Hydrophilic polyisocyanates

摘要

The invention relates to water-soluble or water-dispersible, hydrophilic polyisocyanates and polyisocyanate mixtures, to a process for preparing them, and to their use as a starting component in the production of polyurethane polymers, more particularly as crosslinkers for water-soluble or water-dispersible film-forming binders, adhesives binders, or sealant binders or binder components with or without groups which are reactive towards isocyanate groups.

主权项

1. A hydrophilic, water-soluble or water-dispersible polyisocyanate, comprising 4% to 27% by weight of isocyanate groups, said groups being aliphatically, cycloaliphatically, araliphatically and/or aromatically attached isocyanate groups,
wherein the polyisocyanate has an average functionality of 2.0 to 5.0 and is synthesized from: A) at least one diisocyanate or polyisocyanate component having an average functionality of 2.0 to 5.0 and having 8% to 27% by weight of aliphatically, cycloaliphatically, araliphatically and/or aromatically attached isocyanate groups (calculated as NCO; molecular weight=42); and B) 0.3% to 25% by weight, based on the total weight of components A) and B), of at least one emulsifier (B) of the formula (1):
X-[y]-Z  (1), wherein: X represents one or more hydrophilic structural units formed from a substance class X′, where X′ comprises at least one group b) selected from the group consisting of a hydroxyalkylcarboxylic acid, a hydroxyalkylsulphonic acid, a hydroxypolyethersulphonic acid, and a hydroxyalkyl-N,N-dialkylamine of the formula HO—R2NR3R4, wherein R2 R3 and R4 independently represent alkyl groups having 1-18 carbon atoms, said group b) optionally branched or comprising a ring; y represents an optional spacer; Z represents one or more hydrophobic structural units; the emulsifier (B) comprises a functional group which is reactive towards isocyanate groups; and A) and B) are reacted with one another such that an equivalents ratio of NCO groups to functional groups which are reactive towards NCO groups of 2:1 to 400:1.