GB752365A - Improvements in or relating to contact igniters - Google Patents

Abstract

752,365. Pyrotechnic igniters and compositions. MOSER, H. H. Feb. 24. 1954 [Sept. 1, 1953], No. 5469/54. Drawings to Specification. Classes 9(1) and 9(2) [Also in Groups XI and XII] A contact igniter operates by the holding of two bodies in surface contact with one another, one body being of oxidizing material and the other body being.a contact material therefor such that on surface contact between the two bodies there occurs a reaction with a relatively small generation of heat, the igniter comprising a third material which is ignitable through the surface contact of the two bodies and reacts thereby to increase the generation of heat whereby a combustible body can be ignited. Materials employed are hydrazine derivatives, particularly hydrazine salts, and hydroxylamine salts which are brought into contact with oxidizing materials such as permanganates, for example potassium or silver permanganate, iodic acid, silver difluoride, persulphuric acid and the higher oxides of silver in admixture.with semi-pyrophoric iron which acts as the third material. The materials are deposited, for example by impregnation or coating, on carrier substances such as fibrous substances, for example paper or cardboard, and/or thermoplastic synthetic substances, for example polyisobutylene or polymeric polyvinyl compounds in the form of polyvinyl ethers. The igniter may be applied to a fuse cord, wick, match, or the like for explosives, fireworks, torches, combustible materials, candles, firelighters, cigarettes, or an ignition strip of flash-light 'or a mixture of aluminium powder with an iron oxide as used for welding. In all cases at least, a part of the body to be ignited or caused to glow is coated or impregnated with a mixture of the oxidizing agents and the semi-pyrophoric iron and the ignition is effected by bringing the coated or impregnated part of the body into contact with a surface, for example the surface of a piece of cardboard, coated or impregnated with for example hydrazine salts. In an example 3.6 parts by weight of very finely pulverized potassium permanganate and 1.5 parts by weight of semi-pyrophoric iron are mixed in a mixing drum and made into a thin paste with a solution of polyvinyl acetate in benzene as an adhesive and comprising about 3 per cent of the mass.