摘要:
A solution of butyl rubber in an inert solution such as n-hexane is halogenated in a continuous process using bromine chloride vapor and high intensity mixing means for both the halogenation and subsequent neutralization steps. Adjustment of the mole ratio of bromine chloride to isoprene, where an isobutylene-isoprene butyl copolymer is used, to less than about 1.5 to 1 prevents overhalogenation and significant molecular weight loss, while the use of bromine chloride vapor results in improved process safety.The doubly halogenated product, containing both bromine and chlorine in its structure can be vulcanized in the absence of sulfur, e.g., with zinc oxide. It is particularly useful in rubber compositions where the singly halogenated product is employed, but demonstrates product performance advantages compared to both brominated butyl rubber and chlorinated butyl rubber.
摘要:
The present invention relates to novel copolymers of alpha-olefins comprised of intramolecularly heterogeneous and intermolecularly homogeneous copolymer chains.
摘要:
This invention relates to block polymers containing both crystalline and elastomeric blocks, the block copolymer having an A block and a B block. The A block is a polyethylene or an ethylene polymer optionally containing an alpha-olefin and optionally a non-conjugated diene, and is generally crystalline. The B block is an ethylene, .alpha.-olefin copolymer. Also disclosed is a process for manufacture of the block copolymers and methods for coupling the block copolymers. Coupled block copolymers are useful as thermoplastic elastomers exhibiting physical properties approaching those of crosslinked EP or EPDM elastomers, but showing thermal processability after coupling. The block copolymers of the present invention may also be used as a lubricant or fuel additive, as a plastics blend component, and as a component in hot melt adhesives.
摘要:
This invention relates to block polymers containing both crystalline and elastomeric blocks, the block copolymer having an A block and a B block. The A block is a polyethylene or an ethylene polymer optionally containing an alpha-olefin and is generally crystalline. The B block contains an ethylene, .alpha.-olefin copolymer segment and optionally contain an ethylene, .alpha.-olefin, non-conjugated diene terpolymer segment. If the B block contains a diene containing segment, the diene containing segment is furthest from the junction of the A and the B blocks. Also disclosed is a process for manufacture of the block copolymers and methods for coupling the block copolymers. Coupled block copolymers are useful as thermoplastic elastomers exhibiting physical properties approaching those of crosslinked EP or EPDM elastomers, but showing thermal processability after coupling. The block copolymers of the present invention may also be used as a lubricant or fuel additive, as a plastics blend component, in bitumen blends, as a component in hot melt adhesives and as a component of roof sheeting compounds.
摘要:
The present invention relats to novel copolymers of alpha-olefins comprised of intramolecularly heterogeneous and intermolecularly homogeneous copolymer chains.