Rubber tire cord adhesion

Properties Permanently fusible sol. in water, ketones, alcohols Uses Adhesion promoter, bonding agent for rubber compds., latex dips, for bonding syn. industrial fabrics to rubber, adhesives in wood gluing, esp. marine plywood saturant water-resistant additive for starch adhesives tackifier for nitrile rubbers tire-cord adhesive adhesive dips for mech. goods, fabrics, V belts Manuf/Distrib. Indspec... 

Ellul, M.D. and Emerson, R.J. (1988a). A new pull-out test for tire cord adhesion-Part I, Hot bonding. Rubber Chem. Technol. 61, 293-308. 

Pullout Tests. The method to determine the adhesion between the dipped cords and the SBR vulcanizate was the tire cord adhesion test (L/,75), Figure 1. Here, two cords are embedded (to a depth of 10 mm) into opposite ends of a rubber block (76 mm x 13 mm x 6.4 mm). Samples are then cured 23 min at 155 °C and allowed to rest 1 day. Bond strengths are determined by clamping the two free cord ends in an Instron and pulling at the rate of 50 mm/min. 

The adhesive properties, coupled with the fact that monomer I was shown to be a vulcanizing agent for rubber (15), indicated that the polymer might make a suitable tire-cord adhesive. The data in Table III demonstrate the adhesive properties of the polymer, which may be data and R. Kindle for the adhesion data. Irradiation work was done by D. I. Relyea at the Uniroyal Reseach Center in Wayne, N. J. 

Copolymerization studies demonstrated that aminimide, 1,1-dimethyl-l-(2-hydroxypropyl)amine methacrylimide (DHA) copolymerizes readily with 4-vinylpyridine (4VP) and N-vinylpyr-rolidone (NVP). These copolymers could he thermolyzed in solution to give soluble poly(4-vinylpyridine-co-isopropenyl isocyanate) and poly(N-vinylpyrrolidone-co-isopropenyl isocyanate) materials. The reactivity ratios of each monomer pair were determined, and the Alfrey-Price Q and e values for DHA were calculated for DHA (Mt)-4VP (M2), r, = 0.41, r = 0.77, Q = 0.68, and e = 0.58 and for DHA (Mt)-NVP (Mg), r2 = 0.15, r2 = 0.35, Q = 0.14, and e = 0.58. The DHA-4VP copolymers quaternized readily to give a new family of water-soluble polyelectrolyte materials. The various copolymers were examined as adhesion promoters for rubber-tire cord composites. 

One of the main points of debate w ith the above methods is the stress distribution due to gripping the rubber block. Nicholson ct al. [41.42] used a test with two cords embedded in the block of rubber and avoided holding the block in one grip of the testing machine. Further analysis was made by Brodsky [43], who used three cords. Ellul and Emerson [44.45] used cords embedded in steel enclosed rubber cylinders with alternatively hot and cold bonding. Ridha et al. [46] have calculated the stress fields in tire cord adhesion test pieces, and Mollet [47] has compared the various methods. 

The use of EPDM rubbers for the manufacture of automobile and truck tires has not been successful, mainly because of poor tire cord adhesion and poor compatibility with most other rubbers. However, EPDM rubbers have become widely accepted as a moderately heat-resisting material with good weathering, oxygen, and ozone resistance. They find extensive use in nontire automobile applications, including body and chassis parts, car bumpers, radiator and heater hoses, weatherstrips, seals, and mats. Other applications include wire and cable insulation, appliance parts, hoses, gaskets and seals, and coated fabrics. 

Where straight resorcinol adhesives are not suitable, resins can be prepared from modified resorcinol [13], Characteristic of these types of resins are those used for tire cord adhesives, in which a pure RF resin is used, or alternatively, alkyl resorcinol or oil-soluble resins suitable for rubber compounding are obtained by prereaction of resorcinol with fatty acids in the presence of sulfuric acid at high temperature followed by reaction with formaldehyde. Worldwide more than 90% of resorcinol adhesives are used as cold-setting wood adhesives. The other most notable application is as tire cord adhesives, which constitutes less than 10% of the total use. 

The thin coating of brass on the steel cord is the primary adhesive used in steel-to-rubber bonding. The quality of this bonding system built up during vulcanization of, for example, a radial tire will influence the performance of the steel ply or steel belt in the tire and, ultimately, the durability of the product. Though the mechanism of bond formation in rubber-steel cord adhesion is very complex, a brief review of the current understanding of wire to rubber adhesion is presented. 

The reaction medium consists of molten sulfur/accelerator (N,N-dicyclohexyl-2-benzo-thiazolylsulfenamide)/zinc stearate in the weight ratio 90/5/5. Small pieces of the cord are cut from the tire carefully trimming some of the rubber but leaving a thin, undisturbed surface layer. Eight hours are required for the reaction at 120°C. Samples are removed, scraped off and placed in a 120°C oven to remove the excess ebonite. The treated cords are embedded and sectioned with a diamond knife to reveal the interfaces that relate to the adhesive coating and the tire cord adhesion. The fiber-RFL-rubber interfaces are all observed in the tire cord cross section (Fig. 4.14). A more complete description of this type of study is described in Chapter 5. 

McCarvill and Bell ° have described the use of torsional test for the determination of adhesive joint strength, and dynamic loss has been used to measure tire cord adhesion to rubber. Holographic method has been suggested as one non-destructive method for... 

T. Murayama and E. L. Lawton, "Dynamic Loss Energy Measurement of Tire Cord Adhesion to Rubber", J. Appl. Poly. Sci., 17,... 

Although this paper does not deal with the tire cord adhesives, the use of the steel belt in the newer radial tires and in truck tires has Indicated a need for better adhesive systems and methods of testing the steel cord to rubber adhesion. ... 

Originally the tire industry used straight resorcinol as the R component in the HRH compound for good steel tire cord adhesion. However, with environmental and safety concerns in handling free resorcinol in the rubber mixing operations, resorcinol is now used in the tire and rubber industry as a solid resorcinol formaldehyde resin (or RF resin), which is somewhat safer to work with. 

Resorcinol formaldehyde resin is a vital ingredient in the HRH rubber adhesion compounds (such as wire coat stock or breaker stock) in order to achieve good rubber-to-brass-coated steel tire cord adhesion. 

Resorcinol formaldehyde resin is an extremely important component of the HRH system for achieving good rubber-to-brass-plated steel tire cord adhesion. This RF resin functions as a resorcinol donor in the rubber compound that reacts with the... 

RF resin has been used to achieve good rubber-to-brass-piated steei tire cord adhesion since the 1960s. There are very few aiternatives, and these aiternate substitutes may not reaiiy be viabie in the iong term. 

Cobalt stearate (or other cobalt salts) is sometimes used as rubber compounding ingredients to improve rubber-to-brass steel tire cord adhesion under certain circumstances. Commonly, a careful use of cobalt soap such as cobalt stearate may actually improve certain adhesion characteristics if it is used properly. Since rubber-substrate adhesion is a variable phenomenon, many technologists feel that the contribution of cobalt is to improve the reliability of the adhesion rather than the adhesion per se. Over the past three decades, this reliability of adhesion has been found to be of much importance in the manufacture of steel-wlre-reinforced tires and other rubber products. Thus the end result is a greater consistency of product quality, with fewer production rejects and subsequent failures in actual service. 

While it is possible to get some adhesion using HRH without the hydrated silica, many times insufficient adhesion is imparted. Thus hydrated precipitated silica is a very important component of the HRH system if it is used to achieve adequate rubber-to-metal adhesion. This is particularly true with rubber-to-brass-coated steel tire cord adhesion where there are very few practical alternatives. 

Benzene is used as a feedstock to produce resorcinol, a very important chemical that is used to manufacture resorcinol formaldehyde (RE) resin for RFL dips for tire cord adhesion, as well as RF resin for HRH adhesion systems for rubber-to-metal adhesion, and for the production of TIER for curing polyurethane rubber. 

Resorcinol reacts with formaldehyde to produce RF resin for HRH systems in rubber compounds to achieve good rubber-to-metal steel tire cord adhesion, as well as good textile (polyester, nylon, rayon) cord adhesion. 

Sodium sulfite is used to make resorcinol, which is reacted with formaldehyde to produce RF resin, used as a compounding ingredient in HRH systems to achieve rubber-to-metal tire cord adhesion. 

Insoluble Sulfur. In natural mbber compounds, insoluble sulfur is used for adhesion to brass-coated wire, a necessary component in steel-belted radial tires. The adhesion of mbber to the brass-plated steel cord during vulcanization improves with high sulfur levels ( 3.5%). Ordinary rhombic sulfur blooms at this dose level. Crystals of sulfur on the surface to be bonded destroy building tack and lead to premature failure of the tire. Rubber mixtures containing insoluble sulfur must be kept cool (<100°C) or the amorphous polymeric form converts to rhombic crystals. 

Standard Test Method for Adhesion Between Steel Tire Cords and Rubber. Steel cords are vulcanised into a block of mbber and the force necessary to pull the cords linearly out of the mbber is measured as adhesive force. ASTM method D2229-93a can be used for evaluating mbber compound performance with respect to adhesion to steel cord. The property measured by this test method indicates whether the adhesion of the steel cord to the mbber is greater than the cohesion of the mbber, ie, complete mbber coverage of the steel cord or less than the cohesion of mbber (lack of mbber coverage). 

Both natural rubber and SBR are used in Scotch tape, masking tape, and adhesive-backed floor tiles. They are used in automobiles to bond fabric, carpets, and tire cord. 

N326 82 72 Tire carcasses, steel cord adhesion compounds, mechanical rubber goods... 

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