Patent GB-950876-A (GB)
Title: Improvements in or relating to the production of cellular polyurethane plastics
IPC: C08G18/54
Filed: 1961-05-01
Abstract: A process for making cellular polyurethane plastics comprises reacting under substantially anhydrous conditions an organic compound containing a plurality of carboxyl groups, having a molecular weight of at least 200 and an acid number of at least 20 with an organic polyisocyanate in the presence of a halohydrocarbon having a boiling point less than 150 DEG C. and a catalyst for the reaction between isocyanate and carboxyl groups. Blowing agents which split off gases at elevated temperatures, e.g. azoisobutyric acid nitrile, azodicarboxylic acid diethyl ester and dinitrosopentamethylene tetramine may be simultaneously employed. Suitable carboxylic compounds include linear or branched polyesters prepared from polyfunctional alcohols, aminoalcohols, hydroxy acids, amino-acids and polycarboxylic acids.  These include glycols, polyglycols, polymerised fatty acids, as well as more usual compounds which are listed. Aminocarboxylic acids used in preparing polyesteramides include a -amino mono- and dicarboxylic acids and a -amino-b -imidazole propionic acid.  The polyesteramide may be modified by acids e.g. lauric, palmitic, steric and linoleic acids.  Other specified compounds containing a plurality of carboxyl groups are reaction products of polycarboxylic acid anhydrides with hydroxy compounds, such as hydroxy polyesters, polyesteramides, polyesters, polythioethers and polyacetals; or products obtained by addition of such hydroxy compounds, degraded starch or acetyl cellulose with acrylonitrile or acrylic acid, followed by saponification (of the nitrile); polyalkylene glycol-ether polycarboxylic acids obtained by oxidation of polyalkylene glycol ethers; copolymerization products of fumaric acid, maleic anhydride, maleic acid half esters, crotonic acid and acrylic acid with styrene, isobutylene, vinyl acetate, vinyl chloride, vinylidene chloride, butadiene, isoprene and hexachlorocyclopentadiene. Also suitable are adducts of oleic acid with m-xylene, salicylic acid-formaldehyde condensates, carboxymethyl cellulose, copolymers of acrylic acid and linoleic acid, addition products of thioglycol and/or mercaptocarboxylic acids with compounds containing double bonds, for example polymers or copolymers obtained from butadiene or isoprene. Preferably the acid number of the polymers is 30 to 60, although values greater than 100 are referred to.  Polyisocyanates are listed.  They may contain small amounts of monoisocyanate. As activators there are specified; compounds of alkaline reaction containing the group-o]-Me+ wherein Me represents an alkali metal or quaternary ammonium group, e.g. alkali metal hydroxides, alcoholates, phenolates and carboxylic acid salts; tertiary amines; metal compounds soluble in organic media, such as dibutyl tin dilaurate, and tin-II-oleate.  Saturated and unsaturated halogenated hydrocarbons as blowing agents are listed.  There may be simultaneously used compounds which split off gases at elevated temperatures, e.g. azodiisobutyric acid nitrile, azodicarboxylic acid diethyl ester and dinitrosopentamethylene diamine. To the reaction mixture may be added stabilizers, emulsifiers, fireproofing agents, e.g. trichlorethyl phosphate and ammonium sulphate, carbon black, silica gel and metal powder fillers, and phthalic esters and chlorinated hydrocarbons as plasticisers.  In example (1) a polycarboxy compound is prepared by reacting a propylene oxide addition product of trimethylolpropane with dimerised linseed oil fatty acid. More of the polypropylene ether, containing sodium alcoholate, permethylated diethylene triamine, linear and branched phenylmethyl polysiloxanes is added followed by a solution of trichlorofluoromethane in toluylene diisocyanate. The mixture reacts to give a foam. In other examples the polycarboxylic compounds used are (2) and (3) reaction products of branched polypropylene glycol ether with succinic acid and of castor oil with dimerised linseed oil fatty acid; (4) to (7) polyesters prepared from (4) and (6) adipic acid, diethylene glycol and glycerol; (5) adipic acid, triethylene glycol and hexane-1, 2, 6-triol; (7) adipic acid, diethylene glycol and trimethylolpropane. Specification 769,682 is referred to.