Patent GB-692385-A (GB)
Title: Improvements in or relating to expanded cellular phenol-aldehyde resins and processes for producing them
IPC: C08L61/10
Filed: 1951-04-27
Abstract: A tubermoset cellular resin is made by admixing (1) 50-90 per cent of the product of reacting 1 mol. of phenol, a cresol or a xylenol with 1-3 mols. of formaldehyde or its polymers, acetaldehyde or furfuraldehyde in presence of alkali and water for 1/2 hour-20 hours at 50-115 DEG  C., followed by dehydration at pH3-11 to provide a product containing 3-25 per cent of water and having a viscosity of 1-250 poises, (b) 0.1-5 per cent of an acid stable, water soluble surface-active agent, (c) a solution of a peroxide equivalent to 1-20 parts of 100 per cent H2O2, (d) the balance, about 2-49 per cent consisting of hydrochloric, sulphuric, nitric, ortho-phosphoric, pyrophosphoric, a polyphosphoric, hydrobromic, hydriodic or trichloracetic acid or the water-soluble sulphonic acids; and allowing the mixture to expand, with or without the application of heat.  Specified catalysts for the phenol-aldehyde reaction are sodium-, potassium-, barium-, and calcium-hydroxides; calcium oxide; sodium and barium carbonates; sodium bicarbonate; ethylene diamine, propylene diamine, hexamethylenetetramine, aniline and ammonia. Prior to dehydration the reaction product may be acidified with lactic-, tartaric-, citric-, acetic-, oxalic-, malonic-, phenol sulphonic-, formic-, hydrochloric-, sulphuric- or phosphoric-acids or with maleic anhydride.  The resin may be plasticized by glycerol or aliphatic glycols having up to eight carbon atoms.  Specified surface active agents are the octadecyl phenol/ethylene oxide condensate; dodecyl phenol ethylene oxide; decyl phenol ethylene oxide sulphate; the polyethylene oxide ethers of octadecyl phenol and ricinoleic acid; octyl phenyl polyethylene glycol ether; sorbitan-monolaurate, monopalmitate, monostearate, tristearate and trioleate; polyoxyethylene sorbitan-monolaurate, tristearate and pentaoleate; polyoxyethylene sorbitol monolaurate; polyoxypropylene - ethylene sorbitan monolaurate; cetyl dimethyl benzyl ammonium chloride; octadecyl dimethyl benzyl ammonium chloride; octadecanol - 9 - dimethyl ethyl ammonium bromide and diisobutylphenoxyethoxy ethyl dimethyl benzyl ammonium chloride.  Specified peroxides are an aqueous solution of hydrogen peroxide and a solution of methyl ethyl ketone peroxide in dimethyl phthalate.  Other ingredients are up to 8 per cent of thermoplastic resins, e.g. polyvinyl butyral, polyvinyl acetate, the hydrolysis product of polyvinyl acetate, cellulose acetate, ethyl cellulose, polyvinylidene chloride, polymethacrylate and polymethymethacrylate; and up to 10 per cent of fillers, e.g. silica flour, wood flour, walnut shell flour, asbestos fibres, silica gel, acetylene black, aluminium powder, mica and cotton fibres.  A mixture of silica flour, asbestos fibres and aluminium powder may be used.  The cellular resin may be used for insulation purposes in refrigerators, for preparing boat hulls or floats and may be combined with surface shells or sheets composed of steel, aluminium, wood, cloth, glass fibre or resin laminates and used in the construction of e.g. air foils.  Specification 676,381 is referred to.