Patents Assigned to SRCHEM Incorporated
  • Patent number: 5391642
    Abstract: Higher molecular weight copolymers of polyaspartic acid which are suitable for the inhibition of scale deposition may be obtained by reacting maleic acid and ammonia in a stoichiometric excess, with a diamine or a triamine, at 120.degree.-350.degree. C., preferably 180.degree.-300.degree. C., and then converting the copolymer of polysuccinimlde formed to a salt of a copolymer of polyaspartic acid by hydrolysis with a hydroxide.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: February 21, 1995
    Assignee: SRCHEM Incorporated
    Inventor: Louis L. Wood
  • Patent number: 5389303
    Abstract: Polyamino acids or their salts mixed with citric acid or its salts, in a ratio of 75:25 to 0.1:99.9, polyamino acid or its salt to citric acid or its salts, and especially in a ratio of 1:1 to 1:99 polyamino acids or their salts to citric acid or its salts, provide a much higher rate of chelation of calcium ion than expected on the basis of the addition of the polyamino acid to citric acid. Such mixtures may be used in high volume water applications such as boiler, cooling, oil well, agricultural sprays and irrigation water. They are also useful in preventing scale formation on fabrics when formulated with laundry detergents and in preventing scale formation on glassware when formulated in dishwashing detergents.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: February 14, 1995
    Assignee: SRCHEM Incorporated
    Inventors: Louis L. Wood, Gary J. Calton
  • Patent number: 5367047
    Abstract: Polyaspartate, useful for inhibition of incrustations due to materials causing hardness in water and of value in detergent formulations, can be prepared by reacting maleic acid or fumaric acid in a molar ratio of 1:1-2.1 at temperatures greater than 190.degree. C., followed by conversion of the polymer formed in this reaction to a salt of polyaspartic acid by basic hydrolysis.
    Type: Grant
    Filed: February 22, 1994
    Date of Patent: November 22, 1994
    Assignee: Srchem Incorporated
    Inventor: Louis L. Wood
  • Patent number: 5357004
    Abstract: Higher molecular weight copolymers of polyaspartic acid which are suitable for the inhibition of scale deposition may be obtained by reacting maleic acid and ammonia in a stoichiometric excess, with a diamine or a triamine, at 120.degree.-350.degree. C., preferably 180.degree.-300.degree. C., and then converting the copolymer of polysuccinimide formed to a salt of a copolymer of polyaspartic acid by hydrolysis with a hydroxide. Alkyl or substituted alkyl groups may be incorporated in the backbone of the polymer by adding a alkyl or substituted alkyl monoamine to maleic acid and ammonia and heating at 120.degree. C. or more until polymerization has occurred.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: October 18, 1994
    Assignee: Srchem Incorporated
    Inventors: Gary J. Calton, Louis L. Wood
  • Patent number: 5306429
    Abstract: Copolymers of polyamino acids formed by reaction of polysuccinimide with alkyl, alkenyl, aromatic amines or alkyl and alkenyl polyamines are useful as inhibitors of mineral scale deposition. Such compounds may be used in high volume water applications such as boiler, cooling, oil well, agricultural sprays and irrigation water. They are also useful in preventing scale formation on fabrics when formulated with laundry detergents and in preventing scale formation on glassware when formulated in dishwashing detergents.
    Type: Grant
    Filed: October 29, 1992
    Date of Patent: April 26, 1994
    Assignee: Srchem, Incorporated
    Inventors: Louis L. Wood, Gary J. Calton
  • Patent number: 5292864
    Abstract: Solutions of polymers of aspartic acid or its amine copolymers prepared by thermal condensation are reacted with a decolorizing agent selected from the group consisting of hypochlorfte, chlorine, chlorine dioxide, hydrogen peroxide, a peroxycarboxylate or ozone, sufficient in strength to effect the desired decolorization.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: March 8, 1994
    Assignee: SRCHEM Incorporated
    Inventors: Louis L. Wood, Gary J. Calton
  • Patent number: 5292858
    Abstract: Copolymers of polyamino acids formed by reaction of an alcohol with maleic anhydride to form the half ester followed by addition of ammonia, ammonia and an amine, or ammonia and a polyamine. The mixture is then heated to 120.degree.-350.degree. C. to form polysuccinimide or a derivative thereof. The resulting polysuccinimide may be hydrolyzed to form a derivative of polyaspartic acid or its salt.
    Type: Grant
    Filed: March 16, 1993
    Date of Patent: March 8, 1994
    Assignee: SRCHEM Incorporated
    Inventor: Louis L. Wood
  • Patent number: 5288503
    Abstract: An oral pharmaceutical composition comprising a hydrophobic resin or ion exchange resin which has a therapeutic agent bound thereto forming an agent-resin complex is disclosed. The complex is coated with a water-permeable diffusion barrier of poly(vinyl alcohol) polymer cryogel.
    Type: Grant
    Filed: June 16, 1992
    Date of Patent: February 22, 1994
    Assignee: SRCHEM Incorporated
    Inventors: Louis L. Wood, Gary J. Calton
  • Patent number: 5288783
    Abstract: Polyaspartate, useful or inhibition of incrustations due to materials causing hardness in water and of value in detergent formulations, can be prepared by reacting maleic acid or fumaric acid in a molar ratio of 1:1-2.1 at temperatures greater than 170.degree. C., followed by conversion of the polymer formed in this reaction to a salt of polyaspartic acid by basic hydrolysis.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: February 22, 1994
    Assignee: Srchem Incorporated
    Inventor: Louis L. Wood
  • Patent number: 5286810
    Abstract: Higher molecular weight copolymers of polyaspartic acid which are suitable for the inhibition of scale deposition may be obtained by reacting maleic acid and ammonia in a stoichiometric excess, with a diamine or a triamine, at 120.degree.-350.degree. C., preferably 180.degree.-300.degree. C., and then converting the copolymer of polysuccinimide formed to a salt of a copolymer of polyaspartic acid by hydrolysis with a hydroxide.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: February 15, 1994
    Assignee: SRCHEM Incorporated
    Inventor: Louis L. Wood
  • Patent number: 5266305
    Abstract: Copolymers of polyamino acids formed by reaction of polysuccinimide with alkyl, alkenyl, aromatic amines or alkyl and alkenyl polyamines are useful as inhibitors of tartar deposition. Such compounds may be used in conventional dentrifice compositions to prevent tartar deposition on natural or false teeth.
    Type: Grant
    Filed: October 29, 1992
    Date of Patent: November 30, 1993
    Assignee: SRCHEM Incorporated
    Inventors: Louis L. Wood, Gary J. Calton
  • Patent number: 5260066
    Abstract: A controlled-release bandage containing therapeutic agents in a poly(vinyl alcohol) cryogel is disclosed. The bandage may include particulate absorbants such as ion exchange resins and hydrophobic particles to further insure controlled and constant release of therapeutic agents. The bandage may also include plasticizing agents to provide softness in the event of drying the bandage.
    Type: Grant
    Filed: January 16, 1992
    Date of Patent: November 9, 1993
    Assignee: SRCHEM Incorporated
    Inventors: Louis L. Wood, Gary J. Calton