Production of sphere-formed powdery copolymers
US4309525A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1980 |
| Grant date | Jan 5, 1982 |
| Priority date | — |
| Expiry date | May 15, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2323/08
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A spherical powder of a hydrolyzed ethylene-vinyl acetate copolymer or its carboxyl modified product, is prepared by a method which comprises mixing 100 parts by weight of (1) a hydrolyzed product of an ethylene-vinyl acetate copolymer having 5 to 50% by weight of vinyl acetate group content or (2) a carboxyl modified product of the aforementioned hydrolyzed product obtained by reacting said hydrolyzed product with an unsaturated carboxylic acid or cyclic acid anhydride, with 10 to 100 parts by weight of an organic solvent capable of dissolving said hydrolyzed product or its carboxyl modified product, the solvent being not freely miscible with water and having a boiling point of not lower than 80.degree. C., 300 to 1000 parts by weight of water and 0.1 to 10 parts by weight of an alkylphenol ethylene oxide adduct having an HLB value of 10 to 20, emulsifying said mixture while it is maintained at a temperature of not lower than the softening point of said hydrolyzed product or carboxyl modified product, and decreasing the temperature of the system under stirring down to not higher than said softening point. The resultant powder is virtually spherical in its particle form, the partic…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.