Лако-красочные материалы — производство

Triphenylmethanes are used mainly for nontextile purposes. Almost all of the leuco bases of triphenylmethane dyes are used in the color-forming applications, e. g., in novel types of colorless copying papers. Other applica­tions include pressure-sensitive heat-sensitive materials, high-speed photo duplicating copying papers, light-sensitive papers, ultrasonic recording pa­pers, electrothermic heat-sensitive recording papers, inks, crayons, type­written ribbons, and photoimaging systems. Many of these applications generally involve microencapsulation of the leuco dye in one layer, an electron acceptor or acid in another layer. When they are brought into
contact either by pressure, heat, or light, electron-transfer reactions occur and a color image is generated. Images are generated by a variety of techniques. For example, a leuco dye and an acid solution can be dispersed and printed on a rayon unwoven cloth. When a pattern is used to partially cover the sheet and then a solvent such as ethanol is sprayed on the surface, a copy of the pattern on a colored background is generated.105