| 摘要 |
<p>A magnetic recording carrier which has improved mechanical properties as a result of a highly active cross-linking reaction of the polymeric binder is produced by carrying out the cross-linking reaction by way of oligo- and/or polyurethanes and/or polyureas containing oxadiazine trione rings in the presence of hydroxyl groups and/or aliphatic amino groups. The oligo- and polyurethanes containing the oxadiazine trione ring are reaction products of A polyisocyanates with a functionality of from 1.95 to 2.05, preferably from 1.99 to 2.01 and B compounds containing predominantly two zerewitinoff active hydrogen atoms, selected from hydroxyl and/or amino compounds in the molecular weight range of from 18 to 6000. under the condition that the ratio of isocyanate groups present in A to zerewitinoff active hydrogens present in B lies in the range of from 0.75:1 to 1.1:1 and from 5 to 100 mol % of the polyisocyanate mentioned under A are polyisocyanates containing an oxadiazine trione ring, and catalytic quantities of tertiary amines and/or aliphatic polyamines are optionally added for hardening the magnetizable layer.</p> |
