Polyurethane or polyurethane-urea aqueous dispersion, preparation method therefor, and use thereof

A polyurethane or polyurethane-urea aqueous dispersion, wherein the polyurethane or polyurethane-urea aqueous dispersion is a reaction product obtained by reacting a composition comprising the following components:

• a) at least one silane component having a general formula of
• wherein group R contains at least two NCO-reactive groups, wherein at least two of groups R1, R2 and R3 are methoxyls and/or ethoxyls, and the remaining groups R1, R2 and/or R3 is an alkyl;
• b) at least one polyol component having a functionality of 2-4, wherein the component b) comprises a mixture of a crystalline polyol having a number average molecular weight of 400-15,000 and at least one non-crystalline polyol having a number average molecular weight of 400-15,000;
• c) at least one polyisocyanate component;
• d) at least one hydrophilic compound component, the hydrophilic group of the hydrophilic compound comprises one or two of an ionic group and a potentially ionic group, the hydrophilic compound contains 2-3 NCO-reactive groups;
• e) at least one NCO-reactive, monofunctional nonionic hydrophilic compound component;
• and
• f) optionally, a compound containing 1-3 aminos and/or hydroxys in the molecule;
• and
• g) optionally, other isocyanate-reactive compounds.