摘要:
Film, molded articles and fibers prepared from ethylene/&agr;-olefin interpolymer compositions are disclosed. The interpolymer compositions are blends prepared by combining specified amounts of a narrow molecular weight distribution, narrow composition distribution breadth index interpolymer, and a broad molecular weight distribution, broad composition distribution breadth index interpolymer, with each blend component having a specified density, melt index and degree of branching.
摘要:
A new process of interpolymerizing ethylene interpolymer products having improved properties, such as increased onset of crystallization temperature, is disclosed. Preferably, the process comprises interpolymerizing a first homogeneous ethylene/alpha-olefin interpolymer and at least one second homogeneous ethylene/alpha-olefin interpolymer using at least two constrained geometry catalysts having different reactivities such that the first ethylene/alpha-olefin interpolymer has a narrow molecular weight distribution (NMWD) with a very high comonomer content and relatively high molecular weight and the second ethylene/alpha-olefin interpolymer has a NMWD with a low comonomer content and a molecular weight lower than that of the first interpolymer. The resultant first homogeneous interpolymer is combined with the resultant second homogeneous interpolymer in appropriate weight ratios resulting in the desired finished polymer structure. The first interpolymer and the second interpolymer can be polymerized in a single reactor or they can be polymerized in separate reactors operated in parallel or series.
摘要:
Processes for polymerizing ethylene/.alpha.-olefin interpolymer compositions are disclosed. The interpolymer compositions have a controlled composition and a controlled molecular weight distribution. The processes utilize a highly-efficient homogeneous catalyst composition in at least one reactor to produce a first interpolymer having a narrow composition distribution and a narrow molecular weight distribution, and a highly-efficient heterogeneous Ziegler catalyst in at least one other reactor. The reactors can be operated sequentially or separately, depending upon the desired product. The novel compositions have good optical properties (e.g., clarity and haze) and good physical properties (e.g., modulus, yield strength, toughness and tear). Useful products which can be formed from these compositions include film, molded articles and fiber.
摘要:
A supported catalyst composition comprising a complex of a Group 4 metal cyclopentadienyl derivative reacted with silica treated with an aluminoxane demonstrates improved reactivity, especially for incorporating long chain alpha-olefins and also shows improved resistance to catalyst poisoning. The supported catalyst composition is adapted to produce homogeneous polymers, copolymers, terpolymers, etc., for example, homogeneous polyethylene, homogeneous poly(ethylene-octene) copolymers and the like. The invention further includes the process of preparing the supported catalyst compositions and a process for preparing olefinic polymers using these catalyst compositions.
摘要:
An addition polymerization catalyst comprising a cationic complex of a Group 4 metal cyclopentadienyl derivative and an alumoxane shows improved resistance to catalyst poisons.
摘要:
A new process of interpolymerizing ethylene interpolymer products having improved properties, such as increased onset of crystallization temperature, is disclosed. Preferably, the process comprises interpolymerizing a first homogeneous ethylene/alpha-olefin interpolymer and at least one second homogeneous ethylene/alpha-olefin interpolymer using at least two constrained geometry catalysts having different reactivities such that the first ethylene/alpha-olefin interpolymer has a narrow molecular weight distribution (NMWD) with a very high comonomer content and relatively high molecular weight and the second ethylene/alpha-olefin interpolymer has a NMWD with a low comonomer content and a molecular weight lower than that of the first interpolymer. The resultant first homogeneous interpolymer is combined with the resultant second homogeneous interpolymer in appropriate weight ratios resulting in the desired finished polymer structure. The first interpolymer and the second interpolymer can be polymerized in a single reactor or they can be polymerized in separate reactors operated in parallel or series.
摘要:
A new process of interpolymerizing ethylene interpolymer products having improved properties, such as increased onset of crystallization temperature, is disclosed. Preferably, the process comprises interpolymerizing a first homogeneous ethylene/alpha-olefin interpolymer and at least one second homogeneous ethylene/alpha-olefin interpolymer using at least two constrained geometry catalysts having different reactivities such that the first ethylene/alpha-olefin interpolymer has a narrow molecular weight distribution (NMWD) with a very high comonomer content and relatively high molecular weight and the second ethylene/alpha-olefin interpolymer has a NMWD with a low comonomer content and a molecular weight lower than that of the first interpolymer. The resultant first homogeneous interpolymer is combined with the resultant second homogeneous interpolymer in appropriate weight ratios resulting in the desired finished polymer structure. The first interpolymer and the second interpolymer can be polymerized in a single reactor or they can be polymerized in separate reactors operated in parallel or series.
摘要:
Ethylene, an &agr;-olefin and, optionally, a diene monomer are polymerized in a process comprising the step of contacting (1) ethylene, (2) at least one C3-C20 aliphatic &agr;-olefin, (3) optionally, at least one C4-C20 diene, (4) a catalyst comprising (a) a metallocene complex, and (b) an activator, and (5) a solvent. The process is conducted in either a single reactor or in multiple reactors, the latter configured either in series or parallel. Solvent is removed from the polymer stream in an anhydrous, first stage solvent recovery operation such that the solids concentration of the product stream is increased by at least 100 percent. Additional solvent is removed in an anhydrous, second stage solvent recovery operation from the product of the first stage solvent recovery operation such that the solids concentration of the product stream is in excess of 65 weight percent.
摘要:
Processes for polymerizing ethylene/.alpha.-olefin interpolymer compositions are disclosed. The interpolymer compositions have a controlled composition and a controlled molecular weight distribution. The processes utilize a highly-efficient homogeneous catalyst composition in at least one reactor to produce a first interpolymer having a narrow composition distribution and a narrow molecular weight distribution, and a highly-efficient heterogeneous Ziegler catalyst in at least one other reactor. The reactors can be operated sequentially or separately, depending upon the desired product. The novel compositions have good optical properties (e.g., clarity and haze) and good physical properties (e.g., modulus, yield strength, toughness and tear). Useful products which can be formed from these compositions include film, molded articles and fiber.