GB878150A - Improvements in or relating to the modification of polymers - Google Patents

Abstract

An isoolefin-diene copolymer having an average molecular weight of at least 200,000 and a mole per cent unsaturation of less than 5% is modified by forming an intimate mixture of 100 parts by weight of the copolymer with from 0,5-100 parts by weight of one or more conjugated diene, vinyl, vinylidene or allyl monomers and effecting polymerization of the monomeric material with the aid of a free-radical-generating catalyst. Copolymers specified are isobutylene-isoprene rubbers. Monomers specified are vinyl and vinylidene halides, acrylic and methacrylic acids and their nitriles, amides, C1C18 alkyl, including cycloalkyl, esters and esters with unsaturated and polyhydric alcohols, vinyl acetate, vinyl allyl and methallyl esters of saturated and unsaturated mono- and poly-carboxylic acids, divinyl benzene, styrene and alkyl derivatives thereof, vinyl pyridines, vinyl carbazole, mono- and poly-unsaturated ketones and ethers, acrolein, methacrolein, crotonaldehyde, butadiene, isoprene, dimethyl butadiene, cyclohexadiene and diallyl aryl phosphonates. Polymerization may be carried out in solution, aqueous emulsion or in bulk. Catalysts specified are organic and inorganic peroxides which may be used in conjunction with a reducing agent to form a redox system. The properties of the resulting products are determined by the nature of the modifying monomer. Products containing reactive hydrogen atoms may be reacted with diisocyanates or epoxy resins, e.g. those formed from epichlorohydrin and polyphenols or polyamines. The products find particular application as adhesives, for which purpose they are used in solution or latex form in admixture with substances such as phenoplasts, e.g. a resorcinolformaldehyde resin, aminoplasts, condensation products of amines with aldehydes and ketones, natural rubber, polybutadiene, butadiene copolymers, polystyrene, polyvinyl chloride and polymethacrylates. After application, e.g. to fibres, the adhesives are cured by heating.ALSO:Fibres and cords, e.g. those of rayon, cotton, nylon, polyacrylonitrile or polyethylene terephthalate, are coated with an adhesive comprising (1) an iso-olefin-diene copolymer having an average molecular weight of at least 200,000 and a mole per cent unsaturation of less than 5%, e.g. butyl rubber, which has been modified by polymerizing therewith an unsaturated monomeric material, e.g. unsaturated acids, amides, nitriles, esters, hydrocarbons (including unsaturated aromatic and dienic hydrocarbons), halogenated hydrocarbons, aldehydes, ethers, ketones and heterocyclic compounds (see Group IV(a)), in admixture with (2) a coating adhesive component such as a phenoplast, e.g. a resorcinol-formaldehyde resin, an aminoplast or the reaction product of an amine with an aldehyde or ketone, and optionally (3) other polymers such as natural and synthetic rubbers, polystyrene, polyvinyl chloride or polymethacrylates. The adhesive is applied to the fibres either in the form of a solution in an organic solvent or as an aqueous latex and then cured by heating.