JP2741382B2 - Metal surface coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a metal surface coating agent,
The present invention relates to a coating agent which exhibits excellent cleaning effect, rust prevention and polishing effect when used on a metal surface, for example, a car body such as an automobile. When the coating agent is applied to a metal surface, it cleans the metal surface and, at the same time, forms an easily peelable coating film having excellent water resistance and detergent resistance on the metal surface.

[Conventional technology]

As the coating agent having the cleaning effect, the rust prevention effect and the polishing effect on the metal surface, those having the composition shown in Table 1 are conventionally used.

Solvent-type coating agents (coating agents that do not use water as a solvent) generally contain non-oxidized wax and silicone oil, and do not contain surfactants and aqueous components. Such solvent-based coatings are excellent in water resistance and detergent resistance, but are inferior in the ability to remove contaminated coatings after being used for a long period of time. Problems also arise.

On the other hand, an aqueous (emulsifier) coating agent forms a W / O or O / W type emulsion because it contains an oxidized wax and a surfactant. The oxidized wax is neutralized with an alkali metal, an amine or the like, and further emulsified in water or a solvent with a surfactant or the like. Such an aqueous coating agent is washed while uniformly applying the coating agent to a metal surface, then evaporating water and a solvent, buffing to form a smooth and uniform coating, and polishing. Used. However, the formed film still contains hydrophilic groups such as alkali salts and amine salts of oxidized wax, as well as a surfactant, and the film does not have sufficient water resistance and detergent resistance. Further, the rust-preventing effect is also reduced by the alkali agent, amine and the like remaining in the coating. Therefore, conventional aqueous coating agents cannot be said to be coating agents.

Silicon oil has excellent water repellency and polishing effect, but has poor compatibility with oxidized wax. Therefore, in the applied film, the silicon oil is present in a state of being dispersed or separated in the oxidized wax, and the surface of the coating material promotes sticky stains depending on the usage.

In addition, the oxidized wax coating with poor detergent resistance and water resistance,
It was removed from the metal surface during cleaning together with the silicone oil in the coating agent, and sufficient durability could not be obtained.

Therefore, it is conceivable to use a coating agent which is excellent in detergent resistance and water resistance and which is obtained by mixing silicone oil with non-oxidized wax. However, such a coating agent is difficult to remove chemically after long-term use and contamination, and must be physically polished or removed by dissolving the coating with a solvent. However, the use of an abrasive or a solvent has the disadvantage that the metal surface and the painted surface are damaged.

[Problems to be solved by the invention]

Therefore, an object of the present invention is excellent in detergent resistance and water resistance,
An object of the present invention is to provide an aqueous coating agent for a metal surface having a non-sticky coating surface and being chemically peelable.

[Means for solving the problem]

The present invention relates to a higher fatty acid-modified silicone oil, a carnauba-containing silicone oil, a higher fatty acid-containing silicone oil, an epoxy-modified silicone oil, a mercapto-modified silicone oil, an amino-modified silicone oil, a fluorine-modified silicone oil, an alcohol-modified silicone oil and a polyether-modified silicone. The present invention relates to a metal surface coating agent containing a silicone oil, an oxidized wax, a silicone oil, a polyvalent metal complex and water selected from the group consisting of oils.

 Hereinafter, the present invention will be described.

The oxidized wax used in the present invention is a wax having a carboxyl group, and a part or all of the carboxyl group may form a salt. Examples of the oxidized wax include carnauba wax, montan wax, candelilla wax, Fischer-Tropsch wax, polyethylene oxide wax and the like. In addition, examples of the cation that forms a salt include an ammonium ion, an alkali metal ion, and an amine ion.

In the present invention, a silicone oil having a carboxyl group is used, and any silicone oil having a free carboxyl group in the molecule can be used. For example, higher fatty acid modified silicone oil, carnauba-containing silicone oil, higher fatty acid-containing silicone oil, epoxy-modified silicone oil, mercapto-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, alcohol-modified silicone oil, polyether-modified silicone oil, etc. Can be used. Further, the carboxyl group in the silicone oil may partially or entirely form a salt, and as a cation forming a salt,
For example, ammonium ion, alkali metal ion, amine ion and the like can be mentioned.

The amount of the carboxyl group and / or its salt in the oxidized wax and the silicone oil can be expressed as an acid value.

In the present invention, the acid value of the oxidized wax is suitably from 2 to 200, preferably from 30 to 130 per wax solid content. The acid value of the silicone oil is suitably 2 to 100, preferably 10 to 50, based on the solid content of the silicone oil. When the acid value of the oxidized wax and the silicone oil is higher than the above range, the releasability is good, but the water resistance and the detergent resistance tend to decrease. When the oxidation is lower than the above range, the water resistance and the detergent resistance are good, but the peelability tends to be low.

Here, the acid value is the number of mg of KOH per 1 g of solid content.

The polyvalent metal in the polyvalent metal complex compound used in the present invention is a divalent or higher valent metal, such as calcium, magnesium, zinc, barium, aluminum, zirconium, nickel, iron, cadmium, strontium, bismuth, and beryllium. , Cobalt, lead, copper and antimony can be used. Particularly preferred are calcium, zinc and aluminum.

Examples of the ligand for forming the polyvalent metal complex include a carbonate ion, an acetate ion, a malate ion, an oxalate ion, a vidroxy acetate ion, a tartrate ion, an acrylate ion, a lactate ion, an octoate ion, and a formate ion. , Salicylate, benzoate, gluconate and glutamate, glycine, alanine, ammonia, morpholine, ethylenediamine, dimethylaminoethanol, diethylaminoethanol, monoethanolamine, diethanolamine, triethanolamine or similar inorganic acids, organic Acids, amino acids,
An amine or the like can be used.

Examples of the polyvalent metal complex capable of exhibiting preferable performance in the present invention include, for example, zinc carbonate ammonium, calcium carbonate ammonia-ethylenediamine, zinc acetate, zinc ammonium acrylate, zinc ammonia malate, zirconium ammonium carbonate, aminoacetic acid Zinc ammonia, alanine calcium ammonia, and the like.

Zinc ammonium carbonate (NH ₄ ) ₄ ZnCO ₃ Calcium ethylenediamine carbonate (NH ₂ CH ₂ CH ₃ NH ₂ ) CaCO ₃ Zinc ammonium acetate (NH ₄ ) ₄ Zn (CH ₃ COO) ₂ Zinc ammonium acrylate (NH ₄ ) ₄ Zn (CH ₂ CHCOO) ₂ Ammonia zinc malate (NH ₄ ) ₄ ZnCH ₂ COO.CHOH.COO Ammonia zirconium carbonate (NH ₄ ) ₂ [Zr (OH) ₂ (CO ₃ ) ₂ ] Zinc ammonia amino acetate (NH ₄ ) ₄ Zn (NH ₂ CH ₂ COO) ₂ Alanine calcium ammonia (NH ₄ ) ₄ Zn (CH ₃ CHNH ₂ COO) ₂ The coating agent of the present invention has a total of 50% in total of the oxidized wax and the silicon oil having a carboxyl group. %, Preferably 0.5 to 20%, more preferably 3 to 10%. The weight ratio of the oxidized wax to the silicone oil having a carboxyl group is 5 to 95:95 to 5, preferably 30 to 60:
Suitably it is between 70 and 40.

Further, the polyvalent metal complex has an oxygen content of 0.
It is preferred that it be used to contain from 0.5 to 1.0, preferably from 0.1 to 0.5, stoichiometric equivalents of polyvalent metal.

If necessary, an emulsion of an acrylic resin, a styrene resin, or a styrene-acrylic copolymer resin can be added to the coating agent of the present invention.

Further, various additives can be added to the coating agent of the present invention, if desired. For example, an alkali-soluble resin, a soft abrasive which does not damage the material, a solvent having low solubility, and the like can be used.

When the minimum film formation temperature of the composition of the present invention is equal to or higher than room temperature, a coalescing agent and a plasticizer can be added to enable formation of a film at room temperature. However, when a film can be formed at room temperature, it is not necessary to use these coalescing agents and plasticizers.

The coating agent of the present invention is prepared by adding a prescribed amount of a polyvalent metal complex to an aqueous (emulsified) composition comprising an oxidized wax, a silicon oil having a carboxyl group, and water, for example, at normal temperature and normal humidity under stirring and mixing. Thus, it can be manufactured.

The polyvalent metal in the present invention is used as a complex. When a polyvalent metal that does not form a complex, for example, a hydroxide of a polyvalent metal, is added to an aqueous emulsion composition containing a carboxylic acid, a carboxyl group and / or a salt thereof is cross-linked by the polyvalent metal. And various problems arise. For example, the obtained aqueous coating composition becomes difficult to be stably emulsified or dissolved, increases in viscosity with the passage of time, deteriorates the work at the time of application, and deteriorates the finished state.
Furthermore, since the temperature required for film formation (minimum film formation temperature) also increases, a continuous film cannot be obtained when applied at a low temperature. For this reason, adhesion to a metal surface, gloss, water resistance, detergent resistance, durability, and leveling properties are poor.

On the other hand, in the composition of the present invention, by containing a polyvalent metal used as a metal crosslinking agent as a polyvalent metal complex, the aqueous emulsion composition can be present in a state of extremely excellent stability. Since the polyvalent metal forms a complex, a crosslinking reaction between the carboxyl groups due to the polyvalent metal does not occur, and the composition of the present invention is stable without a change in viscosity.

When the coating agent of the present invention is applied to a metal surface, two or more carboxyl groups in an aqueous emulsion component (oxidized wax and silicone oil) are crosslinked by the action of a polyvalent metal ion due to evaporation of volatile components such as water. , Forming a tough film. The resulting film has excellent water resistance, detergent resistance, toughness and peelability, and is not attacked by neutral detergents or weak alkaline detergents. However, when a detergent containing chelating ammonia water, amines, etc. is applied, the polyvalent metal which has cross-linked the carboxyl group is easily removed to form an alkali agent and a carboxylate contained in the detergent. , And can be easily peeled without using a mechanical polishing method.

The detergent (stripping agent) that can be used to strip the film formed by the coating agent of the present invention is an alkali solution containing a ligand. Here, examples of the ligand include ethylenediaminetetraacetic acid, N-hydroxyethylenediamine-N, N ', N'-triacetic acid, ammonia, monoethanolamine, and morpholine. Also, the alkaline solution is
Examples of the alkaline substance include sodium hydroxide, potassium hydroxide, sodium metasilicate, and the like.

Further, the alkaline solution containing the above ligand can contain a surfactant. The addition of a surfactant is preferred because it tends to increase the adhesion and dispersibility of the aqueous emulsion composition.

 Production examples of the coating agent of the present invention are shown below.

Production Examples 1 to 3 A wax, silicon, an emulsifier, and a solvent shown in Table 2 were added to a production kettle equipped with a stirrer, a heating device, a thermometer, and a cooling device, and heated until all were melted. After complete dissolution,
A prescribed amount of morpholine is added and reacted with oxidized wax, silicon oxide and the like. Boil water to 90-100 ° C in a separate container. While stirring, boiling water is gradually added into the production kettle to emulsify. After pouring boiling water, it is cooled immediately to obtain the coating agent of the present invention.

Production Examples, Examples, and the `` active ingredient '' in Comparative Examples,
The content (concentration) of each component is shown, and its unit is% by weight.

 Hereinafter, an example of the present invention will be described in more detail.

Example Coating agent samples No. 1 to No.
Sample No. 13 was prepared, and the applicability, gloss, water resistance, detergent resistance, outflow, peelability and durability of each sample were evaluated by the following methods. Table 4 shows the results.

1.Applicability On a black epoxy coating on an aluminum plate, apply a sample to 10 ± 2 per square meter. After drying at room temperature for 1 hour, the film is rubbed five times with a uniform force with a cotton cloth to form a uniform film, and the buffing property and leveling property at that time are visually evaluated.

2. Glossiness The gloss of the test specimen applied in accordance with the method of the applicability test is measured. The gloss measurement device is performed according to JIS-Z8741.
Note that the incident angle is 60 degrees.

3. Water resistance The test specimen applied according to the method of the applicability test is allowed to stand at room temperature at a relative humidity of 80% or less for 24 hours. Test specimen at 23 ± 10 ℃
Rest on the horizontal fixed base of, drop 0.1 distilled water,
After covering with a cover glass and allowing to stand for 30 minutes, water is absorbed and left for 1 hour, and the whitening state is visually measured.

4. Detergent Resistance The test specimen applied according to the method of application test is 28 ± 2.
Leave in a thermostat at 18 ° C for 18 hours. After washing, using a washing solution (pH 9.0 ± 0.2) prepared by dissolving 0.1 g of sodium dodecylbenzenesulfonate in 200 distilled water, immerse a pig hair brush of Gardner Straight Line Washability Tester in the detergent solution for 2 minutes. Thereafter, pour 10 ± 2 over the test and start the test immediately. After 10 reciprocations, the test pieces are rinsed with clear water, air-dried and evaluated.

5. Outflow properties Test specimens applied according to the test method for coatability test should be 60 ± 5
The flowability of the coating applied to the test piece was visually evaluated by inclining at 30 ° in a thermostat at ℃.

6. Peelability The test piece applied according to the method of the applicability test is 28 ± 2
Leave in a thermostat at 24 ° C for 24 hours. The stripping solution used was a stripping solution (pH 11.0 ± 0.2) prepared by dissolving 0.1 g of sodium dodecylbenzenesulfonate, 0.2 g of 4-sodium ethylenediaminetetraacetate and 0.2 g of monoethanolamine in 200 distilled water.・ After immersing the pig brush of the washability tester in the stripper for 2 minutes,
Pour ± 2 on the test and start the test immediately. After 20 reciprocations, the test pieces are rinsed with clear water, air-dried and evaluated.

7. Durability The overall performance is evaluated from the performance such as water resistance, abrasion resistance and gloss reduction over time.

(1) Hoechst Wax U, acid value 78-88, manufactured by Hoechst AG of West Germany (2) AC-540, manufactured by Allied Chemical Company, USA
Acid value 40 (3) Shin-Etsu Chemical Co., Ltd. X-22-3701E Oxidation 14.7
(Silicone oil containing carnauba) (4) Nippon Oil Co., Ltd., brand name: New Solder Deluxe (5) Sanyo Kasei Kogyo Co., Ltd., brand name: Nonipol 100 (6) Kao Corporation, brand name: Leodor AO-10 (7) ) Shin-Etsu Chemical Co., Ltd., KF-96 (350cs) (8) Shin-Etsu Chemical Co., Ltd., KF-857 (9) Johns Manville, USA
oss (10) Aqueous zinc carbonate solution 54.0 g of water was placed in a container equipped with a stirrer, and 10 g of zinc oxide was gradually added with stirring to disperse the zinc oxide in the water. Next, 18 g of 28% ammonia water and 18 g of ammonia carbonate were sequentially added, and stirring was continued until the mixture was dissolved to obtain an aqueous solution of zinc carbonate ammonium. (Containing 8.03% as zinc).

(11) Ammonia zirconium carbonate aqueous solution Made by Shin Nippon Metal Chemical Co., Ltd. Zirconium ammonium carbonate ZrO ₂ 13%, pH 8.40 Specific gravity (20 ℃) 1.235 (Contains 9.63% as zirconium) (12) Aqueous zinc acetate aqueous solution In a container with a stirrer Add 55 g of water, gradually add 15 g of zinc acetate with stirring, and disperse zinc acetate in water.
Add 30 g of ammonia water, continue stirring until dissolved,
An aqueous solution of zinc acetate ammonia was obtained (containing 8.03% as zinc).

(13) Aqueous solution of zinc ammonium acetate aqueous solution In a container equipped with a stirrer, add 47.9 g of water, add 10.0 g of zinc oxide to the water with stirring, disperse the mixture, add 23.6 g of 28% aqueous ammonia, and add 18.5 g of aminoacetic acid. In addition, the mixture was stirred until the solution became homogeneous to obtain an aqueous solution of ammonium aminoacetate ammonium (containing 8.03% as zinc).

(14) Aqueous zinc malate solution In a container equipped with a stirrer, add 43.5 g of water, add 10.0 g of zinc oxide to the water while stirring, disperse, and then dissolve 16.5 g of malic acid.
To make zinc malate, 28% ammonia water 30.0%
g was added thereto, and the mixture was stirred until the solution became homogeneous to obtain an aqueous solution of zinc malate ammonium. (Containing 8.03% as zinc).

[Effect of the Invention] A film formed using the coating agent of the present invention has detergent resistance,
It has excellent water resistance and can be easily peeled off chemically.

Claims (4)

(57) [Claims] 1. Higher fatty acid modified silicone oil, carnauba-containing silicone oil, higher fatty acid-containing silicone oil, epoxy-modified silicone oil, mercapto-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, alcohol-modified silicone oil and polyether-modified A metal surface coating agent containing silicon oil, oxidized wax, polyvalent metal complex and water selected from the group consisting of silicon oil. 2. The metal surface coating agent according to claim 1, wherein the silicone oil and the oxidized wax are present in an emulsified state. 3. The metal surface coating agent according to claim 1, wherein a part or all of the carboxyl groups contained in the silicone oil and the oxidized wax form a salt. 4. The coating agent for a metal surface according to claim 1, further comprising a surfactant.