Process for producing rubber-based graft copolymers
US4897462A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1989 |
| Grant date | Jan 30, 1990 |
| Priority date | — |
| Expiry date | Jun 9, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F279/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
In a process for producing a rubber-containing graft copolymer, which comprises bringing a latex of a graft copolymer comprising 60% to 90% by weight of a rubbery polymer and 40% to 10% by weight of a hard polymer, said graft copolymer latex being obtained by emulsion polymerizing a hard polymer-forming monomer in a latex of said rubbery polymer and having a minimum film-forming temperature of 75.degree. C. or less, into contact with an aqueous electrolyte solution under stirring, thereby to coagulate the latex, and recovering the precipitated graft copolymer, the improvement is disclosed such that the graft copolymer latex is subjected to slow coagulation so as to allow the graft copolymer to precipitate as substantially spherical particles, wherein the term "slow coagulation" refers to coagulation which proceeds at a milder rate than that of coagulation in which the aqueous electrolyte solution is hydrochloric acid and the pH of the latex during coagulation is 1.8 or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.