Polyethylene and process for production thereof
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
C08F-004/642
C08F-004/6592
C08F-210/02
출원번호
US-0275680
(2011-10-18)
등록번호
US-8436114
(2013-05-07)
발명자
/ 주소
Crowther, Donna J.
Fiscus, David M.
출원인 / 주소
ExxonMobil Chemical Patents Inc.
대리인 / 주소
Faulkner, Kevin M.
인용정보
피인용 횟수 :
1인용 특허 :
24
초록▼
This invention relates to a process for polymerizing olefins in which the amount of trimethylaluminum in a methylalumoxane solution is adjusted to be from 1 to 25 mol %, prior to use as an activator, where the mol % trimethylaluminum is determined by 1H NMR of the solution prior to combination with
This invention relates to a process for polymerizing olefins in which the amount of trimethylaluminum in a methylalumoxane solution is adjusted to be from 1 to 25 mol %, prior to use as an activator, where the mol % trimethylaluminum is determined by 1H NMR of the solution prior to combination with any support. This invention also relates to a process for polymerizing olefins in which the amount of an unknown species present in a methylalumoxane solution is adjusted to be from 0.10 to 0.65 integration units prior to use as an activator, where the amount of the unknown species is determined by the 1H NMR spectra of the solution performed prior to combination with any support. Preferably, the methylalumoxane solution is present in a catalyst system also comprising a metallocene transition metal compound.
대표청구항▼
1. A process for adjusting the properties of a linear low density polyethylene while polymerizing ethylene and hexene to produce a linear low density polyethylene in which the amount of trimethylaluminum in a methylalumoxane solution is reduced within the range from 25 mole % to 1 mole % at a given
1. A process for adjusting the properties of a linear low density polyethylene while polymerizing ethylene and hexene to produce a linear low density polyethylene in which the amount of trimethylaluminum in a methylalumoxane solution is reduced within the range from 25 mole % to 1 mole % at a given hydrogen concentration in order to decrease the weight percent of medium density polyethylene component produced, prior to use as an activator, where the mol % trimethylaluminum is determined by 1H NMR, on the basis of the aluminum content, of the solution prior to combination with any support and wherein the methylalumoxane solution contains at least 2 mol % MAO; and wherein: 1) the methylalumoxane solution is present in a catalyst system also comprising a hafnium metallocene transition metal compound and a support;2) the catalyst system, prior to combination with the support, has an aluminum to transition metal molar ratio of 175:1 or less;3) the olefins comprise ethylene; and4) an ethylene polymer comprising ethylene units and from 0.5 to 25 mol % of at least one C3 to C20 olefin comonomer is obtained, said polymer having an triad content of 0.0001 mol % or more. 2. The process of claim 1, wherein the amount of trimethylaluminum is adjusted by removing trimethylaluminum. 3. The process of claim 1, wherein the catalyst system in methylalumoxane solution prior to combination with any support has an aluminum to transition metal molar ratio of 175:1 to 50:1. 4. The process of claim 1, wherein the metallocene transition metal compound is represented by the formula: CpACpBHfX*n wherein each X* and each Cp group is chemically bonded to Hf, n is 1 or 2, CpA and CpB may be the same or different cyclopentadienyl ligands or ligands isolobal to cyclopentadienyl, either or both of which may contain heteroatoms and either or both of which may be substituted. 5. The process of claim 4, wherein CpA and CpB are independently selected from the group consisting of cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl, and substituted derivatives of each. 6. The process of claim 1, wherein the metallocene transition metal compound comprises a bis(n-C3-4 alkyl cyclopentadienyl) hafnium dialkyl or dihalide. 7. The process of claim 1, wherein the metallocene transition metal compound comprises bis(n-propyl cyclopentadienyl) hafnium dichloride and/or bis(n-propyl cyclopentadienyl) hafnium dimethyl. 8. The process of claim 1, wherein the catalyst system is contacted with one or more olefins. 9. The process of claim 8, wherein the polymerization process is a gas phase process. 10. The process of claim 9, wherein the olefins comprise ethylene and the ethylene partial pressure in the gas phase polymerization is from 50 to 250 psi (345 to 1724 kPa). 11. The process of claim 8, wherein the polymerization process is a slurry phase process. 12. The process of claim 8, wherein the olefins comprise ethylene and at least one C3 to C12 alpha olefin. 13. The process of claim 12, wherein the C3 to C12 alpha olefin is one or more of propylene, butene, hexene, and octene. 14. The process of claim 12, wherein the C3 to C12 alpha olefin is hexene. 15. The process of claim 1, wherein the amount of trimethylaluminum is adjusted by adding trimethylaluminum to the methylalumoxane solution.
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이 특허에 인용된 특허 (24)
Van Dun,Jozef J.; Schouterden,Patrick J. C.; Sehanobish,Kalyan; van den Berghen,Peter F.; Jivraj,Noorallah; Vanvoorden,Johan; Nicasy,Ruddy A. J.; Dixit,Ravi S.; Gemoets,Frederik E., Bimodal polyethylene composition and articles made therefrom.
Luo,Lubin; Sangokoya,Samuel A.; Diefenbach,Steven P.; Strickler,Jamie R.; Bauch,Christopher G., Haloaluminoxane compositions, their preparation, and their use in catalysis.
Stehling Ferdinand C. (Baytown TX) Speed Charles S. (Dayton TX) Welborn ; Jr. Curtis H. (Houston TX), Linear ethylene interpolymer blends of interpolymers having narrow molecular weight and composition distribution.
Ewen, John A.; Elder, Michael J.; Jones, Robert L., Metallocene compounds, process for their preparation and their use in catalytic systems for the polymerization of olefins.
Canich Jo Ann M. (Webster TX) Licciardi Gary F. (Humble TX), Mono-Cp heteroatom containing Group IVB transition metal complexes with MAO: supported catalysts for olefin polymerizati.
Larry D. Cady ; Christopher J. Frye FR; Philip Howard GB; Teresa P. Karjala ; Peter J. Maddox FR; Ian M. Munro ; Deepak R. Parikh ; S. Roy Partington GB; Kevin P. Peil ; Lee Spencer ; Willi, Polyolefin composition with molecular weight maximum occurring in that part of the composition that has the highest comonomer content.
Deavenport Dennis L. (Seabrook TX) Hodges ; III. James T. (Alvin TX) Malpass Dennis B. (Peekskill NY) Tran Nam H. (Houston TX), Preparation of aluminoxanes.
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