Radiation Curable Low Stress Relaxation Elastomeric Materials
Published November 4, 2008
A melt-blended radiation-curable material has been issued a patent. It comprises about 20-80 weight percent of a thermoplastic elastomer (TPE), which is a block copolymer with at least one hard block comprising vinylarenes and at least one soft block comprising dienes. The material also includes about 5-60 eight percent of a processing oil; and about 5-60 weight percent of a macro photoinitiator having a number average molecular weight of from about 5000 to about 300,000. The macro photoinitiator is selected from a group and, after curing, the material has a stress relaxation of less than about 20% after 200% elongation at room temperature and a stress relaxation of less than about 45% after about 10 hours at 100°F and 50% elongation.