EXPANDABLE THERMOPLASTIC GEL COMPOSITION

摘要

The invention concerns an expandable thermoplastic gel composition comprising (a) a block copolymer comprising at least one polymer block A derived from a monovinyl aromatic compound and at least one polymer block B derived from a conjugated diene; (b) a liquid component selected from the group consisting of extending oils, plasticizers and solvents which are compatible with the aforementioned block copolymer (a); (c) heat expandable thermoplastic particles encapsulating heat expandable gas or liquefied gas; and (d) optionally a photo-initiator,

characterized in that the block copolymer (a) is a block copolymer that may be cross-linked by exposure to radiation and that has a monovinyl aromatic compound content from 7 to 35% by weight based on total polymer, a total apparent molecular weight of from 50 to 1,500 kg/mole and a vinyl content in block B of from 10 to 80 mole%, wherein the B blocks have optionally been hydrogenated up to a degree that at least 25% of the original ethylenical unsaturation is left. According to another aspect of the present invention, there are provided two processes for producing the expanded flexible gel composition. The invention also relates to the use of an expanded flexible gel composition in automotive appliances, but also in applications such as cable filling, re-enterable sealing of electrical connections, vibration damping, pressure relief, toys, cushioning, grips, therapeutic and orthopaedic devices, and even flexographic printing plates.