Abstract:
The present invention relates to fibers comprising at least 98 wt% of a propylene polymer having, in particular, a specific molecular weight distribution M w /M n and xylene solubles content. The present invention also relates to nonwovens, laminates and composites comprising such fibers. Furthermore, the present invention relates to a process for producing such fibers, nonwovens, laminates and composites.
Abstract:
A multimodal linear low density polyethylene polymer having a final density of 900 to 940 kg/m 3 , and containing at least one α-olefin comonomer in addition to ethylene comprising: (A) 30 to 60 wt% of a lower molecular weight component being an ethylene homopolymer or a copolymer of ethylene and at least one α-olefin; and (B) 70 to 40 wt% of a higher molecular weight component being a copolymer of ethylene and at least one α-olefin, said α-olefin being the same or different from any α-olefin used in component (A) but with the proviso that both components (A) and (B) are not polymers of ethylene and butene alone; wherein the multimodal LLDPE has a dart drop of at least 700 g; and wherein components (A) and (B) are obtainable using a Ziegler-Natta catalyst.
Abstract:
The present invention discloses a process for preparing polyethylene resins in a double loop reactor wherein the catalyst system comprises a bis-tetrahydroindenyl and a bis-indenyl catalyst component deposited on the same support. It also discloses the polyethylene resins obtained by the process and their use to prepare films having a good compromise of haze, processing and mechanical properties.
Abstract:
A process for the slurry polymerization of one or more α-olefins in a sequence of at least two loop reactors interconnected by means of a transfer line, the transfer of polymer from a first loop reactor to a second loop reactor comprising the steps: i) establishing a recycle of polymer slurry to the second loop reactor by means of said transfer line, whereby a fraction of polymer slurry S1 withdrawn from said second loop reactor is continuously recycled back to it; ii) discharging a fraction of polymer slurry produced in the first loop reactor into a discharge line connected to said transfer line;
Abstract:
A process to prepare a multimodal polyethylene with controlled LCB distribution is disclosed. In the first stage, ethylene is polymerized in the presence of a Ziegler catalyst that results in a homopolyethylene component having a higher LCB concentration. In the second stage, ethylene is copolymerized with a 1-olefin in the presence of the Ziegler catalyst and a lower concentration of hydrogen resulting in a copolymer component with a lower LCB concentration. The homopolyethylene component and the copolymer component are combined to form a novel multimodal polyethylene.
Abstract:
A bimodal polyethylene having a high density ranging from about 0.955 to about 0.959 g/cc, an improved environmental stress cracking resistance (ESCR) of from about 400 to about 2500 hours, and an improved 0.4% flesxural modulus of from about 180,000 to about 260,000 psi (1,200 MPa to about 1,800 MPa) may be formed using a Ziegler-Natta polymerization catalyst using two reactors in series. The bimodal polyethylene may have a high load melt index (HLMI) of from about 2 and about 30 dg/min and may be optionally made with a small amount of alpha-olefinic comonomer in the second reactor. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).
Abstract:
The instant invention is a high-density polyethylene composition, method of producing the same, injection molded articles made therefrom, and method of making such articles. The high-density polyethylene composition of the instant invention includes a first component, and a second component. The first component is a high molecular weight ethylene alpha-olefin copolymer having a density in the range of 0.920 to 0.946 g/cm3, and a melt index (I21.6) in the range of 1 to 15 g/10 minutes. The second component is a low molecular weight ethylene polymer having a density in the range of 0.965 to 0.980 g/cm3, and a melt index (I2) in the range of 30 to 1500 g/10 minutes. The high-density polyethylene composition has a melt index (I2) of at least 1, a density in the range of 0.950 to 0.960 g/cm3. The method of producing a high-density polyethylene composition includes the following steps: (1) introducing ethylene, and one or more alpha-olefin comonomers into a first reactor; (2) (co)polymerizing the ethylene in the presence of one or more alpha-olefin comonomers in the first reactor thereby producing a first component, wherein the first component being a high molecular weight ethylene alpha-olefin copolymer having a density in the range of 0.920 to 0.946 g/cm3, and a melt index (I21.6) in the range of 1 to 15 g/10 minutes; (3) introducing the first component and additional ethylene into a second reactor; (4) polymerizing the additional ethylene in the second reactor thereby producing a second component, wherein the second component being a low molecular weight ethylene polymer having a density in the range of 0.965 to 0.980 g/cm3, and a melt index (I2) in the range of 30 to 1500 g/10 minutes; and (5) thereby producing the high-density polyethylene composition, wherein the high-density polyethylene composition having a melt index (I2) of at least 1, a density in the range of 0.950 to 0.960 g/cm3. The injection molded articles according to instant invention comprise the above-described inventive high-density polyethylene composition, and such articles are made via injection molding.
Abstract:
A process for the production of aqueous binder latices by multistage emulsion polymerization in the aqueous phase, comprising the successive steps: 1) free-radical polymerization of a monomer mixture A comprising acidic monomers in a proportion corresponding to an acid value of 10 to 100 mg of KOH/g and olefinically polyunsaturated monomers in a proportion of 0.5 to 5 wt%, 2) neutralization of acid groups of the polymer formed in process step 1) and 3) free-radical polymerization of at least one monomer mixture B comprising acidic monomers in a proportion corresponding to an acid value of mixture(s) B of 0 to below 5 mg of KOH/g, hydroxyl-functional monomers in a proportion corresponding to a hydroxyl value of mixture(s) B of 0 to below 5 mg of KOH/g and olefinically polyunsaturated monomers in a proportion of 0.5 to 5 wt%, wherein the monomer composition of mixtures A and B is selected in such a manner that the calculated glass transition temperature (Tg) of a copolymer composed of a combination of only the olefinically monounsaturated monomers of mixtures A and B is in the range from 30 to 100 °C, wherein the ratio by weight of mixture A to the at least one mixture B is from 15:85 to 85:15 and wherein neutralization is not begun in process step 2) until at least 90 wt.% of the monomers of mixture A have been polymerized to completion.
Abstract:
A monomer recycle process for fluid phase in-line blending of polymers is provided. The monomer recycle process includes providing a first group (G1) of one or more reactor trains and a second group (G2) of one or more reactor trains and one or more separators fluidly connected to G1 and G2; polymerizing in each of G1 and G2 olefin monomers to form homogenous fluid phase polymer-monomer mixtures wherein each of the G1 and G2 have at least one common monomer; passing the reactor effluents from G1 through the G1 separators to separate a monomer-rich phase from a polymer-enriched phase, passing the polymer-enriched phase and the reactor effluents from G2 into the G2 separator to separate another monomer-rich phase from a polymer-rich blend, and recycling to each of G1 and G2 the separated monomer-rich phase from the G1 and G2 separators, respectively.
Abstract:
The invention generally provides for methods for controlling polymer properties. In particular, invention provides for methods for controlling the comonomer composition distribution of polyolefins such as ethylene alpha-olefin copolymers by altering at least one or more of the following parameters: the molar ratio of hydrogen to ethylene, the molar ratio of comonomer to ethylene, the partial pressure of ethylene, and the reactor temperature without substantially changing the density and/or the melt index of the copolymer.