Patent GB-794755-A (GB)
Title: Improved polyurethane plastics and method of making the same
IPC: C08G18/76
Filed: 1955-10-06
Abstract: A process for producing polyurethane plastics comprises reacting a compound containing a plurality of reactive hydrogen atoms with a second component which is either (a) a diisocyanate of the formula <FORM:0794755/IV (a)/1> in which A is a dialkyl-methylene, alkylcyclohexyl - methylene, dicyclohexyl - methylene, cyclohexylidene or alkyl-substituted cyclohexylidene residue and in which R1 and R2 are hydrogen or halogen atoms or alkyl groups, or (b) a reaction product of said diisocyanate with a polyfunctional alcohol, polyfunctional amine, hydroxy amine, hydroxyl polyester, polyesteramide, or polyalkylene ether, said reaction products containing at least two NCO groups; or (c) a masked polyisocyanate. The masked polyisocyanates are prepared from the diisocyanates and their reaction products defined at (a) and (b) above by reaction with phenols or compounds with reactive methylene groups such as diethyl malonate.  Compounds containing a plurality of hydrogen atoms specified are linear or branched hydroxyl polyesters prepared from di- and/or polycarboxylic acids such as succinic adipic, phthalic and thiodipropionic acids, and di- and/or polyhydric alcohols such as ethylene glycol, propylene and butylene glycols, glycerol, trimethylol propane, hexanetriol and quinitol.  Modified alkyd resins, e.g. from saturated or unsaturated fatty acids, hydrogen products of ethylene-carbon monoxide copolymers, epoxy resins, isocyanatemodified polyesters still containing hydroxy groups, water, di- or polyhydric alcohols, di- or polyamines, hydroxy-amines and carboxylic acid amides are also suitable.  The isocyanate can be used in amount from 50 to 150 per cent of that necessary for reaction with all the active hydrogen.  Reaction may be accelerated by activators such as tertiary amines, phenates or heavy metal salts soluble in organic solvents or retarded by such compounds as acetic acid or acetyl chloride.  Dyestuffs, fillers, plasticisers, synthetic polymers and cellulose derivatives can be added to the components. In examples: (1) 4,41-diphenyl dimethylmethane diisocyanate and 1-trimethylol propane are reacted in ethyl acetate and the solution is applied to a support, giving a brittle film on exposure to moisture; (2) an isocyanate modified polyester (prepared by reacting 4,41-diphenyl dimethylmethane diisocyanate with a hydroxypolyester from adipic acid and diethylene glycol and a little trimethylol propane) is reacted in ethyl acetate with the reaction product of 4,41-diphenyl dimethylmethane diisocyanate prepared in Example (1) in the presence of an accelerator obtained by reacting 1 mol. of N-methyldiethanolamine and 2 mols. of phenyl isocyanate; (3) an ethyl acetate solution of a hydroxypolyester prepared from adipic acid, phthalic anhydride and trimethylolpropane is reacted with a reaction product of 4,41-diphenyldimethyl-methane diisocyanate and trimethylol propane still containing -NCO groups; (4) a hydroxy-polyester from adipic acid, phthalic acid and trimethylolpropane is reacted with 1,11-di-(4-isocyanatophenyl) cyclohexane to form a coating suitable for lacquering refrigerators; (5) diphenylmethylethylmethane-4,41-diisocyanate is reacted with trimethylol propane and the product is mixed with an ethyl acetate solution of the hydroxypolyester employed in Example (4). Diphenylmethyl-isopropylmethane - 4,41 - diisocyanate or diphenyl - diethyl - methane 4,41 - diisocyanate can be similarly employed; (6) an ethyl acetate solution of a hydroxypolyester from adipic acid, trimethylolpropane and 1,3-butylene glycol is mixed with (a) 3,31-dimethyl-diphenyl-dimethylmethane-4, 41-diisocyanate or (b) 3,31-dichlorodiphenyl - dimethylmethane - 4,41 - diisocyanate to give a product which when applied to plywood has good bonding properties.