Patents by Inventor Mohammed Tazi

Mohammed Tazi 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: 5003014
    Abstract: What is described herein is a process for making copolymers of maleic anhydride and C.sub.1 -C.sub.4 alkyl vinyl ethers of predetermined specific viscosities extending over a wide viscosity range. The invention is characterized by (a) precharging a reactor with a C.sub.1 -C.sub.4 alkyl vinyl ether as solvent and a polymerization initiator at a reaction temperature, (b) feeding a mixture of maleic anhydride and a C.sub.1 -C.sub.4 alkyl vinyl ether in substantially stoichiometric amounts, preferably with a slight excess of alkyl ether, and at a selected rate, into said precharged reactor, (c) polymerizing said reactants to form a slurry of said copolymer in said escess alkyl vinyl ether solvent, and (d) introducing toluene into said reactor during the polymerization to control the specific viscosity of the copolymer product being produced.
    Type: Grant
    Filed: May 21, 1990
    Date of Patent: March 26, 1991
    Assignee: GAF Chemicals Corporation
    Inventors: Mohammed Tazi, John J. Ardan
  • Patent number: 4992517
    Abstract: What is described herein is a process for making copolymers of maleic anhydride and a C.sub.1 -C.sub.8 alkyl vinyl ether. In this process, a reactor is precharged with a solution of maleic anhydride in a sterically hindered monoether solvent and the alkyl vinyl ether monomer is fed thereto. Copolymerization is effected in the presence of a free radical initiator. A pumpable slurry of the copolymer in the reaction medium is formed upon polymerization, from which a copolymer product which is substantially a benzene-free powder is obtained.
    Type: Grant
    Filed: April 19, 1989
    Date of Patent: February 12, 1991
    Assignee: GAF Chemicals Corporation
    Inventors: Mohammed Tazi, Harold J. Harwood
  • Patent number: 4962185
    Abstract: Substantially benzene-free copolymers of maleic anhydride and alkyl vinyl ethers having benzene present in an amount of less than 1 ppm and toluene present in an amount of about 2.0 wt. % or less are provided by treating the copolymer powder with toluene at a temperature of about 115.degree. C. to about 125.degree. C.
    Type: Grant
    Filed: October 2, 1989
    Date of Patent: October 9, 1990
    Assignee: GAF Chemicals Corporation
    Inventors: Mohammed Tazi, Yoon T. Kwak, Krystyna Plochocka
  • Patent number: 4956430
    Abstract: The invention relates to the production of high molecular weight vinyl lactam-quaternized amino acrylamide copolymers having less than 0.1% residual unreacted monomer, which comprises: subjecting the monomers to solution polymerization in the presence of a buffering agent having chelating properties for complexing with traces of heavy metals; controlling the pH of the polymerization to a level above 5.5 while continuously ebulating nitrogen gas through the system during reaction and incrementally adding a free radical initiator in 2 to 4 stages during the conversion to copolymer. The invention also relates to the substantially pure vinyl lactam-acrylamide copolymer having a Brookfield viscosity of at least 75,000 cps. and a residual monomer content below 0.5 wt. %, for example less than 1,000 ppm.
    Type: Grant
    Filed: May 1, 1989
    Date of Patent: September 11, 1990
    Assignee: GAF Chemicals Corporation
    Inventor: Mohammed Tazi
  • Patent number: 4954336
    Abstract: Non-aerosol pump hair spray compositions herein are applied as a fine spray mist, without nozzle clogging, and dried rapidly, to provide superior hair holding power. The compositions includes a hair fixative resin which is a copolymer of maleic anhydride and an alkyl vinyl ether, and the ethyl and butyl half-esters thereof, in an amount of between 6 and 20% solids. In suitable embodiments of the invention, the resin is the C.sub.2 -C.sub.4 alkyl half-ester of maleic anhydride and C.sub.1 -C.sub.5 alkyl vinyl ether having a relative viscosity of about 1.20 to 1.35 (1% in ethanol).
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: September 4, 1990
    Assignee: GAF Chemicals Corporation
    Inventors: Jui-Chang Chuang, Edward Walls, Jr., Stephen C. Johnson, Mohammed Tazi
  • Patent number: 4948848
    Abstract: What is described herein is a solution feed, slurry precipitation polymerization process for making copolymers of maleic anhydride and an alkyl vinyl ether within a predetermined viscosity range.The process of the invention is characterized by precharging a large excess of the alkyl vinyl ether in a reactor, feeding maleic anhydride dissolved in a minimum amount of an organic solvent into the precharged reactor, and polymerizing the monomers in the presence of a free radical initiator. The copolymer product then appears as a pumpable slurry in the reaction medium. The slurry is discharged from the reactor and the desired copolymer is obtained therefrom as a fine, white powder having specific viscosities in the range of about 1.5-6.0, and preferably about 2.6-3.5.
    Type: Grant
    Filed: April 7, 1989
    Date of Patent: August 14, 1990
    Assignee: GAF Chemicals Corporation
    Inventors: Mohammed Tazi, Nikhil Kundel
  • Patent number: 4939198
    Abstract: A solution feed, solution polymerization method for making copolymers of maleic anhydride and an alkyl vinyl ether is described. In this process, maleic anhydride in a functional organic solvent is fed into a reactor precharged with an alkyl vinyl ether. The reactant solution is polymerized in the presence of a free radical initiator to provide copolymers in solution having low viscosities and high solids content.
    Type: Grant
    Filed: April 7, 1989
    Date of Patent: July 3, 1990
    Assignee: GAF Chemicals Corporation
    Inventors: Mohammed Tazi, Nikhil Kundel
  • Patent number: 4900809
    Abstract: Substantially benzene-free copolymers of maleic anhydride and alkyl vinyl ethers having benzene present in an amount of less than about 1 ppm and an alkyl-substituted aromatic hydrocarbon present in an amount of about 2.0 wt. % or less, and a process for rendering a copolymer reaction product of maleic anhydride and an alkyl vinyl ether prepared in benzene solution substantially benzene-free, is described herein.
    Type: Grant
    Filed: March 13, 1989
    Date of Patent: February 13, 1990
    Assignee: GAF Chemicals Corporation
    Inventors: Mohammed Tazi, Robert B. Login, Nikhil Kundel