JPH0621268B2 - Coating agent - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coating agent, and more particularly to a coating agent containing water and capable of evaporating water in a short time after coating.

[Prior Art] As a coating agent to be applied to various materials such as metal and wood for the purpose of rusting, waterproofing, etc., conventionally, a coating agent comprising a salt of an isobutylene-maleic anhydride copolymer and water is known. In general, such a coating agent is applied to the surface to be coated, water is evaporated, and then curing is performed under predetermined conditions.

[Problems to be Solved by the Invention] Although such a conventional coating agent has a relatively excellent function in terms of rust prevention or waterproofing, it takes a long time to evaporate the water content after application, so There is a problem that coating, that is, the thickness of the coating layer cannot be increased, and that it takes a long time for the overall curing including the evaporation of water.

An object of the present invention is to provide a coating agent which solves the conventional problems described above, allows the contained water to evaporate in a short time after coating, enables thick coating, and shortens the overall curing time.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the inventors of the present invention have conducted intensive studies focusing on the copolymerization component of the copolymer, and as a result, have studied the conventional secondary system described above. The present inventors have completed the present invention by finding that an excellent effect can be obtained when a specific three-dimensional copolymer is used as a coating agent component instead of the polymer.

That is, the coating agent of the present invention comprises (A) 1 part of isobutylene and 0.5 to 10 mol of maleic acid or its anhydride and 0.01 to 1.5 mol of styrene or an acrylic acid compound as a structural unit. 100 parts by weight of a salt of the copolymer or a mixture of salts of these copolymers, and (B) water in an amount of 100 to 2,000 parts by weight.

[Detailed Description] As described above, the coating agent of the present invention comprises an isobutylene-maleic acid or its anhydride-styrene copolymer salt, an isobutylene-maleic acid or its anhydride-acrylic acid compound copolymer. It is characterized by containing a salt or a mixture of salts of these two ternary copolymers. The acrylic acid-based compound is not particularly limited, for example, methyl acrylate,
Ethyl acrylate, propyl acrylate, butyl acrylate, actyl acrylate and the like are preferable. The coating agent of the present invention contains a salt of such a terpolymer as a constituent component, and as such a salt, for example, sodium salt, potassium salt or ammonium salt is preferable.

The salt of the ternary copolymer is produced, for example, as follows. That is, first, a predetermined amount of each copolymerization component except isobutylene is charged into a reaction vessel, cooled and sufficiently deaerated. Then, a predetermined amount of isobutylene is added and the copolymerization reaction is carried out while stirring. At this time, the reaction temperature is set to 30 to 200 ° C., preferably 45 to 150 ° C., and the reaction time is set to 0.5 to 20 hours, preferably 1 to 10 hours.
In this copolymer reaction, if necessary, a solvent such as acetonitrile, nitromethane, nitroethane, methyl ethyl ketone, acetone, N, N-dimethylformamide, dimethyl sulfoxide, benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, A catalyst such as tertiary butyl hydroperoxide, dicumyl peroxide and azobisisobutyronitrile can be used.

Then, the copolymer thus obtained is neutralized with an alkali to form a salt of the copolymer. At this time, as the alkali used, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate,
Ammonia, sodium acetate, urea, thiourea, organic amines and the like are preferable. The reaction temperature of this neutralization reaction is 20-
It is preferable to set the reaction temperature to 150 ° C. and the reaction time to 0.5 to 10 hours.

The coating agent of the present invention contains the salt of the ternary copolymer and water as essential components, and the compounding amount of both is 3%.
100 to 2000 parts by weight of water based on 100 parts by weight of the original copolymer,
Furthermore, it is preferable to set it to 200 to 1000 parts by weight.

Furthermore, the coating agent of the present invention, in addition to the above essential components, if necessary, titanium oxide, calcium carbonate,
Inorganic fillers such as barium sulfate, zinc oxide, aluminum oxide, magnesium oxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, talc and clay;
Polyvinyl alcohol, carboxymethyl cellulose,
A water-soluble resin such as hydroxymethyl cellulose, hydroxyethyl cellulose, starch, glue, sodium polyacrylate, etc .; a plasticizer such as dioctyl phthalate, dibutyl phthalate, di (2-ethylhexyl) adipate, or tricresyl phosphate may be contained.

The coating agent of the present invention obtained as described above,
As a coating agent for surface protection such as rust prevention, waterproofing, adhesive base or scratch prevention, metal, wood, glass,
It can be applied to various materials such as paper, plastics, asbestos and concrete.

[Examples] Examples 1 to 4 An autoclave having an internal volume of 1 was charged with the indicated components excluding isobutylene in the indicated amounts and cooled to -10 ° C.
The inside of the container was thoroughly degassed. Then, the indicated amount of isobutylene, 460 cc of acetonitrile as a solvent, and 0.6 g of benzoyl peroxide as a catalyst were added, and a copolymerization reaction was carried out at 110 ° C. for 2 hours. Then, the product was put into water to obtain a copolymer. . The number average molecular weight, acid value (mgKOH / g), amount of styrene (% by weight) and amount of methyl acrylate (% by weight) of the obtained copolymer are shown in the table.

Then, an aqueous solution of sodium hydroxide having a neutralization degree of 1 was added to this copolymer to make its concentration 20% by weight, and a neutralization reaction was carried out at 90 ° C. for 6 hours to form a salt of the copolymer. A coating agent of the present invention was obtained.

The coating agent thus obtained was spread on a petri dish having an inner diameter of 90 mm to a thickness of 1 mm to form a coating film, and the coating film was left standing in the air to measure the weight loss rate every hour. The touch-drying time of this coating film was measured according to JIS K 5400, and the above results are shown in the table.

Example 5 A coating agent was prepared in the same manner as in Examples 1 to 4 except that the copolymers obtained in Examples 2 and 4 were mixed in a weight ratio of 1: 1. After manufacturing, the same evaluation test was performed and the results are shown in the table.

Comparative Example 1 A copolymer and a coating agent were prepared in the same manner as in Examples 1 to 4 except that only the two components shown were used as copolymerization components. It was shown to.

Comparative Example 2 In the copolymerization reaction, the above-mentioned comparison was conducted except that n-butyl acetate was used as a solvent and azobisisobutyronitrile was used as a catalyst, the reaction temperature was 55 ° C., and the reaction time was 6 hours. After the copolymer and the coating agent were produced in the same manner as in Example 1, the same evaluation test was conducted and the results are shown in the table.

[Effects of the Invention] As is clear from the above description, since the coating agent of the present invention quickly evaporates water after application, the curing time including the water evaporation step can be significantly shortened as compared with the conventional coating agent. Therefore, it is extremely useful as a coating agent for various materials such as metal, wood, glass, etc. for rust prevention, waterproofing, adhesive base or surface protection, and its industrial value is great.

Claims (1)

[Claims] 1. A copolymer comprising 0.5 to 10 mol of maleic acid or its anhydride and 0.01 to 1.5 mol of a styrene or acrylic acid compound per 1 mol of (A) isobutylene. A coating agent containing 100 parts by weight of the above salt or a mixture of salts of these copolymers, and (B) 100 to 2,000 parts by weight of water.