CREATING TOMORROW’S SOLUTIONS REPRINT I APCJ I August 2016 LOw odour, less emissions, high performance DISPERSIONS Salvia Omar, Jasmine Lim, Wack...
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REPRINT I APCJ I August 2016

LOw odour, less emissions, high performance


Salvia Omar, Jasmine Lim, Wacker Chemicals South Asia and Dr Markus Busold, Wacker Chemie AG discuss VAE-based dispersions for decorative interior paints with low environmental impact

Low odour, less emissions, high performance


Figure 1. Comparison of opacity between Vinnapas EP 3360 ULS and a commercial styreneacrylics based on different PVC levels in a low-VOC interior white paint (contrast ratio in %)

inyl acetate-ethylene copolymer (VAE) dispersions allow the formulation of highperformance interior paints with reduced emissions. Taking into account regional climatic conditions, raw materials and product standards, binders, such as the VAE dispersion Vinnapas® EP 3360 ULS can enhance the performance of coatings, while at the same time keeping with the trend toward lower environmental impact in South East Asia. Globally, building activity is constantly on the rise. This is particularly true in the Asia Pacific region, which is seeing economic growth and greater wealth, coupled with rising populations – resulting in greater urbanisation, growing infrastructure investment and increased residential building activities. Today’s coatings and construction industries also set high standards for products, which must offer high quality and performance, while at the same time being cost- and energyefficient, easy to process and complying with environmental and safety standards. Hence, the choice of binders plays a key role, as they determine the essential performance and processing properties of building materials: the binder defines a coating’s scrub resistance, touch-up properties and durability, as well as its suitability for formulating low-odour coatings with reduced emissions.

nnBENEFITS OF VAE TECHNOLOGY VAE dispersions are copolymers produced by the pressure emulsion polymerisation of the

Contrast Ratio (%)

97.8 97

95.4 95.4



PVC 45%

Vinnapas® EP 3360 ULS

PVC 55%

PVC 85%

Commercial Styrene Acrylic (5% organic solvent added)

44 APCJ • August 2016

hard, polar monomer vinyl acetate and the soft, hydrophobic monomer ethylene. The resulting copolymer dispersions feature all the benefits of the homopolymer in terms of strength and heat resistance, while also offering better adhesion and coalescence properties. Ethylene further functions as an optimum internal plasticiser for vinyl acetate polymer emulsions, imparting permanent flexibility to VAE polymers. Thus, since VAE polymers do not require an external plasticiser, they are ideal for the formulation of low-VOC (volatile organic compounds) paints. When polymerised with vinyl acetate, ethylene is more efficient than other co-monomers at reducing the glass transition temperature (Tg) and minimum film forming temperature (MFFT). VAE copolymers, thus, exhibit inherently good film forming properties, which is one reason why these dispersions are becoming the industry standard in low-odour interior paints. VAE copolymers further offer improved low-temperature coalescence, which provides better low-temperature touch-up properties. They can also provide significant improvements in mud cracking, while reducing the overall formulated cost of the paint. Additionally, VAE dispersions feature high binding power and good rheological behaviour, as well as excellent applicability and workability.


To meet the demands for high-quality, yet ecofriendly coatings in South East Asia, Wacker has developed the VAE dispersion Vinnapas EP 3360 ULS for very-low-VOC decorative coatings with excellent performance properties in formulations using regionally available raw materials. The product is an aqueous copolymer emulsion, based on vinyl acetate and ethylene and is stabilised with colloids and surfactants. Beyond formulation advantages, the product’s higher solids content of 60% makes supply chains more efficient since fewer deliveries are needed and less silo space is required. Vinnapas EP 3360 ULS offers best-in-class performance in a variety of areas, such as high opacity, high binding power and stain resistance. Here, the VAE dispersion can outperform competing technologies, including


Commercial SA 472 cycles

Vinnapas® EP 3360 ULS 1,732 cycles

Commercial SA 10 cycles

45% PVC formulation abrasive test

Vinnapas® EP 3360 ULS 22 cycles

85% PVC formulation washability test

Figure 2. Scrub resistance comparison (according to ASTM D2486) of Vinnapas EP 3360 ULS and a styrene-acrylic emulsion in a 45% (left) and 85% (right) PVC, low-VOC interior paint formulation

Vinnapas® EP 3360 ULS

45% PVC 7D cure

Commercial SA



Figure 3. Stain resistance of Vinnapas EP 3360 ULS (left side) and a styrene-acrylic emulsion (right side) in a 45% PVC interior paint formulation

traditional and low-Tg/low-MFFT styreneacrylics for interior coatings. In lab tests at Wacker’s technical centre in Singapore, Vinnapas EP 3360 ULS was compared to a commercially available standard styrene-acrylic (SA) dispersion with a Tg of 20C in a low-VOC interior white paint, based on pigment volume concentration (PVC) levels ranging from 45 to 85%, from low-sheen to matte levels. The opacity values (see Figure 1) showed better hiding power for all PVC levels. This offers advantages in formulation costs and the possibility of reducing the number of coats in conventional application systems. Based on the American Society for Testing and Materials (ASTM) D2486, Vinnapas EP 3360 ULS was tested for its performance durability (see Figure 2). In the test, Vinnapas EP 3360 ULS displayed better abrasion resistance in the 45% PVC formulation compared to a commercially available standard SA dispersion at the same PVC level. Likewise, in the 85% PVC paint, the VAE dispersion showed better washability. Altogether, Vinnapas EP 3360 ULS offers good abrasive resistance, binding power and film integrity even without coalescing aids. Furthermore, the VAE dispersion allows for high stain resistance, which increasingly meets the need for value-added functionality. When used as a binder in a 45% PVC, low-VOC interior paint, Vinnapas EP 3360 ULS was able to reduce

or remove the hydrophilic and hydrophobic stains, as Figure 3 shows. The removal of whiteboard marker was distinctive in comparison to a commercially available standard SA dispersion. Additionally, comparing the colour acceptance properties of interior coatings formulations, based on Vinnapas EP 3360 ULS with a standard SA dispersion, it is clear that the VAE binder enables good colour acceptance and colour consistency when subjected to shear stress by means of a roller or brush (see rub-out area) – even when the base paints contain critical amounts of high-volume-usage black (PBk7, 40% solids) and blue (PB15:4, 27% solids) pigments (see Figure 4). The colour strength development also indicates a formulation cost advantage due to the adjustment of pigment/filler systems, such as titanium dioxide.


Vinnapas EP 3360 ULS enables the formulation of low-odour and very low-VOC paints (