Heat-shrinkable, tubular foam
AssigneeSumitomo Chemical Company, Limited
InventorsMasashi Aoshima, Tadashi Jinno, Naohiro Yoshida
Life of this patent
Estimating the term…
Abstract
A heat-shrinkable, tubular foam can be produced from a composition which comprises 100 parts by weight of an ethylene-.alpha.-olefin-nonconjugated diene copolymer, 1 to 20 parts by weight of a foaming agent, 5 to 100 parts by weight of a thermoplastic resin having a Vicat softening point of 50.degree. to 200.degree. C., and up to 10 parts by weight of a crosslinking agent, by shaping the composition into a tube, crosslinking and foaming the tube and pressurizing the tube in the interior to inflate it. This heat-shrinkable, tubular foam is best suited for jacketing pipes, hoses, and the like.
Claims10
A heat-shrinkable, tubular foam produced by the steps of:
- (i) extruding a composition comprising 100 parts by weight of an ethylene-alpha-olefin-nonconjugated diene copolymer;
- 1 to 20 parts by weight of a foaming agent and 5 to 100 parts by weight of at least one thermoplastic resin having a Vicat softening point of from 50.degree. to 200.degree. C. selected from the group consisting of polyethylene, ethylene-alpha-olefin copolymers, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, ethylene-methacrylate copolymer, polypropylene, propylene copolymers and styrene-butadiene block copolymer to obtain a tube,
- (ii) heating the tube so as to crosslink and foam the tube,
- (iii) pressurizing the crosslinked, foamed tube in the interior to radially inflate it while keeping the crosslinked, foamed tube at a temperature not lower than the melting point of the thermoplastic resin, to obtain an inflated tube, and
- (iv) immediately cooling the inflated tube, the steps being carried out continuously.
Dependencies are inferred from the claim text.