| 摘要 |
Vinyl chloride polymers are crosslinked by heating in the presence of a polysulphonazide of formula R(SO2N3)x where x is an integer greater than 1 and R is an organic radical inert to the crosslinking reaction. Expanded products may be obtained by incorporating a blowing agent operative before or during the crosslinking reaction. Specified polymers are polyvinyl chloride and copolymers of vinyl chloride with vinyl acetate, vinylidene chloride, acrylonitrile and 1,2-ethylene dicarboxylic acid alkyl esters such as diethyl fumarate and diethyl maleate. The polysulphonazide may be 1,7 - heptane bis - (sulphonazide), 1,10 - bis - (sulphonazide), 1,3 - benzene bis - (sulphonazide), 1 - octyl - 2,4,6 - benzene tri - (sulphonazide), 4,41 - diphenylmethane bis - (sulphonazide), 4,41 - diphenyl ether bis - (sulphonazide), azides of chlorosulphonated petroleum hydrocarbons, 4,41 - bis - octadecyl biphenyl-3,5,31,51 - tetra - (sulphonazide), 4,41 - diphenyl disulphide bis - (sulphonazide), 7 - oxatridecane - 1,13 - bis - (sulphanazide), 6 - thioundecane - 1,11 - bis - (sulphonazide), 1,6 - bis - (41 - sulphonazidophenyl) hexane, 2,7 - naphthalene bis - (sulphonazide), poly - (ethylene sulphonazide), poly-(sulphonazidomethyl styrene) and copoly - (sodium ethylene sulphonateethylene sulphonazide). The blowing agent may be chemical, e.g. azo, introso and sulphonyl hydrazide compounds, or solvent, e.g. hydrocarbons or halogenated hydrocarbons. The polymer, crosslinking agent and blowing agent may be mixed by milling or extrusion, in solution, or by adding the agents to a polymer dispersion, e.g. a plastisol. Extenders, fillers, pigments, plasticizers, processing aids and stabilizers may also be incorporated. Examples describe the crosslinking with 1, 10-decane bis-(sulphonazide) of (1) a vinyl chloridevinyl acetate copolymer; (2) and (3) polyvinyl chloride; compositions comprising polyvinyl chloride, dibasic lead phthalate and (4) and (5) glycol adipate, (6) and (7) dioctyldecyl phthalate and (8) and (9) chlorinated polyethylene; and (12) a plastisol comprising polyvinyl chloride, glycol adipate and dibasic lead phthalate; the crosslinking with the azide of chlorosulphonated petroleum hydrocarbons of compositions comprising (10 and (11) polyvinyl chloride, glycol adipate and dibasic lead phthalate; and the preparation of flexible foams from plastisols comprising polyvinyl chloride, 1,10-decane bis-(sulphonazide), glycol adipate, dibasic lead phthalate and (13) and (14) epoxidized soya oil and azodicarbonamide, (15) p, p1-oxy-bis-(benzene sulphonyl hydrazide) and (16) N,N1-dinitrosopentamethylene tetramine. |
