GB980139A - Improvements in or relating to the manufacture of polyurethane foams - Google Patents

Abstract

Polyurethane foam is produced by simultaneously interacting an organic polyisocyanate, a polyether containing secondary hydroxyl end groups and water, in the presence of a catalyst and a zinc carboxylate 0.01-1.0% of zinc carboxylate, e.g. acetate, butyrate, glycolate, octoate, 2-ethyl-hexoate, stearate, naphthenate and benzoate may be used. 1-100% of a liquid boiling below 75 DEG C., e.g. halocarbon, may be used in addition to 1-10% water. Neutralizing agents may be added. Polyethers may be derived from epichlorohydrin, 1:2-propylene oxide or 1:2 or 2:3 butylene oxides using a basic catalyst and may optionally be branched by adding ammonia, glycerol, hexane triols, trimethylol ethane, triethanolamine, pentaerythritol, sucrose, phenol-formaldehyde reaction products, monoethanolamine, diethanolamine, ethylene diamine, hexamethylene diamine, diethylene triamine, tolylene diamine, diamino-diphenylmethane, glycidol or 3 - hydroxymethyloxacyclobutanes. Polyisocyanates specified include aromatic and aliphatic di- and tri-isocyanates and reaction products of di-isocyanates with polyhydric alcohols, uretedione dimers, isocyanurate polymers and reaction products of phosgene and linseed amine/formaldehyde polymers. Catalysts specified are tertiary amines, salts of Pb, Sn, Cu, Hg, V, Ce, Mo, organometallic compounds, zinc dialkyl dithiophosphates, hydroxides of Na, K, Li, Ca, Sr, Ba, quarternary ammonium and phosphonium radicals and ternary sulphonium radicals. When basic catalysts are used a neutralizing agent may be added, e.g. sulphonyl esters, and benzene and toluene sulphonyl chlorides. Other additives may be: surface active agents, e.g. oxyethylated phenols, oleyl alcohol, sulphated methyl oleate, polyalkylsiloxanes, block copolymers thereof with polyalkylene oxides; flame retardants, e.g. b -trichloroethyl phosphate and SbO3; plasticizers, e.g. tricresylphosphate and dioctylphthalate; colouring matter; fillers, e.g. carbon black, and silica; colour stabilizers; whitening agents and antioxidants, e.g. tert-butyl-catechol and stearically hindered phenols. In examples, polyoxypropylene glycol (1,2) or oxypropylated glycerol (3,4), tolylene di-isocyanate and water are interacted in the presence of zinc 2-ethylhexoate (1,2) or zinc acetate (3.4), with other components specified above.