Reactive isocyanate-terminated prepolymers for binder applications

摘要

Elastomer composites are prepared by wetting particles of a natural or synthetic rubber with a liquid one-component moisture-curable resin composition and then exposing the wetted particles to moisture to cure the resin composition. The moisture-curable resin composition comprises (a) an isocyanate-terminated polyurethane prepolymer having an isocyanate content of from 0.5 to 12% by weight and (b) from 1 to 30%, based on the combined weight of components (a) and (b), of an epoxide or lactone compound having a molecular weight of from about 70 to about 1000 and which is miscible in the prepolymer at the relative proportions thereof that are present. In addition, the composition contains no more than 0.1% by weight of compounds having a primary or secondary amino group.

主权项

1. A process for preparing an elastomeric composite, comprising wetting particles of a natural or synthetic rubber with a liquid one-component moisture-curable resin composition and then exposing the wetted particles to moisture under conditions that the resin composition cures to form a binder phase which adheres the rubber particles together, wherein the moisture-curable resin composition comprises (a) an isocyanate-terminated polyurethane prepolymer having an isocyanate content of from 0.5 to 12% by weight and (b) from 1 to 30%, based on the combined weight of components (a) and (b), of an epoxide compound having a molecular weight of from about 70 to about 1000 and which is miscible in the prepolymer at the relative proportions thereof that are present, the composition containing no more than 0.1% by weight of compounds having a primary or secondary amino group and containing no more than 1% by weight of compounds that contain hydroxyl or thiol groups.