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US 5,288,933 AGranted
Process for the production of polyethylene
AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsSun-Chueh Kao, Frederick J. Karol
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AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsSun-Chueh Kao, Frederick J. Karol
Estimating the term…
A process for the polymerization of ethylene or a mixture comprising ethylene and one or more alpha-olefins and, optionally, a diene, comprising passing, under polymerization conditions, the aforementioned monomer(s) into contact with a catalyst system comprising: (a) the reaction product of (i) a titanium based catalyst precursor having the formula Mg.sub.a Ti(OR).sub.b X.sub.c (ED).sub.d wherein ED is an inside electron donor comprising a mixture of (A) about 1 to about 80 mole percent of an alkyl, alkoxy, aryl, or aryloxy phosphine oxide, or mixtures thereof, and (B) about 20 to about 99 mole percent of an organic ester, ether, or ketone, or mixtures thereof, said phosphine oxide also being present in a molar ratio of phosphine oxide to titanium of 0.1:1 to 8:1; R is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms of COR' wherein R' is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms; each OR group is the same or different; each X is independently chlorine, bromine, or iodine; wherein component (a) is impregnated into an inorganic support; and (b) a hydrocarbyl aluminum cocatalyst.
A process for the polymerization of ethylene or a mixture comprising ethylene and one or more alpha-olefins and, optionally, a diene, comprising passing, under polymerization conditions, the aforementioned monomer(s) into contact with a catalyst system comprising:
A process for the polymerization of ethylene or a mixture comprising ethylene and one or more alpha-olefins having 3 to 8 carbon atoms and, optionally, a diene, comprising passing, under polymerization conditions, the aforementioned monomer(s) into contact with a catalyst system comprising:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond: ethene
Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
Term ended 16 Apr 2012 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates to a process for the production of polyethylene having a relatively low melt flow ratio.
The catalyst system disclosed in U.S. Pat. No. 4,302,565 includes a precursor containing magnesium, titanium, a halogen, and an electron donor, and is found to be quite useful in the production of polymers, which are advantageously used in injection molding. These polymers are characterized by relatively high densities, low melt flow ratios, and narrow molecular weight distributions, and the catalyst system is characterized by high activity. Melt flow ratio is the ratio of flow index to melt index. Melt index is determined under ASTM D-1238, Condition E. It is measured at 190.degree. C. and reported as grams per 10 minutes. Flow index is determined under ASTM D-1238, Condition F. It is measured at 10 times the weight used in the melt index text above and reported in the same manner, i.e., grams per 10 minutes.
While the characteristics of the catalyst system and the polymers produced using same are of commercial significance, there is a need for a catalyst system which can provide polymers having still lower melt flow ratios and, when molded or extruded, improved physical properties including higher dart drop, lower hexane extractables, and high impact strength, without sacrifice in the high activity aspect of the catalyst system or even with some improvement.
The titanium based catalyst and its method for preparation, except with respect to the phosphine oxide, are disclosed in U.S. Pat. No. 4,302,565, mentioned above. The catalyst precursor can be prepared from a titanium compound, a magnesium compound, and an electron donor.
Titanium compounds, which are useful in preparing these precursors, have the formula Ti(OR).sub.b X.sub.h wherein R, X and b are as defined above for component (a); h is an integer from 1 to 4; and b+h is 3 or 4. Examples of titanium compounds are TiCl.sub.3, TiCl.sub.4, Ti(OC.sub.2 H.sub.5).sub.2 Br.sub.2, Ti(OC.sub.5 H.sub.5)Cl.sub.3, Ti(OCOCH.sub.3)Cl.sub.3, and Ti(OCOC.sub.6 H.sub.5)Cl.sub.3.
The magnesium compounds, useful in preparing the precursors, include magnesium halides such as MgCl.sub.2, MgBr.sub.2, and MgI.sub.2. Anhydrous MgCl.sub.2 is a preferred compound. About 0.5 to 56, and preferably about 1 to 10, moles of the magnesium compounds are used per mole of titanium compounds. The halogen and OR groups, if any, are found in the magnesium and titanium compounds.