JPH08324481A - Ship's bottom coating material - Google Patents

Abstract

PURPOSE: To provide a ship's bottom coating material having no possibility of environmental pollution, for decreasing a value of resistance of flowing water of a hall, having high preventing properties of aquatic organism sticking, and excellent in durability. CONSTITUTION: A water swelling agent is mixed to an elastic high polymeric material such as a rubber raw material. It is desirable that the rubber raw material is vulcanized, it is desirable that the water swelling agent of 5 to 100 parts by weight is mixed to the rubber raw material of 100 parts by weight, and acrylic acid-polyvinyl alcohol copolymer is preferable as the water swelling agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ship bottom coating material that reduces the running water resistance value of a ship by coating the hull, especially the ship bottom. Further, in addition to the above-mentioned function, the ship bottom is protected from aquatic life such as shellfish. The present invention relates to a ship bottom coating material that also has an effect of preventing adhesion.

[0002]

2. Description of the Related Art Conventionally, various paints have been developed to reduce the running water resistance value of a ship. For example, there is a paint or the like in which the surface of the coating film is peeled off little by little and the surface smoothness is always maintained to reduce the running water resistance value. Also,
Further, it is known that various aquatic organisms adhere to the hull of an underwater portion of the ship to deteriorate the hull and increase the resistance of the hull to fluid. For example, there is a problem that marine organisms such as barnacles, mussels, pearl oysters, bryozoans, sponges, ascidians and aquatic organisms such as algae such as diatoms and seagrass deteriorate their function and deteriorate surface properties. Therefore, various techniques for preventing the adhesion of these aquatic organisms have been proposed.

As a paint having an action of preventing adhesion of aquatic organisms, an attempt has been made to prepare an antifouling paint by blending a water-swelling polymer with an organic binder such as rubber or synthetic resin.
No. 775, it is not suitable for use on an open ocean vessel or the like where it is difficult to maintain the paint layer for a long period of time because of the problem that the coating film thickness is thin and the effect persistence is lacking.

Although these raw materials containing an organic solvent are small in number, they are dispersed in the ocean and are not environmentally preferable for use in the ocean and rivers.

In addition, as an aquatic organism adhesion preventing material, Japanese Patent Laid-Open No. 4-69307 discloses an antifouling material in which an antifouling paint contains dichlorophenyl isothiocyanates and a copper or tin compound. No. 5-339113 proposes a material for preventing adhesion of marine organisms, which is obtained by vulcanizing a rubber composition containing alkylisothianates.

However, in the method of incorporating isothiocyanates repelled by aquatic organisms into paints and rubber compositions, there is a problem that the repellent is always released into the sea and its effect decreases over time. Had the drawback that it could pollute the ocean.

[0007]

As described above, all the materials have a problem that they may cause marine pollution, and a technique for reducing the running water resistance value of the hull without the problem of pollution is desired. Was there.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to reduce the running water resistance value of a hull and to prevent aquatic organisms from adhering without fear of environmental pollution. It is intended to provide a ship bottom coating material having high durability and excellent durability.

[0009]

The bottom coating material of the present invention is characterized by comprising an elastic polymer material mixed with a water swelling agent.

Further, the present invention is preferably the ship bottom coating material as described above, wherein the water swelling agent is an acrylate-
It is characterized by being a polyvinyl alcohol copolymer.

The present invention will be described in detail below. The water swelling agent used in the present invention includes an organic water swelling material called an superabsorbent resin and an inorganic swelling material, which is swollen by absorbing water and is a polymer substance capable of retaining water in the molecule. It does not include a water-soluble polymer.

Examples of water swelling agents that can be used include polymers such as polyacrylic acid salt-based, polyethylene oxide-based, vinyl acetate copolymer-based, acrylic acid graft copolymer-based, and the like. A copolymer of polyacrylic acid such as sodium and polyvinyl alcohol,
Crosslinked sodium polyacrylate, vinyl acetate-methyl acrylate copolymer, vinyl acetate-maleic anhydride copolymer saponified product, isobutylene-maleic anhydride copolymer crosslinked product, polyacrylonitrile hydrolyzate, starch-acrylonitrile graft Copolymer saponified product, starch-acrylic acid graft copolymer, polysaccharide-acrylic acid graft copolymer, carboxymethyl cellulose cross-linked to the reaction product of cellulose and monochloroacetic acid, polyethylene oxide cross-linked product, polyvinyl alcohol cross-linked product ,
Silica-based or silicate-based inorganic swelling agents such as white carbon and bentonite can be used. These water swelling agents can be used alone or in admixture of two or more. Of these, polyacrylic acid-polyvinyl alcohol copolymer, cross-linked sodium polyacrylate,
It is preferable from the viewpoints of anti-adhesion effect, safety and easy availability.

The amount of the water swelling agent to be blended with the elastic polymer material is not particularly limited, but is preferably 5 to 100 parts by weight, preferably less than 5 parts by weight, based on 100 parts by weight of the elastic polymer material. And the effect of lowering the running water resistance value tends to be insufficient, and when it exceeds 100 parts by weight, the swelling rate of the ship bottom coating material increases and it is difficult to sufficiently hold the water swelling material, and the durability of the effect decreases. There is a tendency. From the viewpoint of the effect of lowering the running water resistance value, the compounding amount is further preferably 5 to 50 parts by weight, more preferably 10 to 30 parts by weight.

The elastic polymer material containing the water swelling agent is
There is no particular limitation, and general-purpose rubber raw materials such as natural rubber or other synthetic rubber, thermoplastic elastomers such as styrene elastomer and olefin elastomer, and blends of rubber and plastic can be preferably used.

Above all, it is preferable to use a rubber raw material such as synthetic rubber from the viewpoint of durability and versatility. Examples of the synthetic rubber used here include polyisoprene rubber such as cis-1,4-polyisoprene, low cis-1,4-polybutadiene, polybutadiene rubber such as high cis-1,4-polybutadiene, and styrene-butadiene copolymer. Union (SBR),
Ethylene-propylene-diene copolymer (EPDM),
Examples thereof include chloroprene, halogenated butyl rubber, ethylene-vinyl acetate copolymer, acrylic rubber, silicone rubber, nitrile rubber, fluororubber and acrylonitrile-butadiene rubber (NBR). These natural rubbers and synthetic rubbers may be used alone or in combination of two or more, but among them, from the viewpoint of processability, natural rubber, cis-1,4-polyisoprene, It is preferable to use a styrene-butadiene copolymer, low cis-1,4-polybutadiene, and high cis-1,4-polybutadiene.

As a method of blending the water-swelling agent with the elastic polymer material, a method of uniformly mixing the elastic polymer material and the water-swelling agent using a Banbury mixer or the like is used when a rubber raw material is used. A method of adding a water swelling agent and uniformly kneading the vulcanized rubber raw material and the auxiliary agent when using a Banbury mixer or the like can be mentioned.

When a rubber raw material is used as the elastic polymer material as described above, a rubber raw material containing a water swelling agent is used.
It is preferable to obtain a ship bottom coating material by vulcanizing by adding a vulcanizing agent and heating. As the vulcanizing agent added at this time, sulfur can be mentioned.
0.1 to 5 parts by weight, preferably 1 to 100 parts by weight
2 parts by weight. If it is less than 0.1 parts by weight, the tensile strength of the vulcanized rubber will be poor, and if it exceeds 5 parts by weight, rubber elasticity will be lost.

As the vulcanizing agent other than sulfur, a metal oxide, an organic peroxide, an organic sulfur-containing compound, a reactive resin or the like may be used or a combination thereof may be used. It is determined by the type of rubber raw material.

The ship bottom coating material of the present invention is preferably vulcanized after mixing a rubber raw material with a water swelling material. Vulcanization is performed by adding a vulcanizing agent to the rubber raw material mixture as described above, and heating after adding the vulcanizing agent is preferable from the viewpoint of durability of the obtained ship bottom coating material. Heating
120 to 1 so as not to affect the compounded water swelling agent
It is preferably carried out at 70 ° C. A compound which is not vulcanized is not preferable because it is inferior in strength and the aquatic organism adhesion performance is not sufficiently obtained.

In the present invention, the unvulcanized composition is molded into a desired shape, for example, a sheet having an appropriate size, and then vulcanized to have a shape suitable for the place where the bottom coating material is attached. Can be easily obtained.

Further, a vulcanization accelerator can be added to the anti-adhesion material of the present invention. The vulcanization accelerator that can be used in the present invention is not particularly limited, but preferably M
(2-mercaptobenzothiazole), DM (dibenzothiazyldisulfide), CZ (N-cyclohexyl-2-benzothiazylsulfenamide), and other thiazole-based vulcanizations such as DPG (diphenylguanidine) and other guanidine-based vulcanizations Accelerator, EU (ethylene thiourea), DEU
(Diethylthiourea) and other thiourea-based vulcanization accelerators, TT (tetramethylthiuram disulfide), T
Examples thereof include thiuram-based vulcanization accelerators such as S (tetramethylthiuram monosulfide), and the amount thereof is 0.1 to 5 parts by weight with respect to 100 parts by weight of the rubber raw material.
It is preferably 0.2 to 3 parts by weight.

In the present invention, in addition to these, antioxidants, fillers such as carbon black, silica, calcium carbonate, titanium oxide, etc., which can be compounded in usual rubber compositions, zinc oxide, stearic acid, antioxidants, ozone. An additive such as an anti-degradation agent may be blended within a range not hindering the purpose of the present invention in order to impart characteristics suitable for the purpose of use of the ship bottom coating material and the environment in which it is used.

The ship bottom coating material of the present invention is preferably prepared, for example, by mixing the raw material mixture obtained by kneading with a kneading machine such as a roll or an internal mixer so as to be suitable for the site where the material is used. After being formed into a sheet having various sizes, it is vulcanized to obtain a ship bottom coating material having a desired shape. This is attached to the entire portion of the hull located underwater, or a portion that contributes to the running water resistance value of the hull, such as the bow, bottom, and side surfaces. When the ship bottom coating material is attached to the hull, it is preferable to use a rubber-based room temperature curing adhesive or the like as the adhesive from the viewpoint of durability.

Further, the ship bottom coating material of the present invention is such that when the ship bottom is in a dry state such as when the hull is a dry dog, a mixture of the elastic polymer material and a water swelling agent is desired for the ship bottom. After being applied to the above-mentioned part, it may be cured to form a layer of the ship bottom coating material on the ship bottom. in this case,
The elastic polymer material used is a room temperature reaction type, for example,
It is preferably a vinyl chloride-based, urethane-based or rubber-based paint.

[0025]

EXAMPLES Next, the present invention will be described in detail with reference to specific examples, but the present invention is not limited to the following examples.

[Example] 1-1. Manufacture of ship bottom coating materials Elastic polymer materials and water swelling agents (1) to (6)
Was kneaded, and the vulcanizing agent (7) and the vulcanization accelerators (8) to (10) were added to form a sheet having a thickness of 0.5 mm to obtain a ship bottom coating material.

(1) CR (neoprene) 60 parts by weight (2) SBR 20 parts by weight (3) NR 20 parts by weight (4) Calcium carbonate 40 parts by weight (5) Silica 25 parts by weight (6) Water swelling agent (acrylic Sodium acid-polyvinyl alcohol copolymer: manufactured by Nippon Shokubai Kogyo KK, Aqualic CS: trade name 30 parts by weight (7) 0.2 parts by weight of sulfur (8) 2.5 parts by weight of magnesium oxide (9) Sulfurization accelerator (ditolylguanidine) 0.5 part by weight (10) Vulcanization accelerator (tetramethylthiuram disulfide) 1.0 part by weight 1-2. Evaluation of dissolution property The sheet-shaped ship bottom coating material obtained above was immersed in artificial seawater for 2.5 months, and it was confirmed whether or not the water swelling agent and the elastic polymer material were dissolved into the artificial seawater. No elution was observed even after 2.5 months.

1-3. Evaluation of running water resistance value After sticking the sheet-shaped ship bottom coating material obtained above to the ship bottom of the model hull using a rubber-based room temperature curable adhesive,
With a towing trolley installed in the experimental tank, towing at 3-5 knots,
The running water resistance value was evaluated.

As a comparative sample, a sample coated with a cuprous oxide paint was prepared as a comparative example, and the same evaluation was performed. The relative value of the running water resistance value of the example when the running water resistance value in the comparative example was 100 was determined, and the results are shown in Table 1 below.

1-4. Evaluation of Durability and Prevention of Adhesion to Aquatic Organisms The sheet-shaped bottom coating material obtained in the above is 30 cm × 3
The sample was cut into a piece of 0 cm and a thickness of 5 mm, which was fixed to a 1 m × 1 m canvas with bolts to give a sample for evaluation.

As a comparative sample, a sample coated with a cuprous oxide paint was prepared. Each of the samples was immersed in seawater for 12 months, and the durability and the state of adhesion of aquatic organisms were visually observed.

The evaluation criteria for observation are as follows: ◎ to ○
Indicates that there is no problem in practical use. (Durability) A: No deterioration is observed. ◯: Almost no deterioration is observed. X: A part peeled from the base material is seen.

(Aquatic organism adhesion prevention property) ⊚: Almost no adhesion of shellfish, seaweed and algae is observed. ○: Shellfish, seaweed, and algae are partially attached. X: Shellfish, seaweed, and algae are attached to one side.

Table 1 shows the above evaluation results.

[0035]

[Table 1]

The ship bottom coating materials of the examples of the present invention did not elute into seawater, and as shown in Table 1, the hull to which the ship bottom coating material was applied had a resistance against running water as compared to a ship without the application. The value was small, and only a small amount of algae adhered to the portion where the ship bottom coating material of the example was applied, no adhesion of shellfish was observed, and a small amount of algae adhered. On the other hand, the ship bottom coating material of Comparative Example has no problem in durability, but has no effect of preventing the adhesion of aquatic organisms, and therefore it was expected that the running water resistance value would further decrease with time.

[0037]

EFFECT OF THE INVENTION Since the ship bottom coating material of the present invention has the above-mentioned constitution, there is no fear of environmental pollution, and further, the running water resistance value of the hull is lowered, and the effect of preventing the adhesion of aquatic organisms and its durability are excellent. Have.

Claims (4)

[Claims] 1. A ship bottom coating material comprising an elastic polymer material mixed with a water swelling agent. 2. The ship bottom coating material according to claim 1, wherein 5 to 100 parts by weight of the water swelling agent is mixed with 100 parts by weight of the elastic polymer material. 3. The elastic polymer material is a rubber raw material,
The ship bottom coating material according to claim 1, wherein the water swelling agent is blended and then vulcanized. 4. The ship bottom coating material according to claim 1, wherein the water swelling agent is an acrylate-polyvinyl alcohol copolymer.