Patent ID: 11866619
Assignee: LUMINA ADHESIVES AB
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  A | IPC A  C

Claim 24:
25. A switchable adhesive composition comprising, in proportions by weight based on the weight of the composition:
90% to 99.95% of an adhesive component; and
0.05% to 10% of photoinitiator;, wherein the adhesive component is a polymer comprising:
(i) a polyether or polyester polyol that is capable of undergoing cross-linking with isocyanate by a mechanism other than free radical polymerisation, the polyether or polyester polyol having an average of more than one functional group containing an active hydrogen atom, a proportion of the functional groups containing an active hydrogen atom being reacted with and bonded to a curable moiety that is curable by free radical polymerisation, such that the adhesive composition comprises up to 98% by weight of such curable moieties, and having a weight average molecular weight in the range 100 to 1,000,000 dalton, and
(ii) at least one isocyanate having an average of more than one isocyanate functions to cross-link the material and having a weight average molecular weight in the range 100 to 1,000,000 dalton;
characterized in that the switchable adhesive composition is adapted to irreversibly switch from a tacky state to a low-tack state responsive to irradiation by visible light or UV light.