Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...
Reexamination Certificate
1999-07-21
2002-04-23
Wood, Elizabeth (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Plural component system comprising a - group i to iv metal...
C502S113000, C502S115000
Reexamination Certificate
active
06376416
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an olefin polymerization catalyst and to an olefin polymer production process. More specifically, the invention relates to a catalyst and process for production of olefin polymers with excellent moldability, using a solid catalyst component comprising a combination of a specifically treated clay compound and a metallocene compound.
2. Background Art
In recent years, metallocene catalysts with excellent polymerizing properties that give olefin polymers with a narrow composition distribution have been developed. Such catalysts, however, have generally had a drawback of poor moldability of products due to a very narrow molecular weight distribution thereof.
Olefin polymerization processes aimed at improving moldability have therefore been proposed. As examples there may be mentioned a process of combining a plurality of metallocene compounds with different extension reaction rate constants and termination reaction rate constants (Japanese Patent Laid-Open Publication No. 60-35008), a process of using a metallocene compound having a ligand with a special constrained geometric structure (Japanese Patent Laid-Open Publication No. 3-163008), and processes of combining metallocene-type catalysts and Ziegler-type catalysts using alumoxanes as an activator (Japanese Patent Laid-Open Publication No. 63-501369, Japanese Patent Laid-Open Publication No. 1-503715 and Japanese Patent Laid-Open Publication No. 3-203903). However, while such methods do provide some improving effects, their effects are still inadequate so that further improvement is desired.
On the other hand, because methylalumoxane used with metallocene catalysts is very expensive, olefin polymerization processes have been proposed that use no methylalumoxane. For example, there is known a process using a clay compound (Japanese Patent Laid-Open Publication No.5-301917). There have also been disclosed processes of combining a metallocene compound with a non-metallocene transition metal compound, for the purpose of improved moldability (Japanese Patent Laid-Open Publication No. 6-136046 and No. 9-132613). To the knowledge of the present inventors, however, all of these processes still provide inadequate effects of improved moldability.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an olefin polymerization catalyst and process which allow production of olefin polymers with excellent moldability, and exhibiting excellent activity.
The present invention offers a solution to the aforementioned problems by using a specific solid catalyst component comprising a combination of a specifically treated clay compound and a metallocene compound.
That is, the olefin polymerization catalyst according to the present invention is characterized by comprising the following component (A) and component (B);
component (A): a solid catalyst component comprising the following component (A-1) and component (A-2).
component (A-1): a solid component obtained by contacting the following component (A-1-1), component (A-1-2) and component (A-1-3).
component (A-1-1): an ion-exchangeable layered silicate
component (A-1-2): a magnesium compound
component (A-1-3): a titanium compound
component (A-2): a metallocene-type transition metal compound
component (B): an organic aluminum compound.
The olefin polymer production process according to the present invention is characterized by contacting an olefin with the aforementioned olefin polymerization catalyst for its polymerization.
According to the invention, there are provided polymers with excellent moldability due to a wider molecular weight distribution (i.e. a larger ratio Mw/Mn between weight-average molecular weight (Mw) and number-average molecular weight (Mn) (Q value)) and a larger FR and melt tension (MT), compared to olefin polymers produced by polymerizing olefins in the presence of catalysts using conventional metallocene-type transition metal compounds.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[Olefin Polymerization Catalyst]
The olefin polymerization catalyst according to the present invention comprises component (A) and component (B). Here, “comprises” means not only combinations of the indicated component (A) and component (B) alone, but also encompasses combinations of adjuvant components other than component (A) component (B) but for the same purpose, that are added to component (A) and component (B).
<Component (A)/solid Catalyst Component>
Component (A) is a solid catalyst component comprising the following component (A-1) and component (A-2). Here as well, “comprises” not only means combinations of the indicated component (A-1) and component (A-2) but also encompasses combinations thereof with adjuvant components for the same purpose.
<<Component (A-1)>>
Component (A-1) is a solid component obtained by contacting the following component (A-1-1), component (A-1-2) and component (A-1-3), or if necessary a solid component obtained by further contacting component (A-1-4) therewith.
The term “containing” as used herein is intended to mean not only that components (A-1-1), (A-1-2), (A-1-3) and, if desired, (A-1-4) are brought into contact with each other, but also that component (A-1-2) obtained by contacting an inorganic magnesium compound with a titanium compound such as (A-1-3) is brought into contact with component (A-1-1) and component (A-1-4) to obtain component (A).
Component (A-1-1)
Component (A-1-1) is an ion-exchangeable layered silicate.
The ion-exchangeable layered silicate used for the invention is a silicate compound having a crystalline structure wherein planes constructed by ion-bonding, etc. are stacked together in parallel by weak bonding, the ions contained in which are exchangeable. Ion-exchangeable layered silicates are for the most part produced naturally as the major components of primarily clay minerals, but these ion-exchangeable layered silicates are not particularly limited to natural products and may be artificially synthesized substances.
As specific examples of ion-exchangeable layered silicates there may be mentioned the following publicly known layered silicates listed in “Clay Mineralogy” by Haruo Shiramizu, Asakura Shoten Publications (1995) and elsewhere: (a) the kaolin group, for example dickite, nacrite, kaolinite, anoxite, metahalloysite, halloysite, etc., (b) the serpentine group, for example, chrysotile, lizardite, antigorite, etc., (c) the smectite group, for example montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, etc., (d) the vermiculite group, for example vermiculite, etc., (e) the mica group, for example mica, illite, cerisite, glauconite, etc., and (f) others, for example attapulgite, sepiolite, palygorskite, bentonite, pyroferrite, talc, chlorite, etc. These may be used to form mixed layers as well. Preferred among these are smectites such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite and stevensite, bentonite and teniolite, vermiculites such as vermiculite, and micas such as mica, illite, cerisite and glauconite.
The ion-exchangeable layered silicate preferably has a volume of 0.1 cc/g or greater, and especially 0.3-5 cc/g, of pores with a radius of at least 20 Angstroms as measured by the mercury injection method.
The ion-exchangeable layered silicate can be used directly without any particularly special treatment, but it may be subjected to chemical treatment for removal of impurities adhering to the surface, for increase of the surface area, for control of the interlayer distance or for conversion of the crystal structure of the clay. Specifically there may be mentioned acid treatment, alkali treatment, salt treatment, organic substance treatment, etc. Acid treatment and salt treatment are preferred.
For salt treatment, at least 40% and preferably at least 60% of the exchangeable metal cations contained in the ion-exchangeable layered silicate prior to treatment are preferably ion-exchanged with dissociated cations of the salt.
Hirakawa Katsumi
Uehara Yumito
Japan Polychem Corporation
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Pasterczyk J.
Wood Elizabeth
LandOfFree
Olefin polymerization catalyst and process for producing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Olefin polymerization catalyst and process for producing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Olefin polymerization catalyst and process for producing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2883418