can be used as a covering material.

In the conventional technology, when using a solvent mainly composed of water for an organic polymer, a dispersion stabilizer for the organic polymer had to be used together. By using an organic solvent solution of an organic polymer, the solid content is high, and the solvent is mainly water, and there is no color loss in the properties of the paint film formed from conventional organic solvent-based paints. The significance of the present invention, which has been able to create a water-based thermosetting coating material capable of forming a coating film with performance, is greater than the problems of pollution, resource conservation, hygiene, and other aspects.

The coating composition of the present invention can be applied by conventional spray painting, buffing,
It can be applied to the substrate by methods such as roll coating, dip coating, curtain claw coating, and electrostatic coating, and the crosslinking and curing of the coating film is approximately 120°C to 200°C, preferably 140°C to 180°C.
Bake hardening may be carried out at a temperature of 15 to 30 minutes at a temperature of .degree.

The aqueous thermosetting coating composition of the present invention can be applied to substrates such as metal, concrete, asbestos, wood, stone, textiles, leather, paper, etc., but in particular has excellent durability, flexibility, and a good coating surface. It exhibits particularly excellent performance when applied as a surface coating material to metal plates such as iron and aluminum that require special conditions.

The present invention will be explained in more detail with reference to Examples below, and all parts used in the Examples are parts by weight.

Example 1 In a three-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, 215 parts of ethyl cellosolve, 215 parts of butyl cellosolve, 100 parts of 2-hydroxyethyl methacrylate, 60 parts of itaconic acid, and 40 parts of N-butoxymethylacrylamide were added.
parts, 300 parts of styrene, 150 parts of n-butyl acrylate
100 parts of methyl methacrylate, 250 parts of 2-ethylhexyl methacrylate, 35 parts of 2-mercaptoethanol, and 6.5 parts of azobisisobutyronitrile were added, and the reaction was continued at 80°C for 1 hour. 2.5 parts of azobisisobutyronitrile was added to each half, and the reaction was continued for a total of 11 hours.

The resulting resin solution had a solid content of 70%, an acid value of 30.5, and a Gardner viscosity (25° C.) of Z6.

Add 5.7 parts of β-dimethylaminoethanol to 100 parts of the obtained resin solution, stir thoroughly to neutralize completely, and add 3 parts of water.
4.3 parts were added to obtain a resin solution (I) with a solid content of 50%.

Next, a white paint was prepared according to the following procedure.

First, 100 parts of acid value titanium (R-820: manufactured by Ishihara Sangyo ■), 40 parts of the above resin solution CI, and 40 parts of water were kneaded in a sand mill, and then 120 parts of the resin solution CI, MW-12: manufactured by Sanwa Chemical ■] was additionally mixed in 29 parts to prepare a white paint.

Next, apply this white paint to a Ford Cup A4 using only water.
The solution was diluted to 0 seconds/25°C, spray-painted on a zinc phosphate-treated steel plate (Bonderite #100 treatment, manufactured by Nippon Parkerizing Co., Ltd.), and cured at 150°C for 30 minutes.

From the effects shown in Table 1, this coating material has a paint solid content of 40% and a water content of 87% by weight among the total volatile components of the diluted paint.
It can be seen that the coating material has no risk of fire, has good storage stability and coating workability, and can form a coating film with particularly excellent appearance, chemical resistance, and weather resistance.

Comparative Example 1 A resin solution obtained by reacting in the same manner as in Example 1 except that 910 parts of ethyl cellosolve and 910 parts of butyl cellosolve was used had a solid content of 55%, an acid value of 26, and a Gardner viscosity (25°C) R. Ta.

To 100 parts of this 55% solids resin solution, 3.6 parts of β-dimethylaminoethanol was added and stirred thoroughly to neutralize completely, and then 6.4 parts of water was added to prepare a 50% resin solution (■).

Example 1 Preparation of white paint using the above resin solution [■]
I did it in the same way.

The resulting white paint was diluted with water alone to the same moisture content (87%) as the coating material used in Example 1.

The solid content of the paint at this time is 25%, which is 1040% in Example ☆
Compared to ☆, it decreased significantly.

Furthermore, the paint viscosity was significantly lower at 10 seconds/25°C for Ford Cup #4, and as a result of souffle painting using the same method as in Example 1, a uniform coating film could not be obtained, with significant sagging and flaking occurring. There wasn't.

In addition, when the resin solution (II, 1) was diluted with water to maintain the solid content of the coating material at 40% in the same manner as in Example 1,
The paint viscosity was extremely high for Ford Cup #4 over 5 minutes/25°C, making it impossible to spray paint.

On the other hand, in order to make a coating material that has a solid content of 40% and can be spray painted using a resin solution (III), it is necessary to use a dilution thinner that contains a large amount of organic solvent, and the organic solvent content in the resulting coating material was 30% or more, making it impossible to produce the covering material aimed at by the present invention.

Example 2 Into the same reaction vessel as used in Example 1 were added 215 parts of isopropyl alcohol, 215 parts of butyl cellosolve, 50 parts of 2-hydroxyethyl methacrylate, 20 parts of methacrylic acid, 77 parts of itaconic acid, 300 parts of styrene, and 50 parts of N-butoxymethylacrylamide. parts, ethyl acrylate 50
3 parts, 40 parts of 2-mercaptoethanol, and 3 parts of azobisisobutyronitrile were charged and reacted in the same manner as in Example 1 to obtain a solid content of 70.5%, an acid value of 50, and a Gardner viscosity (
An acrylic resin solution having a characteristic of -27 (25°C) was obtained.

To 100 parts of the obtained acrylic resin solution, 8.7 parts of β-dimethylaminoethanol was added and thoroughly stirred to completely neutralize it, and then 31.3 parts of water was added to obtain a 50% acrylic resin solution CI [[]. .

A white paint was prepared in exactly the same manner as in Example 1, except that this acrylic resin solution [■] and Nikalunk MW-22 as the melamine resin were used in place of Nikalunk MW-12 (manufactured by Sansho Chemical Co., Ltd.).

CP/B=1/1 Acrylic resin/Nicalac MW-
22 = 80/20 (solid content ratio)] Next, mix this white paint with water and Ford cup waste 4 for 30 seconds/
The solution was diluted to 25°C, spray-painted onto the same steel plate used in Example 1, and cured at 170°C for 20 minutes.

Table 2 shows the characteristics of this coating material, and as is clear from the results, this coating material has a paint solid content of 42%, and the water content in the total volatile components of the diluted paint is 85% by weight. There was no risk of fire and the storage stability was good.

In addition, the coating film performance was particularly excellent in appearance, physical properties, stain resistance, and corrosion resistance.

Comparative Example 2 In the same reaction vessel as used in Example 1, 910 parts of isopropyl alcohol, 910 parts of butyl cellosolve, 150 parts of 2-hydroxyethyl methacrylate, 50 parts of N-butoxymethylacrylamide, 310 parts of styrene, 455 parts of ethyl acrylate, and Itacon were added. 35 parts of acid, 15 parts of 2-mercaptoethanol, and 3 parts of azobisinbutyronitrile were charged and reacted in the same manner as in Example 1 to reduce the solid content to 54 parts.
．． An acrylic resin solution having the following characteristics was obtained: 5%, acid value: 14.8, and Gardner viscosity (25° C.).

After adding 2.7 parts of β-dimethylaminoethanol to 100 parts of the obtained acrylic resin solution and thoroughly neutralizing the mixture, 7.3 parts of water was added to obtain a 50% acrylic resin solution.

A white paint was prepared in the same manner as in Example 2 using this neutralized 50% acrylic resin solution.

Next, apply this white paint to Ford Cup/16.4 with water alone.
The mixture was diluted to a temperature of 30 seconds/25°C, spray-painted onto the same steel plate as used in Example 1, and cured at 170°C for 20 minutes.

The characteristics of this coating material are shown in Table 2, and as is clear from the results, this coating material has a paint solid content of 35% and a water content of 78% in the total volatile components of the diluted paint. The water content in the paint solids and total volatile components of the diluted paint was lower than the coating material of Example 2.

Furthermore, this coating material had poorer storage stability than the coating material obtained in Example 2, and also had poorer corrosion resistance in terms of coating film performance.

Example 3 In order to compare the water dilutability of the acrylic resin solutions obtained in Example 2 and Comparative Example 2, these acrylic resin solutions were
Table 3 shows the results of measuring the transparency and viscosity (cps) of the solution when it was completely neutralized with -dimethylaminoethanol and diluted with water.

As is clear from the results, the acrylic resin solution obtained in Example 2 had better water dilutability and water solubility than the acrylic resin solution obtained in Comparative Example 2.

Claims (1)

[Claims] 1 Hydroxyalkyl ester of monoethylenically unsaturated carboxylic acid (A) 3-40% by weight, monoethylenically unsaturated carboxylic acid B) 5-15% by weight, N-alkoxymethyl unsaturated carboxylic acid amide (C) 1-IO Weight %, other copolymerizable monoethylenically unsaturated compounds 035
A copolymer solution obtained by copolymerizing monomers in a proportion of ~91% by weight in an organic solvent or a water-containing organic solvent to a solid content concentration of 65 to 90% by weight; A coating consisting of a base capable of partially or completely neutralizing carboxylic acid, N-alkoxymethylmelamine in a proportion of 5 to 40 parts by weight per 100 parts by weight of the copolymer, water, and a water-soluble organic solvent. 1. An aqueous thermosetting coating composition, characterized in that the ratio of organic solvent to water in the total volatile components in the coating composition is from 5/95 to 30/70% by weight.