GB877880A - Curable halogenated alpha olefin polymers - Google Patents

Abstract

Elastomeric vulcanizates of an amorphous alpha-olefin homo-polymer, as hereinafter defined, are made by halogenating the homopolymer, at a temperature of from 40 DEG -200 DEG C. with a halogenating agent in an aromatic diluent, to form an elastomer halogenated polymer having a halogen content of from 0,5-40 wt. per cent, isolating the polymer, and reacting it with a curing agent at elevated temperature to form the vulcanizate. The homo-polymer is defined as the polymer of an olefin containing at least three carbon atoms, a crystallinity of less than 25%, a softening point below 50 DEG C., a tensile strength of from 50-1,500 p.s.i., an apparent modulus of elasticity at 0 DEG C. of from 10,000-100,000 p.s.i., and an intrinsic viscosity in tetralin at 125 DEG C. at a concentration of 1 gram per litre of 0,4-3,5. Alpha-olefins mentioned are propylene, butene-1, pentene-1, hexene-1, heptene-1, or 3-methyl-1-butene. Specified halogenating agents are chlorine, bromine, dichloro-dimethylhydantoin, or N-bromo-succinimide. The aromatic diluent may be benzene, chlorobenzene, or o-dichlorobenzene. The halogenated polymers are isolated from the reaction mixture by adding an alcohol or a ketone to the mixture, or by steam stripping the mixture. Curing agents mentioned are the oxides, sulphides, nitrates, phosphates, sulphates, or organic acid salts of zinc, cadmium, magnesium, iron, or lead, dicumyl peroxide, copper, iron, amines, polyamines, dimethylylol formaldehyde resins, halogenated dimethylol phenol resins, sulphur, dithiocarbamates, thiuram sulphides, dithiomorpholines, quinone dioxime, red lead, and dinitrosobenzene. Prior to curing, fillers such as carbon black, silica, and mica may be added to the halogenated polymer, together with conventional antioxidants and softeners, such as oils derived from coal tar, pine tar, and/or petroleum. The cured halogenated polymers may be used for making hoses, gaskets, tyres, and boots.