Process for the production of spray polyurethane elastomers and the elastomers produced by this process

摘要

Polyurethane elastomers having solids contents greater than 40% by weight are produced from a sprayable polyurethane-forming system composed of an isocyanate component and an isocyanate-reactive component. The isocyanate component has a solids content of from 40 to 80 wt. %, based on total weight of isocyanate component and is made up of at least one aromatic polyisocyanate having an NCO content of from 24 to 33%, a functionality of from 2 to 3 and at least one solid filler. The isocyanate-reactive component has a solids content of from 40 to 80 wt. %, based on total weight of the isocyanate-reactive component and is composed of at least one polyether polyol having a hydroxyl number of from 25 to 40 and a functionality of from 2 to 4, and at least one solid filler.

主权项

1. A polyurethane-forming composition suitable for the production of a polyurethane elastomer by spraying comprising:
a) an isocyanate component having a solids content of from 40 to 80 wt. %, based on total weight of isocyanate component and a viscosity at 25° C of less than 4,000 mPa.s comprising:
(i) at least one aromatic polyisocyanate having an NCO content of from 24 to 33%, a functionality of from 2 to 3 and(ii) at least one solid filler present in an amount sufficient to obtain the solids content of a)and b) an isocyanate-reactive component having a solids content of from 40 to 80 wt. %, based on total weight of the isocyanate-reactive component and a viscosity at 25° C of less than 4,000 mPa.s comprising:
(i) at least one polyether polyol having a hydroxyl number of from 25 to 40 and a functionality of from 2 to 4, and(ii) at least one solid filler present in an amount sufficient to obtain the solids content of b)wherein the total solids contents of a) plus b) is from 40 to 80 wt. %, based on total weight of the polyurethane-forming system.