Resorcinol-formaldehyde-latex adhesive

The most common adhesive system used for bonding continuous fibers and fabrics to rubber is resorcinol-formaldehyde latex (RFL) system. In general, RFL system is a water-based material. Different lattices including nitrile and SBR are used as the latex for the adhesive system. 2-Vinylpyridine-butadiene-styrene is the common latex used in the adhesive recipe. RFL system is widely being used in tires, diaphragms, power transmission belts, hoses, and conveyor belts because of its dynamic properties, adhesion, heat resistance, and the capacity to bond a wide range of fabrics and mbbers. 

Resorcinol formaldehyde latex (RFL) cord dips have only a limited application within the general rubber goods industry and for adhesion to be achieved with synthetic fibres it is necessary to use the systems developed by Bayer and Degussa. These systems are based upon a combination of resorcinol, a formaldehyde donor and a hydrated silica filler (commonly called the RFK system). This system is incorporated as dry ingredients into the rubber compound and is activated by the application of heat. 

Resorcinol + formaldehyde Melamine + formaldehyde Latex adhesive for tire cord Laminating resin Water Water NH4OH NaOH Atm Ambient Spray dried, or used as a solution Not isolated but used as a solution... 

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... 

As with most rubber composites the adhesion system used in power transmission belts is based on an resorcinol/formaldehyde/latex (RFL) type system. General overviews of RFL adhesion systems from a tyre cord perspective have been previously published by Takeyama and Matsui [31], and more recently by Solomon [32]. Bonding with RFL systems is achieved through applying an RFL coating to the fibre structure prior to the... 

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. 

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... 

Two papers, by separate groups working simultaneously, described the structure of the resorcinol-formaldehyde-latex (RFL) adhesives used for bonding rubber to tire cords. Rahrig [565] suggested that the RFL adhesives are two phase systems with an interpenetrating network... 

The tire cord fabric is pulled of woven fabric and passes through an impregnating bath with a resorcinol-formaldehyde-latex solution that improves the adhesiveness on the rubber. This impregnating is sufficient for viscose and polyamide, but polyester and aramid have to be pretreated additionally with bonding agents based on epoxy resin. 

Tire Cord. Melamine resins are also used to improve the adhesion of mbber to reinforcing cord in tires. Textile cord is normally coated with a latex dip solution composed of a vinylpyridine—styrene—butadiene latex mbber containing resorcinol—formaldehyde resin.. The dip coat is cured prior to use. The dip coat improves the adhesion of the textile cord to mbber. Further improvement in adhesion is provided by adding resorcinol and hexa(methoxymethyl) melamine [3089-11 -0] (HMMM) to the mbber compound which is in contact with the textile cord. The HMMM resin and resorcinol cross-link during mbber vulcanization and cure to form an interpenetrating polymer within the mbber matrix which strengthens or reinforces the mbber and increases adhesion to the textile cord. Brass-coated steel cord is also widely used in tires for reinforcement. Steel belts and bead wire are common apphcations. Again, HMMM resins and resorcinol [108-46-3] are used in the mbber compound which is in contact with the steel cord to reinforce the mbber and increase the adhesion of the mbber to the steel cord. This use of melamine resins is described in the patent Hterature (49). 

A mixture of rubber latex and resorcinol-formaldehyde resin used to treat man-made and synthetic textiles to improve rubber/textile adhesion. 

SRF. [S nectady] Resorcinol formaldehyde preform resin sol n. bonding agent ukd in rubber compds. to improve adhesion resorcinol donor in re-sordncd-formaldehyde latex dips. 

Application of solubility parameter match is also demonstrated in adhesives for polyester tire cord. Whereas resorcinol-formaldehyde resin is used in conjunction with polyvinylpyridine latex as an adhesive for rayon tire cord, this composition is not suitable for poly (ethylene terephthalate) (PET) cord. However, using hexylresorcinol rather than resorcinol results in a match of the solubility parameters of adhesive and fiber with resultant increased adhesion (21). 

Rubber products such as tyres, belts and hose rely on reinforcement by textiles to achieve the required physical properties. To effect reinforcement, textile and rubber must be adequately bonded together, and to promote adhesion, there is a range of treatments to suit most fibre-rubber systems. The adhesion-promoting material (dip) is usually a terpolymer latex of butadiene-styrene-vinyl pyridine (or a blend of SBR and vinyl pyridine), which bonds well to the fibres, together with a resorcinol formaldehyde precondensate, which, on curing, bonds well to mbber a three-dimensional resin network is formed. 

NBR latices can be also used in adhesive applications. The use of latex has the advantage of avoiding the previous solution of the polymer before application and has favourable environmental treats. Compounding with a resorcinol-formaldehyde solution allows to bond nitrile rubber to cotton or rayon fabric. Nitrile latex can be mixed with PVC latex to give excellent adhesion of polypropylene carpet and plywood backings. Combinations of nitrile latices and styrene-butadiene latices provides good laminating bonds for saturated paper and woven fabrics. 

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