Patent · US Expired

Process for the preparation of ethylene copolymer

US4721761A · kind A · utility

27Cited by
0References
4Claims
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Assignee

Inventors

Key dates

Filing dateJul 28, 1986
Grant dateJan 26, 1988
Priority date
Expiry dateJul 28, 2006

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08F210/00
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

The present invention relates to an improved process for the preparation of an ethylene copolymer. In the copolymerization of a comonomer copolymerizable with ethylene and ethylene at a pressure of 500 to 3,000 kg/cm.sup.2 and at a temperature of 100.degree. to 350.degree. C. using an initiator in the presence or absence of a chain transfer agent, a gap between a packing and a retainer of an ultrahigh pressure pump for copolymerization is filled with a grease containing a polymerization inhibitor. The comonomer and a part or the whole of ethylene are mixed under an elevated pressure and then introduced into a reaction vessel. In accordance with the present invention, leakage of the comonomer from the packing of the pump, clogging of a conduit and breakage of the pump can be prevented, thus improving operation efficiency. Furthermore, the effect of diffusion of the comonomer into ethylene gas is attained sufficiently, thus enabling the production of a high-quality polymer having less gel content. This facilitates the reaction control, improving the reaction stability.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.