Patent GB-1144635-A (GB)
Title: Method of bonding
Inventor: OSBORNE ALAN PAUL
IPC: C08J5/04
Filed: 1965-12-07
Abstract: 1,144,635. Coated textile material. DUNLOP CO. Ltd. 24 Nov., 1966 [7 Dec., 1965], No. 51743/65. Heading B2E. [Also in Division D1] A textile material is bonded to an elastomeric composition which comprises an elastomeric block copolymer having the general formula A-(B-A) n  in which A represents a non-elastomeric polymer block having a second order transition temperature greater than 25‹C and having a number average molecular weight in the range 200 to 100,000, and B is an elastomeric polymer block having a number average molecular weight in the range 25,000 to 1,000,000 and a glass transition temperature below 10‹C and wherein n is an integer of from 1 to 10, by applying the composition to the textile material, crosslinking the elastomeric block copolymer at least in the region of the textile material and heating the assembly under pressure to effect formation of the bond. The elastomeric block copolymer may be crosslinked throughout its whole structure. The non-elastomeric polymer block A of the copolymer is present in an amount of from 10 to 50% by wt. of the coplymer and may be formed from a vinyl benzene e.g. styrene or alpha substituted styrene. The elastomeric polymer block B may be formed from a diolefine e.g. isoprene or butadiene. The copolymer block B may be a rubber like copolymer of two or more mono-olefines e.g. ethylene, propylene, with or without a third monomer to confer unsaturation on the block B. A crosslinking agent may be used to crosslink the elastomeric block copolymer either at least in the region of textile material or throughout the whole of the elastomeric block copolymer e.g. sulphur or a sulphur-generating compound; a peroxide, such as dicumyl peroxide, to which may be added a polyallyl compound; or a polyisocyanate. The crosslinking agent may be applied e.g. as a solution or dispersion, to the textile material prior to application of the block copolymer. The sulphur or peroxide may be present in an amount of up to 2% by wt. of the textile material. The crosslinking agent may be applied to the textile material in admixture with an adhesive composition e.g. based on polychloroprene, natural or synthetic rubber latex mixed with phenol or resorcinol formaldehyde; applied as a solution or dispersion to the textile material which has been previously treated with an adhesive composition; or mixed with the elastomeric block copolymer prior to calendering onto the textile material which may have been treated as above. When mixed with the copolymer the crosslinking agent may be sulphur present in amount up to 10% by weight of the copolymer or a peroxide present in amount up to 5% by weight of the copolymer. When mixed with the adhesive composition the crosslinking agent may comprise a dispersion containing sulphur in amount up to 10% by weight of the adhesive solids. Polyisocyanates can be used in an amount up to 40% by wt. of the copolymer composition. Up to 40% by wt. of polyallyl compounds may be used in combination with not more than 10% by wt. of the peroxide. The textile material and block copolymer are brought and then heated e.g. to 120‹C to 180‹C, under pressure to effect the bond. The textile material may be a natural or synthetic textile, or a rayon, polyester or polyamide e.g. nylon, cord.