Patent GB-956056-A (GB)
Title: Improvements in or relating to the manufacture of foamed polyurethanes
Inventor: LORD FRANK WHITLEY
IPC: C08J9/00
Filed: 1961-10-02
Abstract: Foamed polyurethanes are made by the reaction of organic polyisocyanates with hydroxyl group-containing polymers containing at least two groups reactive towards isocyanate per molecule, in the presence of water and/or a liquid having a boiling point not exceeding 75 DEG C., and chemically inert towards water and isocyanate, or in the presence of a soluble polymeric reaction product obtained from the reaction of an aluminium alcoholate and a carboxylic acid. The reaction product may be used in amounts 0.2% to 5% by weight based on the hydroxyl group-containing polymer and is preferably the product from the reaction of aluminium isopropoxide and 2-ethylhexoic acid, and may be dissolved in the ester derived from the carboxylic acid and alcohol from the aluminium alcoholate as used to form the reaction product.  Tin carboxylates e.g. stannous octoate, organo-tin compounds e.g. dibutyl tin laurate and tertiary amines e.g. 4-dimethylamino pyridine, 1, 4-diazabicyclo (2:2:2) octane, dimethyl benzylamine, N-dimethyl-cyclohexylamine or mixtures thereof may be added as catalysts.  The hydroxyl group-containing polymer may be a secondary hydroxyl-ended polymer e.g. a polyester or polyesteramide, with M.W. 200-5,000, or a polyether such as one derived from propylene oxide with M.W. 400-600 and may be treated simultaneously with the organic polyisocyanate and water. The polyester or polyesteramide may be made from specifically disclosed aliphatic and aromatic dicarboxylic acids and di-, tri-, and polyhydric alcohols, or compounds containing more than two groups selected from hydroxyl, carboxyl, secondary and primary amino groups e.g. diethanolamine, trimeric acid, dihydroxystearic acid and tricarballylic acid; whilst for the preparation of polyesteramides, diamines and aminoalcohols are specified.  The polyethers may be polymers and copolymers of cyclic oxides e.g. 1, 2-alkylene oxides and may be linear or branch chain polymers, made by polymerizing an alkylene oxide with a glycol primary monoamine or polyhydroxy compounds (specified). Branched polyethers may also be copolymers of a cyclic oxide, as above, with a cyclic oxide having more than two functional groups e.g. diepoxides, glycidol, and 3-hydroxymethyloxacyclobutanes. The organic isocyanate preferred is a mixture of tolylene 2, 4- and 2, 6-diisocyanates (in ratio 80:20 and 65:35) but also disclosed are aliphatic diisocyanates e.g. hexamethylene diisocyanate, specified aromatic di-, tri-, and polyisocyanates. The low boiling point liquids are chemically inert towards isocyanates and water and have boiling points in the preferred range -40 DEG  to +50 DEG C. e.g. fluorinated alkanes such as CCl3F, CCl2F2, CCl2FH, CClF2H, CBr2F2, Cl2FC.CF2Cl, C2Cl2F4, C2F3H2Br or mixtures thereof or with low boiling hydrocarbons. These liquids may be employed in amounts 1 to 100% by weight of the hydroxyl group-containing polymer and water in amounts 1 to 10%. Additives may be surface active agents e.g. oxyethylated phenols, fatty alcohols, sulphated fatty alcohols and esters, alkyl and aryl polysiloxanes and block copolymers thereof with polyalkylene oxides, flame retardents such as b -trichlorethyl phosphate and antimony oxide, plasticizers e.g. tricresyl phosphate, colouring matter and fillers e.g. carbon black and silica. Aluminium alcoholates may be butoxide, propoxide and ethoxide whilst carboxylic acids may be ethanoic, stearic, oleic, naphthanic and cycloaliphatic acids. Specifications 806,113 and 809,309 are referred to.