Small particle size polyester/acrylic hybrid latexes
US6001922A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1997 |
| Grant date | Dec 14, 1999 |
| Priority date | — |
| Expiry date | Aug 15, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F265/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention provides the preparation of water-dispersible polyester/acrylic hybrids via a two-stage emulsion polymerization process. For example, methacrylic acid and/or 2-hydroxyethyl methacrylate are copolymerized with styrene/acrylic monomers to yield a relatively hydrophilic and hydro-plasticized first stage. Subsequent additions of hydrophobic monomers to this first stage "seed" results in an inversion of the latex such that the more hydrophilic first stage is at the particle surface. This results not only in improved stability of the resulting latex without the use of additional surfactants, as evidenced by the production of reduced amounts of coagulum, while it also offers relatively low minimum filming temperatures due to the hydroplasticization of the shell of the particle. Furthermore, the use of the water-dispersible polyester results in extremely fine latex particle sizes which can significantly enhance coating properties such as film gloss and clarity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.