Diol-terminated polycarbonates and their use in reactive adhesive and/or sealing formulations

Claim 1

Diol-terminated polycarbonates having the general formula (I): HO - (R₁-O-CO-O) x - (R₂-O-CO-O) y -R₃OH wherein: the succession of radicals -R₁-O-CO-O- and -R₂-O-CO-O- inside the copolymer is of a purely random type, R₁ is a linear alkylenic radical deriving from a HO-R₁-OH diol by the loss of the two hydroxyls and containing from 8 to 14 carbon atoms, or represents a mixture of the same radicals. R₂, different from R₁, is a bivalent radical selected from: a) alkylenic radicals linear or branched or cycloalkylenic radicals, containing from 2 to 14 carbon atoms; b) Divalent radicals deriving from polyetherdiglycol terminated by the loss of the two hydroxyls. c) the Divalent radical: d) the bivalent radical -(CH₂) m --COO-(CH₂-) n - deriving from the condensation of a lactone with a linear aliphatic glycol, by the loss of the two hydroxyls, where m is a number between 3 and 5 whereas n is a number from 4 to 14, or e) a mixture of 2 or more bivalent radicals among those listed in paragraphs a), b), c), and d), R₃ is a Divalent radical equal to R₁ or R₂, and x and y have such values that: a) the fraction of the structural units corresponding to: ―(R₁OCO-O) x ― represents from 50 to 95% by weight of the whole copolymer; b) the number molecular weight (MW) of the polycarbonate diol having general formula (I) must be between 1500 and 15,000.