GB893273A - Improvements relating to articles comprising solid reaction products derived from organic isocyanates and the like - Google Patents

Abstract

A method of producing an article consisting in part of a solid reaction product derived from (a) an organic compound having at least two -NCX radicals in the molecule, where X represents in the case of each radical either an oxygen atom or a sulphur atom, and (b) an organic polyether or polythioether having a molecular weight (or at least an average molecular weight) within the range 300 to 10,000 and having in each of its molecules at least two hydroxyl, amino or other groupings reactive with compound "(a)", comprises preparing one or more dispersions in an aqueous medium of material that will yield the solid reaction product, bringing the dispersion(s) into association with the other constituents of the article in question and then allowing reaction of the material to yield the solid reaction product. The dispersed material may be in the form of a prepolymer. The -NCX groups of compound "(a)" or of the prepolymer may be masked or blocked. The polyether or polythioether can be used in admixture with a polyester. In examples prepolymers are prepared from polypropylene glycol (M.W. 750) alone and with trimethylolpropane and toluene diisocyanate, in the presence of acid butyl phosphate, and in one case the product is reacted with phenol. Portions of the syrups were poured into rapidly stirred sodium dioctyl sulphosuccinate and the dispersion passed through a homogenizer. The dispersion was mixed with (4) short fiber asbestos floc, sand and lead chromate pigment which was trowelled on to a flat surface and set hard; (5) natural rubber latex, to give a mixture which set hard at 70 DEG C. Another portion of mixture was precipitated with ammonium sulphate and sulphur cured; (6) a similar procedure was carried out with a styrene-butadiene rubber latex; (7) a dispersion as used in (4) is mixed with natural rubber latex containing foaming and curing agents and the foam rubber obtained is cured. The dispersions can also be used for coating metals or fabrics, or bonding hair and the crumb materials of Specification 869,624 to form upholstery components. A body of foam rubber may be surfaced with a solid reaction product of components "(a)" and "(b)".ALSO:A prepolymer syrup obtained by reacting a polypropylene glycol and toluene-2 : 4- and 2 : 6-diisocyanates is heated with 20% of phenol and after cooling the product is dispersed, by rapid stirring, in a 2% solution of sodium dioctyl succinate at 0 DEG C. The dispersoin is then passed through a hand homogeniser. Equal volumes of the disperison and of rubber latex containing foaming and curring agents are mixed and the mixture is converted to a foam and cured. The use of the prepolymer dispersion in forming non-porous products is also described (see Group IV(a)). Specification 869,624 is referred to.