CYCAT 296-9 catalyst is a unique clear liquid acid catalyst used to accelerate the cure of Cymel amino resins at normal baking temperatures and to allow the curing of clear topcoats and enamels in a relatively low temperature range.
Coatings containing CYCAT 296-9 catalyst can be cured on a low temperature baking schedule to achieve the same hardness as similar non-catalyzed systems that require higher temperatures. The corrosion resistance of finishes containing high levels of catalyst can be reduced and should be carefully checked for resistance.
Mabli et al. F 0 studied the effect of surfactants on the viscosity of associative thickener solutions, wax emulsion dispersions and latex paints. At low concentrations of HEUR thickeners, nonionic surfactants increase the viscosity of the thickener solution. At a given volume solid content, the adsorption of HEUR-type homogenizers on the latex particles and the substitution of surfactants from the latex particles are related to the total surface area of the latex. After HEUR thickeners are replaced from 600mm latex particles, they enter the solution and form a network with surfactants to increase viscosity. It is best to use non-ionic surfactants, which have a synergistic effect with low concentrations of large hydrophobic base HEUR thickeners. For 108nm latex, it is mainly the adsorbent that increases the viscosity of the dispersion. It is achieved by increasing the effective volume of the latex and at the same time when the size of the adsorbed HEUR thickener matches the distance between the latex particles with a solid content of 0.25 volume. In typical formulations, there is no case where non-ionic surfactants completely replace the adsorbed HEUR thickeners. Therefore, in fine latex coatings, the substitution is not sensitive to the order of addition.
Cac Kovich et al. L25J believe that when the steric hindrance is stable, the emulsion adsorbs the emulsifier, and the hydrophilic layer points to the water, thus reducing the thickening effect of the associative thickener.
Kost an sek et al. 126] used a phase diagram to show the interaction between associative thickeners, emulsions and surfactants. The phase diagram is divided into bridging flocculation region, good dispersion region and depletion flocculation region. When HEUR thickeners are added to the emulsion, they are adsorbed on the latex particles and connect the latex particles to produce bridge flocculation. Between the particles, due to the osmotic pressure, the unadsorbed thickener molecules are discharged to form vacancies, and the resulting flocculation is called vacancy flocculation.
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