JPS5914071B2 - Water-based paint composition containing blocked isocyanate compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aqueous coating compositions containing novel blocked isocyanate compounds.

Water-dispersible polyurethane coating compositions, which are prepared by dispersing a resin composition obtained by reacting a polyester polyol produced from a polybasic acid and a polyhydric alcohol with a polyisocyanate compound in water using an appropriate emulsifier, are well known. It is being

The disadvantage of this composition is that since the formed film does not have a crosslinked structure, it has poor hardness, corrosion resistance, etc., and can only be used for special purposes. Also known is a water-based paint consisting of a two-component mixture of an active hydrogen-containing water-soluble resin and a blocked isocyanate compound as a crosslinking agent.

However, this blocked isocyanate compound has poor solubility in water and also poor compatibility with the coexisting active hydrogen-containing water-soluble resin, making it difficult to obtain a uniform resin solution. Therefore, the performance of the resulting coating film was also poor. A one-component water-soluble paint (Japanese Patent Publication No. 49-28653) obtained by reacting a partially blocked isocyanate compound with a carboxyl group-containing high molecular weight compound in order to improve the above-mentioned water-based paint! 0 or α containing blocked isocyanate groups
, a one-component aqueous coating composition obtained by copolymerizing a β-ethylenically unsaturated monomer and an α,β-ethylenically unsaturated monomer containing a carboxyl group and other ethylenically unsaturated monomers ( JP-A-501-58886) is also well known.

All of these one-component self-curing water-based paints contain active hydrogen and carboxyl groups in their molecules, which can be neutralized with basic substances to become water-soluble, making them ideal for electrophoretic painting, etc. Therefore, by baking the object after painting, a hardened coating film can be obtained. However, these coatings also have poor water resistance and chemical resistance, and
When overcoating was performed, there was a tendency for coloring to occur. The purpose of the present invention is to improve these drawbacks. After blocking the NCO group of an organic polyisocyanate using a specific blocking agent containing a carboxyl group; By reacting a high molecular weight active hydrogen-containing compound with a low acid value and converting some or all of the carboxyl groups contained in the reaction product into a quaternary ammonium salt or an alkali metal salt with a basic substance. It has been found that a water-soluble or water-dilutable blocked isocyanate compound can be obtained which can form a coating film having uniform and excellent weather resistance and highly improved coating properties, particularly water resistance and stain resistance.

The present invention is based on this knowledge.

That is, the present invention is based on the general formula (1) [wherein R is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group, a HOOC
-CH2- or HOOC-.

A represents an organic polyisocyanate residue, and M represents a residue of an active hydrogen-containing compound having a molecular weight of about 300 to 30,000 and an acid value of about 5 or less. l is 1 or more, and l (sum of 5m is 2
or more, n is an integer of 2 or more, and 1, m, n, a
is 5≦1+m+n 25 and 0.5<. ? Satisfies 4.0. Z represents a quaternary ammonium cation or an alkali metal cation. P, q is q/(p+q)×10
0 is about 100-40. ] This is a water-based paint composition containing a blocked isocyanate compound shown in the following. The above-mentioned blocked isocyanate compound is produced, for example, by the following method.

At least one of the NCO groups of the organic polyisocyanate has the general formula R-CH-COOH [wherein R is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group, HOOC]
-CH2- or HOOC-]
Partially blocked polyisocyanate compound 1 is obtained by combining a partially blocked isocyanate compound blocked with an oxycarboxylic acid and a high molecular weight active hydrogen-containing compound having at least two active hydrogen groups in one molecule and having an acid value of 5 or less.
The total number of free NCO groups in the molecule, blocked NCO groups, and active hydrogen groups in one molecule of the active hydrogen-containing compound is 5 to 25.
and the active hydrogen group/(free NCO group + blocked NCO group) of the active hydrogen-containing compound is about 0.
After reacting with each other at a ratio of 5 to 4.0, this reaction product is further treated with a basic substance to reduce the amount of -COOH groups in the reaction product to approximately 100 to 40 moles. The partially blocked isocyanate compound used in the present invention is one in which the free NCO groups of a polyisocyanate compound are partially blocked. Blocked diisocyanates, i.e., those with one free NCO group and one blocked NCO group, partially blocked triisocyanates, i.e., those with one free NCO group and two blocked NCO groups.
Examples include those having a CO group, or those having two free NCO groups and one blocked NCO group.

Such partially blocked isocyanates contain a polyisocyanate compound and a blocking agent in a ratio of about 0.0% to each NCO group of the polyisocyanate compound.
It is produced according to a conventional blocking reaction using 0.4 to about 0.7 mol. That is, a polyisocyanate compound and a predetermined amount of a blocking agent are mixed together in the presence of an inert solvent or without a solvent, and if necessary in the presence of a catalyst, generally for about 40 minutes.
C to about 100'C. At this time, the reactivity toward isocyanate is -COO
Since -0H groups are significantly larger than H, isocyanate groups are thought to react with -0H groups, but at high temperatures they also react with COOH groups, so 10
It is not preferable to raise the reaction temperature above 0'C. As the inert solvent in this reaction, any solvent normally used in blocking reactions of isocyanates can be used, such as esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and dioxane. , ethoxyethyl acetate, ethers such as tetrahydrofuran, toluene,
Aromatic hydrocarbons such as xylene, amides such as dimethylacetamide and dimethylformamide, and the like are used. The catalyst used in the partial blocking reaction may be any catalyst that is normally used in the blocking reaction of isocyanate compounds, such as tertiary amines (e.g. triethylamine, triethylenediamine, N-methylmorpholine). etc.), organometallic compounds (e.g.
tin octylate, zinc octylate, lead octylate, calcium naphthenate, dibutyltin dilaurate, tetrabutyl 1,3-diacetoxydistanoxane, etc.). In this partially blocked reaction product, unreacted free polyisocyanate compounds may remain, or compounds whose NCO groups have been completely blocked may be produced as by-products, and in the present invention, a portion containing them may be left as a by-product. Although blocked polyisocyanate compounds may be used in some cases, it is generally preferred to remove them by, for example, extraction, distillation, chromatography, precipitation, filtration, or the like. The amount of blocking agent used in the partial blocking reaction is as described above.
The amount is usually about 0.04 to about 0.7 mol per 1 mol of the partially blocked polyisocyanate, but more preferably, the unreacted free polyisocyanate compound remaining in the partially blocked reaction product and the compound in which all NCO groups have been blocked are added. When removed, the amount of polyisocyanate containing unreacted polyisocyanate compounds or (and) all NCO-blocked compounds is about 0.1 to about 0.3 moles. When using partially blocked isocyanates,
About 0.4 to about 0.6 mole. The organic polyisocyanate compound used in the present invention may be any known one, such as ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexocyanate, etc. Methylene 1,6-
Diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthylene diisocyanate,
4,41-methylenebis(phenyl isocyanate),
4,4'-ethylenebis(phenyl isocyanate),
ω,ω7-diisocyanate-1,3-dimethylbenzene, ω,ω5-diisocyanate-1,4-dimethylbenzene, ω,ω7-diisocyanate-1,3-dimethylcyclohexane, ω,ω7-diisocyanate-1,4-
Dimethylcyclohexane, 1methyl-2,4-diisocyanatecyclohexane, 4,4'-methylene-bis(
cyclohexyl isocyanate), 4,4'-ethylene-bis(cyclohexyl isocyanate), 3-isocyanatomethyl 3,5,5-trimethylcyclohexyl isocyanate, lysine diisocyanate, dimer acid diisocyanate, ω, ω7-diisocyanate diethylbenzene, ω, ω5-diisocyanate dimethyl Toluene, ω, ω5-diisocyanate diethyltoluene,
Di(2-isocyanatoethyl) fumarate, triphenylmethane triisocyanate, with an excess of the above-mentioned isocyanate compounds, such as ethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, 2,2,4-trimethyl- 1,3-pentanediol, hexamethylene glycol, cyclohexanedimethanol, hydrogenated bisphenol A, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, glycerin, sorbitol, seurose, pentaerythritol, etc. di- or polyisocyanates obtained by addition reaction with low-molecular polyols, polyisocyanates having biuret structures,
Also included are polyisocyanates having allophanate bonds.

Among these isocyanates, diisocyanates and triisocyanates are preferred, and among them, hexamethylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, ω, ω1-Diisocyanate dimethylbenzene ω, ω
Aliphatic or araliphatic isocyanates such as 5-diisocyanate dimethylcyclohexane or isocyanates obtained by addition reaction of an excess amount thereof with the above-mentioned low-molecular-weight polyol are preferred, but they are not comparable in terms of baking temperature. Optimal is ω, ω5-diisocyanate dimethylcyclohexane-based isocyanates that can be cured at relatively low temperatures.

These isocyanates may be used alone or in combination of two or more. The blocking agent used in the present invention has the general formula R-X-COOH [wherein R
is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group,
It is an α-oxy acid represented by HOOC-CH2- or HOOC-.

Specifically, for example, glycolic acid, hydroxymalonic acid, malic acid, mandelic acid, lactic acid, ethyl glycolic acid, propyl glycolic acid, isopropyl glycolic acid,
Examples include butyl glycolic acid and octyl glycolic acid. Among these protective agents, particularly preferred are glycolic acid and mandelic acid.

The high molecular weight active hydrogen-containing compound with an acid value of 5 or less used in the present invention has a molecular weight of about 350 to 30,0001, preferably 500 to 20,000, more preferably 1,
000 to 10,000 is preferable.

Examples of active hydrogen groups include -0H, -SH, -NH
Examples include one 2-NH group. One molecule may contain a single type of these, or two or more types thereof. In particular, so-called polyols having hydroxyl groups are preferred. One molecule must contain at least two active hydrogens. In particular, an average of 2 to 10 molecules per molecule is preferred. Examples of such high molecular weight active hydrogen-containing compounds include acrylic polymers (e.g., copolymers of hydroxyalkyl esters of acrylic acid or methacrylic acid, acrylamide copolymers, saponified vinyl acetate copolymers, etc.), polyethers, etc. Examples include polyols, polyester polyols, fatty acid-modified polyesters, polyester ether polyols, and epoxy resins. These polymer compounds have an acid value of 5 or less, preferably 3 or less, and more preferably 1 or less.

Acrylic polymers, polyether polyols, epoxy resins, etc. have essentially no acid value, so acid value is not a problem, but when using ester polyols,
You need to choose the type carefully. In the present invention, a partially blocked isocyanate compound having a free NCO group and at least one blocked NCO group and a high molecular weight active hydrogen-containing compound are combined to form a partially blocked isocyanate compound having a free NCO group and at least one blocked NCO group. The total number of NCO groups and active hydrogen groups in one molecule of the active hydrogen-containing compound is 5 to 25, preferably 8 to 15, and the active hydrogen groups of the active hydrogen-containing compound are partially blocked. Free NC of isocyanate compounds
Approximately 0.4 to 4 with respect to the sum of O group and blocked NCO group
．． 0, preferably about 1.0 to 3.0.

For example, in the case of a partially blocked isocyanate compound having one free NCO group and one blocked NCO group, a compound containing at least three active hydrogens per molecule is used. In addition, in the case of a partially blocked isocyanate compound having one free NCO group and two blocked NCO groups or two free NCO groups and one blocked NCO group, the compound containing at least two active hydrogens is used. In the present invention, all free NCs of partially blocked isocyanate compounds are
The O group reacts with an active hydrogen-containing compound.

For example, when the active hydrogen group is a hydroxyl group, a urethane bond is formed, whereas a blocked NCO group protected by a blocking agent having a carboxyl group remains as it is without reacting, and eventually becomes a blocked NCO group. A blocked isocyanate compound having both active hydrogen groups and a total of at least 3 carboxyl groups is produced. In the present invention, the reaction between the partially blocked isocyanate compound and the high molecular weight active hydrogen-containing compound is carried out in the same manner as the reaction between the polyisocyanate and the blocking agent, in the presence or absence of an inert solvent and a catalyst. 20 to about 100°C, preferably 3
It is carried out at 0 to 80°C, more preferably at 40 to 60°C.

As the inert solvent, those which can be used in the above-mentioned partial blocking reaction of the polyisocyanate compound are used as appropriate. As the catalyst, those that can be used in the above-mentioned partial blocking reaction are used as appropriate. If necessary, a hydrophilic solvent is added to the compound thus obtained in a proportion of about 0 to 1
After adding 00 weight 70 and diluting, add a basic substance to convert about 100 to 40 mol 701, preferably about 100 to 60 mol 70 of the COOH groups in the reaction product into a quaternary ammonium salt or alkali metal salt, and convert it into a water-soluble Or a water-dispersible blocked isocyanate compound.

Basic substances include inorganic bases (e.g., NI{3, Na0
H, K0H, Na2C03, K2C03, etc.), amines (e.g., trimethylamine, triethylamine, tripropylamine, tribenzylamine, dimethylaniline,
(pyridine, quinoline, picoline, piperidine, biperazine, pyrrolidine, morpholine, etc.)
Among these, tertiary amines are preferred. In the present invention, before the blocking agent is reacted with the polyisocyanate compound, some of the carboxyl groups may be converted into a salt by reacting with the basic substance. As a hydrophilic solvent,
Examples include alcohols such as ethyl alcohol, propyl alcohol, butyl alcohol, and diacetone alcohol, and glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and diethylene glycol monoethyl ether.

In this way, a blocked isocyanate compound having a blocked isocyanate group, a carboxyl group and an active hydrogen group in one molecule, and in which some or all of the carboxyl groups are quaternary ammonium salts or alkali metal salts, is obtained.

This compound does not require the use of other resin components or curing agents, and can be formed into a cured coating film by itself.

Moreover, it can be made into a uniform aqueous solution or a stable water-diluted solution, and if this aqueous solution or water-diluted solution is used for electrophoretic coating, a uniform electrodeposited coating can be obtained, and by heating it, a uniform electrodeposited coating can be obtained. As a result, it is possible to obtain a cured coating film that is homogeneous and has good physical properties. The heating temperature for baking is usually about 10
The temperature is 0 to 250°C, preferably about 120 to 220°C, more preferably about 140 to 200°C. The resin concentration in the aqueous solution used for electrophoretic coating purposes is usually about 7 to 15% by weight. When the above-mentioned compounds are used, in addition to the compounds and solvents, materials commonly used in paints, such as pigments, catalysts, leveling agents, etc., are appropriately added to form a water-based paint composition. As the dissociation catalyst, those that can be used in the above-mentioned partial blocking reaction can be used as appropriate, and distanoxane compounds can be particularly advantageously used. The coating film obtained by curing this water-based coating composition has extremely good water resistance and stain resistance compared to conventional water-based coatings because the hydrophilic carboxyl groups have already been consumed.

Furthermore, when a urethane paint or the like is applied over this coating, the upper coating will not be colored. The present invention will be specifically explained below using Examples.

In addition, the parts in the examples and ? is expressed on a weight basis. Example 1 ω,ω5-diisocyanate dimethylcyclohexane 3
0.08 part of tetrabutyl-1,3-diacetoxydistanoxane is dissolved in 88 parts of the solution, 90 parts of lactic acid is gradually added thereto, and the mixture is reacted at 50°C.

After reacting at 50° C. for 8 hours, unreacted diisocyanate is extracted and removed with n-hexane.

Obtain 260 parts of extraction residue. Add 86% of ethyl acetate to this extraction residue.
Add 7 parts to make a 7570 solution. In this way, a partially blocked isocyanate compound containing almost no unreacted diisocyanate is obtained.

46.8 parts of styrene, 30 parts of n-butyl acrylate,
Acrylic polyol obtained by dissolving 23.2 parts of 2-hydroxyethyl methacrylate in 100 parts of ethyl acetate and copolymerizing with azobisisobutyronitrile as a catalyst (acid value 01, molecular weight 5600, hydroxyl value 501 solid content) 231 parts of a partially blocked isocyanate compound solution was added to 1307 parts (50%) of the solution, and the reaction was continued at 70°C until free NCO groups disappeared. After the reaction is completed, ethyl acetate in the reaction mixture is distilled off under reduced pressure. Add 556 parts of ethylene glycol monoethyl ether to the distillation residue and dissolve it uniformly. To 100 parts of this resin solution with a solid content of 6070, 0.5 parts of tetrabutyl 1,3-diacetoxydistanoxane
5 parts of triethylamine and 20 parts of water were added and mixed with stirring to obtain a water-dilutable paint composition. The blocked isocyanate compound obtained in this example has the general formula (1) in which R is a methyl group, 1=1, m=1, n=10, a
=5, the value of n/a (1-Fm) is 1.0, q/(p+q
)×100 was 98.8.

Example 2 ω, ω7-diisocyanate dimethylcyclohexane 1
75% of adduct of mole and 3 moles of trimethylolpropane
Ethyl acetate solution (Takeda Pharmaceutical; Takenate D-120N)
76 parts of mandelic acid and 0.18 parts of dibutyltin dilaurate were added to 380 parts and reacted at 50°C for 8 hours.

After mixing 1,000 parts of castor oil and 444 parts of phthalic anhydride and reacting at 160°C for 2 hours, 402 parts of trimethylolpropane was added and the water produced at 200°C was removed with nitrogen gas until the acid value reached 5. Continue reacting until

To this was added 448 parts of ethyl acetate to obtain a resin solution having a solid content of 8,070, a molecular weight of 1,920, an acid value of 4, and a hydroxyl value of 140. 464 parts of a partially blocked isocyanate compound solution is added to 900 parts of this solution, and the reaction is continued at 65°C until there are no more free NCO groups. After the reaction is completed, the solvent ethyl acetate is replaced with ethylene glycol monoethyl ether to obtain a resin solution with a solid content of 60%. Obtained resin solution 100
After adding 0.5 part of tetrabutyl 1,3-diacetoxydistanoxane to the mixture, 20 parts of water was added, and while stirring, 2.8 parts of triethylamine was added to obtain a water-based paint composition. The blocked isocyanate compound obtained in Example 2 has the general formula () in which R is a phenyl group and 1=1.
5, m2 1.5, n=6, a=1.78, n/a(1+
The value of m) was 1.125, and the value of q/(p+q)XlOO was 100. Comparative example 1 ω, ω7-diisocyanate dimethylcyclohexane J
0.36 parts of tetrabutyl 1,3-diacetoxydistanoxane is dissolved in 6 parts of MoV, 130 parts of 2-hydroxyethyl methacrylate is gradually added thereto over 1 hour, and the mixture is then reacted at 65°C for 5 hours.

After the reaction is completed, unreacted diisocyanate is extracted and removed with n-hexane. 324 parts of extraction residue are obtained. After adding 138 parts of ethyl acetate to the extraction residue and uniformly dissolving it, 87 parts of methyl ethyl ketoxime was gradually added and the reaction was continued at 60°C until free NCO groups disappeared. 757 of α,β ethylenically unsaturated monomers containing blocked isocyanate groups
0 ethyl acetate solution is obtained. 55 parts of this block isocyanate-containing vinyl monomer solution, . 13 parts of 2-hydroxyethyl methacrylate, 24 parts of styrene, 16 parts of n-butyl acrylate, 6 parts of acrylic acid and 86 parts of ethyl acetate were mixed uniformly, 1 part of azobisisobutyronitrile was added thereto, and the mixture was heated at 75°C. Copolymerization was carried out for 10 hours.

After the reaction is complete, the solvent ethyl acetate is replaced with ethylene glycol monoethyl ether. Solid content 6070, acid value 2
A resin solution with a hydroxyl value of 8 (47 for a solid content of 10,070) and 34 (56 for a solid content of 10,070) was obtained. After adding 0.5 parts of tetrabutyl 1,3-diacetoxydistanoxane to 100 parts of the obtained resin solution, 20 parts of water was added, and while stirring, 5 parts of triethylamine was added to prepare an aqueous composition ( (as described in Japanese Patent Publication No. 49-28653). Comparative example 2 ω, ω5-diisocyanate dimethylcyclohexane J
87 parts of methyl ethyl ketoxime was gradually added dropwise to 6 parts of MoV over 1 hour.

After the dropwise addition was completed, the reaction was carried out at 60°C for 1 hour. After the reaction is completed, unreacted diisocyanate is extracted and removed with n-hexane.
281 parts of extraction residue are obtained. Add 92 parts of ethyl acetate to the extraction residue and dissolve it uniformly to obtain 75% of the monoadduct. Obtain a solution. Mix 85 parts of linseed oil and 15 parts of maleic anhydride and make 22
The maleation reaction is carried out at 0°C for 5 hours.

Next, the temperature was lowered to below 130°C, 20 parts of trimethylolpropane was added, and the esterification reaction was carried out at 130°C for 1.5 hours. can get. This polyol component 10
Add 73 parts of the partially blocked isocyanate solution to 0 parts, add 0.5 parts of tetrabutyl 1,3-diacetoxydistanoxane, continue the reaction at 80°C until there are no free NCO groups, and after the reaction is completed, the solvent is diluted with acetic acid. Ethyl was replaced with ethylene glycol monoethyl ether to obtain a 60% resin solution. 7.8 parts of triethylamine and 20 parts of water are added to 100 parts of this resin solution for neutralization to obtain a water-based paint composition. (Described in JP-A-50-8886). Example 3 (Coating Test) 124 parts of ethylene glycol monoethyl ether and 124 parts of water were added to 100 parts of the water-soluble composition of Example 1 to prepare a composition for electrodeposition coating.

This composition was put into a metal container as a bath liquid, a mild steel plate with a thickness of 0.8 mm treated with zinc phosphate was immersed to make an anode plate, and a DC voltage of 60 volts was applied between it and the metal container.
Electricity was applied for 1 minute. The temperature of the bath liquid was maintained at 30±1° C. during energization. This electrodeposited test plate was washed with water and heated at 180°C for 2 hours.
After baking for 0 minutes, a glossy and robust coating was obtained. The coating film performance test results are shown in Table 1. Example 4 113.7 parts of ethylene glycol monoethyl ether and 113.7 parts of water were added to 100 parts of the water-soluble composition of Example 2 to prepare a composition for electrodeposition coating. And so.

Electrodeposition was performed using this composition as a bath liquid under the same conditions as in Example 3, and baking at 180° C. for 20 minutes gave a glossy and robust coating. The results of the coating film performance test are shown in Table 1.
Comparative Example 3 110 parts of ethylene glycol monoethyl ether and 110 parts of water were added to 100 parts of the water-soluble composition of Comparative Example 1 to prepare a composition for electrodeposition coating.

Electrodeposition was performed using this composition as a bath liquid under the same conditions as in Example 3, and baking at 180° C. for 20 minutes gave a glossy coating. The coating film performance test results are shown in Table ζ. Comparative Example 4 To 100 parts of the water-soluble composition of Comparative Example 2, 106 parts of ethylene glycol monoethyl ether and 106 parts of water were added to prepare a composition for electrodeposition coating.

Electrodeposition was carried out using this composition as a bath liquid under the same conditions as in Example 3, and a glossy coating was obtained by baking at 180° C. for 20 minutes. The results of the coating film performance test are shown in Table 1.
Some of the coating films obtained in Comparative Examples 3 and 4 developed blisters in water resistance, boiling water resistance, alkali resistance, and acid resistance tests.

Regarding the coating film that caused this blistering, ASTM D-7
The diameter of the blister was investigated according to No. 14-56, but it could not be put to practical use. Example 5 76.1 parts of glycolic acid and 1.1 parts of dibutyltin dilaurate.
Dissolve 5 parts in 298.4 parts of dimethylformamide and
While maintaining the temperature of the mixture at 5°C, 222.3 parts of 3-isocyanatomethyl, 3,5,5-trimethylcyclohexyl isocyanate are gradually added over 7 hours.

The reaction is further carried out at 45°C for 15 hours. This reaction mixture was added to the polyester polyol of Example 2 (solid content: 10,070
) and continue the reaction at 60° C. until there are no free NCO groups. After the reaction was completed, 328.9 parts of ethylene glycol monoethyl ether was added to obtain a resin solution with a solid content of 6070. Tetrabutyl 1,3 to 100 parts of this solution
-0.5 parts of diacetoxydistanoxane, 5 parts of triethylamine, and 20 parts of water were added and mixed with stirring to obtain a water-based paint composition. The blocked isocyanate compound obtained in this example has the general formula (1) in which R is a hydrogen atom and l is a hydrogen atom.
=1, m=1, n26, a=3, the value of n/a(1+m) was 1.0, and the value of q/(p+q)×100 was 77.5. 124 parts of ethylene glycol monoethyl ether and 124 parts of water were added to the aqueous paint composition to prepare an electrodeposition paint composition. Example 6 222.3 parts of 3-isocyanatomethyl, 3,5,5-trimethylcyclohexyl isocyanate are heated to 700C with the addition of 1.1 parts of dibutyltin dilaurate.

Trimethylolpropane melted in this mixture 44.7
1 part is added over 1 hour, and the reaction is continued for an additional 3 hours at 70°C. Add 3 dimethylformamide to this reaction mixture.
After adding 35.1 parts of malic acid to make a uniform solution, 67.1 parts of malic acid was added.
Add 0 parts and continue the reaction at 45°C for 20 hours. Polyester polyol used in Example 2 (solid content 10070)
Add 320.5 parts and continue the reaction at 65°C until there are no free NCO groups. After the reaction was completed, 102 parts of ethylene glycol monoethyl ether was added to obtain a resin solution with a solid content of 6070. Add 100 parts of this solution to tetrabutyl 1,3-
0.5 parts of diacetoxydistanoxane, 9.3 parts of triethylamine, and 20 parts of water were added and mixed with stirring to obtain a water-based paint composition. The blocked isocyanate compound obtained in this example has the general formula (1) in which R is -CH2C
OOH, l=1.5, m=1.5, n::6′AO22
The value of n/a(1+m) is 1.0, q/(p+q)XlO
The value of O was 100. 130 parts of ethylene glycol monoethyl ether and 130 parts of water were added to the aqueous paint composition to prepare an electrodeposition paint composition. Example 7 The electrodeposition paints obtained in Examples 5 and 6 were electrocoated under the same conditions as in Example 3 and baked at 200° C. for 20 minutes to obtain a glossy and robust coating.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms,
Indicates an aryl group, HOOC-CH_2- or HOOC-. A represents an organic polyisocyanate residue, and M represents a residue of an active hydrogen-containing compound having a molecular weight of about 300 to 30,000 and an acid value of about 5 or less. l is an integer of 1 or more, the sum of l and m is 2 or more, n is an integer of 2 or more, and l, m, n, a are 5
≦l+m+n≦25 and 0.5≦n/a(l+m)≦
Satisfies 4.0. Z represents a quaternary ammonium cation or an alkali metal cation. p, q are q/(p+q
)×100 is about 100-40. ] A water-based paint composition containing a blocked isocyanate compound represented by the following.