Study of Biocide Release from Antifouling Paints — Verification of Mass Balance Calculation Method by Actual Measurement —

摘要

Mass balance calculation method, which is one of the evaluation methods to estimate the release rate of biocides into the sea from antifouling paints, is theoretical method but not the actual measuring one. This paper reports an actual measuring result in comparison with the theory of the mass balance calculation method. The procedure to achieve this purpose, consumed film thickness and consumed copper amount from test panels were measured to get the total amount of copper released, then divided by immersion periods to get the release rates of copper. The result of hydrolysis type antifouling paint showed constant copper release during the test periods. On the other hand, the result of ablative type antifouling paint showed larger copper release at the first two months then became smaller at the later periods. But when the lifetime of antifouling paints was considered, the results were close to the values of mass balance calculation method. From the results, both types of antifouling paint were considered to be applicable to mass balance calculation method.%　船底防汚剤の溶出速度の評価手法の一つであるマスバランス計算法の実測を試みた。この目的のためにわれわれが実施したrnのは，浸漬前後の防汚塗膜の膜厚と塗膜中の銅の残存量を測定することにより塗膜から溶出した防汚剤としての銅の総量を求rnめ，浸漬日数で割ることにより溶出速度を求めるという手法である。rn　加水分解型の防汚塗料においては，一年間にわたり銅の溶出はほぼ一定の値であるという結果が得られた。自己崩壊型の防rn汚塗料においては2カ月目までの銅の溶出は非常に高く，それ以降の溶出は低いという値となったが，塗膜寿命全体として考rnえた場合にはマスバランス計算法と近い値となり，いずれの塗料タイプにおいてもマスバランス計算法を適用することができrnると考えられた。