Patent GB-814699-A (GB)
Title: Halogenated butyl rubber compositions
IPC: B29D30/40
Filed: 1957-07-05
Abstract: An aqueous composition comprising 100 parts by weight of a halogenated butyl rubber and from 2 to 60 parts of a phenol-aldehyde resin is used to coat fibrous material.  The butyl rubber copolymer comprises 85 to 99.5 weight per cent of an iso-olefine of 4 to 8 carbon atoms, e.g. isobutylene and 0.5 to 15 weight per cent of a multiolefine of 4 to 10 carbon atoms, e.g. butadiene, dimethyl butadiene, piperylene or isoprene and the halogen content is 0.5 weight per cent of combined halogen and not more than one combined atom of chlorine or three combined atoms of bromine per double bond in the copolymer.  The phenol-aldehyde resins may be derived from compounds such as phenols, cresols, phloroglucinol, xylenol, tri-methyl, mono- or dichlorodiamyl or diisopropyl, p-tert. butyl and p-phenyl phenols, hydroquinone and resorcinol and aldehydes such as formaldehyde paraformaldehyde, acetaldehyde and furfural.  The compositions may be prepared by dissolving the halogenated rubber in a hydrocarbon solvent e.g. hexane, and emulsifying with water containing from between 0.5 and 20 weight per cent of emulsifier, and non-ionic, anionic and cationic types are listed.  The solvent is removed by stripping.  The rubber latex may be mixed with an aqueous solution containing the phenol and aldehyde, and the pH of the mixture adjusted, for example by caustic soda to between 7.5 and 9, and the mixture is then allowed to stand until condensation takes place.  A phenol dialcohol, in an amount of, from 1 to 35 parts by weight may also be added to the dispersion.  Cord, filament or layers of fabric dipped in the composition, dried, and embedded in rubber which is then vulcanized with the usual agents, show improved adhesion to the rubber, and are suitable for use as tyres and reinforced laminated structures such as conveyer belts.ALSO:A fibrous material, e.g. of cotton, rayon, silk or nylon, is coated with an aqueous composition comprising 100 parts by weight of a halogenated butyl rubber and 2-60 parts of a phenol-aldehyde resin, whereby its adhesion to butyl rubber, after vulcanization at from 250-400 DEG F., is improved.  The fibres may be in the form of a cord or a single layer of fabric, which may be coated on one or both sides with the composition.  The butyl rubber copolymer comprises 85-99.5 weight per cent of an isoolefine of 4-8 carbon atoms, e.g. isobutylene, and 0.5-15 weight per cent of a multiolefine of 4-10 carbon atoms, e.g. butadiene, dimethyl butadiene, piperylene or isoprene, and the halogen content is 0.5 weight per cent, not more than one combined atom of chlorine or three combined atoms of bromine being present per double bond in the copolymer.  The phenolaldehyde resins may be derived from compounds such as phenols, cresols, phloroglucinol, xylenol, trimethyl-, mono- or dichloro-, diamyl-, diisopropyl-, p-tert. butyl- and p-phenyl-phenols, hydroquinone and resorcinol, and aldehydes such as formaldehyde, paraformaldehyde, acetaldehyde and furfural.  Emulsifiers, and a phenol dialcohol in an amount of 1-35 parts by weight, may also be present in the dispersion.