Sequential heteropolymer dispersion and a particulate materal obtainable therefrom, useful in coating compositions as a thickening and/or opacifying agent
US4468498A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1982 |
| Grant date | Aug 28, 1984 |
| Priority date | — |
| Expiry date | Feb 25, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S525/901
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention is concerned with the production and use of water-insoluble particulate heteropolymers made by sequential emulsion polymerization in dispersed particles of which a "core" of a polymeric acid is at least partially encased in a "sheath" polymer that is permeable to a volatile base, such as ammonia or an organic amine, adapted to cause swelling of the core by neutralization. The aqueous dispersion of the acid-containing core/sheath particles is useful in making water-base coating compositions wherein it may serve as the binder or as a part thereof. In that use, the heteropolymer dispersion serves to provide desirable rheological control of the coating compositions when a volatile base is used to at least partially (to a pH of at least 6) neutralize the heteropolymer. Thus, the heteropolymer dispersion can serve as a thickener, or part thereof in coating compositions, such as water-base paints. For convenience of description herein, the terms "core", "sheath", and "core/sheath polymer" are frequently used to refer to the distinct functional components of the individual polymer particles of the essential "mode" of the heteropolymers of the present invention even th…
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