New Trend in Color Stability: Aliphatic Polyurethane Binder

Ravago Petrokimya Üretim A.Ş. produces thermoplastic elastomers, engineering plastics, silicone elastomers, EPS, thermoplastic polyurethane and polyurethane systems within its portfolio. Tekpol Polyurethane System House, a division of Ravago Petrokimya Üretim A.Ş., offers rigid polyurethane systems, discontinuous panel (DCP) polyurethane systems, continuous panel (CP) polyurethane systems, spray polyurethane systems, flexible polyurethane systems, molded flexible polyurethane systems, molded foam systems, integral skin systems, viscoelastics, semi-rigid products, RIM, filter systems, footwear and sole systems, C.A.S.E (coatings, adhesives, elastomers) and polyurethane systems. Under the Tekpol umbrella of Ravago Petrokimya Üretim A.Ş., development work has been completed on a new single-component, moisture-cured, UV-resistant, non-yellowing aliphatic polyurethane binder, and the product has been launched to the market. Our products are available in two types depending on application areas, with product codes as follows: • Evonat C 102 • Evonat C 150 Aromatic-based polyurethane binders cause color change and yellowing on application surfaces even in very short periods, which prompted customer demand for a UV-resistant, non-yellowing product to eliminate this disadvantage. Because aliphatic isocyanate has no aromatic groups in its structure, the resulting final product has been given color stability and superior adhesion performance properties. Beyond UV resistance, the most important characteristic of aliphatic binder products, other notable properties include: • 100% solids, solvent-free, • Flexible, • Transparent, • Easy to apply, • Excellent bond line integrity. Aliphatic binder products are primarily used in adhesion of rubber-derived products on walkways, playgrounds, sports field surfaces, and park and garden ground coatings.

Figure 1. Applications using Evonat C 102

In playground applications, small granules of recycled truck tire products, referred to as SBR rubber, are applied to the ground with aromatic binder at a thickness determined by project requirements. Subsequently, EPDM granules—which are available in different colors and sizes and have a softer structure—are applied over the SBR granule surface with aliphatic binder at a specific rate using a spreader machine (Finisher) or by hand application.

Figure 2. Evonat C 102 EPDM ground application

Laboratory test results for our aliphatic, single-component Evonat C 102 product used as binder in these applications are as follows:

Table 1. Technical and mechanical test data for Evonat C 102 product

In addition to this product, upon customer request, we have developed Evonat C 150, an aliphatic rigid binder product for binding decorative quartz stones with a harder structure. Laboratory test data for this product are as follows:

Table 2. Test results for Evonat C 150 product

Figure 3. Aliphatic stone binder Evonat C 150 product

Evonat C 102 was subjected to accelerated aging testing in a UV aging cabinet according to ISO 4892-3 test standard, and no color change was observed in the product after testing. The UV color change curve for the test is as follows:

Graph 1. UV Color Change Curve

Figure 4. Color change in aromatic binder product after UV exposure

Figure 5. UV aging cabinet

Figure 6. Aliphatic binder product after UV exposure

In light of all this information, our aliphatic binder products have met customer expectations both due to the absence of color change and yellowing on applied surfaces and because of their physical and mechanical properties. Elif Öz Çetin R&D Engineer Ravago Group