Nylon cord bonding

Condensed Tannins as Substitutes for Resorcinol in Bonding Polyester and Nylon Cord to Rubber... 

Hamed G R, Chung K H, Hemingway R W (1989) Condensed tannins as substitutes for resorcinol in bonding polyester and nylon cord to rubber. In Hemingway R, Conner A H (eds) Adhesives from renewable resources. ACS Symp Ser Washington DC 242-253... 

The nature of the fiber plays the most important role in RFL treatment of tire cords. We know that rayon and nylon cords are easy to bond to rubber by RFL treatment, but polyester cord is extremely difficult. This can be attributed to the nature and structure of the fiber. 

Considering plastic substrates, Pritchard [97] cites the dipping of nylon cords into a complex adhesive mixture of rubber and resorcinol-formaldehyde, as used in the production of tyres, as an example where hydrogen bonding may... 

Adhesion. Commercially available 1- or 2-coat adhesive systems produce mbber failure in bonds between ethylene—acryflc elastomer and metal (14). Adhesion to nylon, polyester, or aramid fiber cord or fabric is greatest when the cord or fabric have been treated with carboxylated nitrile mbber latex. 

The carcass or body ply of the tire is made up of fabric yams, typically of steel, nylon, rayon, or polyester, twisted into parallel weft-less cord layers known as plies. These plies are loaded with NR-based compound loaded with adhesion promoters to generate a bond between the cord surface and other tire components. 

Materials. Two types of standard tire cord obtained from Gen Corporation were used in this investigation polyester, 1300/3, and nylon 66, 1260/3. The rubber composition to which the adhesively dipped cords were bonded had the following composition in parts by weight styrene-butadiene rubber (SBR) 1502, 100 N330 carbon black, 50 zinc oxide, 5 stearic acid, 0.5 sulfur, 1.7 2-morpholinothio-benzothiazole, 2. Master batches were mixed 7 min in a 350-ml Brabender Plasticorder, and curatives were added on a cool two-roll mill. Cure characteristics at 155 °C were determined with an oscillating disc rheometer (ASTM D 2084). The time to reach 90% of the final cure state was 23 min, and the Shore A hardness of the final vulcanizate was approximately 60. 

Condensed tannins have considerable promise as substitutes for resorcinol used in resin formulations for bonding of nylon or, particularly, polyester cord to rubber. Although much more work needs to be done, preliminary results suggest that refinement of extract properties and adhesive formulations could lead to a large, high-value market for condensed tannin extracts. 

A modified ebonite method was developed [134] to study the interfaces associated with polymer tire cords. Hre cords composed of PET, rayon or nylon fibers are generally bonded to rubber with a resorcinol-formaldehyde-latex (RFL) adhesive. The nature of the interfaces is of interest in tire... 

A modified ebonite method was developed [113] to study the interfaces associated with polymer tire cords. Tire cords composed of PET, rayon or nylon fibers are generally bonded to rubber with a resorcinol-formaldehyde-latex (RFL) adhesive. The nature of the interfaces are of interest in tire cord studies. OSO4 may be used to stain and harden the RFL, but the soft rubber is not affected by this treatment, and, in fact, it forms a barrier to stain penetration. The ebonite reaction hardens the rubber and hardens and stains the RFL while maintaining the geometrical integrity of the composite. 

The most common textile bonding compositions are, of course, the RFL (resorcinol-formaldehyde-latex) dips used to adhere tire carcass rubber to cord reinforcing members. A typical RFL composition calls for a latex terpolymer of styrene-butadiene-vinyl pyridine as well as the resorcinol and hexamethylene tetramine. Some natural rubber latex or regular SBR latex may also be added. The R F resin which forms in situ is able to react chemically with rayon by methylol etherification of the cellulose s hydroxyls. Similar reaction is likely with the amide groups of nylon fibers as shown in Figure 7. 

Tire Cord Dip. Tire cord adhesives is another important outlet for latexes. A basic formulation is given in Table 4. The latex is mainly a vinyl pyridine (VP) type. Depending on the fiber to be bonded, the VP latex can be diluted with hot SBR or nonagglomerated cold SBR latex. The dilution depends on the difficulty of bonding the different fibers. Rayon was easy to bond to the carcass and did not require VP latex. Substitution of rayon by nylon and polyester tire cords necessitated the development and use of VP latex. 

Dispersions of copolymers of butadiene with acrylic acid or methacrylic acid in aqueous potassium hydroxide have been mentioned in the patent literature" as a dip for adhering rayon tire cord to rubber. The effect is most evident when carboxyl groups are present in the adhesive, the tie cement, and the cover stocks. The adhesive may be applied as latex, aqueous dispersion, or cement. A patent issued to the Dunlop Company Ltd." describes the use of a styrene-butadiene-itaconic acid copolymer with Gen-Tac Latex (GenCorp) in formulating an RFL (resorcinol formaldehyde latex) type adhesive for bonding a natural rubber compound to Nylon 66 and rayon tire cords. Brodnyan" also claims carboxylic adhesives for rayon, nylon, and Dacron cords. In this case, the tire cords were treated with a mixed polymer latex containing resorcinol-formaldehyde condensate, a butadiene-vinyl pyridine copolymer, an SBR copolymer, and a multifunctional copolymer from methyl acrylate, 2-hydroxy propyl methacrylate, and acrylic acid. A different approach was reported by Badenkov" whereby rayon or nylon tire cords were coated with... 

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