Voided latex particles
US11384216B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 2019 |
| Grant date | Jul 12, 2022 |
| Priority date | — |
| Expiry date | Jul 10, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K7/22
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.