JPS5910373A - Cationic electrodeposition painting method - Google Patents

Abstract

PURPOSE:To form a painted film having a high grade at a low temp., by subjecting a substrate to electrodeposition painting in a cationic electrodeposition painting bath consisting of a specific polyamino resin soln. then to a spray painting of an acrylic resin soln. and burning the same simultaneously to cure the paint. CONSTITUTION:A polyamino resin to be used is the resulted product of reaction of polyepoxide and the 1st amine having the 1st amine group or the 2nd amine group, or the resulted product of reaction of polyepoxide and ketimine blocked polyamine contg. the 1st amine group. A conductive substrate as a cathode is subjected to electrodeposition painting in a cationic electrodeposition paint bath consisting of such polyamine resin soln. and after washing, a spray paint consisting of a resin soln. contg. (meth)acryloyl is spray painted on the painted film thereof. These paints are burned simultaneously for 10-40min at 150-190 deg.C to cure, whereby the cured and painted film having 30-50mu film thickness and high performance is obtd.

Description

[Detailed description of the invention] The present invention relates to a cationic electrolytic Il coating method.

Although the rust prevention of automobile bodies has been significantly improved by the introduction of cationic electrodeposition paints, it has not yet reached a fully satisfactory level.

In particular, physical properties of the coating film, such as secondary adhesion, chipping resistance, and corrosion resistance, are in need of improvement.

Additionally, conventional cationic electrodeposition paints that are cured using printed isocyanate have inherent drawbacks, such as higher baking temperatures and higher amounts of smoke and tar compared to anionic electrodeposition paints. have.

The present inventors, in order to solve such problems and drawbacks,
As a result of intensive research, we have found that the above problems can be significantly improved by applying a new cross-linking and thermosetting reaction (Michael (mlehmel) type addition reaction) technology that is completely different from conventional technology. This is the headline that led to the completion of the present invention.

That is, the present invention uses a cationic electrolyte paint bath consisting of a polyamine resin solution having a 176 amine group or a secondary amine group to perform electrodeposition coating on an electrically conductive object as a cathode. A cationic electrodeposition coating characterized by spraying a 511F material consisting of a resin solution having a 7-acrylic group or a methacrylic group, and curing the cationic electrodeposition II paint film and the spray paint film at the same time. It is about law.

The polyamine resin having a primary amine group or a secondary amine group (hereinafter simply referred to as polyamine resin) used in the present invention includes, for example, a reaction product of polyepoxide and a primary amine, a polyepoxide and a ketimine-blocked primary amine, etc. Examples include reaction products with group-containing polyamines.

The polyepoxide is a compound having one or more 1.2 epoxy functional groups, for example, firstly poly7E/-
polyglycidyl ethers (obtained by etherifying polyphenols with epiflurhydrin or dichlorohydrin in the presence of an alkali)
etc.

Here, examples of polyphenols include 2°diphenyl)ethane, 2-methyl-1,l-bis(4-hydroxyphenyl)propane, 2,2-his(4-hydroxy-5-t-butylphenyl)propane, bis( 2-Hytruxinaphthyl)methane.

Examples include 1,5-dihydroxy-naphthalene.

Also used are oxyalkylated adducts (for example, ethylene oxide adducts or propylene oxide adducts of polyphenols), novolac type phenol resins, and polyphenol resins similar to these.

Other polyepoxides include, for example, epoxidized polyalkadiene resins, glycidyl (meth)acrylic copolymer resins, polyglycidyl ethers of hydroxyl group-containing resins, and polyglycidyl esters of carboxyl-containing resins.

Polyepoxide is further reacted to cause chain extension,
Its molecular weight may be increased. In this case, the chain extender may be an active hydrogen-containing compound that is reactive with an epoxy group, such as a hydroxyl group, a thiol group, a carboxyl group,
Compounds containing secondary amine groups (for example, dimer acids, polyether polyols, polyester polyols, hydantoins, bisphenol A, polyamides, amino acids, etc.) can be mentioned.

The polyepoxide reacts with amines (primary amines, ketimine-blocked polyamines containing primary amine groups) to form polyamine resins.

As the primary amine, monoamines (eg, propylamine, butylamine, amylamine, 2-ethylhexylamine, monoethanolamine, etc.) are preferred.

The primary amine reacts with the epoxy group to form a secondary amine group that is useful for subsequent crosslinking reactions.

As the ketimine polyamine containing a 17th amine group, the primary amine group in a polyamine (e.g., diethylenetriamine, dibu-pyrenetriamine, diethylenetriamine, triethylenetetramine, etc.) is a ketone (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Examples include those converted to ketimine by reaction with

After the ketimine-blocked polyamine containing a primary amine group reacts with an epoxy group, the ketimine group is hydrolyzed by the addition of water, and a primary amine group useful for the subsequent structuring reaction is formed. .

By neutralizing the amine group with an acid, the polyamine resin can be converted into a cationic base and an aqueous dispersion (cationic electrodeposition coating) can be formed.

Here, the acid is an organic acid or an inorganic acid, such as formic acid, acetic acid, lactic acid, phosphoric acid, and the like.

The molecular weight and structure of the component 30 to 1 of the theoretical total neutralization equivalent are determined by the dispersion stability when the polyamine resin is mixed with an aqueous medium, the electrodeposition properties described below, the crosslinking curability, Mutual adjustments must be made taking into account factors such as coating film performance.

By immersing an anode and a negative (electroconductive coating material) in an aqueous dispersion of polyamine resin (cationic electrodeposition paint) and applying a voltage between the two electrodes, the re-electrodepositable resin will be applied to the surface of the cathode. Precipitate.

Such cationic electrocoating techniques are well known in the art, but the deposited coating is one that is not redissolved in the aqueous dispersion (cationic electrocoat) bath [and is easily removed from the bath]. In subsequent washing with water, the amount of sagging due to insensitivity to water pressure and the concentration of the aqueous dispersion of polyamine resin (cationic electrodeposition coating) are mutually dependent on each other. The selection is li#.

In the crosslinking and thermosetting reactions in the present invention, the active hydrogen atoms of the primary amine group or secondary amine group of the cationic electrodeposition paint film form the (meth)acrylic 2yl group of the spray 11 paint film in the next step. The curing method is mainly based on a Michael type addition reaction that adds to a carbon-carbon double bond, but if necessary, a conventional curing method using a blocked incyanate may be used in combination.

Polyamine resin is produced by a conventional method, and an example of the basic process is as follows.

Charge some or all of the polyepoxide into a reaction vessel,
Mix under a stream of inert gas to form a homogeneous liquid. If necessary in this step, heating, addition of a suitable organic solvent, preliminary reaction of the polyepoxide with other components such as bisphenol A, etc. can be carried out.

The amines are added to the above homogeneous liquid at an appropriate temperature while stirring under an inert gas stream.The addition of the amines is carried out by methods such as total charging, split charging, and dropwise charging. The types of amines and
You can change the amount. At this stage, heating, cooling,
Refluxing of volatile components, addition of a portion of the polyepoxide, solvent, etc. can be carried out.

After the addition of the amines is completed, the reaction is continued at an appropriate temperature and time as necessary. If necessary, other components are added and reacted, and the steps of dilution with a solvent, distillation, and filtration are carried out. to obtain a polyamine resin solution.

The polyamine resin solution contains neutralizing agent (acid), solvent, water, pigment, etc., and DeSilver, which is commonly used in the manufacture of paints.
Homo mixer, sand grind mill, attritor,
Mix uniformly using a mixer such as a roll mill or a trap such as a disperser to reduce the solid content (polyamine resin content) to approximately 10% by weight.
A cationic electrodeposition paint bath which is an aqueous dispersion having a concentration of 2S or less by weight is prepared. Next, an electric current is passed between the anode and the cathode (conductive coating material) through the obtained cationic electrodeposition paint bath. , depositing a coating layer on the cathode.

Here, the solvent is a hydrophilic or semi-hydrolytic solvent conventionally used in electrodeposition paints, such as isopropyl alcohol, butyl alcohol, ethyl cellosolve,
Examples include butyl cellosolve, diacetone alcohol, etc., and examples of pigments include titanium dioxide, carbon black, and talc.

Examples include kaolin, silica, and lead silicate.

Resin having one or more 7-acryloyl group or methacryloyl group in the molecule used in the present invention [hereinafter referred to as (meth)
Examples of acryloyl group-containing resins include reaction products of polyepoxides (similar to the polyepoxides used in the above-mentioned polyepoxides) and acrylic acid or methacrylic acid, carboxyl group-containing resins (for example, carboxyl group-containing resins), and acrylic acid or methacrylic acid. reaction products of glycidyl acrylate or glycidyl methacrylate,
Hydroxyl group-containing resins (e.g. reaction products of polyepoxides with monoalcohols or phenols, polyether polyols that do not contain epoxy groups obtained by reacting polyepoxides with excess polyhydric alcohols, hydroxyl group-containing acrylic polymers, polyesters derived from lactones) transetherification reaction products of polyols, hydroxyl group-containing polybutadiene, etc.) and N-alkoxymethylacrylic 7mide or N-flukoxymethylmethacrylamide, terminal incyanate prevomers and hydroxyalkyl acrylates or human-xyalkyl methacrylates. Examples include reaction products.

The molecular weight, structure and composition of the (meth)acryloyl group-containing resin, the ratio of acrylic groups or methacryloyl 12- groups, etc. should be determined depending on the desired properties of the final product. For example, the content of acryloyl or methacypyl groups should be 9 or more per molecule in order to obtain sufficient crosslinking density during curing, but if it exceeds 6 is likely to gel during the reaction of introducing an acryloyl group or a methacrylic acid group, so the number is preferably 1 to 6, particularly preferably 2 to 3.

The reaction product of polyepoxide and acrylic acid or methacrylic acid is usually prepared by mixing 2 moles of acrylic acid or methacrylic acid with 1 mole of polyepoxide, a tertiary amine catalyst, and a known heavy inhibitor at 1c, 100%. It can be obtained by carrying out the reaction at a reaction temperature of around 0°C. In this reaction, a suitable organic solvent is added, and heating, cooling, and refluxing of volatile components are carried out under an inert gas stream by methods such as total charging, dividing charging, and dropping charging.

Among the reaction products of polyepoxide and acrylic acid or methacrylic acid, those represented by the following general formula are preferred.

A reaction product of a carboxyl group-containing resin and glycidyl acrylate or glycidyl methacrylate can also be obtained by a method similar to the method used to obtain the reaction product of polyepoxide and acrylic acid or methacrylic acid.

The reaction product of a hydroxyl group-containing resin and N-alkoxymethylacrylamide or N-1alkoxymethylmethacrylamide is usually prepared in the presence of a heavy inhibitor and an acid catalyst, preferably p-)luenesulfonic acid. , 60-200
Heating at 1°C, preferably from 80 to 160'O, is followed by a transetherification reaction (to carry out the reaction completely, the alcohol formed is either distilled off at atmospheric pressure or under reduced pressure, or
Alternatively, it is removed as an azeotrope with a solvent, preferably a hydroxyl group-free solvent. ) can be obtained by doing

The (meth)acryloyl group-containing resin is made from a hydrophilic solvent, a pigment, and DeSilver, which is commonly used in the production of room materials.
Homo mixer, sand grind mill, 7 triter,
A hydrophilic solvent dispersion is obtained by uniformly mixing using a mixer such as a roll mill or a dispersing machine. The aqueous dispersion can also be obtained by a method similar to the method for obtaining the hydrophilic solvent dispersion, but the third method is
It is preferred that at least a portion of the amine groups be neutralized with an acid and converted into a cationic base to aid dispersibility in water. - Examples of pigments include titanium dioxide, carbon black, talc, kaolin, silica, lead moon, cyanamide ship, basic lead rimate, basic lead sulfate, zinc rimate, merium chromate, Stuntium phosphate, Riμ
Examples include calcium chlorate, zinc phosphate, and zinc molybdate.

The present invention uses a cationic electrodeposition paint made of the above-mentioned polyamine resin solution and a spray paint made of a (meth)7cryl 15-yl group synthetic resin solution (parent, aqueous solvent dispersion or water dispersion). Next, in Example 5, a cationic electrodeposition paint bath consisting of a polyamine resin solution is used as a cathode for a conductive object to be coated with Electrode II' in the same manner as ordinary cationic electrodeposition coating, 1 on the undried cationic electrodeposition paint film immediately after washing with water, or cationic fl that has been pre-dried at 50-120°0 for 5-60 minutes after washing with water! A spray paint consisting of a (meth)acryloyl group-containing resin solution (hydrophilic solvent dispersion or water dispersion) is applied onto the deposited paint film, and the cationic electrodeposition paint mi and spray 11 paint film are coated with a coating film of 150 to 190%. The thickness [(3O
~50μ) and has excellent adhesion, flexibility, chipping resistance, water resistance, alkali resistance, acid resistance, etc. Cured #III! is obtained.

Next, the present invention will be explained in further detail with reference to production examples, working examples, and comparative examples. In the examples, parts are parts by weight, and
It is.

16-Manufacturing Example 1 (Cation made of polyamine resin solution [coating A] In the reaction vessel, polyepoxide (made of oil-based shell epoxy ■,
Epicote +1001. Epoxy equivalent 45 obtained by reaction of bisphenols and shrimp coolhydrin
0 to 500 epoxy resin) and 24 parts of xylene were charged, and the temperature was gradually raised to 140 to 150'0 to remove water present in the resin.

Then, 45 parts of dimer acid (manufactured by Daiichi General ■, Persatime 42xs) and 1 part of dimethylethanolamine were added, and the mixture was maintained at 120'O for about 2 hours. After the acid value was below 1, it was cooled to 80"0 and 126 parts of diketimine (made from 1 mole of diethylenetriamine and 2 moles of methyl isobutyl ketone) were added.

Then, after holding at 8 G-JI OOoo for about 1 hour, the temperature was raised to 12 G'0, xylene was removed under reduced pressure, 222 parts of ethyl cellosolve was added, and the mixture was cooled to room temperature to obtain a polyamine resin solution.

To 100.0 parts of the obtained polyamine resin solution, 6.8 parts of acetic acid and 405.0 parts of deionized water were added to obtain a cationic electrodeposition paint A having a polyamine resin content of 13%.

Production Example 2 (Coating B with Cation 1 consisting of a polyamine resin solution) 532 parts of polyepoxide (previous Production Example 1) and 28 parts of xylene were charged in a reaction vessel, and the temperature was gradually raised to 140-150°0. Water present in the resin was removed.

Next, 66 parts of xylene and 34 parts of dimethylhydantoin were added, and the mixture was kept at 140°C for 3 hours, cooled to 80°C, and 92 parts of diketimine (Preparation Example 1) and 59 parts of monoethanolamine were added. Ta.

Then, after maintaining the temperature at 80 to 100°0 for 1 hour, 252 parts of Putrusep Solp was added, and the mixture was cooled to room temperature to obtain a polyamine resin solution.

8 parts of acetic acid per 100 parts of the obtained polyamine resin liquid.
1 part, 392 parts of deionized water was added, and the polyamine resin part was 13 parts.
% of cationic ff1-coated paint B was obtained.

Production Example 3 (Cationic electrodeposition paint C made of polyamine resin solution) Using the polyamine resin solution obtained in Production Example 1, the following mixing direction was dispersed with a sand grinder, and then
Furthermore, 2,580 parts of deionized water was added to obtain a cationic electrodeposition paint C having a solid content of 18 inches.

Polyamine resin solution 100.0 parts Titanium dioxide 17.0 + Carbon black 1.2 Takaolin
8.0 Minor acetic acid
7.0# deionized water 123.
0# Production Example 4 (Cationic electrodeposition paint D consisting of polyamine resin solution) Using the polyamine resin solution obtained in Production Example 2, 19- After dispersing the following mixture in a sand grind mill,
In addition, 3ts of deionized water6. o@ was added to obtain a cationic electrodeposition paint with a solid content of 17.

Polyamine resin solution 100.0 parts Titanium dioxide 15.041 Carbon black 0.5 Nakaolin
7.0 Minor acetic acid
8.0 deionized water 117.
0-manual production example 5 [Spray paint A consisting of (meth)acrylic group-containing resin solution] In a reaction vessel, 4111 parts of polyepoxide (preparation example above), 11 parts of methyl isobutyl ketone, and 30 parts of methanol of tetramethylammonium chloride were added. 6 parts of the solution and 53 parts of acetic acid were charged and heated at 110°0 for 4 hours to evacuate the room and form a polyol.

Then, after adding 7 parts of a 40% solution of ethyl Celsolve %p-)luenesulfonic acid (transetherification catalyst a), the pressure in the reaction vessel was brought to about 25-220-71111H#.

Then, 14 tl of N-7' toxymethyl acrylamide
9 parts of a 30% solution of hydroquinone (polymerized #IL agent) in ethyl cellosolve was added over 1 hour at 130-135°C.

Then, the butanol that had been reduced by the transetherification reaction was distilled off under reduced pressure for about 5 hours. After the pressure in the reaction vessel was brought to atmospheric pressure with nitrogen gas, butyl cellosolve was added. A (meth)acryl group-containing resin solution (R aqueous solvent dispersion, resin content 58%) was obtained.

100 parts of the resulting (meth)acryloyl group-containing resin solution was diluted with 3 parts of ethyl cellosolve and 56 parts of isopropyl alcohol to obtain spray paint A.

Production Example 6 [Spray paint B consisting of (meth)acjlp+yl group-containing resin solution] In a reaction vessel, 606 parts of polyepoxide (preparation example 1), 280 parts of ethyl cellosolve, 94 parts of acrylic acid, and 30 parts of ethyl cellosolve of hydroquinone were added. 13 parts of a 30% solution of tetramethylammonium chloride in methanol and 7 parts of a 30% solution of tetramethylammonium chloride in methanol were heated at 130'0 for 5 hours under nitrogen gas to defunctionalize the resin solution (meth)acryloyl group-containing resin solution (hydrophilic solvent). A dispersion with a mallet fat content of 70 g was obtained.

Spray paint B was obtained by diluting 100 parts of the obtained (meth)acryloyl group-containing resin solution with 53 parts of ethyl cellosolve and 80 parts of isopropyl alcohol.

Production example [(meth)ac IJ Spray Sm material C consisting of p+yl group-containing resin solution] Epoxidized polybutadiene resin (number average molecular weight t100.1, 2-bond 87.8, trans 1.4
- an epoxidized product of liquid polybutadiene with a bond of 1O12% and an oxirane oxygen content of 8.3%) containing rsoo part and butyl selonup SOO part,
While stirring, maintain the temperature at 70°0 and add dimethyl 7! +o
% aqueous solution was added dropwise over 30 minutes.

Next, 2 parts of human-quinone was added, and 130 parts of acrylic acid was gradually added dropwise while maintaining 90'CVc.The addition reaction was continued for 7.4 hours to introduce acrylicyl 7&, and the resin solution (
Resin content: 70%) was obtained.

The obtained resin solution was neutralized with 1 mole of acetic acid equal to the argon group in the resin solution, and then diluted with deionized water to obtain a (meth)7 acryloyl group-containing resin solution (aqueous dispersion, resin minutes 50
%) was obtained.

Spray material C was obtained by diluting 100 parts of the obtained (meth)acryloyl group-containing resin solution with 29 parts of ethyl cellosolve and 36 parts of deionized water.

Example 1 The cationic electrolyte 11 paint A obtained in Production Example 1 was applied at a bath temperature of 27°0 and an applied voltage of 12 using a zinc phosphate treated steel plate as a cathode.
Electrodeposition coating (film thickness 22μ) was applied under the conditions of 0V and 2 minutes of current.
), rinsed with water, and air-buried thoroughly. Spray paint A obtained in Production PI 5 was applied to the undried coating film obtained in Production PI 5.
A test piece was obtained by applying a protective coating and baking it (160°C for 20 minutes and 110°C for 20 minutes).

The obtained test pieces were tested for acetone resistance, pencil hardness, impact resistance, bending resistance, etc.

The test results are shown in Table 117.

Example 2 Manufacturing example? The obtained cationic electrodeposition paint B was heated to a bath temperature of 27° C. and an applied voltage of 140° C. using a zinc phosphate treated steel plate as a cathode.
V, electrodeposition amount 1k (film thickness 21μ) under the conditions of 2 minutes of current application time.
), water washing 1~, and sufficient air blowing to obtain an undried coating film, and the spray paint B obtained in Production Example 6 was spray-coated and baked in the same manner as in Example 1. A test piece was obtained.

The obtained test piece was subjected to the same test as in Example 1.

The test results are shown in Table 1.

Example 3 The cationic electrodeposition paint A obtained in Production Example 1 was applied at a bath temperature of 27° C. and an applied voltage of 120° C. using a zinc phosphate treated steel plate as a cathode.
V, electrodeposition coating (film thickness 21P) under the condition of 2 minutes of current application.
After washing with water, thoroughly blowing with -24= air, and pre-drying at 110°C for 25 minutes, the spray paint Ct obtained in Production Example 7 was spray-coated, and the same coating as in Example 1 was applied. A test piece was obtained by baking as described above.

The obtained test piece was subjected to the same test as in Example 1.

15. The test results are shown in Table 1. .

Example 4 The cationic electrodeposition paint C obtained in Production Example 3 was applied at a bath temperature of 28°C and an applied voltage of 200°C using a zinc phosphate treated steel plate as a cathode.
V, electrodeposition coating (film thickness 20μ) under the condition of 3 minutes of current application.
After that, the undried coating film obtained by washing with water and thoroughly blowing with air was mixed with 100.0 parts of the (meth)acryloyl group-containing resin solution obtained in Production Example 5, and 46.0 parts of butyl cellosolve. 63.6 parts of titanium dioxide, 27.0 parts of kaolin, 50 parts of silica, 0.4 parts of carbon black, and 4.0 parts of strontium chromate were dispersed using a sand grind mill, and 61 parts of Improvil alcohol was added to the mixture.
A test piece was obtained by spray painting the spray paint (gray color) D obtained by adding 0 parts and baking at 170°C for 25 minutes.

Regarding the obtained test pieces, the appearance of the coating film, corrosion resistance, adhesion,
Tests were conducted on impact resistance, toughness (Erichsen value), chipping resistance, water resistance, alkali resistance, acid resistance, etc.

The test results are shown in Table 2.

Example 5 The cationic electrodeposition paint obtained in Production Example 4 was applied at a bath temperature of 28° C. and an applied voltage of 240° C. using a zinc phosphate treated steel plate as a cathode.
V, electrodeposition coating (film thickness 21μ) under the condition of 3 minutes of current application.
After that, the spray paint (gray color) D obtained in Example 4 was spray-coated on the undried coating film obtained by washing with water and thoroughly blowing with air, and baking it at 170°C for 25 minutes. A test piece was obtained.

The same test as in Example 4 was conducted on the obtained test piece.

The test results are shown in Table 2.

Example 6 Butyl cellosolve 550 was added to the wet film of the cationic electrodeposition paint obtained in Example 5 based on 1/1 part of the (meth)acryloyl group-containing resin solution obtained in Production Example 6. parts, titanium dioxide 49.0 parts, talc 34.0 parts
part, 18 parts of silica, 1 or 2 parts of carbon black, and aO part of zinc phosphate were dispersed using a sand grind mill.
110 parts of butyl cellosolve, 4 parts of isopropyl alcohol
A test piece was obtained by spraying paint (gray color) E obtained by adding 1 part of LO and baking at 17.0°C for 25 minutes. □The obtained test piece was subjected to the same test as in Example 4. □ Check out the test results! It was shown to. 4, Comparative Example 1 &4-totolylene diisocyanate 1652 in the reaction vessel,
Add 5.0 parts of methyl isobutyl ketone and add 3.0 parts of methyl isobutyl ketone while stirring.
While keeping the temperature below 0°C, 488 parts of 2-ethylhexanol was added dropwise over about 5 hours (to obtain a semi-blocked product of -1λ4-tolylene diisocyanate with 2-ethylhexanol).

In addition, 507 parts of polyepoxide (preparation example 1 - 27 above) and 24 parts of xylene were charged in another reaction container, and 140 parts of xylene were charged.
The temperature was gradually raised to ˜150° O1 to remove water present in the resin.

Then, it was cooled at 110°C, and 50 parts of methyl isobutyl ketone was added to the 2-ethylhexanol semi-blocked product of 2.4-) lylene diisocyanate.
and heated at 120°C for 1 hour.゛Then, polycaprolactone diol (manufactured by Union Carbide,
pcpOjJQO) and 0.4 parts of benzyldimethylamine were added, and the mixture was heated at 130''C for 4 hours, and then 260 parts of methyl isobutyl ketone was added.

Then, it was cooled at 80°ct, 35 parts of diketimine (preparation example 1 above) and 31 parts of diethylamine were added, and 111i
After heating in O for 3 hours, 157 parts of ethylseron was added, and the mixture was cooled to room temperature to obtain a polyamine resin solution.

7 parts of acetic acid per 100 parts of the obtained polyamine resin solution.
13 parts, and 426 parts of deionized water were added to give a total of 13 parts of boria-carbon resin.
A cationic electrodeposition paint was obtained.

28- The obtained cationic electrodeposition paint was electrodeposited (film thickness: 21 μm) using a zinc phosphate treated steel plate as a cathode under the conditions of bath temperature of 27°C, applied voltage of 120μ, and current application time of 2 minutes.
After washing with water and thoroughly blowing with air, it was baked in the same manner as in Example 1 to obtain a test piece.

The obtained test piece was subjected to the same test as in Example 1.

The test results are shown in Table 1.

Comparative Example 2 Using the polyamine resin solution obtained in Comparative Example 1, the following mixture was dispersed using a sand grind mill, and then 2,510 parts of deionized water was added to obtain a cationic electrodeposition paint with a solid content of 18 inches.

Polyamine resin solution 1000 parts diptyltin div-ureate, 1.1# titanium dioxide
17.0 #Carbon black
l, 2# kaolin
&OI, acetic acid
7. Ol deionized water 12λ0#
The obtained cationic electrodeposition paint was electrodeposited (film thickness 21 μm) using a zinc phosphate treated steel plate as a cathode under the following conditions: bath temperature 28°C, applied voltage 240v, energization time 3 minutes.
After washing with water and thoroughly blowing, a test piece was obtained by baking at 170'O for 25 minutes.

The same test as in Example 4 was conducted on the obtained test piece.

The test results are shown in Table 2.

31- Table 2 Note (1) Width of removing seven Rohan deeps in the scratch area 3
N or more yen.

(Twenty diamonds shaped according to the 21 ASTM method were applied to the coating from a certain distance, and the corrosion resistance after 240 hours of salt water spraying was evaluated at 5 drop points.

Patent applicant: NOF Corporation 32- Procedural amendment ml (voluntary) August 24, 1980 Director-General of the Patent Office Kazuo Wakasugi 1, Indication of the case 1982 Patent Application No. 118200 2 Name of the invention: Cationic electrodeposition Coating method 3 Relationship with the case of the person making the amendment Column 5 Detailed explanation of the invention of the patent applicant No. 1 O-1, Yurakucho, Chiyoda-ku, Tokyo Notooshi correction.

fil On page 28 of the specification, lines 18-19, ``For 100 parts of the obtained polyamine resin solution, 7 parts of acetic acid,
Add 426 parts of deionized water to 100.0 parts of the resulting polyamine resin solution.

11 parts of dibutyltin dilaurate, 7.0 parts of acetic acid.

Add 4260 parts of deionized water.''

that's all

Claims (1)

[Claims] Electrodeposition is carried out using a cationic electrodeposition paint bath consisting of a polyamine resin solution having a primary amine group or a secondary amine group, and then electrodeposition is performed using a conductive coating material as a cathode. A cationic electrolytic sI coating method, which comprises spraying a spray paint made of a resin solution having a methacrylyl group, and simultaneously baking and curing the cationic 71t It paint film and the spray paint film.