Prepolymer toughener for crack-resistant adhesives for windmills

摘要

A composition is described which includes A) a chain-extended prepolymer, which can be obtained from the reaction of a) a polymer containing at least one amino, thiol or hydroxyl group, b) at least one polyisocyanate and c) at least one alkoxylated bisphenol as chain extender, and optionally d) an epoxide compound containing a primary or secondary hydroxy group, said compound containing a primary or secondary hydroxyl group, or at least one epoxy resin A which contains this epoxide compound, and optionally B) an epoxy resin B. The composition is suitable as a toughener or as an A component of a 2k epoxy resin adhesive which contains this toughener. The adhesive is suitable particularly for bonding in windmills.

主权项

1. A composition comprising a chain-extended prepolymer that is obtained by the reaction of
a) at least one polymer of formula (I) wherein X1═O, S or NH; Y1 represents an n-valent radical of a reactive polymer after removal of terminal amino, thiol or hydroxyl groups; and n=2, 3 or 4; b) at least one polyisocyanate of the formula (II) wherein Y2 represents a divalent radical of aliphatic, cycloaliphatic, aromatic or araliphatic diisocyanates after removal of the isocyanate groups, or a trivalent radical of trimers or biurets of aliphatic, cycloaliphatic, aromatic or araliphatic diisocyanates after removal of the isocyanate groups; and m=1 or 2; and c) at least one alkoxylated bisphenol as chain extender, wherein the at least one alkoxylated bisphenol has 3 to 15 mol of alkyleneoxy units per mol of bisphenol, and d) an epoxy compound containing a primary or secondary hydroxyl group of formula (III) wherein Y3 represents an aliphatic, cycloaliphatic, aromatic or araliphatic epoxy containing a primary or secondary hydroxyl group after removal of the epoxy groups and the primary or secondary hydroxyl group; and q=1, 2 or 3; or at least one epoxy resin A containing an epoxy compound of formula (III).