Patent GB-802562-A (GB)
Title: Open flame curing of diolefin polymer oils
IPC: C08F36/04
Filed: 1957-02-12
Abstract: Coated articles are prepared by applying a coating of a polymer of a conjugated diolefine of 4 to 6 carbon atoms or a copolymer thereof with a vinyl aromatic hydrocarbon and contacting the coating directly with an open flame, preferably in the presence of oxygen; in a modification, a coating applied to one side only of a surface is cured by applying the flame to the uncoated side.  The polymer or copolymer (see Group IV (a)) may be liquid or solid and applied in solution or as a latex; it may be modified with maleic anhydride or by blowing oxygen or air through a solution and such oxidized polymers may have added thereto 1-49 per cent by weight based on polymer of a phenolic or amino-formaldehyde resin.  The coating may also contain 5-75 per cent, based on the weight of non-volatile matter in the film, of a pigment to form an enamel. The flame which is preferably non-luminous or oxidizing may be applied to the coated or uncoated side or to both sides simultaneously for times generally of 5 seconds to 4 minutes although up to 15 minutes may be necessary in some instances.  The coatings may be formed on surfaces which will withstand short exposures to flame temperatures, e.g. of 100-1100 DEG F. such as cold-rolled steel, tinplate, extruded pipe, aluminium or copper plate, heat-resistant glass and magnesium aluminium alloy. Coated steel can be formed into cans for food containers without rupture or failure of the coating.ALSO:Coatings of polymers of C4-C6 conjugated diolefines are cured by the direct action of an open flame; in a modification a coating applied to one side only of a surface is cured by applying the flame to the uncoated side.  The diolefine may be butadiene, isoprene or dimethylbutadiene and they may be copolymerized with styrene.  The polymers may be solid synthetic rubbers or liquid drying oils which are preferably prepared by solution polymerisation in the presence of an alkali metal catalyst or alternatively by emulsion polymerization or the use of hydrofluoric acid, BF3-ethyl ether complex or t-butyl hydroperoxide catalysts.  Solid polymers may be formed by mass, emulsion or peroxide polymerization.  The polymers may be modified with maleic anhydride or blown with air or oxygen in a hydrocarbon solvent at room temperature to 280 DEG  F. until up to 20 per cent oxygen is incorporated.  Such oxidized polymers may also be modified with 1-49 per cent by weight based on the polymer of a phenolic or amino-formaldehyde resin.  The polymer may be applied in solution or as a latex and may contain 5-75 per cent of a pigment based on the non-volatile content of the polymer to give an enamel.  The flame which is preferably non-luminous or oxidizing is then applied to the coated or uncoated side or to both sides simultaneously.  Times of up to 15 minutes may be necessary but 5 seconds to 4 minutes is generally sufficient.  If the polymer is applied in a solvent the solvent, if not previously evaporated, burns away.  Flame temperatures of 1000-1100 DEG  F. are referred to; the peak temperature of the coating should be below the ignition temperature of the film.