Abstract: The present invention relates to a pearl luster pigment on the basis of a platelet-shaped substrate coated with metal oxides and a top layer which is located on the metal oxide layer and can possess a multilayer structure, comprising a first layer, containing a hydroxide or oxide hydrate of the elements aluminum or silicon, a second layer, containing at least one hydroxide or oxide hydrate of the elements aluminum, silicon, cerium or zirconium, with the exception of the hydroxide or oxide hydrate which forms the first layer, and a third layer, containing at least one organic hydrophobic coupling agent. The present invention also relates to a preparation process and the use of pigments in paints, inks, plastics, coatings and cosmetics.

Abstract: The invention relates to a process for eliminating halogenated compounds that are contained in a gas or a liquid that comprises hydrogen and unsaturated hydrocarbons, in which the gas or the liquid is successively brought into contact with: at least one catalyst for hydrogenation, then at least one adsorbent of halogenated compounds. This gas or this liquid can be obtained from. a regenerative-type catalytic reforming.

Abstract: The invention relates to copolymers made from mono-reactive liquid and/or di-reactive liquid crystals which can be photopolymerized to form copolymers and to novel reactive liquid crystal compound having a nematic phase. Preferentially the reactive liquid crystal is polymerized while in the liquid crystal phase to produce an oriented birefringent polymer film. To do this, the reactive liquid crystal, in its nematic or smectic phase is aligned (by well known techniques such as rubbed polyimide, etc.) and the thin film containing a small amount of photoinitiator, is subjected to ultraviolet light whereupon it polymerizes into a thin, aligned polymer film.

Abstract: Needle valves which are seated in valve seats defined by circular edges have DELRIN.RTM. tips for the purpose of minimizing unseating torque which would otherwise be excessive due to the thermal expansion and contraction characteristics of the valve seats and the needle valves. In salt spreaders with aluminum valve seats and steel needle valves, the needle valves become stuck in the valve seats if the needle valves are seated after operation in frigid weather and the salt spreaders are subsequently garaged to raise the temperature of the valve seat and needle valves. By utilizing the DELRIN.RTM. tips, the needle valves do not become stuck.