Olefin polymerization using a catalyst comprising a group VIIIB

Details Olefin polymerization using a catalyst comprising a group VIIIB Olefin polymerization using a catalyst comprising a group VIIIB

1997-11-06

1999-11-16

Wu, David W.

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Polymers from only ethylenic monomers or processes of...

526135, 526145, 526147, 526172, 502155, C08F 406

Patent

active

059860278

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to polymers obtainable by polymerization of olefinically unsaturated monomers in the presence of a catalyst system which comprises as active constituents and Lewis acids, the Elements, units of elements of groups IVA, VA and VIA of the Periodic Table of the Elements, C.sub.1 -C.sub.20 -organic and C.sub.3 -C.sub.30 -organosilicon radicals, where the radicals may contain one or more elements of groups IVA, VA, VIA and VIIA of the Periodic Table of the Elements.
In addition, the invention relates to a process for preparing these polymers, to films, fibers and moldings produced from these polymers and to the use of the polymers of the present invention as films, fibers and moldings.
The polymerization of olefinic monomers, for example ethylene, C.sub.3 -C.sub.8 -alk-1-enes and acrylic acid derivatives is well known for different polymerization processes, and the polyolefins which can be obtained are widely used commercially in many application areas, for example as film, moldings and fibers.
The polymerization of the olefins is catalyzed or initiated, inter alia, by means of mixed catalysts comprising compounds of the early transition metals (titanium, zirconium, etc) and alkyl compounds of the main group metals (eg. aluminum alkyls), known as Ziegler catalysts, or else by means of free-radical initiators.
However, Ziegler catalysts have a number of disadvantages. They generally react, sometimes very vigorously, with moisture and oxygen, which generally results in loss of their catalytic activity.
Furthermore, these catalysts are generally not able to (co)polymerize unsaturated compounds which contain functional groups such as carboxyl groups or ester groups.
In addition, the polymerization of cyclic, olefinically unsaturated monomers or of multiply olefinically unsaturated, linear monomers often does not proceed in the desired way, namely as a polyinsertion reaction, but secondary reactions such as ring opening of the cyclic monomers or ring formation from the linear monomers occur. The resulting polymers have a relatively high nonuniformity of the chemical composition and also of the molecular weight distribution.
Free-radical initiators are, generally under high pressure, able to copolymerize, for example, olefins with polar, unsaturated monomers, but the incorporation of the comonomers is often nonuniform and the polymer chains generally have nonuniform branching, which leads, for example, to a low polymer film quality.
These characteristics restrict the range of applications of the resulting polymers which are obtained by the various known polymerization processes and it is therefore desirable to seek alternative polymers which do not have the disadvantages mentioned or have them only to a subordinate degree.
EP-A 0 589 527 describes catalyst systems based on specific palladium-phosphine complexes for homopolymerization and copolymerization of olefins. However, both the preparative accessibility and also the polymerization behavior of these catalysts leave something to be desired. Thus, only low degrees of polymerization (oligomers having from 3 to 20 monomer units) are obtained in polar solvents such as methanol, ethylene glycol or water. In nonpolar solvents such as diethylene glycol dimethyl ether (diglyme), maximum molar masses M.sub.n of 5600 are achieved, but only traces of the comonomer are then incorporated. Furthermore, the use of internal olefins is not described and the double bond content of the polymers and their molecular weight distribution M.sub.w /M.sub.n is likewise not disclosed.
EP-A 0 454 231 describes catalyst systems based on cationic metal complexes of late transition metals (group VIII) for the polymerization of ethylene, olefins and alkynes. However, these catalysts are very sensitive to impurities. Likewise, the is achievable productivities leave something to be desired. No polar copolymers are described.
It is an object of the present invention to provide novel polymers which do not have the disadvantages indicated and which, in particular, compri

REFERENCES:
patent: 5216120 (1993-06-01), Drent et al.

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