Preparation of vesiculated core/shell polymeric particles
US5229209A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1991 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Mar 21, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31938
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for the manufacture of core/shell polymer particles comprises forming a core particle containing acid functionality, a first shell around said core of a copolymer of a nonionic monoethylenically unsaturated aromatic monomer and a copolymerisable polar monomer in an amount of at least 15% by weight of the copolymer and having a solubility in water at 20.degree. C. of at least 1% by weight and a second shell around said first shell of a polymer or copolymer of a nonionic monomer having a solubility in water at 20.degree. C. of less than 1% by weight and swelling the particle with a non-volatile alkali to generate one or more vesicles. Preferably each shell contains a polymer or copolymer of styrene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.