Optimization of Binder Content in Paints to Partially Substitute Acrylate Content – Investigation of Binder Properties Through a Functional and Environmental Perspective

Abstract

The acrylate binder in the Surface Protection paint produced by Sioo Wood Protection, is suspected to be less environmentally friendly than the other binders in the paint. Therefore, a substitution of the binder with a more environmentally friendly alternative is of interest to the company. However, simultaneously, the company wants to retain desirable paint properties. To investigate alternatives, six different binders (named, B1-B6), were analyzed. The binders contained either silane and polymeric siloxane or fully reacted siloxane. Further, the binders were tested in paint matrices containing solely one binder (named, monobinder paints) or in paint matrices with several binders (named, polybinder paints). For the polybinder paints, two different ratios of acrylate content were tested, either a ratio where the investigated binder partially replaced the acrylate content or completely replaced it. In order to compare the properties, reference monobinder- and polybinder paints with the acrylate binder, and without any of the investigated binders, were formulated. To evaluate if the binders were suitable for the Surface Protection paint, the functional properties and the environmental impact of monobinder- and polybinder paints were investigated. Test methods to evaluate the functional properties were: measurements of viscosity, solid content, color and gloss, cross hatch testing, stability tests, texture of paint coating, weathering test and accelerated weathering test. The environmental impact of the binders was limited to the manufacture and transportation of the binder i.e. step A1 and A2 in a Life Cycle Analysis (LCA). Testing of monobinder paints showed best results for binder B2, B5 and B6, all containing fully reacted siloxanes. Hence, these binder were selected for the production of polybinder paints. Testing of the polybinder paints showed best results when the acrylate content was partially substituted by binder B2, and when the acrylate content was completely substituted by binder B6. Binder B5, on the other hand, gave poor results, both when partially or completely replacing the acrylate content. The environmental impact was generally the lowest for paints with binder B6. However, only if the binder was transported by ship. The overall results, from both a functional and environmental perspective, suggest that binder B6 is the most preferable choice to substitute the acrylate binder and to obtain desirable properties with low environmental impact.