Patent ID: 6756468
Filing Date: 2004-06-29
Classification: C08G,C09D

Abstract:
Compositions for coating having a dry content higher than 80% by weight, comprising polyisocyanates and (per)fluoropolyethers completely crosslinkable also in a range of temperatures between 5Â° C. and 20Â° C., said compositions comprising the following components:Component 1): mixture comprising: 1.a) Partially fluorinated prepolymers, having free NCO groups, obtained by reaction of (per) fluoropolyethers (PFPEs) diols having number average molecular weight Mn in the range 800-1,500, with a cyclic trimer of the isophoronediisocyanate (IPDI), in said reaction the ratio in equivalents between the OH/NCO groups being in the range 0.20-0.25, 1.b) biuret of hexamethylendilsocyanate (HDI) having an absolute viscosity at 20Â° C. lower than 5,000 mPa.s, in component 1) the ratio referred to the dry product between the compound 1.b) and the compound 1.a) being in the range 10-90 parts by weight of compound 1.b)/100 parts of compound 1.a); Component 2): (per) fluoropolyether (PFPE) diol having Mn in the range 350-700, the amount of PFPE diol component 2) being such that the ratio in equivalents between the OH and NCO groups in the composition is in the range 0.9-1.1; Component 3): inert organic solvent being the remaining part to 100% by weight of the composition.