Patent ID: 9339948
Filing Date: 2016-05-17
CPC Classification: B29C,B29K,C08G,E21B,H02G

Claim Text:
1. A bend stiffener comprising (i) a flexible polymeric sleeve having a mass of at least 500 kg, an axial bore for receiving an elongated flexible member and (ii) a flange, end plate, locating cylinder-and-sleeve arrangement or guide connector and latch assembly for attaching the sleeve to a support, wherein all or a portion of the flexible polymeric sleeve is a polyurethane elastomer produced in a reaction of an isocyanate-terminated prepolymer and a curing agent at an isocyanate index of 90 to 120, wherein the isocyanate-terminated prepolymer has an isocyanate content of 7 to 15% by weight and is a reaction product of at least one aromatic polyisocyanate and at least one polyether polyol having a hydroxyl equivalent weight of 350 to 2000 and a nominal functionality of 2 to 2.3, and wherein the curing agent is one or more diol chain extenders having an equivalent weight per isocyanate-reactive group of up to 125 or a mixture containing one or more such diol chain extenders and one or more polyether polyols having a hydroxyl equivalent weight of 350 to 2000 and a nominal functionality of 2 to 2.3, and the polyurethane elastomer has a hard segment content from 40 to 60% by weight.