| 摘要 |
1,248,256. Curing ethylene polymers. GENERAL ELECTRIC CO. 18 Oct., 1968 [1 Nov., 1967], No. 49625/68. Heading C3P. Cured polymeric articles are prepared by a method which comprises fabricating a curable composition comprising an ethylene polymer containing at least 50 mole per cent of ethylene, an organic peroxide curing agent and a mineral filler treated with 0À15 to 4 weight per cent of an organo silane; and passing the fabricated product through a non-aqueous heat transfer medium which is a gas, organic liquid, molten salt or salt solution at a temperature sufficient to effect curing. The ethylene polymer may be polyethylene or an ethylene/propylene or ethylene/vinyl acetate copolymer, optionally in admixture with halogen containing polymers, e.g. chlorinated or chlorosulphonated poly. ethylene or polyvinyl chloride. The curing agent may be dicumyl peroxide, 2,5-dimethyl- 2,5 - di - (t. butyl peroxy) hexane and 2,5-dimethyl - 2,5 - di - (t.butyl peroxy) hexyne-3, optionally with coagents such as polybutadiene. The filler may be aluminium, calcium or magnesium silicate, silica, aluminium oxide or titanium dioxide. Preferred organo-silanes are alkyl alkoxy silanes and vinyl alkoxyl silanes, e.g. ethyl triethoxysilane, n-hexyl trimethoxysilane, dodecyl trimethoxysilane, propyl trimethoxysilane, amyl triethoxysilane, vinyl tri - (2 - methoxyethoxy) silane, vinyl trimethoxysilane, vinyl triethoxy - silane and γ - methacryloxypropyl trimethoxysilane. The compositions may also contain antioxidants, e.g. polymerized trimethyl dihydroquinoline; lubricants, e.g. calcium stearate; flame retardants, e.g. antimony oxide and halogenated compounds; and colorants, e.g. carbon black. Suitable heat transfer media are polyalkylene glycols and esters thereof, glycerol and esters thereof, air, carbon dioxide and nitrogen. The method is particularly suitable for the manufacture of insulated wires and cables. |
