WSU inventors have developed epoxy resin systems and carboxylic terminated polyesters using rosin acids as building blocks. This provides a method to make epoxy resin systems that do not contain Bisphenol A (BPA). Current powder coating polyester resins are built largely on tere-or isophthalic acid and trimellitic anhydride as rigid monomers together with other reactants. The epoxy resin is either diglycidyl ethers of bisphenol A or epoxy-novolac resin, both are based on the phenol building block.
Rosin and derivative as adhesive tackifier is a well-established practice, and they have also found many other niche applications in inks, varnishes, paints, sealing wax, adhesives, some soaps, dressing for machine belting; paper sizing; soldering, plasters, etc. With an annual global growth of 7 percent, powder coating is the fastest growing business in coating industry. The global powder coatings market was $3.3 billion US dollars in 2002. Production reached more than 1.46 million tons in 2006 and has increased to more than 2.3 million tons in 2010. Among other advantages, the solvent-free process, ease of application, and few wastes are most impressive. Powder coatings include epoxy, polyesterepoxy, polyester, polyurethane, acrylic and others. Polyester epoxy hybrid coating takes almost half of total market. Powder coating is widely applied in automotive, furniture, wood, construction, appliance industries.
Applications and Advantages
§ environment-friendly procedure and non-hazardous product output to humans
§ wide application due to enhanced properties: great peeling properties and impact strength
US and PCT applications pending
Honghua Wang, Bo Liu, Xiaoqing Liu, Jinwen Zhang and Ming Xian. Synthesis of Biobased Epoxy and Curing Agents using Rosin and the Study of Cure Reactions. Green Chem., 2008, 10, 1190-1196