| 摘要 |
Amorphous polyolefins include units from acyclic mono-olefins, particularly ethylene, and units derived norbornene type olefins including units of formula (I), where: n1 is 0, 1 or 2, n2 is 0 or 1 and n1 + n2 > 0; n3 is 0 or from 1 to 4; n4 is 0 or from 1 to 4; R<1>, R<2> and R<3> are each hydrogen, halogen, alkyl, cycloalkyl, aralkyl, alkaryl or aryl; the ring group A<1> is 1,2-cyclohexylene or a 1,2-phenylene which may be unsubstituted or substituted with halogen, alkyl or aryl and may have further 1,2-cyclohexylene or 1,2-phenylene fused to it. The polymers can be made by polymerisation of the monomers under Ziegler-Natta catalysis. They are amorphous and transparent having high Tg's and are useful in optical components such as optical discs. |
