JPS584591B2 - Film formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a coating, and more specifically, a hydrophilic non-aqueous emulsion colored coating composition is applied as a base coat, and a water-soluble coating composition is applied as a top coat thereon to form a transparent coating. The present invention relates to a method for forming a film using a two-coat, one-bake method for a so-called hydrophilic non-aqueous emulsion paint and a water-soluble paint, which is characterized in that a base coat and a top coat are coated in the same state and then heated and cured at the same time.

Conventionally, the 2-coat, 1-bake (hereinafter referred to as 2C-1B) method has been found to be superior to the 1-coat, 1-bake system in terms of gloss, chemical resistance, solvent resistance, outdoor weather resistance, etc. In fact, the 2C-IB method, which mainly uses thermosetting solution-type acrylic resin, is applied as a coating for finishing the exterior panels of automobile bodies and the like.

In recent years, the problem of pollution has become important in the paint field, and as one of the countermeasures against this problem, several water-soluble coating compositions have been developed from the aspect of reducing air pollution.

Naturally, therefore, a 2C-1B coating system using this water-soluble composition can be considered.

However, in the case of 2C-1B coating systems, water-soluble compositions generally lack suitability as base coats due to their properties.

That is, since water is used, evaporation is slow and the metal pigment does not stick well, causing problems in painting workability.

In addition, when a water-soluble composition is used as a top coat, the conventional method of using a solution-type acrylic resin composition as a base coat causes a repellency phenomenon of the top coat due to poor wetting between the top coat and the base coat. This poses a major obstacle in applying these compositions to 2C-1B coating systems.

Generally, this is because the resin is an aqueous solution and contains a large amount of polar groups such as hydroxyl groups and carboxyl groups to make it water-solubilized, so the polarity of the resin becomes very high and it does not interact with the base coat surface. A difference in surface tension occurs between the two, resulting in a repelling phenomenon.

As mentioned above, when using a water-soluble resin composition as a base coat, water is used as a medium, so
Evaporation is slow and metal pigments do not stick well, and if a water-based top coat is applied on top of it, the base coat may re-dissolve and return unevenly, resulting in poor paint film gloss and unsatisfactory film removal. I can't do it.

Therefore, as a result of intensive research, we have developed a solution that can be used in the 2C-1B method by using a composition mainly consisting of a hydrophilic non-aqueous emulsion for the base coat and a water-soluble resinous coating composition for the top coat. I have found that all problems can be solved.

That is, the present invention involves coating a base material with a thermosetting hydrophilic non-aqueous emulsion colored coating composition containing a hydrophilic organic liquid as the main dispersion medium, and then applying a thermosetting transparent water-soluble resin coating. The present invention relates to a method for forming a coating film, which is characterized in that the colored coating film and the transparent water-soluble resin coating film are simultaneously heated and cured after coating the composition.

Non-aqueous emulsions that use non-polar aliphatic hydrocarbons as the main dispersion medium are conventionally known, but the hydrophilic non-aqueous emulsions of the present invention use highly polar hydrophilic organic solvents as the main dispersion medium. This product holds metal pigments well, has good coating workability with no unevenness during spray painting, and is extremely suitable for base coats, and also has excellent base coat properties when a water-soluble composition is applied as a top coat. Due to its high polarity, the wet condition is good.
Furthermore, since the base coat is a hydrophilic non-aqueous emulsion, it has good solvent volatility and is dry to the touch, and there is no so-called uneven return due to blending with the top coat.
Overall, the coating exhibits an extremely excellent finish.

Furthermore, since the hydrophilic non-aqueous emulsion composition is an emulsion, it has a higher solids concentration during coating than conventional solution-type acrylic resin compositions, so less solvent is required to volatilize, and it can be applied as a top coat. Coupled with the water-soluble composition, it is also advantageous in terms of reducing air pollution, making it an extremely excellent coating method.

The basic concept of the hydrophilic non-aqueous emulsion used as a base coat in the present invention is the same as that of conventional non-aqueous emulsions in which the main dispersion medium is an aliphatic hydrocarbon solvent.

That is, the vinyl monomer is polymerized in an organic liquid that dissolves the vinyl monomer and does not dissolve the polymer formed from the monomer in the presence of a dispersion stabilizer that is soluble in the organic liquid, A stable dispersion of a vinyl polymer in which a polymer is dispersed in the organic liquid, wherein the organic liquid of the present invention has a solubility in water (number of grams dissolved in 100 g of water at 20 ° C.) of 5 or more, Furthermore, it is a hydrophilic organic liquid having a hydrogen bond number of -1.9 to 0 and a solubility parameter (sp value) of 9 to 13.

Organic liquids having a solubility in water of 5 or more include methyl alcohol, ethyl alcohol, is
o-furobyl alcohol, n-butyl alcohol, is
o-butyl alcohol, tert-butyl alcohol,
Alcohols such as tert-amyl alcohol, ketones such as acetone, methyl ethyl ketone, esters such as ethyl acetate, cellosolve acetate, carbitol acetate, methyl cellosolve acetate, methyl cellosolve, yarosolve, isoprovir cellosolve, butyl cellosolve, cyethylene glycol These include ether alcohols such as monobutyl ether.

The number of hydrogen bonds is -19 to 0 and the solubility parameter (sp value) is 9 to 13 when these are used alone or in combination of two or more.
You can use the following.

Of course, substances other than those listed above can be used in combination with one or more of the substances listed above, and the mixture has the following properties in each of the three items: solubility, number of hydrogen bonds, and solubility parameter (SP value). If the range is satisfied, it can be used.

Number of hydrogen bonds, SP value (solubility parameter) of organic liquid
was calculated based on the following literature.

Scruti6n theory and th
e c6mputef-Effective to
ols for the coatir1gs ch
emistR. C. Nelson et al. (S
Hell Development Company) J. Paint T+channel. 4 2No55
0,644 652 ('70) Representative examples are listed below.

The numbers in parentheses are density (25°C, g/ml), SP value, and number of hydrogen bonds, in that order.

Alcohols Methyl alcohol (0.7861, 1450, -1
9.80), ethyl alcohol (0.7846,1278,-18.
80), isopropyl alcohol (0.780・4,11.44
, -16.70), sec-butyl alcohol (os O 1 8,1
1. o 8, -17.50), n-butyl alcohol (0.8053, 1 1.
60, . -18.00), tert-butyl alcohol (0.79075,11
．． 24, -17.90), octyl algol (0.8287, 10.15, -
18.70): etc.

Ketones acetone (0.7846, 9.62, +12.50),
Methyl ethyl ketone (0.7992, 9.45, +1
0.50), methyl isobutyl ketone (0.7957, 8.・58,
, +10.50) etc.

Esters ethyl acetate (0.8939, 8.91, +8.40
), n-butyl acetate (0.8 7 5 7, 8.6 9
, +8. O O ), isobutyl acetate (0.8 6
5 8, 8.4 3 , +8.7 0 ), cellosolve azetate (0.9674, 9.35, +10.1
0), carbitol acetate (1.0042, 9.48, 10.5
0) etc.

Ether alcohols methyl cellosolve (0.9597, 11.68,00)
, Cellosolve (0.9247, 10.71, 0.0),
Isoprovil Cellosolve (0.9059,9.26,0
,0), Butyl Cellosolve (0.8959,9.87,0.0)
, diethylene glycol monobutyl ether (0.94
75, 9.79, 0.0) etc.

The number of hydrogen bonds in a mixed organic liquid is calculated using the following formula.

vi: Volume fraction νi: Number of hydrogen bonds (absolute value) The number of hydrogen bonds in parentheses above is Kiν including the sign
is the value of i.

The SP value of the mixed organic liquid is calculated using the following formula.

δM: SP value of mixed organic liquid Vi: Volume fraction δi: SP value The dispersion stabilizer has a solubility in water of 5 or more, a hydrogen bond number of -19 to 0, and an SP value of 9 to 13. It is a compound containing a component that is solvated by a hydrophilic organic liquid, and has a tolerance in the range measured using the solvent shown below (adding an organic liquid to 1 g of resin at 20°C and dissolving the resin, and The number of ml of the organic liquid required until the resin component does not dissolve but precipitates and the solution begins to become cloudy when the organic liquid is added.

・Ethyl alcohol tolerance = 1~oo ・Cellosolve tolerance: ∞O ・Cellosolve acetate tolerance: Not ∞.

Examples of these dispersion stabilizers include acrylic resins, alkyd resin mipolyesters, cellulose derivatives, and vinyl copolymers, modified products of these, and graft or block polymers of these and vinyl monomers. may be used alone or as a mixture.

In addition, amine resins can also be used as dispersion stabilizers, either alone or in combination with the above-mentioned dispersion stabilizers.

As an example, an acrylic resin-based dispersion stabilizer will be described in detail below.

That is, for example, 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, etc. (these are the first components of the dispersion stabilizer). A copolymer or a copolymer of two or more, or a copolymer consisting of 20% by weight or more of a first component and 80% by weight or less of a second component vinyl monomer listed below, where the second component is, for example, acrylic acid. , methacrylic acid and vinylpyrrolidone, acrylic esters, methacrylic esters (excluding the first component, such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc.).

) and vinyl esters of saturated carboxylic acids such as styrene, vinyl acetate and vinyl blobionate, ethylene, vinyl chloride and acrylamide derivatives such as acrylamide, methacrylamide, crotonamide, N-methylolacrylamide and diacetone acrylamide, etc. More than one species is appropriate.

The dispersion stabilizer contains the above components with a solubility in water of 5 or more, a hydrogen bond number of -19 to 0, and an SP value of 9 to 13.
In a hydrophilic organic liquid having a value of It is obtained by polymerization using a peroxide polymerization initiator such as tert-butylbar octoate.

Polymerization initiator concentration is 0.5 per 100 parts by weight of monomer
~10 parts by weight is preferred.

An active double bond may be introduced into the dispersion stabilizer. For example, a monomer having a carboxyl group is copolymerized in the dispersion stabilizer, and then glycidyl acrylate or glycidyl methacrylate is added to the dispersion stabilizer. There is a method of addition (or conversely, a dispersion stabilizer may be copolymerized with grindyl acrylate or grindyl methacrylate having a grindyl group, and then acrylic acid or methacrylic acid having a carboxyl group may be added thereto).

By introducing active double bonds into the dispersion stabilizer,
The dispersion stabilizer chemically bonds with the vinyl polymer that forms the dispersed particles, increasing the stability of the dispersion and also making it possible to improve the chemical and physical properties of the coating film obtained from the dispersion. .

The molecular weight of this dispersion stabilizer is preferably 1.0.
00 to 200,000.

If it is less than 1,000, the dispersion becomes unstable, and if it is greater than 200,000, the dispersion becomes extremely viscous and loses the characteristics of the dispersion system (high solids content, low viscosity).

The above is a detailed description of one example of the dispersion stabilizer, and of course the present invention is not limited to this dispersion stabilizer.

The main vinyl polymer forming the dispersed particles includes, for example, styrene, vinyltoluene, acrylic acid, methacrylic acid, acrylic acid alkyl ester (alkyl group C
nH2n+1 n=1 to 18), methacrylic acid alkyl ester (alkyl group CnH2n+1 n=1 to 1
8) Acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, N-methylolacrylamide, alkyl etherified product of N-methylolacrylamide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, methacryl 2-hydroxypropyl acid, other long chain esters of methacrylic acid or acrylic acid,
Examples include vinyl acetate and vinylpyridine.

The polymerization of the vinyl monomer that forms the dispersed particles has a solubility in water of 5 or more, and a hydrogen bond number of -19 to 0.
In a hydrophilic organic liquid having an SP value of 9 to 13, in the presence of a dispersion stabilizer, 2,2-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylparellonitrile) ), and peroxide polymerization initiators such as lauryl peroxide, penzoyl peroxide, and tert-butyl peroctoate.

Polymerization initiator concentration is 0 per 100 parts by weight of vinyl monomer.
．． 5 to 10 parts by weight is preferred.

In this case, the amount of the dispersion stabilizer is 3 to 70% by weight of the total amount of the vinyl monomer and the dispersion stabilizer (both are solid content ratios).

If it is less than 3% by weight, it will not be possible to produce a stable dispersion, and if it is more than 70% by weight, the dispersion will turn into a solution and lose its characteristics (high solid content, low viscosity).

The total concentration of the vinyl monomer and dispersion stabilizer in the dispersion is usually 30 to 70% by weight.

The reaction temperature is about 60-160°C.

A hydrophilic organic liquid (dispersion medium) having a solubility in water of 5 or more, a hydrogen bond number of -19 to 0, and an SP value of 9 to 13 and a dispersion stabilizer are placed in a reaction vessel, and the total amount of vinyl monomer is added. It is also possible to prepare a polymerization initiator and react for 1 to 15 hours to obtain a stable dispersion.
A mixture of a vinyl monomer (the dispersion stabilizer may be mixed in whole or in part with the vinyl monomer) and a polymerization initiator is dropped into a previously heated hydrophilic organic liquid for 1 to 9 hours, and then for 2 to 9 hours. It is also possible to obtain a stable dispersion by continuing the reaction for 7 hours.

In the colored coating composition for base coat of the present invention, a coloring agent is added to this hydrophilic nonaqueous emulsion, and if necessary, a plasticizer, a coating surface conditioner, a hardening agent, etc. can also be mixed therein.

Colorants include dyes, organic pigments, inorganic pigments, and metal pieces such as aluminum.

There are known plasticizers, such as low molecular weight plasticizers such as dimethyl phthalate and dioctyl phthalate, and high molecular weight plasticizers such as vinyl polymer plasticizers and polyester plasticizers, which can also be used by being mixed into the dispersion. However, it is also possible to dissolve it in the vinyl monomer during the production of the dispersion and distribute it in the dispersed particles of the produced dispersion.

Curing agents include crosslinking agents such as amine resins, epoxy resins, and isocyanate-terminated compounds.

As amino resin, melamine and/or urea-
A typical example is an alkylated formaldehyde compound.

Furthermore, when making a paint, a highly stable enamel product can be obtained by first dispersing pigments, colorants, etc. with a pigment dispersant and then mixing them into a hydrophilic non-aqueous emulsion.

Of course, any conventionally known coating method may be used.

It is sufficient to wet the minute metal additives, such as aluminum flakes, with an organic liquid and mix them into the hydrophilic non-aqueous emulsion composition.

The water-soluble resinous coating composition used as a top coat must satisfy various performances as a top coat, such as finish feel, gloss, durability, and chemical resistance.

Water-soluble resins that are the main components of water-soluble resinous coating compositions include acrylic resins and polyester resins.

When creating a water-soluble resin, hydrophilic groups (e.g.
There is a method of making the resin water-soluble by including a large amount of hydroxyl groups and carpoxyl groups, and a method of making the resin solubilized by making the carpoxyl group in the resin into a neutralized salt form with an amine or the like.

Vinyl monomers used in the synthesis of acrylic resins include, for example, styrene, vinyltoluene, acrylic acid, methacrylic acid, and acrylic acid alkyl esters (alkyl group C
nH2n+1 n=1-18), methacrylic acid alkyl ester (alkyl group CoH2n+1 n=1-18)
, acrylamide, methacrylamide, acrylonitrile, meccrylonitrile, N-methylolacrylamide, N=alkyl ether of methylolacrylamide (2-hydroxyethyl acrylate, acrylic acid')
2-hydroxypropyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, other long chain esters of methacrylic acid or acrylic acid, vinyl acetate, vinyl bilysine, polyethylene glycol monoacrylate, polymutylene glycol monomethacrylate, polypropylene glycol sheep noacrylate,
Examples include holipropylene-based recall monomethacrylate.

Generally known radical polymerization initiators are used for polymerization of these unsaturated monomers.

Furthermore, commonly known polyhydric alcohols, polybasic acids, and fatty acids are used as raw materials for polyester resins, and they are synthesized by known condensation methods such as bulk condensation methods and solvent condensation methods.

Although various methods can be used for the thermal crosslinking reaction of these water-soluble resins, crosslinking using a water-soluble amino resin is the main method.

In addition, when converting water-soluble resins used as top coats into paints, it is always possible to add dyes (color clears) and extender pigments to the extent that they do not cover the base coat, and other paint surface conditioners such as silicones may also be added. Of course it is possible.

In order to form an external finish coating, for example on an automobile body, by the method of the present invention, a hydrophilic non-aqueous emulsion colored paint is first applied to a primer-treated base coat to a dry coating thickness of 5.
After spray painting to a thickness of ~40μ and setting for about 1 to 20 minutes, spray paint a water-soluble clear resin composition on top of this so that the dry coating thickness is 10 to 100μ. After setting for 20 minutes,
Bake at a temperature of 120-200°C for 15-60 minutes, preferably 140-180°C for 125-40 minutes.

If an amino resin is used as a crosslinking agent, its amount is 5 to 60% by weight, in particular 25 to 4% by weight, based on the total amount of resin components including base enamel, top coat and amine resin.
0% by weight is preferable in terms of crosslinking density and coating film performance.

The coating thus obtained had excellent coating workability such as wetting, unevenness, and finished appearance, and also had good adhesion, solvent resistance, and acid resistance.

Next, the present invention will be specifically explained with reference to manufacturing examples and examples.

Both parts and percentages represent weight. Of course, the invention is not limited to these examples.

Production Example (A) Production of hydrophilic non-aqueous emulsion for base coat Production Example A-1 Synthesis of dispersion stabilizer (A) 70 parts of isopropyl alcohol and 30 parts of cellosol were refluxed, and the following monomers and polymerization initiator were added over 3 hours. Drop, after drip 2
Time aging was performed.

2-hydroxyethyl acrylate 80 parts acrylic acid 5 parts styrene
15 parts 2,2'-azobisisobutyronitrile 5 parts The resulting liquid was clear and had a non-volatile content of 50
%, and the Gardner viscosity (20°C) was X.

Synthesis of dispersion A mixture of 86 parts or more of isopropyl alcohol 100 parts dispersion stabilizer (A) is kept at the reflux temperature of isopropyl alcohol, the following monomers and polymerization initiator are added dropwise over 5 hours, and aged for 2 hours after the dropwise addition. I did this.

Acrylonitrile 88 parts 2-hydroxyethyl methacrylate 10 parts Methacrylic acid
2 parts 2,2' azobisisobutyronitrile 2 parts The obtained liquid was a milky white dispersion, and almost no sediment was observed even after it was left to stand for two weeks.

Non-volatile content is 50%, Gardner viscosity (25℃) is A-B
It showed very low viscosity.

Production Example A-2 Synthesis of Dispersion Stabilizer (B) The following mixture was kept at 80°C and glycidyl methacrylate (GMA) was added thereto to obtain a dispersion stabilizer (B) having an active double bond.

Dispersion stabilizer (A) 100 partsG
MA 0.5 part Paratertiary butylcatechol 0.01 part Dimethylaminoethanol 0.03 part Depending on the acid value after reaction and the molecular weight of the dispersion stabilizer (4), the number of dispersion stabilizers (B) may be 1 to 2 per molecule. was found to have an active double bond.

The obtained liquid was a transparent liquid with a slight yellowish tinge, and the Gardner viscosity (25°C) was Y.

Synthesis of Dispersion Using this dispersion stabilizer (B), a dispersion was synthesized as follows.

A mixture of 100 parts of isopropyl alcohol and 8 parts or more of dispersion stabilizer (B) was maintained at the reflux temperature of isopropyl alcohol, and the following monomers and polymerization initiator were added dropwise over 5 hours, and aged for 2 hours after the dropwise addition. .

Acrylonitrile 88 parts 2-hydroxyethyl methacrylate 10 parts Methacrylic acid
2 parts 2,2'-azobisisobutyronitrile 2 parts The obtained liquid was a milky white dispersion, and its stability on standing at room temperature was even better than the dispersion obtained in Production Example A-1.

Non-volatile content 51%, Gardner viscosity (25°C) is C-P
Met.

Production example A-3 Synthesis of dispersion stabilizer (C) Ethyl alcohol 60 parts Cellosolp
40 parts were refluxed, the following monomers and polymerization initiators were added dropwise over 3 hours, and after the addition, aging was performed for 2 hours to obtain a dispersion stabilizer (C).

2-Hydroxyethyl acrylate 50 parts Acrylic acid 5 parts Methyl methacrylate 20 parts Styrene
25 parts 2,2-azopis(2,4-dimethylvaleronitrile) 1.25 parts The obtained liquid was transparent and had a Gardner viscosity (20° C.) of Z.

Synthesis of dispersion stabilizer (D) 6 Introducing an active double bond into the dispersion stabilizer (C) Dispersion stabilizer (C) 100 parts glycidyl methacrylate 0.7 parts paratertiary butylcatechol 0.01 part dimethylaminoethanol
Keep at least 0.05 part at 80°C and add a dispersion stabilizer (
Based on the decrease in molecular weight and acid value of C), the reaction was continued until each molecule contained one active double bond to obtain a dispersion stabilizer (D).

Synthesis of dispersion Ethyl alcohol 100 parts Dispersion stabilizer (C) 21.5 parts Dispersion stabilizer (D) A mixture of 21.5 parts or more was kept at the reflux temperature of ethyl alcohol, and the following monomers and polymerization initiator were added for 5 hours. The solution was added dropwise and aged for 2 hours after the addition.

Acrylonitrile 35 parts Methyl methacrylate 30 parts Styrene
20 parts 2-hydroxyethyl methacrylate 10 parts methacrylic acid
5 parts 2,2'-azobisisoputilonitrile
The liquid obtained in 2 parts was a milky white dispersion, and had very good storage stability at room temperature.

The nonvolatile content was 50%, and the Gardgar viscosity (25°C) was P to Q.

Production example A-4 1 Synthesis of dispersion stabilizer (E) Neopentyl glycol 30 parts trimethylolpropane 10 parts phthalic anhydride in a reaction apparatus equipped with a water separator
20 parts adivic acid
10 parts tetrahydrophthalic anhydride
11 parts trimellitic anhydride
5 parts were charged, and the temperature was raised to 160°C with stirring, and further raised to 220-230°C over 3 hours.

Thereafter, the reaction is allowed to proceed for approximately 2 hours, and the reaction is terminated when the resin acid value reaches 30 to 45.

This resin was diluted by adding isopropyl alcohol (85 parts) to obtain a dispersion stabilizer (E).

The liquid thus obtained is transparent and has a Gardner viscosity of V
The nonvolatile content was 49%.

Synthesis of dispersion ethyl alcohol 100 parts dispersion stabilizer (E) 50 parts or more The mixture was kept at the reflux temperature of ethyl alcohol, the following monomers and polymerization initiator were added dropwise over 5 hours, and aged for 3 hours after the dropwise addition. Ta.

Acrylonitrile 20 parts Methacrylonitrile 5 parts Methyl methacrylate 40 parts Styrene
20 parts 2-hydroxyethyl methacrylate 10 parts methacrylic acid
5 parts 2,2'-azobisisobutyronitrile 5 parts The obtained liquid is a milky white dispersion and has good storage stability at room temperature.

The non-volatile content was 49% and the Gardner viscosity was between A and B.

Production Example A-5 Synthesis of dispersion stabilizer (F) Trimethylolpropane 33 parts phthalic anhydride 33.5 parts coconut oil fatty acid in a reactor equipped with a water separator
22.3 parts trimellitic anhydride
6.6 parts were charged, and the temperature was kept around 210°C for about 8 hours, and the reaction was stopped when the resin acid value reached 55±5.

Isopropyl alcohol (100 parts) is added to the obtained resin.
, glycidyl methacrylate (10 parts), dimethylamine ethanol (1 part), and paratertiary butylcatechol (0.1 part) were added and reacted under reflux. When the resin acid value reached 30, the reaction was stopped and dispersed. Stabilizer (F) is obtained.

The liquid thus obtained had a nonvolatile content of 50% and a Gardner viscosity of ST.

Synthesis of dispersion Cellosolve 100 parts Dispersion stabilizer
80 parts of a mixture of 50 parts or more
The following monomers and polymerization initiators were added dropwise over a period of 5 hours while the temperature was kept at 0.degree. C., and the mixture was aged for 3 hours after the addition.

Acrylonitrile 21
5 parts methyl methacrylate 36 parts styrene 36 parts 2-hydroxyethyl methacrylate 16 parts methacrylic acid
5 parts 2,2'-azobisisobutyronitrile 5 parts The resulting liquid is a milky white dispersion with good storage stability at room temperature.

The non-volatile content was 50% and the Gardnan viscosity was H to ■.

Production Example A-6 Synthesis of Dispersion Stabilizer (G) Isopropyl alcohol 40 parts Cellosolve 60 parts or more was kept at reflux temperature, and the following monomers and polymerization initiator were added dropwise over 4 hours.
After dropping, the mixture was aged for 3 hours to obtain a dispersion stabilizer (G).

Polypropylene glycol monoacrylate (molecular weight approximately 350) 40 parts acrylic acid
10 parts styrene
25 parts methyl methacrylate
26 parts 2,2'-azobisisobutyronitrile 5 parts The resulting liquid was transparent, had a nonvolatile content of 50%, and had a Gardner viscosity (at 25°C) of T.

Synthesis of dispersion n-butyl alcohol 30 parts Cellosolp 70 parts Dispersion stabilizer (G)
A mixture of 36 parts or more was kept at reflux temperature, and the following monomers and polymerization initiators were added dropwise over 5 hours, and aged for 4 hours after the addition.

Acrylonitrile 30 parts Methyl methacrylate 35 parts Ethyl acrylate 10 parts Styrene
25 parts 2 parts 2,2'-azobisisobutyronitrile The resulting liquid was a milky white dispersion, and had very good storage stability at room temperature.

The nonvolatile content was 50%, and the Gardner viscosity (25°C) was B.

Production example A-7 Synthesis of dispersion stabilizer H Ethyl alcohol 50 parts Cellosolve
While maintaining 50 parts or more at reflux temperature, the following monomers and polymerization initiator were added dropwise over 5 hours, and after the addition, aging was performed for 4 hours to obtain a dispersion stabilizer (H).

2-Hydroxyethyl acrylate 50 parts Methyl methacrylate 20 parts Styrene
30 parts 2,2-nitrile azobisisobutyronitrile 5 parts The resulting liquid is clear and has a non-volatile content of 50%.
The Gardner viscosity (25°C) was R-S.

Synthesis of dispersion Ethyl alcohol 50 parts Cellosolve 50 parts Dispersion stabilizer (H)
Keep at least 200 parts at reflux temperature and add the following monomers, polymerization initiator, and chain transfer regulator.

Acrylonitrile 30 parts Methacrylonitrile 10 parts Methyl methacrylate 20 parts Styrene
20 parts 2-hydroxyethyl methacrylate 10 parts methacrylic acid 1
0 parts 2,2'-azobisisobutyronitrile 1 part 1
-Octanethiol 0.1 part The obtained liquid is a milky white dispersion, has very good storage stability at room temperature, has a non-volatile content of 50%, and has a Gardner viscosity (25℃
) was MN.

Production example (B) Production of water-soluble resin for top coat Production example B-1 Styrene 40 parts Ethyl methacrylate 42 parts 2-hydroxyethyl acrylate 10 parts Acrylic acid
8 parts 2,2'-azobisisobutyronitrile 2 parts The above mixture was heated to 120°C.
of cellosolve over 2 hours, and after aging for 4 hours, 70 parts of cellosolve was distilled off under reduced pressure, neutralized with dimethylaminoethanol to the neutralization equivalent, and water was added to make a 60% solution. .

This solution had a Gardner viscosity of 2-21.

Production Example B-2 Styrene 15 parts N-butyl methacrylate 5 parts 2-hydroxyethyl acrylate 80 parts NN'-azobisisobutyronitrile 3 parts were subjected to a polymerization reaction in the same manner as in Production Example B-1, and the solvent was removed under reduced pressure. Remove and dilute with water6
It was made into a 0% solution.

This solution had a Gardner viscosity of w-X.

Production example B-3 Neopentyl glycol 30 parts trimethylolpropane 10 parts phthalic anhydride in a reactor equipped with a water separator
30 parts adipic acid
10.5 parts trimellitic anhydride
4.9 parts were charged, the temperature was raised to 160°C with stirring, and the temperature was further raised to 230°C over 3 hours.

After that, the reaction was carried out at 220°C to 230°C for 2 hours, and the acid value was 30.
When the temperature reached 40°C, the mixture was cooled to 100°C, 11.1 parts of trimellitic anhydride was added, and the mixture was heated to 180°C and reacted for 1 hour.

When the resin acid value reaches 90, cool it.

Trimethylamine was added to this resin for equivalent neutralization, and water was added to make a 60% aqueous solution.

The Gardner viscosity of this solution was Z.

Production example B-4 Trimethylolethane 33 parts phthalic anhydride 35.5 parts coconut oil fatty acid in a reactor equipped with a water separator
22.3 parts trimellitic anhydride
6. Add 6 parts and add 21 parts while stirring.
The temperature was raised to 0° C., and the mixture was allowed to react for about 8 hours. When the resin acid value reached 55, the reaction was stopped and the mixture was cooled.

This resin was neutralized by adding 1.2 equivalents of triethylamine, and water was added to make a 60% aqueous solution.

The Gardner viscosity of this solution was XY.

Next, a method for producing base coat and top coat paints will be described.

Manufacture of enamel paints for base coats Table 1 shows manufacturing examples of base coat enamel paints.

As for the manufacturing method, except for base 6, the colorant was first well dispersed in the amine resin by boiling the paint, and then the hydrophilic non-aqueous dispersion was gradually mixed into the colorant-dispersed amine resin while stirring well.

Base-6 uses a dispersion stabilizer (F) as a pigment dispersant to disperse the colorant, and then mixes the amine resin with it.
Subsequently, the hydrophilic non-aqueous dispersion was gradually mixed while stirring thoroughly.

The paint stock solution obtained in this way is then treated with thinner (cellosolve/isopropyl alcohol/carbitol acetate = 50/40/10 weight ratio) to a viscosity of 13 to 10.
The dilution was adjusted to 16 seconds (Ford Cup No. 4, 20°C).

■Hostor Balm Brown (trade name, manufactured by Hoechst) Production of top coat paint Manufacturing examples B-1 to B of water-soluble resin for top coat
-25 parts of each of the water-soluble amino resin Sumimaru M-40W (manufactured by Sumitomo Chemical Co., Ltd.) were added to 133 parts of each of the resins obtained in step 4, mixed, and water was added until the viscosity was 3.
The dilution was adjusted to give 0 to 35 seconds (food cup No. 4, 20° C.) to obtain Top-1 to Top-4.

Examples 1 to 7 The coating process of Examples 1 to 7 is shown in Table 2, and the finished coating state and film performance are summarized in Table 3.

The materials used for the coatings shown in Table 2 are a bonderite-treated steel plate that is coated with an electrodeposition coating commonly used for automobile coatings, baked, and then an amino alkyd resin paint (
This was also coated with a coating (usually used as an intermediate coating for automobile paint), baked, and then sanded with sandpaper.

The coating booth temperature was 20° C., and the coating was performed by hand using a spray gun at an air pressure of 5 kg/cm 2 .

1-stage base coat means that the film is applied once in a row to achieve the specified film thickness, and 2-stage means that the base coat is applied once, then set for 2 minutes, and then the base coat is applied on top of that to achieve the specified film thickness. The film thickness was obtained.

After applying the base coat, I let everything set for 3 minutes, and then applied the top clear coat in one stage.

After that, it was set for 10 minutes and then baked.

Of course, this coating method is standardly employed in general 2C-1B type automobile coating, and it goes without saying that this coating method does not limit the present invention.

Claims (1)

[Claims] 1. A thermosetting hydrophilic non-aqueous emulsion-type colored coating composition containing a hydrophilic organic liquid as the main dispersion medium is coated on a base material, and then a thermosetting transparent water-soluble resin is coated on the base material. 1. A method for forming a film, which comprises applying a color coating composition and then simultaneously heating and curing the colored coating film and the transparent water-soluble resin coating film. 2 The hydrophilic organic liquid has a solubility in water of 5 or more (2
0° C.), a hydrogen bond number of -19 to 0, and a solubility parameter of 9 to 13. 3 The hydrophilic organic liquid is methyl alcohol, ethyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, tert-butyl alcohol, tert-amyl alcohol, acetone,
Methyl ethyl ketone, ethyl acetate, cellosolve acetate, carbitol acetate, methyl cellosolve acetate,
3. The method for forming a film according to claim 2, wherein the film is formed by using methyl cellosolve, cellosolve, iso-propyl cellosolve, butyl cellosolve, and diethylene glycol monophthyl ether alone or in combination of two or more. 4. The dispersion stabilizer of the hydrophilic non-aqueous emulsion resin solution is selected from among acrylic resins, alkyd resins, polyesters, cellulose derivatives, vinyl copolymers, modified products thereof, and graft or block polymers of these and vinyl monomers. 2. The method for forming a film according to claim 1, wherein one or more of these, a mixture of one or more of these and an amino resin, or an amine resin alone is used. 5 The dispersion stabilizer of the hydrophilic non-aqueous emulsion resin solution is 2
-A homopolymer of hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, or a homopolymer thereof A copolymer of two or more of these, or 20% by weight or more of these and acrylic acid, methacrylic acid, vinylpyrrolidone, methyl acrylate, ethyl acrylate, butyl acrylate,
One or more vinyl monomers of methyl methacrylate, ethyl methacrylate, butyl methacrylate, styrene, vinyl acetate, vinyl propionate, ethylene, vinyl chloride, acrylamide, methacrylamide, crotonamide, N-methylolacrylamide, diacetonamide 80 5. The method for forming a film according to claim 1 or 4, wherein the film is a copolymer with % by weight or less. 6 The dispersion stabilizer for the hydrophilic non-aqueous emulsion resin solution is
A patent claim in which glycidyl acrylate and/or glycidyl methacrylate is added to a copolymer having a carboxyl group, or acrylic acid or methacrylic acid is added to a copolymer containing glycidyl acrylate and/or glycidyl methacrylate as one component. The film forming method according to item 1 or 4. 7 The components of the main vinyl polymer forming the dispersed particles of the hydrophilic non-aqueous emulsion resin solution are styrene, vinyltoluene, acrylic acid, methacrylic acid, alkyl acrylate ester (alkyl group CnH2n+1?=1-18), alkyl methacrylate Ester (alkyl group CnH2o+
1 n-1 to 18), acrylamide, methacurylamide, acryl and tolyl, methacrylonitrile, N-methylolacrylamide, alkyl etherified product of N-methylolacrylamide, 2-hydroxyethyl acrylate, acrylic acid/2-hydroxyfuro Claim 1, which is one or more of the following: 2-hydroxyethyl methacrylate, 2-hydroxydipropyl methacrylate, other long-chain esters of methacrylic acid or acrylic acid, vinyl acetate, and vinylbilysin. The film forming method described in Section 1. 8. The film forming method according to claim 1, wherein the hydrophilic non-aqueous emulsion colored coating composition contains at least a hydrophilic non-aqueous emulsion resin solution and a colored pigment or a metal powder pigment. 9. The film forming method according to claim 1, wherein the thermosetting transparent water-soluble resinous coating composition contains a water-soluble acrylic resin or a water-soluble polyester resin as a main component. 10 The water-soluble resin of the thermosetting transparent water-soluble resinous coating composition is styrene, vinyl toluene, acrylic acid, medacrylic acid, acrylic acid alkyl ester (alkyl group CiH2n+1n=1 to 18), methacrylic acid alkyl ester (alkyl Group CnH2n+1 n=1-18)
, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, N-methylolacrylamide, alkyl ether of N-methylolacrylamide, 2-hydroxyethyl acrylate, acrylic acid 2
-Hydroxypropyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, other long chain esters of meccrylic acid or acrylic acid, vinyl acetate, vinylpyridine, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate , one of polypropylene glycol monomethacrylate
10. The method for forming a film according to claim 1 or 9, which is a radical polymer of a species or two or more kinds of uncelled monomers. 11. The film forming method according to claim 1 or 9, wherein the water-soluble resin of the thermosetting transparent water-soluble resinous coating composition is a condensate of a polyhydric alcohol, a polybasic acid, and a fatty acid. 12. The film forming method according to claim 1 or 9, wherein a thermal crosslinking reaction using a water-soluble amine resin is used to cure the transparent water-soluble resin coating film. 13 5 to 60% by weight of amino resin is blended into the hydrophilic non-aqueous emulsion type colored coating composition and the transparent water-soluble resinous coating composition based on the total amount of the amino resin and the resin components in each composition. Claim 1 consisting of
The film forming method according to item 8 or 9. 14. The film forming method according to claim 1, wherein the colored coating film and the transparent water-soluble resin coating film are cured by heating at the same time at 120 to 200°C for 15 to 60 minutes.