JPS58136666A - Underwater antifouling coating - Google Patents

Abstract

PURPOSE:To provide an underwater antifouling coating which is applied to ship bottom and marine structures and forms a film exhibiting an excellent antifouling effect for a long period, prepared by blending an antifouling agent into a specified vehicle. CONSTITUTION:The vehicle for the coating consists of a mixture of (1) fluorine- contg. polymer (e.g. copolymer of about 40-60mol% fluoro-olefin, about 5- 45mol% cyclohexyl vinyl ether, about 5-45mol% alkyl vinyl ether, about 3- 15mol% hydroxyalkyl vinyl ether and about 0-30mol% monomer other than the above) and (2) polyisocyanate (e.g. hexamethylene diisocyanate) in such a ratio that hydroxyl group/isocyanate group may be 1/1.3-1/0.5 by eq. The coating is prepared by blending 100pts.wt. said vehicle with 10-350pts.wt. antifouling agent (e.g. copper suboxide, tributyltin chloride).

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. With an emphasis on safety and safety for the human body, we use copper cuprous oxide, tributyltin compounds, triphenyltin compounds,
Zinc dialkyldithiocarbamates, tetraalkyldithiocarbamates, tetraalkylthiuram dithiosulfides, 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 determined by the antifouling agent contained in the paint or the decomposition products of the antifouling agent contained in the paint. or by gradual elution and diffusion into 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 paint's properties, it also causes defects such as brittle paint films, poor adhesion, easy cracking, and easy peeling.
1! , rarely used.

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 C1 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 and dissolves into the seawater, improving its antifouling properties. Demonstrate.

However, although this method can also be expected to improve the durability of the antifouling effect to some extent compared to the former, it is only after morning 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 severe.

Therefore, in order to improve the strength of the coating film, a small amount of resin, oil, or plasticizer that can form a coating is added.
The reality is that no product has been found that satisfies both the durability of the antifouling effect and the durability of the paint film.

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 often suffer from 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 defects of conventional antifouling paints as described above, and to provide an underwater antifouling paint with a long duration of antifouling effect and high film strength. It is.

That is, the present invention provides an underwater antifouling paint containing a color vehicle and an antifouling agent, wherein the vehicle contains a fluorine-containing polymer having a hydroxyl group and a polyvalent iso7anate, and the color vehicle The present invention relates to an underwater antifouling paint characterized in that the ratio of the antifouling agent to 100 parts by weight is 10 to 650 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,
Various types such as hydrolyzed type obtained by hydrolyzing a fluorine-containing polymer containing an ester group or a halide group, and a condensed type obtained by condensation of fluorinated diol and shrimp halohydrin 1. can be exemplified.

More specifically, copolymer types include various copolymers containing hydroxyalkyl vinyl ether, allyl alcohol, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, etc. as cochargers, and hydrolyzable types include carboxylic acid Examples include those obtained by hydrolysis of fluorine-containing polymers containing units based on vinyl or allyl carboxylate.

Therefore, in the present invention, the above-mentioned copolymer type can be preferably employed from the viewpoint of easy availability and coating film properties, and in particular, for the same reason, fluoroolefins, cyclohexyllenyl ethers, etc. , alkyl vinyl ether, hydrogen hydroxyalkyl vinyl ether as essential constituents in proportions of 40 to 60 mol, 5 to 45 mol, 5 to 45 mol, and 3 to 15 mol, preferably 45 to 55 mol, respectively.

Those containing in proportions of 10 to 30 mol, 10 to 35 mol, and 5 to 13 mol can be preferably 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 terms of production. Also, products with a high fluoroolefin content are difficult to manufacture. On the other hand, if the cyclohexyne rubinyl ether content is too low, the hardness of the coating film during binding is undesirable, and if the alkyl vinyl ether content is too low, the flexibility is undesirable. In addition, if the hydroquine alkyl 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 limit its applicability as a solution-based paint paste. Moreover, it is not preferable because it reduces the flexibility of the cured coating film and also 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 will be lost, resulting in an increase in curing time, a decrease in solvent resistance, stain resistance, etc. of the cured coating, and furthermore, it will cause poor adhesion with the undercoat, etc. This is not preferable because it causes disadvantages such as loss of quality.

In the above preferred copolymer, perhaloolefins, particularly chlorotrifluoroethylene or tetrafluoroethylene, are preferably employed as the fluoroolefins. 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. Incidentally, the fluoroolefin and alkyl vinyl ether contents are not limited to each individually, but can also be used in the form of a mixture of two or more.

Further, the copolymer may contain units based on cofluorophores other than the above-mentioned four essential constituents within a range not exceeding 30 mol. Such comonomers include ethylene and propylene.

Olefins such as inbutylene, vinyl chloride.

Haloolefins such as vinylidene chloride, unsaturated carboxylic acid esters such as methyl methacrylate.

Examples include vinyl carboxylates such as vinyl acetate and vinyl n-butyrate.

In the present invention, the fluorine-containing polymer has an intrinsic viscosity of 0.001 measured in tetrahydrofuran at 30°C in an uncured state.
05-2.0 dl/y, especially 0.07-0.8 dl
l? , it is preferable to adopt one with a certain degree. If the viscosity is too low, the mechanical strength will decrease, and if the blade is too high, when applied as a solution-type paint, there will be a tendency to lower the solution concentration due to viscosity, impairing workability. So I like both of them, <no.

In the present invention, polyvalent incyanate contains 2 in one molecule.
Polyvalent incyanate having at least 1 isocyanate group, such as ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, m-phenylene diisocyanate, p-
Phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-dolylene diisocyanate, 1,5-naphthylene diisocyanate, 4.4',
4'-triphenylmethanetriincyane), 4.4
'-Diphenylmethane-diisocyanate, 3,3'-
Excess of polyvalent isocyanates such as dimethyl-4,4'-diphenylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, isophorone diisocyanate, lysine incyanate, and the above incyanate compounds, and evaporated ethylene glycol, Pyrene gelicol, 1,5-butylene glycol, neopentyl glycol, 2,2,4-trimethyl-1,3-bentanediol, hexamethylene glycol, cyclohexane dimetatool, trimethylolpropane, hexanetriol, glycerin, penta Examples include polyvalent isocyanates having two or more functionalities obtained by an addition reaction with a low-molecular-weight polyol such as erythritol, polyvalent incyanates 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, as well as adducts thereof, are particularly useful.

The mixing ratio of the fluoropolymer and polyvalent incyanate is
(Hydroxyl group in fluorine-containing polymer)/(Incyanate group in polyvalent iso7anate) -1/ls~'10. A range of s (equivalence ratio) is preferred.

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 color vehicle containing the fluorine-containing polymer and polyvalent incyanate 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. As the organic tin polymer, for example, poly(
tributyltin acrylate), poly(tripropyltin acrylate), poly(tributyltin methacrylate),
Examples include polymers such as poly(tripropyltin methacrylate).

In this case, the amount of rosin or organotin polymer used is as follows:
0 cyanate], /80 to /20 (
weight %) degree and 99/1 to 10/,. (% 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 hydroquinde, triphenyltin acetate, triphenyltin chloride, etc.), tetramethylthiuram sulfide, zinc methyldithiocarbamate, tributyltin compounds (e.g., tributyltin fluoride, tributyltin In addition to mercury and arsenic compounds such as mercury oxide and arsenic acid, 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 1:1 of the color vehicle (solid content)
When the amount of antifouling agent mixed is less than 10 parts by weight, C.
c cannot exhibit sufficient effect as an antifouling paint, and 5
If more than 50 parts by weight is added, 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, a fine dispersing agent thereof, an IF agent during precipitation, a viscosity modifier, a leveling agent, and a gelling preventive agent. A market agent, an ultraviolet absorber, etc. can be added as appropriate.

The objects to be coated with the paint of the present invention may be oil-based anti-corrosion 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 paint of the present invention, it is usually applied to the object to be coated with a dry film thickness of 5.
It is applied and finished to a thickness of about 0 to 300 microns.

The coating film obtained in this way not only functions as an antifouling agent, but also
Because the film is formed from a fluorine-containing polymer and a polyvalent isocyanate, it provides long-term antifouling effects, and the use of a specific color vehicle provides a highly durable coating.

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

Indicated by "parts" or "parts by weight" or "wt%".

Example 1 51.2 mol % and 17.1 mol % of units based on chlorotrifluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether, and hydroxyl vinyl ether, respectively.

Contains at a ratio of 22.5 molar and 9.1 molar, and has an intrinsic viscosity (in THF, 30°C) (0η) of 0.21 d.
V? , glass transition temperature (DSC 10°C/rn temperature increase)
An antifouling paint used in the method of the present invention was prepared using a fluorine-containing quaternary copolymer having (T9) of 45°C and having the following composition.

Fluorine-containing copolymer 100 parts Bengara 40 Cuprous oxide 100 Kijirole 160 The above mixture was kneaded in a pot mill for 24 hours to obtain an antifouling paint main ingredient.

Immediately before use, a curing agent consisting of 8 parts of hexamethylene diisocyanate and 15 x 10 parts of dibutyltin dilaurate was mixed with the base material 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 IOO part fluorine-containing copolymer (same as Example 1) 100 valves Handle 6゜cuprous oxide 8゜flake glass 100 [Nippon Glass Fiber Co., Ltd. product name: c: F-1so,] Kijiroll
160 Using the above mixture, an antifouling paint (B) was prepared in the same manner as in Example 1.

Example 5 Tetrafluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether Oyohihib 1 Units based on droxytyl vinyl ether in proportions of 50.8 molar, 16.9 molar, 22.8 molar and 9.5 molar, respectively. A fluorine-containing quaternary copolymer having [η]l of 0.23/, T, of 27°C was used.

Fluorine-containing copolymer 100 parts Poly(tributyltin acrylate) 100 Bengara 100 Cuprous oxide 200 Kijiroru 240 An antifouling paint was obtained in the same manner as in Example 1 using the above mixture.

Example 4 In the same manner as in Example 1, an antifouling paint (D
) and create fC.

Poly(tributyltin acrylate) 100 petals
100 Cuprous oxide 200 Tributyltin fluoride 20 Quizylol 260 Example 5 As a fluorine-containing polymer, 1,3-di(2-hydroxyhexafluoropropyl)-ben9ph 34 molti, 1,5
- Condensation product of dihydroxy 2.2', 3.3', 4.4' hexafluoropene 2F, 33M, and epichlorohydrin 9F, 33M [OH value 780H/7. [η'
) = 0.10 (60°C in THF)], a paint having the following formulation was prepared.

Fluorine-containing polymer 100 parts
50 Tributyltin fluoride 20 Cuprous oxide
80 Kijiroru 100 The above mixture was kneaded in a bot mill for 24 hours to obtain an antifouling paint base.

Immediately before use, add 12 parts of hexamethylene diisocyanate and dibutyltin dilaure (15X10') to the main ingredient.
and a hardening agent consisting of 2 parts to obtain an antifouling paint (118). This paint was subjected to a comparative test described below.

Comparative Example 1 ゜ji, soo Polymerized linseed oil 10 Bengara 10 Cuprous oxide 30 Talc 20 Mineral spirit 20 The above mixture was kneaded in a bot mill for 24 hours to form an antifouling paint (
F) was obtained.

Comparative Example 2 ゜Scif so-based chlorinated paraffin 5 Cuprous oxide 30 Talc 20 Mineral spirits 20 Painted in the same manner as Comparative Example 1 [7, Antifouling paint (G')
I got it.

A steel plate (J-Ko 5G3141) was coated with L-Resyn Rich Brimer in the usual manner to a dry film thickness of 75 microns and dried, and then an epoxy resin paint was applied and dried to a dry film thickness of 200 microns. And so.

Each of the antifouling paints obtained in Examples 1 to 5 and Comparative Examples 1 to 2 was spray-coated onto the above-mentioned object to a dry film thickness of 100 microns, and after drying at room temperature for 10 days, it was subjected to a comparative test. provided. The results are shown in Table 1.

Table 1 Comparative test results table Test method In the immersion test, each specimen was immersed in the sea off the coast of Miho.

Evaluation of the resistance status of organisms ○: Almost no resistance △: 20
~30% adhesion resistance ×: Evaluation of the deterioration status of the full-surface adhesion resistant paint film ○: No abnormality △ D Some damage to the paint film ×: Significant paint film damage and peeling from the substrate Results of the above comparison test It is clear from the table that the coating film obtained from the underwater antifouling paint of the present invention has a longer duration of antifouling property than the coating film obtained from the conventionally known antifouling paint composition. It was rare because it was long and the paint film was not bad.

Claims (4)

[Claims] (1) An underwater antifouling paint containing a color vehicle and an antifouling agent, wherein the color vehicle contains a fluorine-containing polymer having a hydroxyl group and a polyvalent incyanate, and the vehicle contains 100 parts by weight of the color vehicle. An underwater antifouling paint characterized in that the proportion of the antifouling agent in the water is 10 to 350 parts by weight. (2) The fluorine-containing polymer is fluoroolefin 40
~60 molti, cyclohexyl vinyl ether 5-45
The underwater antifouling paint according to claim (1), which is a copolymer consisting of a molar ratio of 5 to 45 molar alkyl vinyl ether, 3 to 15 Φ of hydroxyalkyl vinyl ether, and 0 to 60 molar of other comonomers. . (3) The underwater antifouling paint according to claim (2), wherein the fluoroolefin is chlorotrifluoroethylene and/or tetrafluoroethylene. (4) Claims (1) and (2) in which the color vehicle contains a rosin or an organic tin polymer in addition to a fluorine-containing polymer having a hydroxyl group and a polyvalent incyanate The underwater antifouling paint according to any of paragraph (3).