Carbonate Compounds as Activity Limiting Agents in Ziegler-Natta Catalyst Compositions for Olefin Polymerization

Abstract

Disclosed is a Ziegler-Natta catalyst composition comprising one or more Ziegler-Natta procatalyst compositions containing magnesium, titanium, a halogen, and one or more internal electron donors; one or more aluminum-containing cocatalysts; optionally one or more stereoselectivity control agents (SCAs); and one or more activity limiting agents (ALAs) containing one or more alkyl-, cycloalkyl-, or aryl carbonates and derivatives. Such Ziegler-Natta catalyst compositions exhibit self-limiting catalytic activity in olefin polymerization, particularly propylene polymerization.

Description

[Technical Field]

[0001] This invention relates to Ziegler-Natta catalyst compositions comprising one or more Ziegler-Natta procatalyst compositions containing magnesium, titanium, a halogen, and one or more internal electron donors; one or more aluminum-containing cocatalysts; optionally one or more external stereoselectivity control agents (SCAs); and one or more activity limiting agents (ALAs) containing one or more alkyl-, cycloalkyl-, or aryl carbonates and derivatives. The invention further relates to methods for making the novel polymerization catalyst compositions and to polymerization processes for producing polyolefins, particularly polypropylene, using the novel catalyst compositions. [Background technology]

[0002]

[0002] Ziegler-Natta catalyst compositions for olefin polymerization are well known in the art. Generally, these catalyst systems are composed of a solid Ziegler-Natta procatalyst component and a cocatalyst component, usually an organoaluminum compound. To increase the activity and stereospecificity of the catalyst system for the polymerization of α-olefins, an electron donor compound can be incorporated into the Ziegler-Natta procatalyst component during catalyst preparation, which is used as an internal electron donor, and / or can be charged to the polymerization reactor during the polymerization process, which is used as an external stereoselectivity control agent (SCA) together with the solid Ziegler-Natta procatalyst component and the cocatalyst component.

[0003]

[0003] Common internal electron donor compounds incorporated into solid Ziegler-Natta procatalyst components during the preparation of such components are well known in the art and include organic acid esters, ethers, ketones, amines, alcohols, heterocyclic organic compounds, phenols, phosphines, silanes, and the like. It is well known in the art that the polymerization activity, as well as the stereoregularity, molecular weight, and molecular weight distribution of the resulting polymer, depend on the molecular structure of the internal electron donor used. Therefore, there is an attempt and desire to develop various internal electron donors to improve the polymerization process and the properties of the resulting polymer.Examples of such internal electron donor compounds and their use as components of catalyst systems are described in U.S. Pat. Nos. 4,107,414; 4,186,107; 4,226,963; 4,347,160; 4,382,019; 4,435,550; 4,465,782; 4,522,930; 4,530,912; 4,532,313; 4,560,671; 4,657,882; 5,208,302; 5,900; No. 2,765; No. 5,948,872; No. 6,048,818; No. 6,121,483; No. 6,281,301 ; Same No. 6,294,497; Same No. 6,313,238; Same No. 6,395,670, Same No. 6,436,864, Same No. 6,60 No. 5,562; No. 6,716,939; No. 6,770,586; No. 6,818,583; No. 6,825,309; Same No. 7,022,640; Same No. 7,049,377; Same No. 7,202,314; Same No. 7,208,435; Same No. 7,223 , No. 712; No. 7,351,778; No. 7,371,802; No. 7,491,781; No. 7,544,748; Same No. 7,674,741; Same No. 7,674,943; Same No. 7,888,437; Same No. 7,888,438; Same No. 7,935 , No. 766; No. 7,964,678; No. 8,003,558; No. 8,003,559; No. 8,088,872; Same No. 8,211,819; Same No. 8,222,357; Same No. 8,227,370; Same No. 8,236,908; Same No. 8,247 ,341; 8,263,520; 8,263,692; 8,288,304; 8,288,585; 8,288,606; 8,318,626; 8,383,540; 8,536,290, 8,569,195; 8,575,283; 8,604,146; 8,633,126; 8,692,927; 8,664,142; 8,680,222; 8,716,514 and 8,742,040.

[0004] Acceptable external stereoselectivity control agents (SCAs) include organic compounds containing O, Si, N, S, and / or P. Such compounds include organic acids, organic acid esters, organic acid anhydrides, ethers, ketones, alcohols, aldehydes, silanes, amides, amines, amine oxides, thiols, and various phosphites and amides. Preferred external SCAs are organosilicon compounds with silicon as the central atom, containing Si—O—C and / or Si—N—C bonds. Such compounds are disclosed in U.S. Patent Nos. 4,472,524; 4,473,660; 4,560,671; 4,581,342; 4,657,882; 5,106,807; 5,407,883; 5,684,173; 6,228,961; Nos. 6,362,124; 6,552,136; 6,689,849; 7,009,015; 7,244,794; 7,276,463; 7,619,049; 7,790,819; 8,247,504; 8,648,001; and 8,614,162.

[0005]

[0005] In response to the temperature dependence of catalyst activity, activity limiting agents (ALAs) have recently been developed. The use of certain carboxylic acid esters, diethers, and derivatives in conjunction with Ziegler-Natta procatalyst compositions and external SCAs results in catalyst compositions that are essentially self-limiting with respect to temperature. Such catalyst compositions have much lower activity at elevated polymerization temperatures, especially temperatures above 100°C, compared to catalyst activity under normal polymerization conditions, typically at reaction temperatures below 80°C. Advantages of using such catalyst compositions include reduced reactor fouling or sheeting and improved polymerization process control. Examples of such ester and diether compounds and their use as ALA are described in U.S. Pat. Nos. 7,491,670; 7,678,868; 7,781,363; 8,536,290; 9,796,796; and 10,926,234, which are incorporated by reference in their entireties. Summary of the Invention [Problem to be solved by the invention]

[0006]

[0006] Despite the advances made by the above disclosures, there remains a need and desire to develop catalyst compositions which not only have reduced polymerization activity at elevated reaction temperatures, but also produce polyolefins with well-controlled physical properties, especially when the reaction temperature exceeds the normal range. [Means for solving the problem]

[0007]

[0007] The present invention is a Ziegler-Natta catalyst composition comprising one or more Ziegler-Natta procatalyst compositions comprising magnesium, titanium, a halogen, one or more internal electron donors; one or more aluminum-containing cocatalysts; optionally one or more stereoselectivity control agents (SCAs); and one or more activity limiting agents (ALAs) comprising one or more alkyl-, cycloalkyl-, or aryl carbonates and derivatives. In one embodiment of the present invention, the Ziegler-Natta catalyst composition meets the above-mentioned requirements by exhibiting self-limiting catalytic activity in the polymerization of olefins, particularly propylene.

[0008] The present invention relates to a catalyst system for the polymerization or copolymerization of α-olefins, comprising a solid Ziegler-Natta procatalyst component, a cocatalyst component, optionally an external SCA component, and a carbonate compound as the ALA component. Suitable ALA carbonate compounds in the catalyst composition of the present invention are represented by the following formula I: R 1 OC(=O)OR 2 [Formula I] (R in the formula 1 and R 2 may be the same or different and are independently selected from hydrogen, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 4 to 20 carbon atoms, or a hetero atom containing a hydrocarbon group of 1 to 20 carbon atoms; R 1 and R 2 may be linked to form one or more saturated or unsaturated monocyclic or polycyclic rings). DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0009] The present invention provides a catalyst composition for the polymerization and copolymerization of olefins, particularly propylene or a mixture of propylene and a comonomer, said catalyst composition comprising one or more Ziegler-Natta procatalyst compositions containing magnesium, titanium, a halogen, and one or more internal electron donors; one or more aluminum-containing cocatalysts; optionally one or more external stereoselectivity control agents (SCAs); and one or more activity limiting agents (ALAs) containing one or more alkyl-, cycloalkyl- or aryl carbonates and derivatives, said ALA compounds and amounts being charged into a polymerization reactor such that the polymerization activity of the catalyst composition at temperatures above 85°C, preferably above 100°C, is lower than the polymerization activity of the catalyst composition at said temperatures in the absence of ALA.

[0010] In accordance with some aspects of the present invention, suitable carbonate compounds in the catalyst compositions of the present invention are represented by Formula I: R 1 OC(=O)OR 2 [Formula I] (R in the formula 1 and R 2 may be the same or different and are independently selected from hydrogen, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 4 to 20 carbon atoms, or a heteroatom-containing hydrocarbon group having 1 to 20 carbon atoms; R 1 and R 2 may be linked to form one or more saturated or unsaturated monocyclic or polycyclic rings).

[0011]

[0011] Preferred examples of suitable carbonate compounds of formula I include, but are not limited to: dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, di-n-butyl carbonate, propylene carbonate, 2-ethoxyethyl ethyl carbonate, didodecyl carbonate, diphenyl carbonate, t-butylphenyl carbonate, bis(4-chlorophenyl) carbonate, 3,4-dichlorobenzylhexyl carbonate, ethylene glycol bis-(methyl carbonate), diethyl 2,5-dioxahexanedioate.

[0012]

[0012] Typical acceptable Ziegler-Natta catalyst compositions that can be used in accordance with the present invention include (a) a solid Ziegler-Natta procatalyst component, (b) a cocatalyst component, optionally (c) one or more stereoselectivity control agents (SCAs), and (d) one or more carbonate compounds of formula I used as activity limiting agents (ALAs).

[0013]

[0013] A preferred solid Ziegler-Natta procatalyst component (a) comprises a solid catalyst component comprising at least a titanium compound having a Ti-halogen bond and an internal electron donor supported on an anhydrous magnesium dihalide support. Such a preferred solid Ziegler-Natta procatalyst component (a) comprises a solid catalyst component comprising titanium tetrahalide. A preferred titanium tetrahalide is TiCl4. Alkoxy halides may also be used in the solid Ziegler-Natta procatalyst component (a).

[0014]

[0014] The internal electron donor for the preparation of the solid Ziegler-Natta procatalyst component (a) can be selected from commonly used internal donors, such as aliphatic / aromatic esters, phthalic acid esters, aliphatic / aromatic 1,3-diethers, malonic acid esters, succinic acid esters, and carbonate compounds.In some embodiments, the internal donor is di-isobutyl phthalate, di-n-butyl phthalate, di-iso-octyl phthalate, 1,3-dipentyl phthalate, ethyl benzoate, ethyl benzoate, n-butyl benzoate, methyl-p-toluate, and methyl-p-methoxybenzoate and diisobutyl phthalate, diethyl diisobutyl malonate, diethyl isopropyl malonate, diethyl phenyl malonate, dimethyl diisobutyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, dimethyl phenyl malonate, methyl ... Phenylmalonate, 9,9-bis(methoxymethyl)fluorene;9,9-bis(methoxymethyl)-2,3,6,7-tetramethylfluorene;9,9-bis(methoxymethyl)-2,3,4,5,6,7-hexafluorofluorene;9,9-bis(methoxymethyl)-2,3-benzofluorene;9,9-bis(methoxymethyl)-2,3,6,7-dibenzofluorene;9,9-bis(methoxymethyl)-2,7-diisopropylfluorene;9,9-bis(methoxymethyl)-1 ,8-Dichlorofluorene;9,9-Bis(methoxymethyl)-2,7-dicyclopentylfluorene;9,9-Bis(methoxymethyl)-1,8-difluorofluorene;9,9-Bis(methoxymethyl)-1,2,3,4-tetrahydrofluorene;9,9-Bis(methoxymethyl)-1,2,3,4,5,6,7,8-octahydrofluorene;9,9-Bis(methoxymethyl)-4-tert-butylfluorene, diethyl 2,3-bis(trimethylsilyl)succinate, diethyl The internal electron donor may be selected from the group consisting of diethyl 2,3-bis(2-ethylbutyl)succinate, diethyl 2,3-dibenzylsuccinate, diethyl 2,3-diisopropylsuccinate, diisobutyl 2,3-diisopropylsuccinate, diethyl 2,3-bis(cyclohexylmethyl)succinate, diethyl 2,3-diisobutylsuccinate, diethyl 2,3-dineopentylsuccinate, diethyl 2,3-dicyclopentylsuccinate, and diethyl 2,3-dicyclohexylsuccinate. Other common internal electron donors, such as alkyl or alkyl-aryl ethers, polyethers, ketones, mono- or polyamines, heterocyclic organic compounds, aldehydes, and P-containing compounds, such as phosphines and phosphoramides, may also be used.

[0015]

[0015] Acceptable anhydrous magnesium dihalides that form the support of the solid Ziegler-Natta pro-catalyst component (a) are magnesium dihalides in the active form well-known in the art. Such magnesium dihalides may be pre-activated, activated in-situ during titanation, or activated after being formed in-situ from a magnesium compound capable of forming magnesium dihalides when treated with a suitable halogen-containing transition metal compound. Preferred magnesium dihalides are magnesium dichloride and magnesium dibromide. The water content of the dihalide is generally less than 1% by weight.

[0016]

[0016] The solid Ziegler-Natta pro-catalyst component (a) can be prepared in various ways. One such method consists of grinding a magnesium dihalide and an internal electron donor compound together until the product exhibits a surface area higher than 20 m 2 / g, and then reacting the ground product with a Ti compound. Other methods for preparing the solid Ziegler-Natta pro-catalyst component (a) are disclosed in U.S. Patent Nos. 4,220,554; 4,294,721; 4,315,835; 4,330,649; 4,439,540; 4,816,433; and 4,978,648. These methods are incorporated herein by reference.

[0017]

[0017] In a typical solid Ziegler-Natta pro-catalyst component (a), the molar ratio of magnesium dihalide to the halogenated titanium compound is 1 to 500, and the molar ratio of the halogenated titanium compound to the internal electron donor is 0.1 to 50.

[0018] Preferred cocatalyst component (b) includes aluminum alkyl compounds. Acceptable aluminum alkyl compounds include aluminum trialkyls, such as aluminum triethyl, aluminum triisobutyl, and aluminum triisopropyl. Other acceptable aluminum alkyl compounds include aluminum dialkyl hydrides, such as aluminum diethyl hydride. Other acceptable cocatalyst components (b) include compounds containing two or more aluminum atoms linked together through heteroatoms, such as: (C2H5)2Al-O-Al(C2H5)2 (C2H5)2Al-N(C6H5)-Al(C2H5)2; and (C2H5)2Al-O-SO2-O-Al(C2H5)2 There is.

[0019] Acceptable external stereoselectivity control agents (SCAs) (c) are organic compounds containing O, Si, N, S, and / or P. Such compounds include organic acids, organic acid esters, organic acid anhydrides, ethers, ketones, alcohols, aldehydes, silanes, amides, amines, amine oxides, thiols, various phosphites and amides, etc. Preferred SCA components (c) are organosilicon compounds containing Si—O—C and / or Si—N—C bonds. Specific examples of such organosilicon compounds are trimethylmethoxysilane, diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, diisopropyldimethoxysilane, dicyclopentyldimethoxysilane, isobutyltriethoxysilane, vinyltrimethoxysilane, dicyclohexyldimethoxysilane, 3-tert-butyl-2-isobutyl-2-methoxy-[1,3,2]oxazasilolidine, 3-tert-butyl-2-cyclopentyl ... oxazasilolidine, 2-bicyclo[2.2.1]hept-5-en-2-yl-3-tert-butyl-2-methoxy-[1,3,2]oxazasilolidine, 3-tert-butyl-2,2-diethoxy-[1,3,2]oxazasilolidine, 4,9-di-tert-butyl-1,6-dioxa-4,9-diaza-5-sila-spiro[4.4]nonane, bis(perhydroisoquinolino)dimethoxysilane, etc. Mixtures of organic electron donors can also be used.

[0020] The olefin polymerization process that can be used in accordance with the present invention is generally not limited. For example, the catalyst components (a), (b), (c), and (d) can be added simultaneously or sequentially to the polymerization reactor when used. It is preferred to first mix components (b), (c), and (d), and then contact the resulting mixture with component (a) prior to polymerization.

[0021] The olefin monomer may be added prior to, along with, or after the addition of the Ziegler-Natta catalyst composition to the polymerization reactor, with the olefin monomer being preferably added after the addition of the Ziegler-Natta catalyst composition.

[0022] The molecular weight of the polymer can be controlled in a known manner, preferably by using hydrogen. With the catalyst produced in accordance with the present invention, molecular weight can be adequately controlled by hydrogen when the polymerization is carried out at a relatively low temperature, for example, from about 30° C. to about 95° C. This molecular weight control can be evidenced by a measurable positive change in the melt flow rate (MFR).

[0023] The polymerization reaction may be carried out in a slurry, liquid or gas phase process, or in a combination of liquid and gas phase processes using separate reactors, either batchwise or continuously. The polyolefin may be obtained directly from a gas phase process, or by isolating and recovering the solvent from a slurry process according to methods known in the art.

[0024]

[0024] There are no particular limitations on the polymerization conditions for producing polyolefins by the method of this invention, such as polymerization temperature, polymerization time, polymerization pressure, monomer concentration, etc. The polymerization temperature is generally 40-90°C, and the polymerization pressure is generally 1 atmosphere or more.

[0025] The Ziegler-Natta catalyst composition of the present invention may be pre-contacted with a small amount of olefin monomer at a temperature of 60° C. or less in a hydrocarbon solvent for a time sufficient to produce polymer in an amount of 0.5 to 5 times the weight of the catalyst, known in the art as pre-polymerization. If such pre-polymerization is carried out with liquid or gaseous monomer, the amount of polymer obtained will generally be 1000 times or less the weight of the catalyst.

[0026] The Ziegler-Natta catalyst compositions of the present invention are useful for the polymerization of olefins, including, but not limited to, the homopolymerization and copolymerization of alpha olefins. Suitable α-olefins that may be used in the polymerization process according to the present invention include those having the general formula CH═CHR, where R is H or C 1-10 The Ziegler-Natta catalyst compositions of the present invention can be used in processes in which ethylene is polymerized, but it is more desirable to use the Ziegler-Natta catalyst compositions of the present invention in processes in which polypropylene or higher olefins are polymerized. Processes involving the homopolymerization or copolymerization of propylene are preferred. [Example]

[0027] To provide a better understanding of the foregoing, the following non-limiting examples are presented. These examples may relate to specific embodiments, but should not be construed as limiting the invention in any particular way. Activity values (AC) are based on grams of polymer produced per gram of solid catalyst component used.

[0028] The following analytical methods are used to characterize the polymers:

[0029] Heptane insolubles (HI%): weight percent (wt%) of the residue of a polypropylene sample after being extracted with boiling heptane for 8 hours.

[0029]

[0030] Melt flow rate (MFR): ASTM D-1238, determined at 230°C under a load of 2.16 kg.

[0031] Magnesium ethoxide (98%), anhydrous toluene (99.8%), TiCl4 (99.9%), anhydrous n-heptane (99%), diisobutyl phthalate (99%), cyclohexyl(dimethoxy)methylsilane (C-donor, ≥99%), and triethylaluminum (93%) were all purchased from Sigma-Aldrich Co. of Milwaukee, WI, USA. Diisopropyldimethoxysilane (P-donor) was purchased from Gelest, Inc. of Morrisville, PA, USA. 2-Ethoxyethyl ethyl carbonate and 2-isopropyl-2-(1-methylbutyl)-1,3-dimethoxypropane were provided by Toho Titanium Co., Ltd. Diethyl carbonate (98%) and di-n-butyl carbonate (98%) were purchased from TCI America.

[0032] Unless otherwise noted, all reactions were conducted under an inert atmosphere.

[0030] Example 1 (A) Preparation of solid catalyst component (A-1)

[0033] A three-necked 250 ml flask equipped with a fritted filter disc and a mechanical stirrer, thoroughly purged with nitrogen, was charged with 80 mmol of magnesium ethoxide and 80 ml of anhydrous toluene to form a suspension. 20 ml of TiCl4 was added to the suspension, and the reaction mixture was then heated to 90°C. 10 mmol of diisobutyl phthalate (DIBP) was added as an internal electron donor, followed by heating to 110°C and stirring at that temperature for 2 hours. After completion of the reaction, the resulting solid was filtered and washed twice with 100 ml of anhydrous toluene at 90°C. 80 ml of fresh anhydrous toluene and 20 ml of TiCl4 were added and the reaction was continued for an additional 2 hours at 110°C with stirring. After completion of the reaction, the solid was filtered, washed seven times with 100 ml of anhydrous n-heptane at 90°C, and dried under reduced pressure to obtain solid composition (A-1).

[0031] (B) Propylene Slurry Polymerization

[0034] Propylene polymerizations were carried out in a bench-scale 2-liter reactor according to the following procedure.

[0032]

[0035] The reactor was first preheated to at least 100°C under a nitrogen purge to remove residual moisture and oxygen. The reactor was then cooled to 50°C. One liter of dry heptane was introduced into the reactor under nitrogen. When the reactor temperature reached approximately 50°C, 4.3 ml of triethylaluminum (0.6 M in hexane), 0.4 ml of diisopropyl(dimethoxy)silane (P-donor) (0.5 M in heptane), 1.0 ml of diethyl carbonate solution (0.3 M in heptane), and then 30 mg of the solid catalyst component (A-1) prepared above were added to the reactor. The reactor temperature was then heated to 50°C, and 30 psi of hydrogen from a 150 ml container was flushed into the reactor along with propylene.

[0033]

[0036] The reactor temperature was then increased to above 70°C. The total reactor pressure was increased and controlled at 620528.4 Pa (90 psig) by continuously introducing propylene into the reactor, and polymerization was allowed to proceed for 1 hour. After polymerization, the reactor was vented to reduce the pressure to 0 Pa (0 psig), and the reactor temperature was cooled to 50°C. The reactor was then opened. 500 ml of methanol was added to the reactor, and the resulting mixture was stirred for 5 minutes and then filtered to obtain the polymer product. The resulting polymer was dried under vacuum at 80°C for 6 hours.

[0037] The polymer melt flow rate (MFR) and heptane insoluble content (HI%) were evaluated. The catalyst activity (AC) was also measured. The results are shown in Table 1.

[0034] Example 2 (B) Propylene Slurry Polymerization

[0038] Propylene polymerization using catalyst component (A-1) was carried out in the same manner as described in Example 1, except that 1.0 ml of di-n-butyl carbonate solution (0.3 M, in heptane) was used instead of 1.0 ml of diethyl carbonate solution (0.3 M, in heptane). The results are shown in Table 1.

[0035] Example 3 (B) Propylene Slurry Polymerization

[0039] Propylene polymerization using catalyst component (A-1) was carried out in the same manner as described in Example 1, except that 0.67 ml of 2-ethoxyethyl ethyl carbonate (0.3 M, in heptane) was used instead of 1.0 ml of diethyl carbonate solution (0.3 M, in heptane). The results are shown in Table 1.

[0036] Example 4 (A) Preparation of solid catalyst component (A-2)

[0040] A solid catalyst component (A-2) was prepared in the same manner as in Example 1, except that 7.5 mmol of 2-isopropyl-2-(1-methylbutyl)-1,3-dimethoxypropane and 7.5 mmol of diethyl 2,3-diisopropylsuccinate were added instead of 10 mmol of diisobutyl phthalate (DIBP) as the internal electron donor to prepare the catalyst component (A-2).

[0037] (B) Propylene Slurry Polymerization

[0041] Propylene polymerization using catalyst component (A-2) was carried out in the same manner as described in Example 1, except that 0.67 ml of a diethyl carbonate solution (0.3 M in heptane) was charged and hydrogen at 68947.6 Pa (10 psi) in a 150 ml vessel was flushed into the reactor together with propylene. The results are shown in Table 1.

[0038] Comparative Example 1 (B) Propylene Slurry Polymerization

[0042] Except for not adding diethyl carbonate, propylene polymerization was carried out using catalyst component (A-1) in the same manner as described in Example 1. The results are shown in Table 1.

[0039] Comparative Example 2 (B) Propylene bulk polymerization

[0043] Propylene polymerization using catalyst component (A-2) was carried out in the same manner as in Example 4, except that diethyl carbonate was not added. The results are shown in Table 1.

[0040] [Table 1]

[0041]

[0044] As is evident from the above results shown in Table 1, by using a carbonate compound as an activity-limiting agent (ALA) in accordance with the teachings of the present invention, reduced polymerization activity was achieved at elevated polymerization temperatures. This is compared and contrasted with the use of a silane (SCA) compound alone and the use of the same SCA / ALA mixture at lower polymerization temperatures. For example, in Table 1, the polymerization activity at 100°C for Examples 1, 2, and 3 is approximately 40% of the activity at 70°C for Comparative Example 1, while without a carbonate compound as the ALA, the polymerization activity at 100°C is approximately 60% of the activity at 70°C. Also, the polymerization activity at 100°C for Example 4 is 27% of the activity at 70°C for Comparative Example 2, while without a carbonate compound as the ALA, the polymerization activity at 95°C is approximately 50% of the activity at 70°C. These demonstrate that the compositions possess self-limiting polymerization properties. Also, as one skilled in the art will appreciate from the data, the presence of a carbonate compound as ALA in the catalyst composition improves polymer isotacticity (HI %) compared to the corresponding comparative example.

[0042]

[0045] In yet another embodiment of the present invention, there is provided a catalyst composition for the polymerization of olefins, preferably propylene, comprising one or more Ziegler-Natta procatalyst components comprising magnesium, titanium, a halogen, and one or more internal electron donors; one or more aluminum-containing cocatalysts; and one or more activity limiting agents (ALAs) comprising one or more alkyl-, cycloalkyl-, or aryl carbonates and derivatives thereof.

[0043]

[0046] In a preferred aspect of this embodiment, at least one of the one or more ALAs has formula I: R 1 OC(=O)OR 2 [Formula I] (R in the formula1 and R2 are independently selected from hydrogen, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 4 to 20 carbon atoms, or a heteroatom-containing hydrocarbon group having 1 to 20 carbon atoms; R 1 and R2 may be linked to form one or more saturated or unsaturated monocyclic or polycyclic rings).

[0044]

[0047] In a preferred aspect of this embodiment, the one or more ALAs in the catalyst composition are diethyl carbonate, di-n-butyl carbonate, or 2-ethoxyethyl ethyl carbonate, although it is contemplated that the one or more ALAs may be selected from dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, di-n-butyl carbonate, propylene carbonate, 2-ethoxyethyl ethyl carbonate, didodecyl carbonate, diphenyl carbonate, t-butylphenyl carbonate, bis(4-chlorophenyl)carbonate, 3,4-dichlorobenzylhexyl carbonate, ethylene glycol bis-(methyl carbonate), or diethyl 2,5-dioxahexanedioate.

[0045]

[0048] In a preferred aspect of this embodiment, the catalyst composition may further comprise one or more external stereoselectivity control agents (SCAs), which are preferably compounds containing a Si—O—C or Si—N—C bond, wherein silicon is the central atom of the compound.

[0046]

[0049] Following these teachings, the resulting polymerization activity at 100°C is less than 43% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs, or less than 39% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs, or less than 37% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs, or less than 27% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs.

[0047]

[0050] In yet another embodiment of the present invention, a method for polymerizing olefins, preferably propylene, utilizing the catalyst composition described above is disclosed, wherein, according to some teachings of the present disclosure, the polymerization activity obtained at 100°C is less than 43% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs, or less than 39% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs, or less than 37% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs, or less than 27% of the polymerization activity at 70°C of the catalyst composition not containing one or more ALAs.

[0048]

[0051] Thus, the present invention is well adapted to attain the ends and advantages mentioned, as well as those inherent therein. The particular embodiments disclosed above are merely illustrative, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the specific exemplary embodiments disclosed above may be altered or modified, and all such variations are considered within the scope and spirit of the invention. Whenever a numerical range with a lower and upper limit is disclosed, every number within that range is specifically disclosed. Furthermore, the indefinite article "a" or "an," as used in the claims, is defined herein to mean one or more of the element it refers to.

Claims

1. 1. A catalyst composition for the polymerization of olefins, comprising: one or more Ziegler-Natta procatalyst components comprising magnesium, titanium, a halogen, and one or more internal electron donors; one or more aluminum-containing cocatalysts; and one or more activity limiting agents (ALA) including one or more alkyl-, cycloalkyl-, or aryl carbonates and derivatives thereof; A catalyst composition comprising:

2. At least one of the one or more ALAs has Formula I: R １ OC(=O)OR ２ Formula I (In the formula R １ and R ２ are independently selected from hydrogen, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 4 to 20 carbon atoms, or a heteroatom-containing hydrocarbon group having 1 to 20 carbon atoms; R １ and R ２ may be linked to form one or more saturated or unsaturated monocyclic or polycyclic rings.

2. The catalyst composition of claim 1, wherein:

3. 2. The catalyst composition of claim 1, wherein the one or more ALAs are selected from: dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, di-n-butyl carbonate, propylene carbonate, 2-ethoxyethyl ethyl carbonate, didodecyl carbonate, diphenyl carbonate, t-butylphenyl carbonate, bis(4-chlorophenyl)carbonate, 3,4-dichlorobenzylhexyl carbonate, ethylene glycol bis-(methyl carbonate), or diethyl 2,5-dioxahexanedioate.

4. 10. The catalyst composition of claim 1, wherein the one or more ALAs comprise diethyl carbonate.

5. 10. The catalyst composition of claim 1, wherein the one or more ALAs comprise di-n-butyl carbonate.

6. 10. The catalyst composition of claim 1, wherein the one or more ALAs comprise 2-ethoxyethyl ethyl carbonate.

7. The catalyst composition of claim 1 wherein the olefin comprises propylene.

8. 10. The catalyst composition of claim 1, further comprising one or more external stereoselectivity control agents (SCAs).

9. 9. The catalyst composition of claim 8, wherein at least one of said SCAs is a compound containing a Si--O--C or Si--N--C bond, and silicon is the central atom of said compound.

10. 10. The catalyst composition of claim 1, wherein the resulting polymerization activity at 100°C is less than 43% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

11. 10. The catalyst composition of claim 1, wherein the resulting polymerization activity at 100°C is less than 39% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

12. 10. The catalyst composition of claim 1, wherein the resulting polymerization activity at 100°C is less than 37% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

13. 10. The catalyst composition of claim 1, wherein the resulting polymerization activity at 100°C is less than 27% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

14. 1. A method for polymerizing olefins, comprising: providing a catalyst composition comprising one or more Ziegler-Natta procatalyst components comprising magnesium, titanium, a halogen, and one or more internal electron donors; one or more aluminum-containing cocatalysts; and one or more activity limiting agents (ALA) comprising one or more alkyl-, cycloalkyl-, or aryl carbonates and derivatives thereof; reacting an olefin with said catalyst composition to form a polyolefin. A method comprising:

15. At least one of the one or more ALAs has Formula I: R １ OC(=O)OR ２ Formula I (In the formula R １ and R ２ are independently selected from hydrogen, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 4 to 20 carbon atoms, or a heteroatom-containing hydrocarbon group having 1 to 20 carbon atoms; R １ and R ２ may be linked to form one or more saturated or unsaturated monocyclic or polycyclic rings. The method of claim 14, wherein the

16. 15. The method of claim 14, wherein the one or more ALAs are selected from: dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, di-n-butyl carbonate, propylene carbonate, 2-ethoxyethyl ethyl carbonate, didodecyl carbonate, diphenyl carbonate, t-butylphenyl carbonate, bis(4-chlorophenyl)carbonate, 3,4-dichlorobenzylhexyl carbonate, ethylene glycol bis-(methyl carbonate), or diethyl 2,5-dioxahexanedioate.

17. 15. The method of claim 14, wherein the one or more ALAs comprise diethyl carbonate.

18. 15. The method of claim 14, wherein the one or more ALAs comprise di-n-butyl carbonate.

19. 15. The method of claim 14, wherein the one or more ALAs comprise 2-ethoxyethyl ethyl carbonate.

20. 15. The method of claim 14, wherein the olefin comprises propylene.

21. 15. The method of claim 14, further comprising one or more external stereoselectivity control agents (SCAs).

22. 22. The method of claim 21, wherein at least one of the SCAs is a compound containing a Si-O-C or Si-N-C bond, and silicon is the central atom of the compound.

23. 15. The process of claim 14, wherein the resulting polymerization activity at 100°C is less than 43% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

24. 15. The process of claim 14, wherein the resulting polymerization activity at 100°C is less than 39% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

25. 15. The process of claim 14, wherein the resulting polymerization activity at 100°C is less than 37% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

26. 15. The process of claim 14, wherein the resulting polymerization activity at 100°C is less than 27% of the polymerization activity at 70°C of a catalyst composition that does not contain the one or more ALAs.

Images