Patent GB-604371-A (GB)
Title: Process of preparing stable emulsions of water-insoluble resins or cellulose derivatives
IPC: C09K23/00
Filed: 1945-06-25
Abstract: Solutions in a volatile, water-immiscible solvent of a water-insoluble natural resin, synthetic condensation resin, polyvinyl acetal resin or cellulose derivative are dispersed in an aqueous medium containing a surface-active agent, and emulsifying agents comprising at least one water-soluble polyvinyl compound and at least one natural hydrophillic colloid selected from the gums and algae, and the volatile solvent distilled off to produce stable emulsions.  A water-soluble cellulose derivative is preferably added. Surface-active agent and total emulsifying agent concentrations of respectively 0.03-0.6 per cent and 1.7-3.8 per cent by weight of the original water are preferred. The surface-active agent is preferably anionic and may be one of the "Aerosols" (sodium sulphonates of alkyl succinic esters or alkyl naphthalene), "Aresklene" (dibutyl phenyl phenol sodium disulphonate), fatty acid soaps of hydroxyethyl ethylene diamine, higher alcohol sodium sulphates, "Merpentine" (sodium alkyl naphthalene sulphonate) and anionic alkyl-aryl type wetting agents.  The solvent may be benzene, toluene, xylene, ligroin, butanol, dichlormethane, ethylene dichloride and chloroform. The gums or algae may be gum arabic, tragacanth, acacia, caragheen, "Somasel," or agar-agar.  The soluble polyvinyl compounds may be acetals or ethers or partly hydrolysed polyvinyl esters, preferably acetates.  Methyl, benzyl or glycol cellulose derivatives may be used.  Specific examples describe the emulsification of polyvinyl formal and butyral, phenol formaldehyde resin, ethyl cellulose, rosin and gum dammar.  Gum copal and polyvinyl propional and benzal are also mentioned. Fillers, waxes, pigments, plasticisers, modifying solvents, film modifiers and filming agents, e.g. diacetin or acetonyl acetone may be added.  The emulsions are useful for coating or impregnating wood, leather, cloth, cellulose material, metals or in making laminated wood products.  Particle size is greatly affected by the emulsifying technique, rate of solvent addition, rate of distillation and agitation, and concentrations of agents, details of which are given.ALSO:Solutions in a volatile, water immiscible solvent of a water insoluble synthetic condensation resin, polyvinyl acetal resin or cellulose derivative are dispersed in an aqueous medium containing a surface active agent, and emulsifying agents comprising at least one water soluble polyvinyl compound and at least one natural hydrophilic colloid selected from the gums and algae, and the volatile solvent distilled off to produce stable emulsions.  A water soluble cellulose derivative is preferably added.  Surface active agents and total emulsifying agent concentrations of respectively 0.03-0.62 and 1.7-3.8 per cent by weight of the original water are preferred.  The surface active agent is preferably anionic and may be one of the "Aerosols" (sodium sulphonates of alkyl succinic esters or alkyl naphthalene), "Aresklene" (dibutyl phenyl phenol sodium disulphonate), fatty acid soaps of hydroxyethyl ethylene diamine, higher alcohol sodium sulphates, "Merpentine" (sodium alkyl naphthalene sulphonate) and anionic alkyl-aryl type wetting agents.  The solvents may be benzene, toluene, xylene, ligroin, butanol, dichlormethane, ethylene dichloride and chloroform. The gums or algae may be gum arabic, tragacanth, acacia, caragheen, "Gomagel," or agar agar. The soluble polyvinyl compounds may be acetals or ethers or partly hydrolysed polyvinyl esters preferably acetates.  Methyl, benzyl or glycol cellulose derivatives may be used.  Specific examples describe the emulsification of polyvinyl formal and butyral, phenol formaldehyde resin and ethyl cellulose. Polyvinyl propional and benzal are also mentioned.  Fillers, waxes, pigments, plasticizers, modifying solvents, film modifiers and filming agents, e.g. diacetin or acetonyl acetone may be added. The emulsions are useful for coating or impregnating wood, leather, cloth, cellulosic material, metals or in making laminated wood products.  Particle size is greatly affected by the emulsifying technique, rate of solvent addition, rate of distillation and agitation, and concentrations of agents.  In examples: (1) and (3) where the polyvinyl formal solution is replaced by a 50 per cent solution in benzene of a phenol-formaldehyde resin the composition comprises 1000 parts water, 3 per cent (on the water) of a partially hydrolized polyvinyl acetate containing 20 per cent residual acetate groups, .25 per cent partially hydrolysed cellulose methyl ether, .5 per cent gum tragacanth, .4 per cent sodium salt of the sulphonic acid of dioctyl succinate; (9) water, hydrolyzed polyvinyl acetate, gum tragacanth, sodium salt of sulphonic acid of dioctyl succinate and a phenol-aldehyde resin dissolved in benzene.