Patents by Inventor Syamalarao Evani

Syamalarao Evani 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: 5159035
    Abstract: Ionic copolymers exhibiting uniform, gel-free solution viscosity and a controllable melt viscosity and hot melt tension are prepared by copolymerizing in an oil phase a nonionic monomer such as styrene or an alkylacrylate with an ionic monomer such as zinc dodecyl maleate or didodecyldimethylammonium p-styrene sulfonate.
    Type: Grant
    Filed: May 9, 1988
    Date of Patent: October 27, 1992
    Assignee: The Dow Chemical Company
    Inventor: Syamalarao Evani
  • Patent number: 4994352
    Abstract: An article and method for its perparation is disclosed wherein the article comprises a substrate having at least one planar surface on which is disposed a thermally decomposable metallo-organic compound in active association with a photosensitive dye. The article can be easily processed with, for example, a source of energy such as a laser beam to encode information or produce electroconductive lines.
    Type: Grant
    Filed: January 29, 1990
    Date of Patent: February 19, 1991
    Assignee: The Dow Chemical Company
    Inventors: Andrew J. G. Strandjord, Michael S. Paquette, Syamalarao Evani, Ronald L. Yates, Mark D. Newsham
  • Patent number: 4933405
    Abstract: Ionic copolymers exhibiting uniform, gel-free solution viscosity aned a controllable melt viscosity and hot melt tension are prepared by copolymerizing in an oil phase a nonionic monomer such as styrene or an alkylacrylate with an ionic monomer such as zinc dodecyl maleate or didodecyldimethylammonium p-styrene sulfonate.
    Type: Grant
    Filed: June 10, 1986
    Date of Patent: June 12, 1990
    Assignee: The Dow Chemical Company
    Inventor: Syamalarao Evani
  • Patent number: 4921902
    Abstract: A hydrophobe associative composition of an ethylenically unsaturated, water-soluble monomer such as acrylamide and an ethylenically unsaturated amphiphilic monomer such as dodecyl poly(oxyethylene).sub.10 methacrylate which is particularly effective for increasing the viscosity of brines or other aqueous media contaning salts or other electrolytes. Such copolymers are therefor useful in mobility control fluids and fracturing fluids for enhanced oil recovery and as drag reduction agents.
    Type: Grant
    Filed: February 2, 1984
    Date of Patent: May 1, 1990
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, K. Van Phung
  • Patent number: 4814096
    Abstract: An aqueous liquid medium having increased low shear viscosity and utility as a mobility control agent in enhanced oil recovery is provided by dispersing into the aqueous medium (1) a hydrophilic/hydrophobic polymer having hydrophobic groups, e.g., an acrylamide/dodecyl methacrylate copolymer, and (2) a water-dispersible surfactant, e.g., dodecyl polyethyleneoxy glycol monoether.
    Type: Grant
    Filed: August 1, 1983
    Date of Patent: March 21, 1989
    Assignee: The Dow Chemical Company
    Inventor: Syamalarao Evani
  • Patent number: 4728696
    Abstract: The invention comprises a composition comprising at least one compound defined by the formula ##STR1## wherein R is hydrogen, C.sub.1-4 alkyl or a group ##STR2## wherein G is a divalent hydrocarbyl-linking group and J, D, E and F are hereinafter defined; wherein J and E independently are divalent linking groups selected from ##STR3## wherein R' is hydrogen or C.sub.1-4 alkyl; D is a divalent hydrocarbyl group which lends hydrophobicity to the compound; and F is a monovalent hydrocarbyl group which lends hydrophilicity to the compound. Such compositions are useful as comonomers with water-soluble monomers such as acrylamide and acrylic acid which form water-dispersible thickening agents which are resistant to shear degradation and heat and have a broad range of salt tolerance. Aqueous solutions thickened with such copolymers are useful in enhanced oil recovery processes as fluid mobility control agents, as fracturing fluids and drilling muds as well as hydraulic fluids and lubricants in many applications.
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: March 1, 1988
    Assignee: The Dow Chemical Company
    Inventors: Kien Van Phung, Syamalarao Evani
  • Patent number: 4702854
    Abstract: Substantially oil-free aqueous industrial fluids possess superior lubricating and wear preventing characteristics and are useful as hydraulic fluids and metalworking compositions. Fluids of the invention comprise (1) an aqueous liquid and (2) a water-soluble synthetic addition copolymer of a poly-2-oxazoline or a poly-2-oxazine.The industrial fluids exhibit good Newtonian behavior and mechanical stability at high shear.
    Type: Grant
    Filed: May 2, 1983
    Date of Patent: October 27, 1987
    Assignee: The Dow Chemical Company
    Inventors: Kenneth L. Snyder, Jr., Syamalarao Evani
  • Patent number: 4535098
    Abstract: Water absorbent compositions comprise a water swellable polymer which contains polymerized water-soluble monomers, water-insoluble monomers having a pendant hydrophobic moiety, and optionally, a crosslinking monomer. The polymer can be blended with a colloidal support such as colloidal silica. The compositions exhibit good water absorbency rates and high gel strengths.
    Type: Grant
    Filed: March 12, 1984
    Date of Patent: August 13, 1985
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, James H. Oswald, Thomas L. Staples, Brent T. Polak
  • Patent number: 4505827
    Abstract: The rheology of aqueous liquids is effectively controlled by the addition to the liquid of a water-dispersible BAB triblock polymer wherein the B blocks are hydrophobic blocks such as alkyl or sulfonated poly(t-butylstyrene) and the A block is a hydrophilic block such as sulfonated poly(vinyltoluene).
    Type: Grant
    Filed: September 19, 1983
    Date of Patent: March 19, 1985
    Assignee: The Dow Chemical Company
    Inventors: Gene D. Rose, Kent S. Dennis, Syamalarao Evani
  • Patent number: 4432881
    Abstract: An aqueous liquid medium having increased low shear viscosity as provided by dispersing into the aqueous medium (1) a water-soluble polymer having pendant hydrophobic groups, e.g., an acrylamide dodecyl acrylate copolymer, and (2) a water-dispersible surfactant, e.g., sodium oleate, or dodecyl polyethyleneoxy glycol monoether. The thickened aqueous medium is suitably emloyed in applications requiring viscous liquids which retain their viscosity when subjected to shear, heat or high electrolyte (salt) concentrations. Such applications include uses in enhanced oil recovery processes, as fluid mobility control agents, fracturing fluids and drilling muds, as well as hydraulic fluids and lubricants in many applications.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: February 21, 1984
    Assignee: The Dow Chemical Company
    Inventor: Syamalarao Evani
  • Patent number: 4242408
    Abstract: A non-woven flexible web having enhanced wet strength and easy disposability is prepared by adhering the fibrous elements of the web with a polymer of an unsaturated acid and an unsaturated water-insoluble monomer in a ratio wherein the polymer is insoluble at lower pH values and soluble at higher pH values.
    Type: Grant
    Filed: June 25, 1979
    Date of Patent: December 30, 1980
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, William A. Foster
  • Patent number: 4200720
    Abstract: Low molecular weight polymers of an unsaturated dicarboxylic anhydride monomer (e.g., maleic anhydride) and a copolymerizable monomer (e.g., styrene) are prepared by an improved process which comprises polymerizing the monomers in the presence of the hydroxide or a nucleophilic salt of a monovalent cation (e.g., a nucleophilic salt or the hydroxide of the ammonium cation, a quaternary ammonium compound, a protonated primary, secondary or tertiary amine, a sulfonium compound, a phosphonium compound or an alkali metal cation). By the practice of this process, low molecular weight polymers are conveniently and economically obtained without the use of high catalyst concentrations, high temperatures, conventional chain transfer agents, high boiling chain transfer solvents or combinations thereof.
    Type: Grant
    Filed: August 24, 1978
    Date of Patent: April 29, 1980
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, Russell J. Raymond
  • Patent number: 4198269
    Abstract: Properties of fibrous materials, e.g., wet and dry strength of paper, are significantly improved by incorporating a cationic polyether into a fibrous material such as pulp. The polyether bears ammonium salt groups exemplified by the formula: ##STR1## wherein R.sub.1 and R.sub.2 are individually hydrogen, hydrocarbyl such as alkyl, hydroxyhydrocarbyl, or hydrocarbylamino; E is individually ##STR2## or E and R.sub.1 are collectively ##STR3## wherein R is hydrogen or alkyl, R.sub.3 is hydroxyl, halogen, hydrogen or hydrocarbyl, R.sub.4 is hydrogen or hydrocarbyl; and A.sup..crclbar. is an anion of an ammonium salt. Such polyethers also function as retention aids for sizing agents and dyes and as antistatic agents.
    Type: Grant
    Filed: March 9, 1979
    Date of Patent: April 15, 1980
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, George R. Killat
  • Patent number: 4180637
    Abstract: Low molecular weight polymers of an unsaturated dicarboxylic anhydride monomer (e.g., maleic anhydride) and a copolymerizable monomer (e.g., styrene) are prepared by an improved process which comprises polymerizing the monomers in the presence of the hydroxide or a nucleophilic salt of a monovalent cation (e.g., a nucleophilic salt or the hydroxide of an ammonium compound or of an alkali metal). By the practice of this process, low molecular weight polymers are conveniently and economically obtained without the use of high catalyst concentrations, high temperatures, conventional chain transfer agents, high boiling chain transfer solvents or combinations thereof.
    Type: Grant
    Filed: November 7, 1977
    Date of Patent: December 25, 1979
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, Russell J. Raymond
  • Patent number: 4156775
    Abstract: Properties of fibrous materials, e.g., wet and dry strength of paper, are significantly improved by incorporating a cationic polyether into a fibrous material such as pulp. The polyether bears ammonium salt groups exemplified by the formula: ##STR1## wherein R.sub.1 and R.sub.2 are individually hydrogen, hydrocarbyl such as alkyl, hydroxyhydrocarbyl, or hydrocarbylamino; E is individually ##STR2## or E and R.sub.1 are collectively ##STR3## wherein R is hydrogen or alkyl, R.sub.3 is hydroxyl, halogen, hydrogen or hydrocarbyl, R.sub.4 is hydrogen or hydrocarbyl; and A.sup..crclbar. is an anion of an ammonium salt. Such polyethers also function as retention aids for sizing agents and dyes and as antistatic agents.
    Type: Grant
    Filed: January 26, 1976
    Date of Patent: May 29, 1979
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, George R. Killat
  • Patent number: 4151341
    Abstract: Novel low molecular weight interpolymers containing pendant lower alkyl capped poly(oxyethylene)ether groups are effective as aqueous dispersing agents for particulate matter and are particularly effective for difficult-to-disperse, finely divided inorganic solids such as precipitated calcium carbonate and satin white. The interpolymers comprise, in polymerized form, (1) an alkenyl benzyl ether of an ethoxylated lower alkane compound, which ether has the formula: ##STR1## (wherein R is hydrogen or methyl, R.sub.1 is lower alkyl and m is a positive integer greater than 1) with (2) a copolymerizable ethylenically unsaturated acid such as acrylic acid, methacrylic acid, etc., or a copolymerizable ethylenically unsaturated dicarboxylic anhydride such as maleic anhydride and (3) a hydrophobic monomer such as styrene.
    Type: Grant
    Filed: April 5, 1978
    Date of Patent: April 24, 1979
    Assignee: The Dow Chemical Company
    Inventors: Robert H. Lalk, Syamalarao Evani
  • Patent number: 4148945
    Abstract: The thermoplastic polymer employed in this invention is a rubber modified unsaturated carboxylic acid or anhydride containing polymer which is prepared by polymerizing the monomers in the presence of the rubber in a finely divided form. The surface to be metallized is first aminated with aqueous hydroxylamine or hydrazine, then treated with a noble metal salt solution and thereafter treated with a reducing agent, as needed, to produce a metallized surface having a resistance of 100 ohms/sq. or less. The metallized surface can then be further plated by conventional means.
    Type: Grant
    Filed: February 4, 1974
    Date of Patent: April 10, 1979
    Assignee: The Dow Chemical Company
    Inventors: Leigh B. Bangs, Carole K. Tuttle, Syamalarao Evani
  • Patent number: 4105649
    Abstract: A novel polymer of a vinyl benzyl ether monomer and at least one other copolymerizable monomer, at least one of which other monomers has a carboxylic acid group, an anhydride group, a sulfate group, a sulfonate group or a hydroxyl group is disclosed. The vinyl benzyl ether monomer has the formula ##STR1## wherein R is hydrogen or methyl, m is about 10 to 100 and Y is --OR.sub.1, --SR.sub.1, ##STR2## where R.sub.1 is an alkyl, aralkyl or alkaryl hydrophobic group of 10 to about 22 carbon atoms, R.sub.2 is an alkyl group of 1 to about 22 carbon atoms and R.sub.3 is hydrogen or an alkyl group of 1 to about 22 carbon atoms, provided R.sub.2 and R.sub.3 in combination have at least 10 carbon atoms.
    Type: Grant
    Filed: October 7, 1974
    Date of Patent: August 8, 1978
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, Frederick P. Corson
  • Patent number: 4038265
    Abstract: Nonionic water soluble thickening agents are prepared by copolymerizing about 1 to 5 mole percent of a vinyl benzyl ether having the formula ##STR1## and the balance to make 100 mole percent of acrylamide.
    Type: Grant
    Filed: October 28, 1975
    Date of Patent: July 26, 1977
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, Frederick P. Corson
  • Patent number: 4029872
    Abstract: Nonionic water soluble thickening agents are prepared by copolymerizing about 1 to 5 mole percent of a vinyl benzyl ether having the formula ##STR1## and the balance to make 100 mole percent of acrylamide.
    Type: Grant
    Filed: October 28, 1975
    Date of Patent: June 14, 1977
    Assignee: The Dow Chemical Company
    Inventors: Syamalarao Evani, Frederick P. Corson