High flow, hydrogenated styrene-butadiene-styrene block copolymers and applications
View Patent ↗The invention relates to unique applications for the novel high melt flow, low viscosity, selectively hydrogenated styrene-butadiene-styrene (hSBS) or selectively hydrogenated controlled distribution styrene-butadiene/styrene-styrene (hSBSS) block copolymers, wherein the melt flow rate of said block copolymer is at least 100 g/10 min at 230° C. under 2.16 kg mass according to ASTM D1238. These block copolymers are novel and have the highest melt flow rate of any styrenic block copolymer also possessing high strength and elasticity. It has applications that prior to the present invention were not normally possible due to the normal low melt flow rate of styrenic block copolymers. The present invention also encompasses various fields of use such as a fiberglass hSBS or hSBSS reinforced mat, low viscosity hSBS or hSBSS coatings for industrial uses, hot melt adhesives prepared from hSBS or hSBSS blended with polyalpha-olefins, and elastic film, fiber, and nonwoven constructions using hSBS or hSBSS.
1. A slush molded, rotational molded, injection molded, or calendared article comprising styrenic block copolymer having a melt flow rate greater than 100 g/10 min at 230° C., and 2.16 kg mass, said styrenic block copolymer being hydrogenated styrene-butadiene-styrene or selectively hydrogenated controlled distribution styrene-butadiene/styrene-styrene wherein said styrenic block copolymer has a minimum peak molecular weight of 45,000; a polystyrene content of between about 18 to about 33%, a vinyl content of about 65 to 80%, a coupling efficiency of about 60 to about 97%, and said butadiene is hydrogenated at least 90%.
2. The molded or calendared article of claim 1 , containing an additional component of high flow polyolefin having a melt flow rate >40 g/10 min at 210° C. and 2.16 kg mass, polyisobutylene, polybutene, thermoplastic polyurethane, thermoplastic copolyester, oil, styrenic block copolymer with melt flow rate <100 g/10 min, and/or mid-block or end block resins.