Tailor Made Polyester Polyurethane Elastomers for Shoe Soling
J. Schwab, G.C. Bagaglio, J.M. Bentley, A. Christfreund- Organic Chemistry
- Polymers and Plastics
The production of shoe soles using cellular polyurethane elastomers on an industrial scale has been in progress for almost 20 years. Now, polyurethane shoe-soling systems are used not only for house and town shoes but also for work and safety boots as well as sport and leisure shoes. With the development of dual-density technology a large number of polyurethane soling systems are offered today.
Further progress depends on improvements to processability and certain properties. This publication gives details of those in polyester-based systems.
Developments reported in this paper include:
• a new prepolymer, PBA 2224, with improved resistance to freezing
• a new range of polyester polyols with improved storage stability that remain processable for more than 6 days under machine recirculation conditions at 45°C
• a new range of polyesters that allows greater mixing ratio latitude
• special, tailor-made polyesters and prepolymers optimised for special applications such as systems with improved
– humid-ageing resistance
– flexlife at low temperatures
– light stability – particularly of white-coloured shoe-soling systems
Such developments have led to an improved robustness in processing which, the authors postulate, should lead to an increase in market demand for polyurethanes as shoe-soling materials.