JPH0619068B2 - Aluminum paste composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum paste for ship bottom paints, which has a significantly improved coating adhesion.

It is well known that the No. 1 paint on the bottom of the boat containing aluminum paste is effective for preventing corrosion of the hull that is constantly immersed in seawater containing salt and exposed to a severe corrosive environment. Conventionally, a non-leafing type aluminum paste containing an unsaturated fatty acid (for example, oleic acid) has been used as the aluminum paste for the ship bottom No. 1 paint.

On the other hand, when applying the No. 1 paint on the bottom of the ship, a wash primer for long-term exposure containing polyvinyl butyral, zinc chromate, and phosphoric acid as main components is used to prevent corrosion on the outfitting platform.

When a non-leafing type aluminum paste containing unsaturated fatty acids was used as the aluminum paste for ship bottom No. 1 paint, the adhesion to the wash primer for long-term exposure was poor and peeling occurred at the interface with the wash primer during voyage. The drawback of causing a phenomenon has been pointed out for some time. Not only was it poor in adhesion to other shop primers, such as organic or inorganic zinc rich primers.

On the other hand, when a leafing type aluminum paste containing saturated fatty acid (eg stearic acid) was used as the aluminum paste for ship bottom No. 1 paint, not only the peeling phenomenon at the interface with the shop primer was observed, but also the ship bottom.
Due to poor wettability with the chlorinated rubber resin mainly used for No. 1 paint, pseudo-destructive phenomenon was observed in the paint film layer of No. 1 paint on the ship bottom.

As a result of earnest research to solve the above-mentioned difficulties of the prior art, the present inventor has found that the surface of each aluminum powder has 12 carbon atoms.
Adsorbs both one or more fatty acids selected from linear saturated fatty acids of ~ 22 and one or more fatty acids selected from unsaturated fatty acids of 16 to 22 carbon atoms (monoenoic acid, dienoic acid and trienoic acid). It has been found that the aluminum paste composition being used is effective for improving the coating adhesion of the ship bottom paint,
The present invention has been reached.

In a method of producing an aluminum paste by a dry grinding method in a nitrogen atmosphere containing an aluminum starting material and a fatty acid or a wet grinding method in an organic solvent, a carbon number of 12 is used as a grinding aid.
The aluminum paste composition obtained by using one or more linear saturated fatty acids of 1 to 22 and one or more unsaturated fatty acids of 16 to 22 carbons has good adhesion when used in the ship bottom 1 paint coating. It was a finding.

Further, the above fatty acid composition is effective even if added and mixed in the kneading stage after pulverization. In the kneading step, a conventional leafing type aluminum paste crushed in the presence of saturated fatty acid may be added with an unsaturated fatty acid, or in the kneading step of a non-leafing type aluminum paste crushed in the presence of an unsaturated fatty acid. Even the bottom of a ship by adding saturated fatty acids 1
An aluminum paste composition effective for improving the adhesion of the paint film is obtained.

That is, in the present invention, as a final product, a straight chain saturated fatty acid having 12 to 22 carbon atoms is selected on the surface of each aluminum powder.
Both of one or more fatty acids and one or more fatty acids selected from unsaturated fatty acids having 16 to 22 carbon atoms in a saturated fatty acid / unsaturated fatty acid content ratio of 9/1 to 1/9, The present invention relates to an aluminum paste composition containing 7.0 parts by weight or less of 100 parts by weight of aluminum powder as the total amount of fatty acids.

Examples of straight chain saturated fatty acids having 12 to 22 carbon atoms in the present invention are as follows: lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid.

Examples of unsaturated fatty acids include zomarinic acid, oleic acid, elaidic acid, gadoleic acid, erucic acid, linoleic acid, linolenic acid and ricinoleic acid.

Although these fatty acids can be added at the time of crushing or at the kneading step as described above, it is desirable to add them at the time of crushing in the sense that they are uniformly dispersed and adsorbed in the aluminum paste.

The total amount of fatty acids in the present invention is aluminum powder.
It is limited to the range of 7.0 parts by weight or less with respect to 100 parts by weight, and if it exceeds the upper limit, the coating film strength is rather impaired.

Further, the mixing ratio of saturated fatty acid and unsaturated fatty acid in the present invention is limited to the range of 9/1 to 1/9, but when the upper and lower limit values are exceeded, the influence of each fatty acid composition is emphasized. Therefore, good coating film adhesion could not be obtained.

The fatty acids of the present invention include one or more saturated fatty acids and
It is possible to add one or more unsaturated fatty acids, but it is optional to use a fatty acid having such a composition alone.

A typical commercially available product is (beef tallow fatty acid No. 1; NOF CORPORATION).

The aluminum paste composition of the present invention can include a myriad of combinations as described above, and examples and comparative examples will be shown below for several representative ones.

Example 1 Atomized aluminum (AC-1000 manufactured by Toyo Aluminum Co., Ltd.) 1.0 kg Mineral spirit 1.2 Oleic acid 50 g was put into a ball mill having a diameter of 50 cm and pulverized for 4 hours. After the completion of pulverization, the slurry was washed out with mineral spirit 20 containing 2 g / 100 ml of oleic acid and passed through a 250 mesh screen.

After that, solid-liquid separation was performed with a filter to obtain a filter cake composed of 80% by weight of aluminum. The filter cake contained about 1.0 part by weight of oleic acid per 100 parts by weight of aluminum. Using this filter cake, the effect of fatty acid composition on the coating film adhesion of the final aluminum paste composition was investigated. 1g, 2g, respectively
Add 5g, 10g, 20g, 40g, 60g, 90g of stearic acid to 1250g of each of the above filter cakes, adjust with mineral spirits so that the heating residue becomes 65%, and knead for 1 hour to obtain stearic acid / olein. The content ratio of acid is 1/10, 2/10, 5/10, 10/10, 20/1 by weight
An aluminum paste such as 0, 40/10, 60/10, 90/10 was obtained.

Comparative Example 1 In the same manner as in Example 1, the aluminum content was 78% by weight.
A filter cake consisting of The filter cake contained about 1.1 parts by weight of oleic acid per 100 parts by weight of aluminum. To this filter cake, 1.0 part by weight of oleic acid was added to 100 parts by weight of aluminum, and the mixture was adjusted with mineral spirits so that the heating residue was 65%, and the mixture was kneaded for 1 hour. I got a paste.

Comparative Example 2 A filter cake consisting of 76% by weight of aluminum was obtained in the same manner as in Example 1 except that stearic acid was used as the fatty acid contained in the lubricant and the slurry cleaning oil during grinding. The filter cake contained about 1.2 parts by weight of stearic acid per 100 parts by weight of aluminum. 1.0 parts per 100 parts by weight of aluminum in this filter cake
By weight, steariic acid was added, the heating residue was adjusted to 65% with mineral spirits, and the mixture was kneaded for 1 hour to obtain an aluminum paste containing fatty acid alone as stearic acid.

An adhesion test was conducted using the samples obtained in Example 1 and Comparative Examples 1 and 2.

The results are shown in Table 1. The adhesion test was performed using the following method.

Adhesion test A ship bottom paint was prepared with the following composition, and the coated plate spray-painted with the paint was immersed in an aqueous solution containing 3% of NaCl for 10 days at 40 ° C, and the adhesion before and after that was determined by a goggles adhesion test. Examined. As a method for testing the eye-to-eye contact, a cut is made with an NT cutter until the base is reached, a square is cut at 2 mm intervals, and a peel test is performed using a 24 mm wide cellophane tape manufactured by Nichiban Co., Ltd. Evaluated by number.

Adhesion × …… Inferior △ …… Available ○ …… Good ◎ …… Excellent Paint formulation 1. Ship bottom No. 1 paint composition Chlorinated rubber resin Supercron CR10 14g (Made by Sanyo Kokusaku Pulp Co., Ltd.) Kumaron resin V-120 7g (Made by Nippon Steel Chemicals) Ketone resin HK-111 3g (Made by Hitachi Chemical) Chlorinated paraffin A40S 3g Chlorinated paraffin A70 4g (manufactured by Toyo Soda Co., Ltd.) Rouge R-25 4g (manufactured by Nippon Bengal Industries Co., Ltd.) Talc SSS 11g (manufactured by Nippon Talc Co.) Barite 10g (manufactured by Nippon Kagaku Kogyo Co., Ltd.) Aluminum paste 16g (Example 1 and Comparative Example 1) , 2) Anti-sagging agent Desvalon 4110 0.5g (manufactured by Kusumoto Kasei Co.) Paint stabilizer Epicoat 828 0.5g (manufactured by Shell Yuka Epoxy Co., Ltd.) 3 Basic lead tribase 1g Xylol 26g Total 100g 2. Ship bottom No.2 antifouling paint composition Chlorinated rubber resin Supercron CR10 7.7g (manufactured by Sanyo Kokusaku Pulp Co., Ltd.) Tricresyl phosphate 3.7g Coumaron resin V-120 3.9g (manufactured by Nippon Steel Chemical Co., Ltd.) Hydrogenated Himai oil 0.5g Tributyltin fluoride 4.7g tributyltin oxide 0.6g cuprous oxide 26.1g lead suboxide 23.1g Solvesso 100 23.8 g mineral spirits 5.9g total 100 g painting underlying iron dull steel plate shop primer Ebabondo K (Chugoku Marine Paints, Ltd.) spraying dried at room temperature for 7 days Film thickness 13μ Ship bottom No. 1 paint Spray coating 3 times coating 1 time coating at room temperature 24 hours dry film thickness 40 μ x 3 times = 120μ Ship bottom No. 2 paint spray coating 2 coating room temperature 24 hours per coating film thickness 40 μ x 2 Times = 80μ As shown in Table 1, good coating film adhesion was obtained when the content ratio of stearic acid / oleic acid in the aluminum paste was in the range of 2/10 to 40/10. In the sample with a content ratio of stearic acid / oleic acid of 90/10, the content of fatty acid was too high at 10 parts by weight per 100 parts by weight of aluminum, rather the coating strength was impaired, and A cohesive failure phenomenon was observed.

Example 2 Grinding was carried out in the same manner as in Example 1 except that 25 g of stearic acid was used together with 25 g of oleic acid as a lubricant during grinding.

After the completion of the pulverization, the slurry was washed out with mineral spirits 20 and a filter cake consisting of 78% by weight of aluminum was obtained in the same manner as in Example 1 below. The filter cake contained about 0.1 part by weight of fatty acid per 100 parts by weight of aluminum.

To this filter cake, add the calculated amount of fatty acids mixed and adjusted so that the content ratio of stearic acid / oleic acid is 1/1, adjust with a mineral spirit so that the heating residue is 65%, and knead for 1 hour. As a result, the total amount of fatty acids contained was 0.1 and 0, respectively, per 100 parts by weight of aluminum.
An aluminum paste having 2, 0.5, 1.0, 2.0, 5.0, 7.0, 8.0 and 9.0 parts by weight was obtained.

Using the obtained aluminum paste, an adhesion test was conducted in the same manner as in Example 1.

The results are shown in Table 2.

When the total amount of fatty acids contained exceeds 7.0 parts by weight, the coating strength is rather deteriorated, and the phenomenon of cohesive failure within the coating film of ship bottom No. 1 was observed.

Example 3 3-1 A filter cake consisting of 80% by weight of aluminum was obtained in the same manner as in Example 1. The filter cake contained about 1.0 part by weight of oleic acid per 100 parts by weight of aluminum. Add lauric acid to this filter cake,
Palmitic acid and behenic acid were added in an amount of 1.0 part by weight per 100 parts by weight of aluminum, adjusted with a mineral spirit so that the heating residue was 65%, and kneaded for 1 hour to obtain an aluminum paste.

3-2 Furthermore, zomarinic acid, oleic acid, erucic acid and linoleic acid were added to the filter cake obtained in Comparative Example 2 in an amount of 1.0 part by weight per 100 parts by weight of aluminum, and the heating residue was 65% by mineral spirits. Thus, an aluminum paste was obtained by kneading for 1 hour.

An adhesion test was conducted using the samples obtained in Examples 3-1 and 3-2. The results are shown in Table 3.

Example 4 As a lubricant at the time of pulverization, the composition was 4% by weight of myristic acid, 30% by weight of palmitic acid, 20% by weight of stearic acid, 3% by weight of other saturated fatty acids, 35% by weight of oleic acid and 8% by weight of linoleic acid. It was pulverized in the same manner as in Example 1 except that 50 g of beef tallow fatty acid No. 1 (manufactured by NOF CORPORATION), which is such a commercially available fatty acid, was used. After crushing, the slurry was washed out with mineral spirit 20 containing 2 g / 100 ml of beef tallow fatty acid, and a filter cake consisting of 78% by weight of aluminum was obtained in the same manner as in Example 2.

This filter cake is approximately 100 parts by weight of aluminum.
It contained 1.0 part by weight of tallow fatty acid. To this filter cake, add 1.0 part by weight of beef tallow fatty acid per 100 parts by weight of aluminum, and heat with a mineral spirit to a residue of 65.
%, And the mixture was kneaded for 1 hour to obtain an aluminum paste.

Using the samples obtained in Example 4 and Comparative Examples 1 and 2, an adhesion test was conducted in the same manner as in Example 1. The results are shown in Table 4.

Claims (3)

[Claims] 1. An aluminum paste composition for ship bottom coatings containing a fatty acid and aluminum powder, wherein one or more fatty acids selected from straight chain saturated fatty acids having 12 to 22 carbon atoms are provided on the surface of each aluminum powder. An aluminum paste composition, wherein both one or more fatty acids selected from unsaturated fatty acids having 16 to 22 carbon atoms are adsorbed, and branched saturated fatty acids are not adsorbed. 2. A saturated fatty acid / unsaturated fatty acid content ratio of 9
The composition according to claim 1, wherein the composition is from 1/1 to 1/9. 3. A total amount based on 100 parts by weight of aluminum powder.
7. The composition according to claim 1, wherein the composition contains 7.0 parts by weight or less of a fatty acid.