TWI Industrial Member Report Summary 1007/2011
By A Taylor and L Barrett
There is an ever-increasing pressure on the performance of coatings from a number of sources. These include legislative changes which are forcing the continued reduction of volatile organic compounds (VOCs) driving coating manufacturers to use water as a diluent rather than solvents. End users are also looking for improved performance and reduced costs. They also have concerns that the switch to water-borne systems, from solvent-borne, will have effects on coating performance, for example the reduction of long term durability.
The development of formulations that pass the acceptance criteria of the coating applicators and end users, now and in the future, is a key driver in the industry. New coating systems and new coating raw materials offer opportunities to overcome some of the obstacles faced by traditional products. Sol-gel technology has long been used to incorporate some inorganic material into organic resins to enhance performance (Schmidt, 1985). Silsesquioxanes are new chemical compounds that offer the opportunity to increase the amount of inorganic material incorporated
TWI has developed a two stage sol-gel based method of silsesquioxane manufacture called Vitolane® technology. This fabrication methodology has been developed at laboratory scale and has recently been scaled up to the multi-kilogram level by TWI and Industrial Member Thomas Swan in partnership.
This report consists of two main parts. The first provides the industrial context for the liquid coating market, the background for the incorporation of inorganic materials into organic coatings and gives an overview on silsesquioxanes as new inorganic-organic hybrids. The second part of the report describes the preliminary evaluation of the chemical characteristics of a number of methacrylate silsesquioxanes produced using Vitolane technology, including a comparison between samples produced in the laboratory and at pilot scale manufacture.
- Provide an overview of the liquid coatings market identifying the key drivers and opportunities for the incorporation of novel additives such as silsesquioxanes.
- Identify and review the dominant approaches in the synthesis of silsesquioxanes.
- Determine the physical properties of methacrylate silsesquioxane resins produced using the Vitolane method.
- Undertake preliminary molecular structural analysis of the methacrylate silsesquioxane resins manufactured using the Vitolane method to provide:
- Evaluation of the molecular weight distribution.
- Qualitative assessment of the degree of condensation.
- Assessment of the degree of hydrolysis and detection any residual unreacted alkoxy groups.
- Comparison of resins produced at laboratory and pilot scales.
- Identification of potential routes for optimisation.