GB686672A - A method for the production of new or improved films and adherent coatings comprising nitrocellulose in solution in a solid polymeric resinous material and compositions for their production - Google Patents

Abstract

Films and adherent coatings are produced by forming, if necessary with the assistance of a volatile mutual solvent, a solution containing industrial nitrocellulose and a liquid polymerizable form of a dialkenyl ester of a dicarboxylic acid, said acid having in that portion of its molecule which is aliphatic one or more ethylenic carbon to carbon linkages, spreading out this solution into a film on a solid substrate and, after evaporating any volatile mutual solvent used, exposing the resulting film adhering to the substrate to polymerization conditions such as to favour oxidation. The ester may be derived from itaconic acid, maleic acid, dihydromuconic acid, methylene malonic acid, crotonylidene malonic acid, benzylidene malonic acid or furfurylidene malonic acid. The alkenyl groups of the ester may advantageously be allyl, but may also be methallyl. The solution may contain a cobalt drier, e.g. 0.1-1 per cent of cobalt naphthenate reckoned on the ester. In an example a quarter-second viscosity industrial nitrocellulose containing 12 per cent nitrogen is dissolved in 4 times its weight of diallyl itaconate, with the addition of 0.5 per cent of cobalt naphthenate based on the weight of ester, and is brushed on to a steel or glass substrate in the form of a film. The film is heated to 80 DEG C. for 4-6 hours. The resulting hard transparent colourless film adheres well to steel and to glass, but can be peeled off from glass after soaking in water for some time, whereby a self-supporting film may be obtained. Other examples are given of the production of films by similar methods using diallyl maleate, diallyl dihydromuconate (see Group IV (b)), the diallyl ester of crotonylidene malonic acid (see Group IV (b)) and diallyl methylenemalonate. Pigments, fillers, or plasticizers, more especially such as are unpolymerizable, ester solvents for nitrocellulose, e.g. dibutyl phthalate, and other effect materials may be included in the solutions. Specification 686,671 is referred to.ALSO:Diallyl dihydromuconate is prepared by esterifying dihydromuconic acid with allyl alcohol in presence of paratoluene sulphonic acid as an esterification catalyst. The diallyl ester of crotonylidene malonic acid is prepared by refluxing together crotonic aldehyde and diallyl malonate in presence of piperidine, washing with acidulated water, extracting with ether and fractionating the extract in vacuo after distilling off the ether. Both esters may be used in the manufacture of nitrocellulose lacquer solutions (see Group IV (a)).