JPS6239629B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an underwater antifouling paint. More specifically, the present invention relates to an underwater antifouling paint that forms a film with excellent antifouling properties over a long period of time on ship bottoms, marine structures, seawater inlet pipes, and the like. Many types of substances are already known as antifouling agents used in paints. However, with emphasis on safety for the human body, cuprous oxide, tributyltin compounds, triphenyltin compounds, zinc dialkyldithiocarbamates, tetraalkyldithiocarbamates,
Tetraalkylthiuram dithiosulfide etc. are mainly used. These compounds are used as a mixture in a color vehicle such as a combination of chlorinated rubber, vinyl chloride resin, or drying oil-modified phenol resin and rosin. In general, the antifouling property of a coating film is exerted by the gradual elution and diffusion of the antifouling agent contained in the paint or its decomposition products from the coating film into the sea or water. The elution mechanism can be roughly divided into the following two modes. One form of this is to mix cuprous oxide as an antifouling agent at a high concentration in a paint that uses a water-resistant resin that does not contain rosin and is capable of forming a film (for example, vinyl chloride resin) as a color vehicle. This is a so-called insoluble type in which cuprous oxide is continuously eluted from the paint film over a long period of time by utilizing its solubility in water. In this type, when the content of cuprous oxide in the paint is low, the amount of cuprous oxide eluted during immersion in seawater decreases in a short period of time, and the sustainability of the antifouling effect is extremely reduced. In other words, this type of paint generally requires a large amount of antifouling agent to be incorporated into the paint, and as a result, for example, cuprous oxide tends to precipitate during storage and cause hard caking, and also makes it difficult to apply during the painting process. In addition to impairing the properties of the paint, it also has defects such as a brittle paint film, poor adhesion, and is prone to cracking and peeling.Coupled with the cost of the paint, it is rarely used these days. Another embodiment is a paint having a so-called soluble matrix type elution mechanism, which is made by using rosin as the main film-forming component and adding an antifouling agent such as cuprous oxide to the rosin. In this type of paint, rosin gradually dissolves from the surface of the paint film in seawater as a matrix component, and as a result, the antifouling agent is constantly exposed on the surface of the paint film, dissolves into the seawater, and exhibits antifouling properties. do. However, although this method can also be expected to improve the durability of the antifouling effect to some extent compared to the former, it will only last for about a year at most. As mentioned above, using rosin as a color vehicle in antifouling paints is effective in improving the sustainability of the antifouling effect, but the film obtained from rosin is extremely fragile and has poor water resistance, so it is difficult to use as a paint film. Performance (particularly strength) was low, and wear and tear in water was also high. Therefore, in order to improve the strength of the paint film, a small amount of resin, oil, or plasticizer that can form a film is added, but this does not satisfy both the sustainability of the antifouling effect and the durability of the paint film. The reality is that we are not getting anything. The reason for this is that if a sufficient amount of oil or resin is added to give the paint film strength and durability, the stain resistance of the paint film will be extremely low from the beginning, and its effectiveness as an antifouling paint will be diminished. This is because it does not perform well. Furthermore, conventional paints have had the problem of reduced antifouling effects due to deterioration of the paint film in areas exposed to sunlight near the water line due to ultraviolet rays. The object of the present invention is to improve or eliminate the deficiencies of conventional antifouling paints as described above, and to provide an underwater antifouling paint that has a long duration of antifouling effect and high film strength. be. That is, the present invention provides an underwater antifouling paint containing a color vehicle and an antifouling agent, in which the color vehicle is a copolymer of a fluoroolefin and a monomer containing a hydroxyl group or a group convertible to a hydroxyl group. contains a fluorine-containing polymer having a basic hydroxyl group and a polyvalent isocyanate, and the proportion of the antifouling agent to 100 parts by weight of the color vehicle is
It relates to an underwater antifouling paint characterized in that it contains 10 to 350 parts by weight. In the underwater antifouling paint of the present invention, it is important from the viewpoint of curability that the fluorine-containing polymer used as the vehicle component contains a hydroxyl group. That is, the presence of a hydroxyl group allows curing at room temperature by allowing a polyvalent isocyanate to coexist. Such polymers include copolymer types produced by copolymerization of various fluoroolefins and hydroxyl group-containing monomers, and copolymer types produced by hydrolyzing fluorine-containing polymers containing ester groups or halide groups. The resulting hydrolyzed type is used. More specifically, copolymer types include various copolymers containing hydroxyalkyl vinyl ether, allyl alcohol, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, etc. as comonomers, and hydrolyzable types include carboxyl Examples include those obtained by hydrolysis of fluorine-containing polymers containing units based on vinyl acid or allyl carboxylate. Therefore, in the present invention, ease of acquisition,
In view of the properties of the coating film, the above-mentioned copolymer type can be preferably employed, and in particular, for the same reason,
Fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether and hydroxyalkyl vinyl ether as essential constituents in proportions of 40 to 60 mol%, 5 to 45 mol%, 4 to 45 mol% and 3 to 15 mol%, respectively, preferably 45 to 55 mol%, respectively. Preferably, those containing mol%, 10 to 30 mol%, 10 to 35 mol%, and 5 to 13 mol% can be employed. Among such suitable copolymers, those having too low a fluoroolefin content are not only unfavorable from the viewpoint of weather resistance, but also cause problems in production.
Also, those containing too high a fluoroolefin content are also difficult to manufacture. On the other hand, if the cyclohexyl vinyl ether content is too low, the hardness when formed into a coating film is undesirable, and if the alkyl vinyl ether content is too low, the flexibility is undesirable. In addition, if the hydroxyalkyl vinyl ether content is too high, the solubility of the copolymer will change and it will only dissolve in certain substances such as alcohols, which will only limit its applicability as a solution-type paint base. This is undesirable because it reduces the flexibility of the cured coating film and reduces the gelation time (pot life) in the presence of the curing agent, significantly impairing the workability of the coating material. If the content is too low, the effect of improving curability is lost, resulting in an increase in curing time, a decrease in the solvent resistance and stain resistance of the cured coating, and furthermore, the adhesion with the undercoat, etc. This is not preferable because it causes disadvantages such as loss of quality. In the preferred copolymer described above, perhaloolefin, particularly chlorotrifluoroethylene or tetrafluoroethylene, is preferably employed as the fluoroolefin. Further, as the alkyl vinyl ether, those containing a linear or branched alkyl group having 2 to 8 carbon atoms, particularly those in which the alkyl group has 2 to 4 carbon atoms, are preferably employed. Note that the fluoroolefin and the alkyl vinyl ether are not limited to being used alone, but may also be used in the form of a mixture of two or more types. Further, the copolymer may contain units based on comonomers other than the above-mentioned four essential constituents in an amount not exceeding 30 mol%. Such comonomers include olefins such as ethylene, propylene, and isobutylene, haloolefins such as vinyl chloride and vinylidene chloride, unsaturated carboxylic acid esters such as methyl methacrylate, vinyl acetate, n
- Vinyl carboxylates such as vinyl butyrate can be exemplified. In the present invention, the fluorine-containing polymer has an intrinsic viscosity of 0.05 to 2.0 dl/g, particularly 0.07 to 0.8 dl/g, as measured at 30°C in tetrahydrofuran in an uncured state.
It is preferable to adopt a medium-sized one. If the viscosity is too low, the mechanical strength will decrease, while if it is too high, when applied as a solution-type paint, the solution concentration will have to be lowered due to the viscosity, and the workability will be impaired. Both are undesirable. In the present invention, the polyvalent isocyanate is a polyvalent isocyanate having two or more isocyanate groups in one molecule, such as ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, m-phenylene diisocyanate, etc. Nylene diisocyanate, p-phenylene diisocyanate, 2,4-tolylene-
Diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4, Polyhydric isocyanates such as 4'-diphenylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, isophorone diisocyanate, lysine isocyanate and excess of said isocyanate compounds, such as ethylene glycol, propylene glycol, 1,3-butylene glycol , neopentyl glycol, 2.
Difunctional or higher-functional polyols obtained by addition reaction with low-molecular-weight polyols such as 2,4-trimethyl-1,3-pentanediol, hexamethylene glycol, cyclohexanedimethanol, trimethylolpropane, hexanetriol, glycerin, and pentaerythritol. Examples include polyvalent isocyanates, polyvalent isocyanates having a Biuret structure, and polyvalent isocyanates having an allophanate bond. Among the polyvalent isocyanates, non-yellowing diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate and adducts thereof are particularly useful. The mixing ratio of the fluorine-containing polymer and the polyvalent isocyanate is (hydroxyl group in the fluorine-containing polymer)/(isocyanate group in the polyvalent isocyanate) = 1/1.3.
The range of 1/0.5 to 1/0.5 (equivalent ratio) is preferable. Incidentally, in order to promote the reaction between the fluorine-containing polymer and the polyvalent isocyanate, it is also possible to add a known catalyst such as dibutyltin dilaurate. In the present invention, it is also a preferred embodiment to add rosin to the vehicle containing the fluorine-containing polymer and polyvalent isocyanate for the purpose of controlling the elution rate of the antifouling agent component. It is also possible to add organotin polymers which have a similar function and also act as antifouling agents themselves. Examples of the organic tin polymer include polymers such as poly(tributyltin acrylate), poly(tripropyltin acrylate), poly(tributyltin methacrylate), and poly(tripropyltin methacrylate). In this case, the amount of rosin or organotin polymer used is approximately 20/80 to 80/20 (wt%) and 99/1 to 10/90, respectively, relative to [fluorine-containing polymer + polyvalent isocyanate]. (% by weight) is preferable. In the present invention, as the antifouling agent, those used in general antifouling paints are used. Examples include cuprous oxide, triphenyltin compounds (e.g., triphenyltin hydroxide, triphenyltin acetate, triphenyltin chloride, etc.), tetramethylthiuram sulfide, zinc methyldithiocarbamate, tributyltin compounds (e.g., tributyltin fluoride, tributyltin In some cases, in addition to mercury and arsenic compounds such as mercury oxide and arsenite, polymeric substances such as organotin polymers may also be used. The above antifouling agents may be used alone or as a mixture of two or more. The blending ratio of the antifouling agent and the color vehicle is 10 to 350 parts by weight of the antifouling agent to 100 parts by weight of the vehicle (solid content), and the amount of the antifouling agent mixed is 10 parts by weight. If the amount is less than 350 parts by weight, the antifouling paint will not exhibit sufficient effect, and if it is added in an amount exceeding 350 parts by weight, the strength and durability of the coating film will decrease, which is not preferable. The antifouling paint of the present invention contains a solvent, and if necessary, a colored pigment, an extender pigment, a flat filler such as flake glass, and other dispersants, a suspending agent, a viscosity modifier, a leveling agent, and an anti-gelling agent. , an ultraviolet absorber, etc. can be added as appropriate. The objects to be coated with the paint of the present invention may be coated with oil-based anti-rust paints, alkyd resin-based anti-rust paints, zinc-rich paints, etc., epoxy resin-based paints, urethane resin-based paints, etc., if necessary. It may be undercoated with a synthetic resin paint or the like. When applying the coating material of the present invention, it is applied onto the object to be coated by a conventional method such as brushing, spraying, or rolling so that the dry film thickness is usually about 50 to 300 microns. The coating film obtained in this way not only functions as an antifouling agent, but also has a long-lasting antifouling effect as it is a film formed from a fluorine-containing polymer and a polyvalent isocyanate. The colorant creates a coating film with excellent durability. The details of the present invention will be explained below with reference to Examples. "Part" or "%" means "part by weight" or "% by weight"
It is shown with. Example 1 Contains units based on chlorotrifluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether and hydroxybutyl vinyl ether in proportions of 51.2 mol%, 17.1 mol%, 22.5 mol% and 9.1 mol%, respectively, and has an intrinsic viscosity (THF
Using a fluorine-containing quaternary copolymer with a ([η]) of 0.21 dl/g and a glass transition temperature (DSC under temperature increase of 10°C/m) (Tg) of 45°C, the following According to the composition, the antifouling paint used in the method of the present invention was created. Fluorine-containing copolymer 100 parts Handle 40 Cuprous oxide 100 Xylol 160 The above mixture was kneaded in a pot mill for 24 hours to obtain an antifouling paint main ingredient. Add 8 parts of hexamethylene diisocyanate and 15 parts of dibutyltin dilaurate to the main ingredient immediately before use.
A curing agent consisting of x10 ^-7 parts was mixed to obtain an antifouling paint (A). This paint was subjected to a comparative test described below. Example 2 An antifouling paint was prepared using the fluorine-containing copolymer of Example 1. Rosin 100 parts Fluorine-containing copolymer (same as Example 1) 100 Petal pattern 60 Cuprous oxide 80 Flake glass [Nippon Glass Fiber Co., Ltd. product name: CF-
150] 100 Xylol 160 Using the above mixture, an antifouling paint (B) was prepared in the same manner as in Example 1. Example 3 50.8 mol%, 16.9 mol%, 22.8 mol% and 9.5 mol% of units based on tetrafluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether and hydroxybutyl vinyl ether, respectively
Contains in mol%, [η] is 0.23dl/g, Tg
A fluorine-containing quaternary copolymer having a temperature of 27°C was used. Fluorine-containing copolymer 100 parts Poly(tributyltin acrylate) 100 Valve pattern 100 Cuprous oxide 200 Xylol 240 An antifouling paint (C) was obtained in the same manner as in Example 1 using the above mixture. Example 4 An antifouling paint (D) was prepared in the same manner as in Example 1 using the following formulation. Fluorine-containing copolymer (same as Example 3) 100 parts Poly(tributyltin acrylate) 100 Valve handle 100 Cuprous oxide 200 Tributyltin fluoride 20 Flake glass (same as Example 2) 50 Xylol 260 Comparative example 1 part Rosin 30 Polymerized linseed oil 10 Petals 10 Cuprous oxide 30 Talc 20 Mineral spirits 20 The mixture was kneaded in a pot mill for 24 hours to obtain an antifouling paint (F). Comparative Example 2 Parts Rosin 30 Chlorinated Rubber 10 Chlorinated Paraffin 5 Cuprous Oxide 30 Talc 20 Mineral Spirits 20 A paint was prepared in the same manner as in Comparative Example 1, and an antifouling paint (G) was prepared.
I got it. Dry film thickness of zinc-rich primer using conventional method.
The object to be coated was a steel plate (JISG3141) that was coated and dried to a thickness of 75 microns, and then coated with epoxy resin paint to a dry film thickness of 200 microns and dried. Each of the antifouling paints obtained in Examples 1 to 4 and Comparative Examples 1 to 2 was spray-coated onto the above-mentioned objects to a dry film thickness of 100 microns, dried at room temperature for 10 days, and then subjected to a comparative test. provided. The results are shown in Table 1.

[Table] It is clear from the comparative test result table that the coating film obtained from the underwater antifouling paint of the present invention has better antifouling properties than the coating film obtained from the conventionally known antifouling paint composition. It lasted for a long time and caused little paint film deterioration.

Claims (1)

[Scope of Claims] 1. An underwater antifouling paint containing a color vehicle and an antifouling agent, wherein the color vehicle is a copolymer of a monomer containing a hydroxyl group or a group convertible to a hydroxyl group and a fluoroolefin. An underwater antifouling agent comprising a fluorine-containing polymer containing a hydroxyl group based on coalescence and a polyvalent isocyanate, and characterized in that the proportion of the antifouling agent to 100 parts by weight of the vehicle is 10 to 350 parts by weight. paint. 2 The fluorine-containing polymer is fluoroolefin 40~
60 mol%, cyclohexyl vinyl ether 5-45
mol%, alkyl vinyl ether 5-45 mol%,
Hydroxyalkyl vinyl ether 3-15 mol%
The underwater antifouling paint according to claim 1, which is a copolymer consisting of 0 to 30 mol% of other comonomers. 3. The underwater antifouling paint according to claim 2, wherein the fluoroolefin is chlorotrifluoroethylene and/or tetrafluoroethylene. 4. Claim 1, in which the color vehicle contains rosin or an organotin polymer in addition to a fluorine-containing polymer having a hydroxyl group and a polyvalent isocyanate;
The underwater antifouling paint according to any one of Items 2 and 3.