Polyurethane dispersions esp. for coating textiles and leather - based on di:isocyanato:di:cyclo:hexyl:methane

摘要

Polyurethanes (I) are derived from polyisocyanates (II), NCO-reactive cpds. with OH gp(s). (III) and opt. cpds. with prim. or sec. amino gp(s). (IV). At least 40 mole% of (II) consists of di-isocyanato-dicyclohexyl-methane (DCHMDI), at least 30 wt% of which consists of the trans/trans isomer. The required DCHMDI mixt. is readily obtd. by sepn. of the solid trans/trans isomer from the cis/cis and cis/trans isomers at below deg. C followed by back-mixing as required. IPDI is preferred as a further isocyanate component. Pref. (III) are polyether-polyols or polyester-polyester-polyols, and (IV) are mixts. of IPDA and diethylenetriamine. USE/ADVANTAGE - Used as coating materials, esp. for textiles and leather (claimed). Polyurethanes (PU) with the above compsn. enable the prodn. of soft coatings with a low degree of stickiness, on leather, textiles etc. (contrast prior-art PU based on normal DCHMDI mixts., e.g. Desmodur W (RTM) with 20-25 wt% trans/trans isomer).