The Dow Chemical Company

Dow Global Technolgoies LLC

Dow Silicones Corporation

James W Young, Jr

Bradley J Helmer

Lenin J Petroff

Kaoru Aou

Arjun Raghuraman

Juan Carlos Medina

Daniel G Moldovan

Sachit Goyal

Louis A Kuhlmann

A coated article, such as a proppant, includes a base substrate and one or more polyurethane based coatings on an outer surface of the base substrate. The one or more polyurethane based coatings including the reaction product of an isocyanate component that has at least one isocyanate and an isocyanate-reactive component that has one or more simple polyols and one or more polyether monols at a ratio from 1:18 to 18:1. An isocyanate index is greater than 0.2 and less than 1.0.

Polyurethane based proppant coatings

The invention relates to a fast hardening aqueous coating composition comprising from about 95 to about 99 weight percent of an anionically stabilized aqueous emulsion of a copolymer having a Tg of from about 0&deg; C. to about 40&deg; C., the copolymer containing two or more ethylenically unsaturated monomers, wherein from 0 to about 4 weight percent of the monomers are &agr;,&bgr;-ethylenically unsaturated aliphatic carboxylic acid monomers; from about 0.2 to about 5 weight percent of a polyimine having a molecular weight of from about 250 to about 20,000; and from about 0.2 to about 5 weight percent of a volatile base, wherein the composition has a pH from about 8 to about 11, and wherein a cast film of the composition has a hardening rate measurement rating of at least 5 within 20 minutes after casting under ambient conditions of temperature up to 30&deg; C. and relative humidity no less than 50 percent. Within the scope of the invention are a process for the preparation of a fast hardening aqueous coating composition, a fast hardening aqueous traffic paint, and a fast hardening migration resistant binder for composites.

Fast hardening aqueous coating composition and paint

The invention relates to a fast hardening aqueous coating composition comprising from about 95 to about 99 weight percent of an anionically stabilized aqueous emulsion of a copolymer having a Tg of from about 0.degree. C. to about 40.degree. C., the copolymer containing two or more ethylenically unsaturated monomers, wherein from 0 to about 4 weight percent of the monomers are .alpha.,.beta.-ethylenically unsaturated aliphatic carboxylic acid monomers; from about 0.2 to about 5 weight percent of a polyimine having a molecular weight of from about 250 to about 20,000; and from about 0.2 to about 5 weight percent of a volatile base, wherein the composition has a pH from about 8 to about 11, and wherein a cast film of the composition has a hardening rate measurement rating of at least 5 within 20 minutes after casting under ambient conditions of temperature up to 30.degree. C. and relative humidity no less than 50 percent. Within the scope of the invention are a process for the preparation of a fast hardening aqueous coating composition, a fast hardening aqueous traffic paint, and a fast hardening migration resistant binder for composites.

Polymers with a high glass transition temperature are used in cement additives to produce a portland cement mortar or concrete that does not have the initial stickiness typical of prior art polymer-modified portland cement compositions and does not form a crust on the surface when exposed to air drying, thus improving the working time of the mix. This simplifies equipment cleaning and permits the use of transit mixers for field applications of polymer-modified concrete. The properties of the mortar and concrete modified with these materials, both in the plastic and hardened state, are equivalent or superior to those of the currently available products which use film-forming materials. Within the scope of this invention are a redispersible powdered cement additive, a redispersible polymer powder and a ready-to-use portland cement composition, as well as related processes.

Growing community of inventors

Midland, MI, United States of America

James W Young, Jr