Three BASF researchers received the outstanding paper award Monday at the American Coatings Show in Charlotte, N.C., for their work on the development of high-performance water-borne anticorrosion coatings.
Oihana Elizalde, Stephan Amthor, and Collin Moore received the American Coatings Award for their paper, “Closing the Gap Between Water and Solvent-borne Anti-corrosion Coatings via New Binder Concepts.” The award was presented during ceremonies held on the opening day of the conference, at the Charlotte Convention Center. The conference began Monday, and is being held in conjunction with the American Coatings Show; the events conclude Wednesday.
The events are being presented by the American Coatings Association (formerly the National Paint & Coatings Association and Federation of Societies for Coatings Technology) and Vincentz Network, with show management by NurnbergMesse North America Inc.
The paper, which was presented Tuesday during a conference program session on protective coating, described the authors’ examination of different technologies that can be used to design acrylic binders for anticorrosive metal coatings that offer improved barrier properties, low water uptake, and improved anticorrosion properties. Elizalde and Amthor are based at Ludwigshafen, Germany; Moore is based in Wyandotte, Mich.
BASF said recent innovations in polymer colloids and hybrid materials offer opportunities to develop new coatings for metal protection. Among the different methodologies explored in the paper are designed particle morphology, engineering of the water-phase composition, and the use of hybrid binders.
The researchers also examined a new technology that utilizes a built-in, enhanced corrosion-protection mechanism that contributes to strong performance results in salt-spray and early-rain resistance, BASF said.
“Since the invention of emulsion polymerization, water-borne materials have been developed in coatings for the purpose of replacing solvent-borne systems in the market and reducing our impact on the environment,” said Elizade, who presented the paper. “Nothing is greener than water.”
But Elizade added that “after 40 years of intense effort, there is still a performance gap between water-borne and solvent technologies, despite varying monomer composition, surfactant and feed methods.
The paper described the development a of hybrid binder (resin) system in which the researchers sought to retain the advantages of acrylic resins—including flexibility, adhesion, and film formation—while augmenting the technology with the properties of a second resin that contributes to anticorrosion protection. Two different chemistries were employed as the second resin in the hybrid system—a highly hydrophobic polymer characterized by low water uptake and strong barrier properties, and an alkyd resin also characterized by superior chemical resistance and barrier properties.
The paper described test results comparing water-borne coatings formulated with the hybrid resin and conventional coatings based on a styrene-acrylic resin. The authors found that anticorrosion performance was markedly stronger for coatings formulations based on the hybrid resin that was synthesized using an acrylic resin and the hydrophobic polymer. Formulations based on a hybrid acrylic/alkyd resin system also demonstrated strong anticorrosion properties in accelerated testing.
The paper also reviewed advances in the design of high-performance water-borne “structured” styrene-acrylic resins that were used as components of the hybrid resin systems. A key advance discussed in the paper involves resins that act as both barriers and inhibitors to corrosion. Such “structured” polymers are based on “core-shell” morphology, in which the polymer core provides hardness and durability, while the shell contributes film elasticity and coalescence. The paper also described the development of a new technology that improved the performance of these structured polymers by building corrosion-inhibiting functionalities into the resin composition.
Also discussed in the paper was development work that sought to optimize film formation by means of polymer design, cosolvent choice, and minimization of water-soluble components in the resin. Finally, the paper described the superior performance of coatings based on novel hybrid resins synthesized by combining acrylic polymers with the hydrophobic polymer or alkyd resin.
BASF said that as a result of this research described in the paper, new resins for water-borne anticorrosion coatings are being introduced. They include a styrene-acrylic emulsion for metal primers and an acrylic emulsion.