Showing papers on "Nitrile rubber published in 1975"

Ground Rice-Hull Ash as a Filler for Rubber

Abstract: A ground rice hull ash prepared by a new burning process has been found to be a moderately reinforcing filler for rubber. This filler, 85-90% amorphous silica and 10-15% carbon, is made by a controlled incineration process in which the bulk of the organic components of the rice hulls is removed, leaving the skeletal silica structure of the hull intact and in the amorphous state. The resultant ash is easily ground to produce fine particles, generally in the range of 0.1-2.0 μm. This filler does not adversely affect either the vulcanization characteristics or the aging of SBR, natural rubber, nitrile rubber, butyl rubber, neoprene, EPDM, and propylene oxide rubber compounds. As it is predominantly silica, it responds effectively to silane coupling agents in improving properties of the rubber compounds. It is concluded that RHA filler is a satisfactory substitute for MT black and that, in blends with blacks, it can be effectively used as a partial replacement for finer and more reinforcing blacks.

Fluid control valve

Abstract: The present invention provides an improvement in fluid flow control valves which utilize polymeric rubbery materials either as the valve member or the valve seat in the flow control valve. The improvements are obtained by utilizing as the rubbery material for either the valve seat or the valve, a semi-rigid to rigid rubbery material prepared by curing a nitrile rubber with from three to 15 parts of sulfur per 100 parts of rubber. Such cured rubbers when utilized in said application, have been found to overcome the problems exhibited by the rubbery materials heretofore used for such applications.

Heat transfer composition and method of making

Abstract: A heat transfer composition, consisting essentially of an epoxy resin, a high temperature curing agent therefor, nitrile rubber, polybutene, particulate heat transfer coefficient-increasing filler and a cold flow control agent such as asbestos.

Vulcanizable compositions of a halogen-containing polymer and a diene-nitrile rubber having active halogen cure sites

Abstract: Compositions comprised of a polymer blend of a halogen-containing polymer and a diene/nitrile rubber having active halogen cure sites are covulcanized using a common cure system The halogen-containing polymers used in the polymer blend include the commercial polymers such as epihalohydrin polymers, polychloroprenes, fluoroelastomers, halogen-containing acrylates, and halogenated polyolefins The curative ingredients employed are those normally used for the cure of the halogen-containing polymer employed in the polymer blend

Adhesive resin composition

Abstract: An adhesive composition comprised of a nitrile rubber having carboxyl groups and a polyamide resin derived from polymeric fatty acids and alkylene polyamines. Such adhesive compositions are useful upon sheet members of plasticized polyvinylchloride, among other possible uses.

Anisotropy in Molded Nitrile Rubber

Abstract: Measurements of linear swelling in solvent of small test pieces provide a useful means of investigating anisotropy in vulcanized products and components whose small size precludes the use of conventional tests on dumbbells, etc. Anisotropy has been found to be present in molded components. The extent of this is related to the material flow in the mold before or during vulcanization. There also appears to be an effect of flow on crosslink density. In this preliminary investigation the contribution of each of the various factors, e.g., filler- filler structure, polymer gel, polymer-filler interaction, tendency to prevulcanize, has not been established.