resins curable based on polyols having pharmacological polyoxyalkylene

摘要

To prepare a curable adhesive/sealant, an organic polyisocyanate whose isocyanate groups are bonded to aromatic or cycloaliphatic carbon atoms is reacted first with a polyalkylene ether polyol and then with an acrylic or methacrylic ester which has a hydroxyl or non-tertiary amino group in the molecule. The polyisocyanate used is preferably the reaction product of an aromatic or cycloaliphatic polyisocyanate and an aromatic or cycloaliphatic polyol or polyamine. Solvents which are coreactive in the later curing can be present. The storage-stable prepolymers have rigid and flexible segments. To adhere surfaces or seal off gaps between surfaces, the adhesive/sealant is introduced between the surfaces together with a free-radical initiator and allowed to cure. Curing can be anaerobic or by means of UV-irradiation, depending on the choice of initiator. The initiator can be added to the adhesive/sealant or applied separately to a surface. The cured adhesive/sealant is highly flexible and has excellent tensile and impact strength. Gaps more than 1 mm wide can be sealed.