JPH09104838A - Resin composition for aqueous coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition giving cured coating films having good processed part adhesivity, hardness and appearance, even after subjected to retort treatments, and useful for coating the outer surfaces of cans, etc., by mixing a specific new aminoformaldehyde resin with an aqueous resin. SOLUTION: This resin composition for aqueous coatings comprises (A) 50-99wt.% of an aqueous resin having an acid value (as for the solid content) 20-100 and a hydroxyl group value (as for the solid content) of 10-150 and (B) 50-1 wt.% of an amonoformaldehyde resin. The component B is obtained by the addition reaction of formaldehyde to a norbornanediguanamine of formula I (the bound positions of the 4,6-diamino-1,3,5-triazin-2-yl groups are 2,5- or 2.6- positions) and/or a cyclohexanediguanamine of formula II (the bound positions of the 4,6-diamino-1,3,5-triazin-2-yl groups are 1,2-, 1,3- or 1,4-positions) and the etherification reaction of the reaction product with an alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for water-based paints, and more specifically, in an aqueous can coating, particularly a can outer surface coating, an initial or heat sterilization treatment of a can coating film (hereinafter referred to as "retort" or "retort treatment"). Even after the process, the processability, which is the required performance of the coating film,
TECHNICAL FIELD The present invention relates to a resin composition for water-based coatings, which provides adhesiveness, hardness and a good appearance.

[0002]

2. Description of the Related Art The outer surface of a beverage can containing soft drinks, etc. and a food can containing food etc. prevents corrosion of the can material, enhances aesthetic commercial value, and improves processability of the can and retort treatment process. It is formed by a coating film that can withstand.

Conventionally, these paints for the outer surface of a can have been prepared by dissolving an acrylic resin, a polyester resin, an epoxy resin and the like and a curing agent in an organic solvent. In recent years, however, many methods relating to the use of organic solvents such as the Fire Service Law have been prepared. Regulations have been tightened, and there has been a wide demand for water-based paints.

At present, as a paint for the outer surface of an aqueous can, an acrylic resin or a polyester resin is generally provided with an acidic group, which is neutralized with a volatile basic component, and then blended with an amino resin as a curing agent, and a slight organic solvent is used. A method is used in which an aqueous solution containing is coated with a roll coater or the like and baked and hardened in a baking furnace. The amino resin used at this time is an alkyl etherified methylol melamine resin (hereinafter referred to as melamine resin) which is a reaction product of melamine, formaldehyde and alcohol, or an alkyl etherified product which is a reaction product of benzoguanamine, formaldehyde and alcohol. Methylol benzoguanamine resin (hereinafter referred to as benzoguanamine resin) and the like are known.

The external coating for cans includes clear coating and white coating. Depending on the design of the can, clear coating alone or white coating / clear coating is applied.

[0006]

In the known resin for coating the outer surface of an aqueous can, a melamine resin or a benzoguanamine resin is used as a curing agent. Since the melamine resin involves a self-condensation reaction between the melamine resins during the crosslinking reaction, the flexibility of the physical properties of the coating film is likely to be impaired and the processability is disadvantageous.

Further, the benzoguanamine resin has a small self-condensation reaction, but has a small cross-linking reactivity with an acrylic resin used in combination at the same time. That is, the cured coating film has a drawback that the crosslink density is low and the hardness is insufficient.

The cured coating film on the outer surface of the can is required to have such properties as coating hardness against scratches during transportation, processing adhesion after retort treatment and appearance, and it is possible to improve such performance in a well-balanced manner. Will be needed.

As a result of extensive studies on the above problems, the present invention can provide a resin composition for water-based coatings, in which a cured coating film has good adhesion to processed parts, hardness and appearance even after retort treatment. .

[0010]

Means for Solving the Problems As a result of studying the above-mentioned problems, the present inventors have found that the resin composition for water-based paints containing a novel aminoformaldehyde resin has excellent adhesion to the processed part in the initial and retort treatment steps. It was found that a coating film having good hardness and appearance can be obtained, and the present invention was achieved.

That is, according to the present invention, norbornane diguanamine represented by the general formula 1 (chemical formula 3) and general formula 2 (chemical formula 4)
The addition reaction of an amino compound containing at least one selected from the group consisting of cyclohexanediguanamine as an essential component with formaldehyde, and 50 to 1% by weight of an amino resin (A) etherified with alcohol, and an acid value Aqueous resin (B) 50-9 having (solid content) 20-100 and hydroxyl value (solid content) 10-150
It is a resin composition for water-based paints, which comprises 9% by weight.

Embedded image (In the formula, 4,6-diamino-1,3,5-triazine-
The bonding position of the 2-yl group is 2,5- or 2,6-position)

Embedded image (In the formula, 4,6-diamino-1,3,5-triazine-
The bonding position of the 2-yl group is 1,2-1,3- or 1,4-
Indicate the position)

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The amino compound used in the present invention comprises the diguanamine compound represented by the above-mentioned general formula as an essential component. However, if necessary, melamine, benzoguanamine and acetoguanamine other than the diguanamine compound are contained. And other triazine compounds, urea, dicyandiamide, phenol, aniline and the like may be contained. The amount of the above-mentioned diguanamine compound used can be appropriately selected within a range that does not impair the significance of the present invention, but the higher the content of the diguanamine compound in the amino compound is, the more preferable, and the ratio in the amino compound is 50.
-100% by weight, preferably 80-100% by weight.

The amino resin (A) used in the present invention is
It is produced by reacting the diguanamine compound represented by the general formula with formalin and performing alkyl etherification with alcohol. The alcohols in this case include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, se.
c-butanol, tert-butanol, n-amyl alcohol, iso-amyl alcohol, tert-amyl alcohol, n-hexyl alcohol, sec-hexyl alcohol, 2-methylpentanol, 2-ethylbutyl alcohol, sec-heptyl alcohol, n-
Octyl alcohol, 2-ethylhexyl alcohol,
Examples of the ether alcohols include sec-octyl alcohol and cyclohexanol. For example, ethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monoisopropyl ether, and the like.
Examples of propylene glycol monobutyl ether and ketone alcohols include acetonylmethanol, diacetone alcohol, and pyruvyl alcohol.
The alcohol is used alone or in combination. Further, as the alkyl group, a methyl group is preferable from the viewpoint of making it aqueous. The amino resin (A) is used as a crosslinking agent in a solid content of 50 to 1% by weight, preferably 40 to 5% by weight.
If it exceeds 50% by weight, the processability of the coating film is poor and 1
If it is less than 5% by weight, the hardness and retortability of the coating film are poor.

The aqueous resin (B) used in the present invention has an acid value (solid content) of 20 to 100 that reacts with the amino resin (A).
And a water-soluble or water-dispersible resin having a hydroxyl value (solid content) of 10 to 150. Examples of such an aqueous resin (B) include water-soluble or water-dispersible acrylic resin, water-soluble or water-dispersible alkyd. Examples of the resin include water-soluble or water-dispersible acrylic resins. The water-soluble or water-dispersible acrylic resin is a polymer obtained by radical polymerization of at least one vinylic monomer, or a modified product thereof.

Examples of such vinylic monomers include (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid as the carboxyl group-containing vinylic monomer, and these may be used alone or in combination of two or more. You may use it. Examples of the hydroxyl group-containing vinylic monomer include hydroxymethyl (meth) acrylate, 2hydroxyethyl (meth) acrylate, and 2hydroxypropyl (meth).
Examples thereof include acrylate, hydroxybutyl (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate and the like. Further, as the non-functional vinyl monomer,
For example, methyl (meth) acrylate, ethyl (meth)
Acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, benzyl ( (Meth) acrylate, stearyl (meth) acrylate,
Isobornyl (meth) acrylate, phenoxyethyl (meth) acrylate, dimethylaminoethyl (meth)
Acrylate, glycidyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, diacetone acrylamide, Nn-butoxymethyl (meth) acrylamide, vinyl acetate, vinyl propionate, styrene, α-methylstyrene, vinyl Toluene and the like can be mentioned, and one kind or two or more kinds may be used in combination.

The mixture of the vinylic monomers becomes an aqueous resin (B) made of a polymer obtained by radical polymerization, and as the polymerization initiator, an organic peroxide type or an azo type is used. Examples of the peroxide type include benzoyl peroxide, t-butyl peroxy 2-ethylhexanoate, di-t-butyl peroxide, t-butyl peroxybenzoate and the like, and examples of the azo type include azobisisobutyronitrile and azo. Examples thereof include bisdimethylvaleronitrile.

Further, such an aqueous resin (B) is obtained mainly by solution polymerization, and a hydrophilic solvent is used as the solvent, for example, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether. , Ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and the like.

The water-soluble or water-dispersible alkyd resin is, for example, a polyvalent carboxylic acid, a polyhydric alcohol and optionally an oil, an alkyd resin obtained by reacting these fatty acids, and further modified products thereof. is there. As the polycarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid,
Tetrahydrophthalic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, norbornane-2,3-dicarboxylic acid, maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, trimellitic acid, Examples thereof include pyromellitic acid, methylcyclohexene tricarboxylic acid, paraoxybenzoic acid, dimethylolpropionic acid, oxypivalic acid, acid anhydrides thereof, and ester-forming precursors such as methyl ester. Polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol,
Propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6
-Hexanediol, 2,4-pentanediol, 2-
Ethyl-2-nbutyl-1,3-dihydroxypropane, tricyclodecanedimethanol, cyclohexane-
1,4-dimethanol, hydrogenated bisphenol, ε-caprolactone, trimethylene glycol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol and the like can be mentioned. Oils include, but are not limited to, tung oil, linseed oil, soybean oil, dehydrated castor oil, safflower oil, castor oil, coconut oil, tall oil and the like. Such an alkyd resin can be obtained by a known method, such as a method of reacting at 160 to 250 ° C. in the presence / absence of a transesterification catalyst.

The aqueous resin (B) synthesized as described above has an acid value of 20 to 100 in terms of solid content as an acid value for making it water-soluble or water-dispersible, and when it is less than 20, it is water-soluble or water-soluble. The dispersibility becomes difficult, and if it exceeds 100, the coating properties such as retort performance deteriorate. If the hydroxyl value, which is a heat-crosslinking component with the amino resin, is less than 10 or more than 150, the retort performance of the coating film is poor. The water-based resin (B) is used in the resin composition for water-based coatings in a solid content of 50 to 99% by weight, preferably 60 to 95% by weight, and 50% by weight.
If it is less than 99%, the retort performance of the coating film is poor, and if it exceeds 99% by weight, the hardness of the coating film is poor.

Upon forming the coating material, the acid value in the aqueous resin (B) is neutralized with a volatile base component such as ammonia or amine, and then mixed with the amino resin (A) and the like, and diluted with water to obtain an aqueous coating material. However, the volatile base component used for neutralization at this time is an amine, preferably a tertiary amine, such as monobutylamine, diethylamine, dibutylamine, monoethanolamine, diethanolamine, piperidine, triethanolamine, dimethylethanolamine, Diethyl ethanolamine, morpholine, etc. are mentioned, and they are further neutralized at a neutralization rate of 50 to 150%.

The aqueous resin composition of the present invention may contain an acid catalyst such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, or an acid catalyst amine block as a curing aid if necessary. Body etc. can be added. Further, conventionally known leveling agents, defoaming agents, lubricants, pigments and the like can be added to the resin composition for water-based paints by dispersing, mixing or the like.

As a method for coating the resin composition for water-based paint of the present invention, known means such as roll coating, spraying, brush coating can be used. According to the resin composition for an aqueous paint of the present invention, the adhesion of the processed portion after retort treatment, which is a drawback of the coating film of the conventional coating, the hardness, the appearance and the like are good, and the hardness and the appearance of the initial coating film are also excellent. A well-balanced coating film can be obtained.

[0023]

EXAMPLES In order to more specifically describe the present invention,
The present invention will be described with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples,% means% by weight, and part means part by weight.

Reference Example 1 Production of norbornane diguanamine: 500 m equipped with a stirrer, a thermometer, a liquid introducing tube, and a cooler
l In a flask, add bicyclo [2.2.1] hepter-5-ene-2.
-Carbonitrile 297.92 g (2.50 mol), Ni [P (OC ₆ H ₅ ).
₃ ] ₄ 8.77 g (6.75 mmol), ZnCl ₂ 4.80 g (35.22 mmol), P (OC ₆ H ₅ ) ₃ 32.27 g (0.104 mol) were charged, and the system was sufficiently replaced with nitrogen gas, and then stirred. The reaction mixture was kept at 55 ° C. Next, 94.59 g (3.50 g
Mol) was supplied to the reactor at a flow rate of 45 to 55 ml / hr for 3 hours, and then the reaction was further performed for 1 hour. Further, the system was replaced with nitrogen gas, deionized water was added, and the aqueous layer was separated and removed to obtain a semi-solid oily substance. The oil was filtered and distilled under reduced pressure to give 362.20 g of bicyclo [2.2.1] heptane-2,5-dicarbonitrile and bicyclo [2.2.1].
A mixture of heptane-2,6-dicarbonitrile (boiling point 1
Dicarbonitrile consisting of 29-137 ° C / 1 mmHg) was obtained.
Next, 146.2 g (1.0 mol) of this dicarbonitrile, 210.2 g (2.5 mol) of dicyandiamide, 16.8 g of caustic potash, and 1000 ml of methyl cellosolve were placed in a 3 L flask equipped with a stirrer, a thermometer, and a reflux condenser, and gradually heated. did. The reaction was carried out for 10 hours while stirring this solution at a temperature of 120 to 125 ° C.

After removing the solvent from this reaction mixture, 3
L of deionized water was poured, the deposited white precipitate was filtered off, and the solid content was washed with deionized water and methanol and dried under reduced pressure. Furthermore, this solid content is dissolved in ethyl cellosolve,
Deionized water was added to this solution for reprecipitation and then filtered off, and the solid content was washed with water. The solid content was dried under reduced pressure to give 2,5-bis (4,
6-diamino-1,3,5-triazin-2-yl) -bicyclo [2.2.1] heptane and 2,6-bis (4,6-diamino-1,3,
Norbornane diguanamine consisting of a mixture of 5-triazin-2-yl) -bicyclo [2.2.1] heptane [melting point 317-324 ° C (DSC measurement)] was obtained.

Reference Example 2 Production of cyclohexanediguanamine: A stirrer, a thermometer, a gas introduction tube, and a cooler were attached.
In a 500 ml flask, 4-cyano-cyclohexene 188.6
g, Ni [P (OC ₆ H ₅ ) ₃ ] ₄ 6.0 g, ZnCl ₂ 3.0 g, P (OC ₆ H ₅ ) ₃ 2
After charging 3.9 g and sufficiently replacing the inside of the system with nitrogen gas, the reaction mixture was kept at 75 ° C. with stirring. Next, 42 mol% concentration of hydrogen cyanide gas diluted with nitrogen was supplied to the reactor at a rate of 177.0 mmol / hour for 7 hours. Further, after purging the system with nitrogen gas, 500 g of water and 500 g of ethyl acetate were added to the reaction solution, and the mixture was left under stirring for 5 hours. Then, the organic layer was separated, and ethyl acetate was evaporated and distilled off. . Next, vacuum distillation was carried out to obtain a dicarbohydrate consisting of a mixture of 132.0 g of 1,3-cyclohexanedicarbonitrile and 1,4-cyclohexanedicarbonitrile as a fraction having a pressure of 0.5 to 1.0 mmHg and a temperature of 120 to 130 ° C. The nitrile was obtained. Next, 134.2 g (1.0 mol) of this dicarbonitrile, 210.2 g (2.5 mol) of dicyandiamide, 16.8 g of caustic potash, and 1000 ml of methyl cellosolve were placed in a 3 L flask equipped with a stirrer, a thermometer, and a reflux condenser, and gradually heated. did. The reaction was carried out for 10 hours while stirring this solution at a temperature of 120 to 125 ° C.

After removing the solvent from this reaction mixture, 3
L of deionized water was poured, the deposited white precipitate was filtered off, and the solid content was washed with deionized water and methanol and dried under reduced pressure. Furthermore, this solid content is dissolved in ethyl cellosolve,
Deionized water was added to this solution for reprecipitation and then filtered off, and the solid content was washed with water. This solid content was dried under reduced pressure to give 1,3-bis (4,
A mixture of 6-diamino-1,3,5-triazin-2-yl) -cyclohexane and 1,4-bis (4,6-diamino-1,3,5-triazin-2-yl) -cyclohexane [melting point 317 ~ 321
C. (DSC measurement)] was obtained.

Production Example 1 Synthesis of amino resin: 314 parts by weight of norbornane diguanamine obtained by the method of Reference Example 1 in a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a solvent by-product recovery device. , 640 parts by weight of methanol and 391 parts by weight of paraformaldehyde (containing 92% of formaldehyde) were added, and the mixture was stirred for 20 times.
% Caustic soda was added to adjust the pH of the reaction solution to 11.
Then, it heated and maintained the reaction material at 50 degreeC, and continued reaction for 30 minutes. Next, the pH of the reaction solution was adjusted to 3 with a 20% aqueous nitric acid solution, and the reaction was continued at 45 ° C. for 6 hours. The reaction mixture was adjusted to pH 8 and the heating residue of the resin (JISK-54
(According to the measuring method of 00) was concentrated to 80% by weight.
The viscosity of the norbornane diguanamine resin obtained at this time was 5 poise (20 ° C.).

Production Example 2 Synthesis of amino resin: 314 parts by weight of norbornanediguanamine obtained by the method of Reference Example 1, 900 parts by weight of isopropanol, paraformaldehyde (80% formaldehyde) were added to the reactor used in Production Example 1.
After containing 188 parts by weight, 2 with stirring.
The pH of the reaction solution was adjusted to 9 by adding 0% caustic soda.
Then, it heated and kept the reaction material under reflux, and continued the reaction for 60 minutes. Next, the pH of the reaction solution was adjusted to 5 with a 20% aqueous nitric acid solution, and the reaction was continued under reflux for 3 hours. The reaction mixture was adjusted to pH 8 and the heating residue of the resin (JISK-54
(According to the measuring method of 00) was concentrated to 60% by weight.
The viscosity of the norbornane diguanamine resin obtained at this time was 30 poise (20 ° C.).

Production Example 3 Synthesis of amino resin: 302 parts by weight of cyclohexanediguanamine obtained by the method of Reference Example 2 was used instead of 314 parts by weight of norbornane diguanamine obtained by the method of Reference Example 1 in Production Example 1. The reaction and adjustment treatment were carried out in the same procedure as in Production Example 1 except that it was used. The pH of this reaction mixture was adjusted to 8, and the heating residue of the resin (according to the measuring method of JIS K-5400) was concentrated to 80% by weight. The viscosity of the cyclohexane diguanamine resin obtained at this time was 6 poise (20 ° C.).

Production Examples 4 to 7 Synthesis of Aqueous Resin: Thermometer,
After charging 68.7 parts by weight of butyl cellosolve to a four-necked flask equipped with a stirrer, a reflux condenser, a dropping tank, and a nitrogen gas introduction tube, the temperature was raised to 140 ° C., and the polymerizable unit amount shown in Table 1 was used. The mixture of the body component (part by weight) and the catalyst (part by weight) was subjected to dropwise polymerization over 5 hours. Also, the acid value (solid content) and hydroxyl value (solid content) of each aqueous resin obtained above
Is shown in Table 1.

[0032]

[Table 1] (Note 1) Indicates the composition of polymerizable monomer components (parts by weight).

Production Example 8 Synthesis of Aqueous Resin: 227 parts by weight of isophthalic acid and 83 parts by weight of hexahydrophthalic acid were placed in a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen gas inlet tube and a water separator. Parts, adipic acid 143 parts by weight, 1,6-hexanediol 70 parts by weight, cyclohexane-1,4-dimethanol 71 parts by weight, neopentyl glycol 21 parts by weight, trimethylolpropane 328.
After charging parts by weight, the temperature was gradually raised and the reaction was carried out at an internal temperature of 220 ° C. After the reaction mixture was reacted until the acid value (solid content) became 3, 57 parts by weight of trimellitic anhydride was added. This is heated at an internal temperature of 170 ° C to obtain an acid value (solid content)
The reaction was carried out until it reached 47. The hydroxyl value (solid content) of the obtained resin was 146. Then, the solvent butyl cellosolve was added to this resin to obtain an alkyd resin solution having a solid content of 60% by weight.

Examples 1 to 5 Amino resins obtained in the above Production Examples 1 to 3 and Production Example 4
As shown in Table 2, the water-based resin obtained in Example 1 was used for a white coat, and the resin composition for water-based coatings A to A of the present invention was used.
E was compounded and prepared. Then, using these, a test coat for white coat was prepared by the method of Test Example 1, and the coat was evaluated.

Comparative Examples 1 to 5 Amino resins obtained in Production Example 1 and Production Examples 4 to 7
As shown in Table 2, using the aqueous resin obtained in Example 1, a resin composition F for aqueous coating composition of Comparative Example for white coat was used.
J was compounded and prepared. Next, using these, the test coating film was prepared and the coating film was evaluated in the same manner as in Examples 1 to 5. next,
Table-3 shows the evaluation results of the white coat coating films of Examples 1 to 5 and Comparative Examples 1 to 5.

[0036]

[Table 2]

(Test Example 1: Preparation of Test Coating Film for White Coat) Resin Compositions A to J for Aqueous Coating Compositions in Table 2 above
Was coated on a tin plate with a thickness of 0.3 mm with a bar coater to a film thickness of about 10 μm when dried.
A test piece was prepared by baking at 00 ° C for 30 seconds. As the coating film performance of the obtained test piece, an initial hardness and retort performance test were conducted, and the paint stability as a resin composition for water-based paint is also shown in Table 3 below. The test method and the judgment method are shown below.

(Paint Stability) Each of the resin compositions for water-based paints was placed in a test tube and kept at a constant temperature (20 ° C.) for 7 days,
The presence or absence of separation in 30 days) was observed. ◯: No change Δ: Slightly separated (5% or less of the whole) X: Separated (5% or more of the whole) (Film hardness test) The initial hardness of the paint film is the pencil hardness (JIS).
K5401).

(Retort Performance Test: Appearance) The test piece was put in a high temperature high pressure sterilizer containing a fixed amount of ion-exchanged water.
After 30 ° C. × 30 minutes, the appearance of the taken-out test piece was observed. ◯: Good Δ: Slightly poor (slightly delustered or with traces) ×: Poor (lustre or blister and traces)

(Retort Performance Test: Adhesion to Processed Area) A test piece previously processed by a DuPont impactor or Erichsen tester was put in a high temperature and high pressure sterilizer and heated at 130 ° C. × 3.
Take out after 0 minutes, peel off the processed part of the test piece with tape,
The peeling and cracking of the coating film were observed. ○: Good ◇: Semi-good (slight cracking) △: Somewhat bad (slightly peeled) ×: Bad (peeled)

[0041]

[Table 3]

As shown in Table 3, the water-based coating compositions prepared in Examples 1 to 5 have excellent retort properties (appearance, adhesion to the processed part) of the coating film, good hardness, and good balance. It was found that the film had a sharp coating. On the other hand, it was found that the water-based coating compositions prepared in Comparative Examples 1 to 5 were particularly inferior in retortability (appearance, adhesion of processed part).

Examples 6 to 15 Using the amino resin obtained in the above Production Example 1 and the aqueous resin obtained in Production Example 4, as shown in Table 2, for clear coating, the water-based paint of the present invention was used. A resin composition K was blended and prepared. Then, using this, a test coating film for clear coat was prepared by the method of Test Example 2 and the coating film was evaluated.

Comparative Examples 6 to 15 Using the amino resin obtained in Production Example 1 and the aqueous resin obtained in Production Example 5, as shown in Table 2, for clear coating, the aqueous coating composition of Comparative Example was used. A resin composition L was blended and prepared. Next, using this, the test coating film was prepared and the coating film was evaluated in the same manner as in Examples 6 to 15. Next, Example 6
.About.15 and Comparative Examples 6 to 15 show the evaluation results of clear coat coating films in Table-4.

(Test Example 2: Preparation of Test Coating Film for Clear Coat) Using the resin compositions A to J for water-based paint shown in Table 2 above, white coat coating test pieces were prepared by the method of Test Example 1. . Next, on this white coat test piece,
Each of the resin composition K for water-based paints of the present invention or the resin composition L for water-based paints of the comparative examples shown in Table 2 was applied by a bar coater to a dry film thickness of 15 μm, and then applied. The plate was baked at a temperature of 200 ° C. for 30 seconds to prepare a test piece. The coating film performance of the obtained test piece is shown in Table 4 by conducting a coating film hardness and retort performance test in the same manner as in Test Example 1 and adding a hardness test in hot water to observe the hardness when a temperature is applied. The test method and determination method are the same as in Test Example 1, but the in-water hardness test method is shown below.

(Hot Water Hardness Test) The test piece was immersed in warm water of 80 ° C., and after 5 minutes, the pencil hardness (JIS K540
1) was measured.

[0047]

[Table 4]

As shown in Table 4, the coating film obtained from the resin composition for a water-based coating composition of the present invention for clear coating was used for the water-based coating composition of Comparative Example in hardness and retortability on any white coat. It was found to be better and better than the coating film obtained from the resin composition. The comparative example was found to be particularly inferior in hot water hardness and retortability. Furthermore,
When the resin composition for an aqueous paint of the present invention was used for both white coat and clear coat, the coating film physical properties and the balance of physical properties were remarkably excellent.

Example 16 30.4 parts by weight of the amino resin (solid content) obtained in Production Example 1 and the alkyd resin (solid content) obtained in Production Example 8 69.
6 parts by weight, neutralizing agent dimethylethanolamine 9.0 parts by weight, catalyst trade name "CARISTO 6000" [manufactured by Mitsui Toatsu Chemicals, Inc.] 0.5 parts by weight, pigment titanium dioxide 100 parts by weight and deionized water. A resin composition for an aqueous coating material for a white coat having a compounding ratio of 200 parts by weight was compounded and adjusted.
Then, using this, a test coating film for white coat was prepared in the same manner as in Example 1. Using this test coating film, coating film evaluation was carried out in the same manner as in Example 1, and the results were: paint stability (7 days, 30 days) ◯ (no change), retort appearance ◯ (good), processed part adhesion The resin composition for a water-based coating composition of the present invention provided an excellent coating film.

[0050]

As described above, the resin composition for water-based paints of the present invention has good water solubility or water dispersibility in white coat applications and clear coats, and has a coating film hardness (hardness in hot water). Each coating film performance such as retort property (appearance, adhesion of processed portion) is also good, and a well-balanced and good coating film can be provided.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryunobu Nakajima 1900 Togo, Mobara-shi, Chiba Mitsui Toatsu Chemical Co., Ltd.

Claims (3)

[Claims] 1. An amino compound containing, as an essential component, at least one selected from the group consisting of norbornane diguanamine represented by the general formula 1 (Formula 1) and cyclohexane diguanamine represented by the general formula 2 (Formula 2). Of 50 to 1% by weight of amino resin (A) etherified with alcohol and formaldehyde, and acid value (solid content) 20 to 100 and hydroxyl value (solid content) 10 to 15
A resin composition for an aqueous coating material, which comprises 50 to 99% by weight of an aqueous resin (B) which is 0. Embedded image (In the formula, 4,6-diamino-1,3,5-triazine-
The bonding position of the 2-yl group is 2,5- or 2,6-position) (In the formula, 4,6-diamino-1,3,5-triazine-
The bonding position of the 2-yl group is 1,2-1,3- or 1,4-
Indicate the position) 2. The resin composition for an aqueous paint according to claim 1, wherein the aqueous resin (B) is an acrylic resin. 3. The resin composition for an aqueous coating composition according to claim 1, wherein the aqueous resin (B) is an alkyd resin.