Abstract: High temperature non-crystallizing cholesteric liquid crystal compositions are provided having at least about 50 weight percent of cholesteryl 3-chloropropionate, at least about 30 weight percent of a cholesteryl ester, wherein the acyl group has a substituted or unsubstituted benzene ring, and not more than 20 weight percent of other cholesteryl compounds. The compositions are found to provide billiant colors and do not crystallize when stored for long periods of time at room temperature or below.

Abstract: Thin stable, substantially uniform, liquid crystal containing films are provided by coating onto an inert, normally darkened substrate, an ink comprising an oil in water latex, a small amount of an organic solvent, usually a polar moderately water soluble organic solvent, liquid crystals and a thickening agent. The film can be used as an ornamental article of manufacture, for photographic reproduction, for temperature determination, as well as other utilitarian applications.

Abstract: A non-breakable digital thermometer and a method for its manufacture are provided. The thermometer comprises a plastic strip, either flexible or rigid, of microencapsulated temperature responsive liquid crystal material in a lateral array of numerical indicia, each index having associated with it liquid crystals having a temperature responsive range relevant to the numerical value of the index. Overlap of temperature responsive ranges is provided to insure at least one visible indicia, when the temperature being measured is within the range of interest.A substantially continuous sheet of an inert transparent base is sequentially printed with a darkly pigmented mask defining transparent indicia areas. Different liquid crystal composition slurries are coated in a continuous stripe over the appropriate indicia, with adjacent compositions allowed to mix at the edges, before rapid partial drying prevents additional mixing.

Abstract: A rapid and convenient temperature indicator is provided having a tubular heat-conducting member joined at one end to a heat sink and having the other end rounded for ease of contact with the surface whose temperature is to be measured. Conveniently, a cylindrical protective cover is provided which is slidably mounted on the heat sink by means of a slot relieved threaded member and nut. The heat-conducting tube has a darkened surface which is coated with a liquid crystal composition having a mesophase temperature range which provides a temperature response in the range of interest. One or more liquid crystal compositions may be employed providing bands along the tube. A reticule is provided, which can be calibrated to give an accurate approximation of the temperature of the surface being measured.