Abstract: A new reversible heat sensitive recording composition for erasable recording is disclosed which is used as a recording or marking material that is capable of erasure at a specific temperature so that coloring or decoloring can be controlled to occur at desired temperature ranges. This range or the hysteresis value of the composition is determined by the .DELTA.T value of the contained ester compound. In addition, the composition can provide a wide variety of hues and can readily be prepared. The marking or recording drawn in this composition can be maintained at room temperature or less.

Abstract: A thermochromic composition comprising (1) an electron-donating chromogenic material, (2) a 1,2,3-triazole compound, (3) a weakly basic, sparingly soluble azomethine or carboxylic acid primary amine salt, and (4) an alcohol, amide or ester serving as a solvent.

Abstract: A pressure-sensitive recording material of the type which is prepared by using an electron donating dye-precursor that produces a color when the dye-precursor is brought into contact with an electron accepting color developer. The pressure-sensitive recording material is characterized in that the solvent for said dye-precursor comprises an alkylated fraction which is prepared by alkylating a by-product fraction with at least one alkyl group having 1 to 5 carbon atoms, the by-product fraction containing the components within the boiling range of 255.degree. to 300.degree. C. on the atmospheric pressure basis and being obtained in the process for producing ethylbenzene or ethyltoluene from ethylene and benzene or toluene. The pressure-sensitive recording material of the invention has scarcely offensive odor and can develop a dense color with a higher color developing rate.

Abstract: The invention relates to a process for encapsulating solutions of reactants of color reaction systems by means of conventional encapsulation processes, the reactant initially being dissolved in a solvent with a good dissolving power and immediately prior to emulsification or encapsulation, a non-solvent, which only dissolves the reactant to an insignificant extent, is admixed with the fresh solution obtained in a quantity which adjusts a supersaturated system, the capsulates obtainable as a result thereof, as well as their use with an encapsulated solution of a basic color former, which supplies a color by the reaction with acid reactants, in non-carbon paper.

Abstract: A heat-sensitive recording material is described, comprising a support comprising thereon a layer containing microcapsules containing a leuco dye and an organic solvent in a core thereof and a color developer outside of said microcapsules capable of reacting with said leuco dye to develop a color, wherein a glass transition point of said microcapsule wall is from about 60.degree. C. to 200.degree. C.

Abstract: Disclosed is a pressure-sensitive record unit which comprises a top sheet having coated on the underside thereof solid color former material and a bottom sheet having coated on the upper side thereof a coating comprising solid color developer material and microcapsules containing a liquid solvent for the color former. Such a record unit makes possible the unexpectedly efficient utilization of the color former material. It furthermore permits the printing application of some of the components, resulting in even more efficient utilization of color former material and elimination of undesirable side effects of printed record units taught in the prior art.