摘要:
Methods for preparing supported chromium catalysts containing a chromium (III) compound and an activator-support are disclosed. These supported chromium catalysts can be used in catalyst compositions for the polymerization of olefins to produce polymers having low levels of long chain branching, and with greater sensitivity to the presence of hydrogen during polymerization.
摘要:
Methods for preparing supported chromium catalysts containing a chromium (III) compound and an activator-support are disclosed. These supported chromium catalysts can be used in catalyst compositions for the polymerization of olefins to produce polymers having low levels of long chain branching, and with greater sensitivity to the presence of hydrogen during polymerization.
摘要:
Provided are a catalyst system for olefin oligomerization reaction and a method for olefin oligomerization, and more particularly, a catalyst system for olefin oligomerization reaction and a method for olefin oligomerization, which enable more efficient preparation of alpha-olefin, because a catalytic active ingredient is supported on a support, thereby exhibiting high activity in olefin oligomerization reaction even by using smaller amounts of a catalyst composition and a cocatalyst.
摘要:
The present invention provides a catalyst precursor, a catalyst system comprising the precursor, and a polymerization method using the catalyst system, an embodiment of the precursor is selected from the following structures: wherein T is a bridging group; M is selected from Groups 3 to 13 atoms, and the Lanthanide series of atoms the Periodic Table of the Elements; Z is a coordination ligand; each L is a monovalent, bivalent, or trivalent anionic ligand; X and Y are each independently selected from nitrogen, oxygen, sulfur, and phosphorus; each R can be the same or different and is a bulky substituent that is sterically hindering with respect to X and Y.
摘要:
The present invention provides a catalyst precursor and catalyst system comprising the precursor, an embodiment of the precursor is selected from the following structures: wherein T is a bridging group; M is selected from Groups 3 to 7 atoms; Z is a coordination ligand; each L is a monovalent, bivalent, or trivalent anionic ligand; X and Y are each independently selected from nitrogen, oxygen, sulfur, and phosphorus; R is a non-bulky substituent that has relatively low steric hindrance with respect to X; and R′ is a bulky substituent that is sterically hindering with respect to Y.
摘要:
This invention relates generally to low ethylene insertions into .alpha.-olefin polymers and processes for production of such polymers using unbridged fluxional metallocenes, primarily substituted aryl indenyl metallocenes, and more particularly to use of unbridged, fluxional, cyclopentadienyl or indenyl metallocene catalyst systems in methods of production of high melting point .alpha.-olefin homo- and co-polymers, particularly elastomeric crystalline and amorphous block homo- and co-polymers of .alpha.-olefins. The activity of fluxional unbridged metallocene polymerization catalysts containing at least one 2-arylindene ligand is increased 10.times. or more by the addition of small (typically 0.1-10 wt. %) amounts of ethylene to the polymerization system, which increase is termed the Polymerization Rate-Enhancement effect (PRE), which is measured in terms of an Ethylene Enhancement Factor (EEF) as a dimensionless ratio in the range of from about 1.1 to about 10 or above. A second important aspect of this invention is the ability to use a PRE activity-enhancing amount of ethylene in an olefin polymerization without substantially affecting the physical properties of the elastomer. In a third important aspect of this invention, .alpha.-olefin elastomers are produced through incorporation of ethylene using unbridged fluxional catalyst systems which may not otherwise produce acceptable elastomeric homopolymers. Preferred polymers of this invention retain sufficient crystallinity to provide a high melting point (by DSC) of about 80.degree. C., preferably above 100.degree. C., including in the range of from about 120.degree. C. to about 140.degree. C. and above. Novel flexible .alpha.-olefin homo and copolymers having elongation in excess of 600% and substantially no retained force are disclosed.
摘要:
Abstract of the Disclosure: Catalyst systems for the polymerization of C.sub.2 -C.sub.10 -alk-1-enes contain, as active components,a) a metallocene complex of the general formula I ##STR1## where M is titanium, zirconium, hafnium, vanadium, niobium or tantalum, X is halogen or C.sub.1 -C.sub.8 -alkyl, Y is carbon, phosphorus, sulfur, silicon or germanium, Z is C.sub.1 -C.sub.8 -alkyl, C.sub.3 -C.sub.10 -cycloalkyl or C.sub.6 -C.sub.10 -aryl, R.sup.1 and R.sup.2 are identical or different and are each C.sub.1 -C.sub.4 -alkyl, R.sup.3 to R.sup.6 are identical or different and are each hydrogen or C.sub.1 -C.sub.8 -alkyl, or two adjacent radicals R.sup.3 and R.sup.4 and R.sup.5 and R.sup.6 in each case together form a hydrocarbon ring system of 4 to 15 carbon atoms and n is 0, 1 or 2, andb) an open-chain or cyclic alumoxane compound of the general formula II or III ##STR2## where R.sup.7 is C.sub.1 -C.sub.4 -alkyl and n is from 5 to 30. The novel catalyst systems are particularly suitable for the preparation of polyalk-1-enes having high molecular weights.
摘要:
If a catalyst consisting of an aluminoxane and a metallocene of the formula I ##STR1## in particular R.sup.5 R.sup.6 C (Ind).sub.2 or R.sup.5 R.sup.6 C (Ind).sub.2 Zr(CH.sub.3).sub.2, is employed for the polymerization of olefins of the formulaR.sup.9 CH.dbd.CHR.sup.10(R.sup.9, R.sup.10 =H or C.sub.1 -C.sub.28 alkyl), the isotacticity of the polymer wax and hence the hardness and melting point can be varied simply by changing the polymerization temperature, without the molecular weight of the polymer being noticeably changed at the same time.
摘要:
Polymers of C.sub.2 -C.sub.12 -alk-1-enes are prepared at from -50 to 300.degree. C. and from 0.5 to 3000 bar in the presence of a catalyst system by a process in which the catalyst system used is one which containsA) an inorganic or organic carrier,B) a metallocene complex,C) a compound forming metallocenium ions andD) if required, a metal compound of the general formula IM.sup.1 (R.sup.1).sub.r (R.sup.2).sub.s (R.sup.3).sub.t I whereM.sup.1 is an alkali metal, an alkaline earth metal or a metal of main group III of the Periodic Table,R.sup.1 is hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl or arylalkyl, each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical,R.sup.2 and R.sup.3 are each hydrogen, halogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl, arylalkyl or alkoxy, each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical,r is an integer from 1 to 3 ands and t are integers from 0 to 2, the sum r+s+t corresponding to the valency of M.sup.1,and in which an antistatic agent is used.
摘要:
A process for producing a propylene polymer having an intrinsic viscosity (.eta.), as measured in decahydronaphthalene at 135.degree. C., of 1 to 12 dl/g comprises polymerizing propylene optionally with other olefins in the presence of an olefin polymerization catalyst comprising a transition metal compound represented by the formula ##STR1## wherein R.sup.1 and R.sup.2 are each a hydrogen atom or a hydrocarbon group of 1 to 3 carbon atoms,X.sup.1 and X.sup.2 are each a halogen atom, andY is a divalent silicon-containing group.