Polyurethane polyanhydride oligomers and method of preparation
AssigneePPG Industries, Inc.
InventorsJonathan T. Martz, Karl F. Schimmel, Padmanabhan Sundararaman, David N. Walters
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Abstract
A polyurethane polyanhydride oligomer is disclosed as well as a process for its preparation. The process involves the following steps: (a) reacting a hydroxyl functional 2,4-dienoate ester with a polyisocyanate under conditions sufficient to react essentially all of the isocyanate groups to form a polyurethane polyene; and (b) reacting by Diels Alder addition the unsaturated double bonds of the polyurethane polyene with an unsaturated polycarboxylic acid anhydride containing material. Also disclosed is a curable composition containing hydroxyl functional material and the aforedescribed polyurethane polyanhydride oligomer.
Claims15
A polyurethane polyanhydride oligomer characterized in that it comprises at least one moiety represented by the following structure:
- ##STR7## wherein:
- X is:
- ##STR8## wherein n is 0, 1, 2, 3, or a fused ring system;
- R.sup.1 is hydrogen or an aliphatic radical;
- A and B are both CH-- in which case R.sub.2 and R.sub.3 are independently hydrogen or an aliphatic radical;
- or
- A and B are connected to form --C.dbd.C--
- R.sup.4 is the residue of a mono or polyisocyanate;
- R.sup.5 is an aliphatic group, aromatic group, alicyclic group or ##STR9## R.sup.6 is an aliphatic, aromatic or alicyclic group.
A process for preparing a polyurethane polyanhydride oligomer comprising the steps:
- a) reacting a hydroxyl functional 2,4-dienoate ester with a polyisocyanate under conditions sufficient to react essentially all of the isocyanate groups to form a polyurethane polyene;
- and
- b) reacting by Diels Alder addition the unsaturated bonds of the polyurethane polyene with an unsaturated polycarboxylic acid anhydride containing material.
Dependencies are inferred from the claim text.