Patents by Inventor Balaram Gupta

Balaram Gupta 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: 5731401
    Abstract: A new process is provided for the formation of aromatic polyesters directly from the reaction of dialkyl ester of an aromatic carboxylic acid with dihydric phenols. The polycondensation is carried out in the presence of (a) a condensing agent; (b) a catalyst selected from the group consisting of derivatives of Group I metals, derivatives of Group IV A metals, derivatives of Group IV B metals, and mixtures thereof; and (c) a co-catalyst selected from the group consisting of methanesulfonic acid, sulfuric acid, p-toluenesulfonic acid, alkanoic acid having the formula, C.sub.n H.sub.x F.sub.y COOH, where n is an integer from 1 to 4, x and y are integers from 0 to 2n+1, and the sum of x and y is 2n+1, and mixtures thereof; at suitable temperature and pressure conditions and for a sufficient period of time to form the aromatic polyester.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: March 24, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, Matthew J. Bylicki
  • Patent number: 5393848
    Abstract: An improved liquid crystalline polymer blend is produced by mixing a preformed thermotropic liquid crystalline polymer in the melt phase with reactants needed to form a second liquid crystalline polymer under conditions sufficient to form the second liquid crystalline polymer. The resulting blends are anisotropic and have improved morphology and improved melt processability. The method is particularly useful when the second liquid crystalline polymer is biphasic or is difficult to synthesize or process in the melt.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: February 28, 1995
    Assignee: Hoechst Celanese Corp.
    Inventors: Larry F. Charbonneau, Balaram Gupta, H. Clay Linstid, Linda C. Sawyer, James P. Shepherd
  • Patent number: 5306800
    Abstract: Pseudo network polymer is characterized by a network of linear segments which is composed of recurring units of a multivalent branching moiety, a chain-defining moiety, and a coupling moiety. The polymer may be formed into film, fiber and molded articles which exhibit improved mechanical properties in the transverse direction.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: April 26, 1994
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, Larry F. Charbonneau, Wilfried Hatke
  • Patent number: 5143947
    Abstract: Radiation curable compositions useful as coatings for wood, metal, glass, fabric, paper, fiber and plastics are made from copolymers of 4-hydroxystyrene and an alkadiene or an allyl ester of an ethylenically unsaturated acid blended wit ethylenically unsaturated compounds.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: September 1, 1992
    Assignee: Hoechst Celanese Corporation
    Inventor: Balaram Gupta
  • Patent number: 5140093
    Abstract: Novel thermotropic polyesters and polyester-amides containing fluorine bearing linking groups are disclosed and claimed. Preferred embodiments include thermotropic polymers prepared from 4-Hydroxybenzoic acid, 6-hydroxy-2 naphthoic acid, 2,2-bis(4-carboxyphenyl)hexafluoropropane, hydroquinone, and terephthalic acid.
    Type: Grant
    Filed: July 15, 1991
    Date of Patent: August 18, 1992
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, Larry F. Charbonneau, Gordon W. Calundann, Tai-Shung Chung
  • Patent number: 5120793
    Abstract: Ether derivatives of polymers of p-hydroxystyrene are made by reacting the polymer through Michael addition with an ethylenically unsaturated compound which contains an electron withdrawing group on the carbon atom alpha to the unsaturation.
    Type: Grant
    Filed: April 18, 1990
    Date of Patent: June 9, 1992
    Assignee: Hoechst Celanese Corp.
    Inventor: Balaram Gupta
  • Patent number: 5109101
    Abstract: Thermoplastic polyarylate compositions suitable for molding are formed from isophthalic acid, terephthalic acid or mixtures thereof, a bisphenolic compound such as bisphenol A and from about 5 to 10 mole % relative to the monomeric charge of 2-hydroxy-6-naphthoic acid.
    Type: Grant
    Filed: January 23, 1991
    Date of Patent: April 28, 1992
    Assignee: Hoechst Celanse Corp.
    Inventors: Balaram Gupta, Gordon W. Calundann
  • Patent number: 5023314
    Abstract: Thermoplastic polyarylate compositions suitable for molding are formed from isophthalic acid, terephthalic acid or mixtures thereof, a bisphenolic compound such as bisphenol A and from about 5 to 10 mole % relative to the monomeric charge of 2-hydroxy-6-naphthoic acid.
    Type: Grant
    Filed: November 7, 1989
    Date of Patent: June 11, 1991
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, Gordon W. Calundann
  • Patent number: 5004762
    Abstract: Radiation curable compositions useful as coatings for wood, metal, glass, fabric, paper, fiber and plastics are made from homopolymers of 4-acetoxystyrene or homopolymers of 4-hydroxystyrene blended with ethylenically unsaturated compounds.
    Type: Grant
    Filed: November 22, 1989
    Date of Patent: April 2, 1991
    Assignee: Hoechst Celanese Corp.
    Inventor: Balaram Gupta
  • Patent number: 5001215
    Abstract: A process is described for producing shapable aromatic polyesters derived from 1,3-bis(p-carboxyphenoxy)propane (CPP) and a dihydric phenol comprising forming a mixed anhydride of CPP with a lower monocarboxylic acid containing at least 2 carbon atoms, e.g., acetic acid, and subsequently polymerizing said mixed anhydride with said dihydric phenol or a reactable diester of said dihydric phenol, to obtain said aromatic polyester. The process is capable of producing aromatic polyesters as described having a glass transition temperature of at least about 70.degree. C.
    Type: Grant
    Filed: November 2, 1989
    Date of Patent: March 19, 1991
    Assignee: Hoechst Celanese Corp.
    Inventor: Balaram Gupta
  • Patent number: 4997892
    Abstract: A sulfoalkyl derivative of N-substituted hydroxyethylated polybenzimidazole is disclosed, produced by the reaction of an N-substituted hydroxyethylated polybenzimidazole anion with a sultone. The N-substituted hydroxyethylated polybenzimidazole polymer is first reacted with an alkali hydride to produce the anion of N-substituted hydroxyethylated polybenzimidazole. The N-substituted hydroxyethylated polybenzimidazole anion is then reacted with the sultone to produce a sulfoalkyl derivative of the N-substituted hydroxyethylated polybenzimidazole polymer. These derivatives find great use as ion exchange devices.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: March 5, 1991
    Assignee: Hoechst Celanese Corp.
    Inventors: Michael J. Sansone, Balaram Gupta, Charles E. Forbes, Mark S. Kwiatek
  • Patent number: 4942026
    Abstract: Sodipotassic copper tube silicate species of the family Na.sub.2--2x K.sub.2x CuSi.sub.4 O.sub.10 are synthesized by combining, with an organo silicate at essentially room temperature, stoichiometric amounts of a copper salt, and at least one salt of potassium and sodium, in an aqueous alcohol solution to form a gel. The gel is then sintered at elevated temperature and for a time sufficient to form a crystalline specie of Na.sub.2--2x K.sub.2x CuSi.sub.4 O.sub.10.
    Type: Grant
    Filed: May 10, 1989
    Date of Patent: July 17, 1990
    Assignee: Hoechst Celanese Corporation
    Inventors: Balaram Gupta, Cheng K. Saw, Malcolm E. Kenny, Bruce A. Harrington
  • Patent number: 4937319
    Abstract: A process is described for producing shapable aromatic polyesters derived from bisphenol A and a dicarboxylic acid comprising isophthalic acid, terephthalic acid, or a mixture of the two, comprising forming a mixed anhydride of said dicarboxylic acid and acetic acid, and subsequently reacting said mixed anhydride with bisphenol A while drawing off acetic acid by-product to obtain said aromatic polyester.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: June 26, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, John R. Costanza
  • Patent number: 4929537
    Abstract: Negative photoresist compositions are made from copolymers of 4-hydroxystyrene and dialkyl muconates, alkyl sorbates, alkadiene monomers or allyl esters of ethylenically unsaturated acids plus a photosensitizer. Such compositions are useful in photolithographic and photomasking operations in fabricating microelectronic devices, printed circuits, semiconductors, printing plates, dies and the like.
    Type: Grant
    Filed: July 27, 1989
    Date of Patent: May 29, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, Palaiyur S. Kalyanaraman
  • Patent number: 4877843
    Abstract: Copolymers of p-acetoxystyrene and allyl esters of ethylenically unsaturated acids are selectively hydrolyzed to copolymers of p-vinylphenol and allyl esters of ethylenically unsaturated acids using acid or base catalysis in an alcohol or water.
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: October 31, 1989
    Assignee: Hoechst Celanese Corporation
    Inventor: Balaram Gupta
  • Patent number: 4869994
    Abstract: Negative photoresist compositions are made from copolymers of 4-hydroxystyrene and dialkyl muconates, alkyl sorbates, alkadiene monomers or allyl esters of ethylenically unsaturated acids plus a photosensitizer.Such compositions are useful in photolithographic and photomasking operations in fabricating microelectronic devices, printed circuits, semiconductors, printing plates, dies and the like.
    Type: Grant
    Filed: January 25, 1988
    Date of Patent: September 26, 1989
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, Palaiyur Kalyanaraman
  • Patent number: 4868274
    Abstract: There are provided novel homopolyanhydrides of carboxyaryloxyalkanoic acids, e.g. p-carboxyphenoxyacetic acid or 6-(p-carboxyphenoxy)hexanoic acid, capable of being formed into shaped articles. The homopolyanhydrides may be prepared by heating under reflux a solution of the acid monomer in acetic anhydride to form a mixed anhydride of the acid monomer and acetic acid and melt polycondensing the prepolymer by heating it under vacuum in an inert atmosphere. Due to their property of hydrolytic cleavage at predictable rates, the homopolyanhydrides are suitable as polymer matrices providing for the controlled release of an agent such as a drug.
    Type: Grant
    Filed: May 23, 1988
    Date of Patent: September 19, 1989
    Assignee: Hoechst Celanese Corp.
    Inventors: Balaram Gupta, Gordon W. Calundann
  • Patent number: 4868265
    Abstract: A process is provided for preparing homopolyanhydrides or regularly alternating copolyanhydrides by condensing a bis(trimethylsilyl) ester of a dicarboxylic acid, e.g., an alkylenedicarboxylic acid such as sebacic acid or a bis(p-carboxyphenoxy)alkane such as 1,3-bis(p-carboxyphenoxy)propane, with a dicarboxylic acid chloride, e.g., an alkylenedicarboxylic acid chloride such as sebacoyl chloride or a phenylenedicarboxylic acid chloride such as terephthaloyl chloride or isophthaloyl chloride, to yield the polyanhydride and chlorotrimethylsilane as a by-product. The process may be carried out in the presence of a condensation catalyst, e.g., a highly ionized organic or inorganic fluoride, such as tetrabutylammonium fluoride.
    Type: Grant
    Filed: October 5, 1988
    Date of Patent: September 19, 1989
    Assignee: Hoechst Celanese Corp.
    Inventor: Balaram Gupta
  • Patent number: 4857601
    Abstract: Copolymers of p-acetoxystyrene and dialkyl muconates or alkyl sorbates are selectively hydrolyzed to copolymers of p-vinylphenol and dialkyl muconates or alkyl sorbates using acid or base catalysis in an alcohol or water.
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: August 15, 1989
    Assignee: Hoechst Celanese Corp.
    Inventor: Balaram Gupta
  • Patent number: 4826891
    Abstract: Radiation curable compositions useful as coatings for wood, metal, glass, fabric paper, fiber and plastics are made from copolymers of p-acetoxystyrene and another monomer which is an alkadiene or an allyl ester of a polymerizable ethylenically unsaturated acid blended with ethylenically unsaturated compounds.
    Type: Grant
    Filed: June 8, 1987
    Date of Patent: May 2, 1989
    Assignee: Hoechst Celanese Corporation
    Inventor: Balaram Gupta