摘要:
Latency information is used for coding of additional information in a record medium. This additional information which gets embossed in the record medium might be used for verification purposes in that only storage media with the correct latency information are judged to be authentic or might be decoded in a proper way. This technique is applicable to record media, recordable record media, an emulator for recordable or non-recordable record media, a method for producing recordable or non-recordable record media, a method for verifying recordable or non-recordable record media, a record medium writing device for producing recordable or non-recordable record media, and a record medium accessing device for verifying recordable or non-recordable record media.
摘要:
A beam catcher (1) for a light beam (2) pulsating in amplitude at a modulation frequency (f) with a photodetector (4) with a plurality of photosensors (6) which are offset in a spatially defined manner relative to a reference point (5), an evaluating circuit (7), and an output device (8). A phase shifter (10) that is sensitive to the modulation frequency (f) is arranged between at least two photosensors (6).
摘要:
The invention relates to a method of obtaining a copy protected optical record carrier carrying information in different blocks, a method of accessing such a copy protected optical record carrier and such an optical record carrier itself. Access devices for optical carriers return different results when retrieving blocks, which contain incorrect address data in the corresponding subcode fields. A copy protection key will be implemented during manufacture of an optical record carrier by modifying the subcode address information of a predetermined pattern of blocks. It is normally not possible to copy incorrect address data onto an optical record carrier, since the address data will be newly generated during the copy process. Therefore, such a key can be utilized to distinguish between an original disc and a copied or non original disc. The key is preset before manufacturing of the optical record carrier itself and can therefore be used to encrypt the data stored on the optical record carrier. Upon accessing of the data, first the key is extracted from the optical record carrier and then the data can be decrypted utilizing this key.
摘要:
A very effective catalyst system for the polymerization or copolymerization of olefins comprises a cocatalyst, preferably an aluminoxane or a supported aluminoxane, and a metallocene of the formula I in which, in the preferred form, M1 is Zr or Hf, R1 and R2 are halogen or alkyl, R3 is alkyl, R4 to R12 are alkyl or hydrogen and R13 is a (substituted) alkylene or heteroatom bridge. The metallocenes, in particular the zirconocenes, produce polymers of very high molecular weight, in the case of prochiral monomers polymers of very high molecular weight, very high stereotacticity and very high melting point, at high catalyst activities in the industrially interesting temperature range between 50 and 80° C.
摘要:
A highly effective catalyst system for the polymerization of olefins comprises a cocatalyst, preferably an aluminoxane, and a metallocene of the formula I ##STR1## where M.sup.1 =Zr or Hf, R.sup.1 and R.sup.2 =(C.sub.1 -C.sub.3)-alkyl or chlorine, R.sup.3, with the proviso that at least one of the radicals R.sup.3 is not hydrogen, is hydrogen, F, Cl, --OR.sup.7, --NR.sup.7 R.sup.8, --P(O)R.sup.7 R.sup.8, --P(OR.sup.7).sub.2 or SR.sup.7, R.sup.4 is a ##STR2## radical, and m plus n are zero or 1.
摘要:
In the case of Ziegler catalysts based on a metallocene as the transition metal component and an aluminoxane as the activator, preactivation of the metallocene with the aluminoxane results in a considerable increase in the activity of the catalyst system. Furthermore, 1-olefin polymers of a high degree of isotacticity and having compact, spherical particles, a very narrow particle size distribution and a high bulk density are obtained by means of a catalyst system of this type.
摘要:
A composite film is described which has at least one base layer which predominantly comprises polypropylene, and at least one top layer. The top layer is sealable and comprises a homopolymer of an olefin. A process for producing the composite film, the top layer olefin homopolymer and packaging material made from the film also are described.
摘要:
The present invention relates to a metallocene compound of the formula I R.sup.5.sub.n Cp.sup.1 Cp.sup.2 M.sup.1 R.sup.1 R.sup.2 (I) where Cp.sup.1 and Cp.sup.2 are, independently of one another, identical or different and are each an unsubstituted or substituted cyclopentadienyl group, n=zero or 1, R.sup.5 is a bridge, M.sup.1 is a metal of group IVb, Vb or VIb of the Periodic Table of the Elements, R.sup.1 and R.sup.2 are identical or different and are each a hydrogen atom or a C.sub.1 -C.sub.40 -group, wherein at least one of the two groups Cp.sup.1 and Cp.sup.2 is a substituted cyclopentadienyl group which bears at least one cyclic C.sub.3 -C.sub.30 -group containing at least one heteroatom in the ring, or which bears a fused-on C.sub.2 -C.sub.30 ring system containing at least one heteroatom in the ring. The metallocene compound can be used as a catalyst component for olefin polymerization.
摘要:
The present invention relates to a metallocene compound of the formula I ##STR1## which can advantageously be used as catalyst component for olefin polymerization.
摘要:
Polyolefins with a molecular weight distribution M.sub.w /M.sub.n .gtoreq.3.0, which may be monomodal, bimodal or multimodal, can be obtained by polymerization or copolymerization of olefins with a catalyst system consisting of an aluminoxane and a transition metal component (metallocene), in which the transition metal component consists of at least one zirconocene of the formula I and at least one zirconocene of the formula Ia ##STR1## or alternatively of at least 2 zirconocenes of the formula I.