Patent GB-1422379-A (GB)
Title: Cellular products
IPC: C08L81/00
Filed: 1973-05-15
Abstract: 1422379 Cellular polysulphides CHEVRON RESEARCH CO 15 May 1973 [15 May 1972 26 March 1973] 23171/73 Heading C3C A rigid or semi-rigid cellular foam is produced by (1) reacting an aromatic carbocyclic or heterocyclic compound substituted by at least one functional group selected from -OH and -NHR, where R is hydrogen or C 1-6  alkyl, with molten sulphur to form a polysulphide, (2) cross-linking the polysulphide in the molten state with a cross-linking compound having at least two reactive sites capable of reacting with the -OH or -NHR group present in the polysulphide, and prior to completion of the crosslinking of the cross-linking of the polysulphide, (3) introducing a reagent system capable of generating CO 2  or COS gas in situ so as to form on subsequent cooling of the resulting molten material the required cellular foam. The crosslinking compound used in step (2) may be a polyisocyanate or polyisothiocyanate and may be added in the presence of an acid so as to form the gas generating reagent system of step (3). Examples are given in which a sulphur-phenol reaction product, or in case (d) an anilinesulphur reaction product, is (a) melted with sulphur, reacted with dithiodipropionic acid and then with 2,4-tolylene diisocyanate; (b) melted with sulphur, reacted with phosphorus pentasulphide and then dithiodipropionic acid, mixed with talc and reacted with diphenylmethane diisocyanate (DPMD); (c) as (b) except that the acid used is acrylic acid and no talc is used; (d) reacted with phosphorus pentasulphide, then dithiodipropionic acid, mixed with talc and reacted with DPMD; (e) heated with sulphur, followed by mercaptopropionic acid and DPMD; (f) heated with acrylic acid and then hexamethylene diisocyanate; (g) heated with sulphur and diglycolic acid, mixed with talc and reacted with DPMD; (h) heated with sulphur and talc and reacted with chloroacetic acid followed by DPMD; (i) heated with phosphorus pentasulphide and then sulphur, followed by reaction with a half-ester of maleic acid with a propylene oxide/trimethylol propane condensation product and then with DPMD; (j) heated with sulphur and then with the half-ester as in (i) together with monomethyl maleate, followed by DPMD; (k) heated with sulphur and phosphorus pentasulphide, followed by dithiodipropionic acid and the half-ester as in (i), followed by DPMD, talc being added after the acid or after the half-ester, and sulphur optionally being added before the acid; (1) heated with sulphur and phosphorus pentasulphide, followed by reaction with an alkenylsuccinic acid, triethyleneglycol half-ester and DPMD; (m) heated with sulphur and phosphorus pentasulphide, followed by reaction with dithiodipropionic acid, mixing with talc, reaction with the half-ester as in (i) and then with DPMD; (n) heated with a liquid polysulphide, then with sulphur and reacted with acrylic acid followed by a polyisocyanate pre-mix comprising DPMD, a condensation product as in (i) and methyl diethanolamine; (o) heated with sulphur and then a liquid polysulphide or polyoxyalkylene polysulphide, followed by reaction with acrylic acid and a pre-mix of DPMD, a propylene oxide, trimethylolpropane polymer and methyl diethanolamine; (p) heated with sulphur, reacted with a C 15  to C 18 -alpha olefin sulphonic acid and then with DPMD; or (q) heated with sulphur and reacted with citric acid, or an oligomerized fatty acid, and then with polymethylene polyphenylisocyanate. In some cases the top of the foam being produced in a mould is heated with an i.r. lamp as the foam rises.