Patent GB-1148598-A (GB)
Title: Forming protective polymeric coatings on solid objects and producing self-supporting polymeric films
IPC: H04R19/04
Filed: 1966-06-14
Abstract: 1,148,598. Making hydrocarbon copolymer films. GULF RESEARCH & DEVELOPMENT CO. 14 June, 1966 [15 June, 1965], No. 26363/66. Heading B5B. [Also in Divisions B2 and C7] Self-supporting films are made by initiating gelation of a solvated polymer on a solid surface in an aqueous dispersion of the polymer said solvated polymer having a hydrocarbon chain structure, possessing at least two carboxy substituents per molecule and a degree of solvation such that neutralization of a minor proportion of the anionic sites of the carboxy substituents on the polymer molecules results in agglomeration of the polymer, accumulating a body of polymer gel adjacent to said solid surface, removing the accumulated polymer gel from the aqueous dispersion by removing the solid surface bearing thereon the polymer gel and removing water from the polymer gel. The polymer gel may then be separated from the solid surface and dried to yield an unsupported plastic film. The hydrocarbon chain structure may correspond to a uniform random copolymer of ethylene containing 67 to 99 mol per cent of units (a) and, correspondingly, 33 to 1 mol per cent of a mixture of units (b), (c) and (d); said units (b) constituting 5 to 70 mol per cent of the total of units (b), (c) and (d); said units (c) constituting 20 to 80 mol per cent of the total of units (b), (c) and (d) and said units (d) constituting a maximum of 75 mol per cent of the total units of (b), (c) and (d). Units (a) have the structure -CH 2 -CH 2 -, units (b) have the structure units (c) have the structure and said units (d) have the structure wherein R represents hydrogen or a hydrocarbon group, R 1  represents hydrogen or a cation, R 2  and R 3  independently represent hydrogen, hydrocarbon groups or hydroxyalkyl groups, and R 4  represents a hydrocarbon group. Units (b) and (c) are present in mol proportions sufficient to render the polymers dispersible in aqueous solvent systems. An electrically conducting solid article may be coated by electrodeposition or electrophoresis with the polymer by initiating the gelation of the solvated polymer at the positively charged surface of the article in the aqueous solvent system by the passage of an electric current from the article to a second electrode immersed in the aqueous dispersion of the polymer, removing the article bearing thereon the accumulated polymer gel from the aqueous solvent system and removing water from the coating of polymer gel on the article. A metal article may be coated with the polymer by initiating the gelation of the solvated polymer at the surface of the metal article in the aqueous solvent system by heating the metal article to a higher temperature than that of the solvated polymer before it is immersed in the dispersion. The article is then immersed in the dispersion for a time sufficient for it to become coated with the polymer gel, the coated article is removed from the dispersion and is heated to dehydrate the polymer coating. A fibrous particulate solid substance may be dispersed in the aqueous dispersion of the polymer so that a film or coating prepared from the system may have fibres dispersed therein.