Patent GB-855933-A (GB)
Title: Improvements in the production of cellular materials
Inventor: WILSON GORDON DAVEY
IPC: C08J9/00
Filed: 1957-10-30
Abstract: In making foamed plastisols, an inert gas or a volatile inert liquid is dispersed under superatmospheric pressure in a closed container throughout the plastisol which comprises, in addition to a vinyl chloride polymer and a plasticizer, a small proportion of an alkali metal or alkaline earth metal alkaryl sulphonate soluble in the plasticizer.  The plastisol is discharged from the container, by the pressure, in the form of an ungelled foam, which is then gelled by heat, e.g. incompletely gelled by radio-frequency heating and then completely gelled in a hot-air or infra-red oven.  The polymer may be polyvinyl chloride or a copolymer of vinyl chloride with a minor proportion of vinyl acetate or vinylidene chloride.  Specified inert gases are: carbon dioxide, nitrous oxide, dichlorodifluoromethane and dichlorotetrafluoroethane.  Specified inert liquids are: monofluorotrichloromethane, 1, 1, 2-trifluoro-1, 2, 2-trichloroethane and dichlorodifluoromethane at a temperature of 5 DEG C. and a pressure of 40 lb. sq. inch.  Specified plasticizers are: tricresyl phosphate, n-butanol diesters of adipic, sebacic and phthalic acid, 2-ethyl hexanol, 3. 5, 5-trimethylhexanol, a mixture of aliphatic alcohols containing seven to nine carbon atoms per molecule, polypropylene adipate and sebacate, and a dispersion of calcium stearate in dinonylphthalate.  Calcium carboxate may be added to the plastisol.  The alkaryl sulphonate is, preferably, in solution in a light mineral oil.  The amount of alkaryl sulphonate may be between 0,5 and 6% by weight of the vinyl chloride polymer.  Specified alkaryl sulphonates are: a solution containing 40% by weight of the calcium salt of an alkaryl sulphonic acid obtained as a by-product in the sulphuric acid refining of petroleum, a solution containing a mixture of the sodium, calcium or barium salts of di-o- and di-p-dodecyl benzene monosulphonic acids and a solution containing the calcium salts of a mixture of dodecyl benzene sulphonates. Specification 737,367 is referred to.ALSO:In making foamed plastisols, an inert gas or a volatile inert liquid is dispersed under super-atmospheric pressure in a closed container throughout the plastisol which comprises, in addition to a vinyl chloride polymer and a plasticiser, a small proportion of an alkali metal or alkaline earth metal alkaryl sulphonate soluble in the plasticiser.  The plastisol is discharged from the container, by the pressure, in the form of an ungelled foam, which is then gelled by heat, e.g. incompletely gelled by radio-frequency heating and then completely gelled in a hot-air or infra-red oven.  The polymer may be polyvinyl chloride or a copolymer of vinyl chloride with a minor proportion of vinyl acetate or vinylidene chloride.  Specified inert gases are: carbon dioxide, nitrous oxide dichlorodifluoromethane and dichlorotetrafluoroethane.  Specified inert liquids are: monofluorotrichloromethane, 1.1.2-trifluoro- 1.2.2-trichloroethane and dichlorodifluoromethane at a temperature of 5 DEG C. and a pressure of 40 lb. sq. in.  Specified plasticisers are: tricresyl phosphate, n-butanol diesters of adipic, sebacic and phthalic acid, 2-ethyl hexanol, 3, 5, 5-trimethylhexanol, a mixture of aliphatic alcohols containing seven to nine carbon atoms per molecule, polypropylene adipate and sebacate, and a dispersion of calcium stearate in dinonylphthalate.  Calcium carbonate may be added to the plastisol.  The alkaryl sulphonate is, preferably, in solution in a light mineral oil.  The amount of alkaryl sulphonate may be between 0,5 and 6% by weight of the vinyl chloride polymer.  Specified alkaryl sulphonates are: a solution containing 40% by weight of the calcium salt of an alkaryl sulphonic acid obtained as a by-product in the sulphuric acid refining of p  petroleum, a solution containing a mixture of the sodium, calcium or barium salts of di-o- and di-p-dodecyl benzene monosulphonic acids and a solution containing the calcium salts of a mixture of dodecyl benzene sulphonates. Specification 737,367 is referred to.