Patent GB-715450-A (GB)
Title: Improvements in or relating to quaternary ammonium hydroxides as processing aids in foam rubber
IPC: C08J9/00
Filed: 1952-10-31
Abstract: Foam rubber having a fine continuous structure is produced by incorporating vulcanizing ingredients, a gelling agent, and a relatively small amount of a quaternary ammonium hydroxide having the formula <FORM:0715450/IV (a)/1> wherein at least one of R1 R2 R3 and R4 is an aliphatic hydrocarbon radical or a substituted aliphatic hydrocarbon radical having a carbon chain containing 4 or more carbon atoms and the remainder of R1 R2 R3 R4 are monovalent or two together are a divalent organic radical, or the nitrogen forms part of a heterocyclic ring, into a synthetic rubber latex, frothing the latex, allowing the frothed latex to set to an irreversible gel and thereafter vulcanizing the gelled froth.  The hydroxide may be added in an amount of 0.1 to 3.0 per cent. of the dry rubber content of the latex.  Many hydroxides are specified, typical of which are dodecyl tri-(2-hydroxyethyl) ammonium hydroxide, N-cetyl pyridinium hydroxide, N-lauryl imidazoline hydroxide, dodecyl trimethyl ammonium hydroxide, and cetyl dimethyl benzyl ammonium hydroxide. The synthetic rubber may be a polymer of 1.3-butadiene, piperylene, dimethyl butadiene, isoprene, or 2-chloro-1.3 butadiene, or copolymers of these monomers with each other or acrylonitrile, methacrylonitrile, alphachloroacrylonitrile, styrene, vinyl toluene, vinyl naphthalene, methyl acrylate, methyl methacrylate and acrylamide.  Sulphur, zinc mercaptobenzthiazole, benzothiazole disulphide, zinc diethyldithio-carbamate, piperidinium pentamethylene dithiocarbamate, and tetramethyl thiuram disulphide may be added, and the mix may be gelled by means of an alkali metal silico-fluoride, ammonium nitrate or ammonium sulphate.ALSO:Foam rubber having a fine continuous structure is produced by incorporating vulcanizing ingredients, a gelling agent and a relatively small amount of a quaternary ammonium hydroxide having the formula <FORM:0715450/V/1> wherein at least one of R1, R2, R3 and R4 is an aliphatic hydrocarbon radical or a substituted aliphatic hydrocarbon radical having a carbon chain containing 4 or more carbon atoms and the remainder of R1, R2, R3, R4 are monovalent, or two together are a divalent organic radical, or the nitrogen forms part of a heterocyclic ring into a natural or synthetic rubber latex, frothing the latex, allowing the frothed latex to set to an irreversible gel and thereafter vulcanizing the gelled froth.  The hydroxide may be added in an amount of 0.1 to 3.0 per cent. of the dry rubber content of the latex.  Many hydroxides are specified, typical of which are dodecyl tri (2 hydroxyethyl) ammonium hydroxide, N-cetyl pyridinium hydroxide, N-lauryl imidazoline hydroxide dodecyl trimethyl ammonium hydroxide and cetyl dimethyl benzyl ammonium hydroxide.  Sulphur, zinc mercaptobenzthiazole, benzothiazole disulphide, zinc diethylidithiocarbamate, piperidinium pentamethylene dithiocarbamate, and tetramethyl thiuram disulphide may be added, and the mix may be gelled by means of an alkali metal silico-fluoride, ammonium nitrate or ammonium sulphate.