JPH04356567A - Antifouling coating composition - Google Patents

Abstract

PURPOSE:To prepare the title compsn. which gives a coating film exhibiting excellent antifouling properties for a long time by compounding a specific vehicle with a specific antifouling agent consisting of a copper alloy powder. CONSTITUTION:The title compsn. is prepd. by compounding a vehicle consisting of a hydrophobic resin (e.g. a vinyl resin), a slightly sol. resin (e.g. rosin), and a hydrophilic resin (e.g. PVA) with an antifouling agent consisting of a copper alloy powder contg. 3-25wt.% Ni and/or Mn and 0.1-1.5wt.% iron.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater antifouling coating composition. More specifically, an underwater antifouling paint composition containing copper alloy powder that can be applied to ship bottoms, underwater structures (structures used in seawater or freshwater such as port facilities, oil drilling rigs, and bridge piers), or seawater introduction pipes. relating to things.

0002

2. Description of the Related Art In general, it is known that when marine organisms adhere to the bottom outer panel of a ship, it results in wasted propulsion energy and impedes the operation of the ship. Furthermore, it has been found that organisms adhere to the surface of marine structures, damaging the anticorrosive coating layer, and as a result, the service life of the structure is significantly shortened. Furthermore, there have been problems such as the accumulation of attached organisms on seawater inlet pipes, etc., which significantly deteriorates their original functions.

[0003] As described above, the adhesion of marine organisms causes extremely great damage industrially, so it is necessary to avoid such adhesion as much as possible. As a countermeasure, underwater antifouling paint compositions containing various antifouling agents are used. has been done.

[0004] Conventional antifouling paint compositions use, for example, a water-resistant resin capable of forming a film such as vinyl chloride resin as a color vehicle, and a copper compound such as cuprous oxide or copper copper, a copper metal, or an organic Compositions containing antifouling agents such as tin compounds, or organic tin polymer-type antifouling paints whose main component is tin, an antifouling component, chemically combined with a film-forming resin are used. .

However, the former type, that is, the coating film obtained from an antifouling paint composition containing vinyl chloride resin, chlorinated rubber, etc. as a color vehicle and blending cuprous oxide, copper copper, metal copper, etc.,
Since the resin used as a color vehicle is hydrophobic, only the antifouling agent present in the very surface layer of the paint film is effective, and the dissolution duration of the antifouling agent itself is short, so the coating The antifouling property of the membrane could only last for about one year, which was unsatisfactory.

Furthermore, products containing organotin are currently mainstream due to their excellent antifouling properties, but the impact of highly toxic organotin compounds on the environment and their accumulation in living organisms have become a problem, and the Ministry of Transport has already approved them. A notification has been issued regulating its use. Therefore, it is inevitable that antifouling paint compositions containing organotin will soon become completely unusable, and there is a desire to develop an alternative antifouling paint composition that has long-term durability.

[0007] From the above-mentioned viewpoint, various improvements have been attempted in the past. For example, an antifouling material consisting of a water-absorbing elastomer composition and copper or copper alloy powder (Japanese Patent Application Laid-open No.
No. 201862), and an underwater antifouling paint composition using vinyl resin or chlorinated rubber as a color vehicle and copper alloy powder as an antifouling agent (Japanese Patent Publication No. 63-55547). However, since the color vehicle is not hydrophilic, long-term stain resistance cannot be expected.

[0008] Examples of using a hydrophilic resin as a color vehicle include, for example, antifouling paints that use a color vehicle that uses a combination of a water-insoluble resin and a water-soluble resin, and cuprous oxide or an organic tin compound (unexamined patent application). Antifouling paint compositions using a color vehicle that uses a combination of a specific water-soluble resin such as methyl vinyl ether or N-vinylpyrrolidone and a slightly hydrolyzable acrylic copolymer (Japanese Patent Application Laid-Open No. 131285/1982) However, in the former, a water-insoluble resin remains after the water-soluble resin dissolves, and subsequent elution of the antifouling agent becomes poor, and in the latter, the physical properties of the coating film are not sufficient. Blistering, peeling, etc. were likely to occur, and in both cases, long-term stain resistance and durability could not be expected.

[0009]

[Problems to be Solved by the Invention] In view of the above circumstances, the present inventors have developed an antifouling film that does not contain organic tin compounds and can form a coating film that maintains excellent antifouling performance over a long period of time. As a result of extensive research into stain paint compositions, we have arrived at the present invention.

[0010] That is, an object of the present invention is to provide an antifouling coating composition that has extremely excellent antifouling performance and is capable of forming a coating film that can maintain this performance for a long period of time.

[0011]

[Means for Solving the Problems] The present invention provides (a) a hydrophobic resin (A), a slightly soluble resin (B) and a hydrophilic resin (C).
), and (b) 3 to 25% by weight of nickel and/or manganese as an antifouling agent, and 0.1% of iron.
It relates to an antifouling paint composition comprising copper alloy powder containing ~1.5% by weight.

The hydrophobic resin (A) as the color vehicle used in the antifouling paint composition of the present invention may be a vinyl resin (vinyl chloride resin, vinyl chloride resin, etc.) which is usually used in antifouling paints. -vinyl isobutyl ether copolymer resin, vinyl chloride-vinyl acetate copolymer resin, etc.), chlorinated rubber,
Examples of the slightly soluble resin (B) include rosin, and examples of the hydrophilic resin (C) include polyvinyl alcohol, polyvinyl methyl ether, Examples include polyvinylethyl ether and methylolated melamine resin. Any of these can be used alone or as a mixture of two or more.

In the present invention, the hydrophobic resin (A), the slightly soluble resin (B), and the hydrophilic resin (C) each have an elution amount of (A) less than 0.1% by weight/day in seawater at 20°C. ,(
B) 0.5 to 2% by weight/day, and (C) preferably more than 2% by weight/day.

[0014] The elution amount for the seawater at 20°C is as follows:
For example, each resin solution is applied to one side of a 25 mm x 75 mm glass plate, air dried for 3 days, vacuum dried at 40°C to a constant weight, and then immersed in seawater in a 100 cc peaker for 10 days. The amount of elution per day can be determined by lifting the sample, drying it under vacuum at 40° C., determining the weight loss, and calculating the elution amount per day.

Further, in the coating composition of the present invention, each of the resins has a ratio of A/B=5/1 to 1/5, and (A+B)/C=9.
It is preferable to use it at a weight ratio of /1 to 3/7.

In the present invention, if a hydrophilic resin is not used as a color vehicle, the effect of preventing the adhesion of slime is insufficient, and the supply of copper ions, which exhibit the antifouling effect, is insufficient from the surface layer of the coating film. Since it is limited, long-term stain resistance cannot be expected.

[0017] By using a hydrophilic resin in combination, the antifouling agent is eluted from inside the coating film, so that the antifouling property is exhibited for a long period of time, but the hydrophilic resin itself dissolves in water. Therefore, if only the hydrophobic resin remains after the hydrophilic resin has eluted, it will form an uneven film and make it difficult for the antifouling agent to elute. However, by using a slightly soluble resin in combination, the elution of the resin component can be prevented. It can be made uniform, a new film always appears without leaving an uneven film, and the elution sustainability of the antifouling agent is also improved.

The copper alloy powder as an antifouling agent used in the antifouling paint composition of the present invention contains 3 to 25% by weight of at least one metal selected from nickel and manganese and 0.1% by weight of iron. It contains ~1.5% by weight, and the remaining composition is mainly copper-based.

The shape of the copper alloy powder referred to in the present invention is granular,
Includes all fibrous or flat powders.

[0020] In the copper alloy powder, the content of at least one metal selected from nickel and manganese is 3.
If it is less than % by weight, the copper alloy powder will have a greater tendency to oxidize, and therefore the antifouling effect cannot be expected to last long. Moreover, in the initial stage of immersion in seawater, the amount of copper ions eluted becomes excessive, leading to wastage of copper alloy, and as a result, the durability of the antifouling effect of the coating film decreases.

On the other hand, if the amount of nickel and/or manganese exceeds 25% by weight, the copper content as an antifouling agent will inevitably decrease, resulting in a decrease in the antifouling effect of the coating film.

Further, the iron component must be contained in a range of 0.1 to 1.5% by weight in order to homogenize the structure of the copper alloy and to ensure uniform solubility of copper.

[0023] Further, the copper alloy powder may be granular with an average particle size of 50μ or less, flat particles with an average length of 10 to 200μ and an average thickness of about 2 to 10μ, or Average diameter 2~15μ, average length 10~200
It is preferable to have a fibrous shape of about μ.

In any case, by making the copper alloy powder of the present invention have a specific composition as described above, the elution of copper ions can be controlled and the antifouling effect can be sustained.

In the coating composition of the present invention, the copper alloy powder is contained in an amount of 100 to 9 parts by weight based on 100 parts by weight of the solid content of the vehicle.
It is preferred to use it in a proportion of 50 parts by weight, particularly preferably 200 to 900 parts by weight.

Within the above range, if the amount of copper alloy powder used is less than 100 parts by weight, it is difficult to achieve the desired antifouling effect. On the other hand, if it is used in an amount exceeding 950 parts by weight, the strength of the coating film tends to decrease and defects such as peeling tend to occur, which is not very preferable.

The antifouling paint composition of the present invention can form a coating film having sufficient antifouling properties by itself, but if necessary, other antifouling agents such as cuprous oxide, cuprous Rodan, manganic acid may be added. needs ethylene bisdithiocarbamate, zinc dimethyldithiocarbamate, 2-methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine,
2,4,5,6-tetrachloroisophthalonitrile, N
, N-dimethyldichlorophenylurea, zinc ethylene bisdithiocarbamate, 4,5-dichloro-2-N-
Octyl-3(2H) isothiazolone, N-(fluorodichloromethylthio)-phthalimide, N,N-dimethyl-N'-phenyl-(N-fluorodichloromethylthio)sulfamide, tetramethylthiuram disulfide, 2,4,6- Trichlorophenylmaleimide, 2-
One or more types of pyridinethiol-1-oxide zinc salts may be mixed.

In this case, 100 parts by weight of solid color vehicle, 100 to 800 parts by weight of copper alloy powder, and 0 to 800 parts by weight of other antifouling agent.
Preferably, it is used in a proportion of 250 parts by weight.

[0029] When the above-mentioned other antifouling agents are used in an amount exceeding 250 parts by weight, it is not preferable because the strength of the coating film tends to decrease.

In the antifouling paint composition of the present invention, in addition to the above-mentioned components, if necessary, a coloring pigment; an extender pigment; a plasticizer;
Various components commonly used in paints can be added and mixed, such as an elution aid for antifouling agents; a solvent; and various other additives (antifoaming agents, antisettling agents, leveling agents).

The antifouling paint composition of the present invention can be prepared as a single liquid by mixing and dispersing the color vehicle, copper alloy powder, and other components all at once or in parts using ordinary paint manufacturing equipment (ball mill, disper, etc.). It can be prepared as a mold paint.

[0032] Alternatively, the coating components may be prepared by dividing them into two-component types and mixing and dispersing them immediately before use.

The antifouling paint composition of the present invention thus prepared can be applied to ships as it is or after adjusting the viscosity with a solvent, usually by airless spray coating, but in some cases by roller coating, brush coating, or double gun coating. It is applied to marine structures, etc. with a dry film thickness of about 30μ to 300μ. The coating film obtained from the antifouling paint composition of the present invention having the above-mentioned structure has excellent antifouling properties and can maintain its antifouling properties for a long period of time.

[0034]

[Examples] The details of the present invention will be explained below with reference to Examples and Comparative Examples. "Part" or "%" means "part by weight" or "% by weight"
”.

Examples 1 to 8 and Comparative Examples 1 to 7 Antifouling coating compositions of the present invention and comparative examples were obtained according to the formulations shown in Tables 1 and 2.

[0036]

[Table 1]

[0037]

[Table 2]

The coating composition was prepared by first kneading the components except the copper alloy powder in a sand mill to a particle size of 60 μm using method A, and then mixing and dispersing the copper alloy powder in a stirrer.

The coating composition obtained as described above was applied by air spray to a dry film thickness of about 100 μm, and was subjected to a comparative test. The results are shown in Table 3.

[0040]

[Table 3]

[0041] Antifouling property evaluation method: PVC resin plate (30
0 x 100 x 2 mm), the antifouling paint compositions of Examples and Comparative Examples were air-sprayed to a dry film thickness of 100μ, and after drying at room temperature for 4 days, they were painted under the sea near Toba City, Mie Prefecture. It was immersed at a depth of 0 to 30 cm, and the state of attachment of organisms was observed over time. Slime 4: Not attached at all 3: Very thinly attached 2: Moderately attached 1: Thickly attached Shellfish, algae Adhering area (%)

[0042]

[Effects of the Invention] It is clear from Table 3 that the coating film obtained from the antifouling paint composition of the present invention exhibited excellent antifouling properties, with almost no adhesion of organisms observed for more than 30 months. A system that does not use a hydrophilic resin (Comparative Example 1), a system that uses an antifouling agent other than the one according to the present invention (Comparative Examples 2 and 5), and a system that uses a copper alloy powder that is outside the scope of the present invention (Comparative Example 3). ), and the system (Comparative Example 4) in which no slightly soluble resin was used, not only slime but also shellfish and algae adhered at an early stage and in large quantities.

[0043] This means that by using the combination of color vehicles and copper alloy powder of a specific composition in the present invention, the antifouling agent can be eluted in a very controlled amount due to the synergistic effect of the combination of the two. It shows.

Claims (3)

[Claims] Claim 1: (a) a color vehicle consisting of a hydrophobic resin (A), a slightly soluble resin (B) and a hydrophilic resin (C);
b) An antifouling paint composition comprising copper alloy powder containing 3 to 25% by weight of nickel and/or manganese and 0.1 to 1.5% by weight of iron as an antifouling agent. [Claim 2] (a) 100 parts by weight of a color vehicle and (b)
The antifouling coating composition according to claim 1, comprising 100 to 950 parts by weight of copper alloy powder. [Claim 3] Hydrophobic resin (A), slightly soluble resin (B)
) and the hydrophilic resin (C) are those whose elution amount in seawater at 20°C is (A) less than 0.1% by weight/day, (B) 0.
The antifouling paint composition according to claim 1 or 2, wherein the amount of the antifouling coating composition is 5 to 2% by weight/day, and (C) exceeds 2% by weight/day.