摘要:
The novel metallocenes of the formula I ##STR1## in which, preferably, M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 and R.sup.4 are hydrogen, R.sup.5 and R.sup.6 are alkyl or haloalkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n -- is a single- or multi-membered chain in which R.sup.7 may also be a (substituted) hetero atom, m+n is zero or 1, and R.sup.10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high stereospecificity and high melting point.
摘要:
A polypropylene molding composition having syndiotactic polymer chains is obtained in a high yield by the copolymerization of propylene with ethylene or a 1-olefin of the formula R.sup.a --CH.dbd.CH--R.sup.b in the presence of a catalyst comprising a metallocene of the formula I ##STR1## in which M.sup.1 is titanium, zirconium, hafnium, vanadium, riobium or tantalum, and an aluminoxane. This molding composition has a very high molecular weight, a very narrow molecular-weight distribution and very high syndiotaxy. Shaped articles produced from the molding composition are distinguished by high transparency, flexibility, bear strength and excellent surface luster.
摘要:
Olefins of the formulaR.sup.11 --CH.dbd.CH--R.sup.12(R.sup.11 and R.sup.12 =H or C.sub.1 -C.sub.14 -alkyl) are polymerized in the presence of a catalyst comprising at least one metallocene of the formula I ##STR1## (M=zirconium or hafnium) and an aluminoxane, giving polymers of high molecular weight in high yield.
摘要:
1-Olefin polymer waxes having a very narrow molecular weight distribution, high isotacticity, a narrow grain size distribution and a high bulk density are obtained by means of a catalyst comprising a chiral, stereorigid metallocene compound and an aluminoxane, in the presence of small amounts of hydrogen during the polymerization.
摘要:
Improved Ziegler-Natta catalysts and methods of making the improved catalyst are described. The Ziegler-Natta catalyst is formed using a spherical MgCl2-xROH support, where R is a linear, cyclic or branched hydrocarbon unit with 1-10 carbon atoms and where ROH is an alcohol or a mixture of at least two different alcohols and where x has a range of about 1.5 to 6.0, preferably about 2.5 to 4, more preferably about 2.9 to 3.4, and even more preferably 2.95 to 3.35. The Ziegler-Natta catalyst includes a Group 4-8 transition metal and an internal donor comprising a diether compound. The catalyst has improved activity in olefin polymerization reactions as well as good stereoregularity and hydrogen sensitivity, and may be useful in the production of phthalate-free propylene polymers having a molecular weight distribution (PI(GPC)) in the range from about 5.75 to about 9.
摘要:
A method for copy protection in which an audiovisual or audio data is divided into a plurality of portions. The plurality of portions is at least partly scrambled and prepared so as to be stored on a record carrier in the scrambled order. This is done so that a physical position on the record carrier, e.g., a sector of the record carrier, where a respective portions of the divided data is stored depends on the scrambled order.
摘要:
Methods and compositions are provided for the identification of a molecular diagnostic test for cancer. The test identifies cancer subtypes that are responsive to anti-angiogenesis therapeutics and enables classification of a patient within this subtype. The present invention can be used to determine whether patients with cancer are clinically responsive or non-responsive to a therapeutic regimen prior to administration of any anti-angiogenic agent. This test may be used in different cancer types and with different drugs that directly or indirectly affect angiogenesis or angiogenesis signalling. In addition, the present invention may be used as a prognostic indicator for certain cancer types. In particular, the present invention is directed to the use of certain combinations of predictive markers, wherein the expression of the predictive markers correlates with responsiveness or non-responsiveness to a therapeutic regimen.
摘要:
A rotating laser device and method is disclosed. The laser device includes a laser unit, which generates a laser beam, a leveling device, which aligns the laser beam in a horizontal plane which is arranged perpendicular to the gravitational field of the earth, an inclination device, which inclines the laser beam about an axis of inclination in relation to the horizontal plane, a rotational unit which moves the laser unit at least partially about an axis of rotation at a rotational speed, and a measuring unit with which an angle of rotation of the laser unit about the axis of rotation can be determined such that a memory unit is provided for storing at least one angular position.
摘要:
A laser receiver (1) for acoustically indicating a laser beam, including a housing (4), a detector unit (6) that ascertains the actual position (2) of the laser beam, an evaluation unit (8) that determines the difference between the actual position (2) and the target position (3), and an acoustic indication device (7) that uses an acoustic signal to indicate whether the actual position (2) of the laser beam is above, below or at the target position (3), wherein a control unit (9) is provided that, as a function of the difference between the actual position (2) and the target position (3), generates a scanning signal to modulate a basic signal, and then sends the scanning signal to the acoustic indication device (7).
摘要:
Certain metallocene compounds are provided that, when used as a component in a supported polymerization catalyst under industrially relevant polymerization conditions, afford high molar mass homo polymers or copolymers like polypropylene or propylene/ethylene copolymers without the need for any α-branched substituent in either of the two available 2-positions of the indenyl ligands. The substituent in the 2-position of one indenyl ligand can be any radical comprising hydrogen, methyl, or any other C2-C40 hydrocarbon which is not branched in the α-position, and the substituent in the 2-position of the other indenyl ligand can be any C4-C40 hydrocarbon radical with the proviso that this hydrocarbon radical is branched in the β-position. This metallocene topology affords high melting point, very high molar mass homo polypropylene and very high molar mass propylene-based copolymers. The activity/productivity levels of catalysts including the metallocenes of the present invention are exceptionally high.