Session V: Architectural Coatings
Chair: Alvin C. Lavoie, Ph.D. , Global Technology Director Paint and Coatings Materials Architectural Coatings, Rohm and HaasTuesday Morning 9:00 a.m. – 12:30 p.m.
Breakout Room 217 A/B
Challenging the architectural coatings world to achieve the Next Level, there is continued intense effort to close the performance and application properties gap between waterborne systems and conventional solvent-based systems even further. Different approaches to achieve high-performing, yet low or no VOC systems are discussed in this session. Examples include acrylic hybrid resins, formaldehyde-free, non-yellowing new reducing agents for water based polymers, modified hyperbranched resins, as well as a new class of rheology modifiers made by controlled radical polymerization methods. | ||
5.1 9:00 – 9:30 a.m. Waterborne Alkyd Dispersion Technology for Low VOC Stainblocking Primers Neal Rogers*, Kyu-Jun Kim, Amanda Mann, Cook Composites and Polymers Alkyd dispersion resins offer a waterborne low VOC alternative to acrylic emulsions designed to enhance stainblocking primer performance. Although acrylic emulsions are capable of low VOC formulation with suitable stainblocking, there remains a performance gap between waterborne acrylics and conventional alkyds. SCAQMD has adopted a 100 g/l limit for architectural primers which precludes the use of solventborne systems. A review of stainblocking mechanisms comparing coalescing dry of acrylic emulsions versus catalyzed oxidative dry of alkyd systems is included. The use of water as the predominant solvent and the speed of coalescence impacts performance of acrylic emulsion systems. Conventional vinyl-toluene modified alkyds in mineral spirits offer rapid dry in a non-polar solvent which contributes to excellent stainblocking performance. This study explores alkyd-acrylic hybrid resin approaches in stainblocking primers. Alkyd dispersion resin systems with varying alkyd-acrylic content and acrylic monomer composition are compared for dry, tannin blocking, ink stainblocking and adhesion performance. | ||
| 5.2 9:30 – 10:00 a.m. Zero VOC Alkyd Latex – Surpassing VOC Requirements in Architectural Applications Carl Sullivan*, Mihaela Coman, Reichhold Inc. Waterborne alkyd latex products offer the unique capability of providing the benefits of alkyd resins at VOC levels that are well below current requirements for architectural coatings. In addition, alkyd latex products that use water only as a carrier – no organic solvent – are inherently zero VOC and therefore enable coating formulators to develop products that are well ahead of future regulations. High gloss trim enamels with less than 50 g/l VOC can be formulated with alkyd latex products. Performance of these prototype coating formulations is benchmarked against commercially available acrylic latex gloss enamels. In addition, comparison to a solventborne alkyd high gloss trim enamel is provided. The zero VOC alkyd latex products will provide superior gloss and adhesion compared to acrylic latex products – just as the traditional solventborne alkyd does. However, VOC levels are not only below the solventborne alkyd, but the VOCs of the alkyd latex based formulation are well below the conventional acrylic gloss latex product. | ||
| 5.3 10:00 – 10:30 p.m. New Acrylic Hybrid Polymers for Low VOC Coatings with a Step Forward in Application Properties Versus Conventional Acrylics Rosemarie Lauer*, Anne Koller, Rohm and Haas Company Despite tightening VOC regulations, solvent based alkyds remain popular in Europe due to their exceptional open time, flow and leveling and high gloss potential. They have deficiencies, however, including relatively poor durability, film yellowing, unpleasant odor and an unfavorable environmental, health and safety profile. Here we present an alternative to solvent alkyds, a new technology platform featuring a waterborne acrylic hybrid polymer dispersion suitable for European low VOC decorative coating applications. This waterborne technology provides a much sought-after balance of application and dry film properties. High gloss capability along with excellent open time, flow and leveling, re-brush and re-coat properties are achieved through polymer design of the hybrids with an alkyd-like rheology. The applied paint stays liquid for a longer period of time and the coalescence is delayed as a result of its specific design. In addition, the technology maintains the desirable dry film properties of pure acrylic systems. Hardness is enhanced through ambient cross-linking and yellowing properties are much closer to a pure acrylic than an alkyd. The technology is suitable for high gloss, semi-gloss and satin paints. This paper focuses primarily on the open time and yellowing data for the new acrylic hybrid technology. 10:30 – 11:00 p.m. Networking: Refreshments & Coffee Break | ||
| 5.4 11:00 – 11:30 a.m. Low VOC Architectural Paints, Modified Hyperbranched Resins, a Solution in Performance Petri Mast*, Wim Grisnich, Philip Davies, Hans Hendriks, Fokelien Koldijk, Aad Lansbergen, Bart Reuvers, Stefan Willems, DSM NeoResins +, The Netherlands With the continuous trend towards stricter VOC legislation for decorative paints, it is clear that paints based on conventional solventborne alkyd resins will come under increased regulatory restriction. In this presentation a novel type of resin – modified hyperbranched resins – will be highlighted. The paper describes a comparative study of the basic drying properties of an oxidative drying architectural paint based on such a novel resin. Two new techniques were specially developed to gain insight into the processes underlying the characteristics on which decorative paints are being judged, being (i) an indentation technique and (ii) the usage of dynamic mechanical thermal analysis. Using these techniques, information is gathered on (1) the rate of autoxidation as a function of distance from the film surface film and (2) the specific impact of the autoxidation on either the cross-link density or the glass transition temperature. | ||
| 5.5 11:30 a.m. – 12:00 p.m. Improvement on Residual Monomers and Yellowing of Water Based Polymers by Use of Novel Reducing Agents Uwe Robben, Brüggemann Chemical, Germany Part of the main challenges for the production and application of water based polymers are residual monomer levels as well as yellowing of the polymer. Redox initiator systems are well known to be used in main- and post-polymerization applications to lower residual monomer levels. More demanding legal restrictions and market requirements force producers to constantly improve processes and products. The new sulfinic acid derivatives are known in the market for their formaldehyde-free and non-yellowing properties as compared to sodium formaldehyde sulfoxylate and ascorbic acid. In addition, R&D results over the last years show significant performance advantages of the new reducing agents with regard to lower residual monomer levels, broader range of applicable oxidizing agents, higher reactivity or prevention of polymer yellowing. The presentation will summarize R&D work and results for several applications. | ||
| 5.6 12:00 – 12:30 p.m. A New Class of Nonionic Rheology Modifiers for Waterborne Applications Based on Controlled Free Radical Polymerization Steffen Onclin*, Junichi Tanabe, Ernst Eckstein, Johan Bieleman, Frank Pirrung Additives based on controlled free radical polymerization are becoming a well-established group of products. Especially in the area of pigment dispersion the control over polymer architecture has led to new commercial products with superior performance when compared to conventional dispersants. In this contribution we present our recent efforts to extend this promising type of polymerization to the area of rheology modifiers for waterborne applications. We present for the first time purely acrylic, nonionic rheology modifiers, which are prepared via nitroxide mediated polymerization. This polymerization technology enables us to prepare polymer architectures that were previously not accessible because of technical difficulties or too high costs. Key is the ability to prepare polymers with a narrow molecular weight distribution, which leads to favorable rheology and thus allows polymerization and handling at high active contents. In this way better defined products are obtained, which leads to better predictable and controllable rheological behavior in aqueous systems. In the paper we will present prototypes of this new class of nonionic rheology modifiers that are close to commercial reality and compare their application behavior to standard waterborne rheology modifiers in architectural paints. | ||
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