Cross-linking acrylic coatings

Cross-Linking of Acrylate Resins. In contrast to thermoplastic polymers, cross-linked polymers are insoluble and are also harder and more resistant to chemicals these properties are extremely important for high-grade coatings. Cross-linking reac-... 

One approach to solving these problems is to combine conventional polyisocyanates with conventional, amine neutralized, water-reducible resins in a water-miscible solvent and then add water. A similar process is used for water-reducible coatings cross-linked with MF resins. Conventional water-reducible acrylic resins in solvents such as l-methoxy-2-propanol acetate have been used. Water-soluble... 

Some polymers like PE and NR get cross-linked on exposure to radiation while others like those based on vinylidene polymers, e.g., polymethylmethacrylate (PMMA), polyisobutylene, degrade. Certain other types of polymer stmctures (high aromatic content or thermoset) resist degradation by high-energy radiation. Coating polymers usually contain acrylic, methacryUc, or fumaric vinyl unsaturation along or attached to the backbone. 

Figure 7. Elastically effective cross-link density versus bake temperature for an acrylic-urethane coating as a function of polyol to isocyanate ratio.

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