摘要:
Disclosed are polymers and copolymers of CH.sub.2 .dbd.CHR alpha olefins where R is hydrogen or a 1-6 carbon atom alkyl radical, containing in the chain from 0.1 to 40 mole % of monomeric units ##STR1## where X is selected from the group consisting of (CH.sub.2).sub.r CH.sub.2 CH.sub.2 Y ##STR2## where r=0-10, Y is a halogen atom, R.sup.1 is a hydrocarbon radical with 1-18 carbon atoms.
摘要:
Essentially syndiotactic crystalline copolymers of propylene with minor proportions of 1-butene, endowed with good mechanical properties, lowered melting point and limited solubility in xylene at 25.degree. C. and the process for their preparation by polymerizing mixtures of propylene with 1-butene, by using catalysts obtained form stereorigid and chiral zirconium and hafnium compounds and from polymethylalumoxane compounds.
摘要:
A process for continuously producing an elastomeric composition includes providing at least one extruder, metering and feeding at least one elastomer, at least one filler, and ingredients different from elastomers and fillers into the at least one extruder, mixing and dispersing the at least one filler and the ingredients different from elastomers and fillers into the at least one elastomer using the at least one extruder, and extruding a resulting elastomeric composition. The at least one extruder includes the housing and at least one screw rotatably mounted in the housing. The housing includes at least one feed opening and a discharge opening. At least one of the ingredients different from elastomers and fillers includes a subdivided product including one or more minor ingredients dispersed in at least one thermoplastic binding agent. An apparatus for continuously producing the elastomeric composition is also disclosed.
摘要:
Elastomeric ethylene/propylene or ethylene/propylene/polyene copolymers containing small amounts of one or more &agr;-olefins are prepared by a slurry process wherein the polymerization reaction is carried out in a mixture of liquid propylene and alpha-olefin.
摘要:
Novel copolymers of ethylene with propylene and optionally with minor proportions of a diene or polyene having good elastomeric properties in their uncured state. The copolymers are characterized by a structure in which the propylene is partially present in the form of short isotactic sequences. Tension set values (200%) of less than 15 are obtained by when the ethylene/propylene ratio has specific values and the intrinsic viscosity values are higher than 3.
摘要:
Amorphous copolymers of ethylene with .alpha.-olefins and optionally minor amounts of polyenes are disclosed, having the following characteristics:(A) the % by mole content of .alpha.-olefin in the copolymer (%.alpha.) and the ratio between the molar amount of .alpha.-olefin diads and the molar content of .alpha.-olefin in the copolymer (.alpha..alpha./.alpha.) satisfy the following relationship:(%.alpha.)-250(.alpha..alpha./.alpha.).gtoreq.10(B) less than 2% of the CH.sub.2 groups in the polymeric chain are in sequences (CH.sub.2).sub.n, wherein n is an even number.These copolymers are obtainable by operating in the presence of particular metallocene-based catalysts having two fluorenyl groups joined together through a bridging group.
摘要:
A process for continuously producing an elastomeric composition includes metering and feeding at least one elastomer and at least one filler into at least one extruder, mixing and dispersing the at least one filler into the at least one elastomer using the at least one extruder, and passing the composition that results through at least one static mixer. An apparatus for continuously producing the composition includes at least one twin-screw extruder, at least one metering device, and at least one static mixer. The at least one extruder includes a housing and two screws rotatably mounted in the housing. The housing includes at least one feed opening and a discharge opening. The at least one metering device meters and feeds at least one elastomer and at least one filler into the at least one extruder. The composition discharged from the discharge opening passes through the at least one static mixer.
摘要:
A process for the preparation of amorphous copolymers of ethylene with &agr;-olefins and optionally minor amounts of polyenes are disclosed, which have the following characteristics: (A) the % by mole content of &agr;-olefin in the copolymer (%&agr;) and the ratio between the molar amount of &agr;-olefin diads and the molar content of &agr;-olefin in the copolymer (&agr;&agr;/&agr;) satisfy the following relationship: (%&agr;)−250 (&agr;&agr;/&agr;)≧10 (B) less than 2% of the CH2 groups in the polymeric chain are in sequences (CH2)n, wherein n is an even number. These copolymers are obtained by operating in the presence of particular metallocene-based catalysts having two fluorenyl groups joined together through a bridging group.
摘要:
Elastomeric ethylene/propylene or ethylene/propylene/-polyene copolymers containing small amounts of one or more .alpha.-olefins are prepared by a slurry process wherein the polymerization reaction is carried out in a mixture of liquid propylene and alpha-olefin. Problems due to fouling phenomena in the reactor are avoided.
摘要:
A process for continuously producing an elastomeric composition includes providing at least one extruder, metering and feeding at least one elastomer, at least one filler, and ingredients different from elastomers and fillers into the at least one extruder, mixing and dispersing the at least one filler and the ingredients different from elastomers and fillers into the at least one elastomer using the at least one extruder, and extruding a resulting elastomeric composition. The at least one extruder includes the housing and at least one screw rotatably mounted in the housing. The housing includes at least one feed opening and a discharge opening. At least one of the ingredients different from elastomers and fillers includes a subdivided product including one or more minor ingredients dispersed in at least one thermoplastic binding agent. An apparatus for continuously producing the elastomeric composition is also disclosed.