Moisture-curing hotmelt adhesives
AssigneeHenkel Kommanditgesellschaft auf Aktien
InventorOlaf Kube
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Abstract
Disclosed are moisture-curing hotmelt adhesives containing polyurethane prepolymers with an isocyanate group content of 0.16-0.84 moles of isocyanate groups per kilogram of prepolymer, the prepolymers being obtained by reacting crystalline polyester polyols having a mean molecular weight of 2,000-10,000, optionally mixed with liquid and/or amorphous polyester and/or polyether polyols having an isocyanate functionality greater than one, the adhesives also containing diisocyanates trimerized to give isocyanurates. Adhesives of this kind have improved processing characteristics and are easier to use.
Claims20
A moisture-curing hotmelt adhesive containing:
- a) polyurethane prepolymers with a content of NCO groups of 0.16 to 0.84 moles of NCO groups per kg of prepolymer formed by reaction of (i) at least partly crystalline polyester polyols which are solid at room temperature and have a degree of crystallization of at least 30% and a number average molecular weight in the range from 2000 to 10,000, optionally in admixture with liquid polyester polyols which are liquid at 20° C. and have a glass temperature below 0° C., with amorphous polyester polyols which are solid at ambient temperature and have a glass temperature above 0° C., with polyether polyols having a number average molecular weight of 500 to 10,000, or with mixtures of any two or more of said liquid polyester polyols, amorphous polyester polyols, and polyether polyols with (ii) isocyanates;
- having a functionality of more than 1 which are not isocyanurates and
- b) isocyanurates that are trimers of diisocyanates.
Dependencies are inferred from the claim text.