Core-shell particles synthesized through controlled free radical polymerization
US7344752B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2004 |
| Grant date | Mar 18, 2008 |
| Priority date | — |
| Expiry date | Dec 27, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F291/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention discloses a process for producing a core-shell polymer that comprises: (1) preparing a monomer solution which is comprised of (a) at least one monomer, optional one crosslinking monomer (b) a conjugate acid of a surfactant with a pKa of less than 14, and (c) a controlled free radical polymerization agent; (2) preparing an aqueous medium which is comprised of (a) water, and (b) a conjugate base of a weak acid wherein the pKb of the base is less than 14; and (3) mixing the monomer solution with the aqueous medium under conditions that result in the in-situ formation of an emulsifier to produce a polymerization medium, and (4) initiating free radical polymerization within the polymerization medium to produce a core polymer, wherein the core contains a free radical control agents, (5) adding a second monomer to the polymerization medium containing the core polymer, and (6) allowing polymerization to proceed in the presence of the free radical control agent to produce the core-shell polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.