Showing papers on "Nitrile rubber published in 1978"

Advances in Nitrile Rubber Technology

Abstract: Considerable advances have been made in NBR technology and still more are possible. The heat resistance of NBR has been raised so that it will with-stand 150°C in air for short periods, instead of 120°C. There is potential in the polymer backbone for still greater stability. It has been demonstrated that the ozone resistance of NBR can be improved by blending with EPDM, but the optimum blend has not yet been developed. The use of PVC to improve the ozone resistance of NBR is now much better understood. Crosslinked NBR has been developed as a non-migratory plasticizer which improves embossing characteristics of PVC and PVC-ABS blends. This, in turn, led to the production of NBR powders which may be used to speed up compounding on conventional equipment and permit rubber to be compounded in equipment generally used for fabricating plastics. Powder black masterbatches of NBR are now being evaluated in industry. Another new product form is liquid NBR, generally with reactive end groups. This is alrea...

Process for preparing epoxy laminates for additive plating

Abstract: A process for preparing an epoxy impregnated laminate having an adhesive surface conductive to electroless plating wherein the adhesive surface is applied from a transfer sheet as a substantially uncured phenolic thermosetting resin/nitrile rubber polymer adhesive layer which is thereafter cured by subjecting the laminate to heat and pressure curing conditions.

Heat-sensitive adhesive composition

Abstract: PURPOSE:To obtain the title composition excellent in antiblocking property, low-temperature adhesive force and weathering resistance, by mixing a nitrile rubber with an epichlorohydrin rubber and a specified tackifier. CONSTITUTION:100 pts.wt. nitrile rubber such as nitrile/butadiene copolymer of an acrylonitrile content of, for example, 15-50wt.% is mixed with 10-200 pts.wt. epichlorohydrin rubber (e.g., epichlorohydrin homopolymer) and 10-200 pts.wt. tackifier such as a phenolic resin, a petroleum resin or a rosin resin.

Paper conveying belt conveyor

Abstract: PURPOSE: To provide the subject belt conveyor for conveying papers between belts wherein a polyester canvas is embedded in nitrile rubber or the like containing a conductive material and, at the same time, exposed partly, thereby preventing occurrence of flexible phenomena at portions of changing the conveying direction. CONSTITUTION: As a core material 9 of an endless belt 8, there is used a polyester canvas fabricated by intertwining vertically and horizontally polyester yarns. As a mother material 10 there is used a nitrile rubber which contains a conductive material such as carbon and the like so that static electricity escapes to a pulley, and further is a copolymer of acrylnitrile having excellent wear resistance and butadiene or a styrene-butadiene rubber which is a copolymer of styrene and butadiene. Further, on the conveying surface 11 there is exposed partially from the mother material 10 a part where the polyester canvas which is the core material 9 is protruded. Further, the pulley comes into contact with a pulley surface 12. COPYRIGHT: (C)1979,JPO&Japio

Halogen-free fire-resistant strong olefin! copolymer mixt. - contains pptd. alumina hydrate having small particle size and given specific surface

Abstract: Flame-resistant halogen-free polymer mixts contain, as basic polymers, (A), olefin copolymers with acrylate esters, C2H4-acrylate rubber, acrylate rubber, or their blends with one another or with other polymers, eg nitrile rubber, polyethylene or olefin copolymers, and, as additive, wrt 100 parts (A), 90-200 (120-180) parts Al2O3 hydrate, (I), having particle size 6 mu, specific surface >6 m2/g and contg, wrt Al2O3, >025 (>04)% Na2O including >=005 (>=010)% soluble Na2O The polymer mixts are used as insulating-, filler- and/or sheathing mixts for electric cables and conduits, and also for the prodn of floor and wall covers and technical articles, eg conveyor belts, seals, coated textiles The mixts are flame-resistant, stable to oil and sea-water, are non-smoking and have good workability The structural surface of (I) has a favourable catalytic activity on (A), crosslinking and age-retarding

Preparation of nitrile rubber

Abstract: PURPOSE:To prepare a nitrile rubber having improved flexibility and crack growth resistance in oil, by polymerizing a part of a monomer mixture in the presence of a large amount of a molecular weight controlling agent, and successively polymerizing on addition of the residual monomer and a small amount of the molecular weight controlling agent.

Epoxy resin composition

Abstract: PURPOSE:To provide an epoxy resin composition having excellent storage stability and strong adhesivity to metal when cured, and giving a cured product with excellent heat resistance and impact strength, composed of an epoxy resin, a nitrile rubber and a phenolic resin.

Cellular construction elements - formed from expanded mineral aggregates bound by modified phenolic novolak resin foam

Abstract: New construction elements consists of 80-100 vol.% of expanded mineral aggregates bound by a foam formed from powdered novolac-type phenolic resin. Cpd. with previous cellular materials prepd. from polystyrene or polymethane resins, the prods. of this are much less combustible while having satisfactory mechanical properties. The foam binding the aggregates is obtd. from a modified novolak resin of m.pt. 50-100 degrees C, a crosslinking agent and solid expansion agent. The mineral aggregate is vermiculite, perlite, glass, clay or shale. The novolak resin is pref. modified with PVA or an ester, polyceprolactone, polyamide, epoxy resin, nitrile rubber, natural resin and wood-distilln. residues.

Line printer character chain lubricating device

Abstract: A low cost line printer character chain lubricating device that provides an accurate amount of lubricant between a line printer character chain and the hard, smooth support surface about which the chain rotates. The lubricating device is located in a depression in the hard, smooth support surface and includes a piece of flexible, abrasion-resistant, microporous nitrile rubber that is impregnated with lubricating oil. The nitrile rubber has a smooth convex arcuate surface for contacting the character chain. A bracket semipermanently mounts the nitrile rubber in the depression in the support surface such that the convex arcuate surface of the nitrile rubber contacts the side of the character chain that normally contacts the hard, smooth support surface as the chain rotates. Depressions in the nitrile rubber beside the arcuate surface serve as charging reservoirs for the lubricating oil. As the line printer character chain rotates and contacts the arcuate surface of the nitrile rubber, the lubricating device provides oil on a need only basis such that an accurate amount of oil is automatically maintained between the chain and the hard, smooth support surface. The size of the micropores in the nitrile rubber, in relation to the lubricating oil used, controls the desired level of lubrication.

Nonelectrolytic plating method onto high polymer material

Abstract: PURPOSE:To obtain a high polymer material having a metal plating with improved adhesive strength, by chemical roughening of the surface of the material with an aqueous solution containing potassium permanganate and a bromate, and by plating the surface with a metal. CONSTITUTION:A high polymer material, e.g. acrylonitrile-butadiene-styrene copolymer or nitrile rubber, is immersed in an aqueous solution containing 5-50 g/l of potassium permanganate and 10g/l or more of a bromate, e.g. NaBrO3 or KBrO3, roughened chemically, and plated with a metal.

High impact* reinforced polyamide resin composition

Abstract: PURPOSE:A reinforced polyamide composition having excellent impact strength at low temperature and low water content, composed of a polyamide resin, and specific amount of a nitrile rubber and inorganic reinforcement.

High impact aliphatic polyamide compsn. - contg. a copolymer of an alkadiene and acrylonitrile

Abstract: High impact polyamide compsns. comprises (1) 99.9-40 wt. % of an aliphatic polyamide and (2) 0.1-60 wt. % copolymer of (a) 99-60 wt. % 4-6C alkadiene and (b) 40-1 wt. % acrylonitrile. Pref. additive (2) is a copolymer of butadiene and/or isoprene and/or pentadiene-1,3 with acrylonitrile, with a mol. wt. of 2000-500000, esp. 20000-250000, and the compsn. contains 97-50 wt. %, esp. 92-70 wt. % of the polyamide and 3-50 wt. %, esp. 8-30 wt. % of the copolymer. The nitrile rubber additives have excellent compatibility with the polyamide component and can be incorporated e.g. in an extruder. The modified prods. have excellent flexibility and impact strength. The prods. are useful for making shoe soles, flexible tubing and technical mouldings.

Tyre with belt reinforcement between carcass and running tread - has polar rubber separating coating vulcanised on belt layer

Abstract: Vehicle tyre with belt-type reinforcement layer between carcass and running tread based on oil-extended rubber compsns., has a separating layer contg. polar rubber elastomers vulcanised onto the belt layer. The separating layer comprises a rubber compsn. of polar elastomers beside moderately polar elastomers e.g. 50-100, pref. 55-85 pbw strongly polar elastomers and 50-10, pref. 45-15 pbw, moderately polar elastomers. Examples for the former are nitrile rubber, halobutyl and/or chloroprene rubber; and the latter are pref. natural rubber and/or SBR. Migration of the oil extender is prevented.

Morphology stabilization of heterogeneous blends

Abstract: MORPHOLOGY STABILIZATION OF HETEROGENEOUS POLYMER BLENDS ABSTRACT OF THE DISCLOSURE A heterogeneous blend of elastomers having a stabilized morphology, as well as the method of making the same, comprises at least two radiation cross-linkable elastomers which form a heterogeneous blend. The radiation cross-linkable elastomer components are selected from the class consisting of conjugated dienes having from 4 to 12 carbon atoms, natural rubber, poly-alkenamers such as polypentenamer, chlorinated polyolefinic elastomers having from 2 to 8 carbon atoms such as chlorinated polyethylene, ethylene-propylene terpolymers, polysiloxanes, nitrile rubber, butadiene-acrylic copolymers, chlorosulfonated polyethylene, butadiene vinyl pyridine co-polymers, substituted phosphazenes, aliphatic polyesters which are substan-tially non-crystalline and have 6 carbon atoms or more in the repeating unit, preferably from 6 to 12 carbon atoms, butyl copolymers containing groups with unsaturation, a butadiene-styrene copolymer and a copolymer, terpoly-mer, etc., made from a conjugated diene having from 4 to 12 carbon atoms and from monomers selected from the class consisting of a vinyl aromatic having from 8 to 15 carbon atoms, acrylonitrile, and olefins having from 2 to 8 carbon atoms. The morphology of the heterogeneous blend is greatly im-proved or fully stabilized by irradiating to a point below to slightly above the gel dose of the blend, that is to a point where the blend has 15 percent and preferably near or less than 5 percent gel. The greatly improved or fully stabilized morphology permits conventional processing steps to be carried out wherein shear is involved such as in milling, extruding, com-pression or injection molding, and the like such that the final morphology of the blend, after processing, is substantially the same as the initial morphology. Examples of specific heterogeneous elastomeric blends include nitrile rubber blended with an EPDM polymer, styrene-butadiene blended with an EPDM polymer, and polybutadiene blended with an EPDM polymer.

Rubber compositions containing zinc trimellitate

Abstract: Rubber compositions comprising zinc trimellitate and a rubber selected from the group consisting of styrene-butadiene rubber (SBR), nitrile rubber, natural rubber, butyl rubber, polybutadiene rubber and isoprene rubber, the said rubber being sulfur-cured with zinc oxide as an activator.

Di:phenylamine and cyclohexanone condensate - used as antioxidant in opt. vulcanised natural and synthetic rubbery elastomer

Abstract: Condensn. prods., (I) of diphenylamine and cyclohexanone are used as anti-oxidant additives to rubbery elastomers, esp. natural or synthetic 1,4-cis-polyisoprene rubber, butadiene-styrene rubber, polybutadiene-, polychloroprene- or nitrile rubber. (I) prevent oxidn. by O2 or air; cause neither discolouration nor stains, and also prevent damage in use, esp. in bending. (I) can be used in both non-vulcanised and vulcanised rubber elastomers. E.g. in vulcanised natural rubber addn. of 1 wt. % (I) an lower tensile strength reduction, on ageing 4 days at 90 degrees C in air, from 83% to 27%.