GB937254A - Bonding rubbers to siliceous surfaces - Google Patents

Abstract

937,254. Laminates. ESSO RESEARCH & ENGINEERING CO. April 11, 1961 [May 19, 1960], No. 12992/61. Class 140. Natural rubber, or a synthetic rubber such as polyisoprene, polybutadiene, a butadiene-styrene or -acrylonitrile copolymer, polychloroprene or a chlorinated or brominated copolymer of isobutylene and isoprene, is bonded to a siliceous surface such as glass sheet, flake, fibrous mat, cord or woven fabric, or ceramic material, by applying to the surface an unsaturated organic silane, applying the rubber and curing with an organic peroxide. Bonding may be further assisted by the use of a polyunsaturated monomer, such as divinyl benzene, which may be added to the rubber, applied, as a separate coating over the silane coating, either as such, as a blend with a minor proportion of a rubber (not necessarily that of the main rubber layer), or applied as a separate film made from such a blend. Part of the peroxide curing agent may be added to the polyunsaturated monomer or blend thereof. The unsaturated silane used is of the formula R n SiX 4-n , where R is an unsaturated hydrocarbon group such as vinyl-, allyl, methallyl-, or styrenyl-, X is halogen, or a hydroxy- or ether-group, and n is 1, 2 or 3. Examples are given. Polyunsaturated monomers used include, beside divinyl benzene, di- or tri-vinyl derivatives of substituted and unsubstituted benzene, naphthalene or phenanthrene, di- or tri-acrylates or methacrylates, esters such as divinyl adipate, triallyl cyanurate, diallyl phthalate or vinyl fumarate, polyvinyl ethers, and divinyl diethoxysilane. The peroxides used include dicumyl peroxide, ditert-butyl peroxide, 2,5-bis (tert-butyl peroxy)- 2,5-dimethyl hexane and benzoyl peroxide. In an Example (I) a glass plate is immersed for 30 minutes in an xylene solution of vinyl trichlorosilane, washed with water and dried, brushed with divinyl benzene, combined with a layer of natural rubber containing dicumyl peroxide, and cured at 300‹ F. under pressure. In other examples, (V) and (VIII), glass fabric is immersed in benzene to which the acid chloride of vinyl tri-(2-methoxy-ethoxy) silane is added dropwise up to 2¢%; the fabric is washed successively with benzene, isopropanol and water, dried with heat and vacuum, and placed between two layers respectively of compounded natural rubber, nitrile rubber and chlorbutyl rubber containing dicumyl peroxide, these layers being uncoated (V), and coated (VIII) with divinyl benzene, ethylene dimethacrylate, trimethylol propane trimethacrylate and triallyl cyanurate respectively, all coatings containing dicumyl peroxide, and heat cured under pressure.