JP2731860B2 - Resin composition for coating - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel coating resin composition, and more particularly to a coating having reduced heat loss upon baking and improved corrosion resistance and low-temperature curability. The present invention relates to a resin composition for use.

2. Description of the Related Art Conventionally, a curable composition in which a synthetic resin having a hydroxyl group or an amino group is combined with a crosslinking agent, for example, a composition in which an epoxy-polyamine resin having a hydroxyl group is combined with a blocked polyisocyanate as a crosslinking agent (For example, Japanese Patent Application Laid-Open No.
JP-A-5-55, and a composition comprising a combination of a synthetic resin having active hydrogen and a transesterifiable crosslinking agent.
No. 80436) is known.

However, the composition using the blocked polyisocyanate has a problem that the blocking agent dissociates from the polyisocyanate during heat curing and volatilizes in the air, so that the blocking agent does not contribute to the formation of a coating film, but also causes environmental pollution. In addition, the composition using a transesterifying cross-linking agent has a problem that the acid concentration increases due to hydrolysis of the cross-linking agent, and the cross-linking curability is lowered accordingly, particularly when used in an aqueous system.

Further, a composition comprising a combination of a synthetic resin having a polymerizable unsaturated group and a blocked polyisocyanate using an alcohol containing an α, β-ethylenically unsaturated double bond as a blocking agent (for example, JP-A-59-122564) However, the block polyisocyanate has an ester bond, and thus has a drawback that the acid concentration is easily increased by hydrolysis of the crosslinking agent and a crystal structure is easily formed particularly when used in an aqueous system. In addition, since the alcohol containing an α, β-ethylenically unsaturated double bond dissociated from the blocked polyisocyanate by heating remains in the coating film to increase the hydroxyl group concentration, there was a disadvantage that the coating film performance such as corrosion resistance was poor. .

On the other hand, in a polybutadiene-based or unsaturated fatty acid-modified resin-based resin that cures by oxidation or thermal polymerization, the coating properties such as corrosion resistance are not sufficient, and a large amount of unsaturated groups remain in the cured coating, and the polymerization proceeds over time. Of coating film properties such as deterioration over time due to the progress of coating, and the difference in curability between the coating film surface and the inside when coating a thick film with a thickness of 50 microns or more is large, and abnormalities such as blemishes on the surface are likely to occur. There is. In addition, a self-curing binder component (Japanese Patent Application Laid-Open No. 53-84035), in which a resin contains an α, β-ethylenically unsaturated double bond as a functional group, and a cross-linking method of thermally polymerizing the same, is used. α, β
An α, β-ethylenically unsaturated double bond formed by premixing an amino compound with an ethylenically unsaturated double bond by Michael and releasing the amino compound from the adduct by baking to have an active hydrogen group A binder component that employs a crosslinking method of reacting with a resin (JP-A-55-31889) is known. However, since the former binder component is a polymerization reaction between α, β-ethylenically unsaturated double bonds, baking at a high temperature (about 180 ° C. or more) is required, and curing inhibition is caused by oxygen and curing of the coating surface is insufficient. On the other hand, the latter binder component has the disadvantage that the cured film is easily discolored and the amino compound volatilizes from the coating film during the curing process, which is not preferable in terms of safety and health.

Means for Solving the Problems For this reason, the present inventors have made it possible to provide a coating resin composition which has little environmental loss due to low heat loss, and has improved corrosion resistance and low-temperature curability. As a result of intensive studies on the purpose, surprisingly, 3-alkoxyalkyl-3- obtained from the reaction between a (meth) acrylamide compound having an alkoxyalkyl group and an isocyanate group has been obtained.
The present inventors have found that a coating resin composition containing a resin having a specific amount of a (meth) acryloyl-ureido group can achieve the above object, and have completed the present invention.

Thus, according to the present invention, the general formula Wherein R ¹ is a hydrogen atom or a methyl group, and R ² has 1 to 1 carbon atoms.
And R ³ represents an alkyl group having 1 to 10 carbon atoms. A resin having an average molecular weight of 0.6 or more per molecule and having a number average molecular weight of 800 to 50,000 (hereinafter, abbreviated as "resin A") is represented by the following formula: A resin composition is provided, further comprising a hydroxyl group-containing resin having 1.4 or more primary or secondary hydroxyl groups per molecule and having a number average molecular weight of 600 to 50,000 (hereinafter referred to as “resin B”). Abbreviated as ")" and having an average of one or more groups represented by the general formula (I) per molecule,
And a resin having a number average molecular weight of 400 to 30,000 (hereinafter abbreviated as “resin C”).

The group represented by the general formula (I) in the present invention (hereinafter, referred to as “
Abbreviated as "ureido group of formula (I)". ) Is a polyfunctional group having both an α, β-ethylenically unsaturated double bond that can be added to a hydroxyl group and an alkoxy group that can also be ether-exchanged or self-condensed with the hydroxyl group.

 First, the resin A in the composition of the present invention will be described.

Resin A contains the ureido group of formula (I) in an average of 0.1 per molecule.
It is a self-crosslinkable resin having about 6 to 120 pieces. From the viewpoint of curability, the resin A has an average of about 2 to 200 per group of the group represented by the formula (I) and the primary or secondary hydroxyl group which may be optionally present. Preferably, there is.

Resin A is, for example, a compound represented by the general formula: Wherein R ¹ , R ² and R ³ are as defined above. The adduct obtained by reacting N-alkoxyalkyl (meth) acrylamide represented by the formula (hereinafter abbreviated as “adduct a”) is introduced into a hydroxyl group-containing resin. The introduction can be carried out by a urethanization reaction between the remaining isocyanate groups in the adduct a and the hydroxyl groups in the hydroxyl group-containing resin. The resin A is obtained by reacting all isocyanate groups of the polyisocyanate with N-alkoxyalkyl (meth) acrylamide represented by the general formula (II) (hereinafter, abbreviated as “compound of the formula (II)”). (Hereinafter, abbreviated as “addition b”).

As the polyisocyanate used in the production of the resin A, a polyisocyanate having any timing such as aliphatic, alicyclic, and aromatic can be used.
4- and 2,6-tolylene diisocyanate, m-xylylene diisocyanate, methylcyclohexane-2,4-diisocyanate, 1,3-isocyanatomethylcyclohexane, isophorone diisocyanate, diphenylmethane-4,4'-diisocyanate, trimethylhexamethylene diisocyanate Polyisocyanate compounds such as hexamethylene diisocyanate, tetramethylene diisocyanate, and polymethylene polyphenyl polyisocyanate, and excessive amounts of these polyisocyanate compounds may be added to ethylene glycol, propylene glycol, trimethylolpropane, hexanetriol, castor oil, etc. And polyisocyanates obtained by reacting a compound containing a molecularly active hydrogen.
More than one species can be used in combination.

In producing the resin A, in the compound of the formula (II) reacted with the above-mentioned polyisocyanate, R ² has 1 to 1 carbon atoms.
If 4 alkylene group may be a branched be linear, such as methylene group, ethylene group, n- propylene, n- butylene and the like, R ³ is the number of carbon atoms
An alkyl group having 10 or less, more preferably an alkyl group having 4 or less carbon atoms, which may be linear or branched, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n -Butyl group, isobutyl group, t-butyl group, n-hexyl group, 2-ethylhexyl group, n-decyl group and the like.

Representative examples of the compound of the above formula (II) include Nn-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, N-methoxymethylacrylamide and the like, and these may be used alone or in combination. These can be used in combination.

The reaction between the polyisocyanate and the compound of the formula (II) is a reaction between the isocyanate group and the NH group in the compound of the formula (II), and is usually carried out in an inert organic solvent using an isocyanate addition catalyst and radical polymerization. This can be achieved by reacting at a reaction temperature of 80 ° C to 150 ° C, preferably 100 ° C to 120 ° C for 5 to 30 hours in the presence of an inhibitor.

The mixing ratio of the polyisocyanate and the compound of the formula (II) used in this reaction is as follows:
It is preferable that the number of remaining isocyanate groups after the reaction be stoichiometrically one or less per molecule.

The inert organic solvent that may be used in the above reaction is one that is inert to the isocyanate and can dissolve or disperse the polyisocyanate, the compound of the formula (II) and the reaction product of both. Representative examples include aromatic hydrocarbons such as xylene and toluene, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetone; ethers having no hydroxyl group such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; and cyclic ethers such as dioxane. And the like.

As the isocyanate addition catalyst used in the above reaction, typically, an organic lead compound such as lead octylate and lead acetate, an organic zinc compound such as zinc naphthenate, an organic manganese compound such as manganese acetate, dibutyltin dilaurate,
Organotin compounds such as dibutyltin diacetate; organometallic compounds such as organic sodium compounds such as sodium oxalate; tertiary amines such as triethylamine, tri-n-butylamine and pyridine; and quaternary amines such as cetyltrimethylammonium bromide and tetraethylammonium bromide. And the like. Examples thereof include a quaternary ammonium organic acid salt and an alkali metal compound such as sodium hydroxide and potassium hydroxide.

The compounding amount of the isocyanate addition catalyst requires a larger amount than in the case of a reaction between a normal hydroxyl group and an isocyanate group.For example, when dibutyltin dilaurate is used as an addition catalyst, the reaction between the hydroxyl group and the isocyanate group is required. Is generally about 500 ppm, but in the reaction between the polyisocyanate and the compound of the formula (II), 5000 ppm to 500 ppm
It is required to be about 00 ppm, which is 10 to 100 times the amount used in the case of a normal reaction between a hydroxyl group and an isocyanate group.

As the radical polymerization inhibitor that can be used in the above reaction, those that suppress a radical polymerization reaction due to heat are used, and as typical examples, parabenzoquinone, methoxyphenol, 2,6- or 2,5-dichloro-p- Benzoquinone,
Diphenylpicrylhydrazyl, hydroquinone, tert
-Butyl-hydroquinone, methylhydroquinone, phenothiazine, N, N'-di-2-naphthyl-P-phenylenediamine, and the like. These radical polymerization inhibitors are preferably used in the range of 1,000 to 50,000 ppm.

The adduct a or the adduct b can be obtained by the reaction between the polyisocyanate and the compound of the formula (II). The adduct b can be used as the resin A as it is,
The adduct a is further subjected to a urethanization reaction of a hydroxyl group-containing resin,
Resin A can be obtained.

The hydroxyl group-containing resin to be reacted with the adduct a has one hydroxyl group.
Known resins can be used without particular limitation as long as the resin has an average of 2 or more, preferably 2 to 200 in the molecule, and a number average molecular weight of 600 to 50,000. Specifically, for example,
Acrylic polyols, polyester polyols, polyether polyols, alkyds, caprolactone polyols, epoxies, urethane polyols and the like can be mentioned as the hydroxyl group-containing resin. These hydroxyl group-containing resins are, for example, polycaprolactone diol which is a reaction product of a diol such as ethylene glycol with ε-caprolactone, polypropylene glycol, polytetramethylene glycol, dimer acid polyamide, carboxyl-terminal acrylonitrile-butadiene copolymer,
It may be modified by a modifier such as an adduct of acrylic acid or methacrylic acid and ε-caprolactone.

The reaction between the adduct a and the hydroxyl group-containing resin is usually
This can be achieved by heating at a reaction temperature of 0 ° C. to 150 ° C. for about 1 to 30 hours in an inert organic solvent in the presence of an isocyanate addition catalyst and a radical polymerization inhibitor.

The mixing ratio of the adduct a and the hydroxyl group-containing resin used in this reaction is not particularly limited as long as all isocyanate groups in the adduct a react with the hydroxyl group-containing resin, but usually, adduct a / hydroxyl group The ratio of the contained resin is preferably in the range of 0.5 / 99.5 to 90/10, more preferably 10/90 to 70/30 in terms of resin solid content weight ratio.

The inert organic solvent that can be used in the above reaction is one that is inert to isocyanate groups and that can dissolve or disperse the adduct a, the hydroxyl-containing resin, and the reaction product of both. Representative examples include those exemplified as inert solvents which can be used in the reaction of the polyisocyanates with the compound of formula (II).

As the isocyanate addition catalyst and the radical polymerization inhibitor that can be used in the above reaction, a catalyst and an inhibitor that can be used in the reaction between the polyisocyanate and the compound of the formula (II), respectively, can be used. The amount of the isocyanate addition catalyst to be used is preferably about 1/10 to 1/100 of the amount used in the reaction between the polyisocyanate and the compound of the formula (II).

The resin A obtained as described above has an average of 0.6 or more ureido groups of the formula (I) per molecule, preferably 1
It is desirable that the total of the primary or secondary hydroxyl group and the ureido group of the formula (I) is at least two per molecule on average, and the number of the primary urea group and the primary or secondary hydroxyl group of the formula (I) The ratio is preferably ureido group / hydroxyl group of formula (I) = 1/0 to 1
/ 3, more preferably in the range of 1 / 0.3 to 1/2, from the viewpoint of curability. When the average of the ureido groups of the formula (I) is less than 0.6 per molecule, the self-crosslinking property tends to be insufficient.

The resin A has a number average molecular weight of 800 to 50,000, preferably 10
It is necessary that the number average molecular weight is 800 to 30,000.
If it is less than 50,000, it is difficult to synthesize it. On the other hand, if it exceeds 50,000, good coated surface smoothness cannot be obtained.

 Next, the resin B in the composition of the present invention will be described.

Resin B is a hydroxyl-containing resin having about 1.4 to 430 primary or secondary hydroxyl groups per molecule and a number average molecular weight of 600 to 50,000. The resin B is used in combination with the resin C. The resin B may or may not contain the ureido group of the formula (I). It is preferable that the total amount of (I) and the ureide group is about 2 to 200 per molecule on average.

When the resin B does not have the ureido group of the formula (I), it is preferable that the resin B has about 2 to 200 hydroxyl groups per molecule. And a hydroxyl group-containing resin.

When the ureido group of the formula (I) is contained in the resin B, for example, the above-mentioned hydroxyl group-containing resin and the adduct a are mixed so that the average number of ureide groups of the formula (I) is less than 0.6 per molecule. And the reaction may be performed under the same conditions as in the reaction between the adduct a and the hydroxyl-containing resin in the production of the resin A.

Resin B has a number average molecular weight of 600 to 50,000, preferably 1,000 to
When the number average molecular weight is less than 600, the corrosion resistance becomes insufficient, and when it exceeds 50,000, the smoothness of the coated surface is poor.

Next, the resin C used in combination with the resin B in the composition of the present invention will be described.

The resin C is a resin having a number average molecular weight of 400 to 30,000 containing an average of about 1 to 80 ureido groups per molecule of the formula (I), for example, a compound of the formula (II) and a mono- or polyisoyanate. And a reaction product of the adduct a with a compound or resin containing a hydroxyl group.

Examples of the mono or polyisocyanate include benzene, 1- (1-isocyanato-1-methylethyl)-
Examples thereof include 4- (1-methylethenyl) and the polyisocyanates exemplified above, and compounds having at least one isocyanate group in a molecule obtained by partially blocking the polyisocyanate with a blocking agent such as an alcohol. As the compound or resin containing a hydroxyl group, which forms a reactant with the adduct a, a compound or a resin containing about 1 to 80, preferably about 2 to 40 hydroxyl groups per molecule in the compound or resin. Examples thereof include ethylene glycol, propylene glycol, trimethylolpropane, hexanetriol, castor oil, and a hydroxyl-containing resin that is reacted with the adduct a in the production of the resin A.

The production of the adduct of the compound of the formula (II) with the mono- or polyisocyanate can be carried out under the same reaction conditions as in the production of the adduct a. The reaction product of the adduct a with the hydroxyl group-containing compound or resin can be produced under the same reaction conditions as in the reaction of the adduct a with the hydroxyl group-containing resin in the production of the resin A.

In the resins A, B, and C obtained as described above and above, the resin A can be used alone because it has self-crosslinking property, but if necessary, the resin C, A block polyisocyanate resin, a melamine resin, or the like can be blended and used, and an acrylic resin, a polyester resin, an epoxy resin, or the like can be blended as a modifying resin. Further, the resin B does not have self-crosslinking property but is insufficient, so that it needs to be used in combination with the resin C. The mixing ratio of the resin B and the resin C may be appropriately selected.
The ratio of the number of the primary hydroxyl groups is preferably ureido group / hydroxyl group of formula (I) = 1 / 0.02 to 1/3, more preferably 1 / 0.3 to 1 /
It is desirable to be within the range of 2 from the viewpoint of curability. The mixing ratio of the resin B and the resin C is usually resin B / resin C = 95/5 to 5/95, preferably 90/10 to 3 in terms of resin solid content weight ratio.
Used in the range 0/70. In the combined use system of the resin B and the resin C, a crosslinking agent such as a block polyisocyanate resin and a melamine resin and a modifying resin such as an acrylic resin, a polyester resin and an epoxy resin can be blended and used as required.

The coating resin composition according to the present invention may be of an organic solvent type or an aqueous type.

In the case of an aqueous system, the resin is neutralized with an organic acid such as acetic acid or the like to disperse or disperse in water. What is necessary is just to introduce | transduce groups for water-solubility, such as a carboxyl group which can be made water-soluble.

When a film is formed using the thus obtained resin composition for coating of the present invention, a curing catalyst is blended into the resin composition from the viewpoint of curability, or a tertiary agent which acts as a curing catalyst in the resin. It is preferable to introduce an amino group, and other coloring pigments, extenders, rust preventive pigments, dyes, pigment dispersing resins, pigment dispersing agents, leveling agents, defoaming agents, anti-sagging agents, solvents and the like may be added.

As the curing catalyst, a metal hydroxide, a metal organic acid salt,
At least one basic compound selected from quaternary ammonium bases, quaternary phosphonium bases, tertiary sulfonium bases, organic acid salts of these onium bases, alkali metal alkoxides and tertiary amino group-containing compounds or resins No. Examples of the metal hydroxide include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, and alkaline earth metal hydroxides such as calcium hydroxide, magnesium hydroxide and barium hydroxide. . In addition to the above, other metal hydroxides such as nickel hydroxide, copper hydroxide, molybdenum hydroxide, lead hydroxide, iron hydroxide, chromium hydroxide, manganese hydroxide, tin hydroxide, and cobalt hydroxide. Is mentioned.

As the above quaternary ammonium base, quaternary phosphonium base and tertiary sulfonium base, those represented by the following general formula can be used.

(In each formula, R _b , R _c , R _d and R _e are the same or different and are preferably hydrogen or an organic group having 1 to 14 carbon atoms, and R _b , R _c , R _d and R at least one of _e has 1 carbon atom
It is preferably from 14 to 14 organic groups. Further, these _Rb and _Rc , or _Rb , _Rc and _Rd may be taken together to form a heterocyclic ring together with the nitrogen atom, phosphorus atom or sulfur atom to which they are bonded. R _b , R _c , R _d and R _e preferably have an organic group having 1 to 14 carbon atoms, and R _b , R _c of the onium organic acid salt in the resin described above.
And the same thing can be used as exemplified organic group of 1 to 14 carbon atoms as R _d. Further, when R _b and R _c , or R _b , R _c and R _d together form a heterocyclic ring formed together with the nitrogen atom, phosphorus atom or sulfur atom to which they are bonded, Examples of the ions include the following.

The metal hydroxide and the organic acid salt of the onium base used as the curing catalyst in the method of the present invention are obtained by converting the hydroxide and the onium base to octenoic acid, naphthenic acid, abietic acid, acetic acid, formic acid, propionic acid. , Trimethylacetic acid, acrylic acid, methacrylic acid, lactic acid, hydroxyacetic acid, crotonic acid, chloroacetic acid, maleic acid monomethyl ester, fumaric acid monoethyl ester, itaconic acid monomethyl ester and the like. Examples of the alkali metal alkoxide include sodium ethoxide, sodium methoxide, potassium methoxide, potassium ethoxide, and the like.

Among the above, it is preferable to use a metal hydroxide and a metal organic acid salt because they form a film having excellent low-temperature curability and high-temperature water resistance. Among them, lead, manganese, and a metal organic acid selected from cobalt are preferable. Salts are particularly preferred.

The mixing ratio of the curing catalyst is suitably 20 parts by weight or less, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the resin solids.

Pigments that may be blended in the coating resin composition of the present invention,
Dyes, pigment-dispersed resins, various additives and solvents can be used without any particular limitation as long as they are usually used in the field of coatings. Among these, typical solvents include alcohols such as isopropanol, butanol, 2-ethylhexyl alcohol and benzyl alcohol, monoalkyl ethers of ethylene glycol such as octoxyethanol, monoalkyl ethers of propylene glycol, and diethylene glycol. Monoalkyl ethers, dipropylene glycol monoalkyl ethers, ethylene glycol dialkyl ethers, diethylene glycol and dipropylene glycol dialkyl ethers and aromatic, aliphatic, alicyclic hydrocarbons, ketones, dioxane, etc. And cyclic ethers.

The coating composition obtained by blending the curing catalyst and the like with the coating resin composition of the present invention can be applied as it is, or diluted with a solvent or water, and applied at a temperature of 50 ° C or higher, preferably 80 to 200 ° C, more preferably. Can be cured by heating at a temperature of 120 to 170 ° C. for preferably 5 minutes or more, more preferably about 10 to 60 minutes.

Effect of the Invention The curing mechanism of the resin composition for coating of the present invention is not clear, but a change in infrared absorption spectrum due to heating shows disappearance of an unsaturated group and a change in an ether bond, and generation of an isocyanate group is observed. In addition, the composition containing a curing catalyst cures at a relatively low temperature, and the weight loss due to heating is small.Therefore, the addition reaction of the hydroxyl group to the polymerizable unsaturated group, the ether exchange between the alkoxy group and the hydroxyl group of the alkoxyalkyl group. It can be assumed that the reaction and the dealcoholization condensation reaction between the alkoxyalkyl groups are occurring.

The coating resin composition of the present invention is a 3-alkoxyalkyl-3- (meth) acryloyl-ureide having two functional groups, an α, β-ethylenically unsaturated double bond and an alkoxyalkyl group bonded to an amide, in the resin. The ureide bond of this ureide group is stable, and it does not cause a dissociation reaction that generates free isocyanate even by heating during curing. There are almost no problems described above, and the corrosion resistance and the like are improved by improving the adhesion to the substrate by ureide bonding. Further, it is thought that the above reaction mechanism is involved, but the curability at low temperature is improved.

EXAMPLES Next, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples.

Hereinafter, “parts” and “%” mean “parts by weight” and “% by weight”, respectively.

Production of hydroxyl group-containing resin Production Example 1 760 parts of bisphenol A diglycidyl ether (epoxy equivalent: about 190, molecular weight: about 380) 760 parts, bisphenol A 228 parts and a flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser. 0.35 parts of dimethylbenzylamine was charged, and the epoxy equivalent was 4 at 120 ° C under nitrogen gas blowing.
The reaction was allowed to reach 90. Next, 303 parts of methyl isobutyl ketone, 168 parts of diethanolamine and 57.6 parts of N, N, N′-trihydroxy-1,2-diaminoethane were added, and the mixture was added at 80 ° C.
For 8 hours to obtain a hydroxyl group-containing resin solution (1). The resulting resin had an average of 4.1 primary hydroxyl groups / molecule and an average of 4.0 secondary hydroxyl groups / molecule.

Production Example 2 In a flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser, butyl glycidyl ether-modified bisphenol A diglycidyl ether (Ciba Geigy “XB
-4122 ", epoxy equivalent about 390), 470 parts, bisphenol A 270 parts and dimethylbenzylamine 0.3 part,
The reaction was carried out at 160 ° C. under nitrogen gas blowing until the epoxy group disappeared. Next, 603 parts of bisphenol A diglycidyl ether (epoxy equivalent: about 190, molecular weight: about 380) and 0.2 part of dimethylbenzylamine are added, and reacted at 130 ° C. until the epoxy equivalent becomes 650 or less, followed by 392 parts of methyl isobutyl ketone, diethanolamine 168 parts and N, N,
57.6 parts of N'-trihydroxy-1,2-diaminoethane was added and reacted at 80 ° C. for 8 hours to obtain a hydroxyl group-containing resin solution (2).

Production Example 3 In a flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser, 760 parts of bisphenol A diglycidyl ether (epoxy equivalent: about 190, molecular weight: about 380), 114 parts of bisphenol A and 0.3 part of dimethylbenzylamine The epoxy equivalent was 290 at 130 ° C under nitrogen gas injection.
The reaction was continued until Then ε-caprolactone 680
Part, tetrabutoxytitanate 0.2 part was added and reacted at 170 ° C., and a time-dependent sampling was performed to measure the amount of unreacted ε-caprolactone by infrared absorption spectrum measurement.
At 98% or more, 114 parts of bisphenol A and 0.04 part of dimethylbenzylamine were added and reacted at 150 ° C. until the epoxy equivalent became 830. After confirming the end point, 473 parts of methyl isobutyl ketone, 168 parts of diethanolamine and 168 parts of N, N, N ′
57.6 parts of trihydroxy-1,2-diaminoethane was added and reacted at 80 ° C. for 8 hours to obtain a hydroxyl group-containing resin solution (3).

Production Example 4 Diethylene glycol dimethyl ether was placed in a flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser.
500 parts were charged and at 110 ° C. under nitrogen gas blowing, 300 parts of 2-hydroxyethyl methacrylate, 157 parts of N, N-dimethylaminoethyl methacrylate, 300 parts of styrene, 243 parts of n-butyl acrylate and benzoyl peroxide 2
0 parts of the mixed solution was added dropwise over 3 hours. Then, the mixture was aged at 110 ° C. for 4 hours to obtain a hydroxyl group-containing resin solution (4).

Production Example 5 Diethylene glycol dimethyl ether was placed in a flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser.
500 parts were charged, and 300 parts of 2-hydroxyethyl methacrylate, 390 parts of styrene,
A mixed solution of 310 parts of butyl acrylate and 20 parts of benzoyl peroxide was added dropwise over 3 hours. Then 11
After aging at 0 ° C. for 4 hours, a hydroxyl group-containing resin solution (5) was obtained.

Production of Adduct a Production Example 6 A flask equipped with a stirrer, thermometer and reflux condenser was charged with 250 parts of diphenylmethane diisocyanate, 4.9 parts of 2,6-dichloroparabenzoquinone and 4.9 parts of dibutyltin dilaurate, and heated to 120 ° C. After the temperature, 235.5 parts of Nn-butoxymethylacrylamide were added dropwise while maintaining the temperature at 120 ° C., and when the NCO value reached 43, 44.1 parts of methyl isobutyl ketone was added to obtain an adduct a-1 solution.

Production Examples 7 to 12 The same procedures as in Production Example 6 were carried out except for using the formulations shown in Table 1 to obtain adduct a-2 to a-7 solutions.

Production of Adduct b Production Example 13 The procedure of Production Example 6 was repeated, except that the formulation was as shown in Table 1, to obtain an adduct b-1 solution. The adduct b-1 had 2.0 ureido groups of the formula (1) / molecule.

Production Example 14 A flask equipped with a stirrer, thermometer and reflux condenser was charged with 666 parts of isophorone diisocyanate, 11.4 parts of parabenzoquinone and 11.4 parts of dibutyltin dilaurate, and while maintaining the temperature at 120 ° C, N-n-butoxymethyl was added. Acrylamide (471 parts) was added dropwise, and when the NCO value reached 110, 134 parts of trimethylolpropane was added.
The reaction was performed at 20 ° C. When the NCO value became 0, 295 parts of methyl isobutyl ketone was added to obtain an adduct b-2 solution. The adduct b-2 has an average of ureido groups of the formula (1) of 3.0.
Particles / molecule.

Production of Resin Solution BC for Comparative Example Production Example 15 A flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser was charged with 500 parts of methyl ethyl ketone, and N-n was added at 80 ° C. under nitrogen gas blowing. -A mixed solution of 1000 parts of butoxymethylacrylamide and 20 parts of azobisdimethylvaleronitrile was added dropwise over 3 hours. Then 80 ° C
For 4 hours to obtain a resin solution BC-1.

Preparation of ac solution containing isocyanate group-containing adduct (for comparative example) Production Example 16 A flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 174 parts of tolylene diisocyanate, and heated to 70 ° C. 90 parts of ethyl ether was added dropwise while maintaining the temperature at 70 ° C., and when the NCO value reached 159, 29.3 parts of methyl isobutyl ketone was added to obtain an ad-ac-1 solution.

Production Example 17 A flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 174 parts of tolylene diisocyanate and 0.15 part of parabenzoquinone, heated to 70 ° C, and heated to 116 parts of 2-hydroxyethyl acrylate at 70 ° C. While dripping,
When the NCO value reached 145 after the reaction, 32.1 parts of methyl isobutyl ketone was added to obtain an ad-ac-2 solution.

Production Example 18 A flask equipped with a stirrer, thermometer and reflux condenser was charged with 174 parts of tolylene diisocyanate, 2.6 parts of parabenzoquinone and 2.6 parts of dibutyltin dilaurate,
The temperature was raised to 120 ° C., and 85 parts of methacrylamide was added dropwise while maintaining the temperature at 120 ° C., but the reaction was crystallized and the reaction could not proceed. Further, even if tetrahydrofuran was added to this reaction product, it could not be dissolved.

Ureido group-containing resin A solution of formula (I) and comparative resin
Production of AC Solution Production Example 19 A flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 1517 parts of the hydroxyl group-containing resin solution (1) and 347 parts of methyl ethyl ketone. 1350 parts of the solution was added dropwise over 90 minutes while maintaining the temperature at 70 ° C., the reaction was performed at 70 ° C., sampling was performed over time, and after confirming that the unreacted NCO had disappeared by infrared absorption spectrum measurement, 24 parts of ethylene glycol monobutyl ether were obtained. And add
A ureido group-containing resin A-1 solution was obtained. On average, the obtained resin has 3.75 ureido groups of the formula (I) in one molecule.
Each had 2.85 primary or secondary hydroxyl groups.

Production Examples 20 to 32 Except for using the formulations shown in Table 2, ureide group-containing resins A-2 to A-12 solutions and comparative resin AC-1 to AC-2 solutions were prepared in the same manner as in Production Example 19, respectively. Obtained.

Example 1 A clear coating was prepared by uniformly mixing 133 parts of the resin A-1 solution obtained in Production Example 19, 40 parts of methyl isobutyl ketone, 70 parts of propylene glycol monoisopropyl ether and 1 part of cobalt acetate (Table 3). ).

The paint was applied on a zinc phosphate-treated cold-rolled steel sheet by a bar coater so as to have a dry film thickness of 20 μm, and was baked and cured. The baking conditions were two types of 140 ° C. for 30 minutes and 160 ° C. for 30 minutes. Table 4 shows the coating film performance of the obtained baked coated plate.

Examples 2 to 12 A clear paint was prepared in the same manner as in Example 1 except that the composition was as shown in Table 3 to obtain a baked coated plate. Table 4 shows the coating film performance of the obtained baked coated plate.

Example 13 In a flask equipped with a stirrer, a thermometer and a reflux condenser, 1517 parts of the hydroxyl group-containing resin solution (1) obtained in Production Example 1, 1253 parts of the adduct b-1 solution obtained in Production Example 13, and ethylene glycol After charging 329 parts of dimethyl ether and mixing at 70 ° C. for 60 minutes, propylene glycol monomethyl ether
23 parts were added to obtain a mixed resin solution M-1. Using the obtained mixed resin solution M-1, except that the composition was as shown in Table 3, the same procedure as in Example 1 was performed to prepare a clear paint, and a baked coated plate was obtained.

Example 14 In a flask equipped with a stirrer, a thermometer and a reflux condenser, 1517 parts of the hydroxyl group-containing resin solution (1) obtained in Production Example 1, 1011 parts of the adduct b-2 solution obtained in Production Example 14, and ethylene glycol 162 parts of dimethyl ether were charged and uniformly mixed to obtain a mixed resin solution M-2. The obtained mixed resin solution M-
Example 2 was carried out in the same manner as in Example 1 except that the composition shown in Table 3 was used, and a clear paint was prepared to obtain a baked coated plate.

 Table 4 shows the test results of Examples 13 and 14.

Comparative Examples 1, 2 and 4 The procedure of Example 1 was repeated, except that the composition was as shown in Table 3, to prepare a clear paint, and a baked coated plate was obtained. Table 4 shows the coating performance of the baked coated plate.

Comparative Example 3 1517 parts of the hydroxyl-containing resin solution (1) and 966 parts of the resin solution BC-1 obtained in Production Example 15 were charged into a flask equipped with a stirrer, a thermometer and a reflux condenser, and mixed at 70 ° C. for 60 minutes. Thus, a mixed resin solution MC-1 was obtained. The obtained mixed resin solution MC-
Example 1 was carried out in the same manner as in Example 1 except that the composition shown in Table 3 was used to prepare a clear paint, and a baked coated plate was obtained.

 Table 4 shows the coating performance of the baked coated plate.

The tests in Table 4 were performed according to the following methods.

(* 1) Gel fraction: The free coating film was immersed in acetone at about 57 ° C. (under reflux) for 4 hours to perform extraction.

(* 2) Loss on heating: After coating, the solvent was removed under reduced pressure at 80 ° C. until the weight of the coating film before baking was constant. Thereafter, the coating was baked at a predetermined temperature for 30 minutes and determined by the following formula.

(* 3) Salt spray resistance: Cross-cut the coating film with a knife to reach the substrate, and perform salt spray test according to JIS Z2371. The maximum blister width or creep width of one side of the cross-cut becomes 3 mm. The time was recorded.

Claims (4)

(57) [Claims] (1) General formula Wherein R ¹ is a hydrogen atom or a methyl group, and R ² has 1 to 1 carbon atoms.
And R ³ represents an alkyl group having 1 to 10 carbon atoms. ] A resin composition for coating comprising a resin having an average of 0.6 or more per molecule of a 3-alkoxyalkyl-3- (meth) acryloyl-ureido group represented by the following formula and having a number average molecular weight of 800 to 50,000. 2. The resin according to claim 1, further comprising a primary or secondary resin, if necessary.
2. The coating resin composition according to claim 1, wherein the resin composition for coating has a primary hydroxyl group and a total of primary or secondary hydroxyl groups and a group represented by the general formula (I) is 2 or more per molecule on average. (3) a primary or secondary hydroxyl group having a molecular weight of 1.4
And containing a hydroxyl group-containing resin having a number average molecular weight of 600 to 50,000, and a general formula Wherein R ¹ is a hydrogen atom or a methyl group, and R ² has 1 to 1 carbon atoms.
And R ³ represents an alkyl group having 1 to 10 carbon atoms. ] A resin composition for coating comprising a resin having an average of at least one 3-alkoxyalkyl-3- (meth) acryloyl-ureido group represented by the following formula and a number average molecular weight of 400 to 30,000: . 4. The hydroxyl group-containing resin further contains a group represented by the general formula (I) if necessary, and the total of the primary or secondary hydroxyl group and the group represented by the general formula (I) is The resin composition for coating according to claim 3, wherein the average number is 2 or more per molecule.