Strain hardening enhanced polypropylene composition and production method thereof

Abstract

A polymer composition may comprise a first polymer component comprising polypropylene; a second polymer component comprising a high molecular weight copolymer having a weight average molecular weight greater than about 1 MDa; wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190 DEG C) of greater than 55 kPa.s. In some embodiments, a method can include preparing a polypropylene composition by a multi-stage polymerization comprising a first stage and a second stage, the first stage producing a propylene polymer and the second stage producing a high molecular weight copolymer having a weight average molecular weight greater than about 1 MDa; wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190 DEG C) of greater than 55 kPa.s.

Description

Technical Field

[0001] The presently disclosed subject matter relates to polypropylene compositions having balanced strain hardening and melt strength and methods of producing the same. Background Art

[0002] Polypropylene compositions are widely used in many commercial applications, but the melt strength and strain hardening properties of the material limit the compatibility with various manufacturing techniques. Especially, standard linear polypropylene shows poor performance in industrial operations (such as thermoforming, fiber stretching / spinning, blown film, foam etc.) including shear flow and extensional flow. This is partly due to its low melt strength and lack of strain hardening in common linear polypropylene. Several methods have been tried in industry to improve the melt strength and strain hardening of polypropylene, including increasing molecular weight, widening molecular weight distribution, adding ultra-high molecular weight tail, and / or adding long chain branching (LCB).

[0003] The polypropylene composition with high molecular weight tail can be produced by physical blending and / or by using reactor cascade, in which different reactors are produced polypropylene of different molecular weights and combined afterwards. However, the melt blending of polypropylene components often produces poor results such as low melt strength, reduced yield, and moderate increase of strain hardening. Producing the polypropylene part separately can increase production cost and produce slightly higher polymer of stiffness, but it can have the toughness that reduces because entanglement density is lower and / or homogeneity is not enough. Summary of the invention

[0004] The present disclosure relates to broad molecular weight polypropylene compositions having high molecular weight produced by a multi-stage polymerization process.

[0005] In one aspect, the composition disclosed herein relates to a polymer composition comprising a first polymer component comprising polypropylene; a second polymer component comprising a high molecular weight copolymer having a weight average molecular weight greater than about 1 MDa; wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190°C) greater than 55 kPa·s.

[0006] In another aspect, a method comprises preparing a polypropylene composition by a multi-stage polymerization comprising a first stage to produce a propylene polymer, and a second stage to produce a high molecular weight copolymer having a weight average molecular weight greater than about 1 MDa; wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190°C) greater than 55 kPa·s. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1is a schematic diagram of a two-stage polymerization process for producing a polypropylene composition having a high molecular weight tail.

[0008] Figure 2 is a schematic diagram of a multistage polymerization process with two gas phase reactors for producing a polypropylene composition having a high molecular weight tail.

[0009] Figure 3 is a schematic diagram of a multi-stage polymerization process with a prepolymerization reactor for producing a polypropylene composition having a high molecular weight tail.

[0010] Figure 4 is a graphical representation showing the molecular weight distribution of a comparative polypropylene produced by a conventional process.

[0011] Figure 5 is a graphical representation showing the molecular weight distribution of a comparative polypropylene produced by a conventional process.

[0012] Figure 6 is a graphical representation showing the extensional viscosity as a function of step time for polypropylene compositions prepared according to the present disclosure.

[0013] Figure 7 is a graphical representation showing the variation of extensional viscosity with step time for a comparative polypropylene composition.

[0014] Figure 8 is a graphical representation showing the extensional viscosity as a function of step time for polypropylene compositions prepared according to the present disclosure.

[0015] Fig. 9 is a graphical representation showing the extensional viscosity as a function of step time for polypropylene compositions prepared according to the present disclosure. DETAILED DESCRIPTION

[0016] The present disclosure relates to the generation of a wide molecular weight polypropylene composition with a high molecular weight portion ("high molecular weight tail" or "high MW tail"), which is produced by a multi-stage polymerization process. In any embodiment, the polypropylene composition may include a first polymer component and a second polymer component that forms a high MW tail (which increases peak tensile viscosity and strain hardening ratio) with a weight-average molecular weight greater than about 1 MDa. The polypropylene composition may show an increase in shear thinning, melt strength, and strain hardening, which may be suitable for use in applications including but not limited to foaming, blown film, thermoforming, and extruded profiles.

[0017] For the purposes of this disclosure, the following definitions shall apply:

[0018] As used herein, the terms “a”, “an” and “the” used herein are to be understood to include the plural as well as the singular.

[0019] As used herein, the term "density" refers to the density of a polymer independent of any additives (eg, antiblocking agents) that may alter the test value. Density is measured according to ASTM D-1505.

[0020] As used herein, the term "melt flow rate" or "MFR" is the number of grams extruded in 10 minutes under the action of a standard load and is an inverse measure of viscosity. A high MFR means low viscosity and a low MFR means high viscosity. In addition, polymers are shear thinning, which means that their resistance to flow decreases as the shear rate increases. This is due to molecular alignment and disentanglement in the direction of flow. As provided herein, MFR (I2, 230°C, 2.16 kg) is determined according to ASTM D-1238-E (20).

[0021] As used herein, “M n ” is the number average molecular weight, “M w ” is the weight average molecular weight, and “M z ” is the z-average molecular weight. Unless otherwise indicated, all molecular weight data are in molecular weight units (e.g., M w , M n , M z ) are all in g / mol.

[0022] As used herein, molecular weight distribution ("MWD") is equivalent to the expression M w / M n It is also called the polydispersity index (PDI). w / M n It is M w With M n The ratio of M w Provided by:

[0023]

[0024] M n Provided by:

[0025]

[0026] M z Provided by:

[0027]

[0028] The n in the previous equation is i The molecular weight is M i The number fraction of molecules. w , M n and M zThe measurement of is usually determined by gel permeation chromatography as disclosed in Macromolecules, Vol. 34, No. 19, p. 6812 (2001).

[0029] As used herein, "strain hardening" or cold working is the strengthening of a polymer when it is exposed to a deforming force. "Strain hardening" is manifested as an increase in stress required to cause an increase in strain when a polymer is plastically deformed. The strain hardening of polypropylene samples was measured using a TA Equipment ARES-G2 mechanical spectrometer.

[0030] "Strain hardening ratio" is defined as the ratio of two extensional viscosities: the numerator measured using an extensional viscometer reporting the maximum viscosity (at break) and the denominator of the extensional viscosity calculated from small amplitude strain experimental data using the method of Baumgaertel and Winter. It should be understood that the two extensional viscosities are measured using the same experimental conditions (i.e., temperature, stabilization, etc.).

[0031] The conventional molecular weight (IR M) is determined by combining the universal calibration relationship with the column calibration. w ), where column calibration was performed using a series of monodisperse polystyrene (PS) standards ranging from 700 to 10 M gm / mole. M at each elution volume was calculated using the following formula: w :

[0032]

[0033] Variables with the subscript "PS" represent polystyrene, while those without the subscript represent the test sample. In the present method, aPS=0.67 and KPS=0.000175, while a and K for other materials are calculated and disclosed in the literature (Sun, T. et al., Macromolecules, 2001, 34, 6812), except that for the purpose of the present disclosure, a=0.695 and K=0.000579 for linear ethylene polymers, a=0.705 and K=0.0002288 for linear propylene polymers, a=0.695 and K=0.000181 for linear butene polymers, a=0.695 and K=0.000579*(1-0.0087*w2b+0.000018*(w2b) for ethylene-propylene copolymers A2), where w2b is the bulk weight % of the butene comonomer, for ethylene-hexene copolymers a is 0.695 and K is 0.000579*(1-0.0075*w2b), where w2b is the bulk weight % of the hexene comonomer, and for ethylene-octene copolymers a is 0.695 and K is 0.000579*(1-0.0077*w2b), where w2b is the bulk weight % of the octene comonomer. Unless otherwise indicated, concentrations are in g / cm 3 The molecular weight is expressed in g / mole, and the intrinsic viscosity (and therefore K in the Mark-Houwink equation) is expressed in dL / g.

[0034] As used herein, the term "polypropylene" refers to a homopolymer of propylene monomers (propylene-derived units).

[0035] A "reactor" is any type of container or containment device, in any configuration of one or more reactors, and / or one or more reaction zones, in which similar polymers are produced; however, two or more reactors in fluid communication with each other may each produce different polymers.

[0036] As used herein, the terms "slurry polymerization", "slurry" and "slurry polymerization reactor" each refer to a process in which an olefin (e.g., propylene) is partially dissolved or insoluble in a polymerization medium. During slurry polymerization, catalyst components, solvent, α-olefin and hydrogen may be passed under pressure to one or more slurry polymerization reactors. Typically, the catalyst components are sent to a slurry polymerization reactor as a mixture in an aliphatic hydrocarbon solvent, in an oil, a mixture thereof or as a dry powder.

[0037] The term "gas phase polymerization" refers to the production of polymers in a gas phase reactor.

[0038] As used herein, the term "high molecular weight tail" or "high MW tail" refers to a polymer component comprising polymer chains having a weight average molecular weight greater than about 1 MDa. Specifically, gel permeation chromatography of a polypropylene composition having a high molecular weight tail will produce a multimodal molecular weight distribution in which the area under the curve at higher molecular weights produces a distinct hump, shoulder, or tail.

[0039] As used herein, "melt strength" refers to the stretch resistance of a polymer melt. The melt strength of a material is related to the entanglement of the molecular chains of the polymer and its resistance to disentanglement under strain. The polymer properties that affect the resistance to disentanglement are molecular weight, molecular weight distribution (MWD) and molecular branching. An extensional rheometer is used herein to measure melt strength at 190°C. The melt strength of a polymer at a specific temperature (e.g., 190°C) can be measured using a Gottfert Rheotens melt strength instrument (e.g., Gottfert Rheotens 71.97). The measurement is accomplished by: from a capillary rheometer (e.g., Gottfert Rheograph 2002 capillary rheometer), or from an extruder equipped with a capillary barrel, after the extrudate has been extruded 100mm, a variable speed gear is used to grab the extrudate and the extrudate is accelerated at a constant acceleration (12mm / s 2 , starting from an initial unstressed calibration speed of 10 mm / s, the gear speed is increased until the molten polymer strand breaks. The force in the strand is measured using a balance bar in conjunction with a linear variable displacement transducer. The force required to stretch and then break the extrudate is defined as the melt strength. Force is measured in hundredths of Newtons (cN). Common force versus wheel speed plots are known in the art to include a resonance immediately before the strand breaks. In such cases, the plateau force is approximated by the center line between oscillations.

[0040] As discussed above, the method for producing the polypropylene with high MW tail previously usually uses one or more physical blends and special catalyst / donor systems. However, current method can have various trade-offs in the physical property of the polypropylene composition obtained. For example, in physical blends, the dispersion of the high MW part can be limited due to the viscosity mismatch with the bulk polypropylene part, and processing can also cause the thermal-mechanical degradation of the high MW tail component. Similarly, using catalyst / donor systems can enhance the extensional viscosity that changes with MFR, but as MFR increases, the ratio of the high MW tail component usually reduces, and melt strength and elasticity are reduced.

[0041] Reactor processing designs are also performed in many variations to produce the high MW tail in a multi-stage polymerization process. A multi-stage polymerization process may include the use of multiple reactors, such as a prepolymerization loop (or "babyloop"), a slurry polymerization reactor (or "slurry loop"), and one or more gas phase reactors. By selectively controlling through a series of reactors, different polymer fractions may be produced in a single continuous process. In some cases, a first polymer fraction may be produced in a polymerization stage and transferred to a subsequent stage where additional polymer fractions are produced in the presence of the first polymer fraction or by modifying the first polymer fraction.

[0042] Generally, reducing the MFR of a polymer composition involves reducing the concentration of chain transfer agents such as hydrogen used during polymerization, which allows the polymer chains to be more extended and produces a higher MW polymer fraction. However, reducing the concentration of chain transfer agents can also reduce catalyst activity and overall productivity. Another compounding factor is the residence time in the reactor stage, which generally limits the maximum proportion of high MW tails that can be produced and the associated physical property modifications.

[0043] Method disclosed herein includes preparing a polypropylene composition having a wide MWD and a high MW tail of different concentrations and enhanced extensional viscosity, melt strength, strain hardening and outstanding properties by multistage polymerization. Polypropylene composition disclosed herein may include a mixture of a first polypropylene polymer or copolymer and a second high MW tail component dispersed therein. In some cases, the first polymer component may contain a polypropylene polymer or copolymer, which may have an MWD of about 6.5 to about 8.5. The second high MW tail component may have a weight average molecular weight greater than about 1MDa, which exists in a weight percentage (wt%) of about 2 wt % or greater. In some cases, the polypropylene composition may include a high MW tail of the weight percentage (wt %) of the high MW tail in the range of about 2 wt % to about 15 wt %, about 2 wt % to about 12 wt %, or about 2 wt % to about 12 wt %. In some cases, the polypropylene composition may have an overall MWD of at least 10 and an Mz of at least 100kDa.

[0044] Method disclosed herein may include a multi-stage polymerization process, which has a first stage in which the polypropylene polymerization reaction produces a first polypropylene or copolymer and a second stage in which a second polymer forming a high MW tail component is produced. The high MW tail can be produced in a single reactor (or a reactor stage containing multiple reactors) before or after producing the first polypropylene polymer or copolymer. In some cases, the high MW tail component can be produced at multiple points (e.g., in one or more reactors and / or stages) by a multi-stage polymerization process, including producing multiple parts at two or more points. The method described herein can be used in combination with other technologies to adjust strain hardening and melt strength, including post-reactor modification by crosslinking or blending with other polymers and additives. The multi-stage polymerization process disclosed herein may also include producing a multiphase copolymer composition (e.g., impact copolymer) by crosslinking and / or polymerization of the internal phase in the polypropylene polymer portion.

[0045] The multi-stage polymerization process disclosed herein is relatively modular and may include various prepolymerization methods and reactor arrangements. The process may include the use of a prepolymerization loop (e.g., a mini-loop), a slurry phase loop / reactor, and / or a gas phase reactor. Commercial reactor arrangements may include ExxonMobil or Spheripol TMProcess (1 or 2 slurry loops in series plus 1, 2 or 3 gas phase reactors). By selectively controlling the prepolymerization reactor, slurry phase and / or gas phase reactor(s), different concentrations, comonomer or ter-monomer compositions, molecular weights, high molecular weight tails of molecular weight distribution can be prepared to produce polypropylene compositions with broad molecular weight distribution and high molecular weight tails.

[0046] The multi-stage polymerization process disclosed herein can control the proportion and weight average weight of the high MW tail by one or more of the comonomer feed, chain transfer agent concentration, and residence time in the reactor. In some cases, the process disclosed herein can produce an increased fraction of the high MW tail by adding a comonomer (e.g., ethylene) having a higher reactivity with the selected catalyst than the main propylene monomer (or comonomer mixture). Comonomers suitable for use in the polymerization process disclosed herein include C1-C 20 Olefins such as ethylene, propylene, butene, hexene, octene, etc.; and polyunsaturated C1-C 20 Monomers such as butadiene, norbornene, ethylidene norbornene, vinyl norbornene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 1,6-octadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, and the like; and mixtures thereof.

[0047] The comonomer can be added with a mole percentage (mol %) of total monomer molar content in the range of about 1 mol % to about 10 mol %, about 1 mol % to about 7 mol %, or about 2 mol % to about 5 mol %. In some embodiments, the comonomer can be added with about 1 mol % or more, about 2 mol % or more, or about 4 mol % or more. The polypropylene composition produced by the present method can have a weight percentage (wt %) of comonomer in the range of about 2 wt % to about 10 wt % measured by Fourier transform infrared (FTIR) spectroscopy.

[0048] The concentration of the chain transfer agent can be modified in at least one of the first stage and the second stage to control the overall molecular weight of the polymer being produced in each stage. In any embodiment, the molar ratio of chain transfer agent (e.g., hydrogen) to monomer reactant (e.g., propylene, olefin, or comonomer mixture) in the reactor or stage can be from 0 to about 0.5, from about 0.01 to about 0.5, from about 0.02 to about 0.3, from about 0.05 to about 0.3, or from about 0 to about 0.01.

[0049] Ratio and the overall molecular weight of the first polypropylene polymer or multipolymer and / or high MW tail component can also be controlled by the residence time in the stage of regulating the production of each component.In any embodiment, the residence time in the stage of producing the first polypropylene polymer or multipolymer can be from about 30 minutes to about 120 minutes, from about 40 minutes to about 100 minutes, or from about 40 minutes to about 70 minutes.In any embodiment, the residence time in the stage of producing high MW tail component can be from about 30 minutes to about 240 minutes, from about 50 minutes to about 200 minutes, or from about 80 minutes to about 150 minutes.

[0050] The various stages and components used in the multi-stage polymerization processes discussed herein are discussed in more detail in the following sections.

[0051] Prepolymerization

[0052] The method disclosed herein may include a prepolymerization step, wherein one or more monomers are combined in a liquid phase, which may also contain one or more reactants or inert components. The prepolymerization may be carried out in a continuous stirred tank reactor or a loop reactor and may be carried out at any suitable temperature, such as from about 0°C to about 60°C, from about 10°C to about 50°C, or from about 20°C to about 45°C. The pressure of the prepolymerization reaction is not critical, but is often maintained so that the reaction mixture is in the liquid phase, such as from about 275 psig to about 1435 psig, or from about 420 to about 1000 bar.

[0053] During the prepolymerization, monomers may be fed into the prepolymerization reactor. The amount of prepolymer produced on the selected catalyst during the prepolymerization may be from about 10 to about 1000 grams per gram of solid catalyst component, or from about 50 to about 500 grams per gram of solid catalyst component. The methods disclosed herein may include recovering catalyst particles from a continuously stirred prepolymerization reactor, wherein the catalyst particles may have different amounts of polymers attached thereto, depending on the residence time in the prepolymerization reactor.

[0054] The prepolymerization reaction may include the introduction of one or more catalyst systems, which may include one or more primary catalysts and / or co-catalysts. The methods disclosed herein may include adding a catalyst system at one or more points in a multi-stage polymerization (e.g., during a prepolymerization and one or more subsequent stages). Other components, such as chain transfer agents, antistatic agents, promoters, scavengers, etc., may be added during the prepolymerization stage.

[0055] Catalyst system

[0056] The catalyst system according to the present disclosure may include at least one catalyst, at least one internal electron donor, one or more external electron donors, a cocatalyst, and / or a support, wherein the catalyst system can polymerize propylene monomer under polymerization conditions of suitable temperature and pressure to produce a propylene composition. In addition to the multi-stage polymerization process disclosed herein, a variety of catalysts and donors having desired characteristics (including broad MWD, MW of high MW tail and / or amount of high molecular weight tail) can also be used to produce a propylene composition.

[0057] In some embodiments, the catalyst system may include a Ziegler-Natta and / or metallocene catalyst used with one or more donors and cocatalysts, such as solid titanium-supported catalyst systems described in U.S. Pat. Nos. 4,990,479 and 5,159,021, and PCT Publication No. WO 00 / 63261, among others. Briefly, a Ziegler-Natta catalyst may be obtained by: (1) suspending a dialkoxymagnesium compound in an aromatic hydrocarbon that is liquid at ambient temperature; (2) contacting the dialkoxymagnesium hydrocarbon composition with a titanium halide and with a diester of an aromatic dicarboxylic acid; and (3) contacting the functionalized dialkoxymagnesium-hydrocarbon composition obtained in step (2) with additional titanium halide.

[0058] The solid titanium catalyst component can be prepared by contacting a magnesium compound, a titanium compound and at least an internal electron donor. Examples of the titanium compound used in the preparation of the solid titanium catalyst component include compounds having the formula Ti(OR n )X 4-n A tetravalent titanium compound wherein "R" is a hydrocarbyl group, "X" is a halogen atom, and "n" is 0 to 4. For the purposes of this disclosure, a hydrocarbyl group is defined as a C1-C 20 Group, or C1-C 10 groups, any of which may be linear, branched or cyclic (aromatic or non-aromatic) where applicable.

[0059] In any embodiment, titanium compounds suitable for use herein include: titanium tetrahalides such as TiCl4, TiBr4, and / or Ti I4; alkoxy titanium trihalides including Ti(OCH3)Cl3, Ti(OC2H5)Cl3, Ti(OC4H9)Cl3, Ti(OC2H5)Br3, and / or Ti(Oiso-C4H9)Br3; dialkoxy titanium dihalides including Ti(OCH3)2Cl2, Ti(OC2H5)2Cl2, Ti(Onormal-C4H9)2Cl2 and / or Ti(OC2H5)2Br2; trialkoxy titanium monohalides including Ti(OCH3)3Cl, Ti(OC2H5)3Cl, Ti(Onormal-C4H9)3Cl and / or Ti(OC2H5)3Br; and / or tetraalkoxy titanium including Ti(OCH3)4, Ti(OC2H5)4, and / or Ti(Onormal-C4H9).

[0060] In any embodiment, the halogen-containing titanium compound can be titanium tetrahalide, or titanium tetrachloride. The titanium compounds can be used alone or in combination with each other. The titanium compound can be diluted with a hydrocarbon compound or a halogenated hydrocarbon compound.

[0061] In any embodiment, the magnesium compound used in the preparation of the solid titanium catalyst component can include a magnesium compound with reducing ability (or capable of alkyl substitution) and / or a magnesium compound without reducing ability. Suitable magnesium compounds with reducing ability can be, for example, magnesium compounds with magnesium-carbon bonds or magnesium-hydrogen bonds. Examples of useful magnesium compounds include dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium, dipentyl magnesium, dihexyl magnesium, didecyl magnesium, ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, amyl magnesium chloride, butyl ethoxy magnesium, ethyl butyl magnesium, and / or butyl magnesium halide. These magnesium compounds can be used alone or they can form complexes with the organoaluminum cocatalyst described herein. These magnesium compounds can be liquid or solid. In combination with magnesium compounds, titanium-based Ziegler Natta catalysts are said to be supported and are therefore the solid portion of the catalyst.

[0062] Suitable examples of the magnesium compound having no reducing ability include: magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; alkoxymagnesium halides such as methoxymagnesium chloride, ethoxymagnesium chloride, isopropoxymagnesium chloride, phenoxymagnesium chloride, and methylphenoxymagnesium chloride; alkoxymagnesium such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octyloxymagnesium, and 2-ethylhexyloxymagnesium; aryloxymagnesium such as phenoxymagnesium and dimethylphenoxymagnesium; and / or magnesium carboxylates such as magnesium laurate and magnesium stearate.

[0063] In any embodiment, the non-reducible magnesium compound may be a compound derived from a magnesium compound having a reducing ability, or may be a compound derived when preparing the catalyst component. The magnesium compound having no reducing ability may be derived from a compound having a reducing ability, for example, by contacting a magnesium compound having a reducing ability with a polysiloxane compound, a halogen-containing silane compound, a halogen-containing aluminum compound, an ester, an alcohol, etc.

[0064] In any embodiment, the magnesium compound having reducing ability and / or the magnesium compound not having reducing ability may be a complex of the above magnesium compound and other metals, or a mixture thereof with other metal compounds. They may also be a mixture of two or more types of the above compounds. In any embodiment, halogen-containing magnesium compounds including magnesium chloride, alkoxymagnesium chloride and aryloxymagnesium chloride may be used.

[0065] In any embodiment, a suitable solid catalyst component comprising a non-aromatic internal electron donor can be the catalyst solid. Such catalysts are used to illustrate the present invention, and other titanium-supported catalyst systems are contemplated. The mechanisms used by other catalysts include, but are not limited to, intermittent prepolymerization, in-situ prepolymerization, and other such mechanisms.

[0066] Activator

[0067] In any embodiment, the catalyst system comprises a Ziegler-Natta catalyst used in combination with an activator (also referred to herein as a Ziegler-Natta activator). In any embodiment, a compound containing at least one aluminum-carbon bond in the molecule may be used as an activator, also referred to herein as an organoaluminum activator or an organoaluminum compound. Suitable organoaluminum compounds include compounds of the general formula R l m Al(OR 2 ) n H p X q An organoaluminum compound, wherein R 1 and R 2 are the same or different, and each represents C1-C 15 A hydrocarbon group (alkyl or aryl), a C1-C4 alkyl group; "X" represents a halogen atom; and "m" is 1, 2 or 3; "n" is 0, 1 or 2; "p" is 0, 1, 2 or 3; and "q" is 0, 1 or 2; and wherein m+n+p+q=3.

[0068] Other suitable organoaluminum compounds include aluminum complex alkyl compounds represented by the general formula M1A1R, wherein M1 is lithium, sodium or potassium, and R1 is as defined above. Suitable organoaluminum compounds include those represented by the general formula R 1 m Al(OR 2 )3-m The represented compound, wherein R 1 and R 2 are as defined above and m is preferably 1.5 < m < 3; R 1 m Al(H) 3-m , wherein R 1 is as defined above, X is a halogen, and m is 0 < m < 3, or 2 < m < 3; and / or R 1 m Al(OR 2 ) n X q , wherein R 1 and R 2 are as defined above, X is a halogen, 0 < m < 3, 0 < n < 3, 0 < q < 3, and m + n + q = 3.

[0069] Suitable examples of organoaluminum compounds include trialkylaluminums such as trimethylaluminum, triethylaluminum, and tributylaluminum; trienylaluminums such as triisoprenyl aluminum; dialkylalkoxyaluminums such as diethylethoxyaluminum and dibutylethoxyaluminum; alkyl sesquialkoxyaluminums such as ethyl sesquialethoxyaluminum and butyl sesquialbutoxyaluminum; partially alkoxylated alkylaluminums having an average composition represented by the general formula R 1 2.5 A1(OR 2 ) 0.5 ; partially halogenated alkylaluminums such as alkyldihalogenoaluminums such as ethyldichloroaluminum, propyldichloroaluminum, and butyldibromoaluminum; partially hydrogenated alkylaluminums such as alkyldihydroaluminums such as ethyldihydroaluminum and propyldihydroaluminum; and partially alkoxylated and halogenated alkylaluminums such as ethylethoxychloroaluminum, butylbutoxychloroaluminum, and ethylethoxybromoaluminum.

[0070] In any embodiment, the organoaluminum compound may contain two or more aluminum atoms bonded through oxygen or nitrogen atoms. Examples include (C2H5)2A1OA1(C2H5)2, (C4H9)2A1OA1(C4H9)2, LiAl(C2H5)4, and / or methylaluminoxane (MAO). In any embodiment, a trialkylaluminum and an alkylaluminum obtained by bonding at least two aluminum compounds can be used.

[0071] In any embodiment, the activator can be a halogen-free organoaluminum compound. Suitable halogen-free organoaluminum compounds are, in particular, branched unsubstituted alkylaluminum compounds of formula AIR3, wherein R represents an alkyl group with 1 to 10 carbon atoms, such as trimethylaluminum, triethylaluminum, triisobutylaluminum and tri(diisobutyl)aluminum (tridiisobutylaluminum). Additional compounds suitable for use as activators are readily available and are fully disclosed in the prior art including U.S. Patent No. 4,990,477. In any embodiment, the organoaluminum Ziegler-Natta activator can be trimethylaluminum, triethylaluminum (TEAL) or a combination thereof.

[0072] Internal electron donor

[0073] Electron donors are present with the metal components described above in forming a catalyst system suitable for producing the polypropylene compositions described herein. Both "internal" and "external" electron donors are desirable for forming a catalyst system suitable for preparing the polypropylene compositions described herein. Internal and external type electron donors are described, for example, in U.S. Patent No. 4,535,068.

[0074] Internal electron donors can be used in the formation reaction of the catalyst because the transition metal halide reacts with the metal hydride or metal alkyl. Examples of suitable internal electron donors include amines, amides, ethers, esters, ketones, nitriles, phosphines, stilbenes, arsines, phosphoramides, thioethers, thioesters, aldehydes, alcoholates, and salts of organic acids, any of which may contain aromatic groups. Internal electron donors are usually part of the solid catalyst component, while external electron donors are usually added separately from the solid catalyst component.

[0075] In any embodiment, the internal electron donor can be used in the formation reaction of the catalyst because the transition metal halide reacts with the metal hydride or the alkyl metal. Examples of suitable internal electron donors include amines, amides, ethers, esters, esters, ketones, nitrile, phosphine, stilbene, arsine, phosphoramide, thioether, thioester, aldehyde, alcoholate, and salts of organic acids. In any embodiment, the internal donor can be non-aromatic. In any embodiment, the non-aromatic internal electron donor can include aliphatic amines, amides, esters, ethers, ketones, nitrile, phosphine, phosphoramide, thioether, thioester, aldehyde, alcoholate, carboxylic acid or a combination thereof.

[0076] In any embodiment, the solid titanium catalyst component can be prepared using a non-aromatic internal electron donor. Examples of suitable non-aromatic internal electron donors include oxygen-containing electron donors such as alcohols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic oxides, ethers, amides and anhydrides; nitrogen-containing electron donors such as ammonia, amines, nitrile and / or isocyanate. Suitable examples include alcohols having 1 to 18 carbon atoms such as methanol, ethanol, propanol, pentanol, hexanol, octanol, 2-ethylhexanol, dodecanol, octadecyl alcohol, etc.; ketones having 3 to 15 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; aldehydes having 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde, octanal, etc.; organic acid esters having 2 to 30 carbon atoms, including esters that need to be included in the titanium catalyst component, such as methyl formate, ethyl formate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, ethyl stearate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, butene ethyl silicate, dibutyl maleate, diethyl butylmalonate, diethyl dibutylmalonate, ethyl cyclohexanecarboxylate, diethyl 1,2-cyclohexanedicarboxylate, di(2-ethylhexyl)1,2-cyclohexanedicarboxylate, γ-butyrolactone, δ-valerolactone, and / or ethylene carbonate; inorganic acid esters such as ethyl silicate and butyl silicate; acyl halides having 2 to 15 carbon atoms such as acetyl chloride and the like; ethers having 2 to 20 carbon atoms such as methyl ether, ethyl ether, isopropyl ether, butyl ether, pentyl ether, tetrahydrofuran and the like; amides such as acetamide and the like; acid anhydrides such as acetic anhydride and the like; amines such as methylamine, ethylamine, triethylamine, tributylamine, tetramethylethylenediamine and the like; and nitriles such as acetonitrile, trinitrile and the like.

[0077] In any embodiment, the non-aromatic internal electron donor comprises a substituted or unsubstituted C2-C 10 C1-C 20 In any embodiment, the non-aromatic internal electron donor can be a succinate according to Formula I:

[0078]

[0079] Where R 1 and R 2 Independently C1-C 20 A linear or branched alkyl, alkenyl or cycloalkyl hydrocarbon group; R 3 -R 6 are independently hydrogen, halogen or C1-C 20 A linear or branched alkyl, alkenyl or cycloalkyl hydrocarbon radical, wherein R 3 -R 6 The groups are not joined together, where R 3 -R 6 At least two of the groups are joined to form a cyclic divalent group, or a combination thereof.

[0080] In any embodiment, R of Formula I 3 -R 5 can be hydrogen and R 6 It may be a group selected from primary, branched, secondary or tertiary alkyl, or cycloalkyl groups having 3 to 20 carbon atoms.

[0081] In any embodiment, the internal donor can be a mono-substituted non-aromatic succinate compound. Suitable examples include diethyl sec-butylsuccinate, diethyl hexylsuccinate, diethyl cyclopropylsuccinate, diethyl trimethylsilylsuccinate, diethyl methoxysuccinate, diethyl cyclohexylsuccinate, diethyl (cyclohexylmethyl)succinate, diethyl tert-butylsuccinate, diethyl isobutylsuccinate, diethyl isopropylsuccinate, diethyl neopentylsuccinate, diethyl isopentylsuccinate, diethyl (1,1,1-trifluoro-2-propyl)succinate, diisobutyl sec-butylsuccinate, diisobutyl hexylsuccinate, diisobutyl cyclopropylsuccinate, diisobutyl trimethylsilylsuccinate, diisobutyl methoxysuccinate, diisobutyl cyclohexylsuccinate, diisobutyl (cyclohexylmethyl)succinate, tert-butylsuccinate, diethyl isobutylsuccinate, diethyl isopropylsuccinate, diethyl neopentylsuccinate, diethyl isopentylsuccinate, diethyl (1,1,1-trifluoro-2-propyl)succinate Diisobutyl butyl succinate, diisobutyl isobutyl succinate, diisobutyl isopropyl succinate, diisobutyl neopentyl succinate, diisobutyl isopentyl succinate, diisobutyl (1,1,1-trifluoro-2-propyl) succinate, dineopentyl sec-butyl succinate, dineopentyl hexyl succinate, dineopentyl cyclopropyl succinate, dineopentyl trimethylsilyl succinate, dineopentyl methoxy succinate, dineopentyl cyclohexyl succinate, dineopentyl (cyclohexylmethyl) succinate, dineopentyl tert-butyl succinate, dineopentyl isobutyl succinate, dineopentyl isopropyl succinate, dineopentyl neopentyl succinate, dineopentyl isopentyl succinate, and / or dineopentyl (1,1,1-trifluoro-2-propyl) succinate.

[0082] In any embodiment, the internal electron donor having a structure consistent with Formula I comprises R 3 -R 6 At least two groups in the 20Linear or branched alkyl, alkenyl, and / or cycloalkyl hydrocarbon radical, it may contain heteroatoms. In any embodiment, two radicals different from hydrogen may be connected to the same carbon atom. Suitable examples include 2,2-disubstituted succinates, including diethyl 2,2-dimethylsuccinate, diethyl 2-ethyl-2-methylsuccinate, diethyl 2-(cyclohexylmethyl)-2-isobutylsuccinate, diethyl 2-cyclopentyl-2-n-propylsuccinate, diethyl 2,2-diisobutylsuccinate, diethyl 2-cyclohexyl-2-ethylsuccinate, diethyl 2-isopropyl-2-methylsuccinate, diethyl 2,2-diisopropyl-2-methylsuccinate. 2-(1,1,1-trifluoro-2-propyl)-2-methylsuccinate, diethyl 2-isopentyl-2-isobutylsuccinate, diisobutyl 2,2-dimethylsuccinate, diisobutyl 2-ethyl-2-methylsuccinate, diisobutyl 2-(cyclohexylmethyl)-2-isobutylsuccinate, diisobutyl 2-cyclopentyl-2-n-propylsuccinate, diisobutyl 2,2-diisobutylsuccinate, 2-cyclohexyl-2-ethylsuccinate Diisobutyl 2-isopropyl-2-methylsuccinate, diisobutyl 2-isobutyl-2-ethylsuccinate, diisobutyl 2-(1,1,1-trifluoro-2-propyl)-2-methylsuccinate, diisobutyl 2-isopentyl-2-isobutylsuccinate, diisobutyl 2,2-diisopropylsuccinate, dineopentyl 2,2-dimethylsuccinate, dineopentyl 2-ethyl-2-methylsuccinate, dineopentyl 2-(cyclohexylmethyl)-2-isobutylsuccinate dineopentyl 2-isobutylsuccinate, dineopentyl 2-cyclohexyl-2-ethylsuccinate, dineopentyl 2-isopropyl-2-methylsuccinate, dineopentyl 2-isobutyl-2-ethylsuccinate, dineopentyl 2-(1,1,1-trifluoro-2-propyl)-2-methylsuccinate, dineopentyl 2,2-diisopropylsuccinate, and / or dineopentyl 2-isopentyl-2-isobutylsuccinate.

[0083] In any embodiment, at least two groups different from hydrogen may be attached to different carbon atoms between R3-R6. Examples include R3 and R5 or R4 and R6. Suitable non-aromatic succinate compounds include: diethyl 2,3-bis(trimethylsilyl)succinate, diethyl 2,2-sec-butyl-3-methylsuccinate, diethyl 2-(3,3,3-trifluoropropyl)-3-methylsuccinate, diethyl 2,3-bis(2-ethylbutyl)succinate, diethyl 2,3-diethyl-2-isopropylsuccinate, diethyl 2,3-diisopropyl-2-methylsuccinate, diethyl 2,3-dicyclohexyl-2-methylsuccinate, diethyl 2,3-diisopropylsuccinate, diethyl 2,3-bis(cyclohexylmethyl)succinate, diethyl 2,3-di-tert-butylsuccinate, diethyl 2,3-diisobutylsuccinate, 2,3-dineopentyl Diethyl succinate, diethyl 2,3-diisopentylsuccinate, diethyl 2,3-(1-trifluoromethyl-ethyl)succinate, diethyl 2-isopropyl-3-isobutylsuccinate, diethyl 2-tert-butyl-3-isopropylsuccinate, diethyl 2-isopropyl-3-cyclohexylsuccinate, diethyl 2-isopentyl-3-cyclohexylsuccinate, diethyl 2-cyclohexyl-3-cyclopentylsuccinate, diethyl 2,2,3,3-tetramethylsuccinate, diethyl 2,2,3,3-tetraethylsuccinate, diethyl 2,2,3,3-tetrapropylsuccinate, diethyl 2,3-diethyl-2,3-diisopropylsuccinate, diisobutyl 2,3-bis(trimethylsilyl)succinate, 2, 2-sec-butyl-3-methylsuccinate, 2-(3,3,3-trifluoropropyl)-3-methylsuccinate, 2,3-bis(2-ethylbutyl)succinate, 2,3-diethyl-2-isopropylsuccinate, 2,3-diisopropyl-2-methylsuccinate, 2,3-dicyclohexyl-2-methylsuccinate, 2,3-diisopropylsuccinate, 2,3-bis(cyclohexylmethyl)succinate, 2,3-di-tert-butylsuccinate, 2,3-diisobutylsuccinate, 2,3-diisobutylsuccinate, 2,3-dineopentylsuccinate, 2,3-diisopentylsuccinate, 2,3-(1, 1,1-trifluoro-2-propyl)succinate, diisobutyl 2,3-n-propyl succinate, diisobutyl 2-isopropyl-3-isobutyl succinate, diisobutyl 2-tert-butyl-3-isopropyl succinate, diisobutyl 2-isopropyl-3-cyclohexyl succinate, diisobutyl 2-isopentyl-3-cyclohexyl succinate, diisobutyl 2-n-propyl-3-(cyclohexylmethyl) succinate, diisobutyl 2-cyclohexyl-3-cyclopentyl succinate, diisobutyl 2,2,3,3-tetramethyl succinate, diisobutyl 2,2,3,3-tetraethyl succinate, diisobutyl 2,2,3,3-tetrapropyl succinate, diisobutyl 2,3-diethyl-2,3-diisopropyl succinate, 2,Dineopentyl 3-bis(trimethylsilyl)succinate, Dineopentyl 2,2-di-sec-butyl-3-methylsuccinate, Dineopentyl 2-(3,3,3-trifluoropropyl)-3-methylsuccinate, Dineopentyl 2,3-bis(2-ethylbutyl)succinate, Dineopentyl 2,3-diethyl-2-isopropylsuccinate, Dineopentyl 2,3-diisopropyl-2-methylsuccinate, Dineopentyl 2,3-dicyclohexyl-2-methylsuccinate, Dineopentyl 2,3-diisopropylsuccinate, Dineopentyl 2,3-bis(cyclohexylmethyl)succinate, Dineopentyl 2,3-di-tert-butylsuccinate, Dineopentyl 2,3-diisobutylsuccinate, Dineopentyl 2,3-dineopentylsuccinate, Dineopentyl 2,3-diisopentylsuccinate dineopentyl 2-isopropyl-3-isobutylsuccinate, dineopentyl 2-tert-butyl-3-isopropylsuccinate, dineopentyl 2-isopropyl-3-cyclohexylsuccinate, dineopentyl 2-isopentyl-3-cyclohexylsuccinate, dineopentyl 2-n-propyl-3-(cyclohexylmethyl)succinate, dineopentyl 2-cyclohexyl-3-cyclopentylsuccinate, dineopentyl 2,2,3,3-tetramethylsuccinate, dineopentyl 2,2,3,3-tetraethylsuccinate, dineopentyl 2,2,3,3-tetrapropylsuccinate, and / or dineopentyl 2,3-diethyl-2,3-diisopropylsuccinate. ,

[0084] In any embodiment, the compound according to formula I may comprise a group R 3 -R 6 Two or four of the carbon atoms are bonded to the same carbon atom, which are linked together to form a cyclic multivalent group. Examples of suitable compounds include 1-(ethoxycarbonyl)-1-(ethoxyacetyl)-2,6-dimethylcyclohexane, 1-(ethoxycarbonyl)-1-(ethoxyacetyl)-2,5-dimethylcyclopentane, 1-(ethoxycarbonyl)-1-(ethoxyacetylmethyl)-2-methylcyclohexane, and / or 1-(ethoxycarbonyl)-1-(ethoxy(cyclohexyl)acetyl)cyclohexane.

[0085] For the purposes of this paper, all above-mentioned compounds can be used in the form of pure stereoisomers or in the form of mixtures of enantiomers, or mixtures of diastereomers and enantiomers. When pure isomers are used, they can be separated using common techniques known in the art. In particular, some succinates of the present invention can be used as pure racemic or meso forms or mixtures thereof, respectively.

[0086] In any embodiment, the internal electron donor compound can be selected from diethyl 2,3-diisopropylsuccinate, diisobutyl 2,3-diisopropylsuccinate, di-n-butyl 2,3-diisopropylsuccinate, diethyl 2,3-dicyclohexyl-2-methylsuccinate, diisobutyl 2,3-dicyclohexyl-2-methylsuccinate, diisobutyl 2,2-dimethylsuccinate, diethyl 2,2-dimethylsuccinate, diethyl 2-ethyl-2-methylsuccinate, diisobutyl 2-ethyl-2-methylsuccinate, diethyl 2-(cyclohexylmethyl)-3-ethyl-3-methylsuccinate, diisobutyl 2-(cyclohexylmethyl)-3-ethyl-3-methylsuccinate, and combinations thereof.

[0087] External electron donor

[0088] In any embodiment, along with the internal donor, two or more external electron donors may also be used in combination with the catalyst in the catalyst system. External electron donors include, but are not limited to, organosilicon compounds, such as tetraethoxysilane (TEOS), methylcyclohexyldimethoxysilane (MCMS), propyltriethoxysilane (PTES) and dicyclopentyldimethoxysilane (DCPMS). For example, in any embodiment, the external electron donor may be PTES / DCPMS, a metal chelating monomer ("MCMS"), tetraethoxysilane ("TEOS"), propyltriethoxysilane ("PTES") and / or a blend of tetraethoxysilane and DCPMS (also referred to as "TEOS / DCPMS") and / or others.

[0089] The use of organosilicon compounds as external electron donors is described, for example, in U.S. Pat. No. 4,218,339; U.S. Pat. No. 4,395,360; U.S. Pat. No. 4,328,122; and U.S. Pat. No. 4,473,660. The external electron donor acts to control stereoregularity, which affects the amount of isotactic versus atactic polymer produced in a given system. The more stereoregular the isotactic polymer, the more crystalline it is, which results in a material with a higher flexural modulus. As a result of reduced hydrogen response during polymerization, highly crystalline isotactic polymers also exhibit low MFR. The stereoregularity and hydrogen response of a given external electron donor are directly related and inversely related. DCPMS donors have a much lower hydrogen response than PTES donors, but produce much higher levels of stereoregularity than PTES.

[0090] In any embodiment, the two external electron donors A and B, also referred to herein as the first external electron donor and the second external electron donor, may be selected so that the melt flow rate MFR (A) of the polypropylene composition obtained by homogenizing polypropylene using the first external electron donor (A) in combination with a solid titanium catalyst component and an organoaluminum compound catalyst component and the MFR (B) of the polypropylene composition obtained by homogenizing polypropylene using the second external electron donor (B) under the same conditions as the use of the external electron donor (A) have the following relationship: 1.2 <log[MFR(5) / MFR(A)]<1.4。

[0091] The external electron donors used to prepare the electron donor catalyst component may be those used to prepare the solid titanium catalyst component. In any embodiment, each of the external electron donors (A) and (B) may comprise an organosilicon compound.

[0092] In any embodiment, one or more of the external electron donors may comprise the formula R 3 n Si(OR 4 ) 4-n >organosilicon compounds, wherein R 3 and R 4 independently represent a hydrocarbon group and 0 <n<4。

[0093] Examples of suitable organosilicon compounds include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldiethoxysilane, tert-butylmethyl-n-diethoxysilane, tert-butylmethyldiethoxysilane, tert-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, diethylphenyldimethoxysilane, dicyclohexyldiethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, Methoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, [γ]-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, tert-butyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornyltriethoxysilane, 2-norbornylmethyldimethoxysilane, ethyl silicate, butyl decanoate, trimethylphenoxysilane, methylallyloxysilane, vinyltri(β-methoxyethoxysilane), vinyltriacetoxysilane, and / or dimethyltetraethoxydisilane.

[0094] In any embodiment, one of the two or more organosilicon compounds may comprise a compound of formula R 1 2Si(OR 2 )2, where R 1 represents a hydrocarbyl group in which the carbon adjacent to Si is a secondary or tertiary carbon. Suitable examples include substituted and unsubstituted alkyl groups such as isopropyl, sec-butyl, tert-butyl and tert-pentyl groups, cycloalkyl groups such as cyclopentyl and cyclohexyl groups, cycloalkenyl groups such as cyclopentenyl groups, and aryl groups such as phenyl and tolyl groups. In any embodiment, R 2 It may represent a hydrocarbyl group or a hydrocarbyl group having 1 to 5 carbon atoms, or a hydrocarbyl group having 1 or 2 carbon atoms.

[0095] Examples of suitable silicone compounds include diisopropyldimethoxysilane, diisopropyldiethoxysilane, di-sec-butyldimethoxysilane, di-tert-butyldimethoxysilane, di-tert-pentyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, diphenyldimethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, and / or bis-ethylphenyldimethoxysilane.

[0096] In any embodiment, the silicone compound can be represented by the following general formula R 1 n Si(OR 2 ) 4-n wherein n is 2, and R 1 each represent a hydrocarbon group and at least one of the two hydrocarbon groups is a hydrocarbon group in which the carbon adjacent to Si is a primary carbon. Examples of suitable hydrocarbon groups include alkyl groups such as ethyl, n-propyl, and n-butyl groups, aralkyl groups such as cumyl and benzyl groups, and alkenyl groups such as vinyl groups, etc.

[0097] In any embodiment, R 2 can represent a hydrocarbon group preferably having 1 to 5 carbon atoms, or 1 to 2 carbon atoms. Suitable examples of silicone compounds where n is 2 include diethyldimethoxysilane, dipropyldimethoxysilane, di-n-butyldimethoxysilane, dibenzyldimethoxysilane, and / or divinyldimethoxysilane.

[0098] Examples of suitable compounds when 0 < n < 2 or 2 < n < 4 include cases where R 1 is an alkyl, cycloalkyl, alkenyl, aryl, or aralkyl group and R 2 represents a hydrocarbon group having 1 to 5 carbon atoms or 1 to 2 carbon atoms.

[0099] Suitable examples of organosilicon compounds where 0 < n < 2 or 2 < n < 4 include trimethylmethoxysilane, trimethylethoxysilane, methyl - phenyldimethoxysilane, methyltrimethoxysilane, tert - butyl - methyldimethoxysilane, tert - butylmethyldiethoxysilane, tert - amylmethyldimethoxysilane, phenylmethyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, decyl - trimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, propyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, 2 - norbornyltrimethoxysilane, and / or 2 - norbornyltriethoxysilane. In any embodiment, the external electron donor includes methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, propyltrimethoxysilane, decyl - trimethoxysilane, decyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltributoxysilane, and / or cyclohexyltrimethoxysilane.

[0100] In any embodiment, the organosilicon compounds disclosed above can be used such that a compound that can be converted into such an organosilicon compound is added during the polymerization or prepolymerization of olefins, and the organosilicon compound can be formed in situ during the olefin polymerization or prepolymerization.

[0101] In any embodiment, the first external electron donor can have the formula R 1 2Si(OR 2 )2, where each R 1 is independently a hydrocarbyl group containing 1 to 10 carbon atoms, where the carbon atom adjacent to Si is a secondary or tertiary carbon atom, each R 2 is independently a hydrocarbyl group containing 1 to 10 carbon atoms, and the second external electron donor has the formula R 3 n Si(OR 4 )4 - n>, where R 3 and R 4 are each independently a hydrocarbyl group containing 1 to 10 carbon atoms, and n is 1, 2, or 3, and the second external electron donor is different from the first external electron donor.

[0102] In any embodiment, the first external electron donor and the second external electron donor are selected from tetraethoxysilane, methylcyclohexyldimethoxysilane, propyltriethoxysilane, dicyclopentyldimethoxysilane, and combinations thereof. In any embodiment, based on the total mole % of the external electron donors, the Ziegler-Natta catalyst system can comprise from 2.5 mole % to less than 50 mole % of the first external electron donor and greater than 50 mole % of the second external electron donor. In any embodiment, the first electron donor can comprise dicyclopentyldimethoxysilane (“DCPMS”) and the second external electron donor can comprise propyltriethoxysilane (“PTES”).

[0103] In any embodiment, the relationship between the first external electron donor and the second external electron donor can be defined by the formula 1.2 < log[MFR(B) / MFR(A)] < 1.4, where MFR(A) is the first melt flow rate of the homopolymer formed by polymerizing propylene monomers in the presence of a Ziegler-Natta catalyst and the first external electron donor, and where MFR(B) is the second melt flow rate of the homopolymer formed by polymerizing propylene monomers in the presence of a Ziegler-Natta catalyst and the second external electron donor, and where MFR(A) is lower than MFR(B).

[0104] In any embodiment, at least one, or two or more external electron donors are used in combination with the solid Ziegler-Natta catalyst component, provided that one of them is an aminosilane donor. The donor can be added to the polymerization reactor as a separate component together with the catalyst and the activator. As used herein, an “aminosilane” donor is an external electron donor having at least one amine or alkylamine moiety and at least one silane, alkylsilane, or siloxane moiety. In any embodiment, the external electron donor can include the general formula RSi and / or R 1 n Si(NR 2 2) 4-n of organosilicon compounds, where each R 1 is independently selected from hydrogen, C1-C 10 linear and branched alkyls and alkenes, C4-C 12 cycloalkyls and cycloalkenes, C5-C 14 aryl, C6-C 20 alkylaryl, C1-C 10 linear or branched alkoxys, C4-C 12 cycloalkoxys, C5-C 14 aryloxys, and C6-C 20 alkylaryloxys; each R 1 is independently selected from C1-C6 linear, branched, and cyclic alkyls or alkoxys; and each R 2 is independently selected from hydrogen, C1-C 10Linear and branched alkyl and alkenyl groups, C4-C 12 Cycloalkyl and cycloalkenyl, C5-C 14 Aryl and C6-C 20 Alkylaryl; each R 2 independently selected from C1-C5 linear or branched alkyl; and wherein "n" is 0, 1, 2 or 3.

[0105] Examples of suitable organosilicon and / or aminosilane compounds include dimethylamino-triethoxysilane, diethylamino-triethoxysilane, vinylethylamino-triethoxysilane, dipropylamino-triethoxysilane, dimethylamino-trimethoxysilane, dimethylamino-tripropylsilane, diethylamino-dicyclopentylmethoxysilane, diethylamino-dimethoxycyclohexylsilane, dipropylamino-vinyldimethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane , dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldiethoxysilane, tert-butylmethyl-n-diethoxysilane, tert-butylmethyldiethoxysilane, tert-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-ethylphenyldimethoxysilane, dicyclohexyldiethoxysilane , cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, g-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, tert-butyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, phenyltriethoxy silane, g-aminopropyltriethoxysilane, chlorotriethoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornyltriethoxysilane, 2-norbornylmethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methylallyloxysilane, vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, tetraethoxysilane, methylcyclohexyldimethoxysilane, propyltriethoxysilane, and / or dicyclopentyldimethoxysilane.

[0106] In any embodiment, the external electron donor may contain one or more aminosilane donors. Different external electron donors can be added into the first and / or second or more loop reactors to achieve polypropylene properties such as making polypropylene bimodal in MFR, molecular weight, crystallinity or some other properties. In one aspect, an external electron donor is added throughout the process and at the same concentration. In any embodiment, based on the total olefin concentration, the combined concentration of the external electron donor can be present in the reactor with 5ppm, 10ppm, 20ppm to 80,100 and 120ppm with the catalyst and olefin monomer (one or more).

[0107] In any embodiment, the concentration of the Ziegler-Natta catalyst in the polymerization system can be 2ppm, 4ppm, 8ppm to 20ppm, 40ppm, 60ppm, and 100ppm based on the total polypropylene concentration. In any embodiment, the organoaluminum activator can be present in an amount sufficient to produce 0.1 to 500g and 0.3 to 300g of polypropylene per gram of titanium catalyst present, and can be present in 0.1 to 100 moles and 0.5 to 50 moles per mole of titanium atom present in the catalyst component. In other words, the organoaluminum activator can be added in an amount of 10ppm, 20ppm, 40ppm to 80ppm, 100ppm, 140ppm, 180ppm, and 200ppm based on the total polypropylene concentration.

[0108] Multi-stage aggregation

[0109] The multistage polymerization process may include a sequential polymerization process in which one or more reactors are configured in series. After each polymerization, the product mixture is transferred to the next reactor (or reaction stage) in series until a polypropylene composition is obtained. For example, in order to produce the polypropylene composition disclosed herein, a primary polypropylene homopolymer or copolymer may be produced in a reactor or stage, while a high MW tail component is produced in a previous or subsequent reactor or stage.

[0110] The multistage polymerization process may include one or more reactor types, including one or more slurry (or liquid) phase polymerization reactors, such as stirred tank reactors, loop reactors, etc., and one or more gas phase polymerization reactors. For example, the multistage polymerization process may include a prepolymerization loop, one or more slurry polymerization reactors and one or more gas phase reactors operated in series to produce a polypropylene composition. Sequential polymerization techniques may include commercial processes such as Lyondel lBassel l's Spheripol TM Process or ExxonMobil's sequential polyolefin polymerization.

[0111] Slurry polymerization reactor

[0112] The multistage polymerization process may include one or more stages containing a slurry polymerization reactor. In slurry polymerization, monomer (or comonomer) is polymerized to produce polyolefin particles and to be suspended in a mixture of unreacted monomer and catalyst system. In some cases, the catalyst system may also become entrained in the growing particles. During slurry polymerization, the slurry is stirred so that reactants can be transferred to the reaction particles from the polymeric mixture. In any embodiment, a slurry polymerization reactor (or stage) may be used to produce a polypropylene homopolymer or copolymer with a molecular weight distribution of 6.5 to 8.5, and one or more other stages of the polymerization process (e.g., gas phase polymerization, slurry loop) may be used to produce a high MW tail component. It is also contemplated that a high MW tail component may also be produced in a slurry polymerization reactor or stage (one or more).

[0113] Slurry polymerization is sometimes referred to as "bulk polymerization", or "bulk slurry". Slurry polymerization is carried out with or without an inert diluent in a liquid polyolefin monomer. In any embodiment, the polyolefin monomer used for commercial production may contain some portion of aliphatic hydrocarbons as impurities. For example, propylene monomer may contain up to 5% propane as an impurity. In some cases, aliphatic hydrocarbons and other inert components may accumulate by the circulation of unreacted polyolefin monomer. Therefore, the effluent of the slurry polymerization reactor may contain up to 40% by weight of inert components. However, it should be understood that such a method is still within the meaning of "slurry polymerization".

[0114] In some cases, slurry polymerization may include a catalyst system containing a Ziegler-Natta catalyst and a first external electron donor. The slurry polymerization method disclosed herein may include a polymerization temperature of 60°C to 80°C, 62°C to 78°C, or 65°C to 75°C and the pressure of the slurry polymerization reactor is generally 430ps ig to 580ps ig, 450ps ig to 570ps ig, or 480ps ig to 560ps ig. However, the temperature and pressure of slurry polymerization may vary according to the properties of the selected catalyst system. In some cases, slurry polymerization may be carried out at a temperature higher than the critical temperature of the polymerization medium. Such reaction conditions are often referred to as "supercritical conditions". The term "supercritical fluid" is used to represent the fluid or fluid mixture under the temperature and pressure exceeding the critical temperature and pressure of the fluid or fluid mixture.

[0115] The slurry polymerization reactor can be any known reactor for polymerization of propylene monomer. The slurry polymerization reactor can be a continuous stirred tank reactor, a loop reactor, etc. In any embodiment, the slurry polymerization can be carried out in a loop reactor, wherein the slurry is circulated along a closed tube at a high speed by a circulation pump. Examples of loop reactors include U.S. Patent No. 4,582,816, U.S. Patent No. 3,405,109, U.S. Patent No. 3,324,093, EP 479186 and U.S. Patent No. 5,391,654.

[0116] As described herein, the slurry can be either continuously or intermittently extracted from the reactor. Intermittent extraction can include the use of settling legs, wherein the solid concentration of the slurry can be increased before the concentrated slurry batch is extracted from the reactor. The use of settling legs is disclosed in, for example, U.S. Patent No. 3,374,211, U.S. Patent No. 3,242,150, and EP 1310295. Continuous extraction is disclosed in, for example, EP 891990, EP 1415999, EP 1591460, and EP 1860125. In any embodiment, the continuous extraction method can be combined with a suitable concentration method, such as those disclosed in EP 1860125 and EP 1591460.

[0117] In the present method, a chain transfer agent such as hydrogen is used in a slurry reactor to control the molecular weight and melt flow rate of the polyolefin. In addition, the hydrogen feed sent to the slurry polymerization reactor is regulated to reach the target melt flow rate of the polypropylene composition. In addition, other process additives (such as chain transfer agents, antistatic agents, antifouling agents, scavengers, etc.) can also be introduced into the slurry polymerization reactor to promote the stable operation of the method.

[0118] In the multi-stage polymerization disclosed herein, the effluent containing polyolefin from the slurry polymerization reactor can be sent to the subsequent stage, including directly to the gas phase polymerization reactor, without the need for a flash step between reactors. Other processes using multi-stage polymerization are described in, for example, EP 887379, EP 887380, EP 887381 and EP 991684. In some cases, between the slurry phase polymerization and the gas phase polymerization, hydrogen is discharged from the polymerization medium in an amount of at least 80%.

[0119] Gas Phase Polymerization Reactor-Fluidized Bed Reactor

[0120] The multi-stage polymerization reactions disclosed herein may include a second stage of gas phase polymerization to produce a second type of polymer in the propylene composition disclosed herein, such as a high MW tail component. Although the examples may discuss that gas phase polymerization occurs after slurry polymerization, it is contemplated that gas phase polymerization may occur at any or multiple points in the multi-stage polymerization.

[0121] The polyolefin particles produced in the gas phase polymerization reactor can be fluidized with the help of a fluidizing gas comprising an olefin monomer, a comonomer (one or more), an inert gas, etc. In the gas phase polymerization reactor, the polymerization medium is introduced into an inlet chamber at the bottom of the reactor. In any embodiment, the gas phase polymerization reactor may contain a fluidized bed comprising growing polyolefin particles containing an active catalyst above a fluidizing grid. In order to ensure that the gas flow is evenly distributed over the cross-sectional area of ​​the inlet chamber, the inlet pipe may be equipped with a splitter element, such as disclosed in, for example, U.S. Patent No. 4,933,149 and EP 684871.

[0122] From the inlet chamber, the gas flow in the gas phase polymerization reactor passes upward through the fluidizing grid into the fluidized bed. The purpose of the fluidizing grid is to evenly distribute the cross section of the gas flow through the fluidized bed. In any embodiment, the fluidizing grid can be arranged to establish a gas stream to purge along the reactor wall, as disclosed in, for example, WO 05 / 087361. Other types of fluidizing grids are disclosed in, for example, U.S. Patent No. 4,578,879, EP 600414 and EP 721798. An overview of the function of fluidized bed reactors is provided in Geldart and Bayens: The Design of Distributors for Gas-fluidized Beds, Powder Technology, Vol. 42, 1985.

[0123] When the fluidizing gas contacts the bed containing the active catalyst, the reactive components of the gas (eg propylene monomer or comonomer) will react in the presence of the catalyst to produce a second polymer fraction.The fluidizing gas may be heated by an exothermic reaction.

[0124] Unreacted fluidizing gas can be removed from the top of the reactor and cooled in a heat exchanger to remove the heat of reaction. Unreacted fluidizing gas is cooled to a temperature below the bed temperature to prevent the bed from heating due to the reaction. The gas can be cooled to a temperature at which a portion of it condenses. When droplets enter the reaction, they are vaporized. The heat of vaporization contributes to the removal of the heat of reaction. This type of operation is referred to as condensing mode and its variants are disclosed in, for example, WO 2007 / 025640, U.S. Patent No. 4,543,399, EP 699213 and WO 94 / 25495. In any embodiment, a condensing agent can be added to the recycle gas stream, as disclosed in EP696293. The condensing agent may include non-polymerizable components, such as n-pentane, isopentane, n-butane or isobutane, etc.

[0125] After recovery from the heat exchanger, the unreacted fluidizing gas can be compressed and recycled to the inlet chamber of the reactor. Fresh reactants can also be introduced into the fluidizing gas stream before entering the gas phase polymerization reactor to compensate for losses caused by reaction and product withdrawal. The composition of the fluidizing gas can be analyzed and used to determine whether additional gas components should be added to maintain the desired reaction conditions.

[0126] The catalyst system can be introduced into the reactor in various ways, either continuously or intermittently, as discussed, for example, in WO 01 / 05845 and EP 499759. In the case where the gas phase polymerization reactor is part of a reactor cascade, the catalyst can be dispersed in polypropylene particles from the preceding polymerization stage. The polypropylene particles can be introduced into the gas phase polymerization reactor as disclosed in EP 1415999 and WO 00 / 26258. For example, if the preceding reactor is a slurry reactor, the slurry reactor effluent can be sent directly to the fluidized bed of the gas phase polymerization reactor as disclosed, inter alia, in EP 887379, EP 887380, EP 887381 and EP 991684.

[0127] The polypropylene composition can be withdrawn from the gas phase polymerization reactor either continuously or intermittently. Combinations of these methods can also be used. For example, continuous withdrawal is disclosed in WO 00 / 29452 and intermittent withdrawal is disclosed in U.S. Pat. No. 4,621,952, EP 188125, EP 250169 and EP 579426.

[0128] More specifically, the gas phase polymerization reactor may further comprise a disengagement zone, wherein the diameter of the reactor is increased to reduce the gas velocity and allow particles carried from the bed with the fluidizing gas to settle back into the bed. In addition, the level of the fluidized bed in a gas polymerization reactor may be observed by different techniques. For example, the pressure difference between the bottom of the reactor and a certain height of the bed may be recorded over the entire reactor length, and the bed level may be calculated based on the pressure difference in order to determine the time-averaged level.

[0129] In any embodiment, the level of the fluidized bed can be monitored by an ultrasonic sensor or a radioactive sensor. Here, an instantaneous level can be obtained, which can then be averaged over time to obtain a time-averaged bed level. In addition, the gas phase polymerization reactor may include a mechanical agitator to promote mixing in the fluidized bed. Examples of suitable agitator designs are provided in EP707513.

[0130] Gas phase polymerization can also be carried out in a "fast fluidized bed reactor" where the velocity of the fluidizing gas exceeds the initial velocity of pneumatic transport. The entire bed is then carried by the fluidizing gas. The gas transports the polypropylene particles to a separation device, such as a cyclone separator, where the gas is separated from the polypropylene particles.

[0131] In some cases, the polymer composition produced in the gas phase polymerization is transferred to a subsequent reaction zone, such as a settled bed or a fluidized bed or another fast fluidized bed reactor. On the other hand, the gas can be compressed, cooled and recycled to the bottom of the fast fluidized bed reactor. The combination of fast fluidized bed and settled bed is disclosed in, for example, WO 97 / 04015, WO 06 / 022736 and WO06 / 120187.

[0132] Gas Phase Polymerization Reactor - Settled Bed

[0133] Gas phase polymerization can also be carried out in a settled bed. In a settled bed, the polyolefin produced flows downward in a plug flow mode in an environment containing reactive components in the gas phase. The polyolefin powder is introduced into the bed from the top, from which it flows downward due to gravity. In any embodiment, reactants such as monomers and comonomers can be introduced anywhere in the reactor. However, in the case of gas flowing upward, its speed should not exceed the minimum fluidization velocity, because otherwise the downward flow of powder cannot be obtained. A gas buffer can be located at the top of the reactor so as to remove the reaction gas from the previous polymerization zone contained in the polypropylene powder as much as possible. The temperature of the settled bed can be controlled by adjusting the temperature and the ratio of the reactants and / or inert gas introduced into the settled bed zone. Polymerization in a settled bed is disclosed in, for example, EP 1633466, EP 1484343 and WO 97 / 04015.

[0134] Figure 1 , 2 and 3 are each schematic diagrams describing an exemplary multi-stage polymerization process and various reactor configurations suitable for use in the present disclosure. Figure 1 A two stage polymerization process is shown, comprising a slurry polymerization reactor stage 1 and a gas phase polymerization reactor stage 2. In this example, polypropylene homopolymer is produced in a slurry polymerization reactor 1 with a catalyst system, while a high MW tail component is produced in a gas phase polymerization reactor 2 with added comonomer.

[0135] like Figure 1 , the slurry polymerization reactor stage 1 comprises a slurry loop reactor having a plurality of loops 4. Each slurry loop 4 may further comprise a heat removal jacket 5. During polymerization in the slurry reactor 1, propylene monomer (and optional comonomer) is contacted with a catalyst system and a chain transfer agent (e.g. hydrogen) to produce an effluent 7 containing polypropylene polymer or copolymer, hydrogen, unreacted monomer and the catalyst system. The effluent 7 is continuously sent to the gas phase polymerization reactor stage 2. Further, liquid propylene monomer (i.e. pure propylene) or propylene monomer in solution (i.e. propylene with a diluent) is circulated through the slurry polymerization reactor 1 together with a polymerization catalyst and hydrogen using at least one reactor pump 6.

[0136] The gaseous reagents may be withdrawn from the effluent 7 after the slurry polymerization reactor 1 and before the gas phase polymerization reactor stage 2. Figure 1 and 2 It is shown that the chain transfer agent and unreacted monomer are separated from the effluent 7 by the separator 3. In the separator 3, the effluent 7 is separated into a light component stream 15 containing a mixture of unreacted monomer and hydrogen, and a heavy component stream 9 containing the first polypropylene polymer and the catalyst system. In any embodiment, the unreacted monomer can be sent to the gas phase polymerization reactor 2, including the unreacted monomer recovered from the separator 3.

[0137] After separation, Figure 1 As shown in FIG. 1 , the first polypropylene polymer and the catalyst system are fed to inlet 9 of gas phase polymerization reactor stage 2 to produce a high MW tail component. Figure 1 , 2 and 3, the gas phase polymerization reactor 12 is a vertical, cylindrical fluidized bed reactor having an expansion zone 12 above the fluidized bed 13. In the gas phase polymerization reactor stage 2, during polymerization, the polymerization medium flows into the expansion zone 12. Optionally, a recycle stream taken from the top of the gas phase polymerization reactor is connected to a cooler 10 and sent to the gas phase polymerization reactor by a pump 11. After polymerization, a polypropylene composition containing a high MW tail component can be discharged from the gas phase polymerization reactor outlet 14.

[0138] Figure 2 Another schematic diagram is provided in which a second gas phase polymerization reactor 16 is provided as the second reactor within the gas phase polymerization stage 2. The gas phase polymerization reactor 16 can serve to produce additional polymer components, including additional high MW tails. The gas phase polymerization reactor 16 can also be configured to produce additional polymer components such as ethylene-propylene rubber for producing an impact copolymer composition.

[0139] about Figure 3 , shows a multi-stage process, wherein polypropylene monomer and polymerization medium are fed into a prepolymerization reactor 40 via feed line 24, a catalyst system is fed via an external donor feed line 26, and an activator is fed via feed line 28. The prepolymerized polypropylene is then fed into a slurry polymerization reactor to continue polymer chain growth. A chain transfer agent such as hydrogen is injected into the slurry polymerization reactor 1 at the reactor input 30. In some cases, the polymerization medium may contain 500 mppm to 10,000 mppm of hydrogen based on the amount of monomer feed, but below the amount of the system bubble point.

[0140] The gaseous reagents can be separated from the effluent 7 by a separator 3 after the slurry polymerization reactor 1 and before the gas phase polymerization reactor 2. In the separator 3, the effluent 7 is separated into a light component stream 15 containing a mixture of unreacted monomers and hydrogen, and a heavy component stream 9 containing the first polypropylene polymer and the catalyst system. In any embodiment, the first polypropylene polymer is transferred to the gas phase polymerization reactor 12 via pipeline 9, wherein a high MW tail component is produced. In the gas phase polymerization reactor stage 2, during polymerization, the polymerization medium flows into the expansion zone 12. Optionally, a recycle stream taken from the top of the gas phase polymerization reactor is connected to a cooler 10 and sent to the gas phase polymerization reactor by a pump 11. After polymerization, a polypropylene composition containing a high MW tail component can be discharged from the gas phase polymerization reactor outlet 14.

[0141] exist Figure 1 , 2 and 3, the high MW tail component is formed in the gas phase polymerization reactor 12 after the polypropylene polymer component, however, the order of producing the components can be reversed or subdivided into different stages without departing from the current disclosure. For example, the high MW tail can be produced in the prepolymerization reactor 40 and / or the slurry reactor 1, while the polypropylene polymer component is produced in a subsequent stage (e.g., the slurry reactor 1 and / or the gas polymerization reactor 12). In addition, although Figure 1 , 2 and 3 show a number of components, such as compressors and pumps, but this configuration is for illustrative purposes only and the apparatus and / or method is not limited to the type of compressors and pumps used to promote and maintain the flow of polymerization medium, monomers and separated polyolefins and gases.

[0142] The propylene compositions disclosed herein may also be treated with various additives to induce post-reactor modifications. Post-reactor modification techniques may include incorporating crosslinking and branching by reaction with crosslinking agents such as peroxides, azides, maleic anhydride, amines, and mixtures thereof.

[0143] The polypropylene composition disclosed herein may also include one or more additives in one or more stages in a multistage polymerization process and / or before or after polymerization. Suitable additives may include mechanical and rheological modifiers, such as carbon nanomaterials such as carbon nanotubes, graphene, fullerene, diamond-like carbon, or carbon black, fibers, nanocrystalline cellulose, cellulose nanofibrils, silica, silica-alumina, alumina such as (pseudo) boehmite, gibbsite, titanium dioxide, zirconium oxide, cationic clays or anionic clays such as soapstone, bentonite, kaolin, sepiolite, hydrotalcite, etc. Additives may also include metal oxides such as alumina trihydrate (ATH), aluminum monohydrate (aluminum monohydrate), magnesium hydroxide, magnesium silicate, talc, silica such as fumed silica and precipitated silica, and calcium carbonate, calcium metasilicate, wollastonite, dolomite, perlite, hollow glass spheres, kaolin, etc.

[0144] Other additives may include fillers; antioxidants (e.g., hindered phenols such as IRGANOX available from Ciba-Geigy); T 1010 or IRGANO TM 1076); phosphites (e.g., IRGAFO available from Ciba-Geigy); TM 168); anti-sticking additives, tackifiers such as polybutene, terpene resins, aliphatic hydrocarbon resins and aromatic hydrocarbon resins, alkali metal stearates and glycerides, and hydrogenated rosin; UV stabilizers such as titanium oxide, zinc oxide, benzophenone, benzotriazole, aromatic esters, sterically hindered amines, etc.; heat stabilizers; anti-blocking agents; mold release agents; antistatic agents; pigments; colorants; dyes; waxes; silica; fillers; talc, etc.

[0145] Physical properties

[0146] The polypropylene composition produced by the method described herein can have a weight average molecular weight (MW) of about 50 kDa or greater as measured by GPC-DRI. The polypropylene composition can have a weight average molecular weight (MW) in the range of about 50 kDa to about 1 MDa, about 100 kDa to about 1 MDa, or about 100 kDa to about 900 kDa. w In any embodiment, the polypropylene composition produced using the present method may have a MWD (MWD) of about 10 or greater, about 15 or greater, or about 18 or greater as measured by GPC-DRI. w / M n ).

[0147] The polypropylene composition prepared by the present method may have a multimodal molecular weight distribution having more than one peak or inflection point, such as a high molecular weight tail. In any embodiment, the high molecular weight tail of the polypropylene composition has a z-average molecular weight (M) greater than about 300 kDa, greater than about 400 kDa, greater than about 500 kDa, or greater than about 800 kDa as measured by GPC-DRI. z ).

[0148] The polypropylene composition produced by the present method can have a melt flow rate at 230° C., 2.16 kg of 0.1 g / 10 min to 100 g / 10 min, 0.1 g / 10 min to 75 g / 10 min, 0.1 g / 10 min to 50 g / 10 min, or 1 g / 10 min to 50 g / 10 min, calculated according to ASTM 1238-20.

[0149] The polypropylene compositions disclosed herein may exhibit improved strain hardening as evidenced by an increased peak extensional viscosity. The polypropylene compositions disclosed herein may have a peak extensional viscosity (not annealed) at a strain rate of 1 / sec (190°C) greater than about 50 kPa·s, greater than about 55 kPa·s, greater than about 65 kPa·s, greater than about 75 kPa·s, or greater than about 100 kPa·s. The polypropylene composition may have a lower limit selected from any one of about 50 kPa·s, about 55 kPa·s, or about 60 kPa·s, to an upper limit of about 100 kPa·s, about 150 kPa·s, about 200 kPa·s, or about 250 kPa·s at a strain rate of 1 / sec (190°C), wherein any lower limit may be combined with any upper limit.

[0150] The polypropylene compositions disclosed herein may exhibit a strain hardening ratio of about 1.5 or greater, about 1.8 or greater, or about 2.0 or greater.

[0151] The polypropylene compositions disclosed herein may exhibit increased melt strength in the range of about 2.5 cN to about 100 cN, about 5 cN to about 100 cN, or about 10 cN to about 100 cN.

[0152] The polypropylene compositions disclosed herein may exhibit an ASTM D790A-20 flexural modulus of greater than about 1200, about 1400, or about 1500.

[0153] Embodiments disclosed herein include:

[0154] Embodiment A: A polymer composition comprising: a first polymer component comprising polypropylene; a second polymer component comprising a high molecular weight copolymer having a weight average molecular weight greater than about 1 MDa; wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190°C) greater than 55 kPa·s.

[0155] Embodiment B: A method comprising: preparing a polypropylene composition by a multi-stage polymerization, the multi-stage polymerization comprising a first stage to produce a propylene polymer and a second stage to produce a high molecular weight copolymer (which has a weight average molecular weight greater than about 1 MDa); wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190°C) greater than 55 kPa·s.

[0156] Embodiments A and B may have one or more of the following additional elements in any combination.

[0157] Element 1: wherein the second polymer component comprises a polypropylene copolymer.

[0158] Element 2: wherein the second polymer component comprises one or more comonomers selected from the group consisting of ethylene, propylene, butene, hexene, octene, butadiene, norbornene, ethylidene norbornene, vinyl norbornene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 1,6-octadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, and 1,11-dodecadiene.

[0159] Element 3: wherein the peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190° C.) is greater than 75 kPa·s.

[0160] Element 4: wherein the second polymer component is present in a weight percent (wt %) of the polymer composition of about 2 wt % or greater.

[0161] Element 5: wherein the polymer composition has a Mw / Mn of about 10.0 or greater.

[0162] Element 6: wherein the polymer composition has a melt strength in the range of 10 cN to 100 cN.

[0163] Element 7: Wherein the ASTM D790A flexural modulus is greater than about 1500.

[0164] Element 8: wherein the strain hardening ratio is about 1.5 or greater.

[0165] Element 9: wherein the second stage comprises a prepolymerization reactor.

[0166] Element 10: wherein the second stage comprises a slurry loop reactor.

[0167] Element 11: wherein the second stage comprises a gas phase polymerization reactor.

[0168] Element 12: wherein the first stage comprises a molar ratio of chain transfer agent to monomer reactants of from about 0 to about 0.5.

[0169] Element 13: wherein the high molecular weight copolymer comprises ethylene propylene copolymer.

[0170] Element 14: wherein the high molecular weight copolymer is present in a weight percent (wt %) of the polymer composition of about 2 wt % or greater.

[0171] Element 15: wherein the polypropylene composition has an ASTM D790A flexural modulus greater than about 1500.

[0172] Element 16: further comprising post-treating the polypropylene composition with a peroxide reagent.

[0173] Element 17. Wherein the polymer composition has a Mw / Mn of about 10.0 or greater.

[0174] By way of non-limiting example, example combinations suitable for A include, but are not limited to, 1 with any one or more of 2 to 8; 2 with any one or more of 1 and 3 to 8; 3 with any one or more of 1 to 2 and 4 to 8; 4 with any one or more of 1 to 3 and 5 to 8; 5 with any one or more of 1 to 4 and 6 to 8; 6 with any one or more of 1 to 5 and 7 to 8; 7 with any one or more of 1 to 6 and 8; 8 with any one or more of 1 to 7. Example combinations suitable for B include, but are not limited to, 9 with any one or more of 1 to 8 and 10 to 17; 10 with any one or more of 1 to 9 and 11 to 17; 11 with any one or more of 1 to 10 and 12 to 17; 12 with any one or more of 1 to 11 and 13 to 17; 13 with any one or more of 1 to 12 and 14 to 17; 14 with any one or more of 1 to 13 and 15 to 17; 15 with any one or more of 1 to 14 and 16 to 17; 16 with any one or more of 1 to 15 and 17; 17 with any one or more of 1 to 16;

[0175] In order to facilitate a better understanding of the present disclosure, the following examples of preferred or representative embodiments are provided. The following examples should in no way be construed as limiting or defining the scope of the invention.

[0176] Example

[0177] In the following examples, polymerization conditions were used for several polypropylene compositions in order to vary the proportion of the high MW tail.

[0178] Comparative Example 1: Effect of MFR on the proportion of high MW tail

[0179] In the following comparative example, polypropylene with high MW was produced by combining Z / N 168 catalyst with F donor to produce PP with broad MWD and high molecular tail. The samples were produced in a continuous stirred tank reactor (CSTR) under pilot plant conditions. A magnesium chloride supported titanium catalyst commercially sold as Avant ZN-168M was used in an external donor blend of propyltriethoxysilane and dicyclopentyldimethoxysilane.

[0180] The catalyst composition preparation is carried out continuously by contacting the catalyst solid, triethylaluminum and an external electron donor system under conditions known in the art to produce an active, stereospecific catalyst for propylene polymerization. The activated catalyst is continuously sent to a prepolymerization reactor, where it is polymerized in propylene to a productivity of about 100 to 300 grams-polymer / gram-catalyst. The prepolymerized catalyst is then continuously sent to a continuous stirred tank reactor and polymerization is continued at a reactor temperature of 70°C to produce a homopolymer. Hydrogen is supplied as a chain transfer agent. The reactor slurry is continuously removed from the polymerization reactor and homopolymer pellets are continuously separated from the liquid propylene. The pellets are passed through a dryer to remove residual monomers and collected in a Gaylord box.

[0181] The fractions of the high MW tail are summarized in Table 1. The corresponding molecular weight distribution is also graphically represented as the relative mass fraction versus log molecular weight in Figure 4 middle.

[0182]

[0183]

[0184] As the comparative results show, although the combination of catalyst and donor produces a broad and bimodal MWD, the concentration of the high MW tail decreases as the concentration of chain transfer agent decreases and the MFR of PP increases.

[0185] Example 1: Multi-stage polymerization of a polypropylene composition

[0186] In the following example, a polypropylene composition according to the present disclosure is produced in a multistage polymerization having a first stage containing a series of slurry loop reactors producing polypropylene polymers, followed by a second stage having a series of gas phase reactors producing a high MW tail. In this example, the high MW tail is produced by a mixture of propylene and ethylene comonomers. The process conditions used in this example are provided in Tables 2A-2B below.

[0187]

[0188]

[0189] For comparative sample C1, no additional high MW tail was added. For comparative samples C2 and C3, additional high MW tail was added via a separate reactor. For exemplary samples E1-E3 prepared according to the present disclosure, additional high MW tail was added via the addition of ethylene via a separate reactor.

[0190] As shown, the additional ethylene monomer has a higher reactivity with the selected catalyst, in addition to leading to M z In addition to the increase, it also leads to an increase in the fraction of the high MW tail.

[0191] The formulation data are shown in Table 2B, while the molecular weight data are provided in Table 2C. The corresponding molecular weight distribution is also graphically represented as the relative mass fraction versus log molecular weight in Figure 5 In the figure, the increasing fraction of high MW tail is shown for E1-E3.

[0192]

[0193]

[0194] Example 2: Bimodal high melt strength polypropylene with strain hardening

[0195] In the following examples, additional polymers were examined, including additional polymers produced using a THC-133 titanium catalyst type containing a phthalate internal electron donor and methylcyclohexyldimethoxysilane as an internal electron donor. The process conditions are shown in Tables 3A and 3B below.

[0196]

[0197]

[0198] The results are shown in Tables 3C to 3E, which also show the change in extensional viscosity over time for E4, showing an enhanced entanglement response, which is indicative of a high MW tail fraction.

[0199]

[0200]

[0201]

[0202] Example 3: Bimodal high melt strength polypropylene with strain hardening

[0203] In the following examples, extensional viscosity is analyzed for C15, a comparative sample prepared using a catalyst associated with increased high MW tail production. Sample E6 was produced in accordance with the present disclosure using the same catalyst as C15, but in a multi-stage polymerization process in which ethylene was introduced in a second stage gas phase polymerization to which ethylene was added. E7 was prepared similarly to E6, but using a titanium catalyst. Table 4 shows the properties measured in Example 3.

[0204]

[0205] The results are plotted in Figure 7-9 , which shows the change in elongational viscosity of each sample over time. Figure 7 The results for C15 are illustrated, showing a lack of strain hardening properties and extensional viscosity associated with low entanglement behavior. Figure 8 Explain the results of E6 and Fig. 9 The results for E7 are illustrated, both of which show enhanced strain hardening and entanglement behavior, indicating an increased concentration of high MW tails.

[0206] Therefore, the disclosed systems and methods are well adapted to achieve the mentioned purposes and advantages and those inherent therein. The specific embodiments disclosed above are illustrative only, because the teachings of the present disclosure can be implemented and modified in different but equivalent ways that are obvious to those skilled in the art who benefit from the teachings herein. In addition, except as described in the claims below, it is not intended to limit the details of the construction or design shown herein. It is therefore obvious that the specific illustrative embodiments disclosed above can be changed, combined or modified, and all such variations are considered to be within the scope of the present disclosure. The systems and methods disclosed herein illustratively can be appropriately implemented in the absence of any element not specifically disclosed herein and / or any optional element disclosed herein. Although compositions and methods are described with the wording "comprising", "containing" or "including" various components or steps, compositions and methods can also be "essentially composed of various components and steps" or "composed of various components and steps". All numbers and ranges disclosed above can vary to some extent. Whenever a numerical value with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. In particular, each range of values ​​disclosed herein (in the following format, "about a to about b," or equivalently, "about a to b," or equivalently, "about ab") should be understood to list all numbers and ranges contained within the broader range of values. In addition, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. In addition, the indefinite articles "a" or "an" used in the claims are defined herein to mean one or more than one of the elements they introduce. If there is any conflict in the use of a word or term in this specification and one or more patents or other documents incorporated herein by reference, the definition consistent with this specification shall be adopted.

[0207] As used herein, the phrase "at least one" preceding a series of items, as well as the terms "and" or "or" separating any item, modifies the entire list, rather than the individual members (i.e., items) of the list. The phrase "at least one" is permitted to include the following meanings: at least one of any one of the items, and / or at least one of any combination of the items, and / or at least one of each of the items. For example, the term "at least one of A, B, and C" or "at least one of A, B, or C" each refers to only A, only B, or only C; any combination of A, B, and C; and / or at least one of each of A, B, and C.

[0208] Directional terms such as above, below, up, down, upward, downward, left, right, etc. are used in connection with the illustrative embodiments as they are described in the figures, with the upward direction being towards the top of the corresponding figure and the downward direction being towards the bottom of the corresponding figure.

Claims

1. A polymer composition comprising: a first polymer component comprising polypropylene; a second polymer component comprising a high molecular weight copolymer having a weight average molecular weight greater than about 1 MDa; Wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190° C.) greater than 55 kPa·s.

2. The polymer composition of claim 1, wherein the second polymer component comprises a polypropylene copolymer.

3. The polymer composition of any preceding claim, wherein the second polymer component comprises one or more comonomers selected from one or more of the following: ethylene, propylene, butene, hexene, octene, butadiene, norbornene, ethylidene norbornene, vinyl norbornene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 1,6-octadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, and 1,11-dodecadiene.

4. A polymer composition according to any preceding claim, wherein the peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190°C) is greater than 75 kPa·s.

5. The polymer composition of any preceding claim, wherein the second polymer component is present in an amount of about 2 wt% or greater of the polymer composition.

6. A polymer composition according to any preceding claim, wherein the polymer composition has an M of about 10.0 or greater. w / M n .

7. A polymer composition according to any preceding claim, wherein the polymer composition has a melt strength in the range of 10 cN to 100 cN.

8. The polymer composition of any preceding claim, wherein the polymer composition has an ASTM D790A flexural modulus greater than about 1500.

9. The polymer composition of any preceding claim, wherein the strain hardening ratio is about 1.5 or greater.

10. The polymer composition of any preceding claim, wherein the polymer composition has an M of about 10.0 or greater. w / M n .

11. Methods, comprising: The polypropylene composition is prepared by a multi-stage polymerization comprising: a first stage producing a propylene polymer, and a second stage of producing a high molecular weight copolymer having a weight average molecular weight greater than about 1 MDa; Wherein the polymer composition has a peak extensional viscosity (unannealed) at a strain rate of 1 / sec (190° C.) greater than 55 kPa·s.

12. The process according to claim 11, wherein the second stage comprises a prepolymerization reactor.

13. A process according to claims 11 and 12, wherein the second stage comprises a slurry loop reactor.

14. The process according to claims 11-13, wherein the second stage comprises a gas phase polymerization reactor.

15. The method of claims 11-14, wherein the first stage comprises a molar ratio of chain transfer agent to monomer reactants of from about 0 to about 0.

5.

16. The method of claims 11-15, wherein the high molecular weight copolymer comprises one or more comonomers selected from one or more of the following: ethylene, propylene, butene, hexene, octene, butadiene, norbornene, ethylidene norbornene, vinyl norbornene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 1,6-octadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene. The method of claim 1, wherein the second monomer is ethylene.

17. The method of claims 11-16, wherein the high molecular weight copolymer comprises ethylene propylene copolymer.

18. The method of claims 11-17, wherein the high molecular weight copolymer is present in an amount of about 2 wt% or greater of the polymer composition.

19. The method of claims 11-18, wherein the polypropylene composition has an ASTM D790A flexural modulus greater than about 1500.

20. The method of claims 11-19, further comprising post-treating the polypropylene composition with a peroxide reagent.

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