Preparation of aqueous polymer dispersions having a polymer content of up to 75% by weight
US4371659A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1981 |
| Grant date | Feb 1, 1983 |
| Priority date | — |
| Expiry date | Mar 20, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2/24
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Aqueous polymer dispersions containing up to 75% by weight of polymer are prepared advantageously by emulsion copolymerization in the presence of conventional anionic emulsifiers, polymerization initiators and small amounts of polymerization inhibitors, at conventional polymerization temperatures, by copolymerizing at least two monomers A, which per se are not copolymerizable with one another, mixed with from 60 to 95% by weight of at least one monomer B, which is copolymerizable with both monomers A, in the presence of a polymerization inhibitor, by the emulsion feed process, wherein (a) the initial aqueous phase at the start of the monomer emulsion feed contains from 0.01 to 0.5% by weight of anionic emulsifier and from 1 to 7% by weight of water-soluble salts, (b) the monomer emulsion contains from 50 to 500 ppm of polymerization inhibitor, (c) from 1 to 10% by weight of the monomer emulsion is added, within the first 1/2 hour from the start of the feed, at an increasing rate per unit time, to the initial charge and thereafter (d) the remaining monomer emulsion is added in a conventional manner in accordance with the rate of polymerization of the monomers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.