Oligomer-containing mixtures useful as fiber surface treating agents and processes for the production and use thereof

摘要

A reaction between pyromellitic dianhydride (PMDA) and less than two moles of fluoroalcohol produces an intermediate with ester, free acid and anhydride groups. Reaction with an oxirane compound such as epichlorohydrin reacts at the acid sites to produce pendant hydroxyls which react with anhydride on adjacent molecules to produce oligomers. Products with fluoroalcohol:PMDA ratios of, for example, about 1:0.6 to about 1:0.85 produce treated fibers with improved retention of oil repellancy, especially when annealed at 100 DEG -130 DEG C.