Patent GB-634536-A (GB)
Title: Process for the preparation of reaction products of natural and synthetic rubbers with sulphur dioxide
IPC: C08F8/34
Filed: 1947-10-23
Abstract: Products for use in the manufacture of threads, tapes and films are obtained by reacting synthetic rubbers either in solid form or in solution with sulphur dioxide in the presence of a diazoamino compound with the general formula <FORM:0634536/IV (a)/1> in which R1, R2 and R3 are hydrocarbon or heterocyclic radicles, alkyl, arylamino, acyl, nitrile, amido, amino, sulphamido or iminamido groups, if desired substituted, and at most two of R1, R2 and R3 may be hydrogen and R3 may also be a metal.  The synthetic rubbers may be polymers of butadiene, methyl and dimethyl butadiene, pentadiene, chlorbutadiene and acetylene, and also copolymers of these compounds with isobutene, acetylene, vinyl-halides, vinyl esters, styrene, acrylic and methacrylic acids, unsaturated aldehydes, ketones or ethers including acrolein, pentane-4-one-2, and vinyl ethers. Specified diazoamino compounds are diazoaminobenzene, p-diazoaminotoluene, p-diazo toluene anilide, N-benzyl diazoaminobenzene, N-benzoyl diazoaminobenzene, N-p-tolyl diazoaminobenzene, benzene diazo dimethylamine, bis-(benzene)-diazo methylamine, N-phenylcarbamido diazoaminobenzene.  The velocity of the reaction may be increased by means of a metal nitrate such as lithium or silver nitrate.  In examples, the rubber is treated with the diazo compound and sulphur dioxide in the liquid or gaseous state at temperatures of about 0-20 DEG  C. for periods from 1 minute to 24 hours.  The reaction may be carried out in presence of vinyl chloride, styrene and propene compounds.  Softeners, fillers and pigments may be added during, before or after the reaction. Specification 572,574, [Group V], is referred to.ALSO:Products for use in the manufacture of threads, tapes and films are obtained by reacting natural or synthetic rubbers either in solid form or in solution with sulphur dioxide in the presence of diazoamino compounds with the general formula:- <FORM:0634536/V/1> in which R1, R2 and R3 are hydrocarbon or heterocyclic radicles, alkyl, arylamino, acyl, nitrile, amido, amino, sulphamido or iminamido groups, if desired substituted, and at most two of R1, R2 and R3 may be hydrogen and R3 may also be a metal.  The synthetic rubbers may be polymers of butadiene, methyl and dimethyl butadiene, pentadiene, chlorbutadiene and acetylene, and also copolymers of these compounds with isobutene, acetylene, vinylhalides, vinyl esters, styrene, acrylic and methacrylic acids, unsaturated aldehydes, ketones or ethers including acrolein, pentane-4-one-2, and vinyl ethers.  Specified diazoamino compounds are diazoaminobenzene, p. diazoaminotoluene, p. diazo tolueneanilide, N-benzyl diazaominobenzene, N- benzoyl diazoamino-benzene, N-p-tolyl diazoaminobenzene, benzene diazo dimethylamine, bis (benzene) diazo methylamine N-phenylcarbamido diazoaminobenzene.  The velocity of the reaction may be increased by means of a metal nitrate such as lithium or silver nitrate.  In examples the rubber is treated with the diazo compound and sulphur dioxide in the liquid or gaseous state at temperatures of about 0-20 DEG C. for periods from one minute to 24 hours.  Specification 572,574 is referred to.