| 摘要 |
Improved buoyancy and increased fineness and uniformity of the cell division of the cellula resins prepared as described in Specification 598,642 by allowing to react at 20-30 DEG C. an aqueous mixture of a thermosetting phenolaldehyde condensate, a water-soluble salt of carbonic or nitrous acid, and a water-soluble sulphonic acid, are obtained by substituting for the carbonate or nitrite gas generators an organic solvent for the condensate which is volatile under the reaction conditions. Part of the water-soluble sulphonic acid may be substituted by hydrochloric or sulphuric acid. A polymerizable organic compound containing a -HC = CH- or a CH2 = C< group is preferably added to the reactants. There are specified as: (1) solvents-isopropyl ether, solvatone, dioxane, methyl ethyl ketone, methylal, methyl acetate, carbon tetrachloride, ethylene dichloride, butanol, n-propyl acetate, toluene, n-butyl ether, carbon tetrachloride; (2) sulphonic acids-those derived from benzene, toluene, naphthalene, camphor, naphthol, anthraquinone, halogenated benzene, cresol, xylenol and other substituted phenols, naphthylamine, dihydroxynaphthalene and dihydroxy benzene; water-soluble sulphonic acids derived from aliphatic hydrocarbons, petroleum oils and tars; (3) as vinyl &c. type polymerizable compounds-diallyl diglycol dicarbonate, alkyd-styrene &c. polymers as described in U.S.A. Specifications 2,443,736 and 2,443,741; dienes, e.g. butadiene, vinyl substituted aromatics, e.g. styrene, acrylic acid and its derivatives; ethylenically unsaturated halogenated hydrocarbons. The phenolic resin is prepared as described in Specification 598,642 and in Example (3) 30 parts of the resin are mixed with 1.5 parts of the polyester of dipropylene glycol maleate in styrene solution (containing 1 per cent benzoyl peroxide), 1.5 parts isopropyl ether, 0.4 parts polyethylene ethers of sorbitan mono-laurate and 3 parts 50 per cent phenol sulphonic acid; after standing 30 seconds at 25-28 DEG C. the foam rose and solidified. Fillers, e.g. clays, walnut shell flour, carbon black, mica, ground phenolic foam, may be added. Surface-active materials in weight from 0.05-10 per cent of the liquid resins are used, the following being specified:-polyethylene ethers of sorbitan monoester of a fatty acid; the stearic or oleic esters of polyethylene glycol; dimethyl amine oxides; alkyl dimethyl benzyl ammonium chloride sulphonated ethers and their quaternary ammonium salts; the oxazaline from oleic acid and 2-ammo-2-methyl-1,3-pentanediol. The cellular resins may be used for buoyancy operations, e.g. for filling blister voids in ships; in refrigerators, air-conditioning, oil refinery, acoustical electrical apparatus. |
