Patent ID: 9382469
Filing Date: 2016-07-05
CPC Classification: C09K,E21B

Claim Text:
1. A process for the production of coated proppants, comprising the following steps: (a) mixing a proppant with a polyol component and an isocyanate component, wherein the polyol component consists of a phenolic resin and optionally one or more other hydroxy group-containing compounds, wherein the isocyanate component consists of an isocyanate having at least 2 isocyanate groups and optionally one or more other isocyanate group-containing compounds, and wherein x parts by weight of the isocyanate component are used with respect to 100 parts by weight of the polyol component, with x being about 105% to about 550% of the isocyanate value defined below: (b) curing the mixture obtained in step (a) by treatment with a catalyst; and (c) optionally repeating steps (a) and (b) one or more times,