Brass adhesion stearate

Differences in efficiencies between cobalt adhesion promoters is due to the ease with which Co + ions can be formed. For example, zinc or brass reacts more easily with cobalt boron decanoate complexes tihan with cobalt naph-thenate or stearate. The Co + and Co + ions are incorporated into the ZnO film before the sulfide film has been built up. Both di- and trivalent cobalt ions reduce the electrical conductivity of the ZnO lattice, thereby reducing the diffusion of Zn + ions through the semiconducting film. 

Cobalt is important to the rubber industry to promote rubber-to-metal adhesion. The use of cobalt salts, such as cobalt stearate or cobalt naphthenate as compounding additives, will promote better adhesion between cured rubber and brass-coated steel tire cord. 

Cobalt salts such as cobalt stearate are commonly used as rubber compound additives to supplement the HRH components for better rubber-to-brass-plated steel tire cord adhesion. 

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. 

Cobalt Salts. Barker" studied the effects of cobalt stearate, cobalt naphthenate, and a proprietary boron-containing metal-organic complex on adhesion to brass. He concluded that, with properly optimized compounds, little or no benefit is obtained from the use of cobalt insofar as initial adhesion is concerned. All salts, however, improved steam-aged adhesion to some extent. Other studies tend to support these claims. 

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