Catalyst Composition for Polyolefin Polymers

Abstract

A Ziegler-Natta catalyst composition is disclosed. The catalyst composition is formed from a procatalyst containing a magnesium moiety and a titanium moiety. At least one internal electron donor is incorporated into the procatalyst. During the titanation procedure in combination with the internal electron donor, a titanium extractant is used to remove or deactivate less active or atactic titanium active sites.

Description

[Technical Field]

[0001] (Related Applications) This application is based on and claims priority to U.S. Provisional Patent Application No. 62 / 902,118, filed September 18, 2019, which is incorporated herein by reference. [Background technology]

[0002] Polyolefin polymers are used in many different applications and fields. Polyolefin polymers are, for example, thermoplastic polymers that can be easily processed. Polyolefin polymers can also be recycled and reused. Polyolefin polymers are formed from hydrocarbons such as ethylene and alpha-olefins, which are obtained from petrochemicals and are abundantly available.

[0003] Polypropylene polymers, a type of polyolefin polymer, generally have a linear structure based on propylene monomers. Polypropylene polymers can have a variety of different stereospecific configurations. For example, polypropylene polymers can be isotactic, syndiotactic, and atactic. Isotactic polypropylene is perhaps the most common form and can be highly crystalline. Polypropylene polymers that can be produced include homopolymers, modified polypropylene polymers, and polypropylene copolymers, including polypropylene terpolymers. By modifying polypropylene or copolymerizing propylene with other monomers, a variety of different polymers can be produced with properties desired for specific applications. For example, polypropylene copolymers can be produced with elastomeric properties that significantly improve the impact strength of the polymer.

[0004] The global demand for olefin-based polymers continues to grow as applications for these polymers become more diverse and sophisticated. Ziegler-Natta catalyst compositions for the production of olefin-based polymers are known. Ziegler-Natta catalyst compositions typically include a procatalyst containing a transition metal halide (i.e., titanium, chromium, or vanadium) and a cocatalyst such as an organoaluminum compound.

[0005] Ziegler-Natta catalyst compositions are made using an organic electron donor. The electron donor is typically referred to as an internal electron donor to indicate that it is attached to the procatalyst and to distinguish it from other electron donors used during the polymerization process, which are typically referred to as external electron donors. The internal electron donor can significantly determine the performance characteristics, such as catalytic activity, of the overall catalyst composition. The internal electron donor can also affect the properties of the polymer made from the catalyst composition. For example, the internal electron donor can affect the polymer's melt flow rate, xylene solubles content, etc.

[0006] In addition to the internal electron donor incorporated into the procatalyst, the method of producing the procatalyst can also affect a range of performance characteristics. For example, varying the stoichiometry of the raw materials used to produce the procatalyst, as well as the conditions and number of steps used during synthesis, can affect various properties of the catalyst composition and the properties of the produced polymer.

[0007] Recently, great efforts have been made to improve the performance of catalyst compositions by using internal electron donors with relatively complex structures. Although great progress has been made in the art, various improvements are still needed. For example, there is a need for catalyst compositions that can produce polyolefin polymers with a wide range of xylene soluble content, for example, polymers with relatively high xylene soluble content and polymers with relatively low xylene soluble content. In addition to the above, there is also a need for a process for producing a catalyst composition that not only improves the properties of the catalyst composition but also minimizes the amount of internal electron donor required to produce the catalyst composition. Summary of the Invention

[0008] In general, the present disclosure is directed to catalyst systems for producing polyolefin polymers. The present disclosure is also directed to improved catalyst compositions and processes for producing the catalyst compositions. The catalyst compositions of the present disclosure can have many benefits and can be designed and formulated for specific applications. For example, Ziegler-Natta catalyst compositions made according to the present disclosure can have increased stereoselectivity and / or can produce polyolefin polymers with a very wide range of xylene solubles content. Thus, the catalyst compositions of the present disclosure are well suited for use in many different types of polymerization processes to produce a wide range of different polyolefin products. The catalyst compositions can produce polymers, such as propylene polymers, with reduced amorphous or atactic phase and reduced xylene solubles content. Among other advantages, catalyst compositions can be made according to the present disclosure that have the above benefits while also requiring less internal electron donor to produce the catalyst composition.

[0009] In some embodiments, for example, the present disclosure is directed to a process for producing a Ziegler-Natta catalyst composition, the process including forming a procatalyst support from a magnesium portion and a titanium portion. For example, the magnesium moiety may have the formula: Mg(OR)nX 2-n Lm where R comprises an alkyl or aryl group containing a halogen atom, n is 0 to 2, L comprises an ether and / or alcohol coordinated ligand group, and m is the number of coordinated ligands and is 0 to 10. The titanium moiety may have the following formula: Ti(OR) g X 4-g where each R is independently a C1-C4 alkyl group; X is bromine, chlorine, or iodine; and g is 0, 1, 2, or 3.

[0010] The procatalyst is subjected to at least a first titanation step and a second titanation step. An internal electron donor, such as an aryl diester, can be incorporated into the procatalyst. According to the present disclosure, the procatalyst is contacted with a titanium extractant during or after at least one titanation step. The titanium extractant removes titanium from the procatalyst. More specifically, it is believed that the titanium extractant can extract or deactivate titanium species on the procatalyst that are less active or are atactic sites that do not bind to the internal electron donor, thereby improving the stereoselectivity of the catalyst.

[0011] The titanium extractant may be less sterically bulky than the internal donor used in preparing the procatalyst, allowing the titanium extractant to access titanium sites inaccessible by the sterically bulky internal donor. The titanium extractant exhibits an affinity for titanium that is equal to or less than that of the internal donor used in preparing the procatalyst. A small amount of titanium extractant may remain in the procatalyst. Examples of titanium extractants include esters, ketones, carbonates, and mixtures thereof. In one aspect, the titanium extractant is a monoester. For example, the titanium extractant may be an alkyl benzoate, such as ethyl benzoate.

[0012] The internal electron donor can also vary depending on the particular application. In one aspect, the internal electron donor is an aryl diester. The internal electron donor has the following formula: [ka] wherein R1 and R4 are each hydrogen or a hydrocarbyl group having 1 to 20 carbon atoms; at least one of R2 and R3 is hydrogen; at least one of R2 and R3 comprises a substituted or unsubstituted hydrocarbyl group having 1 to 20 carbon atoms; E1 and E2 are the same or different and are selected from the group consisting of alkyl having 1 to 20 carbon atoms, optionally containing heteroatoms, substituted alkyl having 1 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, substituted aryl having 6 to 20 carbon atoms, or an inert functional group having 1 to 20 carbon atoms; X1 and X2 are each O, S, an alkyl group, or NR5; and R5 is a hydrocarbyl group having 1 to 20 carbon atoms or hydrogen.

[0013] Alternatively, the internal electron donor can be a naphthyl dibenzoate, such as a 1,8-naphthyl diaryloate compound, as follows: [ka] wherein each R is independently hydrogen, halogen, alkyl having 1 to about 8 carbon atoms, phenyl, arylalkyl having 7 to about 18 carbon atoms, or alkylaryl having 7 to about 18 carbon atoms. In another embodiment, each R is independently hydrogen, alkyl having 1 to about 6 carbon atoms, phenyl, arylalkyl having 7 to about 12 carbon atoms, or alkylaryl having 7 to about 12 carbon atoms.

[0014] Common examples include 1,8-naphthyldi(alkylbenzoates), 1,8-naphthyldi(dialkylbenzoates), 1,8-naphthyldi(trialkylbenzoates), 1,8-naphthyldi(arylbenzoates), 1,8-naphthyldi(halobenzoates), 1,8-naphthyldi(dihalobenzoates), 1,8-naphthyldi(alkylhalobenzoates), and the like.

[0015] As described above, the titanium extractant can be contacted with the procatalyst during the titanation step. For example, the titanium extractant can be contacted with the procatalyst during the first titanation step, the second titanation step, the third titanation step, or any combination thereof. For example, the procatalyst can be contacted with the titanium extractant only during the second titanation step. The procatalyst can be contacted with the titanium extractant alone or in combination with an internal electron donor. For example, the procatalyst can be contacted with the internal electron donor in the absence of a titanium extractant during the first titanation step, and with the titanium extractant in the absence of an internal electron donor during the second titanation step. In another alternative, the procatalyst can be contacted with the internal electron donor and the titanium extractant during the first titanation step, and with the internal electron donor, the titanium extractant, or both the internal electron donor and the titanium extractant during the second titanation step.

[0016] The procatalyst may include magnesium and titanium halide compounds. In one aspect, the procatalyst is a spray-crystallized magnesium halide compound.

[0017] The present disclosure is also directed to a process for producing a polyolefin polymer. The process comprises polymerizing propylene monomer and, optionally, one or more comonomers in the presence of a catalyst composition. The catalyst composition may comprise a procatalyst that has been subjected to at least a first titanation step and a second titanation step. According to the present disclosure, the procatalyst is contacted with a titanium extractant during or after at least one of the titanation steps.

[0018] The process for producing polyolefin polymers as described above can produce polypropylene polymers having a wide range of xylene solubles contents. For example, the xylene solubles content can be anywhere from about 0.25% by weight to about 10% by weight. In this manner, the catalyst composition of the present disclosure is well suited for producing all different types of polyolefin polymers. In some embodiments, polypropylene polymers can be produced having a relatively low xylene solubles content, for example, less than about 4% by weight. However, in other embodiments, polypropylene polymers having a higher xylene solubles content can be produced.

[0019] When used to produce polyolefin polymers, the catalyst composition may include a cocatalyst. The cocatalyst may include a hydrocarbon aluminum compound such as triethylaluminum. The composition may also include a selectivity control agent. The selectivity control agent may include an alkoxysilane. For example, the selectivity control agent can include dicyclopentyldimethoxysilane, di-tert-butyldimethoxysilane, methylcyclohexyldimethoxysilane, methylcyclohexyldiethoxysilane, ethylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, di-n-propyldimethoxysilane, diisobutyldimethoxysilane, diisobutyldiethoxysilane, isobutylisopropyldimethoxysilane, di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, diethylaminotriethoxysilane, cyclopentylpyrrolidinodimethoxysilane, bis(pyrrolidino)dimethoxysilane, bis(perhydroisoquinolino)dimethoxysilane, dimethyldimethoxysilane, or a mixture thereof.

[0020] In yet another embodiment, the catalyst composition may include an activity limiting agent.

[0021] Other features and aspects of the disclosure are discussed in more detail below. [Brief explanation of the drawings]

[0022] A full and enabling disclosure of the present disclosure is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which: [Figure 1] 1 is a graphical representation of the results obtained in the following examples. [Figure 2] 1 is another graphical representation of the results obtained in the examples below.

[0023] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Those skilled in the art will appreciate that this discussion is a description of exemplary embodiments only and is not intended to limit the broader aspects of the present disclosure.

[0025] In general, the present disclosure is directed to catalyst systems for producing polyolefin polymers, particularly polypropylene polymers. The present disclosure also is directed to catalyst compositions and methods for polymerizing and copolymerizing olefins using the catalyst compositions. Generally, the catalyst compositions of the present disclosure include a procatalyst containing a magnesium moiety, an optional titanium moiety, and an internal electron donor. According to the present disclosure, the procatalyst is produced using a titanium extractant. The titanium extractant extracts or deactivates titanium species that are less active and have poor stereoregulating ability than other titanium species present on the catalyst. Using the titanium extractant to remove undesired titanium species produces a Ziegler-Natta catalyst composition with increased stereoselectivity and improved XS capability.

[0026] Such catalyst compositions can produce polymers with a desired combination of properties. For example, the catalyst compositions of the present disclosure can be used to produce polyolefin polymers with a wide range of xylene solubles content. As a result, a single catalyst can be used to produce polymers with low xylene solubles content and polymers with relatively high xylene solubles content. As a result, the catalyst products can produce polymers with a wide range of properties without requiring catalyst transitions when changing from one polymer grade to another. For example, polyolefin polymers, such as polypropylene polymers, produced using a single catalyst made according to the present disclosure can have a xylene solubles content ranging from 1.5% to 6%.

[0027] In one aspect, the procatalyst composition can also be produced at the expense of less internal electron donor in the titanation process. For example, in one aspect, the titanium extractant can remove or replace titanium that cannot be easily replaced by a more expensive internal electron donor. Furthermore, while the procatalyst is produced using less internal electron donor, the same amount of internal electron donor can still be incorporated into the procatalyst as would occur if no titanium extractant were used.

[0028] The synthesis of a procatalyst composition according to the present disclosure generally involves two or more titanation reactions or steps. For example, a procatalyst composition can be produced using two, three, or four titanation steps. In accordance with the present disclosure, as described in more detail below, a titanium extractant of the present disclosure can be contacted with the procatalyst during the synthesis of the procatalyst composition during any or all of the titanation steps. The titanium extractant can also be contacted with the procatalyst after the titanation step has been performed. The titanium extractant can also be contacted with the procatalyst during the titanation step, either alone or in combination with an internal electron donor.

[0029] The procatalyst used to produce the catalyst composition of the present disclosure can vary depending on the particular embodiment and desired results. Generally, the procatalyst support contains a magnesium moiety and a titanium moiety. For example, the magnesium moiety generally has the following formula: Mg(OR)nX 2-n Lm where R comprises an alkyl or aryl group containing a halogen atom, n is 0 to 2, L comprises an ether and / or alcohol coordinated ligand group, and m is the number of coordinated ligands and is 0 to 10. The titanium moiety generally has the following formula: Ti(OR) g X 4-g where each R is independently a C1-C4 alkyl group; X is bromine, chlorine, or iodine; and g is 0, 1, 2, or 3.

[0030] The procatalyst support can be, for example, a mixed magnesium titanium compound (MagTi) or a benzoate-containing magnesium chloride compound (BenMag).

[0031] In one embodiment, the procatalyst support is a mixed magnesium / titanium compound ("MagTi"). A "MagTi precursor" is a compound of the formula Mg d Ti(OR e ) f X g wherein Re is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms, or COR', and R' is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms, and each OR eThe groups may be the same or different, X is independently chlorine, bromine, or iodine, preferably chlorine, d is 0.5 to 56, or 2 to 4, f is 2 to 116, or 5 to 15, and g is 0.5 to 116, or 1 to 3. The precursor is prepared by controlled precipitation, removing alcohol from the reaction mixture used in its preparation. The reaction medium may comprise a mixture of an aromatic liquid, particularly a chlorinated aromatic compound, most particularly chlorobenzene, with an alkanol, particularly ethanol. Suitable halogenating agents include titanium tetrabromide, titanium tetrachloride, or titanium trichloride, particularly titanium tetrachloride. Removal of the alkanol from the solution used in the halogenation precipitates a solid precursor, which has a particularly desirable shape and surface area. Furthermore, the resulting precursor has a particularly uniform particle size.

[0032] Alternatively, the procatalyst support is a benzoate-containing magnesium chloride material ("BenMag"). As used herein, "benzoate-containing magnesium chloride" ("BenMag") refers to a procatalyst containing a benzoate internal electron donor (i.e., a halogenated procatalyst support). The BenMag material may also contain titanium moieties, such as titanium halides. The benzoate internal donor is unstable and may be replaced by other electron donors during catalyst and / or procatalyst synthesis. Non-limiting examples of suitable benzoate groups include ethyl benzoate, methyl benzoate, ethyl p-methoxybenzoate, methyl p-ethoxybenzoate, ethyl p-ethoxybenzoate, and ethyl p-chlorobenzoate. In some embodiments, the benzoate group is ethyl benzoate. In one embodiment, the BenMag procatalyst support may be the product of halogenation of any procatalyst support (i.e., a MagMo precursor or a MagTi precursor) in the presence of a benzoate compound.

[0033] In one embodiment, substantially spherical MgCl 2-The nEtOH adduct can be formed by a spray crystallization process. In this process, a MgCl-nROH melt, where n is 1-6, is sprayed inside a vessel while an inert gas is introduced into the upper part of the vessel at a temperature of 20-80°C. The melt droplets are transferred to a crystallization zone where an inert gas is introduced at a temperature of -50-20°C, crystallizing the melt droplets into spherical, non-agglomerated solid particles. The spherical MgCl particles are then classified into desired sizes. Particles of undesired sizes can be recycled. The spherical MgCl precursor has an average particle size (Malvern diameter) of about 15-150 microns, preferably 20-100 microns, and most preferably 35-85 microns. 50 ).

[0034] The spherical procatalyst support described above is referred to as a "spray-crystallized" procatalyst precursor. In some embodiments, the spray-crystallized precursor can be dealcoholized. For example, the spray-crystallization process can be subjected to a post-treatment process to remove ethanol. For example, the ethanol / magnesium chloride weight ratio can be less than about 6:1, such as from about 1.5:1 to about 3.1:1, for example, from about 2:1 to about 2.5:1.

[0035] According to the present disclosure, one of the above procatalyst supports may be subjected to multiple titanation steps in forming the procatalyst, and then subsequently activated by contact with a cocatalyst. During titanation, the procatalyst is contacted with a titanium halogenating agent capable of converting the magnesium moiety to a magnesium halide and / or the titanium moiety to a titanium halide.

[0036] In one embodiment, the titanium halide has the formula Ti(OR e ) f X h wherein R e is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms, or COR', where R' is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms, and each OR eThe groups may be the same or different, X is independently chlorine, bromine, or iodine, f is an integer from 0 to 3, h is an integer from 1 to 4, and f + h is 4. The halogenating agent may be TiCl4. The titanation may be carried out in the presence of a chlorinated or non-chlorinated aromatic liquid, such as dichlorobenzene, o-chlorotoluene, chlorobenzene, benzene, toluene, or xylene. For example, the titanation may be carried out using a mixture of a titanium halide and a chlorinated aromatic liquid, containing 40 to 60 volume percent titanium halide, such as TiCl4.

[0037] The procatalyst and titanium halide can be initially contacted at a temperature below about 10° C., such as below about 0° C., such as below about −10° C., such as below about −20° C., such as below about −30° C. The initial temperature is generally greater than about −50° C., such as greater than about −40° C. The mixture is then heated at a rate of 0.1 to 10.0° C. / min, or at a rate of 1.0 to 5.0° C. / min. The temperature for titanation is from 40° C. to 150° C. (or any value or subrange therebetween), alternatively from 0° C. to 120° C.

[0038] The titanation procedure can be repeated one, two, three, four, or more times as needed. In the past, internal electron donors were incorporated into the procatalyst by their presence during the titanation step. Indeed, when incorporating an internal electron donor, such as an aryl diester, into the procatalyst, it was believed that the internal electron donor's presence during many, if not all, titanation steps was necessary to produce a catalyst composition with the high activity necessary for polymerization and to produce a polymer with low xylene solubles. However, these internal electron donors are relatively expensive and have not been efficiently incorporated into the procatalyst through the process. It is believed, although unknown, that the procatalyst contains titanium species that bind to sites that are less active and not readily available for binding with the internal electron donor. Therefore, the present disclosure is directed to the use of a titanium extractant during the process to remove less active titanium without interfering with the incorporation of the internal electron donor into the procatalyst. Indeed, in one aspect, the process of the present disclosure can more efficiently incorporate the internal electron donor into the procatalyst, thereby using less internal electron donor and improving the economics of the synthesis process.

[0039] According to the present disclosure, the procatalyst is contacted with at least one internal electron donor and a titanium extractant during and / or after the titanation step. The method of contacting the procatalyst, titanium halide, internal electron donor, and titanium extractant can vary depending on the particular application and desired results. In some embodiments, for example, the procatalyst can be contacted with the internal electron donor in combination with a titanium halide during one or more titanation steps, while the procatalyst can be contacted with the titanium extractant and titanium halide during other titanation steps. Alternatively, the internal electron donor and titanium extractant can be contacted with the procatalyst in combination with a titanium halide during any or all of the titanation steps. In still other embodiments, the procatalyst can be contacted with the internal electron donor during certain titanation steps, with the titanium extractant during other titanation steps, and with both the internal electron donor and the titanium extractant during further titanation steps.

[0040] For example, in one embodiment, the procatalyst is contacted only with the internal electron donor in the presence of a titanium halide during the first titanation step and only with the titanium extractant in combination with the titanium halide during the second titanation step. In alternative processes, the procatalyst is contacted with the internal electron donor and the titanium extractant during the first titanation step and only with the titanium extractant during the second titanation step, or only with the internal electron donor during the second titanation step, or with both the internal electron donor and the titanium extractant during the second titanation step.

[0041] It should be understood that various other modifications of the process can be made to produce a catalyst composition having a desired amount of catalytic activity and a desired level of stereoselectivity. For example, the process can be carried out so that the procatalyst is contacted with a titanium extractant in the absence of an internal electron donor during at least one of the titanation steps. The process can also be carried out so that the procatalyst is contacted with both an internal electron donor and a titanium extractant during at least one of the titanation steps.

[0042] The method of contacting the procatalyst, titanium halide, internal electron donor, and titanium extractant can vary. For example, in some embodiments, the procatalyst can first be contacted with the titanium halide and, optionally, an aromatic compound, such as a chlorinated aromatic compound. The resulting mixture can be stirred and, if necessary, heated. The internal electron donor and / or titanium extractant can then be added to the reaction mixture to produce a solid procatalyst component.

[0043] Alternatively, the procatalyst can be contacted with an internal electron donor and / or a titanium extractant prior to reaction with the titanium halide.

[0044] In yet another embodiment, the catalyst may be contacted simultaneously with the titanium halide, the internal electron donor and / or the titanium extractant during one of the titanation steps.

[0045] The contact time between the procatalyst and the internal electron donor and / or titanium extractant can also vary. Generally, the contact time between the procatalyst and other components is at least 10 minutes, such as at least 15 minutes, for example at least 20 minutes, for example at least 40 minutes, such as at least 1 hour, at a temperature of at least about −40° C., such as at least about −30° C., for example at least about −20° C., and generally less than about 150° C., such as less than about 120° C., for example less than about 110° C., for example less than about 100° C., for example less than about 80° C., for example less than about 50° C.

[0046] After multiple titanation steps, a solid procatalyst component is produced.

[0047] After the aforementioned titanation procedure, the resulting solid procatalyst composition is separated from the reaction medium used in the final process by filtration, for example, to produce a wet filter cake. The wet filter cake can then be rinsed or washed with a liquid diluent to remove unreacted titanium halide and, if necessary, dried to remove residual liquid. Typically, the resulting solid procatalyst composition is washed one or more times with a "wash liquid," which is a liquid hydrocarbon, such as an aliphatic hydrocarbon, such as isopentane, isooctane, isohexane, hexane, pentane, or octane. The solid procatalyst composition can then be separated and dried or slurried in a hydrocarbon, particularly a relatively heavy hydrocarbon, such as mineral oil, for further storage or use.

[0048] After recovering the solid procatalyst, the procatalyst composition can optionally be contacted with an additional amount of a titanium halide compound. After the titanation step, for example, the solid procatalyst can also be contacted with one or more internal electron donors and / or one or more titanium extractants. For example, the solid procatalyst can be contacted with an additional amount of the internal electron donor, followed by an additional amount of the titanium extractant. In post-titanation processes, the procatalyst can also be simultaneously contacted with various other liquid components, such as acid chlorides. The procatalyst composition can be rinsed, washed, heat-treated, etc.

[0049] In some embodiments, after the titanation step, the solid procatalyst composition can be contacted with an internal electron donor and / or titanium extractant at elevated temperatures, such as above about 100°C, e.g., above about 110°C, and generally below about 170°C, e.g., below about 150°C, e.g., below about 130°C, while heating.

[0050] Through the above process, the internal electron donor and titanium extractant work together to produce a procatalyst composition with increased stereoselectivity. Additionally, in some embodiments, the resulting catalyst composition may also have increased or prolonged catalytic activity. The titanium extractant removes or displaces less active titanium species that may adversely affect the stereoregularity of the catalyst composition during polymerization. Additionally, the titanium extractant has been found not to significantly displace the internal electron donor, which, in some embodiments, can actually improve the efficiency of incorporation of the internal electron donor into the procatalyst composition.

[0051] During the process of producing the procatalyst, the titanium extractant removes undesired titanium species and is not itself significantly incorporated into the procatalyst composition. For example, the resulting procatalyst composition generally contains titanium extractant in an amount less than about 7 wt%, e.g., less than about 4 wt%, e.g., less than about 3 wt%, e.g., less than about 2 wt%, e.g., less than about 1 wt%. In one embodiment, the titanium extractant is incorporated into the procatalyst in an amount less than the internal electron donor on a weight percent basis. The titanium extractant removes a significant amount of titanium from the procatalyst. For example, during the process, the titanium extractant can remove more than about 10 wt%, e.g., more than about 15 wt%, e.g., more than about 20 wt%, e.g., more than about 25 wt%, e.g., more than about 30 wt%, e.g., more than about 35 wt%, e.g., more than about 40 wt%, e.g., more than about 45 wt%, e.g., more than about 50 wt% of the titanium present. Generally, the titanium loss is less than about 70 wt%, e.g., less than about 50 wt%, e.g., less than about 45 wt%.

[0052] The weight ratio of titanium to magnesium in the solid procatalyst composition is suitably from about 1:3 to about 1:160, or from about 1:4 to about 1:50, or from about 1:6 to 1:30. In one embodiment, the internal electron donor may be present in the procatalyst composition in a molar ratio of internal electron donor to magnesium of from about 0.005:1 to about 1:1, or from about 0.01:1 to about 0.4:1. Weight percentages are based on the total weight of the procatalyst composition.

[0053] Generally, the titanium extractant can be a compound that is less bulky and generally smaller than the internal electron donor. Titanium extractants that can be used include, for example, esters, ketones, carbonates, and mixtures thereof. In some embodiments, the titanium extractant can be a monoester. For example, the titanium extractant can be represented by the following formula: [ka] where R' comprises an alkyl group, a cyclic group, an aryl group having 1 to 20 carbon atoms, a heteroatom, or a combination thereof; and R" comprises hydrogen or one or more substituents, each of which may independently comprise an alkyl group, a cyclic group, an aryl group having 1 to 20 carbon atoms, a heteroatom, or a combination thereof. For example, in one embodiment, the supporting electron donor comprises ethyl benzoate.

[0054] Other monoesters that can be used as titanium extractants include carboxylic acid esters. Examples of such esters include methyl benzoate, ethyl benzoate, phenyl benzoate, ethyl anisate, benzyl acetate, ethyl acetate, octyl acetate, ethyl proprionate, ethyl butyrate, methyl butyrate, methyl laurate, methyl valerate, pentyl valerate, ethyl hexanoate, and mixtures thereof. Ketones that can be used include methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, acetone, diethyl ketone, ethyl phenyl ketone, butyl phenyl ketone, 3-hexanone, and mixtures thereof. Carbonates that can be used include dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, and mixtures thereof.

[0055] Internal electron donors that can be used with the disclosed process include those that preferentially bind to the active sites on the procatalyst compared to the titanium extractant. The internal electron donor can be, for example, an aryl diester, an amidophenol dibenzoate, a mercaptophenol dibenzoate, a naphthyl dibenzoate, or the like.

[0056] As used herein, an internal electron donor is a compound added during the formation of a catalyst composition that donates a pair of electrons to one or more metals present in the resulting composition. The internal electron donor is believed to help regulate the formation of active sites, thus enhancing the stereoselectivity of the catalyst. In some embodiments, the internal electron donor of the present disclosure has the following chemical formula: [ka] wherein R1 and R4 are each hydrogen or a hydrocarbyl group having 1 to 20 carbon atoms; at least one of R2 and R3 is hydrogen; at least one of R2 and R3 comprises a substituted or unsubstituted hydrocarbyl group having 1 to 20 carbon atoms; E1 and E2 are the same or different and are selected from the group consisting of alkyl having 1 to 20 carbon atoms, optionally containing heteroatoms, substituted alkyl having 1 to 20 carbon atoms (including cycloalkyl groups having 5 to 10 carbon atoms), aryl having 6 to 20 carbon atoms, substituted aryl having 6 to 20 carbon atoms, or an inert functional group having 1 to 20 carbon atoms; X1 and X2 are each O, S, an alkyl group, or NR5; and R5 is a hydrocarbyl group having 1 to 20 carbon atoms or hydrogen.

[0057] As used herein, the terms "hydrocarbyl" and "hydrocarbon" refer to substituents containing only hydrogen and carbon atoms, including branched or unbranched, saturated or unsaturated, cyclic, polycyclic, fused, or acyclic species, and combinations thereof. Non-limiting examples of hydrocarbyl groups include alkyl, cycloalkyl, alkenyl, alkadienyl, cycloalkenyl, cycloalkadienyl, aryl, aralkyl, alkylaryl, and alkynyl groups.

[0058] As used herein, the terms "substituted hydrocarbyl" and "substituted hydrocarbon" refer to a hydrocarbyl group substituted with one or more non-hydrocarbyl substituents. A non-limiting example of a non-hydrocarbyl substituent is a heteroatom. As used herein, "heteroatom" refers to an atom other than carbon or hydrogen. A heteroatom can be a non-carbon atom from Groups 13, 14, 15, 16, or 17 of the periodic table. Non-limiting examples of heteroatoms include halogens (F, Cl, Br, I), N, O, P, B, S, and Si. Substituted hydrocarbyl groups also include halohydrocarbyl groups and silicon-containing hydrocarbyl groups. As used herein, the term "halohydrocarbyl" group refers to a hydrocarbyl group substituted with one or more halogen atoms. As used herein, the term "silicon-containing hydrocarbyl group" refers to a hydrocarbyl group substituted with one or more silicon atoms. The silicon atom may or may not be in the carbon chain.

[0059] The internal electron donor, as shown above with respect to Formula I, includes R1-R4 groups that can vary. R1 and R4 can be the same or very similar. In some embodiments, for example, R1 and R4 are linear hydrocarbyl groups. For example, R1 and R4 can include C1-C8 alkyl groups, C2-C8 alkenyl groups, or mixtures thereof. For example, in some embodiments, R1 and R4 can both have the same carbon chain length or can include alkyl groups whose carbon chain length varies by about 3 carbon atoms or less, e.g., about 2 carbon atoms or less.

[0060] In some embodiments, R4 is a methyl group and R1 is a methyl group, an ethyl group, a propyl group, or a butyl group, or vice versa. In other alternative embodiments, both R1 and R4 are methyl groups, both R1 and R4 are ethyl groups, both R1 and R4 are propyl groups, or both R1 and R4 are butyl groups.

[0061] At least one of R2 or R3 is a larger or bulkier substituent than the R1 and R4 groups. The other of R2 or R3 is hydrogen or a methyl group. The larger or bulkier group at R2 or R3 can be, for example, a hydrocarbyl group having a branched or linear structure, or can include a cycloalkyl group having 5 to 15 carbon atoms. When either R2 or R3 has a branched or linear structure, the other can be a pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, or the like. For example, R2 or R3 can be a 3-pentyl group or a 2-pentyl group.

[0062] Further examples of internal electron donors are shown below: In each of the structures below, R1-R4 can be substituted with any of the groups in any of the combinations described above. [ka] wherein R6 to R15 may be the same or different, and each of R6 to R15 is selected from hydrogen, substituted hydrocarbyl groups having 1 to 20 carbon atoms, unsubstituted hydrocarbyl groups having 1 to 20 carbon atoms, alkoxyl groups having 1 to 20 carbon atoms, heteroatoms, and combinations thereof. [ka] In the formula, X1 and X2 may be oxygen, sulfur, or nitrogen-containing groups. In some embodiments, for example, X1 is oxygen and X2 is sulfur. R5 and R6 may each independently comprise an alkyl group or an aryl group. R5 and R6 may each, for example, comprise a C1-C8 alkyl group. [ka] wherein R16 and R17 are independently hydrogen or a C1-C20 hydrocarbyl group. In the above formula, X1 and X2 can be oxygen, sulfur, or nitrogen groups. Alternatively, one or both of X1 and X2 can be a hydrocarbyl group, such as an alkyl group containing 1 to 3 carbon atoms. X3 is an -OR group or an -NR1R2 group, where R, R1, or R2 is selected from a C1-C20 hydrocarbyl group optionally containing a heteroatom selected from halogen, phosphorus, sulfur, nitrogen, or oxygen. In some embodiments, X1 is a carbon atom and X3 is an ethyl group. [ka] In the formula, R5 can be an alkyl group or an aryl group, for example, R5 can be a C1 to C8 alkyl group. [ka] [ka] wherein R18 is hydrogen or a hydrocarbyl group containing from about 1 to about 8 carbon atoms. [ka] [ka] wherein R19, R20, and R21 may be the same or different and may be selected from hydrocarbyl groups having from about 1 to about 15 carbon atoms, optionally containing a heteroatom selected from halogen, phosphorus, sulfur, nitrogen, or oxygen. R20 and R21 may be the same or different and may be fused together to form one or more cyclic groups.

[0063] As described above, the procatalyst composition can include a combination of magnesium moieties, titanium moieties, and at least one internal electron donor. The procatalyst composition is produced by the aforementioned titanation procedure, which converts the procatalyst support and internal electron donor into a combination of magnesium and titanium moieties incorporating the internal electron donor. According to the present disclosure, a titanium extractant is contacted with the procatalyst during and / or after the titanation procedure to remove titanium species that are less active and not easily displaced by the internal electron donor. The titanium extractant removes titanium, which is primarily washed from the final product. The procatalyst support from which the procatalyst composition is formed can be a mixed magnesium / titanium precursor, a benzoate-containing magnesium chloride precursor, or a spherical precursor.

[0064] In one embodiment, the magnesium moiety is a magnesium halide, hi another embodiment, the magnesium halide is magnesium chloride or a magnesium chloride alcohol adduct.

[0065] In one embodiment, the titanium moiety is a titanium halide, such as titanium chloride, hi another embodiment, the titanium moiety is titanium tetrachloride.

[0066] In another embodiment, the procatalyst composition comprises a magnesium chloride precursor onto which titanium chloride is deposited and onto which an internal electron donor is incorporated.

[0067] The present disclosure is also directed to catalyst systems comprising the procatalyst compositions described above in combination with various other catalyst components. For example, in some embodiments, the catalyst composition includes a cocatalyst. As used herein, a "cocatalyst" is a substance capable of converting a procatalyst into an active polymerization catalyst. The cocatalyst may include aluminum, lithium, zinc, tin, cadmium, beryllium, magnesium chloride, alkyl, or aryl, and combinations thereof. In one embodiment, the cocatalyst is a hydrocarbyl aluminum cocatalyst represented by the formula RAl, where each R is an alkyl, cycloalkyl, aryl, or hydrido radical, at least one R is a hydrocarbyl radical, and two or three R radicals can be joined to form a cyclic radical to form a heterocyclic structure, where each R can be the same or different, and each R, which is a hydrocarbyl radical, has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. In further embodiments, each alkyl radical may be straight-chained or branched, and such hydrocarbyl radicals may be mixed radicals, i.e., the radicals may contain alkyl, aryl, and / or cycloalkyl groups. Non-limiting examples of suitable radicals are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, 2-methylpentyl, n-heptyl, n-octyl, isooctyl, 2-ethylhexyl, 5,5-dimethylhexyl, n-nonyl, n-decyl, isodecyl, n-undecyl, and n-dodecyl.

[0068] Non-limiting examples of suitable hydrocarbyl aluminum compounds are: triisobutylaluminum, tri-n-hexylaluminum, diisobutylaluminum chloride, di-n-hexylaluminum chloride, isobutylaluminum dichloride, n-hexylaluminum dichloride, diisobutylhexylaluminum, isobutyldihexylaluminum, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, tri-n-dodecylaluminum. In one embodiment, the cocatalyst is selected from triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diisobutylaluminum chloride, and di-n-hexylaluminum chloride.

[0069] In one embodiment, the cocatalyst has the formula R n AlX 3-n where n=1 or 2, R is alkyl, and X is halide. Non-limiting examples of suitable compounds are: diisobutylaluminum chloride, diethylaluminum chloride, ethylaluminum dichloride, methylaluminum dichloride, and dimethylaluminum chloride.

[0070] In one embodiment, the cocatalyst is triethylaluminum. The molar ratio of aluminum to titanium is from about 5:1 to about 500:1, or from about 10:1 to about 200:1, or from about 15:1 to about 150:1, or from about 20:1 to about 100:1. In another embodiment, the molar ratio of aluminum to titanium is about 45:1.

[0071] In one embodiment, the catalyst composition includes a selectivity control agent. As used herein, a "selectivity control agent" is a compound added independently of the procatalyst formulation and containing at least one functional group capable of donating a pair of electrons to a metal atom. Without being bound by theory, it is believed that the selectivity control agent improves the stereoselectivity of the catalyst (i.e., reduces the xylene soluble material in the formant polymer).

[0072] In one embodiment, the selectivity control agent donor may be selected from one or more of the following: alkoxysilanes, amines, ethers, carboxylates, ketones, amides, carbamates, phosphines, phosphates, phosphites, sulfonates, sulfones, and / or sulfoxides.

[0073] In one embodiment, the selectivity control agent donor is an alkoxysilane. Alkoxysilanes have the general formula: SiR m (OR') 4- m(I), where R is independently at each occurrence hydrogen or a hydrocarbyl or amino group optionally substituted with one or more substituents containing one or more Group 14, 15, 16, or 17 heteroatoms, said R containing up to 20 atoms excluding hydrogen and halogens, and R' is C 1~4 In one embodiment, R is an alkyl group, and m is 0, 1, 2, or 3. In one embodiment, R is 6~12 Aryl, alkyl or aralkyl, C 3~12 Cycloalkyl, C 3~12 Branched alkyl, or C 3~12 A cyclic or acyclic amino group, R' is C 1~4alkyl, and m is 1 or 2. Non-limiting examples of suitable silane compositions include dicyclopentyldimethoxysilane, di-tert-butyldimethoxysilane, methylcyclohexyldimethoxysilane, methylcyclohexyldiethoxysilane, ethylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, di-n-propyldimethoxysilane, diisobutyldimethoxysilane, diisobutyldiethoxysilane, isobutylisopropyldimethoxysilane, di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, diethylaminotriethoxysilane, cyclopentylpyrrolidinodimethoxysilane, bis(pyrrolidino)dimethoxysilane, bis(perhydroisoquinolino)dimethoxysilane, and dimethyldimethoxysilane. In one embodiment, the silane composition is dicyclopentyldimethoxysilane (DCPDMS), methylcyclohexyldimethoxysilane (MChDMS), or n-propyltrimethoxysilane (NPTMS), and any combination thereof.

[0074] In one embodiment, the selectivity control agent can be a mixture of at least two alkoxysilanes. In further embodiments, the mixture can be dicyclopentyldimethoxysilane and methylcyclohexyldimethoxysilane, dicyclopentyldimethoxysilane and tetraethoxysilane, or dicyclopentyldimethoxysilane and n-propyltriethoxysilane.

[0075] In one embodiment, the selectivity control agent is selected from one or more of the following: benzoates, succinates, and / or diol esters. In another embodiment, the selectivity control agent is a diether.

[0076] In one embodiment, the catalyst composition includes an activity limiting agent (ALA). As used herein, an "activity limiting agent" ("ALA") is a material that reduces catalyst activity at high temperatures (i.e., temperatures above about 85°C). ALA inhibits or otherwise prevents polymerization reactor failure and ensures the continuation of the polymerization process. Typically, the activity of a Ziegler-Natta catalyst increases as the reactor temperature increases. Ziegler-Natta catalysts also typically maintain high activity near the melting point temperature of the produced polymer. Heat generated by an exothermic polymerization reaction can cause polymer particles to form agglomerates, which can ultimately lead to an interruption in the continuation of the polymer production process. ALA reduces catalyst activity at high temperatures, thereby preventing reactor failure and reducing (or preventing) particle agglomeration, ensuring the continuation of the polymerization process.

[0077] The activity limiting agent can be a carboxylic acid ester, a diether, a poly(alkene glycol), a poly(alkene glycol) ester, a diol ester, or a combination thereof. The carboxylic acid ester can be an aliphatic or aromatic, mono- or polycarboxylic acid ester. Non-limiting examples of suitable monocarboxylic acid esters include ethyl and methyl benzoate, ethyl p-methoxybenzoate, methyl p-ethoxybenzoate, ethyl p-ethoxybenzoate, ethyl acrylate, methyl methacrylate, ethyl acetate, ethyl p-chlorobenzoate, hexyl p-aminobenzoate, isopropyl naphthenate, n-amyl toluate, ethyl cyclohexanoate, propyl pivalate, pentyl valerate, and octyl acetate.

[0078] Non-limiting examples of suitable polycarboxylic acid esters include dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di-tert-butyl phthalate, diisoamyl phthalate, di-tert-amyl phthalate, dineopentyl phthalate, di-2-ethylhexyl phthalate, di-2-ethyldecyl phthalate, diethyl terephthalate, dioctyl terephthalate, and bis[4-(vinyloxy)butyl]terephthalate. However, in some embodiments, the catalyst compositions and catalyst systems of the present disclosure are phthalate-free.

[0079] Aliphatic carboxylic acid esters are C4 to C 30 It can be an aliphatic acid ester, can be a mono- or poly(two or more) ester, can be linear or branched, can be saturated or unsaturated, and can be any combination thereof. 30 The aliphatic acid esters may also be substituted with substituents containing one or more Group 14, 15, or 16 heteroatoms. 30 Non-limiting examples of aliphatic acid esters include aliphatic C 4~30 Monocarboxylic acid C 1~20 Alkyl ester, aliphatic C 8~20 Monocarboxylic acid C 1~20 Alkyl ester, aliphatic C 4~20 C of monocarboxylic and dicarboxylic acids 1~4 Allyl mono- and diesters, aliphatic C 8~20 C of monocarboxylic and dicarboxylic acids 1~4 Alkyl esters, and C 2~100 (Poly)glycol or C 2~100 (Poly)glycol ether C 4~20 In a further embodiment, C4 to C6 30The fatty acid esters include laurate, myristate, palmitate, stearate, oleate, sebacate, (poly)(alkylene glycol) mono- or diacetate, (poly)(alkylene glycol) mono- or dimyristate, (poly)(alkylene glycol) mono- or dilaurate, (poly)(alkylene glycol) mono- or dioleate, glyceryl tri(acetate), C 2~40 In a further embodiment, the glyceryl tri-esters of fatty carboxylic acids may be C4 to C6 glyceryl tri-esters of fatty carboxylic acids, and mixtures thereof. 30 The aliphatic ester is isopropyl myristate or di-n-butyl sebacate.

[0080] In one embodiment, the activity limiting agent comprises a diether, which has the following structure (XV): [ka] where R1-R4 are, independently of one another, alkyl, aryl, or aralkyl groups having up to 20 carbon atoms, optionally containing heteroatoms of Group 14, 15, 16, or 17, and R1 and R2 may be hydrogen atoms. The dialkyl ether may be linear or branched and may contain one or more of the following groups: alkyl, alicyclic, aryl, alkylaryl, or arylalkyl radicals having 1 to 18 carbon atoms, and hydrogen. R1 and R2 may be linked to form a cyclic structure such as cyclopentadiene or fluorene.

[0081] In one embodiment, the activity limiting agent has the following structure (XVI): [ka] wherein R and R' can be the same or different, and R and / or R' comprises one or more of the following groups: hydrogen, linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl groups, optionally containing heteroatoms. One or more ring structures can be formed through one or both of the 2- and 3-carbon atoms.

[0082] In one embodiment, the activity limiting agent has the following structure (XVII): [ka] wherein n is an integer from 1 to 5. R1 and R2 may be the same or different and each may be selected from hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, allyl, phenyl, or halophenyl groups. R3, R4, R5, R6, R7, and R8 may be the same or different and each may be selected from hydrogen, halogen, and substituted or unsubstituted hydrocarbyl having 1 to 20 carbon atoms. The R1-R6 groups may optionally contain one or more heteroatoms replacing carbon, hydrogen, or both, where the heteroatoms are selected from nitrogen, oxygen, sulfur, silicon, phosphorus, and halogen. R7 and R8 may be the same or different and may be attached to any of the 2-, 3-, 4-, 5-, and 6-position carbon atoms of either phenyl ring.

[0083] In some embodiments, the catalyst system includes a mixed external electron donor, which includes at least two of the following components: (1) a first selectivity control agent, (2) a second selectivity control agent, and (3) an activity limiting agent.

[0084] In one embodiment, the selectivity control agent and / or activity limiting agent can be added separately to the reactor. In another embodiment, the selectivity control agent and activity limiting agent can be premixed together and then added to the reactor as a mixture. More than one selectivity control agent or activity limiting agent can be used in the mixture. In one embodiment, the mixture is dicyclopentyldimethoxysilane and isopropyl myristate, dicyclopentyldimethoxysilane and poly(ethylene glycol) laurate, dicyclopentyldimethoxysilane and isopropyl myristate and poly(ethylene glycol) dioleate, methylcyclohexyldimethoxysilane and isopropyl myristate, n-propyltrimethoxysilane and isopropyl myristate, dimethyldimethoxysilane and methylcyclohexyldimethoxysilane and isopropyl myristate, dicyclopentyldimethoxysilane and n-propyltriethoxysilane and isopropyl myristate, and dicyclopentyldimethoxysilane and tetraethoxysilane and isopropyl myristate, and combinations thereof.

[0085] In one embodiment, the catalyst composition comprises any of the aforementioned selectivity control agents in combination with any of the aforementioned activity limiting agents.

[0086] The present disclosure also relates to a process for producing olefin-based polymers using the catalyst composition described above. The use of a titanium extractant can produce a catalyst composition with increased stereoselectivity for producing polymers with lower xylene solubles content, for example. For example, the catalyst composition can be used to produce polyolefin polymers with reduced amorphous or atactic content.

[0087] In general, the catalyst composition of the present disclosure can be used in any suitable polymerization process, including gas-based or bulk processes. The process comprises contacting an olefin with the catalyst composition under polymerization conditions. The process further comprises forming an olefin-based polymer.

[0088] The catalyst composition may include a procatalyst composition and a cocatalyst. The catalyst composition may be any catalyst composition disclosed herein. The procatalyst composition may include a substituted phenylene compound as an internal electron donor. The cocatalyst may be any cocatalyst disclosed herein. The catalyst composition may optionally include a selectivity control agent and / or an activity limiting agent as previously disclosed.

[0089] The olefin-based polymer can be a propylene-based olefin, an ethylene-based olefin, and combinations thereof. In some embodiments, the olefin-based polymer is a propylene-based polymer.

[0090] One or more olefin monomers can be introduced into the polymerization reactor to react with the catalyst to form a polymer or a fluidized bed of polymer particles. Non-limiting examples of suitable olefin monomers include ethylene, propylene, C 4~20 α-olefins, such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, etc.; C 4~20 Diolefins, such as 1,3-butadiene, 1,3-pentadiene, norbornadiene, 5-ethylidene-2-norbornene (ENB), and dicyclopentadiene; C olefins, including styrene, o-, m-, and p-methylstyrene, divinylbenzene, vinylbiphenyl, and vinylnaphthalene; 8~40 Vinyl aromatic compounds; and halogen-substituted C 8~40 Vinyl aromatic compounds include, for example, chlorostyrene and fluorostyrene.

[0091] As used herein, "polymerization conditions" are temperature and pressure parameters in a polymerization reactor suitable for promoting polymerization between the catalyst composition and an olefin to form a desired polymer. The polymerization process can be a gas phase, slurry, or bulk polymerization process operating in one or more reactors.

[0092] Polymerization can occur via gas-phase polymerization. As used herein, "gas-phase polymerization" refers to the passage of an ascending fluidizing medium containing one or more monomers in the presence of a catalyst through a fluidized bed of polymer particles maintained in a fluidized state by a fluidizing medium or in an agitated gas medium. "Fluidization," "fluidized," or "fluidizing" refers to a gas-solid contact process in which a bed of fine polymer particles is lifted and agitated by an upward flow of gas. Fluidization occurs in a bed of particulate matter when the upward flow of fluid through the interstices of the particle bed achieves a pressure differential and an increase in frictional resistance that exceeds the weight of the particulate matter. Thus, a "fluidized bed" refers to a plurality of polymer particles suspended in a fluidized state by the flow of a fluidizing medium. The "fluidizing medium" refers to one or more olefin gases, optionally a carrier gas (e.g., H2 or N2), and optionally a liquid (e.g., a hydrocarbon) rising through a gas-phase reactor.

[0093] A typical gas-phase polymerization reactor (or gas-phase reactor) includes a vessel (i.e., reactor), a fluidized bed, a distribution plate, inlet and outlet piping, a compressor, a cycle gas cooler or heat exchanger, and a product discharge system. The vessel includes a reaction zone and a velocity reduction zone, each of which is located above the distribution plate. A bed is located in the reaction zone. In one embodiment, the fluidizing medium includes propylene gas and at least one other gas, such as an olefin, and / or a carrier gas, such as hydrogen or nitrogen.

[0094] The contacting can occur by feeding the catalyst composition into the polymerization reactor and introducing the olefin into the polymerization reactor. The cocatalyst can be mixed (premixed) with the procatalyst composition prior to introducing the procatalyst composition into the polymerization reactor. In another embodiment, the cocatalyst is added to the polymerization reactor independently of the procatalyst composition. The independent introduction of the cocatalyst into the polymerization reactor can occur simultaneously or substantially simultaneously with the feeding of the procatalyst composition.

[0095] In addition to the gas phase polymerization process, the catalyst composition of the present disclosure can also be used in a bulk phase process. In the bulk polymerization process, the catalyst composition is contacted with one or more liquid monomers, such as liquid propylene. Hydrogen can also be included in the reaction medium to control the molecular weight of the resulting polymer.

[0096] In one embodiment, the polymerization process may include a prepolymerization step. Prepolymerization involves contacting the procatalyst composition with a cocatalyst and a selectivity control agent and / or activity limiting agent, followed by addition of the procatalyst composition in an olefin polymerization step to result in a low conversion of about 0.5 to about 1000 grams of polymer per gram of solid procatalyst component. The prepolymerization step can be carried out as part of a continuous polymerization process or separately in a batch process. When carried out as part of a continuous process, the conversion of the prepolymerized catalyst component is preferably about 50 to about 500 grams of polymer per gram of solid catalyst component. The prepolymerized catalyst stream is then introduced into the main polymerization reaction zone and contacted with the remainder of the olefin monomer to be polymerized, optionally with additional amounts of one or more of the cocatalyst and selectivity control agent components. Prepolymerization combines the procatalyst composition with the cocatalyst and the selectivity control agent and / or activity limiting agent, and this combination is dispersed in the matrix of the formant polymer. Optionally, additional amounts of the cocatalyst, selectivity control agent and / or activity limiting agent may be added.

[0097] The polymerization process may include a preactivation step. Preactivation involves contacting the procatalyst composition with a cocatalyst and a selectivity control agent and / or activity limiting agent. The resulting preactivated catalyst stream is then introduced into a polymerization reaction zone and contacted with the olefin monomer to be polymerized, and optionally with one or more of the selectivity control agent components. Preactivation combines the procatalyst composition with the cocatalyst and the selectivity control agent and / or activity limiting agent. Optionally, an additional amount of the selectivity control agent and / or activity limiting agent may be added.

[0098] In one embodiment, polypropylene homopolymer is produced in a first reactor. The contents of the first reactor are then transferred to a second reactor where ethylene is introduced, resulting in the production of propylene-ethylene copolymer in the second reactor.

[0099] In one embodiment, the olefin is propylene. The process includes forming a propylene-based polymer having a melt flow rate (MFR) of from about 0.01 g / 10 min to about 800 g / 10 min, or from about 0.1 g / 10 min to about 200 g / 10 min, or from about 0.5 g / 10 min to about 150 g / 10 min. In a further embodiment, the propylene-based polymer is a polypropylene homopolymer.

[0100] As mentioned above, in one embodiment, the catalyst composition of the present disclosure can be used to reduce the xylene soluble content of polymers, particularly polypropylene polymers. For example, the resulting polypropylene polymer can have a xylene content of less than about 6 wt%, for example less than about 5 wt%, for example less than about 4 wt%, for example less than about 3 wt%, for example less than about 2 wt%, and generally more than about 0.1 wt%.

[0101] The catalyst compositions and catalyst systems of the present disclosure are also well suited for producing impact polymers with rubber-like or elastomeric properties. These polymers are typically made in a two-reactor system, where it is desirable for the catalyst to maintain a high activity level. In some embodiments, for example, polymerization is carried out in two reactors connected in series. To form an active propylene-based polymer, a propylene homopolymer or propylene copolymer can be formed in the first reactor. The active propylene-based polymer from the first polymerization reactor is then introduced into a second polymerization reactor and contacted with at least one second monomer in the second reactor under second polymerization conditions to form a propylene impact copolymer. In some embodiments, the process includes contacting the active propylene-based polymer with propylene and ethylene in the second polymerization reactor under polymerization conditions to form a discontinuous phase of a propylene / ethylene copolymer.

[0102] As noted above, the first phase polymer may comprise a polypropylene homopolymer. However, in an alternative embodiment, the first phase polymer may comprise a random copolymer of polypropylene.

[0103] The random copolymer may be, for example, a copolymer of propylene and an alpha-olefin such as ethylene. The polypropylene random copolymer forms the matrix polymer in the polypropylene composition and may contain less than about 12% by weight, for example, less than about 5% by weight, for example, less than about 4% by weight, and generally more than about 0.5% by weight, for example, more than about 1% by weight, for example, more than about 1.5% by weight, for example, more than about 2% by weight of the alpha-olefin. The first phase polymer generally has a xylene solubles content of less than about 12% by weight, for example, less than about 10% by weight, for example, less than about 8% by weight, for example, less than about 6% by weight, for example, less than about 4% by weight. The xylene solubles content is generally more than about 0.5% by weight, for example, more than about 3% by weight.

[0104] The first phase polymer may have a relatively broad molecular weight distribution, for example, a molecular weight distribution (Mw / Mn) greater than about 3.8, such as greater than about 4, for example greater than about 4.3, for example greater than about 4.5, for example greater than about 4.8, for example greater than about 5, for example greater than about 5.2, for example greater than about 5.5, for example greater than about 5.7, for example greater than about 6, and typically less than about 9, for example less than about 8.5, for example less than about 8. The weight average molecular weight (determined by GPC) of the first phase polymer is typically greater than about 100,000, for example greater than about 120,000.

[0105] In some embodiments, the polypropylene random copolymer or polypropylene homopolymer constituting the first phase polymer has a relatively high melt flow rate. For example, the first phase polymer may have a melt flow rate of greater than about 5 g / 10 min, e.g., greater than about 10 g / 10 min, e.g., greater than about 15 g / 10 min, e.g., greater than about 20 g / 10 min, e.g., greater than about 25 g / 10 min. The melt flow rate of the first phase polymer is generally less than about 1000 g / 10 min, e.g., less than about 500 g / 10 min.

[0106] The second phase polymer is a propylene and alpha-olefin copolymer. However, the second phase polymer has elastomeric or rubber-like properties. Therefore, the second phase polymer can dramatically improve the impact strength of the polymer.

[0107] The second phase polymer forming the dispersed phase in the polymer composition generally contains alpha-olefin or ethylene in an amount greater than about 10 wt%, for example greater than about 12 wt%, for example greater than about 14 wt%, and generally less than about 35 wt%, for example less than about 20 wt%, for example less than about 17 wt%. The second phase polymer may have a weight average molecular weight of at least about 130,000, for example at least about 140,000, for example at least about 150,000, and generally less than about 500,000.

[0108] The present disclosure may be better understood with reference to the following examples. General Procedure

[0109] Homopolymerization at 70°C. A 2-L stainless steel autoclave equipped with an overhead stirrer and thermostating jacket was purged with argon at 90°C for 1 hour, then cooled to 20°C and the argon was replaced with propylene gas. A cocatalyst solution was prepared by mixing 2.3 mmol of triethylaluminum and 0.078 mmol of dicyclopentyldimethoxysilane in 15 ml of hexane. 6 ml of the cocatalyst solution was added to charging tube A, and the remainder, along with approximately 3 mg of solid catalyst, was added to charging tube B. Hydrogen (57 mmol) was added to the reactor, and the contents of charging tube A were flushed into the reactor with 600 ml of propylene. The stirring was started, and the contents of charging tube B were flushed into the reactor with 450 ml of propylene. The reactor was heated to 70°C in 10 minutes, and polymerization was continued for 1 hour. At the end of the polymerization, the stirrer was turned off, and the unreacted propylene was vented while the reactor was cooled. The polymer was recovered and dried in a vacuum oven at 50°C before being weighed and analyzed.

[0110] When polymerizations were carried out in a 4 L autoclave, the same general procedure was followed except that 1400 ml and 600 ml of propylene were charged to charge tubes A and B. The reagent amounts for the 4 L polymerization were 2.0 L of propylene, 252 mmol of hydrogen, 3.4 mmol of triethylaluminum, 0.131 mmol of dicyclopentyldimethoxysilane, and 8.0 mg of catalyst.

[0111] Melt flow rate was measured for propylene-based polymers at 230°C using a 2.16 kg weight according to ASTM D1238-01 test method. Xylene solubles (XS) were measured using a Crystex automated instrument by Polymer Char. The Crystex was calibrated using polypropylene homopolymer samples analyzed for XS according to ASTM D5492-10 test method.

[0112] MgCl2 *The EtOH adduct was prepared as previously described in U.S. Patent No. 5,468,698. MgCl2 with an average particle size of 58 microns was used. * EtOH adduct and a 2.2 molar ratio of EtOH / Mg were used for catalysts E-12, E-13, C-6, and C-7. Examples C8, E14, and E115 were prepared using MgCl2 with a 3.2 molar ratio of EtOH / MgCl2. * Prepared using EtOH.

[0113] Example internal donor structures are shown in Table 1. [Table 1] Examples 1-3, Ethyl Benzoate as Secondary Donor

[0114] 4.0 g of MagTi support (U.S. Pat. Nos. 5,124,298 and 5,962,361) is added to a 100 ml Schlenk flask and slurried with 20 ml of monochlorobenzene (MCB). The slurry is transferred to the reactor under pure N2. Another 20 ml of MCB is added to the support flask and used to rinse any remaining support into the reactor, and the slurry is cooled to 12°C. Then, 40 ml (70 g) of TiCl4 cooled to 10°C is quickly added to the reactor. The slurry is heated to 25°C and stirred at this temperature for 5 minutes.

[0115] 2.37 (±0.03) mmol of either donor ID-1, ID-2, or ID-3 dissolved in 7 ml of o-chlorotoluene (OCT) is added to the reactor. The temperature is then increased to 100°C (40 min) and held there for 50 min. The stirring is stopped, and the slurry is allowed to settle while the reactor is maintained at 100°C. The supernatant is decanted, followed by the addition of 80 ml of a 50:50 volume mixture of TiCl4 and MCB preheated to 100°C. The reactor is heated to 115°C. While heating, 0.17 ml of ethyl benzoate (1.18 mmol) dissolved in 2 ml of OCT is added. The reaction mixture is held at 115°C for 25 min.

[0116] The agitation is stopped and the slurry is allowed to settle while the reactor is maintained at 115°C. The supernatant is decanted, followed by the addition of 80 ml of a 50:50 by volume mixture of TiCl4 and MCB preheated to 100°C. The reactor is reheated to 115°C and held at this temperature for 25 minutes. The agitation is stopped and the slurry is allowed to settle while the reactor is maintained at 115°C. The supernatant is decanted.

[0117] The reactor temperature is set to 25°C. 100 ml of heptane is then added, stirred for 10 minutes, then allowed to settle, and the wash is decanted. This is repeated four more times, with the reactor cooled, with the final two washes being performed with the reactor at 25°C. The wet solid is dried under vacuum at 40°C for 2 hours. 2.8-2.9 g of catalyst are collected. Catalyst composition data and polymerization results are shown in Table 2. Examples 4 and 5

[0118] 4.0 g of MagTi support is added to a 100 ml Schlenk flask and slurried with 20 ml of monochlorobenzene (MCB). The slurry is transferred to a reactor at room temperature under pure N2. Another 20 ml of MCB is added to the support flask and used to rinse any remaining support into the reactor. Then, 40 ml (70 g) of TiCl4 at room temperature or cooled to 10°C is quickly added to the reactor. The slurry is heated to 25°C and stirred at this temperature for 5 minutes.

[0119] Then, 2.35 (±0.02) mmol of either ID-1 or ID-2 donor dissolved in 7 ml of o-chlorotoluene (OCT) is added to the reactor. The temperature is then increased to 100°C (40 min) and held there for 50 min. The stirring is stopped and the slurry is allowed to settle while maintaining the reactor at 100°C. The supernatant is decanted, followed by the addition of 80 ml of a 50:50 volume mixture of TiCl4 and MCB. The reactor is heated to 115°C. While heating, 1.18 mmol of either ID-1 or ID-2 donor dissolved in 3.5 ml of OCT is added. The reaction mixture is held at 115°C for 25 min.

[0120] The agitation is stopped and the slurry is allowed to settle while the reactor is maintained at 115°C. The supernatant is decanted, followed by the addition of 80 ml of a 50:50 volume mixture of TiCl4 and MCB. The reactor is reheated to 115°C and held at this temperature for 25 minutes. The agitation is stopped and the slurry is allowed to settle while the reactor is maintained at 115°C. The supernatant is decanted.

[0121] The reactor temperature is set to 25°C. 100 ml of heptane is then added, stirred for 10 minutes, then allowed to settle, and the wash is decanted. This is repeated four more times, with the reactor cooled, with the final two washes being performed with the reactor at 25°C. The wet solid is dried under vacuum at 40°C for 2 hours. 2.9 g to 3.0 g of catalyst is collected. Catalyst composition data and polymerization results are shown in Table 3. Example 6

[0122] 4.0 g of MagTi support is added to a 100 ml Schlenk flask and slurried with 20 ml of monochlorobenzene (MCB). The slurry is transferred to a reactor at room temperature under pure N2. Another 20 ml of MCB is added to the support flask and used to rinse any remaining support into the reactor. Then, 40 ml (70 g) of TiCl4 at room temperature or cooled to 10°C is quickly added to the reactor. The slurry is heated to 25°C and stirred at this temperature for 5 minutes.

[0123] Then, 3.55 mmol of ID-3 donor dissolved in 5.1 ml of o-chlorotoluene (OCT) is added to the reactor. The temperature is then increased to 100°C (40 minutes) and held there for 50 minutes. The stirring is stopped, and the slurry is allowed to settle while the reactor is maintained at 100°C. The supernatant is decanted, followed by the addition of 80 ml of a 50:50 volume mixture of TiCl4 and MCB. The reactor is heated to 115°C. While heating, 1.60 mmol of A0 donor dissolved in 2.3 ml of OCT is added. The reaction mixture is held at 115°C for 25 minutes.

[0124] The agitation is stopped and the slurry is allowed to settle while the reactor is maintained at 115°C. The supernatant is decanted, followed by the addition of 80 ml of a 50:50 volume mixture of TiCl4 and MCB. The reactor is reheated to 115°C and held at this temperature for 25 minutes. The agitation is stopped and the slurry is allowed to settle while the reactor is maintained at 115°C. The supernatant is decanted.

[0125] The reactor temperature is set to 25°C. 100 ml of heptane is then added, stirred for 10 minutes, then allowed to settle, and the wash is decanted. This is repeated four more times, with the reactor cooled, with the final two washes being performed with the reactor at 25°C. The wet solid is dried under vacuum at 40°C for 2 hours. 2.9 g to 3.0 g of catalyst is collected. Catalyst composition data and polymerization results are shown in Table 3. Examples 7 and 8

[0126] The procedures of Examples 4 and 5 were followed, except that no donor was added to the second titanation. Catalyst composition data and polymerization results are shown in Table 3. [Table 2] [Table 3]

[0127] The above data show that omitting the donor in the second titanation results in a catalyst with higher Ti, lower activity, and higher XS. Surprisingly, the amount of donor incorporated into the catalyst remained nearly the same as when a full loading of donor was used.

[0128] Without being bound by any particular hypothesis, the function of the donor in the second titanation appears to be to help extract titanium species that are less active and have poorer steroregulating ability than species remaining after the second titanation using a higher amount of donor. Examples 9 to 16

[0129] In the following examples, the procedure used in Examples 1-3 was followed, except that the donors and amounts used in the first and second titanations were as listed in Table 4. The compositions and polymerization results are also shown in Table 4. [Table 4] Examples 17 to 19

[0130] 20g MgCl2 * The EtOH precursor and 73 ml of heptane were added to a 1 L jacketed glass reactor equipped with an overhead stirrer, and the mixture was cooled to -20 °C. 350 g of TiCl4 pre-cooled to -20 °C was added, and stirring was continued for 1 hour. The reactor temperature was increased to 20 °C at a rate of 0.33 °C / min. A solution of 1.5 g of ethyl benzoate in 5 ml of heptane was added via cannula. After the addition was complete, the reactor temperature was increased to 85 °C at a rate of 0.54 °C / min. During the temperature increase, a solution of 1.8 g of internal donor in 30 ml of toluene was metered in at a rate of 0.4 mL / min. After reaching 85 °C, stirring was continued for 1 hour, after which the catalyst solid was allowed to settle, and the supernatant was decanted. 70 g of preheated TiCl4 and 140 g of toluene were added, followed by 1.2 g of internal donor in 10 ml of toluene, and the mixture was stirred at 105 °C for 1 hour, after which the settling and decanting step was repeated. The TiCl4 / toluene treatment was repeated at 120 °C for 1 hour. After settling and decanting, the reactor was cooled to 65 °C. The catalyst solid was washed five times with 200 ml of heptane per wash at 65 °C. The catalyst was then dried under vacuum at 40 °C for 4 hours. The catalyst composition, internal donor type, and bulk polymerization test data are listed in Table 5. Example 20

[0131] 20g MgCl2 *The EtOH precursor and 73 ml of heptane were added to a 1 L jacketed glass reactor equipped with an overhead stirrer, and the mixture was cooled to -20 °C. 350 g of TiCl4 pre-cooled to -20 °C was added, and stirring was continued for 1 h. The reactor temperature was increased to 20 °C at a rate of 0.33 °C / min and stirred for 15 min. The reactor temperature was increased to 85 °C at a rate of 0.54 °C / min, and a solution of 2.0 g of ID-1 in 30 ml of toluene was metered in at a rate of 0.4 mL / min during heating. After reaching 85 °C, stirring was continued for 1 h, after which the catalyst solid was allowed to settle and the supernatant was decanted. 70 g of preheated TiCl4 and 140 g of toluene were added, followed by 1.5 g of ethyl benzoate in 7 ml of heptane, and the mixture was stirred at 105 °C for 1 h, after which the settling and decanting steps were repeated. The TiCl / toluene treatment was repeated for 1 hour at 120°C. After settling and decanting, the reactor was cooled to 65°C. The catalyst solid was washed five times with 200 ml of heptane per wash at 65°C. The catalyst was then dried under vacuum at 40°C for 4 hours. The catalyst composition and bulk polymerization test data are listed in Table 5. Example 21

[0132] The E-17 procedure was followed except that the ethyl benzoate addition step was omitted. The catalyst composition and bulk polymerization test data are listed in Table 5. Example 22

[0133] 20g MgCl2 *The EtOH precursor and 73 ml of heptane were added to a 1 L jacketed glass reactor equipped with an overhead stirrer, and the mixture was cooled to -20 °C. 350 g of TiCl4 pre-cooled to -20 °C was added, and stirring was continued for 1 hour. The reactor temperature was raised to 20 °C at a rate of 0.33 °C / min. A solution of 2.4 g of ethyl benzoate in 10 ml of heptane was added via cannula and stirred for 15 minutes. The reactor temperature was raised to 85 °C at a rate of 0.54 °C / min, and stirring was continued for 1 hour, after which the catalyst solid was allowed to settle and the supernatant was decanted. 70 g of preheated TiCl4 and 140 g of toluene were added, followed by 0.9 g of ethyl benzoate in 5 ml of heptane, and the mixture was stirred at 105 °C for 1 hour, after which the settling and decanting steps were repeated. The TiCl4 / toluene treatment was repeated for 1 hour at 120 °C. After settling and decanting, the reactor was cooled to 65° C. The catalyst solid was washed five times with 200 ml of heptane per wash at 65° C. The catalyst was then dried under vacuum at 40° C. for 4 hours. The catalyst composition and bulk polymerization test data are listed in Table 5. [Table 5] The polymerization was carried out in a 4 L autoclave.

[0134] Examples E-23 to E-25 use MgCl2 as a carrier. * 3.2 shows the preparation and behavior of catalysts prepared using EtOH and 1,8-naphthalenedibenzoate as the internal donor. [Table 6] Example 23

[0135] Without ethyl benzoate, MgCl2 * Experiments were carried out using EtOH support and 1,8-naphthalene dibenzoate. The catalyst exhibits moderate activity (48.2 kg / g) and very high XS levels (9.29%).

[0136] In reactor (1), MgCl *EtOH (16.3 g) and heptane (68 g) were charged and cooled to -25°C. Reactor (2) was charged with TiCl4 (207 g) and cooled to -23°C. The support slurry from reactor (1) was transferred to reactor (2) while maintaining an internal temperature of -20°C and an agitation speed of 400 rpm, and the reaction mixture was held for 1 hour. The reactor temperature was increased from -20°C to 20°C over 2 hours and from 20°C to 85°C over 3 hours, held at 85°C for 1 hour, and filtered. The solid was washed twice with toluene (130 ml), and then additional toluene (130 ml) was added. The reactor was heated to 105°C. 1,8-naphthalene dibenzoate (1.0 g) was added at 80°C. The reaction mixture was stirred at 105°C for 1 hour. After filtration, the solid portion was treated four times with 10% (w) TiCl4 / toluene at 105 and 110°C. Example 24

[0137] Example E-23 was repeated, except that 2.0 g of ethyl benzoate was added at 20° C. after the completion of TiCl addition. This example shows the effect of ethyl benzoate on catalyst performance. The catalyst activity increased dramatically to 74.6 kg / g, and the XS level decreased to 3.25%. Example 25

[0138] TiCl4 to MgCl2 * Example E-24 was repeated, except that EtOH was added. This example demonstrates a different titanation method in the presence of ethyl benzoate. The catalyst exhibits high activity (47.8 kg / g) and good XS level (3.68%).

[0139] To understand the effect on catalytic performance, FTIR studies of the catalysts were carried out.

[0140] The IR spectra of catalysts prepared with 1,8-naphthalenedibenzoate, with ethyl benzoate, and without ethyl benzoate are shown in Figures 1 and 2. The FTIR spectra are different. Both catalysts have slightly different coordination (1702 cm -1 and 1698 cm -1The catalyst prepared with ethyl benzoate from Example E-23 contains a 1,8-naphthalene dibenzoate complex with MgCl (1669 cm corresponding to the -C=O band at 1669 cm). -1 region) and complex with TiCl4 (1640 cm -1 The bands in the region are shown.

[0141] The FTIR data supports the difference in catalyst behavior in the polymerization process.

[0142] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art without departing from the spirit and scope of the present invention, which is particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged in whole or in part. Furthermore, those skilled in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the invention as further set forth in such appended claims. The present invention includes the following aspects. [1] 1. A process for producing a Ziegler-Natta procatalyst composition, comprising: subjecting a magnesium-containing procatalyst to at least a first titanation step and a second titanation step; incorporating an internal electron donor into said procatalyst; contacting said procatalyst with a titanium extractant during or after said titanation step, wherein said titanium extractant removes titanium on said procatalyst. [2] 2. The process of claim 1, wherein the titanium extractant comprises an ester, a ketone, a carbonate, or a mixture thereof. [3] 2. The process of claim 1, wherein the titanium extractant comprises a monoester. [4] 2. The process of claim 1, wherein the titanium extractant comprises an alkyl benzoate, such as ethyl benzoate. [5] 5. The process of any one of 1 to 4, wherein the internal electron donor comprises an aryl diester. [6] The internal electron donor has the following formula: [ka] and naphthyl dibenzoates having the formula wherein each R is independently hydrogen, halogen, alkyl having 1 to about 8 carbon atoms, phenyl, arylalkyl having 7 to about 18 carbon atoms, or alkylaryl having 7 to about 18 carbon atoms. In another embodiment, each R is independently hydrogen, alkyl having 1 to about 6 carbon atoms, phenyl, arylalkyl having 7 to about 12 carbon atoms, or alkylaryl having 7 to about 12 carbon atoms. [7] 7. The process of any one of 1 to 6, wherein the procatalyst is contacted with the titanium extractant during the first titanation step. [8] 7. The process of any one of 1 to 6, wherein the procatalyst is contacted with the titanium extractant during the second titanation step. [9] 7. The process of any one of claims 1 to 6, wherein during the first titanation step, the procatalyst is contacted with the internal electron donor in the absence of the titanium extractant, and during the second titanation step, the procatalyst is contacted with the titanium extractant in the absence of the internal electron donor.

[10] 7. The process of any one of claims 1 to 6, wherein during the first titanation step, the procatalyst is contacted with the internal electron donor and the titanium extractant, and during the second titanation step, the procatalyst is contacted with the internal electron donor, the titanium extractant, or both the internal electron donor and the titanium extractant.

[11] 11. The process of any one of 1 to 10, wherein the procatalyst comprises a spray-crystallized magnesium halide compound.

[12] 12. The process of claim 11, wherein the spray-crystallized magnesium halide compound comprises ethanol and magnesium chloride in a weight ratio of about 1.5:1 to about 3.1:1.

[13] The internal electron donor is

change

[14] R 2 and R 3 14. The process of claim 13, wherein at least one of comprises a hydrocarbyl group having a branched or linear structure or comprising a cycloalkyl group having from 5 to 15 carbon atoms.

[15] The magnesium moiety has the formula: Mg(OR)nX 2-n Lm wherein R comprises an alkyl group or an aryl group containing a halogen atom, n is 0 to 2, L comprises an ether and / or alcohol coordinated ligand group, and m is the number of coordinated ligands and is 0 to 10; The titanium moiety has the following formula: Ti(OR) g X 4-g wherein each R is independently selected from the group consisting of C 1 ~C 4 15. The process of any one of claims 1 to 14, wherein X is an alkyl group, X is bromine, chlorine, or iodine, and g is 0, 1, 2, or 3.

[16] 16. A catalyst composition comprising the procatalyst composition of any one of 1 to 15 in combination with a cocatalyst and optionally a selectivity control agent.

[17] 17. The catalyst composition of claim 16, wherein the co-catalyst comprises triethylaluminum.

[18] 17. The catalyst composition of claim 16, wherein the selectivity control agent is present and comprises an alkoxysilane.

[19] The selectivity control agent may be dicyclopentyldimethoxysilane, di-tert-butyldimethoxysilane, methylcyclohexyldimethoxysilane, methylcyclohexyldiethoxysilane, ethylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, di-n-propyldimethoxysilane, diisobutyldimethoxysilane, diisobutyldiethoxysilane, isobutylisopropyldimethoxysilane, di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, 17. The catalyst composition of claim 16, comprising diethylaminotriethoxysilane, cyclopentylpyrrolidinodimethoxysilane, bis(pyrrolidino)dimethoxysilane, bis(perhydroisoquinolino)dimethoxysilane, dimethyldimethoxysilane, or a mixture thereof.

[20] 20. The catalyst composition according to any one of 16 to 19, further comprising an activity limiting agent.

[21] 21. The catalyst composition of claim 20, wherein the activity limiting agent comprises a carboxylic acid ester.

[22] The procatalyst has the formula: Mg(OR)nX2-nLm wherein R comprises an alkyl or aryl group containing a halogen atom, n is 0 to 2, L comprises an ether and / or alcohol coordinated ligand group, and m is the number of coordinated ligands and is 0 to 10; and the following formula: Ti(OR)gX4-g wherein each R is independently a C1-C4 alkyl group; X is bromine, chlorine, or iodine; and g is 0, 1, 2, or 3.

[23] 23. A process for producing a polyolefin polymer, comprising polymerizing propylene monomer and optionally one or more comonomers in the presence of the catalyst composition of any one of claims 16 to 22.

[24] 24. The process of claim 23, wherein the process produces a polypropylene polymer having a xylene solubles content of about 0.5% to about 6% by weight.

Claims

1. 1. A process for producing a Ziegler-Natta procatalyst composition, comprising: subjecting a magnesium-containing procatalyst to at least a first titanation step and a second titanation step; incorporating an internal electron donor into said procatalyst during said first titanation step; contacting said procatalyst with a titanium extractant during or after said second titanation step, wherein said titanium extractant removes titanium on said procatalyst, said titanium extractant comprising an alkyl benzoate, and wherein at least one of said internal electron donor and said titanium extractant contacts said procatalyst during the first titanation step and the second titanation step.

2. 10. The process of claim 1, wherein the alkyl benzoate comprises ethyl benzoate.

3. The process of any one of claims 1 to 2, wherein the internal electron donor comprises an aryl diester.

4. The internal electron donor has the following formula: 【Chemistry 1】 and naphthyl dibenzoates having the formula wherein each R is independently hydrogen, halogen, alkyl having 1 to about 8 carbon atoms, phenyl, arylalkyl having 7 to about 18 carbon atoms, or alkylaryl having 7 to about 18 carbon atoms. In another embodiment, each R is independently hydrogen, alkyl having 1 to about 6 carbon atoms, phenyl, arylalkyl having 7 to about 12 carbon atoms, or alkylaryl having 7 to about 12 carbon atoms.

5. The process of any one of claims 1 to 4, wherein the procatalyst is contacted with the titanium extractant during the first titanation step.

6. The process of any one of claims 1 to 4, wherein the procatalyst is contacted with the titanium extractant during the second titanation step.

7. 5. The process of any one of claims 1 to 4, wherein during the first titanation step, the procatalyst is contacted with the internal electron donor in the absence of the titanium extractant, and during the second titanation step, the procatalyst is contacted with the titanium extractant in the absence of the internal electron donor.

8. 5. The process of any one of claims 1 to 4, wherein during the first titanation step, the procatalyst is contacted with the internal electron donor and the titanium extractant, and during the second titanation step, the procatalyst is contacted with the titanium extractant or both the internal electron donor and the titanium extractant.

9. The process of any one of claims 1 to 8, wherein the procatalyst comprises a spray-crystallized magnesium halide compound.

10. 10. The process of claim 9, wherein the spray-crystallized magnesium halide compound comprises ethanol and magnesium chloride in a weight ratio of about 1.5:1 to about 3.1:

1.

11. The internal electron donor is 【Chemistry 2】 Including, In the formula, R １ and R ４ are each hydrogen or a hydrocarbyl group having 1 to 20 carbon atoms; R ２ and R ３ At least one of R is hydrogen; ２ and R ３ at least one of E contains a substituted or unsubstituted hydrocarbyl group having 1 to 20 carbon atoms; １ and E ２ are the same or different and are selected from the group consisting of alkyl having 1 to 20 carbon atoms, substituted alkyl having 1 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, substituted aryl having 6 to 20 carbon atoms, or an inert functional group having 1 to 20 carbon atoms, optionally containing heteroatoms; X １ and X ２ are each O, S, an alkyl group, or NR ５ and R ５ The process of any one of claims 1 or 5 to 10, wherein is a hydrocarbyl group having 1 to 20 carbon atoms or is hydrogen.

12. R ２ and R ３ The process of claim 11, wherein at least one of comprises a hydrocarbyl group having a branched or linear structure or comprising a cycloalkyl group having from 5 to 15 carbon atoms.

13. The magnesium moiety has the formula: Mg(OR) ｎ X ２－ｎ Lm wherein R comprises an alkyl or aryl group containing a halogen atom, n is 0 to 2, L comprises an ether and / or alcohol coordinated ligand group, m is the number of coordinated ligands and is 0 to 10, and X is bromine, chlorine, or iodine; The titanium moiety has the formula: Ti(OR) ｇ X ４－ｇ wherein each R is independently selected from the group consisting of C １ ~C ４ 13. The process of any one of claims 1 to 12, wherein X is an alkyl group, X is bromine, chlorine, or iodine, and g is 0, 1, 2, or 3.

14. A catalyst composition comprising the procatalyst composition of any one of claims 1 to 13 in combination with a cocatalyst and, optionally, a selectivity control agent.

15. 15. The catalyst composition of claim 14, wherein the cocatalyst comprises triethylaluminum.

16. 15. The catalyst composition of claim 14, wherein the selectivity control agent is present and comprises an alkoxysilane.

17. 15. The catalyst composition of claim 14, wherein the selectivity control agent comprises dicyclopentyldimethoxysilane, di-tert-butyldimethoxysilane, methylcyclohexyldimethoxysilane, methylcyclohexyldiethoxysilane, ethylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, di-n-propyldimethoxysilane, diisobutyldimethoxysilane, diisobutyldiethoxysilane, isobutylisopropyldimethoxysilane, di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, diethylaminotriethoxysilane, cyclopentylpyrrolidinodimethoxysilane, bis(pyrrolidino)dimethoxysilane, bis(perhydroisoquinolino)dimethoxysilane, dimethyldimethoxysilane, or a mixture thereof.

18. The catalyst composition of any one of claims 14 to 17, wherein the catalyst composition further comprises an activity limiting agent.

19. 20. The catalyst composition of claim 18, wherein the activity limiting agent comprises a carboxylic acid ester.

20. The procatalyst has the formula: Mg(OR) ｎ X ２－ｎ L ｍ wherein R comprises an alkyl or aryl group containing a halogen atom, n is 0-2, L comprises an ether and / or alcohol coordinated ligand group, m is the number of coordinated ligands and is 0-10, and X is bromine, chlorine, or iodine; and the following formula: Ti(OR) ｇ X ４－ｇ wherein each R is independently a C1-C4 alkyl group; X is bromine, chlorine, or iodine; and g is 0, 1, 2, or 3.

21. 21. A process for producing a polyolefin polymer, comprising polymerizing propylene monomer and optionally one or more comonomers in the presence of the catalyst composition of any one of claims 14 to 20.

22. 22. The process of claim 21, wherein the process produces a polypropylene polymer having a xylene solubles content of from about 0.5% to about 6% by weight.

23. 1. A process for producing a Ziegler-Natta procatalyst composition, comprising: subjecting a magnesium-containing procatalyst to at least a first titanation step and a second titanation step; incorporating an internal electron donor comprising an aryl diester into said procatalyst during a first titanation step; contacting the procatalyst with a titanium extractant during or after a second titanation step, wherein the titanium extractant removes titanium on the procatalyst, the titanium extractant comprising a monoester, a ketone, a carbonate, or a mixture thereof; the monoesters include methyl benzoate, ethyl benzoate, phenyl benzoate, ethyl anisate, benzyl acetate, ethyl acetate, octyl acetate, ethyl propionate, ethyl butyrate, methyl butyrate, methyl laurate, methyl valerate, pentyl valerate, ethyl hexanoate, and mixtures thereof; the ketone comprises methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, acetone, diethyl ketone, ethyl phenyl ketone, butyl phenyl ketone, 3-hexanone, and mixtures thereof; The process wherein the carbonate comprises dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, and mixtures thereof.

Images