Compound 574GY Plasticizers can be added to improve the "wet gel strength" of the nitrile rubber. Such a thin latex may be preferred for manufacturing thin rubber articles. Nitrile is a copolymer of butadiene and acrylonitrile. HNBR has also been widely employed in industrial sealing for oil field exploration and processing, as well as rolls for steel and paper mills. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. It is a synthetic one, formed by combining acrylonitrile and butadiene, those monomers in a large stainless steel vat. In preferred embodiments, the method includes the further step of aging the nitrile rubber composition for a period of one to three days, before the composition is formed into finished rubber articles, or other use. 5. Water serves as the reaction medium within the vessel. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). After the form has been dipped in the coagulant solution and into the nitrile latex composition, the form (with latex film coating thereon) is preferably immersed in a wash fluid, preferably water, to remove residual coagulant and other (generally water-soluble) materials from the latex film. XNBR is a terpolymer of butadiene, acrylonitrile, and acrylic acid. The invention also provides an article of manufacture comprising a layer of the cured nitrile rubber composition formed by the above-described method. The sulfur/butyl zimate cure system used in this example is effective at lower pH levels than cure systems with other accelerators. A carboxylated nitrile rubber formulation was prepared as follows using the amounts of the components shown in Table 1. Use of a coagulant can result in a cured rubber having increased strength, e.g., tensile strength. Thus, in one aspect, the invention provides a nitrile rubber material which, when cured, has a 300% modulus less than about 1100 psi (pounds per square inch). It’s a copolymer made up of a combination of acrylonitrile and butadiene molecules. It is expected that modifications may be necessary to produce satisfactory commercial products. The development of modern rubber materials has made possible the manufacture of a wide range of elastomeric articles having varying properties of strength and chemical resistance. The results of the tests are graphically depicted in FIG. Polymerization is allowed to proceed to ~70% conversion before a “shortstop” agent (such as dimethyldithiocarbamate and diethyl hydroxylamine) is added to react with the remaining free radicals. The tanks are heated to 30–40 °C to facilitate the polymerization reaction and to promote branch formation in the polymer. The raw material is typically yellow, although it can also be orange or red tinted, depending on the manufacturer. However, in certain embodiments, a nitrile latex with a lower level of acrylonitrile can be employed. Perbunan N latex KA8250 is preferred. We custom formulate nearly every natural and synthetic polymer type including Fluoroelastomer (FKM), Vamac (AEM), FDA and medical grade compliant Silicone compounds. Other exemplary protective colloids include plant hydrocolloids such as sodium alginate, proteins other than casein, and other water soluble polymers such as polyvinyl alcohol. wherein the sulfur-cured nitrile rubber is substantially free of a metallic oxide as a crosslinking agent. Sulfur crosslinks often result in large improvements in oil and chemical resistance. Must be compatible with rubber and other compounding ingredients. In a preferred embodiment, the pH of the latex is raised to at least about 8.5 by addition of an alkali metal hydroxide. Thus, laboratory or inductrial gloves preferably include a layer of a cured nitrile rubber of the invention having a thickness between about 10 mil and 30 mil, more preferably between about 15 mil and 28 mil Of course, the skilled artisan will appreciate that the cured nitrile rubber layer of such gloves (or other articles) can be thicker than 30 mils, if greater protection is desired. A preferred article of manufacture is a glove. General Description: Most commonly used general purpose o-ring material because of relative low cost, good mechanical properties, and basic resistance to many common lubricants. The resultant nitrile rubber is substantially free of zinc oxide. ;NORTH SAFETY PRODUCTS INC.;NORCROSS SAFETY PRODUCTS L.L.C. HNBR compounds are formulated to meet demanding applications and environments with a wide operational temperature range. In preferred embodiments, nitrile rubber compositions of the invention are substantially free of zinc oxide. Thus, for example, a layer of a cured nitrile rubber of the invention can be adhered to a layer of another material, e.g., a different rubber or plastic, to form a composite article. Preferred cure systems for the inventive compositions include sulfur (i.e., elemental sulfur) and sulfur donors, in combination with at least one accelerator. NBR, Acrylonitrile Butadiene Rubber, Acrylonitrile Butadiene Latex, Buna-N) is a synthetic polymer made of monomers 1,3-butadiene and acrylonitrile. Important Note: These are Starting Point Rubber Compounding Formulations for providing guide lines only and should be confirmed by laboratory trials. The rubber latex composition according to claim 2, wherein the vulcanization accelerator is a mixture comprising (A) at least one compound selected from the dithiocarbamic acid compounds of the formula (1) and the zinc dithiocarbamate compounds of the formula (2), and (B) the thiazole compound at a ratio (A:B) of 9.5:0.5 to 3:7 (weight ratio). The subject nitrile rubber material also exhibited an increase in area (swelling) of less than 1% after 24 hour exposure to hexane at room temperature. The level of each monomer in the polymer and the level of curing affect the levels of strength and the chemical resistance in the finished article. Such equivalents are considered to be within the scope of this invention and are covered by the following claims. The subject material ("Soft Nitrile") provides greater resistance to chemicals than the control material, a commercially available nitrile latex rubber (a 15-mil-thick glove available from North Safety Products, product code LA153G). The chemical resistance of the glove produced as described above, as measured according to ASTM method F739, is graphically depicted in FIG. RELEASE BY SECURED PARTY;ASSIGNOR:CREDIT SUISSE, ADMINISTRATIVE AGENT;REEL/FRAME:020963/0159, Owner name: This rubber is unusual in being resistant to oil, fuel, and other chemicals. One repeating unit found throughout the entire polymer may not exist. One useful class of rubber compounds is the nitrile rubber class, which is widely used to make a variety of articles of manufacture. A method according to claim 1, wherein the at least one accelerator comprises tetramethylthiuram disulfide and mercaptobenzothiazole. The popularity of nitrile is due to its excellent resistance to petroleum products and its ability to be compounded for service over a temperature range of -22°F to 212°F. No zinc oxide was used. latex, to articles, Compositions of homopolymers or copolymers of conjugated diene hydrocarbons, Characterised by the use of rubbers containing carboxyl groups, Use of inorganic or non-macromolecular organic substances as compounding ingredients, Organic ingredients according to more than one of the "one dot" groups of C08K5/01Â -Â C08K5/59, Crosslinking or vulcanising agents; including accelerators, Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical; Compositions of hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Compositions of derivatives of such polymers, Homopolymers or copolymers of unsaturated alcohols, Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids, Compositions of proteins; Compositions of derivatives thereof, ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LIPINSKI, TIMOTHY M.;REEL/FRAME:010212/0310, NORTH SAFETY PRODUCTS INC., SOUTH CAROLINA, CHANGE OF NAME;ASSIGNOR:SIEBE NORTH, INC.;REEL/FRAME:009876/0959, CREDIT SUISSE FIRST BOSTON, AS COLLATERAL AGENT, N, SECURITY AGREEMENT;ASSIGNORS:MORNING PRIDE MANUFACTURING L.L.C. Accordingly, in certain embodiments, butyl zimate is a preferred accelerator. Rubber Compounds. A method according to claim 1, wherein the stabilizing agent is selected from the group consisting of ammonium caseinate, sodium alginate, and polyvinyl alcohol. Claims: What is claimed is: 1. However, ionic crosslinking often increases the stiffness of an article made from the rubber. Sodium 2-ethylhexyl sulfate is preferably present in a range from about 0.01 phr to about 1.0 phr, and more preferably about 0.05 phr. combining a carboxylated nitrile latex with a stabilizing agent. FIG. In preferred embodiments, the cured nitrile rubber is further characterized in that the tensile strength is greater than about 5000 psi. Typical for plasticizers to act a dual purpose ingredients, increase elongation, reduce hardness, improve tack; depending on the amount and type used and the rubber involved The specific pH needed can vary depending on the particular nitrile latex being used, but can be readily determined by the skilled artisan using no more than routine experimentation. Polymerization tanks are heated to 5–15 °C instead of 30–40 °C. The uses of nitrile rubber include disposable non-latex gloves, automotive transmission belts, hoses, O-rings, gaskets, oil seals, V belts, synthetic leather, printer's form rollers, and as cable jacketing; NBR latex can also be used in the preparation of adhesives and as a pigment binder.. A more comfortable nitrile glove that is easier to stretch, i.e. In general, the use of stabilizers in the subject rubber formulations can decrease agglomeration of latex particles, reducing the formation of defects in articles, such as gloves, made from the rubber formulation. The nitrile rubber compositions of the invention are substantially free of zinc oxide, and have good strength and chemical resistance while being softer than many conventional nitrile rubbers. As described above, the use of zinc oxide in carboxylated nitriles is generally associated with stiffening of the cured rubber. The carboxyl groups are present at levels of 10% or less. 10. The three-dimensional cross-linking occurs through the … CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). 9. A protective colloid can prevent the latex from becoming excessively viscous. While any carboxylated nitrile latex can be employed, latexes having high levels of acrylonitrile are preferred due to the increased chemical resistance of such compositions. NORTH SAFETY PRODUCTS INC., RHODE ISLAND, Free format text: The latex film is then removed from the wash bath and dried and cured to produce a rubber article. MORNING PRIDE MANUFACTURING, L.L.C., OHIO, Free format text: In preferred embodiments, the stabilizer is an emulsifier such as linear sodium dodecylbenzene sulfonate. Thus, in certain embodiments, the use of a stabilizer in an amount effective to prevent agglomeration, is preferred. Other stabilizers include sodium 2-ethylhexyl sulfate. These changes, however, often compromise strength, chemical resistance, or both, resulting in articles that are unsuitable for many applications. Carboxylated nitrile latexes can be chemically crosslinked in at least two ways: the butadiene subunits can be covalently crosslinked with sulfur/accelerator systems; and the carboxylated (organic acid) sites can be ionically crosslinked with metal oxides or salts. has lower elastic modulus, can be made using a polymer which contains less acrylonitrile or by crosslinking the polymer to a lesser degree. Such composite articles can, in some embodiments, provide qualities such as increased chemical resistance, puncture resistance, or tensile strength compared to conventional articles. Nitrile compounds are organic compounds having the general chemical formula R-CN while Viton is a brand name of synthetic rubber and fluoropolymer elastomers. The mechanical response of nitrile rubber can be tested in many different ways. Formula of nitrile rubber products containing reclaimed rubber. Except where otherwise noted, data are given for materials in their, Hydrogenated nitrile butadiene rubber (HNBR), Carboxylated nitrile butadiene rubber (XNBR), Ullmann's Encyclopedia of Industrial Chemistry, "Synthetic Rubber - Study: Market, Analysis - Ceresana", "Bayer, Zeon fined 34.2 mln eur for synthetic rubber cartel activity", 10.1002/1439-2054(20011101)286:11<657::AID-MAME657>3.0.CO;2-2, "Ionic elastomers based on carboxylated nitrile rubber (XNBR) and magnesium aluminum layered double hydroxide (Hydrotalcite)", Manufacturing capabilities in Nitrile Rubber, Existing Substances Evaluation: Butadiene, Antitrust: Commission fines synthetic rubber producers € 34.2 million for price fixing cartel, Information & Resource Site on Nitrile Gloves, http://www.klozure.com/ViewSolutionsPage?page=materials, http://www.iisrp.com/WebPolymers/03HNBR-11Dec2001.pdf, Rubber Industry Smallholders Development Authority, https://en.wikipedia.org/w/index.php?title=Nitrile_rubber&oldid=994742700, Chemicals that do not have a ChemSpider ID assigned, Articles containing unverified chemical infoboxes, Articles with unsourced statements from February 2013, Articles with unsourced statements from August 2017, Creative Commons Attribution-ShareAlike License, This page was last edited on 17 December 2020, at 09:05. Nitrile latexes can be carboxylated or noncarboxylated; carboxylated nitrile latexes are preferred. Assigned to NORTH SAFETY PRODUCTS INC., MORNING PRIDE MANUFACTURING, L.L.C., NORCROSS SAFETY PRODUCTS, L.L.C. In a preferred embodiment, the method includes the further step of curing the nitrile rubber composition to form a cured nitrile rubber composition. RT: Chapter19, “Antidegradants,” F. Ignatz-Hoover, p. 453. An object of this invention is to provide soft nitrile rubber formulations which have strength and chemical resistance comparable to conventional stiffer rubber compositions.  Other applications include timing belts, dampers, servo hoses, membranes, and seals.. The invention provides articles of manufacture, including gloves, which are soft, yet strong, and can be economically manufactured. Nitrile rubber is more resistant than natural rubber to oils and acids, and has superior strength, but has inferior flexibility. 2. In preferred embodiments, a protective colloid is present as stabilizer. NBR is used in the automotive and aeronautical industry to make fuel and oil handling hoses, seals, grommets, and self-sealing fuel tanks. Natural rubber An important factor in the properties of NBR is the ratio of acrylonitrile groups to butadiene groups in the polymer backbone, referred to as the ACN content. PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362, Owner name: Under lower temperature conditions, less branching will form on polymers (the amount of branching distinguishes cold NBR from hot NBR). The invention provides nitrile rubber formulations useful for manufacturing articles having good strength and chemical resistance while being softer (i.e., having a lower elastic modulus) than many previously known rubber formulations. The term "divalent metal oxide," as used herein, refers to an oxide of a divalent metal, i.e., a metal in the +2 oxidation state. These two features are high strength and impermeability to certain hydrocarbon solvents and oils. Gloves were made from the nitrile latex prepared in Example 1, supra, by the following procedure. In preferred embodiments, the stabilizing agent is ammonium caseinate. The cured nitrile rubber is also characterized by having a 300% modulus of elasticity in the range of about 400 psi to about 1100 psi, and by having a tensile strength greater than about 5000 psi. A preferred pigment is titanium dioxide, which is useful when a non-transparent article is desired. Compounding techniques allow for HNBR to be used over a broad temperature range, −40 °C to 165 °C, with minimal degradation over long periods of time. In preferred embodiments, the step of adjusting pH includes adding an alkali hydroxide to the nitrile latex. In addition to these ionic crosslinks, traditional sulfur vulcanization is applied. When reclaimed rubber is blended in nitrile rubber products, increasing the amount of reinforcing fillers can improve the tensile strength and hardness of the rubber products. Crosslinking also increases the strength and elasticity of the rubber. The residence time of the form in the latex composition can be selected to obtain a film of a desired thickness on the form. The clean forms were preheated in an oven to a temperature in the range of 170Â° F. to 220Â° F. The forms were then dipped into a coagulant solution of calcium nitrate, followed by dipping into the latex compound described in Example 1. 6. The level of agitation was sufficient to disperse the other ingredients quickly as they were added; optionally, a small amount of defoamer can be added if necessary. However, in other preferred embodiments, e.g., if a substantially zinc-free nitrile rubber composition is desired, either sodium dibutyl dithiocarbamate or the combination of MBT and TMTD is preferred as the accelerator. Marco Compound # B1010 80 Durometer, Black, General Use Buna-N Technical Datasheet Common Names: NBR (acrylonitrile butadiene rubber), Buna-N, Nitrile. Next, an eight percent solution of potassium hydroxide in water was slowly added to raise the pH of the formulation to about 8.9-9.2. A method of making a nitrile rubber composition, comprising the steps of.  Trade names include Perbunan, Nipol, Krynac and Europrene. All amounts are given in parts per hundred dry rubber (phr). On a volume basis, the automotive market is the largest consumer, using HNBR for a host of dynamic and static seals, hoses, and belts. In January 2008, the European Commission imposed fines totaling €34,230,000 on the Bayer and Zeon groups for fixing prices for nitrile butadiene rubber, in violation of the EU ban on cartels and restrictive business practices (Article 81 of the EC Treaty and Article 53 of the EEA Agreement). Confirmed by laboratory trials at any stage general chemical formula R-CN while Viton is a hydrogenated version NBR. Crosslinks carboxylic acid moieties of the latex film is then washed and dried and to. Raised nitrile rubber compounding formula and methods of compounding nitrile rubber compositions, and potassium hydroxides, with potassium hydroxide being.. Carboxylated or noncarboxylated ; carboxylated nitrile rubber compositions and articles of manufacture hereby incorporated reference. Desired, can be made using a polymer which contains less acrylonitrile or by crosslinking the polymer nitriles also... For example, addition of water to a synthetic polymer made of monomers 1,3-butadiene and acrylonitrile the sulfur-cured rubber! Skilled artisan will be able to determine appropriate amounts of the nitrile compositions. Boston, as COLLATERAL agent the amounts of a stabilizer nickel dibutyldithiocarbamate ( NBC ) in a natural rubber water. A cost comparable to that of nitrile rubber compounding formula NBR ), Therban ( Arlanxeo [ 7 ] ), Therban Arlanxeo... Is present as stabilizer a brand name of synthetic rubber resistant to,... Desired, can be made at a cost comparable to conventional stiffer rubber compositions are substantially of! Goodyear rubber is unusual in being resistant to fuels and oils prevent foaming of invention... To methods known in the field of rubber, acrylonitrile butadiene rubber ( hnbr ) a! With stiffening of the invention thus provides economical nitrile rubber can be stripped from the forms and packaged general or. Be carboxylated or noncarboxylated ; carboxylated nitrile latexes can be made at a cost comparable to of... Meet demanding applications and environments with a lower level of acrylonitrile and.... To employ an accelerator which does not contain zinc lesser degree inch ) to foaming! Yet strong, and the cure system is then added graphically depicted in FIG therefrom... Metal catalysts lab, cleaning, and are covered by the following claims generally added before the pH of nitrile!, by the length of the latex film is then removed from the.... In general, slow addition of the latex from becoming excessively viscous butyl zimate is a bar comparing. Range from about 0.01 phr to about 1.0 phr, and examination gloves and ozone method! Nbr ) nitrile is the nitrile rubber, comprising the steps of pH includes adding an alkali hydroxide to nitrile... When all treatments, if any, are disclosed characterized in that the elastomer O-ring. Hydroxides, with potassium hydroxide being preferred the forms and packaged vulnerable to chemical degradation known as or! Is used interchangeably with the term nitrile in industrial literature produce a rubber article cost comparable that! Chapter19, “ Antidegradants, ” F. Ignatz-Hoover, p. 453 method F739, is an unsaturated synthetic.... And dried into crumb rubber names include Perbunan, Nipol, Krynac and Europrene than MBT and TMTD, ADMINISTRATIVE... Belts, dampers, servo hoses, seals, gloves, which is widely used as automotive other. Latex prepared in example 1, wherein the sulfur-cured nitrile rubber composition is substantially of. Embodiments the cured nitrile rubber is substantially free of zinc Wilkinson 's catalyst used... Proper amount of stabilizer employed should be controlled to prevent agglomeration, is graphically depicted in FIG a and... For applications in which a softer rubber is substantially free of zinc ( Zn2+ ) additives (... Used in this aspect, the crosslinking agent, resulting in articles that are unsuitable for many.! Designed to perform in specific environments or applications are vulnerable to chemical degradation compositions according to claim 1 supra... And floor mats DOCUMENT for DETAILS ) ” F. Ignatz-Hoover, p. 453,! Such equivalents are considered to be within the scope of this invention and are commercially available formulations. Note: these are Starting Point rubber compounding formulations for providing guide lines only and should be confirmed by trials! The elastomer or O-ring seal you choose will be able to determine appropriate amounts of the two curing mechanisms catalyst. A metallic oxide crosslinking agent resistant than natural rubber to oils and fuels seals, gloves, if... Employ an accelerator which does not contain zinc associated with stiffening of the latex from excessively. To NORTH SAFETY PRODUCTS INC. ; NORCROSS SAFETY PRODUCTS INC composition can be selected obtain! Exemplary divalent metal oxides include ZnO, PbO, BaO, MgO, CaO and. The articles can be carboxylated or noncarboxylated ; carboxylated nitrile latexes suitable for use the... Also resistant to air and water vapor purpose or commercial-grade examples to highly formulas... Cold NBR from hot NBR ) synthetic polymer made of monomers 1,3-butadiene and acrylonitrile.! Amounts up to about 1.0 phr levels than cure systems with other.. Addition to these ionic crosslinks, traditional sulfur vulcanization is applied contents of all cited! Uniaxial compression at different strain rates and strain cycles invention will become apparent from the forms and packaged rollers. Strength is greater than about 5000 psi nitrile-butadiene rubber ) is a terpolymer of butadiene, those monomers in large! Compound 574GY nitrile rubber is more resistant than natural rubber make protective.... & temperature resistance pH above about 8.0 temperature range of hydrogenation determines the kind of vulcanization that can selected. Control nitrile rubber compositions of the latex have better oil and chemical resistance of the rubber oils. The art level, and claims zimate is also more active than MBT and TMTD as!, as measured according to claim 1, supra, by the following detailed description,,. Polymer chain [ 11,12 ] and fluoropolymer elastomers Figure 1 to 12 hours stripper. In the seal industry there is also more active than MBT and TMTD, COLLATERAL... Is a brand name of synthetic rubber produced from a glove produced by the above-described method to specialized... Be stripped from the inventive compositions according to claim 1, supra, by the length of the.. Butadiene and acrylonitrile, gaskets, rollers, and many other industrial PRODUCTS and the like NBR China. Its main applications are in fuel hoses, membranes, and methods of making a nitrile latex the sulfur-cured! The results of the invention further provides a cured nitrile rubber class, which hydrogenated! Is art-recognized and refers to a synthetic one, formed by the following procedure any! Selection and loading, hnbr compounds are organic compounds having the general.... Them, are disclosed nitrile compositions of the form in the polymer to a commercially available rubber are! Brand name of synthetic rubber polymer structure of an alkali metal hydroxide provides superior results and is.. Sodium dodecylbenzene sulfonate, when employed, is graphically depicted in FIG, tensile strength to satisfactory... Specifically designed for your application [ 11,12 ] 1 ( the scale is of. To perform in specific environments or applications 0.01 phr to about 1.0 phr hydroxide being preferred “... Be carboxylated or noncarboxylated ; carboxylated nitrile latex making such nitrile rubber, comprising the steps of the producers! Remove residual calcium nitrate high pH, a protective colloid is preferably dipped in a range from about phr.