Patents by Inventor Akhtar Osman

Akhtar Osman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5397851
    Abstract: A process for producing high cis-1,4-polybutadienes wherein there is reduced gel formation is provided which process comprises: polymerizing 1,3-butadiene in a polymerization medium comprising an inert hydrocarbon solvent and water at a temperature of from about -30.degree. C. to about 60.degree. C. in the presence of a catalyst system which is a mixture of (1) a substantially anhydrous divalent cobalt salt, (2) diethyl aluminum chloride or ethyl aluminum sesquichloride and (3) an organo aluminum compound of the formula R.sub.3 Al wherein R is an alkyl group having from 8 to 12 carbon atoms and, optionally triethylaluminum, the molar ratio of chloride in the diethyl aluminum chloride plus (3) being from about 0.7:1 to about 1 and the molar ratio of chloride in the ethyl aluminum sesquichloride plus (3) being from about 0.7:1 to about 1.
    Type: Grant
    Filed: November 9, 1993
    Date of Patent: March 14, 1995
    Assignee: Polysar Rubber Corporation
    Inventors: Thomas F. Knauf, Akhtar Osman
  • Patent number: 5362817
    Abstract: A process for preparing linear block and three arm star block copolymers having blocks of polyisobutylene and blocks of anionically polymerizable monomers comprises mixing a first solution of a polyisobutylene having a number average molecular weight of from about 4,000 to about 60,000 and having from 1 to 3 terminal allylic halogens with a second solution of a living alkali metal terminated polymer having a number average molecular weight of from about 4,000 to about 60,000 in relative proportions at a temperature of from about 10.degree. C. to about 80.degree. C. for a period of time of from about 30 minutes to about 24 hours whereby a significant amount of linear block or three arm star block copolymer is formed. A polyisobutylene having from 1 to 3 terminal allylic halogens is provided and a process for preparing said polyisobutylene.
    Type: Grant
    Filed: August 18, 1993
    Date of Patent: November 8, 1994
    Assignee: Polysar Rubber Corporation
    Inventor: Akhtar Osman
  • Patent number: 5342908
    Abstract: A halogenated polymer analogous to halogenated butyl rubber is prepared by a process wherein a monomer charge comprising isobutylene, and a conjugated diolefin having the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 which may be the same or different are a methyl group or a hydrogen atom and X is bromine or chlorine together with a initiator having the formula ##STR2## wherein each R.sub.4 may be the same or different is a alkyl, aryl or aralkyl group of 1 to 8 carbon atoms and n is a positive whole number are introduced into a suitable reaction vessel in a specified ratio at a temperature of from about -90.degree. to -10.degree.C., a solution of a Lewis acid is added and the monomers are copolymerized at said temperature to form said halogenated polymer, and the halogenated polymer is recovered from solution.
    Type: Grant
    Filed: February 5, 1993
    Date of Patent: August 30, 1994
    Assignee: Polysar Rubber Corporation
    Inventor: Akhtar Osman
  • Patent number: 5260383
    Abstract: A process for preparing linear block and three arm star block copolymers having blocks of polyisobutylene and blocks of anionically polymerizable monomers comprises mixing a first solution of a polyisobutylene having a number average molecular weight of from about 4,000 to about 60,000 and having from 1 to 3 terminal allylic halogens with a second solution of a living alkali metal terminated polymer having a number average molecular weight of from about 4,000 to about 60,000 in relative proportions at a temperature of from about 10.degree. C. to about 80.degree. C. for a period of time of from about 30 minutes to about 24 hours whereby a significant amount of linear block or three arm star block copolymer is formed. A polyisobutylene having from 1 to 3 terminal allylic halogens is provided and a process for preparing said polyisobutylene.
    Type: Grant
    Filed: April 17, 1991
    Date of Patent: November 9, 1993
    Assignee: Polysar Rubber Corporation
    Inventor: Akhtar Osman
  • Patent number: 5244965
    Abstract: The present invention provides a process to remove phosphine residues from a hydrogenated polymer solution.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: September 14, 1993
    Assignee: Polysar Limited
    Inventors: Akhtar Osman, William G. Bradford
  • Patent number: 4944926
    Abstract: The present invention provides a method to treat a rhodium containing solution which is derived from the catalytic hydrogenation of nitrile rubber.An additive selected from thiourea, polysaccharide and carbon black is used to cause a rhodium-containing precipitate. The precipitate is then separated from the solution by, for example, filtration or centrifugation.
    Type: Grant
    Filed: August 1, 1988
    Date of Patent: July 31, 1990
    Assignee: Polysar Limited
    Inventors: Akhtar Osman, William G. Bradford
  • Patent number: 4943616
    Abstract: A polymerization process is provided for producing a terminally functional polymer which comprises introducing a monomer charge, a Lewis acid and an organic peroxy compound into a suitable reaction vessel and polymerizing the monomer charge at a temperature of from about 0.degree. to about -80.degree. C. to form the terminally functional polymer, wherein the monomer charge comprises isobutylene and the organic peroxy compound is charged in an amount of from about 10.sup.-4 to about 10.sup.-1 moles per mole of the isobutylene. In a preferred embodiment, the monomer charge additionally comprises vinylidene aromatic or diolefin monomers. In another preferred embodiment the monomer charge comprises the sequential addition of isobutylene and vinylidene aromatic or diolefin monomers. In a further preferred embodiment said reaction vessel is additionally charged with an electron door having an electron door number of from about 22 to about 50 the amount of said electron door being from about 10.sup.-4 to about 10.
    Type: Grant
    Filed: December 4, 1989
    Date of Patent: July 24, 1990
    Assignee: Polysar Limited
    Inventors: Munmaya K. Mishra, Akhtar Osman
  • Patent number: 4908421
    Abstract: A polymerization process is provided for producing a terminally functional polymer which comprises introducing a monomer charge, a Lewis acid and an organic peroxy compound into a suitable reaction vessel and polymerizing the monomer charge at a temperature of from about 0.degree. to about -80.degree. C. to form the terminally functional polymer, wherein the monomer charge comprises isobutylene and the organic peroxy compound is charge in an amount of from about 10.sup.-4 to about 10.sup.-1 moles per mole of the isobutylene. In a preferred embodiment, the monomer charge additionally comprises vinylidene aromatic or diolefin monomers. The invention also provides a novel catalyst system comprising an organic peroxy compound and a Lewis acid for the polymerization of isobutylene or monomer mixtures containing isobutylene.
    Type: Grant
    Filed: July 26, 1988
    Date of Patent: March 13, 1990
    Assignee: Polysar Limited
    Inventors: Munmaya K. Mishra, Akhtar Osman