摘要:
A metallocene compound having the general formula: CpAXMQ1Q2Cp′A′X′M′Q1′Q2′ wherein Cp and Cp′ are each independently a substituted or unsubstituted cyclopentadienyl moiety; M and M′ are each independently a metal chosen from Group IV B transition metals and vanadium, and coordinate to Cp and Cp′ respectively; X and X′ are each independently a substituted or unsubstituted Group VA or VIA heteroatom and coordinate to M and M′ respectively; A and A′ are bridging groups between Cp and X and between Cp′ and X′ respectively and are independently chosen from —SiR′2—O—SiR′2—, —SinR′m—, —CnR′m— and —CR′2—SiR′2—CR′2—SiR′2—, in which each R′ is independently H or hydrocarbyl having 1 to 20 carbon atoms, n is an integer in the range 1 to 4 and m=2n; each Q1, Q2 and Q1′ and Q2′ is independently a coordinating group which is hydrogen, halogen or hydrocarbyl having 1 to 20 carbon atoms and each of Q1 and Q1′ is coordinated to both M and M′.
摘要:
A method for the copolymerization of ethylene and a C3+ olefin in a loop reactor and polymers formed therefrom are described herein. The method generally includes introducing an ethylene monomer, a C3+ olefin and a diluent carrier liquid into a loop reactor. A catalyst system can be supplied to said loop reactor. The diluent liquid, ethylene monomer, and C3+ olefin can be circulated through said loop reactor, while copolymerizing said ethylene and C3+ olefin in the presence of said catalyst system to produce a slurry. The slurry can be diverted into a settling leg, and sequentially discharged therefrom and withdrawn from said loop reactor. An ethylene monomer co-feed can be introduced into said loop reactor at spaced locations downstream of the ethylene and diluent. The ethylene co-feed can be introduced in an amount effective to reduce the variation in the ratio of ethylene and C3+ olefin.
摘要:
A process for purifying an olefin-containing hydrocarbon feedstock comprising the steps of: (a) passing the said hydrocarbon feedstock in the presence of hydrogen over a first catalyst bed material comprising nickel deposited on a support material wherein said nickel is present as both nickel oxide and metallic nickel (b) recovering the feedstock having a substantially reduced acetylenics (in particular methylacetylene) and allenes (in particular propadiene) content.
摘要:
Process to kill a continuous catalyzed olefin liquid phase polymerization in which the catalyst is a Ziegler-Natta or a metallocene catalyst, wherein, a predetermined amount of killing agent is injected into the reactor during at least twice the cycle time of the reactor.
摘要:
This invention discloses caps and closures for carbonated drinks produced by injection moulding or by compression moulding with a bimodal high density polyethylene (HDPE) resin.
摘要:
The invention discloses a metallocene catalysed slurry polymerisation process s of ethylene in the presence of a low concentration of scavenger. This allows improving the anti-sheeting of the reactor during the polymerisation process.
摘要:
A polyethylene resin comprising a blend of from 35 to 49 wt % of a first polyethylene fraction of high molecular weight and 51 to 65 wt % of a second polyethylene fraction of low molecular weight, the first polyethylene fraction comprising a linear low density polyethylene having a density of up to 0.928 g/cm3, and an HLMI of less than 0.6 g/10 min and the second polyethylene fraction comprising a high density polyethylene having a density of at least 0.969 g/cm3, and an MI2 of greater than 100 g/10 min, and the polyethylene resin, having a density of greater than 0.951 g/cm3 and an HLMI of from 1 to 100 g/10 min.
摘要翻译:一种聚乙烯树脂,其包含35至49重量%的高分子量第一聚乙烯部分和51至65重量%的低分子量第二聚乙烯部分的共混物,所述第一聚乙烯部分包含线性低密度聚乙烯,其具有 密度高达0.928g / cm 3,HLMI小于0.6g / 10min,第二聚乙烯级分包含密度为至少0.969g / cm 2的高密度聚乙烯 > 3 SUP>和大于100g / 10分钟的MI 2,和密度大于0.951g / cm 3的聚乙烯树脂, HLMI为1至100g / 10min。
摘要:
The present invention relates to an apparatus and process for polymerizing olefins. One embodiment comprises polymerizing at least one monomer in a first loop reactor in the presence of a catalyst to produce a first polyolefin fraction. A portion of the first polyolefin fraction is transferred to a second loop reactor, connected in series with the first loop reactor. The process further comprises polymerizing in the second loop reactor at least one monomer in the presence of a catalyst to produce a second polyolefin fraction in addition to the first polyolefin fraction. The combination of the first and second polyolefin fractions can produce a polymer resin fluff having bimodal molecular weight distribution.