Patent GB-1009876-A (GB)
Title: Improvements in or relating to foamed vinyl chloride polymer compositions
Inventor: GOULD REX WILLIAM
IPC: C08J9/30
Filed: 1962-09-13
Abstract: Foamed vinyl chloride polymer compositions may be manufactured by subjecting (i) a vinyl chloride paste polymer in the form of particles having air-filled cavities, (ii) a plasticizer for the polymer in an amount at least sufficient to wet the polymer and (iii) sufficient of a cationic or anionic surface-active agent to prevent the agglomeration of air bubbles entrapped in the cavities in the polymer particles, to a mixing action sufficient to coat the polymer particles with the plasticizer so as to entrap the air within the cavities but insufficient to cause disintegration of the particles. The foamed dispersion has substantially uniform cell distribution the individual cells having a size of not more than 150 microns, and it is preferred to use the polymer particles in the form of cenopheres or loosely agglomerated groups of cenospheres.  A homopolymer or a copolymer of vinyl chloride containing up to 25% by weight of other copolymerizable material may be used.  Suitable copolymerizable monomers include vinyl esters, acrylic esters and vinylidene chloride.  Examples of plasticizers are adipates, sebacates, azelates, phosphates, isomeric phthalates, epoxy plasticizers formed by the condensation of an epihalohydrin with a dihydric compound and polyesters such as those prepared from propylene glycol and adipic acid.  Anionic surface active agents are particularly suitable, especially metal salts of sulphonated petroleum fractions, alkali metal salts of alkyl sulphates or alkaryl sulphonates, metal salts of esters of sulphocarboxylic acids and metal salts of sulphated glycerides.  Examples of cationic surface-active agents are organic quaternary ammonium salts containing long chain hydrocarbon groups attached to the nitrogen atoms such as cetyl pyridinium chloride, oleamidoethyldiethyl ammonium chloride, cetyl trimethyl benzyl ammonium bromide and stearyl amidopropyl b -hydroxyethyl dimethyl ammonium nitrate. Up to 40 parts per 100 parts by weight of the paste polymer, of vinyl chloride polymers which are not paste polymers may be added to the composition to reduce the viscosity. The foamed dispersion may be gelled at temperatures between 150 DEG  and 170 DEG C. and may be used for the preparation of shoe soles, coating on to fabrics and cushioning materials.ALSO:A foamed vinyl chloride polymer composition which comprises (i) a vinyl chloride paste polymer in the form of particles having air filled cavities, (ii) a plasticizer for the polymer in an amount at least sufficient to wet the polymer, and (iii) sufficient of a cationic or anionic surface active agent to prevent the agglomeration of air bubbles entrapped in the air cavities, is subjected to a mixing action sufficient to coat the polymer particles with the plasticizer so as to entrap the air within the cavities but insufficient to cause disintegration of the particles, and the resulting dispersion is spread on to a cloth and gelled, preferably at a temperature between 150  DEG C. and 170  DEG C.  The dispersion is useful in the preparation of a cellular leathercloth and may be coated on to other fabrics and gelled to provide a "breathable" finish.  An example describes the coating of a cloth with a composition of a polyvinyl chloride paste polymer with a mixture of trixylyl phosphate, dibutyl phthalate and mixed phthalates of alkyl alcohols having from 7-9 carbon atoms as plasticizer and a mixture of calcium dodecyl benzene sulphonate, and calcium petronate as surface active agent.  After gelation at 160  DEG C. a cloth having a resilient foam coating is provided.