High-functionality polyisocyanates containing urethane groups

摘要

The present invention relates to new, urethane-group-containing polyisocyanates based on aliphatic and/or cycloaliphatic diisocyanates, and to their use.

主权项

1. A high-functionality polyisocyanate, comprising urethane groups and obtained by:
reacting (a) at least one alkoxylated polyfunctional alcohol (A) obtained by alkoxylating trimethylolpropane with one or more alkyene-oxide units selected from the group consisting of ethylene oxide and propylene oxide, and having a OH-functionality which is on average more than 2; (b) at least one polyisocyanate (B) having an NCO-functionality of more than 2, which comprises at least one selected from the group consisting of an isocyanurate group, a biuret group, a uretdione group, and an allophanate group and is constructed from at least one selected from the group consisting of an aliphatic isocyanate and a cycloaliphatic isocyanate, under reaction conditions under which urethane groups are formed between (A) and (B), with the proviso that a molar ratio of NCO groups to OH groups between (B) and (A) is at least 3:1, and wherein the polyisocyanate (B) comprises a uretdione group.