JPH028623B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to stable underwater antifouling paints. More specifically, the present invention relates to an underwater antifouling paint containing a tributyltin polymer compound, cuprous oxide, and a stabilizer that is prevented from thickening or gelling. Conventionally, paints containing cuprous oxide as an effective antifouling ingredient have been used to prevent marine organisms such as barnacles and sea lettuce from adhering to ships and various underwater structures. Vinyl resin-based antifouling paints (extraction type) and oil-based antifouling paints (dissolving type) have been used as this paint, but the initial elution amount of copper ions is large and the antifouling power is not sustainable. It has various problems in terms of alkali resistance, drying properties, coating strength, etc., and is not a satisfactory antifouling paint. Triorganotin compounds such as triphenyltin salts and tributyltin salts have been used as antifouling agents to compensate for this drawback. Triorganotin polymer compounds, which are produced by reacting polymer compounds such as acrylic resins and alkyd resins with triorganotin oxides, hydroxides, or halides, have been attracting attention. Antifouling paints containing triorganotin polymer compounds as the antifouling component not only maintain antifouling performance over a long period of time by minimizing the elution amount of active ingredients, but also improve the stability during painting and improve fuel efficiency. This is an innovative paint that saves money. The excellent properties of this triorganotin polymer compound are thought to be that the elution of the triorganotin component, which is an active ingredient, is controlled as a result of gradual hydrolysis in seawater. Triorganotin polymer compounds can be used alone, but in order to stabilize the antifouling effect, they are usually used together with inorganic copper. However, when an antifouling paint is prepared using a combination of cuprous oxide and a triorganotin polymer compound, it has been observed that the paint often undergoes changes over time during storage, resulting in thickening or, in severe cases, gelling. To solve this problem, there are various methods such as a two-component method in which cuprous oxide and a high-molecular organic tin compound are mixed together during painting, and a method in which the expensive and highly toxic Rodan copper is used as a substitute for cuprous oxide. Attempts have been made, but none have yet been satisfactory enough to be commercialized. The inventors of the present invention have conducted extensive research into methods for stably storing antifouling paints containing cuprous oxide and tributyltin polymer compounds, which have traditionally been used as active ingredients at low cost and are highly safe, for long periods of time. The present invention was completed based on the discovery that the above antifouling paint could be stabilized by adding a small amount of trialkyltin phosphate as an agent. As the tributyltin polymer compound used as an active ingredient in the present invention, triorganotin salt monomers of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid are synthesized, and monomers of these monomers are synthesized. alkyl esters of vinyl chloride, vinyl acetate, vinylidene chloride, acrylic acid or methacrylic acid;
Examples include copolymers with copolymerizable unsaturated compounds such as styrene and vinyltoluene, and polymer compounds obtained by reacting the carboxyl groups of high acid value alkyd resins or acrylic resins with tributyltin compounds. It will be done. In addition to the tributyltin polymer compound mentioned above, we also use natural resins, chlorinated rubber, polyethylene chloride, and vinyl copolymers to strengthen the coating film, adjust its viscosity, and improve the dispersibility of cuprous oxide, the other active ingredient. Resins such as resins, styrene-butadiene copolymer resins, acrylic resins, and epoxy resins may be used in combination. In addition, extender pigments, coloring pigments, plasticizers, etc. that are generally added to paints can also be used.
Even if these components react with the stabilizer of the present invention,
Any substance can be used as long as it does not reduce its performance, and the proportion of each component in the paint is as follows:
It can be determined by considering conditions such as pigment volume concentration and antifouling performance. The amount of the stabilizer added in the present invention is not particularly specified, but it is 0.1% to 3%, preferably 0.5% based on the entire coating composition, based on the formulation, antifouling performance, economic efficiency, etc.
% to 1% is appropriate. Further, the stabilizer of the present invention exhibits sufficient effect when used alone with trialkyltin phosphate, but there is no problem when used in combination with trialkyltin oxide. Depending on the composition of the paint, more effects than one can be expected. The addition of trialkyl tin oxide is not particularly limited, but it is economical to add 1% or less. Hereinafter, the present invention will be explained in detail by giving examples. Production example 1 Synthesis of tributyltin polymer compound 350g of tributyltin methacrylate and 150g of methyl methacrylate were dissolved in 500g of xylene, and 2.5g of benzoyl peroxide was added as a polymerization initiation catalyst.
is added and polymerized for 10 hours at 90-110°C to obtain a 50% xylene solution of a pale yellow viscous copolymer. The average molecular weight of this copolymer is 17,000 according to gel permeation chromatography. Production example 2 Synthesis of tributyltin polymer compound Tributyltin methacrylate 325g, methyl methacrylate 125g and butyl acrylate 50g
Dissolve g in 500 g of xylene, add 2.5 g of benzoyl peroxide as a polymerization initiation catalyst, and heat at 80 to 100℃.
When polymerized for hours, 50% of pale yellow viscous copolymer
A xylene solution is obtained. The average molecular weight of this copolymer is 21,000 according to gel permeation chromatography. Example 1 Preparation of paint A 50% xylene solution of the tributyltin polymer compound synthesized in Production Examples 1 and 2 was blended with other components in the amounts shown below, and mixed by ball mill dispersion to prepare a standard test paint. () Composition of paint A Compound solution of Production Example 1 50% by weight Cuprous oxide 35 Petal handle 5 Talc 5 Xylene 5 () Composition of Paint B Compound solution of Production Example 2 50% by weight Cuprous oxide 35 Petal handle 5 Talc 5 Xylene 5 Example 2 Storage Stability Test The test results for the standard test paints A and B of Example 1 and the paint with 1% stabilizer added are shown in Tables 1 and 2. In addition, in order to perform an accelerated test, the paint
The paint was placed in a 500ml glass pin, sealed, and stored in a constant temperature room at 50°C, and the viscosity of the paint was examined for one month. The viscosity was measured using a B-type viscometer (using rotor No. 4), and the viscosity at the time of preparation was used as a reference, and the viscosity increase is shown below as a magnification. The viscosity magnification was symbolized as follows. Less than 2 times……◎ More than 2 times to less than 4 times……〇 More than 4 times……×

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Claims (1)

[Claims] 1. A stable underwater antifouling paint characterized by containing a tributyltin polymer compound and cuprous oxide as active ingredients and trialkyltin phosphate as a stabilizer.