Innovative Binders for Colorful Solutions in the Standard and Economy Paint Space Ana Beatriz Araujo, Luz Adriana Gómez O., Carolina Mantilla, Gary Dombrowski, Keith Alderfer, Juliana Pissardini. The Dow Chemical Company Dow Coatings Materials Business ABSTRACT The technical information used to describe the premium formulation space requires three or more specifications to adequately describe the coatings performance, while a single descriptor is sufficient for the economy paint space. In the economy paint space, a high hiding power for white and pastel bases is often the property that is desired above all others. However, when color is inserted into the equation (or added to the paint), most solutions are not designed to provide vivid color while still achieving the same performance targets as white and pastel bases. A new generation of binders was produced, using High-throughput screening, to optimize the most valued properties in this space. In order to provide a colorful solution for the consumer in both standard and economy paint formulation spaces, binders with reduced surfactant leaching, combined with outstanding scrub resistance, have been developed. The understanding of the contribution of each one of the factors evaluated, as well as the use of specific analytical methodologies to delimitate the properties to be improved, has led us to a perfect solution. The solution oriented toward delivering a great appearance of vivid colors and specifically focused on improving issues related to colorant compatibility, whitening, water sensitivity, film defects and surfactant leaching. These new binders represent a new generation of high performance products offering breakthrough performance to vibrantly tinted paint formulations. INTRODUCTION Architectural coatings are the largest segment of the coatings industry and are used on new and existing residential, commercial, institutional and industrial structures. These paints are usually distributed through a range of stores, wholesale/retail channels and are purchased for two primary customer types; professional painting contractors and the do-it-yourself (DIY) users (homeowners). (i) In markets such as North America and Europe, architectural coatings are divided into two major categories: interior and exterior. Each segment has different characteristics; exterior coatings are designed to accomplish higher performance than interior due to the fact that exterior paints are exposed to weather conditions. Most of the architectural paints in the Latin America region are commonly used for both categories, interior and exterior. In general, the primary performance requirement is hiding power, and scrub resistance is used as an indirect measurement for paint 1 P a g e
durability. As a result of this market situation, paint manufacturers play an important role as technology providers, facilitating the generation of cost/effective solutions that address the main interior/exterior properties for each quality segment. The introduction of Tinting Bases Systems almost 30 years ago lead to the possibility of offering a broad space of color in contractor and economy spaces. The demand for application of vividly colored paints exterior has significantly challenged the Latin America market for improved solutions. An architectural binder, together with a broad additives portfolio for economic and medium quality paint spaces that address segment performance requirements for market trends like colorful paints and scrub resistance at accessible prices was considered the way to innovate in spaces where cost is one of the most important variables in the equation. EXPERIMENTAL PART In order to test the potential of the new binder to deliver interior and exterior properties in the economy and contractor spaces, two formulas were evaluated. These formulas represent different segments in Latin America. The new vinyl-acrylic modified binder was tested in the following formulation systems (Figure 1) and compared to the control binder in each respective space. Formulation Properties Economy Flat Standard Application Usage Interior Interior & Exterior Binder (50.0% NV) Styrene-Acrylic/ 7.00 Vinyl-Acrylic/ 20.00 PVC (%) 80.00 65.00 Solids/Volume (%) 21.00 32.00 Solids/ Weight (%) 39.00 50.00 Density (g/cm 3 ) 1.310 1.360 Figure 1. Parameters for two different formulation spaces for Latin America The properties measured for both formulas are according to those listed in the Brazilian Regulation and measured using to the corresponding ABNT NBR Norm based on ASTM D2486 (Figure 2). For the economy space, the control binder considered was styrene-acrylic. For the Flat Standard space, the references were two well known vinyl-acrylic polymers that are widely used in this space for the north region of Latin America. 2 P a g e
Paint Quality Wet Hiding (1) Dry Hiding (2) (3) (4) Scrub Resistance Economy Standard Flat Premium 55,0 % 4,0 m 2 /L 100 cycles (3) 85,0 % 5,0 m 2 /L 40 cycles (4) 90,0 % 6,0 m 2 /L 100 cycles (4) (1) Measures the hiding power of a drawdown film immediately after its application in a leneta chart 2) Measures the hiding power of a dry film, which is the maximum applied area (m 2 ) per unit of volume (L) that presents a contrast ratio of at least 98,5% (yieldcalculationbasedondensity, contrast ratios andquantity of paint transferredto the applicationchart) (3) Measures the number of cycles needed to remove 80% of the paint in the area where the brush passes trough (with soap solution) (4) Measures the number of cycles needed to remove paint in a continuous line perpendicular to the brass shim (with abrasive paste) Figure 2. Resume of properties listed in ABNT Regulation for Architectural Coatings Quality designation. RESULTS AND DISCUSSION Results in Economy Space (80 PVC) A comparison between the new PVA (vinyl acrylic) polymer (PRIMAL NueVa ) with a benchmark of the market and a conventional Sty-Acrylic binder is presented in Figure 3. The results show a similar non-abrasive scrub resistance for the PVA polymer compared with the Sty-Acrylic samples. In addition, the influence of a coalescent with a higher vapor pressure (Dowanol PPh) than Ucar Filmer IBT also has an impact in the non-abrasive scrub resistance property. The use of Dowanol PPh appears to result in better film formation of the binder. 240 190 Non-Abrasive Scrub Resistance No. Of Cycles 140 90 40-10 Market SA #1 Ucar Filmer IBT 10% Market SA #2 Ucar Filmer IBT 10% PRIMALNueVa Ucar Filmer IBT 7% PRIMALNueVa Dowanol PPh 7% 3 P a g e Average valueof 3 trials. Bar error: 25% Media: DetergentSolution 1% Surfactant (NPE 9) ABTN NBR 15078 Figure 3. Non-Abrasive Scrub Resistance NBR 15078 The hiding properties for all the paints were comparable and related to the formulation itself. All of the paints accomplished the local regulation for an economic space.
Results in Flat Standard Formulation (65 PVC) Considering other vinyl-acrylic binders as reference, the scrub resistance for the abrasive test shows PRIMAL NueVa has better properties than any other product in the market (Figure 4). 240 190 Abrasive Scrub Resistance Cycles No. 140 90 40-10 ROVACE 661 ROVACE 9900 PRIMAL NueVa Media value of 3 data. Bar error = 1 ( 15%) Figure 4. Abrasive Scrub Resistance Results for 65 PVC Formula according to the ASTM D2486. The non-abrasive scrub resistance in this formulation space for PRIMAL NueVa is higher than 10,000 cycles and similar to the benchmark in the market, Rovace 9900 (Figure 5). Non-Abrasive Scrub Resistance Cycles No. 18000 16000 14000 12000 10000 8000 6000 4000 2000 0 ROVACE 661 ROVACE 9900 PRIMAL NueVa Media value of 5 data. Bar error = 1 ( 30%) Figure 5. Comparison of Non Abrasive Scrub Resistance according to ASTM D2486 using detergent solution 4 P a g e
Surfactant Leaching for Flat Standard Formulation. Surfactant leaching is a phenomenon where stains (glossy, tan or brown) appear over exterior latex paint when certain environmental conditions exist, mainly high humidity. The phenomenon is more apparent for dark, deep and accent colors. There are multiple factors that can lead us to have a more severe surfactant leaching. Binder choice can be one important factor to reduce the appearance of surfactant leaching. (ii) In Figure 6, the results for surfactant leaching are shown using several vinyl-acrylic binders. The two PRIMAL NueVa binders perform excellent and dramatically reduce the surfactant leaching stain in the application. Figure 6. Surfactant leaching test for Accent base 100 g/l colorants C, R, F, T Colortrend 888 C; Yellow Oxide, R; Organic Red F; Red Oxide, T; Medium Yellow CONCLUSIONS The PRIMAL NueVa fully achieve the property specifications required according to the Brazilian Regulations in the formulation spaces under which it was studied. The improvement in surfactant leaching in the flat standard space offers a new way to include innovation to the medium and economy segments. The new product offered, PRIMAL NueVa also were designed to be APEO free in order to achieve DOW s sustainability goals. 5 P a g e
ACKNOWLEDGMENTS To Dow s experts in Collegeville for always transform their knowledge into real products and solutions. To Luz Adriana Gómez for all the support and valuable contributions always keeping our Queretaro team focus on what is important to the success. To all the DOW Team involve in NueVa development, together we can go further. BIBLIOGRAPHIC REFERENCES i. Eric Linak with Akihiro Kishi,CEH Marketing Research Report VINYL SURFACE COATINGS, August 2010. ii. Surfactant Leaching.Exterior Latex Paint PQI Institute. Trademark of The Dow Chemical Company ( Dow ) or an affiliated company of Dow. 6 P a g e