GB653921A - Improvements in or relating to adhesive coated fabrics - Google Patents

Abstract

An adhesive coated fabric comprises a fabric backing having a normally tacky and pressure-sensitive adhesive coating, including an elastomer, on one side thereof, and a coating of an elastomer that is incompatible with the first-mentioned elastomer, on the other. Incompatibility may be determined by spreading a transparent film of the intimately-blended materials on an inert transparent surface, when they should appear relatively cloudy or tend to separate visibly. The backing may comprise a loosely woven fabric such as gauze, print cloth or elasticized cloth, or non-woven materials in which cotton, wool, or other fibres are sealed to each other crosswise at intervals. The tacky coating may be applied as a solution or as an aqueous dispersion, or by hot-melt spreading, and may comprise any conventionally-used oil-soluble elastomer, such as rubber, reclaimed rubber, butadiene-styrene copolymers, polychloroprene, cyclized or other heat-treated rubber, or polyisobutylene, including polyisobutylene which has been partially unsaturated by copolymerization with a hydrocarbon having two double bonds. Tackifiers such as coumarone-indene resins, rosin or its derivatives, including hydrogenated rosin, dehydrogenated rosin and esters of rosin or these other rosin derivatives, polyterpenes, heat-reactive oil-soluble phenolaldehyde resins or any other type of compatible resins, plasticizers, such as soft or liquid low-melting rosin derivative esters, mineral oils, dibutyl phthalate, tricresyl phosphate, butyl acetyl ricinoleate, butyl levulinate, tributoxy ethyl phosphate, or waxes such as beeswax, paraffin wax, microcrystalline wax or synthetic wax, and inert fillers, may be included. The incompatible coating may consist of an oil-insoluble interpolymer of butadiene with acrylic compounds having no additional aliphatic substitution, or having merely substitution by a short alkyl group, such as interpolymers of butadiene with acrylonitrile, methacrylonitrile, methyl acrylate, methyl methacrylate, ethyl acrylate or other compounds in which the acrylic group comprises a large proportion by weight of the molecule. Polysulphide elastomers may also be used. In examples: (1) a non-woven fabric having cotton fibres united to each other at intervals by polyvinyl chloride acetate copolymer sealing coats is kiss-coated with an aqueous dispersion of a highly polymerized polymer comprising seventy per cent butadiene and thirty per cent methyl acrylate. It is then dried and coated, using a reverse roll coater, with a highly-gelled solution containing natural rubber, hydrogenated rosin glyceride, pure wool fat, and zinc oxide; (2) a loosely-woven cotton fabric is shrunk and then coated on one side with an aqueous dispersion of a highly polymerized interpolymer comprising sixty per cent butadiene and forty per cent acrylonitrile, dried, and coated on the other side with a mixture of polyisobutylene (molecular weight 100,000), factice, liquid polyisobutylene (molecular weight 3,000), polyterpene and aluminium hydrate; (3) a loosely-woven thinly-threaded gauze fabric is coated with a toluene solution of a highly-polymerized copolymer of seventy per cent butadiene, fifteen per cent methyl acrylate and fifteen per cent acrylonitrile, and an adhesive comprising a mixture of a copolymer of approximately 75 parts of butadiene to 25 parts of styrene, having a Mooney value of approximately 55, with polyisobutylene of molecular weight approximately 100,000, liquid polyisobutylene of molecular weight 3,000, mineral oil, polyterpene resin and zinc oxide. Specification 388,556 is referred to.ALSO:An adhesive coated fabric comprises a fabric backing having a normally tacky and pressure-sensitive adhesive coating, including an elastomer, on one side thereof, and a coating of an elastomer that is incompatible with the first-mentioned elastomer, on the other. Incompatibility may be determined by spreading a transparent film of the intimately blended materials on an inert transparent surface, when they should appear relatively cloudy or tend to separate visibly. The backing may comprise a loosely woven fabric such as gauze, print cloth or elasticized cloth, or non-woven materials in which cotton, wool or other fibres are sealed to each other crosswise at intervals. The tacky coating may be applied as a solution or as an aqueous dispersion, or by hot-melt spreading, and may comprise any conventionally-used oil-soluble elastomer, such as rubber, reclaimed rubber, butadiene-styrene copolymers, polychloroprene, cyclized or other heat-treated rubber, or polyisobutylene, including polyisobutylene which has been partially unsaturated by copolymerization with a hydrocarbon having two double bonds. Tackifiers such as coumarone-indene resins, rosin or its derivatives, including hydrogenated rosin, dehydrogenated rosin and esters of rosin or these other rosin derivatives, polyterpenes, heat-reactive oil-soluble phenolaldehyde resins or any other type of compatible resins, plasticizers, such as soft or liquid low-melting rosin derivative esters, mineral oils, dibutylphthalate, tricresyl phosphate, butyl acetyl ricinoleate, butyl levulinate, tributoxy ethyl phosphate, or waxes such as beeswax, paraffin wax, microcrystalline wax or synthetic wax, and inert fillers, may be included. The incompatible coating may consist of an oil-insoluble interpolymer of butadiene with acrylic compounds having no additional aliphatic substitution, or having merely substitution by a short alkyl group, such as interpolymers of butadiene with acrylonitrile, methacrylonitrile, methyl acrylate, methyl methacrylate, ethyl acrylate or other compounds in which the acrylic group comprises a large proportion by weight of the molecule. Polysulphide elastomers may also be p used. In examples: (1) a non-woven fabric having cotton fibres united to each other at intervals by polyvinyl chloride acetate copolymer sealing coats is kiss-coated with an aqueous dispersion of a highly polymerized polymer comprising 70 per cent butadiene and 30 per cent methyl acrylate. It is then dried and coated, using a reverse roll coater, with a highly gelled solution containing natural rubber, hydrogenated rosin glyceride, pure wool fat, and zinc oxide; (2) a loosely woven cotton fabric is shrunk and then coated on one side with an aqueous dispersion of a highly polymerized interpolymer comprising 60 per cent butadiene and 40 per cent acrylonitrile, dried, and coated on the other side with a mixture of polyisobutylene (molecular weight 100,000), factice, liquid polyisobutylene (molecular weight (3,000), polyterpene and aluminium hydrate; (3) a loosely woven thinly-threaded gauze fabric is coated with a toluene solution of a highly polymerized copolymer of 70 per cent butadiene, 15 per cent methyl acrylate and 15 per cent acylonitrile, and an adhesive comprising a mixture of a copolymer of approximately 75 parts of butadiene to 25 parts of styrene, having a Mooney value of approximately 55, with polyisobutylene of molecular weight approximately 100,000, liquid polyisobutylene of molecular weight 3,000, mineral oil, polyterpene resin and zinc oxide. Specification 388,556, [Group IV], is referred to.