International Paper Company

Brian Boyars

Peter Matthew Froass

Yaoliang Hong

Mark Edward Fagan

Andrew Klein

Kosaraju Krishna Mohan

Victoria Laurentia Dimonie

Eric Scott Daniels

Edward David Sudol

Christopher D Anderson

Expandable microspheres formed by suspension polymerization using a shot growth method are provided. The microspheres are formed of a continuous, gas impermeable shell surrounding a blowing agent. The shell includes a first polymer layer formed from primary monomers and a second layer that includes a chemically reactive monomer or a high Tg monomer. To form the microspheres, the primary monomers are polymerized in a reaction vessel to an approximate 90% polymerization, at which time a secondary monomer that is either a monomer having a Tg of at least 85&#xb0; C. or a chemically reactive monomer, is added to the reaction vessel to drive the polymerization reaction to completion. The outer layer thus contains either a larger amount of the high Tg monomer or a chemically reactive monomer that possesses the ability to covalently bond a cationic species. The microspheres may be used in papermaking processes to increase the paper bulk.

Expandable microspheres and methods of making and using the same

Growing community of inventors

Las Vegas, NV, United States of America

Brian Boyars