Water-Based Core Shell Acrylic and Alkyd Hybrid Resins

  As environmental and human health concerns have grown in importance, water-based alternatives with lower VOC (Volatile Organic Compounds) content have begun to be developed to replace existing solvent-based products. The primary goal in this process is to develop water-based products with performance equal to or better than solvent-based products. Each polymer has its own advantages and disadvantages. Thanks to hybrid polymer technology, properties of multiple polymers are being combined in a new polymer to develop higher-performance polymers. These new hybrid polymers have given paint manufacturers the opportunity to develop higher-performance products. Alkyds have the fundamental advantage of forming excellent films, adhering well to many surfaces, having flexible structures and drying by air oxidation. The drying time and yellowing problems that are shortcomings of alkyds are compensated by the advantages of acrylics—fast drying and yellowing resistance—to create a new polymer called a hybrid polymer.

Method

In the physical mixture of acrylic and alkyd, incompatibility occurs due to molecular separation, and the expected performance from the combination cannot be achieved. For this reason, they must be produced in a chemically compatible manner. Generally, two production methods can be mentioned: micro-emulsion and dispersion techniques. Without going into method details, briefly speaking, for these processes, the selection of the correct alkyd and monomers, the surfactants that will hold them together, and the initiator determine product properties. The selected monomer property determines the final form of the newly created polymer. Desired properties such as hardness, gloss or flexibility are provided by the selected monomer combination. Cross-links created through hybrid structures supported by functional monomers make it possible to obtain higher-performance products. The reason acrylic-alkyd hybrid technology is called Core Shell is that alkyd polymers in the core are wrapped with acrylic polymers. Thanks to this technology, high-performance polymers with lower VOC content are being developed.  

Application Areas

The application areas of acrylic-alkyd resins developed with Core Shell technology vary depending on the alkyd type and the properties of the selected monomer. They are used in decorative paints, industrial metal coatings, wood paints and varnishes. For metal applications, the alkyd-styrene combination is a good alternative due to both corrosion resistance and adhesion properties. In exterior wood applications, excellent solutions are being developed with acrylic-methacrylate or soft monomer combinations. Additionally, Core Shell polymers made using reactive monomers that create cross-links for special industrial coatings offer superior performance.

Other Core Shell Hybrid Technologies

In acrylic-alkyd hybrid systems, depending on the alkyd type (medium oil, short oil or urethane) and the selected acrylic monomers (hard, soft or functional), many alternative polymers can be created. Beyond these, applications such as urethane-acrylic hybrid, epoxy-acrylic hybrid and silicone-acrylic hybrid are developing day by day. The adhesion, chemical and impact resistance properties of epoxies and their success in metal and substrate applications produce very good results when applied as hybrid with acrylic. Similarly, excellent results are emerging in Core Shell polymerization of urethane and silicone resins with acrylics. As a conclusion; water-based products developed with the new Core Shell technology will now provide advantages over solvent-based competitors and will be environmentally-friendly alternatives with low VOC emission. With the increase in sales of new technology products and product variety, the cost difference between solvent-based products will narrow. Water-Based Acrylic-Alkyd Hybrid Resin Advantages and Disadvantages of Acrylics and Alkyds Alkyd properties: Gloss Adhesion Film formation Flow Penetration Corrosion resistance Acrylic properties Fast drying UV resistance Disadvantages: Poor film Adhesion Peeling, Cracking Disadvantages: Yellowing Slow drying, hardening Kenan Bayraktar - General Manager - SUBA Kimya Teknolojileri San. ve Tic. Ltd. Şti.