JP2824095B2 - Coating method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for forming multilayer coatings, including cationic electrodeposition coatings and topcoats.

2. Description of the Related Art Conventionally, it has been already practiced to form a multilayer coating film by applying a cationic electrodeposition coating material, an intermediate coating material (coating with this coating material may be omitted) and a top coating material. The most commonly used cationic electrodeposition coatings are those based on a polyamine resin such as an amine-added epoxy resin and an aromatic polyisocyanate compound (curing agent) blocked with an alcohol or the like. Excellent evaluation of the anti-corrosion properties of the membrane. However, this cationic electrodeposition coating material has an essential problem in that the curing initiation temperature is high (170 ° C. or higher); and when a curing catalyst such as an organotin compound is used to lower the temperature, the tin compound is baked. May cause poisoning of furnace exhaust fuel catalysts; heating to high temperatures to cure coatings causes thermal decomposition of blocked polyisocyanate to form tarnish, soot,
In addition, yellowing, bleeding, curing inhibition, etc. are caused in the overcoat, and the weather resistance of the overcoat is significantly reduced, and the overcoat has serious defects such as easy whitening of the overcoat. Is desired. In particular, enormous costs and man-hours are required for maintenance and repair of equipment such as tar and soot. Further, the volume shrinkage due to the thermal decomposition or the dissociation of the block polyisocyanate has given the smoothness, gloss and adhesion of the finished coating film.

Means for Solving the Problems Accordingly, the present inventors have applied a specific cationic electrodeposition paint that does not require the use of a blocked polyisocyanate, an organotin compound, or the like, and applied an intermediate paint as necessary to the coated surface. After the application, by applying a top coat, the curability is excellent without lowering the anticorrosion property, and further, the above-mentioned various defects based on the use of the organotin compound or the blocked isocyanate compound can be eliminated, and furthermore, the volume can be reduced. The inventors have found that a multilayer coating film having excellent smoothness and adhesion can be formed because no distortion is caused by shrinkage, and the present invention has been completed.

Thus, according to one embodiment of the present invention, a resin (A) having a hydroxyl group and a cationic group; and an alicyclic skeleton and / or
Alternatively, a cationic electrodeposition paint containing, as a main component, an epoxy resin (B) having an average of two or more epoxy group-containing functional groups in which an epoxy group is bonded to an organic alicyclic skeleton per molecule, is applied. There is provided a method for forming a coating film, characterized by applying a top coat to a coated surface.

According to another aspect of the present invention, the above-described cationic electrodeposition paint is applied, and then the intermediate coating is applied to the coated surface, and then the top coating is applied to the intermediate coated surface. A coating film forming method is provided.

In the present invention, the electrodeposition coating film formed using the above cationic electrodeposition coating material is cured at a temperature of about 250 ° C. or less. And especially lead, zirconium, cobalt, aluminum,
When containing one or more compounds containing a metal such as manganese, copper, zinc, iron, chromium, and nickel as a catalyst,
It can be cured by heating at a low temperature of 70 ° C to about 160 ° C. In these curing, the epoxy group contained in the epoxy resin (B) is opened to react with a hydroxyl group (preferably a primary one) in the resin (A), and further, the epoxy group contained in the resin (B) is further cured. It is presumed that the epoxy groups react with each other to form an ether bond and crosslink and cure.

Therefore, the cationic electrodeposition paint used in the present invention can be cured at a low temperature of 160 ° C. or less without using a tin catalyst; further, since there is no need to use a blocked isocyanate compound or a derivative thereof, these can be used. The above-mentioned various defects due to cracking can be eliminated; good adhesion without volume shrinkage due to thermal decomposition; no need to bring in aromatic urethane bonds or aromatic urea bonds during cross-linking, impairing weather resistance It has various excellent advantages such as low corrosion resistance, excellent corrosion resistance and curability of the electrodeposition coating film, and good stability of the electrodeposition bath.

Therefore, according to the method of the present invention, if necessary, after applying an intermediate coating to the cationic electrodeposition coated surface, even if overcoated, yellowing, bleeding, occurrence of curing inhibition and the like are not observed. In addition, there is obtained an advantage that the weather resistance, smoothness, gloss and adhesion of the coating film are remarkably improved.

Hereinafter, the paint used in the present invention and the method of forming a coating film using the paint will be described in more detail.

Cationic electrodeposition coating composition: a resin (A) having a hydroxyl group and a cationic group; and an epoxy group-containing functional group formed by bonding an epoxy group to an alicyclic skeleton and / or a bridged alicyclic skeleton has an average of 2 per molecule. It is a cationic electrodeposition paint containing, as a main component, at least one epoxy resin (B).

Resin (A) containing a hydroxyl group and a cationic group (hereinafter, this may be referred to as “base resin (A)”)
Include any resin containing a hydroxyl group capable of reacting with the epoxy group of the component (B) and having a sufficient number of cationic groups to form a stable aqueous dispersion. The following are examples of the base resin (A).

(I) a reaction product obtained by reacting a polyepoxy resin with a cationizing agent; and (ii) a polycondensate of a polycarboxylic acid and a polyamine (see US Pat. No. 2,450,940), which is protonated with an acid. (Iii) Polyisocyanate and polyol adduct of mono- or polyamine and protonated with acid; (iv) Hydroxyl- and amino-group-containing copolymer of acrylic or vinyl monomer protonated with acid (V) A product obtained by protonating an adduct of a polycarboxylic acid resin and an alkyleneimine with an acid (see U.S. Pat. No. 3,403,088). (See JP-B-45-12395 and JP-B-45-12396) );etc.

Specific examples and production methods of these cationic resins are described in, for example, JP-B-45-12395 and JP-B-45-12396.
JP, JP-B-49-23087, U.S. Pat.No. 2,450,940
No. 3,403,088, U.S. Pat.
No. 3,891,529, U.S. Pat. No. 3,963,663, and the like, and the detailed description will be replaced with these citations here.

Particularly desirable as the base resin (A) in the cationic electrodeposition paint is a cationizing agent added to the epoxy group of the polyepoxide compound excellent in anticorrosion obtained from the polyphenol compound and epichlorohydrin, which is included in the above (i). It is a reaction product obtained by reacting.

The polyepoxide compound has a polyepoxy group Is a compound having two or more in one molecule, generally at least
200, preferably 400-4,000, more preferably 800-2,
Those having a number average molecular weight in the range of 000 are suitable. As such a polyepoxide compound, those known per se can be used, and examples thereof include a polyglycidyl ether of a polyphenol compound which can be produced by reacting a polyphenol compound with epichlorohydrin in the presence of an alkali. You. As the polyphenol compound that can be used here, for example,
Bis (4-hydroxyphenyl) -2,2-propane, 4,
4'-hydroxybenzophenone, bis (4-hydroxyphenyl) -1,1-ethane, bis- (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-tert-butyl-phenyl) ) -2,2-Propane, bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene, bis (2,4-dihydroxyphenyl) methane, tetra (4-hydroxyphenyl) -1,1,2 , 2−
Ethane, 4,4'-hydroxydiphenyl ether, 4,4 '
-Dihydroxydiphenyl sulfone, phenol novolak, cresol novolak and the like.

Among the above-mentioned polyepoxide compounds, those particularly suitable for the production of the base resin (A) have a number average molecular weight of at least about 380, more preferably about 800 to about 2,000, and an epoxy equivalent of 190 to 2,000, preferably Is a polyglycidyl ether of a polyphenol compound in the range of 400 to 1,000,
In particular, The polyepoxide compound represented by the following may be partially reacted with a polyol, polyether polyol, polyester polyol, polyamidoamine, polycarboxylic acid, polyisocyanate, and the like.
-4 Caprolactone, an acrylic monomer or the like may be graft-polymerized.

On the other hand, examples of the cationizing agent for introducing a cationic group into the polyepoxide compound include aliphatic or alicyclic or aromatic-aliphatic primary or secondary amines, tertiary amine salts, and secondary amines. And tertiary phosphine salts. These react with epoxy groups to form cationic groups. Further, a tertiary amino alcohol obtained by the reaction of a diisocyanate with a tertiary amino alcohol
The quaternary aminomonoisocyanate may be reacted with a hydroxyl group of the epoxy resin to form a cationic group.

Examples of the amine compound in the cationizing agent include, for example, the following.

(1) Methylamine, ethylamine, n- or iso-
Propylamine, monoethanolamine, n- or iso
Primary amines such as -propanolamine; (2) secondary amines such as diethylamine, diethanolamine di-n- or iso-propanolamine, N-methylethanolamine, N-ethylethanolamine; (3) ethylenediamine, diethylenetriamine, Polyamines such as hydroxyethylaminoethylamine, ethylaminoethylamine, methylaminopropylamine, dimethylaminoethylamine and dimethylaminopropylamine.

Of these, alkanolamines having a hydroxyl group are preferred. Alternatively, the primary amino group may be reacted with a ketone in advance and blocked, and then reacted with the epoxy group with the remaining active hydrogen.

Further, other than the above-mentioned amine compounds, basic compounds such as ammonia, hydroxylamine, hydrazine, hydroxyethylhydrazine and N-hydroxyethylimidazoline compounds can be used in the same manner. The basic group formed using these compounds can be protonated with an acid, particularly preferably a water-soluble organic carboxylic acid such as formic acid, acetic acid, glycolic acid or sulfuric acid, to form a cationic group.

In addition, triethylamine, triethanolamine,
Tertiary amines such as N, N-dimethylethanolamine, N-methyldiethanolamine, N, N-diethylethanolamine, N-ethyldiethanolamine and the like can also be used. These are previously protonated with an acid and reacted with an epoxy group. It can be a quaternary salt.

In addition to amino compounds, diethylene sulfide,
A tertiary sulfonium salt may be obtained by reacting a salt of a sulfide such as diphenyl sulfide, tetramethylene sulfide or thiodiethanol with a boric acid, a carbonic acid or an organic monocarboxylic acid with an epoxy group.

Further, a quaternary phosphonium salt may be obtained by reacting a salt of a phosphine such as triethylphosphine, phenyldimethylphosphine, diphenylmethylphosphine or triphenylphosphine with an acid as described above with an epoxy group. .

As the hydroxyl group of the base resin (A) used in the cationic electrodeposition coating, for example, alkanolamine in the above-mentioned cationizing agent, a caprolactone ring-opened product which may be introduced into an epoxide compound, and a primary group which can be introduced from a polyol, etc. A hydroxyl group; a secondary hydroxyl group in an epoxy resin; and the like. Among these, the primary hydroxyl group introduced by the alkanolamine is preferred because of its excellent crosslinking curing reactivity with the epoxy resin (B). Such alkanolamines are preferably those exemplified above for the cationizing agent.

The content of the hydroxyl group in the base resin (A) is from 20 to 5,000, particularly preferably from 100 to 1,000, in terms of the hydroxyl equivalent in view of the reactivity of crosslinking and curing with the epoxy group contained in the epoxy resin (B).
The primary hydroxyl equivalent is particularly preferably 200 to 1,0.
Desirably within the range of 00. Further, the content of the cationic group is preferably at least the minimum necessary for stably dispersing the base resin (A), and is generally 3 to 200 in terms of KOH (mg / g solid content) (amine value). Preferably it is in the range of 10-80. However, even when the content of the cationic group is 3 or less, it is also possible to use the composition after dispersing it in an aqueous solution using a surfactant or the like.
The pH of the aqueous dispersion composition is usually 4 to 9, more preferably 6 to 9.
It is desirable to adjust the cationic group so as to be 7.

The base resin (A) has a hydroxyl group and a cationic group and desirably does not contain a free epoxy group in principle.

Next, the epoxy resin (B) as a curing agent used by mixing with the base resin (A) will be described.

The epoxy resin (B) (hereinafter sometimes referred to as “curing resin (B)”) is used to form a crosslinked cured coating film with the base resin (A) mainly by an etherification reaction as described above. A curing agent having an average of two or more, preferably three or more, specific “epoxy group-containing functional groups” per molecule.

That is, the epoxy group-containing functional group in the curing resin (B) comprises an alicyclic skeleton and / or a bridged alicyclic skeleton and an epoxy group, and the alicyclic skeleton has 4 to 10 members, preferably It contains a 5- to 6-membered saturated carbocyclic ring or a condensed ring obtained by condensing two or more such rings, and the bridged alicyclic skeleton has
A linear or branched _C1-6 (preferably C1) between two carbon atoms constituting the cyclic or polycyclic ring.
_1-4) alkylene group [e.g. _{-CH 2 -, - CH 2 CH} 2 -,
_{-CH (CH 3) -, -} CH (CH 3) CH 2 -, - C (CH 3) 2 -,
—CH (C ₂ H ₅ ) CH ₂ —, etc.] (endmethylene, endethylene, etc.).

On the other hand, epoxy group Is that one of the carbon atoms in the epoxy group is directly bonded to a ring carbon atom in the alicyclic skeleton or bridged alicyclic skeleton [see, for example, the following formulas (I) and (II)]. Alternatively, two carbon atoms of the epoxy group and two adjacent carbon atoms constituting a ring in the alicyclic skeleton or bridged alicyclic skeleton are common [for example, the following formula (III) , (IV)] is important.

Specific examples of such epoxy group-containing functional groups include:
Examples represented by the following formulas (I) to (IV) are given.

Wherein R ₁ , R ₂ , R ₃ , R ₅ , R ₆ , R ₇ , R ₁₀ and R ₁₁ each represent H, CH ₃ or C ₂ H ₅ , and R ₄ , R ₈ and R ₉ are each represents a H or CH _3.

The epoxy resin (B) used for the cationic electrodeposition paint is
The epoxy group-containing functional group selected from the above formulas (I) to (IV) can have an average of at least 2, preferably 2 or more, more preferably 4 or more per molecule. For example, the formula (I) or ( It may have at least one epoxy group-containing functional group represented by the formula (II), or
It may have at least one epoxy group-containing functional group represented by I) or (IV). Furthermore, the epoxy resin (B) comprises at least one of the epoxy group-containing functional groups represented by the formula (I) or (II) and at least one of the epoxy group-containing functional groups represented by the formula (III) or (IV). One and the other can be in the same molecule or in different molecules.

Among the above, the epoxy group-containing groups represented by the formulas (I) and (III) are preferable, and particularly, the following formula (V) And an epoxy group-containing functional group represented by the following formula (VI) The epoxy group-containing functional group represented by is preferred.

Further, the epoxy equivalent and molecular weight of the epoxy resin (B) are not strictly limited, and can be changed according to the production method, the use of the final resin composition, and the like.
Generally speaking, the epoxy equivalent can usually be in the range of 100 to 2,000, preferably 1500 to 500, more preferably 150 to 250, and the number average molecular weight is usually 400 to 1
00,000, preferably 700-50,000, more preferably 700
Suitably it is in the range of ~ 30,000.

Such epoxy resins having two or more epoxy group-containing functional groups in one molecule [curing resin (B)] are described in, for example, JP-B-56-8016, JP-A-57-57365,
It is described in documents such as JP-A-60-166675, JP-A-63-221121, and JP-A-63-234028, and those known per se can be used.

Alternatively, the epoxy resin (B) having an epoxy group-containing functional group can be obtained by a method known per se,
The main production methods are listed below, but are not limited thereto.

First production method: a part of the alicyclic compound having two or more carbon-carbon double bonds in a molecule is partially epoxidized, and the epoxy group is subjected to ring-opening polymerization. A method of epoxidizing the remaining double bond.

Second production method: a method in which an alicyclic compound having two or more epoxy groups in the same molecule is subjected to ring-opening polymerization based on the epoxy group to such an extent that all of the epoxy groups are not erased.

Third production method: a method of polymerizing a compound having an epoxy group-containing functional group and a polymerizable unsaturated bond in the same molecule.

Hereinafter, these manufacturing methods will be described more specifically.

First production method: A part of the double bond contained in an alicyclic compound having two or more carbon-carbon double bonds in one molecule (hereinafter abbreviated as “alicyclic compound (A)”) After epoxidation (partially epoxidized product) and then ring opening polymerization of the epoxy group to obtain a ring-opened polymer of the partially epoxidized product, part or all of the double bonds remaining in the polymer are epoxidized. Thus, a curing resin (B) is obtained.

The alicyclic compound (A) has the alicyclic ring or bridged alicyclic ring structure described above for the alicyclic skeleton or bridged alicyclic skeleton as a basic skeleton, and further has a double bond to form an adjacent ring. A compound which is present between two carbon atoms or contains at least two or more double bonds based on other carbon atoms directly bonded to carbon atoms constituting the ring structure.

The alicyclic compound (A) can also be obtained, for example, by heating a conjugated diene compound according to a known method. As the conjugated diene compound, an aliphatic or alicyclic compound having 4 to 30 carbon atoms having one or more pairs, preferably 1 to 5 pairs of conjugated double bonds in one molecule is suitable. Include butadiene, isoprene, pyrylene, 1,3-hexadiene, 2,4-hexadiene, 2,4-heptadiene, 2-
Methyl-6-methylene-2,7-octadiene, 2,6-dimethyl-1,5,7-octatriene, cyclopentadiene,
Cyclohexadiene, 4-ethyl-2-methylcyclopentadiene, 3-isopropyl-1-methylcyclopentadiene, 5-isopropylcyclopentadiene, 1,2,
3,4-tetraphenylcyclopentadiene, 1,2,4-triphenylcyclopentadiene, 1,4-diphenylcyclopentadiene, 1,3-octachloropentadiene, hexachlorocyclopentadiene, 5,5-diethoxy-1 , 2,
3,4-tetrachlorocyclopentadiene, 1,2,3,4,5-pentachlorocyclopentadiene, 1,2,3,4-tetrachlorocyclopentadiene, 1,3-cycloheptadiene, 1,3
-Cyclooctadiene, 1,3,5-cyclooctatriene, 1,3,6-cyclooctatriene, cyclooctatetraene, chlorocyclooctatetraene, bromocyclooctatetraene, 5-cyclohexylidenecyclopentadiene, etc. These can be used alone or in combination of two or more.

When the conjugated diene compound is reacted under heating using a Ziegler catalyst as required, an alicyclic compound (A) is obtained. This heating reaction can be performed by a method known per se, for example, a method disclosed in JP-A-49-102643. Representative examples of the alicyclic product (A) thus obtained are as follows.

Among the conjugated diene compounds, cyclopentadiene,
Compounds having an alicyclic structure such as cyclohexadiene and 4-ethyl-2-methylcyclopentadiene, and silvestrene, 2,8 (9) -p-menthadiene, pyronene,
1,3-Dimethyl-1-ethyl-3,5-cyclohexadiene, terpinene, ferrandrene, dipentene, isolimonene, limonene and the like already have the structure of the alicyclic compound (A), and are subjected to the above-mentioned thermal reaction. It can be used as it is without.

First, a part of the carbon-carbon double bond contained in the alicyclic compound (A) is modified into an epoxy group with a peroxide or the like (partial epoxidation). The partially epoxidized product is obtained by partially modifying a plurality of double bonds contained in the alicyclic compound (A) to an epoxy group, and specific examples thereof are as follows.

Naturally obtained epoxycarene and the like can also be used as a partially epoxidized product.

The partially epoxidized compound has at least one group and at least one carbon-carbon double bond in one molecule, and the double bond exists between two adjacent carbon atoms constituting the ring, or It is necessary that a double bond based on another carbon atom is bonded to a carbon atom of the ring.

Next, the polymer of the alicyclic compound (A) is obtained by ring-opening polymerization based on the epoxy group in the partially epoxidized product. An initiator is preferably used for the ring-opening polymerization, and a residue Y of the initiator component may be bonded to a terminal of the curing resin (B) as a final product. Here, Y is an organic compound residue having active hydrogen, and examples of the organic compound having active hydrogen as a precursor thereof include alcohols, phenols, carboxylic acids, amines, and thiols. . Of these, as alcohols,
It may be any of a monohydric alcohol and a polyhydric alcohol having 2 or more valencies, and specifically, for example, a resin group monohydric alcohol such as methanol, ethanol, propanol, butanol, pentanol, hexanol and octanol;
Aromatic monohydric alcohols such as benzyl alcohol; ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, pentanediol, 1,6 −
Hexanediol, neopentyl glycol, neopentyl glycol oxypivalate, cyclohexane dimethanol, glycerin, diglycerin, polyglycerin, polyhydric alcohols such as trimethylolpropane, trimethylolethane, pentaerythritol and dipentaerythritol are exemplified. You.

Examples of phenols include phenol, cresol, catechol, progalol, hydroquinone, hydroquinone monomethyl ether, bisphenol A,
Bisphenol F, 4,4'-dihydroxybenzophenone, bisphenol S, phenolic resin, cresol novolak resin and the like.

As carboxylic acids, formic acid, acetic acid, propionic acid,
Butyric acid, fatty acids of animal and vegetable oils; fumaric acid, maleic acid, adipic acid, dodecane diacid, trimellitic acid, pyromellitic acid, polyacrylic acid, phthalic acid, isophthalic acid, terephthalic acid, etc .; Compounds having both a hydroxyl group and a carboxylic acid such as citric acid and oxycaproic acid can also be used.

Further, as other compounds having active hydrogen, tetramethyl silicate, tetraethyl silicate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, a mixture of alkoxysilane and water such as phenyltrimethoxysilane or a silanol compound thereof , Polyvinyl alcohol, polyvinyl acetate partial hydrolyzate, starch, cellulose, cellulose acetate, cellulose acetate butyrate, hydroxyethyl cellulose, acrylic polyol resin, styrene-allyl alcohol copolymer resin, styrene-maleic acid copolymer resin, alkyd resin, Polyester polyol resins, polycaprolactone polyol resins and the like can also be used. Further, it may have an unsaturated double bond together with active hydrogen, and the unsaturated double bond may be epoxidized. Further, the catalyst and the initiator may be the same, such as an alkoxy metal compound.

Usually, the above-mentioned organic compound having active hydrogen is used as an initiator, and the above-mentioned partially epoxidized product, for example, 4-vinylcyclohexene-1-oxide, 4-vinylcyclo [2,2,1] 3
-Methyl-4 (or 5) -t-propenyl-1-cyclohexene oxide, 2,4- or 1,4-dimethyl-4ethenyl-1-cyclohexene oxide, 4-vinylcyclo [2,2,1] heptene-1 And ring-opening polymerization using one or more of -oxide (vinyl norbornene oxide), 2-methyl-4-isopropanyl-cyclohexene oxide or the like. At this time, ring-opening copolymerization can be carried out in the presence of another epoxy compound which does not belong to the above partially epoxidized product. Other epoxy compounds that can be copolymerized may be any compounds having an epoxy group, and preferred examples thereof include oxides of unsaturated compounds such as ethylene oxide, propylene oxide, butylene oxide, and styrene oxide. Glycidyl ether compounds such as allyl glycidyl ether, 2-ethylhexyl glycidyl ether, methyl glycidyl ether, butyl glycidyl ether, and phenyl glycidyl ether; glycidyl ester compounds of unsaturated organic carboxylic acids such as acrylic acid and methacrylic acid; -Alicyclic oxirane group-containing vinyl monomers such as epoxycyclohexylmethyl (meth) acrylate;

The above-mentioned ring-opening polymer is prepared by ring-opening polymerization (ether bond) of an epoxy group contained in a partially epoxidized product alone or in combination with another epoxy compound as required.
To be obtained. The composition ratio of other epoxy compounds in the ring-opened polymer can be arbitrarily selected depending on the purpose. Specifically, the structural formulas (I) to (IV) per molecule of the obtained ring-opened copolymer One or more of the above two or more, preferably three or more on average,
More preferably, it is desirable to select within the range of four or more.

The number average molecular weight of the (co) polymer obtained in this way is generally from 400 to 100,000, in particular from 700 to 50,000, and even
Preferably it is in the range of ~ 30,000.

In general, the ring-opening polymerization reaction is preferably performed in the presence of a catalyst. Examples of usable catalysts include amines such as methylamine, ethylamine, propylamine and piperazine; organic bases such as pyridines and imidazoles. Organic acetic acids such as formic acid, acetic acid and propionic acid; sulfuric acid;
Inorganic acids such as hydrochloric acid; alkali metal alcoholates such as sodium methylate; alkalis such as KHO and KaOH; BF ₃ , ZnCl
_2. Lewis acids such as AlCl ₃ and SnCl ₄ or complexes thereof; and organometallic compounds such as triethylaluminum, aluminum acetylacetonate, titanium acetylacetonate, diethylzinc and the like.

These catalysts can be used generally in the range of 0.001 to 10% by weight, preferably 0.1 to 5% by weight, based on the reactants. The ring-opening polymerization reaction temperature is generally about -70 to about 200.
° C, preferably in the range of about -30 ° C to about 100 ° C. The reaction can be performed using a solvent, and it is preferable to use a normal organic solvent having no active hydrogen as the solvent.

The ring-opened polymer has a double bond based on the alicyclic compound (A), and an epoxy resin (B) can be obtained by epoxidizing all or a part of the double bond. Epoxidation of the double bond can be carried out using an epoxidizing agent such as peracids and hydroperoxides. The presence or absence of a solvent and the reaction temperature at the time of the epoxidation reaction can be appropriately adjusted according to the equipment to be used and the physical properties of the raw materials.
Depending on the conditions of the epoxidation reaction, a side reaction may occur simultaneously with the epoxidation of the double bond in the raw material ring-opening polymer, and the modified substituent may be contained in the skeleton of the epoxy resin (B). . As the modified substituent, for example, when peracetic acid is used as the epoxidizing agent, a substituent having the following structure can be mentioned, which is considered to be due to the reaction between the generated epoxy group and acetic acid produced as a by-product. .

The ratio of these modified substituents is determined by the type of the epoxidizing agent, the molar ratio of the epoxidizing agent to the unsaturated group, and the reaction conditions.

The epoxy equivalent of the epoxy resin (B) thus obtained is generally from 100 to 2,000, in particular from 150 to 500, more preferably from 150 to 500.
It is preferably in the range of ~ 250.

Commercial products can also be used as such an epoxy resin (B). For example, EHPE-3150, EHPE-3100, EHPE-11
50 [trade name of Daicel Chemical Industries, Ltd.] and the like.
This is an epoxy resin having a cyclohexane skeleton using 4-vinylcyclohexene-1-oxide and having the following structural formula.

In the formula, n is 2 or more, preferably 3 or more, more preferably 4 or more.

Second production method: For example, it can be obtained by epoxidizing at least two of the double bonds contained in the alicyclic compound (A), and then subjecting the alicyclic compound to ring-opening polymerization so that the epoxy group remains.

As the epoxidized compound having an average of two or more epoxy groups per one molecule, the following monocyclic or condensed cyclic compound is representatively shown.

Specifically, at least one of the above epoxidized products is replaced with the first epoxidized product.
In the same manner as described in the production method of the above, the ring-opening polymerization reaction is carried out using an initiator and a catalyst as necessary, and the reaction is stopped at a predetermined reaction point where the epoxy group remains, thereby obtaining an epoxy resin (B Get) Any means such as dilution with a solvent and cooling can be used to stop the reaction. In this production method, the other epoxy compound may be copolymerized in the same manner as in the first production method.

The curing resin (B) obtained in this manner is represented by the formula (I)
Or an epoxy having at least one epoxy group-containing functional group represented by formula (II) and at least one epoxy group-containing functional group represented by formula (III) or (IV) in the same molecule or a different molecule It can also be a resin.

The number average molecular weight of the ring-opened polymer [curing resin (B)] thus obtained is generally from 400 to 100,000, especially 70.
It is preferably in the range of 0 to 50,000, and the epoxy equivalent is generally 100 to 2,000, especially 150 to 500, and even 15
Conveniently it is in the range of 0-250.

Third Production Method: Examples of a compound having at least one epoxy group-containing functional group and at least one polymerizable unsaturated bond in the same molecule (hereinafter sometimes abbreviated as “polymerizable epoxy monomer”) include, for example, The following general formulas are shown.

In the above general formula, R ₁₁ represents a hydrogen atom or a methyl group, R ₁₂ represents a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, and R ₁₃ represents a divalent carbon group having 1 to 10 carbon atoms. Represents a hydrogen group.

In the polymerizable epoxy monomer, examples of the divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms represented Te R ₁₂ Niyotsu, linear or branched alkylene group such as methylene, ethylene, propylene, Examples include tetramethylene, ethylethylene, pentimethylene, and hexamethylene groups. The divalent hydrocarbon group having 1 to 10 carbon atoms represented Te R ₁₂ Niyotsu, such as methylene,
Ethylene, propylene, tetramethylene, ethylethylene, pentamethylene, hexamethylene, polymethylene,
Phenylene, And the like.

Specific examples of the polymerizable epoxy monomers represented by the general formulas (1) to (3) include 3,4-epoxycyclohexylmethyl acrylate and 3,4-epoxycyclohexylmethyl methacrylate. As these commercially available products, for example, METHB, AETB manufactured by Daicel Chemical Industries, Ltd.
(All are trade names) and the like, each of which has an epoxy group-containing functional group represented by the formula (I) or (II). Further, 4-vinylcyclohexene oxide can be used as the polymerizable epoxy monomer.

One or two selected from polymerizable epoxy monomers
The epoxy resin (B) can be produced by polymerizing more than one kind, and at that time, another polymerizable unsaturated monomer can be copolymerized.

The other polymerizable unsaturated monomer can be selected widely according to the performance desired for the obtained (co) polymer. Representative examples thereof are as follows.

(A) Esters of acrylic acid or methacrylic acid: for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate, methyl methacrylate, methacrylic C1-C18 alkyl esters of acrylic acid or methacrylic acid, such as ethyl acrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, and lauryl methacrylate; methoxybutyl acrylate, methacrylic acid Methoxybutyl, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxybutyl acrylate, ethoxybutyl methacrylate, etc. C2-8 alkenyl esters of acrylic acid or methacrylic acid such as allyl acrylate and allyl methacrylate; and C2 of acrylic acid or methacrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate And hydroxyalkyl esters of 8 to 8; alkenyloxyalkyl esters of acrylic acid or methacrylic acid having 3 to 18 carbon atoms, such as allyloxyethyl acrylate and alkyloxy methacrylate.

(B) vinyl aromatic compounds; for example, styrene, α-
Methylstyrene, vinyltoluene, p-chlorostyrene.

(C) Polyolefin-based compounds: for example, butadiene, isoprene and chloroprene.

(D) Others: acrylonitrile, methacrylonitrile, methyl isopropenyl ketone, vinyl acetate veoba monomer (Ciel Chemical), vinyl propionate, vinyl pivalate, vinyl compound having a polycaprolactone chain (for example, FM-3X monomer: Daicel Chemical industry trade name).

The composition ratio of the polymerizable epoxy monomer and the other polymerizable unsaturated monomer can be arbitrarily selected depending on the purpose, and is preferably determined per molecule of the epoxy resin (B) obtained by the copolymerization reaction. An epoxy group-containing functional group can be selected in a range containing at least two, preferably three or more on average, and more preferably four or more on average, but is used as a functional group that imparts sufficient curability. For this purpose, it is particularly preferable that the content of the polymerizable epoxy monomer in the solid content of the epoxy resin (B) is in the range of 5 to 100% by weight, more preferably 20 to 100% by weight.

The epoxy resin (B) obtained by the third manufacturing method can be manufactured by using the same method and conditions as those for a polymerization reaction based on a polymerizable unsaturated bond of a general acrylic resin or vinyl resin. . As an example of such a polymerization reaction, a method of dissolving or dispersing each monomer component in an organic solvent and heating with stirring at a temperature of about 60 to 180 ° C. in the presence of a radical polymerization initiator can be shown. . The reaction time can be generally about 1 to 10 hours. Further, as the organic solvent, an alcohol solvent, an ether solvent, an ester solvent, a hydrocarbon solvent and the like can be used. When a hydrocarbon solvent is used, it is preferable to use another solvent in combination from the viewpoint of solubility. Further, any of those generally used as a radical initiator can be used. Specific examples thereof include benzoyl peroxide, t
Peroxides such as -butylperoxy-2-ethylhexanoate; and azo compounds such as azoisobutylnitrile and azobisdimethylvaleronitrile.

The epoxy resin (B) of the third production example preferably has a number average molecular weight generally in the range of about 3,000 to about 100,000, more preferably in the range of 4,000 to 10,000.

Among the above curing resins (B), epoxy groups per molecule are suitable for use in applications requiring high performance such as cationic electrodeposition coatings used for automobile bodies. It has three or more contained functional groups on average, more preferably four or more on average, and most preferably five or more on average, and has an epoxy equivalent of preferably 100 to 2,000, more preferably 150 to 2,000. ~ 500, especially 150 ~ 250
And the number average molecular weight is preferably 400
To 100,000, more preferably 700 to 50,000, particularly preferably 700 to 30,000.

The amount of the curing resin (B) used depends on the base resin (A) used.
Depending on the type, the obtained coating film can be appropriately changed within a range from a minimum amount required for heat curing to a maximum amount that does not impair the stability of the cationic electrodeposition coating composition, but generally for curing. The weight ratio of the solid content of the resin (B) to the base resin (A) is 0.2 to 1.0, particularly 0.25 to 0.85, and more desirably.
It is preferred that the selection be made in the range of 0.25 to 0.65.

The cationic electrodeposition paint used in the present invention may contain a part of the curing resin (B) previously added to the base resin (A).

To prepare the cationic electrodeposition paint used in the present invention, for example, after mixing the base resin (A) and the curing resin (B), the mixture is stably dispersed in water, and then, if necessary, carbon black, titanium Color pigments such as white, lead white, lead oxide and red iron oxide; extender pigments such as clay and talc; strontium chromate, lead chromate, basic lead chromate, leadtan, lead silicate and basic lead silicate Anticorrosive pigments such as lead phosphate, basic phosphate phosphate, lead tripolyphosphate, lead silicosilicate, graphite, cyanamide lead, calcium lead oxide, lead suboxide, lead sulfate, basic lead sulfate; or other additives It is performed by kneading the agent. Other additives that may be incorporated include, for example, a small amount of a nonionic surfactant as a dispersant or an anti-cissing agent for a coated surface; a curing accelerator, and the like.

In particular, in order to sufficiently cure the electrodeposition coating film at a low temperature of 160 ° C. or less, a lead compound, a zirconium compound, a cobalt compound, an aluminum compound, a manganese compound, a copper compound, a zinc compound, an iron compound, a chromium compound, It is effective to add one or more metal compounds selected from nickel compounds and the like as a catalyst. Specific examples of these metal compounds include, for example, zirconium acetylacetonate, cobalt acetylacetonate,
Chelating compounds such as aluminum acetylacetonate and manganese acetylacetonate; chelation reaction products of a compound having a β-hydroxyamino structure with lead (II) oxide; lead 2-ethylhexanoate, secanoic lead, naftix lead, octix lead , Lead benzoate, lead acetate,
Examples include carboxylate such as lead lactate, lead formate, lead glycolate, and octixus zirconium.

The metal compound generally has a metal content based on the total solid weight of the base resin (A) and the curing resin (B).
It can be used in an amount of up to 10% by weight, preferably up to 5% by weight.

The film thickness of the coating film obtained by electrodepositing the thus prepared cationic electrodeposition coating material on a suitable substrate is not strictly limited, but is generally from 3 to 3 based on the cured coating film.
A range of 200μ is suitable, and the coating is, for example, 70-2.
The composition can be cured by heating at a temperature of 50C, preferably between 120C and 160C.

The method for forming an electrodeposition coating film on a substrate using the above-mentioned cationic electrodeposition coating material is not particularly limited, and it can be carried out using ordinary cationic electrodeposition coating conditions. For example, the base resin (A) and the curing epoxy resin (B) are dispersed in water as described above, and then a pigment, a curing catalyst, and other additives are blended as necessary, and the bath concentration (solids concentration) A cationic electrodeposition bath is prepared with 5-40% by weight, preferably 10-25% by weight, and a bath pH of 5-8, preferably 5.5-7. Then, using this electrodeposition bath, for example, 5 cm x 1
A carbon plate with a size of 5 cm x 1 cm is used as the anode, and, for example,
When a zinc phosphate treated plate having a size of 5 cm × 15 cm × 0.7 mm is used as a cathode, electrodeposition can be performed under the following conditions.

Bath temperature: 20 to 35 ° C., preferably 25 to 30 ° C., direct current current density: 0.005~2A / cm ^2, preferably 0.01~1A / cm ² Voltage: 10～500V, preferably 100~300V energization time: After electrodeposition coating for 0.5 to 5 minutes, preferably 2 to 3 minutes, after the object to be coated is taken out of the electrodeposition bath and washed with water, water contained in the electrodeposition coating film can be removed by a drying means such as hot air. .

The electrodeposited coating film formed by using the cationic electrodeposition paint in this manner can be cured by heating as described above.

In the present invention, it is acceptable to directly apply a top coat to the cationic electrodeposition surface, but if an excellent finished appearance is required, apply an intermediate coat to the electrodeposition surface before applying the top coat. Painting is preferred.

As the intermediate coating, a known intermediate coating having excellent adhesion, smoothness, sharpness, overbake resistance, weather resistance and the like can be used. Specifically, oil length
An organic solution type thermosetting intermediate coating material containing 30% or less of a short oil or ultrashort oil alkyd resin or an oil-free polyester resin and an amino resin as a main component of a vehicle is exemplified. These alkyd resins and polyester resins are
It is preferable that the hydroxyl value is 60 to 140 and the acid value is 5 to 20, and that an unsaturated oil (or unsaturated fatty acid) is used as the modified oil.
5) Etherified mesamine resin, urea resin, benzoguanamine resin and the like are suitable. These compounding ratios should be 65 to 85% by weight of alkyd resin and / or oil-free polyester resin, especially 70 to 80% by weight, and 35 to 15% by weight of amino resin, especially 30 to 20% by weight based on the solid content. Is preferred. Further, the amino resin can be replaced with a polyisocyanate compound or a blocked polyisocyanate compound. The form of the intermediate coating is
The organic solution type is most preferable, but a non-aqueous dispersion type, a high solids type, an aqueous solution type, an aqueous dispersion type or the like using the above-mentioned vehicle component may be used. In the present invention, the hardness (pencil hardness) of the intermediate coating film is preferably in the range of 3B to 2H. Further, extender pigments, coloring pigments, and other paint additives can be added to the intermediate coating paint as needed.

The method of applying the intermediate coating is not particularly limited,
Methods known per se can be employed, such as spray painting,
Brush coating, dip coating, electrostatic coating and the like, and the coating film thickness is generally 10 ~ 50μ, especially 20 ~
A range of 30μ is preferred. The method of curing the intermediate coating composition varies depending on the composition, but for example, it is preferable to cure by heating to a temperature of about 80 to about 160 ° C.

The topcoat paint applied to the surface of the cationic electrodeposition coating film or the intermediate coating film according to the present invention is a paint that imparts aesthetics to the uncoated material, and specifically has a finished appearance (brightness, smoothness, etc.). , Gloss), weather resistance (gloss retention, color retention, chalk resistance, etc.), chemical resistance, water resistance, moisture resistance, curability, etc. Paint can be used. Specifically, amino-acrylic resin, amino-alkyd resin, amino-polyester resin,
And the like as a vehicle main component. The form of these paints is not particularly limited, and examples thereof include an organic solution type, a non-aqueous dispersion type, an aqueous (dispersion) liquid type, a powder type, and a high solid type.

Curing of the coating film can be carried out by drying at room temperature, drying by heating, irradiation with active energy rays such as electron beams and ultraviolet rays. In the present invention, it is desirable that the formed coating film of these top coats has a pencil hardness of 2B or more.

The topcoat paint used in the present invention is a metallic paint or a solid color finish paint in which a metallic pigment and / or a coloring pigment is blended with the paint containing the above-mentioned vehicle main component, and a clear paint (color clear paint) containing these pigments at all or little. Also included). Then, as a method of forming a top coat using these paints, for example, a metallic paint, a metallic paint containing a coloring pigment if necessary, or a solid color paint containing a coloring pigment is applied, and heated. Cures (metallic or solid color finish by one coat and one bake method).

After applying a metallic paint or a solid color paint and heat-curing, a clear paint is further applied and heat-cured again (metallic or solid color finish by two-coat two-bake method).

After applying a metallic paint or a solid color paint, and then applying a clear paint, the two paint films are simultaneously cured by heating (metallic or solid color finish by a two-coat one-bake method).

It is preferable to apply these top coatings by spray coating, electrostatic coating or the like. In addition, the coating film thickness is 25 to 40 μ in the above, based on the dry coating film, and in the above, 10 to 30 μ for the metallic paint and the solid color paint,
The clear paint preferably has a thickness of 25 to 50 µ. The heating conditions can be arbitrarily selected depending on the vehicle components and the material of the object to be coated, etc., but are generally about 60 to about 140 ° C., particularly 80 to 140 ° C.
Preferably 10 to 40 minutes.

Next, the present invention will be described more specifically with reference to examples. In the present invention, “parts” is “parts by weight”, and “%” is “% by weight”.
It is.

I. Production Examples of Components for Cationic Electrocoating Base resin (A-1) Bisphenol A type epoxy resin with epoxy equivalent of 950 [trade name "Epicoat 1004, manufactured by Ciel Chemical Co., Ltd."]
1900 parts were dissolved in 993 parts of butyl cellosolve, 210 parts of diethanolamine was added dropwise at 80 to 100 ° C., and the mixture was kept at 100 ° C. for 2 hours. The base resin having a solid content of 68%, a primary hydroxyl equivalent of 528 and an amine value of 53 (A -1) was obtained.

Base resin (A-2) In a reaction vessel, 39 parts of monoethanolamine was kept at 60 ° C, 100 parts of N, N-dimethylaminopropylacrylamide was added dropwise, and the mixture was reacted at 60 ° C for 5 hours. A monoethanolamine adduct of propylacrylamide was obtained.

Separately, 950 parts of bisphenol A diglycidyl ether having an epoxy equivalent of 190, 340 parts of propylene glycol diglycidyl ether having an epoxy equivalent of 340, and bisphenol A456
Parts and 21 parts of diethanolamine were heated to 120 ° C., and reacted until the epoxy value became 1.02 mmol / g.After diluting with 479 parts of ethylene glycol monobutyl ether and cooling, while maintaining the temperature at 100 ° C., diethanolamine was added. 158 parts and 43 parts of the above N, N-dimethylaminopropylacrylamide monoethanolamine adduct were added, and the mixture was reacted until the increase in viscosity was stopped.
A base resin having a primary hydroxyl group equivalent of 518 and an amine value of 54 (A-
2) was obtained.

Substrate resin (A-3) 950 parts of bisphenol A diglycidyl ether having an epoxy equivalent of 190 and epoxy resin XB-4122 having an epoxy equivalent of 330
(Ciba-Geigy product name) 330 parts, bisphenol A45
Charge 6 parts and 21 parts of diethanolamine, raise the temperature to 120 ° C., react until the epoxy value becomes 1.02 mmol / g, dilute with 489 parts of ethylene glycol monobutyl ether, cool, and maintain the temperature at 90 ° C. While adding 126 parts of diethanolamine, 53.5 parts of the above-mentioned monoethanolamine adduct of N, N-dimethylaminopropylacrylamide and 18.5 parts of N-methylaminoethanol, the reaction was continued until the rise in viscosity stopped, and the resin solid content was 80%. A base resin (A-3) having a hydroxyl equivalent of 592 and an amine value of 55 was obtained.

Base Resin (A-4) A mixture of 103 parts of diethylenetriamine and 200 parts of methyl isobutyl ketone is heated to 100 ° C. to 160 ° C. to distill 36 parts of condensed water to obtain a diethylenetriamine ketimine compound. Separately, 1900 parts of a bisphenol A type epoxy resin having an epoxy equivalent of 950 [trade name "Epicoat 1004", manufactured by Ciel Chemical Co., Ltd.] are dissolved in 993 parts of butyl cellosolve,
109.5 parts of diethylamine and 133.5 parts of the above diethylenetriamine ketimine compound were added dropwise at 70 to 100 ° C., and then kept at 100 ° C. for 2 hours to obtain a base resin having a solid content of 68% and an amine value of 65 (A-
4) was obtained.

Base resin (A-5) Bisphenol A type epoxy resin with epoxy equivalent of 950 [Product name "Epicoat 1004", Ciel Chemical Co., Ltd.
1900 parts was dissolved in 993 parts of butyl cellosolve, 146 parts of diethylamine was added dropwise at 70 to 100 ° C., and the mixture was kept at 100 ° C. for 2 hours to obtain a base resin (A-5) having a solid content of 67% and an amine value of 55. Was.

Curing resin (B-1) 32.6 parts of EHPH3150 [epoxy equivalent: 175 to 195, manufactured by Daicel Chemical Industries, Ltd.] and 8.2 parts of propylene glycol monomethyl ether were heated and melted at 100 ° C. to give a solid content of 80% and an epoxy equivalent of 190. 40.8 parts of a curing resin (B-1) were obtained. The number average molecular weight of the resin was about 1,500.

Curing resin (B-2) 136 parts of vinylnorbornene oxide, 124 parts of 4-vinylcyclohexene-1-oxide and 18 parts of trimethylolpropane, 10% ethyl acetate solution of BF ₃ -etherate 2
00 parts was added dropwise at 50 ° C. over 4 hours to carry out ring-opening polymerization. Ethyl acetate was added and washed with water, and the ethyl acetate layer was concentrated.
Part was added dropwise at 50 ° C. over 4 hours as an ethyl acetate solution,
The mixture was further aged at 50 ° C. for 2 hours to carry out an epoxidation reaction. After removing acetic acid, ethyl acetate and peracetic acid, add 4 parts to 500 parts of ethyl acetate.
Dissolve at 0 ° C, then wash 4 times with 250 parts of distilled water, remove ethyl acetate, dissolve in 78 parts of propylene glycol monomethyl ether at 80 ° C, cure 80% solids, epoxy equivalent 202 Resin (B-2) is obtained. The number average molecular weight of the resin was about 1,300.

Curing Resin (B-3) 304 parts of partially epoxidized limonene (2-methyl-4-isopropenyl-1-cyclohexene oxide) and 18 parts of trimethylolpropane were added with 10 parts of BF ₃ -etherate.
200 parts of a 50% ethyl acetate solution was added dropwise at 50 ° C. over 4 hours. The following operation was performed in the same manner as for the curing resin B-2.
The resin was dissolved at 80 ° C. in 80 parts of ethylene glycol monobutylene ether to obtain a curing resin (B-3) having a solid content of 80% and an epoxy equivalent of 205. The number average molecular weight of the resin was about 1,000.

Curing Resin (B-4) Performed in the same manner as Curing Resin (B-2) using 304 parts of 2,4 or 1,4-dimethyl-4-ethenyl-1-cyclohexene oxide, solid content 80%, epoxy equivalent 199 curing resin B-4 was obtained. The number average molecular weight of the resin was about 950.

Curing resin (B-5) CELLOXIDE 3000 0.1 part of distilled water was added to 460 parts, trade name of Daicel Chemical Co., Ltd., 460 parts, aluminum acetylacetonate 0.3 parts and tetraethoxysilane 5 parts, and the mixture was kept at 80 ° C. for 1 hour.
After reacting at 3 ° C. for 3 hours, 116 parts of ethylene glycol monobutyl ether was added to obtain a curing resin (B-5) having a solid content of 80% and an epoxy equivalent of 280. The number average molecular weight of the resin is about 1,10
It was 0.

Curing resin (B-6) 132 parts of a dimer of cyclopentadiene was dissolved in 70 parts of ethyl acetate, and 160 parts of peracetic acid was added dropwise as an ethyl acetate solution at 35 ° C over 7 hours, and further at 40 ° C for 6 hours. Matured. After removing acetic acid, ethyl acetate and peracetic acid, add 4 parts to 500 parts of ethyl acetate.
The compound was dissolved at 0 ° C., washed 5 times with 250 parts of distilled water, and then ethyl acetate was removed. The compound was dissolved at 80 ° C. in 43 parts of methyl isobutyl ketone to obtain a compound (C) having a solid content of 80% and an epoxy equivalent of 90.
I got

94 parts of 4-vinylcyclohexene was dissolved in 75 parts of ethyl acetate, and 160 parts of peracetic acid was added dropwise as a solution of ethyl acetate at 50 ° C. over 4 hours, followed by aging at 50 ° C. for 2 hours. After removing acetic acid, ethyl acetate, and peracetic acid, the residue was dissolved in 500 parts of ethyl acetate at 40 ° C., and then washed five times with 250 parts of distilled water, and then ethyl acetate was removed. The compound was dissolved to obtain a compound (D) having a solid content of 80% and an epoxy equivalent of 65. To 225 parts of compound (C) and 163 parts of compound (D), 0.2 parts of aluminum acetylacetonate and 10 parts of trimethylolpropane were added, and the mixture was kept at 100 ° C for 1 hour.
After the reaction for 60 hours, 60 parts of ethylene glycol monobutyl ether is added and cooled. A curing resin (B-6) having a solid content of 70% and an epoxy equivalent of 210 was obtained. The number average molecular weight of the resin is about
It was 1,100.

Curing resin (B-7) A solution prepared by dissolving 2 parts of azobisdimethylvaleronitrile in 33.4 parts of METHB (3,4-epoxycyclohexylmethyl methacrylate) was heated at 100 ° C. to 10 parts of methyl isobutyl ketone and 10 parts of butyl cellosolve. The mixture was added dropwise over 2 hours, and after aging for 1 hour, the temperature was raised to 125 ° C., and the resin was further cured for 1 hour. 54 parts of a aging (B-7) solution for curing having a solid content of 60% and an epoxy equivalent of 196 were added Obtained. The number average molecular weight of the resin was about 10,000.

Curing resin (B-8) A solution obtained by dissolving 2.4 parts of azobisdimethyl valeronitrile in a mixture of 32.0 parts of METHB monomer and 8.0 parts of hydroxyethyl acrylate was dropped into 24 parts of butyl cellosolve heated to 100 ° C over 2 hours. After aging for 1 hour,
The temperature was raised to 125 ° C., and the mixture was aged for 1 hour to obtain 64.8 parts of a curing resin (B-8) having a solid content of 60% and an epoxy equivalent of 245. The number average molecular weight of the resin was about 12,000.

Curing resin (B-9) 3,4-epoxycyclohexylmethyl acrylate 37
Azobismethyl valeronitrile (2.4 parts) was dissolved in a mixture of 3 parts of hydroxyethyl acrylate and 3 parts of hydroxyethyl acrylate. Obtained. The number average molecular weight of the resin was about 15,000.

Pigment paste (P-1) 4.4 parts of 10% formic acid was added to 12.5 parts of base resin (A-2),
Add 15 parts of deionized water with stirring. More titanium white 15
Parts, 5 parts of clay, 1 part of carbon, and 2 parts of basic lead silicate, and dispersed for 24 hours in a ball mill, followed by addition of 11 parts of deionized water to obtain a pigment paste having a solid content of 50%.

Pigment paste (P-2) Pigment paste (P-2) was obtained by treating in the same manner as pigment paste (P-1) except that 2 parts of basic lead silicate was replaced with 3 parts of basic lead sulfate.

Pigment paste (P-3) 12.5 parts of base resin (A-2) was added to base resin (A-4) 14.7 parts.
A pigment paste (P-3) was obtained by treating in the same manner as the pigment paste (P-1) except for changing the parts.

II. Production Example of Cathodic Electrodeposition Coating The basic resin and the curing resin obtained in Production Example A were used to prepare an aqueous emulsion to obtain a cationic electrodeposition coating material used in the present invention. The compositions and amounts are shown in Table 1 below.

III. Example The cationic electrodeposition paint (solid content) obtained in Production Example II above
450 parts of a 20% aqueous dispersion) are mixed with 66 parts of the pigment paste and 99 parts of deionized water to prepare a 20% electrodeposition bath. Bath temperature
It was electrodeposited on a zinc phosphate treated steel sheet at 200C to 300V for 3 minutes at 30C and baked at 160C for 30 minutes to obtain a cured coating of 15 to 23 microns.

Then, an intermediate coating [Amirac N-2 Sealer (polyester resin-based coating), manufactured by Kansai Paint Co., Ltd.] is applied to the electrodeposited coating film surface to a thickness of 25 to 35 μm based on the cured film thickness. It was cured by heating at 140 ° C. for 30 minutes. The intermediate coating may be omitted.

Further, when the above-mentioned electrodeposition coating film surface was directly or intermediate-coated, a top coat was applied to the intermediate coating surface.
The topcoat is divided into a solid color finish and a metallic finish. First, the solid color finish is "Magiclon @ 300 White" [Kansai Paint Co., Ltd.
(Trade name, thermosetting acrylic resin / amino resin overcoat) based on the cured coating film to a thickness of 30 to 40 μm, and baked at 140 ° C. for 30 minutes to cure (one coat 1)
Baking method). Metallic finish is “Magiclon 300 Silver” [manufactured by Kansai Paint Co., Ltd., trade name, thermosetting acrylic resin / melamine resin / cellosol acetate butyrate resin-based metallic paint] based on the cured coating film. After coating to a thickness of 20 μm, then, without curing the metallic coating, apply “Magiclon @ 300 Clear” [Kansai Paint Co., Ltd., trade name, thermosetting acrylic resin / melamine resin system] Clear paint] was applied to a thickness of 35 to 40 μm based on the cured coating film, and then heated at 140 ° C. for 30 to simultaneously cure both coating films (two-coat one-bake method).

IV. Performance test results Performance tests were performed on the coating films obtained in the above examples. Table 2 below shows the coating steps and test results of the examples.

(* 1) Coating step Electrocoating: As described above, any one of the pigment pastes (P-1) to (P-3) and deionized water are mixed with the cationic electrodeposition coating obtained in Production Example II. % Electrodeposition bath was used. The numbers in the same column correspond to the cationic electrodeposition coating Nos. Described in Table 1 obtained in Production Example II, and the above components are blended therein. The pigment paste (P-1) is for the cationic electrodeposition coatings 2, 4 to 11 and 13, (P-2) is for the cationic electrodeposition coatings 1 and 3, and (P-3) is for the cationic electrodeposition coating 12. Respectively.

In the cationic electrodeposition paint used in Comparative Example 14, Comparative Example 14 was obtained by completely blocking 37.5 parts of the curing resin (B-1) in Example 1 with diphenylmethane diisocyanate using 2-ethylhexyl monoetherified ethylene glycol. Comparative Example
Reference numeral 15 denotes a resin in which the curing resin (B-1) 37.5 in Example 2 was replaced with 33 parts of the above-mentioned completely blocked product. In addition, these electrodeposition paints were mixed with 3 parts of dioctyltin oxide as a catalyst per 100 parts of the total weight of the base resin and the curing agent. Coating conditions and baking of the cationic electrodeposition paint in the comparative example.

Intermediate coating: Intermediate coating and the coating conditions are as described above. In the same column, “○” indicates that intermediate coating was performed, and “−” indicates that it was omitted.

Top coat: The top coat and the coating conditions are as described above, and “S” in the same column is a solid color finish, and “M” is a metallic finish.

(* 2) Performance Test Results heating loss: which was examined weight loss before and after baking the cationic electrodeposition coating, the weight of the zinc phosphate treated sheet as W _0, 3 minutes electrodeposition after wear 30 ° C. This process plate Dry under reduced pressure in a vacuum dryer at 80 ° C. for 1 hour. The weight of this compound and W _1, dryer at 180 ° C., the weight after baking 30 minutes and W _2. The heating loss ΔW is calculated from the following equation.

Sharpness: Measured by an image clarity measuring device [IMAGE CLARITY METER: manufactured by Suga Test Instruments Co., Ltd.]. Numbers in the table are ICM values from 0 to 100
%, The larger the numerical value, the better the sharpness (image clarity). If the ICM value is 80 or more, the sharpness is extremely excellent.

Adhesion: A zinc-plated steel sheet treated with zinc phosphate was used as the substrate to be coated. The coated top plate was immersed in water at 40 ° C for 20 days, dried at room temperature for 24 hours, and then subjected to JIS K5400-1.
979 A gobang is formed on the coating film according to 6.15, an adhesive cellophane tape is adhered to the surface, and the coated surface after being rapidly removed is evaluated.

：: No peeling is found at all. △: 1 to 10 peeling marks are found. ×: 11 or more peeling marks are found. Yellowing: Topcoat film (solid color) at 160 ° C. is 3
The change from baking for 0 minutes and baking at 140 ° C for 30 minutes was examined by measuring Δb with a colorimeter (manufactured by Murakami Color Materials Laboratory Co., Ltd.). A smaller value indicates less yellowing and bleeding. .

Curing inhibitory property: The state of the coated surface after 10 reciprocal rubs with a gauze impregnated with xylol was examined.

：: No abnormality such as gloss was observed at all. △: Little gloss was observed. ×: Remarkably gloss was generated. And measure the rust and blister width from the knife wound.

 ○: less than 1 mm △: less than 1 to 3 mm ×: 3 mm or more

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Reijiro Nishida 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Kansai Paint Co., Ltd. (72) Koji Morino 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Kansai In Paint Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) C09D 5 / 44,163 / 00-163/10

Claims (9)

(57) [Claims] 1. A resin (A) having a hydroxyl group and a cationic group, and an epoxy group-containing functional group in which an alicyclic skeleton and / or a bridged alicyclic skeleton is bonded to an epoxy group, has an average of 2 per molecule. A method for forming a coating film, comprising applying a cationic electrodeposition coating material containing at least one epoxy resin (B) as a main component, and then applying a top coating material on the coated surface. 2. A coating film forming method, comprising applying the cationic electrodeposition coating composition according to claim 1, applying an intermediate coating composition on the coated surface, and then applying a top coating composition on the intermediate coating surface. Law. 3. The method according to claim 1, wherein the resin (A) is a resin containing a primary hydroxyl group and a cationic group. 4. The method according to claim 1, wherein the resin (A) is a reaction product obtained by reacting a cationizing agent with an epoxy group of a polyepoxide compound obtained from a polyphenol compound and epichlorohydrin. . 5. The epoxy resin (B) having an epoxy group-containing functional group represented by the following formulas (I) to (IV): Wherein R ₁ , R ₂ , R ₃ , R ₅ , R ₆ , R ₇ , R ₁₀ and R ₁₁ each represent H, CH ₃ or C ₂ H ₅ , and R ₄ , R ₈ and R ₉ are The coating film forming method according to claim 1, wherein the method is at least one selected from the group consisting of H and CH ₃ . 6. An epoxy resin (B) having the following formula (V): The coating film forming method according to claim 5, which has an epoxy group-containing functional group represented by the formula: 7. An epoxy resin (B) having the following formula (VI) The coating film forming method according to claim 5, which has an epoxy group-containing functional group represented by the formula: 8. One or more metal compounds selected from the group consisting of lead compounds, zirconium compounds, cobalt compounds, aluminum compounds, manganese compounds, copper compounds, zinc compounds, iron compounds, chromium compounds and nickel compounds, 3. The coating film forming method according to claim 1, wherein a cationic electrodeposition paint containing a metal content of 10% by weight or less based on the total weight of A) and epoxy resin (B) is used. 9. A coated product coated by the method according to claim 1.