Process for the grafting of monomers onto polyolefins
US4612155A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1985 |
| Grant date | Sep 16, 1986 |
| Priority date | — |
| Expiry date | Jul 18, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F255/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A continuous process for the grafting of ethylenically unsaturated monomers onto homopolymers of ethylene and copolymers of ethylene and C.sub.4 -C.sub.10 higher alpha-olefins is disclosed. The process involves feeding to an extruder an admixture comprising (i) a major portion of the above polymer of ethylene, (ii) the monomer, (iii) 25-500 ppm of an organic peroxide and (iv) a minor portion of a normally solid thermoplastic polymer having a melting point of less than 185.degree. C. and a shear viscosity at 200.degree. C. and a shear rate of 400 sec.sup.-1 that is not more than 50% of that of the polymer of ethylene. The organic peroxide is in the form of a composition with the thermoplastic polymer. The admixture is mixed in a first zone at a temperature above the melting point of the polymers for at least ten seconds but for less than 25% decomposition of the peroxide and then in a second zone for a period that is at least four times the half-life of the peroxide. A grafted polymer having a melt index that is 20-100% of that of the polymer prior to grafting is obtained. The grafted polymer may be used in a variety of end-uses, for example, the manufacture of film, moulding of art…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.