Patents Examined by Perfirio Nazario-Gonzalez
  • Process for the preparation of an olefin polymer
    Patent number: 5329033
    Abstract: A very effective catalyst system for olefin polymerization consists of a cocatalyst, preferably an aluminoxane, and a metallocene of the formula (I) ##STR1## in which, preferably, M.sup.1 is Zr, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 to R.sup.6 are alkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n -- is a chain having one or more members, in which R.sup.7 can also be a (substituted) hetero atom, and m+n is zero or 1. The catalyst system leads to polymers of variable molecular weight and stereotacticity, depending on the substituents R.sup.3 to R.sup.6 chosen, at polymerization temperatures which are relevant in industry.
    Type: Grant
    Filed: October 25, 1993
    Date of Patent: July 12, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Spaleck, Jurgen Rohrmann, Martin Antberg
  • Process of optically resoluting optically active platinum complex compound
    Patent number: 5298642
    Abstract: Disclosed herein is a process of optically resoluting optically active platinum complex compounds which comprises optically resoluting a d-isomer and an 1-isomer of a cis-Pt(II) complex of a 1,2-cyclohexanediamine isomer characterized in that the mixture of the d-isomer and the 1-isomer is optically resoluted by means of high performance liquid chromatography employing a column packed with a chiral filler.The chiral filler include, for example, a cellulose ester derivative, a cellulose carbamate derivative, an amylose carbamate derivative, a polymethacryl acid ester and .beta.- and .gamma.-cyclodextrin.According to the present invention, the optical resolution of a platinum complex compound essentially consisting of the mixture of two optical isomers which cannot be resoluted in accordance with a normal resolution method due to the small structural difference can be easily performed utilizing the characteristics of a chiral filler.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: March 29, 1994
    Assignee: Tanaka Kikinzoku Kogyo K.K.
    Inventors: Takeshi Tozawa, Yasunobu Komoda, Junji Ohnishi, Yukie Masuda, Junichi Taniuchi, Chihiro Nakanishi, Koji Okamoto
  • 1,2,3,4-tetraalkyl-5-perfluoroalkyl-cyclopentadiene, di-(perfluoroalkyl)-trialkylcyclopentadiene and transition metal complexes thereof
    Patent number: 5245064
    Abstract: The present invention provides a compound of the formula: ##STR1## wherein R.sup.1 is (C.sub.1 -C.sub.5)perfluoroalkyl, R.sup.2 is (C.sub.1 -C.sub.5)perfluoroalkyl or (C.sub.1 -C.sub.5)alkyl, R.sup.3 is (C.sub.1 -C.sub.5)perfluoroalkyl or (C.sub.1 -C.sub.5)alkyl, R.sup.4 is (C.sub.1 -C.sub.5)alkyl and R.sup.5 is (C.sub.1 -C.sub.5)alkyl, with the proviso that no more than two of R.sup.1, R.sup.2 and R.sup.3 can be (C.sub.1 -C.sub.5)perfluoroalkyl; and transition metal complexes thereof.
    Type: Grant
    Filed: August 14, 1992
    Date of Patent: September 14, 1993
    Inventors: Paul G. Gassman, John R. Sowa, John W. Mickelson