Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2001-02-07
2004-03-09
Harlan, Robert Deshon (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S124300, C526S124500, C526S126000, C526S125300, C526S351000, C526S348000, C526S348600, C526S160000, C502S116000, C502S125000, C502S152000
Reexamination Certificate
active
06703455
ABSTRACT:
The invention relates to a process for the preparation of an olefin polymerization catalyst component comprising a magnesium dihalide, a titanium tetrahalide, and a dicarboxylic acid di-, oligo- or polyester as internal electron donor. The invention also relates to such a catalyst component and its use for the polymerization of &agr;-olefins such as propene.
BACKGROUND OF THE INVENTION
Generally, so called Ziegler-Natta catalyst components of the above kind have been prepared by reacting a magnesium halide-alcohol complex support with a titanium tetrahalide and an electron donor which usually is a phthalic acid di- oligo- or polyester. The preparation involves the use of large amounts of reagents and washing liquids, which are difficult to handle. Additionally, byproducts are formed, which cannot easily be regenerated or destroyed, but form an environmental problem.
For example, the preparation of a conventional polypropene catalyst component involves the reaction of a magnesium dichloride-alcohol complex support with titanium tetrachloride to give a surface layer of reactive &bgr;-magnesium dichloride as intermediate and hydrogen chloride and titanium alkoxy trichloride as byproducts. Then, the surface layer of reactive &bgr;-magnesium dichloride intermediate is activated with further titanium tetrachloride and optionally an internal electron donor to give said catalyst component (the treatment with a titanium halide such as titanium tetrachloride is henceforth called titanation). The result is an essentially inert magnesiumchloride based support covered with active sites based on titanium, chlorine and the optional internal electron donor.
The titanium alkoxy trichloride byproduct formed in such a titanation is a catalyst poison and must be carefully removed by extensive washing using large amounts of titanium tetrachloride. Further, the titanium alkoxy trichloride must be carefully separated from the titanium tetrachloride washing liquid, if the latter is to be reused e.g. for activating the reactive &bgr;-magnesium dichloride. Finally, the titanium alkoxy trichloride is a hazardous waste material, which is difficult to dispose of.
Thus, in a typical propene polymerization catalyst component preparation involving two titanations and three heptane washes, one mol of produced catalyst component (mol Mg) requires about 40 mol of titanium tetrachloride e.g. as washing liquid to be circulated, and produces as waste material an amount of about three mol of titanium alkoxy trichloride as well as about three mol of hydrogen chloride.
Sumitomo, EP 0 748 820 A1 (hereinafter referred to as “Sumitomo”), has prepared dialkoxy magnesium, reacted it with titanium tetrachloride to form an intermediate and then reacted the intermediate with phthalic acid dichloride to form a catalytically active propene polymerization catalyst component. The activity was raised by repeated titanations, as well as repeated washes with toluene and hexane. See page 10, lines 14 to 37, of said publication.
Said process of Sumitomo has avoided the reaction between the magnesium dichloride-alcohol complex and titanium tetrachloride, and thereby eliminated the formation of large amounts of catalytically poisonous titanium alkoxy trichloride byproduct. However, as much as four titanations and hydrocarbon treatments are still needed to give satisfactory catalytic activity.
DESCRIPTION OF THE INVENTION
The purpose of the present invention is to provide a process which results in a catalyst component having satisfactory activity without producing harmful byproducts such as said titanium alkoxy trichloride or requiring the use of large amounts of titanation reagent and/or washing liquid.
The problem described above has now been solved with a novel process for the preparation of a catalyst component of the above type, which is mainly characterized by the steps of:
(i) providing a magnesium compound (ab) containing an alkoxy moiety, selected from the group consisting of a magnesium dialkoxide, a complex containing a magnesium dihalide and an alcohol, and a complex containing a magnesium dihalide and a magnesium dialkoxide, and
(ii) reacting said magnesium compound (ab) with at least one dicarboxylic acid dihalide (c) which forms said dicarboxylic acid di-, oligo- or polyester as internal donor ED and has the formula (1):
wherein each R″ is a similar or different C
1
-C
20
hydrocarbyl group or both R″:s form together with the two unsaturated carbons of the formula a C
5
-C
20
aliphatic or aromatic ring, and X′ is a halogen, to give an intermediate (abc), and
(iii) reacting said intermediate (abc) with at least one titanium tetrahalide TiX″
4
(d) wherein X″ is a halogen,
(iv) recovering said catalyst component in crude form or recovering a precursor of said catalyst component, and
(v) optionally washing said crude catalyst component or said precursor, to give said catalyst component, and
by adding and reacting in connection with the e step (ii) or (iii) at least one halogenated hydrocarbon (e) of the formula (2)
R′″(X′″)
n
(2)
wherein R′″ is an n-valent C
1
-C
20
hydrocarbyl group, X′″ is a halogen and n is an integer selected from 1, 2, 3 and 4.
It has thus been found that a high activity olefin polymerization catalyst comprising a magnesium halide, a titanium tetrahalide and a dicarboxylic acid di-, oligo- or polyester as internal donor can be prepared without the above mentioned disadvantages by reacting a magnesium compound containing an alkoxy moiety with a dicarboxylic acid dihalide and a titanium tetrahalide and adding a reactive halogenated hydrocarbon.
Of the above mentioned steps (i) to (iii) preferably all are performed in solution. For dissolution of the reactants, one or several hydrocarbon solvents can be used, optionally together with the application of stirring and/or heating. Performing the process in a solution means that all reagent molecules can react with each other, thus forming a homogenous reaction product. Earlier processes which have been performed by reacting a solid support with a titanium compound and an electron donor, see above, do not form homogenous reaction products.
The catalyst component is in step (iv) preferably recovered in solid form by precipitation. Precipitation in the present invention means that the reaction product formed in solution is recovered as a powder, the particles of which consist of similar molecules of that reaction product. The particles formed according to the present invention are thus homogenous, while the particles of earlier processes are more or less heterogenous (inert core+active surface).
It is preferable if said first and second intermediates as well as the final product of the claimed process are separate compounds with an essentially stoichiometric composition. Often, they are complexes. A complex is, according to Rompps Chemie-Lexicon, 7. Edition, Franckh'sche Verlagshandlung, W. Keller & Co., Stuttgart, 1973, page 1831, “a derived name of compounds of higher order, which originate from the combination of molecules,—unlike compounds of first order, in the creation of which atoms participate.
Reactive halogenated hydrocarbons (e) of the present invention are, e.g., monochloromethane, dichloromethane, trichloromethane (chloroform), tetrachloromethane, monochloroethane, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1-chloropropane, 2-chloropropane, 1,2-dichloropropane, 1,3-dichloropropane, 1,2,3-trichloropropane, 1-chlorobutane, 2-chlorobutane, isobutyl chloride, tert.butyl chloride, 1,4-dichlorobutane, 1-chloropentane and 1,5-dichloropentane, as well as their corresponding compounds having other halogens. The chlorinated hydrocarbons of the invention may also be unsaturated, provided that the unsaturation does not act as catalyst poison in the final catalyst component.
In the invention, it was found that the addition of a
Ala-Huikku Sirpa
Garoff Thomas
Leinonen Timo
Harlan Robert Deshon
W. R. Grace & Co.-CONN
LandOfFree
Catalyst component comprising magnesium, titanium, a halogen... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Catalyst component comprising magnesium, titanium, a halogen..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catalyst component comprising magnesium, titanium, a halogen... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3225596