Patent attributes
The invention describes a thermally-responsive record material substantially free of aromatic isocyanate. The record material comprises a support having provided thereon a heat-sensitive composition comprising a substantially colorless dye precursor comprising a fluoran; and a developer material selected from the group consisting of 4,4′-diaminodiphenylsulfone and 3,3′-diaminodiphenylsulfone, which upon being heated react with said dye precursor to develop color, and including a binder material. Optionally, a modifier compound is included in the heat-sensitive composition. The modifier compound can be selected from the group consisting of a fatty acid amide, preferably a saturated fatty acid amide such as an alkyl amide, a bis methylene alkyl amide, or a bis ethylene alkyl amide, or any of 1,2-diphenoxy ethane, dimethyl diphenoxy ethane, and dimethyl phthalate.
