Urea and biuret prepolymers of MDI
AssigneeMiles Inc.
InventorsWilliam E. Slack, Rick L. Adkins
Life of this patent
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Abstract
Disclosed herein is a liquid isocyanate prepolymer having an isocyanate group content of from 10 to 30% by weight, prepared by reacting: i) a polyfunctional secondary amine group containing material of the general formula: ##STR1## wherein R represents alkyl, alkenyl, cycloalkyl, aralkyl or aryl radical: A represents an organic radical having a molecular weight between 28 and 6000 and having a functionality of m and m represents an integer from 2 to 6; with ii) an isocyanate mixture comprising: a) from 50 to 100% by weight of diphenylmethane diisocyanate of which from 2 to 50% by weight consist of 2,2'- and 2,4'-isomers; and b) the balance being polyphenylpolymethylene polyisocyanates.
Claims3
A liquid isocyanate prepolymer having an isocyanate group content of from 10 to 30% by weight, prepared by reacting:
- i) a polyfunctional secondary amine group containing material of the general formula:
- ##STR4## wherein R represents alkyl alkenyl cycloalkyl aralkyl or aryl radical;
- A represents an organic radical having a molecular weight between 28 and 6000 and having a functionality of m and
- m represents an integer from 2 to 6;
- with
- ii) an isocyanate mixture comprising:
- a) from 50 to 100% by weight of diphenylmethane diisocyanate of which from 2 to 50% by weight consist of 2,2'- and 2,4'-isomers;
- and
- b) the balance being polyphenylpolymethylene polyisocyanates.
Dependencies are inferred from the claim text.