An isothiazolone compound, 4, 5-dichloro-2-n-octyl-4-isothiazolin-3-one (RH-287) which is active ingredient in Sea-NineTM 211, is one of the alternative tin-free antifoulants which show high activity against a wide range of bacteria, algae and fouling organisms. A simple and sensitive method for determination of RH-287 at low parts per billion (ppb) level in seawater has been developed by gas chromatography. RH-287 in seawater that leached from an antifouling paint film was extracted into hexane, and determined by gas chromatography with an electron capture detector (GC-ECD). The recoveries of RH-287 (12.6, μg/l) spiked into seawater were 92.9 to 100.6%. The limit of determination of RH-287 using 100ml of seawater was 0.3μug/l for this analytical method. The GC method was applied onto measurement of the leaching rates (μg/cm2/day) of RH-287 from antifouling paints containing Sea-NineTM 211 and TEP-RH 287 complex.
Polymeric surfactants, poly (1, 1, 2, 2-tetrahydro heptadecafluorodecyl acrylate) and poly (1, 1, 2, 2-tetrahydro heptadecafluorodecyl methacrylate) were synthesized by radical polymerization in supercritical CO2. They were used as surfactants for the dispersion polymerization of methyl methacrylate, methyl acrylate, acrylic acid, methacrylic acid, styrene, 2-hydroxyethyl methacrylate, glycidyl methacrylate, n-butyl methacrylate, n-butyl acrylate, 2-ethyl hexyl methacrylate and lauryl methacrylate. In the case of polymers that have high glass transition temperature, spherical micropowder was successfully obtained. On the other hand, in the case of polymers that have low glass transition temperature, conversion was generally low and the melt polymers were formed. The existence of excess amount of fluorine on the particle surface was confirmed by ESCA analysis. In the course of the study, a new, branched network structure was found.
Hitherto, water-soluble dyes have been used for recording liquids for ink jet printers. In recent years, however, pigments, such as carbon black, have been used as colorants for upgrade of image quality and recording speed. In fact, surface-modified carbon black by oxidation or organic reactions is used for water-based inks by dispersion without dispersants. This type of surface-modified carbon black is generally called “self-dispersed carbon black (CB)”. Dispersibility of the self-dispersed CB will be improved by neutralization of acidic functional groups on its surface with basic compounds. Therefore, the use of the basic compounds is indispensable. In this study, fundamental properties of self-dispersed CB neutralized by several kinds of alkali metal hydroxides were studied. Many properties of the neutralized self-dispersed CB were measured after it was kept at 343K for up to 4 weeks. When electronegativity of the alkali metal cations or particle size of carbon black in the self-dispersed CB solutions was smaller, the difference of electric conductivity between the initial state and after 4 weeks was larger. Also its viscosity increased greater after 4 weeks. Also when the electronegativity was smaller in self-dispersed CB with smaller particle, its blackness as well as its settling ratio was higher.