JPH06172701A - Coating composition preventive of damage by adherent marine organism - Google Patents

Abstract

PURPOSE:To obtain a coating compsn. capable of forming a thick coating film long in corrosion-proofing life span, hardly causing deep-rootedness of adherent marine organisms and mechanical damage during removal therefrom of such organisms, and hence free from the necessity for repair, by using a liq. urethane resin as the main component. CONSTITUTION:A diisocyanate is blended with a polyol and a chain extender to obtain a liq. urethane resin. An elastic polyurethane coating material is used as the liq. urethane resin. The surface of an object is cleaned by sandlasting a treatment with a disc-sander, or the like, then coated with a primer suitable for the elastic polyurethane coating material, then dried, and spray-coated with the elastic polyurethane coating material. The elastic polyurethane coating material is generally of a two-pack type. Accordingly, the two ingredients of the elastic polyurethane coating material are mixed together before application thereof in the case of a long pot life, while the two ingredients are sprayed for coating therewith while being mixed together in the case of a short pot life.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition capable of forming a coating film which is not damaged by marine attached organisms. The coating composition according to the present invention includes, for example, seawater circulating water pipes, seawater intake facilities (sluice gates, screens, etc.), floating piers, buoy buoys, floating breakwaters, marine redelow facilities (underwater observation towers, sea fishing piers, etc.), marine It can be applied to energy-related equipment (wave power generation equipment, offshore oilfield drilling equipment, etc.) and large offshore floating structures (sea port calls, maritime cities, etc.). Since marine organisms adhere to the above-mentioned underwater structures, which causes obstacles such as weight increase and blockage, it is necessary to periodically remove marine organisms.

[0002]

2. Description of the Related Art Conventionally, structures in contact with seawater are generally made of concrete or steel materials, and in particular, steel structures are coated with various paints to prevent corrosion.
However, since the adhesion of marine life is inevitable,
They must be removed before marine organisms cause attachment damage. However, conventional anticorrosion coatings (for example, oily, vinyl resin, chlorinated rubber, tar epoxy resin, epoxy resin, asphalt enamel, coal tar, enamel, etc.) are thin films and have a short anticorrosion life, which prevents the intrusion of adherent organisms. Mechanical damage during removal of living organisms is liable to be repaired, which requires a great deal of expense and time. On the other hand, there are thick film epoxy and urethane paints that do not damage organisms, but it is often difficult to remove organisms with these paints.

In view of the above points, an object of the present invention is to provide a thick coating film which has a long anticorrosive life, is unlikely to be ingested by adhered organisms and is not easily mechanically damaged when removing organisms, and does not require repair. It is to provide a coating composition that can be formed.

[0004]

The coating composition according to the present invention has been devised to achieve the above object and is characterized by comprising a liquid urethane resin.

As the liquid urethane resin, for example,
An ultra-thick film type elastic polyurethane paint such as "Ureol RIM (PD-190)" (manufactured by Kawakami Paint Co., Ltd.) or "Techtan 98SS" (manufactured by American Technical Urethane Co.) is used.

Liquid urethane resins are listed, for example, in Table 1 below.
It is a mixture of the diisocyanate, the polyol, and the chain extender (crosslinking agent) shown in.

[0007]

[Table 1] Diisocyanate MDI = 4,4′-diphenylmethane diisocyanate TDI = Tolylene diisocyanate NDI = Naphthylene diisocyanate TODI = Tolidine diisocyanate polyol P-CL = Polycaprolactone PTMG = Polyoxytetramethylene glycol PPG = Polypropylene glycol Chain extender (crosslinking agent) EG = Ethylene glycol 1,4-BG = 1,4-butylene glycol BHEB = bis (β-hydroxyethyl) benzene TMP = trimethylolpropane

[0008]

EXAMPLES Next, in order to specifically explain the present invention, some examples of the present invention and comparative examples for showing comparison with the examples will be given, and the performance test results of the obtained coating films will be shown. Show.

Examples 1 to 2 a) Coating example of elastic polyurethane paint The surface of the coated surface is sandblasted (grade: SI
S Sa2.5) and dissender processing (grade:
After cleaning with steel material surface treatment standard spss Pt3) before coating, etc., a primer (preferably a dedicated primer) suitable for elastic polyurethane coating is thinly applied (film thickness 10 to 30 μm) by spraying or brushing. Then 2
After drying for 0 minutes to 3 hours, an elastic polyurethane paint is applied by spraying to a thickness of 2000 to 3000 μm. The elastic polyurethane paint is generally a two-part type, and when the pot life after mixing is long, the two parts are mixed in advance before coating and the mixed liquid is applied by a general spray coating machine.
However, in the case of an elastic polyurethane paint with a short pot life, it is possible to spray paint while mixing two liquids.
Use a head gun type painting machine.

B) Coating example of ultra-thick elastic polyurethane coating 1. In the case of "Ureol RIM (PD-190)" (manufactured by Kawakami Paint Co., Ltd.) (1) Preparation of test plate base material: blast treatment (Sa2.5) (2) Primer coating: UP primer IS gray (spray coating) (film thickness 30 ~ (40 μm, dry for 3 hours) (3) Elastic urethane coating: Ureol RIM PD-19
0 (Dedicated sprayer) (2500 μm film thickness, 5 minutes drying) Ureol RIM (PD-190) solidification drying time is 3
It is a minute, and the main agent / curing agent is separately pressure-fed and sprayed while using the special spray machine “TOMAC H-2000” while mixing the two liquids.

2. In the case of "Techtan 98SS" (manufactured by US Technical Urethane Co., Ltd.) (1) Test plate base material adjustment: blast treatment (Sa2.5) (2) Primer paint: Techgrip M-1 (spray coating) (film thickness 10 to 20 μm, Dry 20
Min) (3) Elastic urethane coating: Tectane 98SS (spray coating) (film thickness 2000 μm, drying 16 hours) Comparative Examples 1 to 8 A general-purpose anticorrosion coating was used as the coating, and other points were the same as in the example.

Performance Test Performance tests of the coating films of Examples and Comparative Examples were conducted, and the test results are summarized in Table 2.

[0013]

[Table 2] In Table 2, the anticorrosion performance was measured according to JIS K 6911. Other test items were measured visually.

As is clear from this table, it is recognized that the coating films of the Examples are superior to those of the Comparative Examples in all items.

[0015]

Since the coating composition according to the present invention is composed of a liquid urethane resin, it has the following effects.

A film having an arbitrary thickness can be formed by spray coating on the surface of the object to be coated, and long-term insulation and corrosion resistance (corrosion resistance) can be obtained.

Since the formed dry coating film has rubber-like elasticity, a) the elongation is high (400 to 500%), and it can withstand bending deformation of the coated object, collision impact, etc. B) Even if marine organisms adhere to the coating film in the sea, no damage such as biting of the coating film by marine adherent organisms, especially barnacles, is observed at all, and c) the coating film easily deforms and adheres. The aquatic organisms can be easily removed by impact, and d) the coating film is resistant to impact and abrasion, so it is not damaged even when mechanically removing organisms, and repair coating is not required.

Claims (1)

[Claims] 1. A coating composition for preventing damage by marine attached organisms, which is composed of a liquid urethane resin.