USOO6337297B1 (12) United States Patent (10) Patent No.: US 6,337,297 B1 Mimura et al. (45) Date of Patent: Jan. 8, 2002 (54) CATALYST FOR TRIMERIZATION OF 5,780,698 A 7/1998 Barat et al. ETHYLENE AND PROCESS FOR 5,891.816 A * 4/1999 Wang et al. .................. 502/117 TRIMERIZING ETHYLENE USING THE 6,180,552 B1 * 1/2001 Hlatky .......................... 502/117 CATALYST 6,197.901 B1 * 3/2001 Rohde et al. ................. 502/117 FOREIGN PATENT DOCUMENTS (75) Inventors: Hideyuki Mimura, Shinnanyo; Motohiro Oguri, Yokkaichi; Toshihide JP 10-7712 1/1998 Yamamoto, Yokkaichi; Hideyuki JP 10-71335 3/1998 Murakita, Yokkaichi; Hisanori Okada, JP 10-231.317 9/1998 Yokkaichi, Toru Yoshida, Kuwana, all JP 10-287690 10/1998 of (JP) JP 11-60627 3/1999 * cited by examiner (73) Assignee: Tosoh Corporation, Shinnanyo (JP) Primary Examiner Mark L. Bell (*) Notice: Subject to any disclaimer, the term of this Assistant Examiner J. Pasteczyk patent is extended or adjusted under 35 (74) Attorney, Agent, or Firm-Oblon, Spivak, McClelland, U.S.C. 154(b) by 0 days. Maier & Neustadt, P.C. (57) ABSTRACT (21) Appl. No.: 09/457,522 A catalyst for trimerization of ethylene is disclosed which (22) Filed: Dec. 9, 1999 comprises (a) a chromium complex having a neutral multi (30) Foreign Application Priority Data dentate ligand having a tripod Structure, represented by the formula, ACrJOs, wherein A is a neutral multidentate Oct. 12, 1998 (JP) ................................................. 1O-351134 ligand having a tripod Structure, J is a carbonyl ligand or Nov. 12, 1998 (JP) ................................................. 1O-352540 halogen, n is an integer of 0–3, and Q is at least one member (51) Int. Cl. ............................. B01J 31/00; B01J 37/00; Selected from hydrogen, a C-C hydrocarbon group, a CO8F 4/02; CO8F 4/60; CO7C 2/58 C-Clo carboxylate group, a C-Co diketonato group, an amide group, an imide group, an C-Clio alkoxide group, a (52) U.S. Cl. .......................... 502/117; 585/721; 585/722; C-Co thioalkoxide group, an C-Cs arene ligand, an 585/726; 585/727; 585/730; 585/732; 502/123; C-Clio alkene ligand, an C-C is alkyne ligand, an amine 502/167; 502/168; 502/169; 502/170 ligand, an imine ligand, an isonitrile ligand, a phosphine (58) Field of Search ............................. 502/117; 585/721, ligand, a phosphine oxide ligand, a phosphite ligand, an 585/722, 726, 727, 730, 732 ether ligand, a Sulfide ligand, a Sulfone ligand and a Sulfox ide ligand, and (b) a metal alkyl compound. The catalyst (56) References Cited optionally further comprises (c) at least one compound U.S. PATENT DOCUMENTS Selected from aromatic tertiary amine compounds, except for an imine, and nitrogen-containing heterocyclic 3,033,878 A 5/1962 Zeiss et al. ................... 502/117 3,149,080 A * 9/1964 Gluesenkamp et al. ..... 502/117 compounds, and (d) a radical anion compound. 3.223,688 A 12/1965 Badin ................... ... 502/117 3,316,235 A 4/1967 Yazima et al. ............... 502/117 13 Claims, No Drawings US 6,337,297 B1 1 2 CATALYST FOR TRIMERIZATION OF Such that it has a poor Solubility in an organic Solvent and the ETHYLENE AND PROCESS FOR catalyst is troubleSome to prepare, and further that it is not TRIMERIZING ETHYLENE USING THE readily commercially available and is expensive. CATALYST The catalyst of JP-AH6-298673 has a problem such that BACKGROUND OF THE INVENTION alminoxane used as one ingredient of the catalyst is difficult to Synthesize with a good reproducibility. The catalyst of (1) Field of the Invention JP-A H10-7712 has a poor activity for trimerization of This invention relates to a catalyst for trimerization of ethylene. The catalyst of JP-AH10-231317 has problems ethylene and a process for trimerizing ethylene using the Such that polyethylene is undesirably produced in an amount catalyst. More Specifically, it relates to a catalyst exhibiting larger than that of 1-hexene, and that the Selectivity to an enhanced activity for trimerization of ethylene to produce 1-hexene among oligomerS is low. 1-hexene, which is used as a comonomer for the production of linear low-density polyethylene (LLDPE), and further to SUMMARY OF THE INVENTION a process for trimerizing ethylene by which 1-hexene can be 15 In View of the foregoing, a primary object of the present produced effectively and highly Selectively. invention is to provide a catalyst having good handling (2) Related Art characteristics and exhibiting an enhanced activity for tri It is known to use a chromium compound as a catalyst for merization of ethylene to produce 1-hexene, which is used trimerization of ethylene to give 1-hexene. For example, a as a comonomer for the production of linear low-density catalyst System comprising a chromium compound, polyhy polyethylene (LLDPE). drocarbylaluminum oxide and a donor ligand is described in Another object of the present invention is to provide a Japanese Unexamined Patent Publication No. (hereinafter process for trimerizing ethylene by which 1-hexene can be abbreviated to “JP-A”) S62-265237. A catalyst system com produced effectively and highly Selectively. prising a chromium compound, a pyrrole-containing 25 In one aspect of the present invention, there is provided a compound, an alkyl metal compound and a halide is catalyst for trimerization of ethylene which comprises: described in JP-AH6-23.9920. A catalyst system comprising (a) a chromium complex having a neutral multidentate a chromium compound, an alkyl metal compound, and an ligand having a tripod Structure, represented by the acid amide or imide compound is described in JP-A following formula (1): HB-59732. A catalyst comprising (i) a complex of chro mium Salt with a multidentate ligand Selected from ACrO3, (1) phosphine, arsine and stibine, and (ii) aluminoxane is wherein A is a neutral multidentate ligand having a described in JP-AH6-298673. A catalyst comprising (i) a 35 tripod structure, J is a carbonyl ligand or a halogen chromium-chlorine complex or alkyl chromium complex atom, n is an integer of 0 to 3, and Q is at least one having a specific nitrogen ligand and (ii) an aluminum member Selected from the group consisting of a hydro compound is described in JP-AH10-7712. A catalyst com gen atom, a hydrocarbon group having 1 to 10 carbon prising (i) a chromium complex having a cyclic polyamine atoms, a carboxylate group having 1 to 10 carbon or hydro-tris(pyrazolyl)borate ligand and (ii) an alkyl alu 40 atoms, a diketonato group having 3 to 10 carbon atoms, minum compound is described in JP-AHIO-231317. an amide group, an imide group, an alkoxide group having 1 to 10 carbon atoms, a thioalkoxide group However, these chromium catalysts have problems as having 1 to 10 carbon atoms, an arene ligand having 6 explained below. to 15 carbon atoms, an alkene ligand having 2 to 10 When the catalyst of JP-A S62-265237 is used for trim 45 carbon atoms, an alkyne ligand having 2 to 15 carbon erization of ethylene, a Salient amount of polyethylene is atoms, an amine ligand, an imine ligand, a nitrile produced in addition to 1-hexene. Further, polyhydrocarbyl ligand, an isonitrile ligand, a phosphine ligand, a phos aluminum oxide (i.e., aluminoxane), which is one ingredient phine oxide ligand, a phosphite ligand, an ether ligand, of the catalyst, is a polymer prepared by reacting an alkyl a Sulfide ligand, a Sulfone ligand and a Sulfoxide ligand, 50 and aluminum with water, and therefore, it is difficult to prepare (b) a metal alkyl compound. aluminoxane having a predetermined quality, and this leads Preferably the catalyst further comprises (c) at least one to reduction of reproducibility of trimerization reaction of compound Selected from aromatic tertiary amine ethylene. compounds, except for an imine, and nitrogen-containing When the catalyst of JP-AH6-23.9920 is used, the amount 55 heterocyclic compounds, and/or (d) a radical anion com of polyethylene produced can be reduced. However, a pound. pyrrole-containing compound, which is one ingredient of the In another aspect of the present invention, there is pro catalyst, is extremely unstable to air, and readily deteriorated Vided a process for trimerizing ethylene, characterized in and colored. Thus, a pyrrole-containing compound is that ethylene is trimerized in the presence of the above troublesome to handle, and a treating process or apparatus 60 mentioned catalyst. for removing a coloring matter from the catalyst or purifying DESCRIPTION OF THE PREFERRED the catalyst is needed. EMBODIMENTS As for the catalyst of JP-A H8-59732, among the acid amide or imide compounds, which are one ingredient of the 65 Catalyst for Trimerization of Ethylene catalyst, maleimide is optimum for the catalytic activity for The catalyst of the invention comprises a chromium trimerization of ethylene. However, maleimide has problems complex having a neutral multidentate ligand having a US 6,337,297 B1 3 4 tripod structure, represented by the above formula (1) as one may have a Substituent on the ring thereof, Such as, for indispensable ingredient. The neutral multidentate ligand example, methyl, ethyl, propyl, butyl, octyl and phenyl. having a tripod Structure coordinated in the chromium R" in formula (2) is not particularly limited, and include, complex is not particularly limited, and includes, for for example, a hydrogen atom, alkyl groups having 1 to 10 example, those which are represented by the following carbon atoms Such as methyl, ethyl, propyl, butyl, benzyl, formulae (2) and (3). hydroxymethyl, cyanoethyl, allyl and trifluoropropyl, and aryl groups having 6 to 10 carbon atoms Such as phenyl, (2) p-methylphenyl and p-chlorophenyl.