Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-02-07
2002-08-13
Teskin, Fred (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S114000, C526S124300, C526S308000, C526S348000, C526S348200
Reexamination Certificate
active
06433119
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a polymetallic supported catalyst component, to a method of preparing the polymetallic supported catalyst component, to the Ziegler-Natta catalyst prepared from the component, to a method of polymerizing at least one alpha-olefin of the formula CH
2
═CHR where R is H or a C
1-12
branched or straight chain alkyl or unsubstituted or substituted cycloalkyl and to the olefin polymers produced using the catalyst.
BACKGROUND OF THE INVENTION
The polymerization of alpha olefins, particularly propylene, with Ziegler-Natta catalysts, comprising the reaction products of organometallic compounds with transition metal compounds, to produce highly crystalline isotactic polymers is known. Typically the highly crystalline isotactic fraction was separated from the amorphous and low molecular weight and semi-crystalline fractions by extraction with a hydrocarbon solvent, such as hexane or kerosene. Since the advent of these catalysts, research activity in this area has generally been concerned with improving the yield, stereospecificity and morphology of the crystalline isotactic polymers. This was achieved with the development of a highly active and highly stereospecific catalyst system comprising TiCl
4
and an electron donor compound (Lewis base) supported on an activated anhydrous MgCl
2
solid catalyst component, and an organoaluminum activator as cocatalyst, with or without an electron donor compound. Typically, the propylene homopolymers produced with this catalyst have an isotacticity of greater than 95% as determined by the number fraction of isotactic pentads from
13
C NMR analysis and a % XSRT of 2 to 5 wherein the ratio of the I.V. of the XSRT fraction to the I.V. of the whole polymer is less than 0.50. Despite the flexibility of this catalyst system, it does not provide certain soft resins having elastic properties or allow production of an atactic polymer of high molecular weight.
U.S. Pat. No. 4,562,170 describes a supported catalyst component for the polymerization of alpha olefins, particularly ethylene, which requires a metal oxide support material from the metals of Groups 2a, 3a, 4 and 4 of the Periodic Table. The supported component is prepared under anhydrous conditions by the sequential steps of forming a slurry of the metal oxide, preferably dehydrated high surface area silica, adding a solution of an organomagnesium compound, adding and reacting a solution of a hafnium compound, adding and reacting a halogenator, adding and reacting a tetravalent titanium compound and recovering the solid catalyst component. It is used with an organoaluminum cocatalyst in the polymerization of ethylene. A similar catalyst system is described in U.S. Pat. Nos. 4,554,265 and 4,618,660 except that the organomagnesium compound in a solution is first reacted with a zirconium compound in a solution rather than a hafnium compound.
U.S. Pat. Nos. 4,578,373 and 4,665,262 relate to supported catalyst component which is quite similar to those described in U.S. Pat. Nos. 4,562,170, 4,554,265 and 4,618,660 discussed above. The primary difference appears to be that a solution of a zirconium compound, hafnium compound or mixtures thereof is used instead of the solution of a hafnium compound or a solution of a zirconium compound.
U.S. Pat. Nos. 4,310,648 and 4,356,111 disclose an olefin polymerization catalyst component prepared by reacting a trivalent or tetravalent titanium compound, a zirconium compound, and organomagnesium compound and a halogen source, such a ethylaluminum dichloride.
SUMMARY OF THE INVENTION
The present invention, in one embodiment, provides a polymetallic supported catalyst component comprising an activated anhydrous MgCl
2
, or alcohol adduct thereof, solid support which has been treated with at least one treatment of at least two halogen-containing transition metal compounds, wherein one is a halogen-containing titanium metal compound and one is a halogen-containing non-titanium transition metal compound, optionally, in the presence of an electron donor.
Another aspect of this invention is the process for producing the polymetallic supported catalyst component comprising treating the activated anhydrous MgCl
2
, alcohol adduct thereof or precursor thereof with at least two treatments of at least two halogen-containing transition metal compounds, one of which is a halogen-containing titanium compound and one of which is a halogen-containing non-titanium transition metal compound, sequentially or simultaneously, optionally, in the presence of a polar, substantially inert solvent in which the metal compounds are at least sparingly soluble and the support is substantially insoluble, and optionally in the presence of an electron donor, initially at 0° C. and then at a temperature from about 30° to about 120° C. for a period of time from 30 to 240 minutes for each treatment, with the solids being isolated in between treatments.
In another embodiment of the invention, a catalyst for the polymerization of at least one alpha-olefin of the formula CH
2
═CHR, where R is H or a C
1-12
branched or straight chain alkyl or substituted or unsubstituted cycloalkyl, is provided by reacting the aforementioned supported catalyst component with an organometallic cocatalyst, optionally in the presence of an electron donor. When substituted, the cycloalkyl is preferably substituted in the 4 position. Typical substituent groups are C
1-13
alkyl or halide or both.
Another aspect of this invention is the polymerization of at least one alpha-olefin having the above formula with the catalyst of this invention.
In yet another embodiment, this invention provides polymers, especially propylene polymers, which have a controllable atactic content, which is expressed herein in terms of its xylene solubility at room temperature (XSRT), and exhibit a ratio of the IV of the xylene soluble fraction to the IV of the bulk polymer greater than or equal to 0.50.
DETAILED DESCRIPTION OF THE INVENTION
The activated anhydrous MgCl
2
support can be prepared by any of the methods disclosed in U.S. Pat. Nos. 4,544,717, 4,294,721, and 4,220,554, the methods of which are incorporated herein by reference.
Alternatively, the solid catalyst support may be prepared by forming an adduct of magnesium dichloride and an alcohol, such as ethanol, propanol, butanol, isobutanol and 2-ethylhexanol, wherein the molar ratio is 1:1 to 1:3, which then treated further according to this invention.
In another method, a magnesium dichloride/alcohol adduct containing generally 3 moles of alcohol per mole of MgCl
2
, may be prepared by mixing the alcohol with the magnesium chloride in an inert hydrocarbon liquid immiscible with the adduct, heating the mixture to the fusion temperature of the adduct while stirring vigorously at 2000-5000 rpm using, for example, an Ultra Turrax T-45 N stirrer. The emulsion thus obtained is cooled quickly to cause the adduct to solidify into spherical particles. The adduct particles are dried and partially dealcoholated under an inert atmosphere, such as nitrogen, by gradually increasing the temperature from 50° C. to 130° C. for a period of time sufficient to reduce the alcohol content from 3 moles to 1-1.5 moles per mole of MgCl
2
. The resulting partically dealcoholated adduct is in the form of spherical particles having an average diameter of 50 to 350 microns, a surface area, by B.E.T. using a Sorptomatic 1800 apparatus, of about 9 to 50 m
2
/g and a porosity, as determined with a mercury porosimeter, of 0.6 to 2 cc/g. For example, a MgCl
2
.3 ROH adduct, where R is a straight or branched C
2-10
alkyl, can be prepared according to the ingredients and procedure of example 2 of U.S. Pat. No. 4,399,054, the method of which is incorporated herein by reference, except that the stirring is done at 3,000 rpm instead of 10,000 rpm. The adduct particles thus formed are recovered by filtering, are washed 3 times at room temperature with 500 ml aliquots of anhydrous hexane and gradually heated by increasing the temperature from 50° C. to 130° C. under nitro
Basell Poliolefine Italia S.p.A.
Teskin Fred
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