JP3130225B2 - Method of forming silicone coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a silicone coating film having excellent adhesion between an intermediate coating film, an anticorrosion coating film, and a silicone rubber type top coating film, and having excellent durability and weather resistance.

[0002]

2. Description of the Related Art For the purpose of preventing soiling due to the adhesion of marine organisms to the surface of industrial water system equipment, water intake equipment such as nuclear power plants, marine structures, ships, etc., which are submerged in the sea, they are used as topcoat paints. Dirty paint is applied. Also ships,
2. Description of the Related Art For the purpose of preventing icing, outdoor communication equipment and the like are coated with an overcoat that forms an anti-icing coating film. Furthermore,
BACKGROUND ART For the purpose of preventing outdoor sticking, buildings such as telephone poles and telephone boxes are coated with a topcoat that forms a low-adhesive surface.

[0003] As a top coat paint which can be used as such an antifouling paint, anti-icing paint, paste preventing paint and the like,
In recent years, silicone rubber-based coatings containing various types of silicone oils called pollution-free types have begun to be used. Such a silicone rubber-based paint is generally used, for example, as an antifouling paint directly applied to a usual anti-corrosion coating or intermediate coating. However, when the coating film is formed in this way, the adhesion of the top coating film is poor,
There was a problem in durability in seawater and weather resistance at a submerged boundary portion washed with seawater.

In order to overcome these disadvantages, Japanese Patent Publication No.
Japanese Patent Application Laid-Open No. 9-48065 discloses a technique for forming a coating film by using an intermediate coating material for coating silicone rubber in which silicone rubber is mixed into a normal anticorrosive coating material. JP-A-3-258876 discloses a technique of forming a coating film by using a silicone-modified epoxy resin obtained by reacting dimethylpolysiloxane with an epoxy resin as an intermediate coating for coating silicone rubber. I have.

[0005]

However, in such a method, the adhesion between the obtained intermediate coating film and the silicone rubber-based coating film as the top coating film is insufficient, and furthermore,
When the silicone rubber-coated intermediate coating for silicone rubber is used, at the boundary between the coating of the intermediate coating and the anticorrosion coating on the inner side, blistering of the coating,
Peeling and the like occurred, which adversely affected the durability and weather resistance of the entire coating system.

In view of the above situation, the present invention provides a method of forming a silicone coating film having excellent adhesion between an intermediate coating film, an anticorrosion coating film, and a silicone rubber-based top coating film, and having excellent durability and weather resistance. The purpose is to provide.

[0007]

The gist of the present invention is to provide a method for forming a silicone coating film by forming a coating film having a softening point of 80% without forming an anticorrosion coating film or after forming the anticorrosion coating film.
A thermoplastic polyamide having an acid value of 10 or less and an amine value of 20 or less in an amount of 30 to 100% by weight of all resin components,
In addition, a room temperature drying type coating composition containing a hard resin in an amount of 0 to 70% by weight of the total resin component is applied, and then a silicone rubber-based top coating is applied. In the present specification, the “silicone coating film” means a coating film composed of the entire coating system using a silicone rubber-based overcoating film as the outermost layer. Hereinafter, the present invention will be described in detail.

In the present invention, when the object to be coated is a corrosive material such as a steel material, a known material such as a zinc-rich coating, a tar epoxy coating, an epoxy anticorrosion coating, or a urethane anticorrosion coating may be used, if necessary. After applying the anticorrosion paint and drying to form an anticorrosion coating, an intermediate coating is applied and dried, and then a top coating is applied to form a silicone coating. If the surface of the article to be coated is a concrete surface and the anticorrosion coating is not necessary, if necessary, a known undercoating treatment such as a permeation prevention treatment, an anti-floating treatment, and a putty pad for smoothing is applied. After performing, an intermediate coating can be applied and dried, and then a top coating can be applied to form a silicone coating.

In the present invention, a cold-drying coating composition containing a thermoplastic polyamide is used as the intermediate coating. The thermoplastic polyamide contained in the cold-drying coating composition is a condensate of a polycarboxylic acid and a polyamine, and has a softening point of 80 to 150 ° C and an acid value of 10.
Hereinafter, it is a resin which is solid at room temperature and has an amine value of 20 or less. The molecular weight of the thermoplastic polyamide is 4000 to 1
2000 is preferred.

The thermoplastic polyamide is not particularly limited. For example, Bar Salon 930 (Henkel Hakusui), Bar Salon 940 (Henkel Hakusui), Bar Salon 1117 (Henkel Hakusui), Bar Salon 112
9 (manufactured by Henkel Hakusui), Bar Salon 1128 (manufactured by Henkel Hakusui), Bar Salon 1128 (manufactured by Henkel Hakusui), DPXJ50 (manufactured by Henkel Hakusui), DPX80
2 (manufactured by Henkel Hakusui), DPX830 (manufactured by Henkel Hakusui), Sunmide 550-D (manufactured by Sanwa Kagaku), Sunmide 553 (manufactured by Sanwa Kagaku), Sunmide X-280
0 (manufactured by Sanwa Kagaku) and HT140E (manufactured by Sanwa Kagaku). These can be used alone or in combination of two or more.

The above-mentioned cold-drying coating composition used in the present invention may further contain a hard resin. The hard resin is not particularly limited as long as it has a softening point of about 100 ° C. and is solid at room temperature.
Examples include alkylphenol resins, coumarone indene resins, rosin esters, polymerized rosins, terpene resins, ester gums, phenolic resins, epoxy resins, and the like.Furthermore, epoxy-modified resins such as epoxy ester resins, epoxy acrylate resins, and epoxy polyol resins And the like. These can be used alone or in combination of two or more.

When the above-mentioned hard resin is blended,
The blending amount of the thermoplastic polyamide in the cold-drying coating composition used as the intermediate coating is 30% by weight or more of the resin component, and the blending amount of the hard resin is 70% by weight or less of the resin component. is there. If the thermoplastic polyamide is less than 30% by weight of the resin component and the hard resin is more than 70% by weight of the resin component, the flexibility of the dried coating film is lost and causes poor adhesion, so it is limited to the above range. Is done. Preferably, the thermoplastic polyamide is 50 to 95% by weight of the resin component, and the hard resin is 50 to 5% by weight of the resin component.

In the cold-drying coating composition used as an intermediate coating, the resin vehicle may be composed of only the thermoplastic polyamide, or may be composed of the thermoplastic polyamide mixed with the hard resin. In any case, the amount of the resin vehicle is preferably 3 to 80% by weight of the cold-drying coating composition. When the amount is less than 3% by weight, the coating film forming property is reduced, and when the amount is more than 80% by weight, the coating property and sagging property of the coating material are undesirably reduced. More preferably 10-5
0% by weight.

The above-mentioned cold-drying coating composition used in the present invention can contain a rust-preventive pigment for the purpose of imparting anticorrosive properties to itself. The rust preventive pigment is not particularly limited, for example, lead red, cyanamide lead, cyanamide zinc, zinc chromate, strontium chromate,
Metal compounds such as zinc phosphate, aluminum tripolyphosphate, tribasic lead sulfate, lead suboxide, zinc zinc cyanamide, aluminum molybdate, and basic lead chromate can be mentioned, and these can be arbitrarily selected. Can be blended.

When preparing the above-mentioned cold-drying coating composition used in the present invention, a solvent, a coloring pigment, an extender, a viscosity modifier and the like which are usually used in the coating composition can be blended. The preparation of the above-mentioned cold-drying coating composition used in the present invention can be performed by a method known in the art of paint production.

In the present invention, after applying the above-mentioned room temperature drying type coating composition as an intermediate coating, a silicone rubber type top coating is applied as a top coating. As the silicone rubber-based top coating, a silicone rubber-based coating composition containing a reaction-curable silicone rubber as a main resin and further blending various silicone oils as essential components is preferable. In the silicone rubber-based coating composition, the reaction-curable silicone rubber is a liquid containing a polyorganosiloxane having a crosslinkable reactive group, a silane compound as a crosslinking agent, a reaction catalyst and, if necessary, silica or the like. It exists as a mixture, and has a property of forming a coating film by a cross-linking reaction progressing when coated.

The silicone oil is a liquid silicone oil having a polyorganosiloxane as a main skeleton, and a silicone oil having only a methyl group as an organo group is referred to as dimethyl silicone oil. Various modified silicone oils substituted with a vinyl group, an alkyl group, an aralkyl group, an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a polyoxyalkylene group, and the like are also known. The silicone rubber-based coating composition may contain any of these silicone oils. In some cases, the silicone rubber-based coating composition may be a so-called two-pack type coating composition in which a reaction catalyst or a cross-linking catalyst is first separated and then mixed with a resin immediately before coating.

Examples of such a silicone rubber-based coating composition include a silicone rubber-silicone oil mixture obtained by curing an oligomeric silicone rubber having a hydroxyl end group at a low temperature in the presence of silicone oil; A composition in which a mixture with petrolatum or liquid paraffin and a silicone oil are mixed; a reaction-curable silicone resin and a silicone resin containing a polar group such as an amino group, a carboxyl group, an epoxy group, or a polyethylene glycol group. And the like.

In the present invention, the above-mentioned cold-drying coating composition and the above-mentioned silicone rubber-based top coating composition are applied by a known coating method such as airless coating, air spray coating, roller coating, brush coating, and the like. A film can be formed. The coating thickness of the above-mentioned cold-drying coating composition and the above-mentioned silicone rubber-based top coating composition can be set to a desired appropriate value depending on the application.

[0020]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Preparation of intermediate coating composition DPX-802 Varnish 45.0% by weight Titanium dioxide 10.0% by weight Talc 15.0% by weight Clay 15.0% by weight Xylol 10.0% by weight Isopropyl alcohol 5. 0% by weight The above components were converted into a coating using an SG dispersing machine to prepare an intermediate coating. In the above formulation, DPX-802 varnish is a 50% (xylol / isopropyl alcohol = 3/1) solution of a polyamide resin having an amine value of 10, an acid value of 3> and a softening point of 90 ° C, manufactured by Henkel Hakusui.

Production and Formulation of Silicone Rubber Antifouling Paint Silicone Rubber KE-45TS 60.0 wt% Silicone Oil KF-96 15.0 wt% Silicone Oil KF-53 15.0 wt% Xylol 10.0 wt% The components were mixed with a homomixer to prepare a silicone rubber antifouling paint for testing. In the above compounding, silicone rubber KE-45TS is a room temperature reaction-curable deoxime-type silicone rubber varnish manufactured by Shin-Etsu Chemical Co., Ltd. (volatile content: 50%).
It is. Silicone oil KF-96 represents polydimethylsiloxane oil manufactured by Shin-Etsu Chemical Co., Ltd., and silicone oil KF-53 represents polymethylphenylsiloxane oil manufactured by Shin-Etsu Chemical Co., Ltd., respectively.

The obtained intermediate coating is applied to a 15 cm × 10 c
A test steel plate of mx 1.6 mm was coated with an airless coater so as to have a dry film thickness of about 40 µm, and was air-dried for 3 days. In addition, the test steel sheet was prepared by using a tar epoxy anticorrosion paint (Epotal BO,
Nippon Paint Co., Ltd., one type of JIS K5664) was applied and air-dried for 3 days. On a test steel sheet coated with an intermediate coating and dried, further, as an overcoat, the obtained silicone rubber antifouling coating for test was applied with an airless coating machine so as to have a dry film thickness of about 100 μm. The test steel sheet was air-dried for 3 days and subjected to antifouling coating.

Performance test An X-shaped cut was made on the prepared anti-fouling test steel sheet with a cutter blade so as to reach the tar epoxy anti-corrosion coating film, and then submerged with an underwater raft off Tamano City, Okayama Prefecture. About 5
It was immersed at a depth of 0 cm, and the adhesion of the intermediate coating film to the tar epoxy anticorrosion coating film and the top coating silicone rubber antifouling coating film, and the durability of the entire coating film were evaluated. Table 1 shows the results
It was shown to. The evaluation criteria were as follows. ：: No peeling or swelling near the cut area △: Peeling or swelling near the cut area ×: Peeling or swelling other than the cut area

Example 2 A test steel sheet having an antifouling coating was prepared, tested, and evaluated in the same manner as in Example 1 except that an intermediate coating was produced using the following components. The results are shown in Table 1. Formulation DPX-802 varnish 30.0% by weight Hitanol 1002 varnish 15.0% by weight Titanium dioxide 10.0% by weight Talc 15.0% by weight Clay 15.0% by weight Xylol 10.0% by weight Isopropyl alcohol 5.0% by weight In the above formulation, Hitachil 1002 Varnish is a 50% (xylol / isopropyl alcohol = 3/1) solution of an alkylphenol resin manufactured by Hitachi Chemical Co., Ltd.

Example 3 A test steel sheet subjected to antifouling coating was prepared, tested and evaluated in the same manner as in Example 1 except that an intermediate coating was produced using the following components. The results are shown in Table 1. Formulation DPX-802 Varnish 14.0% by weight Hitanol 1002 Varnish 31.0% by weight Titanium dioxide 10.0% by weight Talc 15.0% by weight Clay 15.0% by weight Xylol 10.0% by weight Isopropyl alcohol 5.0% by weight

Example 4 A test steel sheet subjected to antifouling coating was prepared, tested and evaluated in the same manner as in Example 1, except that an intermediate coating was produced using the following components. The results are shown in Table 1. Formulation DPX-802 varnish 22.5% by weight Hitanol 1002 varnish 22.5% by weight Titanium dioxide 10.0% by weight Talc 15.0% by weight Clay 15.0% by weight Xylol 10.0% by weight Isopropyl alcohol 5.0% by weight

Example 5 A test steel sheet subjected to antifouling coating was prepared, tested and evaluated in the same manner as in Example 1 except that an intermediate coating was produced using the following components. The results are shown in Table 1. Formulation DPX-802 varnish 42.0% by weight Hitachil 1002 varnish 3.0% by weight Titanium dioxide 10.0% by weight Talc 15.0% by weight Clay 15.0% by weight Xylol 10.0% by weight Isopropyl alcohol 5.0% by weight

Comparative Example 1 The same procedure as in Example 1 was carried out except that the following compound (A) and compound (B) were charged in a container at a weight ratio of 80:20, and sufficiently stirred and mixed with a mixer to produce an intermediate coating. In the same manner, a test steel sheet subjected to antifouling coating was prepared, tested, and evaluated. The results are shown in Table 1. Formulation (A) ES-1002T 40.0% by weight Titanium dioxide 15.0% by weight Precipitable barium sulfate 15.0% by weight Graphite 10.0% by weight Talc 10.0% by weight Bentonite 1.0% by weight Xylol 7.0 % By weight Cellosolve acetate 2.0% by weight Formulation (B) Sunmide X-2800 50.0% by weight Toluol 30.0% by weight n-butanol 10.0% by weight Methyl isobutyl ketone 10.0% by weight In the above formula, ES- 1002T is a silicone-modified epoxy resin varnish manufactured by Shin-Etsu Chemical Co., Ltd.
% Of dimethylpolysiloxane and about 30% of dimethylpolysiloxane, and has a solid content of 60%. Sunmide X-28
00 is a polyamide resin varnish manufactured by Sanwa Chemical Industry Co., Ltd., having a solid content of 70%, a polyamide adduct type, and an active hydrogen equivalent of about 150.

[0030]

[Table 1]

According to the examples, silicone having excellent adhesion of the intermediate coating film, no swelling or peeling at the interface between the anticorrosion coating film and the silicone rubber top coating film, and having excellent durability and weather resistance. It was found that a rubber-based antifouling coating film could be formed.

[0032]

According to the present invention, an intermediate coating film and an anticorrosion coating film,
It is possible to provide a method for forming a silicone coating film having excellent adhesion to a silicone rubber-based overcoating film, and having excellent durability and weather resistance.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-137231 (JP, A) JP-A-51-96830 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05D 1/00-7/26 C09D 177/06 C09D 183/04

Claims (2)

(57) [Claims] 1. A coating material having a softening point of 80 to 150 ° C. without forming an anticorrosion coating film or after forming an anticorrosion coating film.
A cold-drying coating composition containing 30 to 100% by weight of a total resin component of a thermoplastic polyamide having an acid value of 10 or less and an amine value of 20 or less and 0 to 70% by weight of a total resin component. A method for forming a silicone coating film, which comprises applying a silicone rubber-based overcoating material after coating. 2. The method for forming a silicone coating film according to claim 1, wherein the silicone rubber-based topcoat is a silicone rubber-based topcoat containing a reaction-curable silicone rubber composition and a silicone oil.