Novel dichroic dyes having trans-alkylcyclohexylphenyl moiety that were components of liquid crystals were synthesized. Their order parameter (S), colorability, and solubility were discussed in detail. The S values of dichroic dyes in liquid crystals (ZLI-1132 and ZLI-1840) were 0. 62-0. 77. The S values were affected by the nature of the host liquid crystals. The S values were slightly higher in ZLI-1840 than in ZLI-1132.
Highly reflective, uniform and stable thin composite films of Ni-organic pigment were prepared in two steps. First, a thin film of organic pigment was prepared on a nickel substrate by electroless plating of this pigment by reduction of a nonionic azo-surfactant (AZPEG, 1). Electrodeposition of nickel on the substrate covered with this pigment film was then carried out by controlled potential electrolysis in a chloride bath at 25°C. The concentration of nickel ion and the pH of the bath were found to have great influence on the preparation of uniform composite films. The volumetric content of pigments in the composite was found to be very high (84. 8 vol%). The adhesion of these composite films to the substrate was found to be much stronger than that of the pigment film alone. Using polystyrene, the adhesion of the films was found to be further improved by thermal treatment.
Water-borne two-pack isocyanate-free paints cured at ambient temperature by a cross-linking reaction between carbonyl and hydrazide groups were applied to plastic coatings. The coatings on PSt, PMMA, and ABS panels that has been cleaned by organic-solvent washing indicated good adhesion and water resistance. On the other hand, they were not improved for the coatings on PP panel by this method. The same paint resins without cross-linking agent were also available as primers for the former three plastic panels. Chlorinated polyolefin should be coated for PP panel as a primer resin. The primer thickness required to maintain enough coating properties was at least 5, um for the former three plastic panels, while 1, um was enough for PP panel. As the result, coating properties on PP panel were improved using very simple way : dipping in dilute solution of chlorinated polyolefin resin and drying at ambient temperature. This method is only applicable for water-borne paints which do not damage the primer film.