Showing papers on "Nitrile rubber published in 1980"

Scanning Electron Microscopy Studies of Nitrile Rubber Fractured Surfaces

Abstract: The fracture surfaces of a NBR vulcanizate after different test conditions have been studied by scanning electron microscopy. It has been shown that failure surfaces manifest typical characteristics dependent on the nature of the test. Tensile fracture surface shows occurrence of two different tear rates in the case of a filled NBR vulcanizate, while tear fracture is characterized by a few long flow lines. De Mattia flexing leads to layering of polymer fibers. Heat buildup and abrasion tests generate a ribbed structure on the surface.

Ethylene-vinyl acetate copolymer rubbers

Abstract: The Mooney viscosity and green strength of ethylene-vinyl acetate (EVA) copolymer gum stock is improved by the addition thereto of a suitable elastomer such as: high viscosity ethylene propylene rubber (EPR); nitrile rubber; polychloroprene; polyacrylate rubber; polyurethane; chlorinated polyethylene; polyester; ethylene-propylene diene monomer (EPDM) terpolymer; and other elastomers such as ethylene-methyl acrylate, ethylene butyl acrylate and acrylonitrile types.

Electric cable for medium voltage

Abstract: This invention refers to a medium voltage electric cable (up to about 45 kV) comprising one or more cores, each of said cores being constituted by a conductor covered with an inner semiconductive screen, an insulation layer of extruded polymeric material (preferably, cross-linked polyethylene or ethylenepropylene rubber) and an outer semiconductive screen. The outer semiconductive screen, which is extruded on the insulation and vulcanized at the same time as the insulation in a continuous vulcanizing line, is constituted by a mixture based on a blend of nitrile rubber and ethylene-propylene rubber and containing carbon black, cross-linking agents and various additives. The blend of nitrile rubber and ethylene-propylene rubber comprises 50-70 parts by weight of nitrile rubber and 50-30 parts by weight of ethylene-propylene rubber. The so constituted outer semiconductive screen has good adhesion to the insulation and can be easily removed from said insulation.

Ethylene loss from the gas phase of container‐seal systems

Abstract: Ethylene losses from the gas phase of various container-seal systems were studied to develop acceptable methods for containing ethylene during experiments. Ethylene at an initial amount of 104 μI I-1 was stored in glass vials at near atmospheric pressure for 20 h at 25–27°C and at 35% relative humidity external to the vials. Crimped serum vials sealed with saturated (NH4)2SO4 solution, neoprene rubber septa, nitrile rubber (Hycar) septa, butyl rubber septa, and brown translucent silicone rubber septa lost ethylene at the rate of 1.8, 10.2, 16.2, 16.5, and 40.2 nl m-2s-1, respectively, over the 20-h period. Screw-capped reaction vials sealed with white silicone rubber septa lost ethylene at the rate of 30.2 nl m-2s-1. The (NH4)2SO4 solution was utilized as a seal by inverting a vial so that the salt solution covered the internal surface of the vial septum. Saturated (NH4)2SO4 solution is an effective seal. Silicone rubber should be avoided as a seal in systems for containing ethylene. Ethylene production values in the literature may be underestimates where silicone rubber seals have been used.

Method of fabricating an eraser

Abstract: A method of fabricating an eraser which contains a main basic material of low crystallizable polyolefin thermoplastic elastomer and normal synthetic rubbers having no hard segment for performing a crosslinking effect, namely, any one or more of chlorinated polyethylene, ethylene-propylene terpolymer, ethylene ethyl acrylate, ethylene-vinyl acetate copolymer, atactic polypropylene, styrene-butadiene rubber, nitrile rubber and the like. The thermoplastic elastomer exhibits similar properties to vulcanized rubber without particular vulcanizing operation and crosslinking reaction. In case that less than 40 parts by weight of the elastomer is contained in the eraser, the composition does not form an eraser, while in case that higher than 100 parts by weight of the elastomer is contained in the eraser, the composition incorporates excessive rubber-like properties. The method comprises the steps of mixing and kneading 50 to 800 parts by weight of factice, 0 to 500 parts by weight of filler and predetermined amount of pigment which 40 to 100 parts by weight of the low crystallizable polyolefin thermoplastic elastomer. Thus, the eraser is remarkably improved in the properties such as resistances to deterioration by aging, exposure to sunlight, migration of plasticizer, and tearing strength by its metallic band.

Effect of Curing Temperature on the Technical Properties of Nitrile Rubber and Carboxylated Nitrile Rubber

Abstract: In a mixed crosslink system (sulfur and metal carboxylate) of XNBR vulcanizate, the variations of the proportions of curatives (low sulfur/high accelerator or high sulfur/low accelerator) have little effect on the vulcanizate properties. But aging studies indicate that the metal ion crosslinks are modified in the presence of a sulfur vulcanizing system. NBR vulcanizates with a comparable recipe have less crosslink density than the corresponding XNBR ones. In general, the technical properties and aging resistance of mixed crosslink systems using ZnO2 and sulfur donor-sulfur are better than the NBR vulcanizates. Increase of curing temperature does not always lower the technical properties of XNBR and NBR vulcanizates. Addition of XNBR to NBR in XNBR-NBR blends lowers most of the technical properties, possibly due to different vulcanization characteristics.

Resistance of nbr-based fuel hose tube to fuel-alcohol blends

Abstract: The recent history of nitrile rubber (NBR) fuel hose tubes is reviewed, with special emphasis on retention of physical properties after exposure to various test media, including fuel-alcohol blends. Also studied was the problem of permeability. It was found that one route to dramatically lowering permeabilities is the application of a thin veneer of nylon to an NBR base.

Flexible fuel tank of coated aromatic polyamide fabric - has high shock resistance but low deformation under steady load

Abstract: A container, esp. a fuel tank for a vehicle, has a flexible wall and is made of a high-strength fabric of aromatic polyamide conventionally coated on one or both faces with an elastomer, a synthetic resin or another plastics material. Pref. a polyamide fabric in several layers is used and the coating material is a natural rubber, nitrile rubber or chloroprene rubber. A tank made in this way is sufficiently flexible to withstand bombardment from small projectiles and other shocks and impacts but nevertheless is not excessively flexible to distort. A typical polyamide fabric is nylon 66. By using an aramide fabric a three times greater energy absorption is obtd. as compared with that for conventional polyamide fibres.

Sheet gasket material contains synthetic fibres - and carboxylated nitrile rubber binder

Abstract: Content of carboxylated NBR is >=5% dry wt. The synthetic fibres consist of glass, silicate, quartz, ZnO2, TiO2, boron carbide, metal or carbon, pref. Al silicate for low cost or Al2O3 for high performance. Length of fibres is 1-20 mm. The material may be reinforced with metal gauze or sheet. Prepn. is by mixing the fibres with rubber soln. or latex to a pasty consistency and converting to sheet or a calender or paper-making machine. Use of asbestos fibres with associated health hazards is avoided, while retaining the heat resistance.

Latex bound non-asbestos paper

Abstract: Non-asbestos paper alternatives to latex-bound asbestos papers comprise vitreous fibres derived from wool-form material, organic web-forming fibres, unfired ball clay and water-insoluble non-fibrous particulate inorganic filler, the whole being bound together by a cured nitrile rubber; said paper being made by dewatering as a layer on a water-permeable conveyor an aqueous slurry whose solids content comprises by weight vitreous wool-form material 20-40%, organic web-forming fibres 5-15%, ball clay 5-20%, nitrile rubber 10-20%, and inorganic non-fibrous filler 5-50%, and compressing and drying the layer of dewatered slurry.

Material for forming inner tube of rubber hose for fuel

Abstract: PURPOSE:To provide the title material having excellent resistance to gasoline, and desirable compression-set characteristics, suitable for the use in an engine room, and composed of a mixed polymer obtained by compounding an acrylonitrile rubber with a specific amount of polyvinyl chloride. CONSTITUTION:A nitrile rubber is blended with 30-70wt% of polyvinyl chloride e.g. in a closed mixer at a high temperature. The polymer blend is compounded with other additives such as zinc oxide, stearic acid, sulphur, etc. to obtain the objective material. The amount of the polyvinyl chloride determines the cold resistance and the elongation of the material exposed to sour gasoline.

Production of liquid crystal cell

Abstract: PURPOSE:To obtain the liquid crystal cell of high grade inexpensively by using solvent type adhesive agents of silicone rubber base and nitrile rubber base for the adhesive agents which seal the liquid crystal cell in the liquid crystal cell which does not have any liquid crystal injection port. CONSTITUTION:One kind of solvent type adhesive agnets of silicone rubber base, nitrile rubber base, chloroprene rubber base and polyester resin base is beforehand coated to the specified pattern on a segment electrode substrate 21 or common electrode substrate 22 by a gravure offset printing machine, after which it is predried. For example, a solvent type adhesive agent 32 is transferred on the substrate 31 at the specified pattern by way of a blanket 35. Thence, a required amount of liquid crystal is dropped on either of the substrates and the other substrate is superposed thereon, thence they are bonded to the specified thickness by a hot press under controlled temperature 42 and pressure 45.

Production of rubber hose

Abstract: PURPOSE:To produce a rubber hose with a dimensional stability excellent in the inter-layer adhesivity by applying a reinforced layer on the circumference having convex lines on the inner rubber layer, as coated with an unvulcanized rubber sheet layer after an adhesive is applied on the surface of the layer previously vulcanized CONSTITUTION:A nitrile rubber composition is extrusion molded like a tube and an inner rubber layer 1 composed of an unvulcanized rubber tube having a plurality of convex lines extending lengthwise on the entire circumference thereof The rubber tube is vulcanized in the steam The circumference is coated with an adhesive, on which an unvulcanized rubber sheet composed of a nitrile rubber and styrene butadiene rubber rolled Thus, an unvulcanized rubber sheet layer 2 is formed The layer 2 is superlaid with a vinylon filament-braided reinforced layer 3 having the styrence butadiene rubber dipped The product is passed through an extruder to form an outer rubber layer 4 unvulcanized comprising a chloroprene rubber With a lead skin applied on the circumference of the hose, it is vulcanized with water sealed therein so that the steam pressure is applied thereon from the inside in the pressurized steam

Toughening of Anhydride Cured Epoxy Resins

Abstract: : Anhydride cured DGEBA epoxy resins are toughened against crack propagation by incorporating functionally terminated liquid butadiene-acrylonitrile rubber (CTBN). Spherical domains of 2 - 3 micrometers diameter are formed in situ during cure. With increasing amounts of rubber, the size of the second phase particles decreases. Thermo-mechanical and dielectric properties of the modified resins deteriorate rapidly beyond 10% rubber content. The temperature, T sub g of the unmodified system is 129 deg C; it drops to 126 deg with 10 parts rubber and to 119 deg C with 20 parts. The excess rubber appears to copolymerize with the matrix resin. Also the coefficient of thermal expansion increases disproportionately. The appearance and growth of secondary relaxation peaks in the dielectric spectra due to nitrile groups may be associated with the plasticizing effect of the excessive rubber. Epoxy filled with liquid rubber-treated silica powder shows a twofold improvement in fracture surface work compared to untreated filler. An interaction of the secondary amino groups of the ATBN (amine terminated) rubber with the epoxy-silane coupling agent on the silica and the epoxy resin appears to take place.

Permeation of protective garment material by liquid halogenated ethanes and a polychlorinated biphenyl

Abstract: The halogenated ethanes 1,2-dichloroethane; 1,1,1-trichlorethane; and 1,1,2-trichlorethane are used as chemical intermediates and in metal working operations, and polychlorinated biphenyls (PCBs) have in the past been used by the tens of millions of pounds in various roles in American industry. Because of the widespread use and hazardous or potentially carcinogenic nature of these compounds, a study was performed to determine the degree of protection which was afforded against these compounds by certain protective garment materials. The materials evaluated in these studies have included: butyl rubber, milled nitrile rubber, neoprene rubber latex, nitrile rubber latex, polyethylene, poly(vinyl alcohol), surgical rubber latex, Teflon, and Viton as well as the following composite or multilayered materials: butyl-coated nylon, polyethylene-coated Tyvek, polyurethane-coated nylon, and poly(vinyl chloride)-coated nylon. The breakthrough time at which each liquid phase compound permeated these materials was studied by the time lag method. For the noncomposite materials, the results of these breakthrough studies were correlated with their equilibrium weight changes following immersion in the test liquids. Results of these studies have shown that most materials currently used in the construction of protective garment material in the United States are of a generally unsatisfactory nature with respect to protecting the worker against themore » halogenated ethanes and the PCB used in this study.« less

Drying device in wet development system

Abstract: PURPOSE:To provide the device which does not cause decrease in effect despite low temperature even during continuous passing of paper and has sufficient drying capacity by constituting the driven side roller out of pair of the rollers of the drying device after developing device with silicone rubber CONSTITUTION:Driven side nitrile rubber rollers 4, 6, driving metal rollers 5, 7, 8, 11, a plotter roller 9 and a silicone rubber roller 10 are disposed The silicone rubber roller 10 is pressed onto the metal roller 11 surface by the pressing spring 12 provided to a roller revolving bearing 13 Developing solution L is supplied from slight 15a to recording paper 3 and returns from a recovery vessel 19 into a solution storage tank 16 The developing solution deposited on the recording paper 3 is squeezed at a certain degree by the nitrile rubber roller 6 and is further absorbed by the plotter roller 9 Further, it receives squeezing action and liquid absorbing action by the silicone rubber roller 10, thus the deposited developing solution is perfectly removed and the recording paper comes out in a dry state

Preparation of magnetic coating material

Abstract: PURPOSE:To obtain a magnetic coating material for magnetic tapes, having improved maximum magnetic flux density, by mixing and dispersing a magnetic material only in part of a binder, and by adding the remaining binder to the mixture. CONSTITUTION:A magnetic material, e.g. Co-containing iron oxide, is mixed and dispersed in part, preferably 1/10 or more of the total amount, of a binder, e.g. vinyl alchol-containing vinyl chloride-vinyl acetate copolymer, nitrile rubber, and a polyurethane elastomer, and if necessary an additive, e.g. soybean lecithin, in a sand mill. The remaining binder is added to the mixture and kneaded throughly. A hardener, e.g. an isocyanate compound, is then added to give a magnetic coating material.

About the influence of hexamethylene tetramine content on the dynamic-mechanical properties of the polymeric system: Phenolic novolac resin (PF) and nitrile rubber (NBR-29)

Abstract: On mixtures of phenolic novolac resin (PF) and nitrile rubber with 29% ACN-content (NBR-29) the effect of hexamethylene tetramine content was investigated by torsional pendulum measurements. The shear modulusG′ and the loss modulusG″ were registered within a temperature region from −180°C up to 200°C for different hexa-contents.

Ink roller for dry lithographic printing

Abstract: PURPOSE:To prevent non-picture parts from being stained in dry lithographic printing, by specifying rubber hardness for an ink roller. CONSTITUTION:A material of rubber hardness more than 50 is used for an ink roller in contact with a printing plate. Natural rubber, nitrile rubber, butyl rubber, etc. are suitable for use. But, if their rubber hardness is above 50, epoxy and polyacetal resin, stainless steel and copper may be used.

Aqueous epoxy resin paint

Abstract: PURPOSE:To provide title paint having improved adhesion properties of film, consisting of principal agent composed of liquid epoxy resin and nitrile rubber- modified epoxy resin and a hardener obtd. by adding a specified latex to a polyamide emulsion-type hardener. CONSTITUTION:Principal agent is prepared by adding (B) 5-20pts.wt. (based on 100pts.wt. of non-volatile matter of liquid epoxy resin) of nitrile rubber-modified epoxy resin to the liquid epoxy resin. A hardener is prepared by adding (D) (a) styrene-butadiene resin latex or (b) styrene-butadiene-methyl methacrylate resin latex to (C) a polyamide emulsion-type hardener in an amount of 50-200pts.wt. of said latex per 100pts.wt. of non-volatile matter of said emulsion-type hardener. The principal agent is mixed with the hardener in an specified amount to obtain aq. epoxy resin paint having improved adhesion properties of film.

Elastomers containing chemically bonded metal atoms

Abstract: An elastomer containing chemically bonded metal atoms is prepared by reacting a diene elastomer such as a nitrile rubber with the reaction product of an epoxy resin and a metal containing polymer. The metal containing polymer is prepared by reacting a polycarboxylic acid and a metal complex which is a reaction product of tungsten carbonyl and/or molybdenum carbonyl with pyrrolidine.

Precrosslinked nitrile rubber polymer blends with linear polymers

Abstract: Precrosslinked nitrile rubber polymers are prepared by interpolymerizing a polyol polyacrylate with butadiene and acrylonitrile to improve compression set, extrusion rate and die swell properties of the precrosslinked polymers and blends thereof with linear nitrile rubber polymers without sacrificing other physical and processing properties.

Preparation of radiationnresistant resin composition molded article

Abstract: PURPOSE:To obtain a resin molded article with improved radiation resistance by a method wherein acenaphthylene is compounded to a thermoplastic resin or rubber containing a free-radical generating agent and polymerized by heat molding. CONSTITUTION:To 100pts.wt. of a thermoplastic resin or rubber mixed with a free-radical generating agent, acenaphthylene shown by the formula (where R is 1-4C alkyl; X is 0-4) or a derivative thereof is compounded in a ratio of above 0.5pts.wt. and polymerized within a resin or rubber by heat molding. As resin materials of which radiation resistance must be improved, polyethylene, polybutene, ethylene-vinyl acetate copolymer, polyester, nitrile rubber, silicone rubber or the like are mentioned. As derivatives of acenaphthylene shown by the formula, 5,6- dimethylacenaphthylene, 3,5,6,8-tetramethylacenaphthylene, 3,5-dipropylacenaphthylene or the like are mentioned.

Production of coated phenol molding

Abstract: PURPOSE:To produce the coated phenol molding having woodlike feel without degrading moldability by compounding nitrile rubber as a phenolic resin molding material and increasing the amount of compounding of woodmeal. CONSTITUTION:The molding material of the phenolic resin comprises 50-70% of wood-base material such as woodmeal or the like, 5-10% of nitrile rubber, 0.3- 0.6% of release agent and the rest of phenolic resin. The molding is molded from the material of this formation by ordinary methods. Then, the compounding of nitrile rubber enables the fluidity of the phenolic resin molding material to be improved, and the amount of compounding of woodmeal to be increased, thus the molding of superior hardness, tactile impression, striking sound, etc. may be obtained. After this, this molding is subjected to painting such as Japanese lacquer coating, urethane coating, etc. like this molding.

Nitrile rubber composition for seal

Abstract: PURPOSE:Titled composition which provides sealing materials having excellent sealability, prepared by adding to a nitrile rubber polymer, specific carbon black and fine powder of a parallel cleaving mineral. CONSTITUTION:(A) 100pts.wt. of a nitrile rubber polymer is mixed with (B) 30-50pts.wt. of carbon black, with average particle diameter >=200mmu, oil absorption =2,000mmu, and surface area (N2 adsorption) /g. A sealing material produced by molding the resulting composition after vulcanization, and then lip-cutting the molded product, can seal effectively even for a shaft having a surface roughness of 7s, a feed pitch of 0.7-0.8mm. and a lead angle of 1 deg., which causes fluid leakage by the seal of the prior art when the direction of rotation coincides with the direction in which the shaft demonstrates the function of transportation of the fluid.

PVC film laminate with low petrol permeability - comprises PVC, plasticiser mixt., carbon black and elastomer e.g. EVA or nitrile rubber

Abstract: PVC film laminate resistant to hydrocarbons and with a petrol permeability of 2g/m2/day and a surface resistance of 106 ohm comprises >=1 PVC film prepd. from 100 pt. wt. PVC, 20-45 pts. wt. mixt. of prim. and polymeric plasticiser; 5-15 pt. wt. carbon black with specific surface of 650-1000 m2/g; 5-15 pts. wt. elastomer e.g. EVA or nitrile rubber. Material can be used as a covering material for fuel containers including petrol and aviation fuels. The film has good surface conductivity and a strength of 12-18 MPa and a weld seal strength of 60% of the material strength despite the addition of the carbon blades.

Manufacturing method of hard elastic grindstone

Abstract: PURPOSE:To obtain a grindstone, durable for external shock and drop shock, with an appropriate elasticity and wear resistance, by jointly using synthetic rubbers of excellent wear resistance and thermohardening resin as an abrasive binder, and making into semi-ebonite system. CONSTITUTION:As a binder for the abrasive grain, a synthetic rubber or nitrile rubber or butadiene-high styrene rubber of excellent wear resistance and an admixture, with 5-10PHR of sulfur included in thermohardening phenol resin, are charged into a metal mold, and vulcanized forming, to obtain a hard grindstone durable for the shock of exterior and drop motion, with an appropriate elasticity and wear resistance provided.

Nitrile rubber composition for shaft sealing

Abstract: PURPOSE:Titled composition having excellent lubricating properties and oil resistance, prepared by vulcanizing and molding a composition prepared by mixing a nitrile rubber polymer, carbon black, fine powder of a parallel cleaving mineral and fine powder of cellulose, and then impregnating the molded product with aliphatic and aromatic lubricating oil. CONSTITUTION:A nitrile rubber composition is obtained by mixing (A) 100pts.wt. of a nitrile rubber polymer with (B) 30-50pts.wt. of carbon black, (C) 30- 50pts.wt. of fine powder of a parallel cleaving mineral and (D) 5-30pts.wt. of cellulose fine powder. Then, this composition is vulcanized, molded and immersed in aliphatic and aromatic lubricating oil heated to 100-150 deg.C to impregnate the fine cellulose powder with the lubricating oil. Thereby, it is made possible to give satis factory lubricity to the lip part without impairing the sealability of sealing fluid.

Nitrile rubber containing cadmium antioxidants

Abstract: Handling problems of cadmium curing agents are minimized by adding to a nitrile rubber latex an antioxidant in the form of a soluble alkali metal salt to form a modified latex and then coagulating the modified latex with a cadmium salt to form nitrile rubber containing bound antioxidant in the form of a cadmium compound. Alternately, a concentrate containing a large proportion of the antioxidant in the form of a cadmium compound is prepared which can be subsequently added to a nitrile latex to provide the cadmate cure function.

Production of plastic film of the composite structure

Abstract: PURPOSE:To obtain a composite material wherein a conductive film is firmly bonded to a plastic film, by plating a thin film consisting of a nitrile rubber and an oil-soluble phenolic resin formed on the plastic film. CONSTITUTION:One or both sides of a plastic film, e.g. polyimide, are coated with a varnish prepared by dissolving a composition of a nitrile rubber with an acrylonitrile content >=51% and an oil-soluble phenolic resin in a mixture of two or three types of solvents, e.g. methyl ethyl ketone, cyclohexanone, and toluene, and cured to form a thin film. The film is then subjected to chemical or electro-plating to form a conductive film consisting of a plating thereon.