Pinholes are a problem for formulators developing fast drying, water-based coatings, especially in coatings cured at high temperature and applied at high wet film thickness. Pinholes are often caused by air or solvent vapor release from the film when the coating is too viscous to flow back and repair the holes. Pinholes also occur in bake coatings as the trapped vapor regains mobility when the coating softens under heating, before cross-linking hardens the film preventing flow back into the voids.
Hydrocarbon defoamers help eliminate the foam and pinholes in these formulations, but their limited compatibility results in lower gloss, poor leveling and surface appearance. This paper describes a new additive that combines both deaeration of micro foam and modified surface drying for pinhole elimination. This new additive shows comparable pinhole elimination compared with hydrocarbon-based defoamers, but without compromising formulation compatibility or final coating appearance.
Bio(s) and Job Title(s):
Dr. Jim Reader – Lead Chemist (Evonik Corporation)
Jim Reader graduated from the University of Warwick (UK) in 1988 with a Ph.D. in Chemistry. He joined Air Products and Chemicals in 1988 in Manchester (UK) as a Research Chemist and later an Application Development Chemist for the Epoxy Additives business. He then became Technical Manager for the Air Products Specialty Additives business in 1996 based in Utrecht, the Netherlands, and has worked in Europe and Asia before becoming a Lead Chemist in Allentown, PA in 2008. Dr. Jim Reader joined Evonik Corporation as a Lead Chemist in January 2017. He has extensive experience in the both the development and application of surfactants and defoamers in many different applications including paints, coatings, graphic arts, adhesives, concrete admixtures and the production of latex gloves. He is the inventor of one patent and has written over 20 technical papers.
Powder Coatings have continued to broaden its application to protect a greater range of substrates. With this expansion, more chemistries are being developed for differing substrate compositions. These include lower temperature cure to address heat sensitive substrates and/or lower energy consumption to reduce cost. These applications also require aesthetics that require consistent matte finishes. Although there are several additives technologies being employed, the stringent need for greater uniformity in the final coating is still a challenge.
In this study, the paper reviews the range of available additive technologies that are currently being employed for matting powder coatings, then introduces a novel synthetic silica technology and examines its impact on matting in powder coatings. The study will look at how this influences processing of powder, usage of the novel synthetic silica, main effects on matting and other performance characteristics of the final powder coating. The results will provide a comparable overview of how the new novel synthetic silica performs versus current available technologies.
Bio(s) and Job Title(s):
Bob T. Lin – Sr. Technical Manager (Evonik Corporation)
Bob is a Sr. Technical Manager with Evonik Corporation’s Coatings Additives Business Line. He has twelve years of coatings experience in both polymers and industrial coatings with DeSoto, Inc. and Valspar Corporation. He has worked on the application of silica and carbon black in coatings for over twenty years. He received his B.S. in Chemistry from University of Illinois.
Bernhard Resch – Scientist II (Evonik Corporation)
Bernhard is a Scientist II with Evonik Corporation’s Coatings Additives Business Line. He has extensive powder coatings experience having worked for twelve years with TIGER Drylac and eight years with Akzo Nobel before joining Evonik. His experience in managing production and labs as well as formulating powder coatings and trouble-shooting customer problems gives him broad understanding of powder coatings raw materials, manufacturing and application. He has a degree in Chemical Industrial Engineering from Austria.
Sandeep Bhatt is currently President and Business Director of DSM Specialty Resins for North America. Prior to his current role, at DSM he managed global architectural business as business director and worked as commercial director for North America.
Before joining DSM, Sandeep worked for Cabot corporations globally managing various specialty chemicals segment. He loves to hike with his family and friends.
Andrew T. Carroll
Andrew is the vice president of the industrial coatings business for the United States, Canada and Latin America.
Andrew began his PPG career in 1991 and has held a range of diverse, impactful leadership roles, including R&D chemist automotive OEM clearcoats and electrocoat; technical manager, automotive OEM electrocoat, in Marly, France; account management and business management roles in automotive OEM coatings and PPG TrueFinish light industrial coatings; and director of mergers and acquisitions for industrial coatings. Recently, he was global director of technical and product management for industrial coatings. In March of 2020, he then stepped into his current role as vice president, industrial coatings, Americas.
Andrew earned a B.S. in Chemistry from Penn State and an M.S. in electrochemical engineering, business management and product development from Case Western Reserve University.
Bryan Danek is the North American Sales Director & Global Key Account Director for Croda’s Smart Materials business focused on bringing valued innovations with performance and sustainability into the CASE and Polymer markets. After graduating from Eastern Michigan University with a degree in Polymer and Coating Chemistry, Bryan worked in the technical side of the polymer and paint industry followed by 15 years of various commercial roles within the specialty chemical sector ranging from Applications and Technical Service Specialist to Commercial Business Leader.
Jeff attended Indiana University at Bloomington where he obtained his Master of Science degree in Inorganic Chemistry and Southern Illinois University at Carbondale where he obtained his Bachelor of Science degree in Chemistry.
Jeff joined Polynt Composites in November, 2019. He has over 38 years of coatings experience at various companies including Rust-Oleum, Benjamin Moore, Sherwin Williams, Ameron, BASF and Stepan. He has expertise in formulating urethane, epoxy, polysiloxane, alkyd and water-based acrylic coatings for the general industrial, architectural & flooring markets.
At Polynt, Jeff is a senior technical service representative and uses his expertise for customer formulation development and testing. He also interfaces with research and development to assist in the design of new resins for architectural and industrial applications.