摘要:
A color developer for pressure-sensitive copying paper is prepared by mixing a polyvalent metal salt of a para-substituted difunctional phenol-aldehyde condensate and a tri- or higher-functional phenol-aldehyde condensate and/or a polyvalent metal modified tri- or higher-functional phenol-aldehyde condensate.
摘要:
A polyurethane composition comprising a polyurethane and at least one dye selected from the group consisting of metal complex dyes, vat dyes, sulfur dyes and acid dyes. The polyurethane is synthesized by the reaction of a polymeric diol containing a polyoxyethylene chain as a minor proportion, an alicyclic diisocyanate, an alicyclic diamine and hydrazine in particular proportions. This polyurethane composition is little susceptible to deterioration by light and is suitable for use as a component of artificial leather or as a coating material for fabrics.
摘要:
Improved aqueous color developing compositions for copying papers are prepared by emulsifying phenolic resins having relatively low molecular weights. The aqueous emulsions are prepared by condensing a phenol and an aldehyde in the presence of an acid catalyst, and without the customary steps of high temperature concentration or dry pulverization of the solid resin the precondensate is directly emulsified with starch or other emulsifiers while in a liquid state. Uniformity of resin particle size is achieved by accelerated agitation of the precondensate. The process provides stable emulsions with fine resin particles having a diameter of under about 7 microns, which excel in color developing properties, fastness to light and have extended shelf life.