Substituted heat-reactive resin applications

Substituted heat-reactive resins are most widely used in contact-adhesive applications and, to a lesser extent, in coatings (95,96) p-butylphenol, cresol, and nonylphenol are most frequently used. The alkyl group increases compatibility with oleoresinous varnishes and alkyds. In combination with these resins, pheno-lics reduce water sensitivity. Common applications include baked-on and electrical insulation varnishes, and as modifiers for baking alkyds, rosin, and ester gum systems. Substituted heat-reactive resins are not used for air-dry coatings because of their soft, tacky nature in the uncured state substituted nonheat-reactive phe-nolics are the modifying resin of choice in this case. 

Raw Materials Base-Catalyzed Reactions Acid-Catalyzed Reactions Classification of Phenolic Resins Unsubstituted and Heat Reactive Unsubstituted and Nonheat Reactive Substituted and Heat Reactive Substituted and Nonheat Reactive Applications... 

The solubility of phenolic resins in different coating formulations is, however, affected by the type and chain length of substituent groups in the phenols. Depending on whether substituted or unsubstituted phenols are used, the phenolic resins can be further classified into two more groups of heat- and nonheat-reactive resins, having different applications. 

This formulation is laid down by electrophoresis over the material to be coated, acting as the cathode, and finally heat cured. The process requires molecules with chemical structure suitably designed for different applications, and the chemistry of Mannich bases may represent a convenient tool for preparing variously substituted derivatives. In fact, as depicted in Fig. 187, the reactive functions leading to the final crosslinked material may be bound to several different positions of the oligomeric epoxy resin. The Mannich derivatives of bisphenol A (572)2 " - > -2 and nonylphenol (573)202.2a i.2()6 con-... 

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