Materials suitable as crosslinkable binder components

摘要

Polymeric materials (I) having an average molecular weight from 4000 to 30,000 are obtainable by reacting 1) A polyurethane (II) comprising a) 1 mol of a diol (III) having an average molecule weight of from 400 to 4000, b) from 0.3 to 9 mol of an aliphatic or cycloaliphatic diol (IV) of 2 to 18 carbon atoms, c) from 0.3 to 9 mol of an aromatic diol (V) of 8 to 30 carbon atoms, d) from 0.01 to 1 mol of a trihydric alcohol (VI) of 3 to 18 carbon atoms, e) from 0.001 to 1 mol of a polyhydric alcohol (VII) of 3 to 14 carbon atoms which contains a tertiary amino group and f) an amount of a diisocyanate (VIII) of 6 to 30 carbon atoms such that the molar ratio of the isocyanate groups to the total number of hydroxyl groups in (III) to (VII) is from 1.05:1 to 1.4:1 with 2) a compound (IX) which contains one or more hydroxyl groups and one or more amino groups reactive toward isocyanate groups, the amount of (IX) being such that the number of reactive amino groups corresponds to the number of isocyanate groups in the polyurethane (II). The materials may be used as crosslinkable binder components for pigment-containing coatings, in particular for the production of magnetic recording materials.