Voided latex particles
AssigneeArkema Inc.
InventorsLily Liu, Wayne Devonport, Daniel Edward Stark, SR., Matthew F. Boudreaux
Life of this patent
Estimating the term…
Abstract
A process for forming voided latex particles is improved by combining swelling and polymerization of an outer shell into a single step. The process includes contacting multi-stage emulsion polymer particles comprising a core, at least one intermediate shell, with a swelling agent, and polymerizing an outer shell after said contacting with swelling agent wherein the core and the at least one intermediate shell are contacted with swelling agent in the presence of less than 0.5% monomer based on the weight of the multi-stage emulsion polymer particles, and substantially all of the swelling occurs during polymerization of the outer shell.
Claims22
A voided latex particle having a hollow interior, said voided latex particle comprising:
- (i) optionally a core comprising a hydrophilic component,
- (ii) at least one intermediate shell comprising, as polymerized units, one or more hydrophilic monoethylenically unsaturated monomer, one or more nonionic monoethylenically unsaturated monomer, or mixtures thereof, and
- (iii) an outer shell comprising a polymer having a Tg of at least 60° C. and bearing one or more functional groups selected from the group consisting of 1,3-diketo, amino, ureido, urea, hydroxyl, polyether, silane, phosphate, epoxy, fluorocarbon, aldehyde, ketone, acetoacetyl, functional groups or combinations thereof,
- wherein the voided latex particle is non-film-forming and opaque.
Dependencies are inferred from the claim text.