JPH0493372A - Primer composition for plastic flame spray coating film - Google Patents

Abstract

PURPOSE:To obtain a primer compsn. for plastic flame spray coating film excellent in adhesion to the plastic flame spray coating film and, when applied to marine structures, capable of greatly improving the corrosion resistance of the flame spray coating film even in the injured parts by compounding a specified acrylonitrile-butadiene resin with a specified cement of sulfur or sulfur compd. CONSTITUTION:A primer compsn. is produced by compounding an acrylonitrile- butadiene resin having a mol.wt. of 200,000-800,000 and represented by the formula (wherein n and m are each an integer representing the no. of recurring units and n:m is 1:1 to 1:9) as a main ingredient with sulfur or a sulfur compd. (e.g. thiuram sulfide, thiazole compd., dithiocarbamate, sulfur chloride or the like) at a ratio of 100:0.2 to 100:10 by wt. The compsn. thus obtd. is excellent in adhesion to a plastic flame spray coating film. When applied to marine structures, it can greatly improve the corrosion resistance of the flame spray coating film even in injured parts.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a primer composition for thermal sprayed coatings on plastics, and more specifically, it has excellent adhesion to thermally sprayed coatings on plastics, and particularly when applied to marine structures, etc. , relates to a brimer composition that can greatly improve the corrosion resistance of damaged areas of thermal spray coatings.

Conventional technology The so-called plastic thermal spraying technology, in which metal substrates are thermally sprayed with powder of polymer compounds such as polyethylene powder or nylon powder, has been attracting attention for a long time. Progress has been made to improve thermal spraying technology and to make it possible to apply plastic powder to large substrates without preheating the metal substrate. As a result, today polyethylene, EVA, epoxy, polybutene,
A technique (for example, JP-A No. 60, No. 2002) in which a thermal spray paint made of powdered resin such as fluororesin, or a room-temperature liquid adhesive brimer made of polychloroprene, urethane resin, or epoxy resin is applied to the base material, and then a thermal spray paint is applied to the base material (for example, -153968
, No. 60-153969) has been established and is attracting attention in various painting fields. This is because, unlike ordinary paints, plastic thermal spraying allows the use of higher molecular weight synthetic resins, which are then heated and thermally sprayed to form a film, resulting in improved physical properties such as mechanical strength, water resistance, and impact resistance. Improvements in thermal spraying machines have led to the emergence of more efficient coating methods, which have made film formation easier, and the disadvantages of relatively poor adhesion to metal substrates.
This is because the problems overcome by the development of adhesive brimers have greatly contributed to the development of plastic-nuc thermal spraying technology.

However, when completely covered with a plastic film, it has excellent water resistance, weather resistance, and ability to block corrosive substances, and corrosion resistance can be expected, but the film is easily damaged by mechanical and physical impacts such as those of marine structures. In the case of painted objects, corrosion from damaged areas and peeling of the paint film easily occur, and problems of both corrosion resistance and adhesion cannot be resolved.
The current situation is that plastic spraying on so-called offshore structures such as oil and gas drilling platforms, rigs, offshore facilities, plants, aquapolis, submarine vibrators, floating breakwaters, and ships has not been seen again.

In addition, conventional brimers, which were developed to improve the adhesion of thermal sprayed plastic coatings to steel surfaces, were developed with the sole aim of ensuring the adhesion of thermal sprayed coatings without preheating the base material. Because it was
Corrosion of damaged parts of thermal sprayed coatings and water resistance have not been resolved, and chlorine-based resins such as polychloroprene-based brushers decompose due to the heat during thermal spraying and easily produce dehydrochloric acid, which affects the corrosion resistance of steel materials. 6 Problems to be Solved by the Invention Therefore, a brimer composition for plastic thermal spraying WI, which has excellent adhesion to thermal spray coatings and substrates, and which is suitable for marine structures. A primer that does not cause deterioration in corrosion resistance or water resistance due to paint peeling even when applied to substrates that are easily damaged by thermal spray coatings such as chlorine-based resins, and there is no problem of corrosion resistance deterioration during thermal spraying. It is one of the main objects of the present invention to provide a composition. Another object of the invention is to provide a 7-limer composition for plastic thermal spray coatings that enables plastic thermal spraying, particularly for marine structures, and has excellent impact resistance. Furthermore, marine structures typically require coatings that are durable for a long period of 10 to 15 years. Another object of the invention is to provide a primer composition that can sufficiently exhibit impact resistance and corrosive substance barrier properties.

Means for Solving the Problems According to the present invention, the above-mentioned object of the invention is achieved by using the formula % as a main component, where n and m are integers representing the number of repeating units,
Molecular weight expressed as n:m=1:1 to 1:9) 200.0
01) to 800,000 acrylonitrile butadiene resin and sulfur or sulfur compound in a weight ratio of 100:
This can be achieved by a primer composition for plastic thermal spray coatings containing the primer composition in a ratio of 0.2 to 100:10.

In addition, the term "for plastic thermal spray coatings" used in the present invention refers to ethylene vinyl acetate copolymer (EVA)
, polyethylene, polyamide, ethylene methacrylic acid copolymer, nylon, polybutene, epoxy resin, fluororesin, etc. are thermally sprayed using a flame of propane/air, acetylene/oxygen, etc. It is intended to be used as a preliminary treatment for the purpose of forming a plastic coating film.

The primer composition according to the present invention has the formula CN ■ →CH2-C11h=-→C1-12-CH=C)(-
Molecular weight 200,000 ~ soo, ooo acrylonitrile butadiene expressed by CI (biaxial - (in the formula, n and m are integers representing the number of respective repeating units, n:m = 1:1 ~ 1:9) A copolymer resin and sulfur or a sulfur compound known as a vulcanizing agent for the resin are mixed at 10[)+0
．． The content is in a weight ratio of 2 to 100:10.

The above acrylonitrile-butadiene copolymer resin is a copolymer of butadiene and 10 to 50% acrylonitrile, and is a type of synthetic rubber known as butadiene-acrylonitrile rubber, but it is soluble in solvents and has a relatively low molecular weight. Since copolymers have low adhesive strength, they have been put to practical use in the fields of adhesives, cement, etc. by adding a vulcanizing agent such as sulfur or a sulfur compound and vulcanizing them by heating.

However, in the paint field, no attempt has been made to utilize such synthetic rubbers as undercoats, intermediate coats, etc. from the viewpoint of coating film appearance, coating performance, etc.

The present inventors discovered that a liquid composition of acrylonitrile butadiene copolymer with a relatively low molecular weight has excellent thermal stability.
Good adhesion to steel surfaces and zinc-rich paint; When combined with a vulcanizing agent, it is vulcanized by high-temperature heating during plastic thermal spraying, greatly increasing the adhesion strength. Plastic thermal spraying such as EVA and polyethylene. It has extremely good adhesion to the coating film, and does not cause thermal decomposition even at high temperature heating during thermal spraying, for example, 80 to 200°C.
I learned that vulcanized rubber itself has excellent impact resistance and adhesion, and therefore is ideal as a primer for plastic thermal spray coatings, especially for plastic thermal spray coatings on marine debris, so I decided to book this book. Completed the invention.

Acrylonitrile butadiene resins having a molecular weight of about 200,000 to 800,000 are conveniently used, and for example, commercially available products such as JSRN250S (Japan Synthetic Rubber Co., Ltd., Nitrile Rubber, Buner N, etc.) are used. It should be noted that a primer obtained by copolymerizing an acrylonitrile butadiene copolymer with a very small amount of a third monomer may also be used as long as the properties of the acrylonitrile butadiene copolymer are not drastically changed. The vulcanizing agent used in the composition is usually sulfur or sulfur compounds used for the purpose of vulcanizing acrylonitrile butadiene resins, such as sulfur; thiurams such as tetramethyl 10ram sulfide and tetrabutylthiuram disulfide; Thiazole compounds such as 2-methylcaptobenzothiazole and dibenzothiazole disulfide; dithiocarbamates such as zinc diethyldithiocarbamate; sulfur chloride, sulfur dioxide; disulfides such as molar disulfide and alkylphenol disulfide, etc. are preferably used. It will be done.

As already mentioned, the strength of the primer is low when using acrylonitrile butadiene resin alone, and when exposed to external forces such as impact, the adhesion of the thermally sprayed coating is poor and peeling occurs. When a vulcanizing agent made of sulfur or a sulfur compound is used in combination, the acrylonitrile butadiene resin is vulcanized by the heat during thermal spraying, and its adhesion to the plastic thermally sprayed coating is greatly improved. In this case, if the amount of the vulcanizing agent is small, for example, less than 0.2 parts per 100 parts of the resin, the purpose of vulcanization and the effect of increasing adhesive strength cannot be expected, and the mechanical strength will also be insufficient.
When it exceeds 0 parts, vulcanization progresses too much, and impact resistance deteriorates on the contrary. Therefore, the amount of vulcanizing agent should be in the range of 0.2 to 10 parts by weight, preferably 1 to 7 parts by weight, based on 100 parts by weight of acrylonitrile butadiene resin.

As described above, the primer composition according to the present invention contains acrylonitrile butadiene resin and sulfur or a sulfur compound as essential components in the above proportions, and is applied to steel materials or zinc-rich paint-coated steel materials by conventional brush printing, roller painting, The acrylonitrile butadiene resin is vulcanized when applied by air spraying or airless spraying, and the adhesion and adhesion strength with the plastic sprayed coating are greatly increased. Under submerged conditions, it is possible to obtain stable corrosion resistance over a long period of time due to extremely excellent coating adhesion and water resistance on healthy and damaged areas of the coating.

In addition to the above-mentioned essential components, the brimer composition of the present invention may optionally contain various brimer paint additives, such as tackifiers for resins that soften at around 100°C, e.g. Rosin, ester gum, polyterpene resin, C2 petroleum resin, C9 petroleum resin, terpene phenol resin, etc.; Rust preventive pigments, such as zinc phosphate, lead cyanamide, strontium chromate, zinc chromate, etc.; Coloring pigments, such as titanium oxide, carbon, iron oxide,
Phthalocyanine blue, etc.; extender pigments, such as precipitated barium sulfate, clay, talc, calcium carbonate, etc.; solvents (
Solvent for dissolving acrylonitrile butadiene and making it into a paint form) For example, methyl ethyl ketone, tetrahydrofuran, ethylene dichloride, methyl glycol acetate, etc. 1 Dispersant, surface preparation agent, thickener, anti-settling agent, and other paint additives It's something known as a drug.

The brimer composition according to the present invention is adjusted to an appropriate viscosity with a solvent, etc., and then applied directly to the steel material or to the steel material after being coated with zinc-rich paint by a conventional method such as roller, brush coating, air spray, or airless soufflé. After drying at room temperature, it is subjected to plastic spray painting.

The heat during plastic spraying causes the brimer composition to vulcanize the acrylonitrile butadiene resin, greatly increasing the adhesion of the resin and firmly bonding the plastic coating, thereby preventing the submersion of marine elliptical relics. Also, it prevents the paint film from peeling off on areas damaged by collisions with driftwood, ships, etc., provides highly reliable corrosion resistance, water resistance, etc., and maintains the excellent properties of plastic paint films for a long time. It is possible to force it.

The present invention will be explained below with reference to Examples.

In addition, in the examples and comparative examples below, unless otherwise specified, parts represent parts by weight.

Example 1 Acrylonitrile butadiene resin (JSRN250S,
Manufactured by Nippon Synthetic Rubber ■, the above formula: n:m=1:4, molecular weight: 500,000 0.4 part of thiuram sulfide and 0.5 part of zinc chrome ZTO (manufactured by Kikuchi Shikoku Kogyo ■) were added, and the mixture was stirred and mixed uniformly with a disper to obtain a brimer composition (1).

Comparison 11MI acrylonitrile butadiene resin (JSRN25O3)
A comparative brimer composition (2) was obtained according to the method of Example 1 using 15 parts of zinc chromate ZTO, 0.5 parts of zinc chromate ZTO, and 84.5 parts of methyl ethyl ketone.

Comparative Example 2 Acrylonitrile butadiene resin (JSRN25 OS
> 15.0 parts, 1.6 parts of tetramethylthiuram sulfide, 5 parts of zinc chromate ZTO1], 4.9 parts of toluene and 78.0 parts of methyl ethyl ketone,
A comparative brimer composition (3) containing an excessive amount of vulcanizing agent was obtained using the same method as in Example 1.

Example 2 Acrylonitrile butadiene resin (JSRN25OS>
15.0 parts, tetramethylthiuram sulfide C1,
4 parts, rosin ester (manufactured by Arayo Kagaku Kogyo ■) 6.5 parts,
A brimer composition (4) was obtained according to the method of Example 1 using 0.5 parts of zinc chromate ZTO, 7.6 parts of toluene and 70.0 parts of methyl ethyl ketone.

Comparative Example 3 Using chlorobrene (neoprene WHV, manufactured by Showa Denko DuPont Co., Ltd. > 15.0 parts, 6.5 parts of rosin ester, 5 parts of zinc chromate ZTOO, 8.() parts of toluene, 70.0 parts of methyl ethyl ketone), Example According to method 1,
A comparative primer composition 5) outside the invention was obtained.

Using the 7 limer compositions of the above Examples and Comparative Examples, painting and plastic spraying were carried out as described below, and each of the primers was evaluated.

Sandblasted steel plate (Swedish standard Sa 3.
0) was coated with Nippesinki-8000 (organic zinc rich paint, manufactured by Nippon Paint Co., Ltd.) using an airless spray method to a dry film thickness of 10 to 15μ, and dried at room temperature at 20°C (116°C).
A sample board was made by leaving it for some time.

Next, the primer compositions obtained in each of the Examples and Comparative Examples were applied to a dry film thickness of 30 to 50 μm using an air spray method, and dried at 20° C. for 16 hours.

After that, (A) Dumilan C-157 was used as a thermal spray paint.
Either 0' (modified ethylene vinyl acetate powder, manufactured by Ota Pharmaceutical ■) or (B) Himilan 1702 (ethylene methacrylic acid ionomer powder, manufactured by DuPont Mitsui ■) was sprayed using a plastic thermal spraying machine (CT-300, Nippon Kochitsuk Co., Ltd.). Co., Ltd.) using a flame with a propane/'air mixture ratio of -1y' 18 to produce a thermal sprayed coating film of 1501:] to 200 μm.

For comparison purposes, in Comparative Example 4, a thermal spray paint was applied directly to the zinc-rich paint film without applying a brimer.

The above coated plates were tested for corrosion resistance, impact resistance, and adhesion using the following methods, and the results are shown in Table 1.

Test method and evaluation criteria Corrosion resistance: (A) Chloride spray test - Make a cut with a length of 50°C in the center of a 7X15C11 test plate with a knife cutter until it reaches the substrate, and heat it at 20°C for 30 minutes.
% saline solution was sprayed for 1000 hours, and the peeling process (strength) on one side of the cut portion was measured. In the table, if it says peeling or 20 or more,
Refers to complete peeling of the paint film.

(B) Salt water immersion test As in (A), a test plate cut with a knife cutter was immersed in 40°C 13% saline solution for 3 months, and the peeling period (am) on one side of the cut portion was measured.

(C) Electrostatic protection test (cathode peeling test) (Similar to A>, using a test plate cut with a knife cutter, 20℃,
The test plate was connected with zinc wire in 3% saline solution, and after being immersed and held for 3 months, the degree of peeling on one side of the cut portion (<am) was measured.

Impact resistance: CD) Impact resistance test: Using a Cardner impact tester, a 1 kg impact center was dropped from a height of 1 m, and if peeling under the paint film occurred, it was evaluated as ×, and if no peeling occurred, it was evaluated as ○. .

Adhesion: (E) Without cutting the test coated plate, the adhesion tester was used to measure the adhesion of the paint film on the healthy area before and after conducting the salt water immersion test under the same conditions as in (B). (manufactured by Elcometer). An adhesion force of 20 kg/- or more was evaluated as a pass (○), and an adhesion force of 20 kg/- or more was evaluated as a failure (×).

Claims (2)

[Claims] (1) The main components include formulas, mathematical formulas, chemical formulas, tables, etc. (In the formula, n and m are integers representing the number of repeating units,
Molecular weight expressed as n:m=1:1 to 1:9) 200.0
00-800,000 Acrylonitrile butadiene resin and sulfur or sulfur compound in a weight ratio of 100:0
．． Primer composition for plastic thermal spray coating film containing in a ratio of 2 to 100:10 (2) The composition according to claim 1, wherein the sulfur compound is at least one selected from the group consisting of thiuram sulfide, thiazole compounds, dithiocarbamates, sulfur chloride, and disulfide compounds.