Isocyanate-reactive component for preparing a polyurethane-polyurea polymer
An isocyanate-reactive component is disclosed that reacts with a liquid polyisocyanate or polyisocyanate prepolymer in the preparation of a polyurethane-polyurea polymer. In one embodiment, a polyisocyanate component is reacted with an isocyanate-reactive component. The polyisocyanate component has an NCO group content of about 3% to about 50% and an average functionality of about 2 to about 3. The isocyanate-reactive component includes from about 20% to about 90% by weight, based on 100% by weight of the isocyanate-reactive component, of at least one organic compound having a mercaptan functional moiety.
1. A process for preparing a polymer that coats a substrate, comprising:
providing a polyisocyanate component including aromatic isocyanates, the polyisocyanate component having an NCO group content of about 3% to about 50% and an average functionality of about 2 to about 3;
providing an isocyanate-reactive component, the isocyanate-reactive component including amines selected from the group consisting of aromatic primary and secondary amines and aliphatic primary and secondary amines, and from about 20% to about 90% by weight, based on 100% by weight of the isocyanate-reactive component, of at least one polysulfide compound having hydrosulfide (—SH) terminations, the isocyanate-reactive component having an NCO group content of 0%;
reacting the polyisocyanate component and the isocyanate-reactive component using a high-pressure impingement mixing technique at a temperature in a range of about 145° F. to about 190° F.; and
coating the substrate with the reaction product.
2. The process as recited in claim 1 , wherein the polyisocyanate component and the isocyanate-reactive component are reacted in approximately a 1:1 ratio.
3. The process as recited in claim 1 , wherein the polyisocyanate component comprises a reaction product of diphenylmethane diisocyanate and caprolactone.
4. The process as recited in claim 1 , wherein the isocyanate-reactive component comprises a reaction product of diethyltoluenediamine and an aromatic diamine.