Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2001-07-27
2003-08-19
Wilson, D. R. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S142000, C526S128000, C526S136000, C526S139000, C526S141000, C526S127000, C526S129000, C526S132000, C526S133000, C526S140000, C526S143000, C526S156000
Reexamination Certificate
active
06608152
ABSTRACT:
FIELD OF INVENTION
The present invention relates to a process for the polymerization of olefins having narrowed molecular weight distribution (MWD) values. Polyethylenes produced in accordance with the process of the present invention are generally characterized further by having a reduced n-hexane soluble polymeric fraction. Additionally, this invention relates to novel polyethylenes, and films and articles of manufacture produced therefrom.
BACKGROUND OF INVENTION
Catalyst systems for the polymerization of olefins are well known in the art and have been known at least since the issuance of U.S. Pat. No. 3,113,115. Thereafter, many patents have been issued relating to new or improved Ziegler-Natta type catalysts. Exemplary of such patents are U.S. Pat. Nos. 3,594,330; 3,676,415; 3,644,318; 3,917,575; 4,105,847; 4,148,754; 4,256,866; 4,298,713; 4,311,752; 4,363,904; 4,481,301 and Reissue No. 33,683.
These patents disclose Ziegler-Natta type catalysts that are well known as typically consisting of a transition metal component and a co-catalyst that is typically an organoaluminum compound. Optionally, used with the catalyst are activators such as halogenated hydrocarbons and activity modifiers such as electron donors.
The use of halogenated hydrocarbons with titanium-based Ziegler-Natta type polymerization catalysts in the production of polyethylene is disclosed in European Patent Applications EP A 0 529 977 A1 and EP 0 703 246 A1. As disclosed, the halogenated hydrocarbons may reduce the rate of ethane formation, improve catalyst efficiency, or provide other effects. Typical of such halogenated hydrocarbons are monohalogen and polyhalogen substitutes of saturated or unsaturated aliphatic, alicyclic, or aromatic hydrocarbons having 1 to 12 carbon atoms. Exemplary aliphatic compounds include methyl chloride, methyl bromide, methyl iodide, methylene chloride, methylene bromide, methylene iodide, chloroform, bromoform, iodoform, carbon tetrachloride, carbon tetrabromide, carbon tetraiodide, ethyl chloride, ethyl bromide, 1,2-dichloroethane, 1,2-dibromoethane, methylchloroform, perchloroethylene and the like. Exemplary alicyclic compounds include chlorocyclopropane, tetrachlorocyclopentane and the like. Exemplary aromatic compounds include chlorobenzene, hexabromobenzene, benzotrichloride and the like. These compounds may be used individually or as mixtures thereof.
It is also well known, in the polymerization of olefins, particularly where Ziegler-Natta type catalysts are employed, to utilize, optionally, electron donors. Such electron donors often aid in increasing the efficiency of the catalyst and/or in controlling the stereospecificity of the polymer when an olefin, other than ethylene, is polymerized. Electron donors, typically known as Lewis Bases, can be employed during the catalyst preparation step, referred to as internal electron donors, or during the polymerization reaction when the catalyst comes into contact with the olefin or olefins, referred to as external electron donors.
The use of electron donors in the field of propylene polymerization is well known and is primarily used to reduce the atactic form of the polymer and increase the production of the iosotactic polymers. However, while improving the production of isotactic polypropylene, electron donors tend, generally, to reduce the productivity of the Ziegler-Natta type catalyst.
In the field of ethylene polymerization, where ethylene constitutes at least about 50% by weight of the total monomers present in the polymer, electron donors are utilized to control the molecular weight distribution (MWD) of the polymer and the activity of the catalyst in the polymerization medium. Exemplary patents describing the use of internal electron donors in producing polyethylene are U.S. Pat. Nos. 3,917,575; 4,187,385, 4,256,866; 4,293,673; 4,296,223; Reissue No. 33,683; U.S. Pat. Nos. 4,302,565; 4,302,566; and 5,470,812. The use of an external electron donor to control molecular weight distribution is shown in U.S. Pat. No. 5,055,535; and the use of external electron donors to control the reactivity of catalyst particles is described in U.S. Pat. No. 5,410,002.
Illustrative examples of electron donors include carboxylic acids, carboxylic acid esters, alcohols, ethers, ketones, amines, amides, nitrites, aldehydes, alcoholates, thioethers, thioesters, carbonic esters, organosilicon compounds containing oxygen atoms, and phosphorus, arsenic or antimony compounds connected to an organic group through a carbon or oxygen atom.
The above is a partial listing of suitable electron donors. For the present invention, it is possible to use any electron donor that is suitable in a process for the polymerization of olefins.
SUMMARY OF THE INVENTION
The process of the present invention comprises polymerizing at least one olefin in the presence of both at least one Ziegler-Natta catalyst comprised of a component comprising at least one transition metal and a co-catalyst comprising at least one organometallic compound, and a sufficient amount of a specified compound to obtain an olefin homopolymer or interpolymer having a narrower molecular weight distribution than would be obtained in the absence of the specified compound. The specified compound added to the polymerization process is selected from the following:
1) An oxide of germanium, tin and lead;
2) Cyanogen (C
2
N
2
);
3) An oxide or imide of carbon of formula CE or C
3
E
2
where E=O and NR, R is hydrogen, a halogen, an alkyl group containing up to 50 non-hydrogen atoms, an aryl group containing up to 50 non-hydrogen atoms, a silyl group containing up to 50 non-hydrogen atoms, an alkoxy group containing up to 50 non-hydrogen atoms, an amino group containing up to 50 non-hydrogen atoms, a thiolato group containing up to 50 non-hydrogen atoms, or a boryl group containing up to 50 non-hydrogen atoms;
4) A sulfur, selenium, or tellurium containing chalcogenide of carbon, silicon, germanium, tin and lead;
5) A chalcogenide of carbon, silicon, germanium, tin and lead containing more than one chalcogen;
6) A chalcogenide imide of carbon, silicon, germanium, tin and lead having the formula C(E)(X) where E=O, S, Se, Te, or NR; X═NR′ where R and/or R′ is hydrogen, a halogen, an alkyl group containing up to 50 non-hydrogen atoms, an aryl group containing up to 50 non-hydrogen atoms, a silyl group containing up to 50 non-hydrogen atoms, or a boryl group containing up to 50 non-hydrogen atoms;
7) A chalcogenyl halide or imidohalide of carbon, silicon, germanium, tin and lead of the formula C(E)X
2
where E=O, S, Se, Te, and NR; R is hydrogen, a halogen, an alkyl group containing up to 50 non-hydrogen atoms, an aryl group containing up to 50 non-hydrogen atoms, a silyl group containing up to 50 non-hydrogen atoms, or a boryl group containing up to 50 non-hydrogen atoms; and X is a halogen;
8) An elemental form of phosphorus, arsenic, antimony and bismuth;
9) An oxide of nitrogen, phosphorus, arsenic, antimony and bismuth;
10) A nitrogen oxoacid or salt containing the anion thereof;
11) A halide of the formula E
n
X
m
, where E is nitrogen, phosphorus, arsenic, antimony or bismuth and X is a halogen or pseudohalogen, n=1 to 10, and m=1 to 20;
12) A chalcogenide or imide of nitrogen, phosphorus, arsenic, antimony and bismuth of the general formula E
n
Y
m
, where E=N, P, As, Sb, and Bi; Y═S, Se, Te, Po and NR; n=1 to 10; m=1 to 40; and R is hydrogen, a halogen, an alkyl group containing up to 50 non-hydrogen atoms, an aryl group containing up to 50 non-hydrogen atoms, a silyl group containing up to 50 non-hydrogen atoms, or a boryl group containing up to 50 non-hydrogen atoms;
13) A chalcogenyl or imido compound of nitrogen, phosphorus, arsenic, antimony and bismuth having the formula E
n
Y
m
X
q
, where E=N, P, As, Sb and Bi; Y═O, S, Se, Te and NR; X is hydrogen, a halogen, an alkyl group containing up to 50 non-hydrogen atoms, an aryl group containing up to 50 non-hydrogen atoms, a silyl group containing up to
Ford Randal Ray
Stuart, Jr. Richard Kingsley
Cheung William
Eastman Chemical Company
Graves, Jr. Bernard J.
Wilson D. R.
Wood Jonathan D.
LandOfFree
Process for the polymerization of olefins; novel... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the polymerization of olefins; novel..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the polymerization of olefins; novel... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3128493