Nitrogen Containing Patents (Class 210/700)
  • Patent number: 4552665
    Abstract: The instant invention is directed to a process for inhibiting the precipitation of dissolved manganese ion and its reaction products in aqueous solutions, comprising adding to the aqueous solution 0.1 to 20 ppm of a copolymer of an unsaturated carboxylic acid or salt selected from the group consisting of acrylic acid and methacrylic acid and an unsaturated sulphonic acid or salt selected from the group consisting of 2-acrylamido-2-methylpropylsulphonic acid and 2-methacrylamido-2-methylpropylsulphonic acid.
    Type: Grant
    Filed: May 4, 1984
    Date of Patent: November 12, 1985
    Assignee: Calgon Corporation
    Inventors: Paul H. Ralston, Sandra L. Whitney
  • Patent number: 4551262
    Abstract: The present invention relates to a composition for preventing deposition of inorganic salts. The composition incorporates 0.1-4.5% by weight and 1,3-diaminopropanol-2 and/or of a derivative of 1,3-diaminopropanol-2 of the general formula: ##STR1## wherein n=2 to 20, 5.0-50.0% by weight of a phosphonomethylated derivative of 1,3-diaminopropanol-2 in the form of a salt of an alkali metal and/or ammonium salt of the general formula: ##STR2## wherein n=1 to 20, M is an alkali metal or NH.sub.4, 3.0-12.0% by weight of an alkali metal chloride, ammonium chloride or a mixture of both and water to 100%. The composition effectively prevents scaling of inorganic salts, e.g. barium sulphate, calcium sulphate and calcium carbonate.
    Type: Grant
    Filed: October 5, 1983
    Date of Patent: November 5, 1985
    Inventors: Rafail K. Samakaev, Alexandr I. Paguba, Nikolai V. Smolnikov, Leonid T. Dytjuk, Vladimir I. Gusev, Nina M. Dyatlova, Galina F. Yaroshenko, Anatoly V. Barsukov, Ljudmila V. Krinitskaya, Taisia M. Balashova
  • Patent number: 4547294
    Abstract: Formation of alkaline scale on cooling tower and associated heat transfer surfaces contacted by circulating water is reduced or substantially eliminated while minimizing equipment corrosion by introducing an effective amount of carbon dioxide and a threshold effect chemical scale control additive to the circulating water.
    Type: Grant
    Filed: January 19, 1984
    Date of Patent: October 15, 1985
    Assignee: Mechanical Equipment Company, Inc.
    Inventor: Richard W. Goeldner
  • Patent number: 4534866
    Abstract: A water system deposit control method and composition of high calcium tolerance are herein disclosed. The composition comprises a reaction product formed from acrylic acid, hydroxylated lower alkyl acrylate and hypophosphorous acid. In accordance with the method herein, an effective amount, from about 0.1-500 ppm of the composition is added to the water system, e.g., cooling water system, so as to inhibit the build-up or agglomeration of undesirable deposits along the metal surfaces on contact with the water.
    Type: Grant
    Filed: February 17, 1983
    Date of Patent: August 13, 1985
    Assignee: Betz Laboratories, Inc.
    Inventor: Larry W. Becker
  • Patent number: 4526728
    Abstract: 2-(Meth)acrylamido-2-methylpropanephosphonic acid is prepared by reaction of 2-methylprop-1-ene-1-phosphonic acid or 2-methylpro-2-ene-1-phosphonic acid with (meth)acrylonitrile in the presence of an equimolar amount of a strong acid. The compounds are suitable as such or in the form of their salts as comonomer for the manufacture of copolymers, which are used inter alia as dyeing auxiliaries and as scale inhibitors.
    Type: Grant
    Filed: April 5, 1984
    Date of Patent: July 2, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Manfred Finke, Walter Rupp, Erwin Weiss
  • Patent number: 4525293
    Abstract: The present invention relates to a composition for preventing deposition of inorganic salts. It comprises 5.0-50.0% by weight of a phosphonomethylated derivative of 1,3-diaminopropanol-2 of the general formula: ##STR1## wherein n=1 to 20; 5.0 to 10.0% by weight of 1,3-diaminopropanol-2 and/or a derivative of 1,3-diaminopropanol-2 of the general formula: ##STR2## wherein n=1 to 20; 3.0-30.0% by weight of hydrochloric acid, 3.0-7.0% by weight of an alkali metal chloride, 0.5-2.5% by weight of a product of interaction of benzyl chloride, chlorobenzyl chloride, benzylidene chloride or a mixture of these chlorinated compounds with hexamethylenetetramine at a molar ratio thereof equal to 1:0.25-0.45 respectively; 0.5-4.0% by weight of a water-soluble organic solvent and water being the balance. The protective effect of the composition against deposition of inorganic salts is as high as 100%. The freezing point is as low as -100.degree. C.
    Type: Grant
    Filed: October 3, 1983
    Date of Patent: June 25, 1985
    Inventors: Evgeny D. Kisil, Svetlana N. Komova, Olga A. Kulikova, Leonid I. Kutyanin, Larisa V. Popova, Nina M. Dyatlova, Rostislav P. Lastovsky, Galina F. Yaroshenko, Rem A. Khramov, Leonid T. Dytjuk, Rafail K. Samakaev, Anatoly N. Vasnev
  • Patent number: 4518777
    Abstract: Certain methylene phosphonic acid derivatives of aminohydrocarbyl piperazine-urea adducts are good threshold agents to prevent metal ion precipitation in aqueous solutions.
    Type: Grant
    Filed: September 2, 1983
    Date of Patent: May 21, 1985
    Assignee: The Dow Chemical Company
    Inventors: Druce K. Crump, David A. Wilson
  • Patent number: 4514186
    Abstract: The invention relates to aqueous dyestuff formulations which contain at least one telomer of the formula I ##STR1## or a salt thereof, in addition to at least one anionic dispersant and optionally further ingredients. In formula I the symbols have the following meanings: X is hydrogen or ##STR2## Y is hydrogen, --SO.sub.4 H or ##STR3## each of R.sub.1 and R.sub.2 independently of the other is hydrogen, C.sub.1 -C.sub.4 alkyl which is unsubstituted or substituted by a carboxyl group or is carboxyl; and the sum of n+m is an integer from 2 to 350. These compositions have good storage stability and redispersibility and are particularly suitable for use in the continuous dyeing process.
    Type: Grant
    Filed: October 25, 1983
    Date of Patent: April 30, 1985
    Assignee: Ciba Geigy Corporation
    Inventors: Alain Lauton, Zdenek Koci
  • Patent number: 4501667
    Abstract: Process for conditioning metal surfaces to inhibit their corrosion and/or to inhibit scale deposition thereon by treating said surfaces:A. prior to contact with a corrosive or scaling environment, with(i) compound having the formula I: ##STR1## or a water-soluble salt (or partial ester or -salt) thereof, wherein R.sub.1 and R.sub.2 are the same or different and each is hydrogen, a C.sub.1 -C.sub.12 straight- or branched chain alkyl group (optionally substituted by one or more hydroxy- and/or carboxyl groups and/or optionally interrupted by one or more oxygen atoms), a C.sub.3 -C.sub.12 straight- or branched chain alkenyl group, a C.sub.7 -C.sub.15 aralkyl group or --CH.sub.2 PO.sub.3 H.sub.2, or R.sub.1 and R.sub.2, together with the nitrogen atom to which they are each bonded, may form an optionally-substituted heterocyclic ring; R.sub.3 is hydrogen, a C.sub.1 -C.sub.12 straight- or branched chain alkyl group or an optionally substituted C.sub.6 -C.sub.10 aryl group; and R.sub.4 is hydrogen or C.sub.1 -C.
    Type: Grant
    Filed: February 21, 1984
    Date of Patent: February 26, 1985
    Assignee: Ciba-Geigy Corporation
    Inventor: Barry Cook
  • Patent number: 4500470
    Abstract: New compounds have been prepared from dicyclopentadiene bis(methylamine) which have the following formula ##STR1## wherein substituents A, B, X and Y each are independently selected from radicals including hydrogen, hydroxyalkyl (wherein the alkyl group contains 2-6 carbon atoms) phosphonic, sulfonic, hydroxyethyl- and hydroxypropyl-sulfonic, methylenephosphonic methylene-, ethylene- and propylenesulfonic, alkylcarboxylic acid radicals (having 2-4 carbon atoms) and the alkali or alkaline earth metal, ammonia and amine salts of any of the phosphonic, sulfonic or carboxylic acid derivatives. At least one of the substituents must be other than a hydrogen.
    Type: Grant
    Filed: April 18, 1983
    Date of Patent: February 19, 1985
    Assignee: The Dow Chemical Company
    Inventor: David A. Wilson
  • Patent number: 4500469
    Abstract: The bis(methylamine) of norbornane compounds which have at least one of the amine hydrogens substituted with hydroxyalkyl, methylenephosphonic, alkylenesulfonic, carboxylic acid radicals and salts of any of the acid radicals are useful as chelating, sequestering agents. The phosphonate substituted compounds are also useful as threshold agents.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: February 19, 1985
    Assignee: The Dow Chemical Company
    Inventors: Jaime Simon, Druce K. Crump, David A. Wilson
  • Patent number: 4497713
    Abstract: A corrosion inhibition and scale control method and composition are disclosed. The method comprises, adding to a cooling water system, for which protection is desired, a water soluble zinc salt, a cellulose gum material and an organo-phosphorus acid compound. Optionally, a corrosion inhibitor compound such as a 1,2,3-triazole or thiazole compound may be added to afford additional protection. Molybdate salts may also be included as optional corrosion inhibitors.
    Type: Grant
    Filed: April 1, 1982
    Date of Patent: February 5, 1985
    Inventor: Gary E. Geiger
  • Patent number: 4493771
    Abstract: Compounds having improved properties of inhibiting the precipitation of metal ions when used in threshold amounts have been made which are derivatives of ammonia or di- or polyamines in which the amine hydrogens have been substituted with both methylenephosphonic acid groups or their salts and hydroxypropyl quaternaryammonium halide groups. Thus, ammonia can have two hydrogens replaced with methylenephosphonic groups while the third is replaced with a hydroxypropyltrimethylammonium chloride group; and three hydrogens of ethylenediamine can be replaced with methylenephosphonic groups, the fourth being replaced with a hydroxypropyltrimethylammonium chloride group.
    Type: Grant
    Filed: March 6, 1984
    Date of Patent: January 15, 1985
    Assignee: The Dow Chemical Company
    Inventors: David A. Wilson, Wilfred W. Wilson
  • Patent number: 4489203
    Abstract: New polymers which are the reaction product of aminoethylpiperazine and a dihalo or epoxyhalo compound are subsequently phosphonomethylated to provide products which are useful as threshold ion control agents.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: December 18, 1984
    Assignee: The Dow Chemical Company
    Inventors: David A. Wilson, Druce K. Crump
  • Patent number: 4459241
    Abstract: Compounds having improved properties of inhibiting the precipitation of metal ions when used in threshold amounts have been made which are derivatives of ammonia or di- or polyamines in which the amine hydrogens have been substituted with both methylenephosphonic acid groups or their salts and hydroxypropyl quaternaryammonium halide groups. Thus, ammonia can have two hydrogens replaced with methylenephosphonic groups while the third is replaced with a hydroxypropyltrimethylammonium chloride group; and three hydrogens of ethylenediamine can be replaced with methylenephosphonic groups, the fourth being replaced with a hydroxypropyltrimethylammonium chloride group.
    Type: Grant
    Filed: April 28, 1983
    Date of Patent: July 10, 1984
    Assignee: The Dow Chemical Company
    Inventors: David A. Wilson, Wilfred W. Wilson
  • Patent number: 4446028
    Abstract: A water soluble isopropenylphosphonic acid copolymer composition and method of use thereof are disclosed. The copolymer comprises repeat units (a) of the formula ##STR1## wherein X=OH or OM, wherein M is a cation; and repeat units (b) of the formula ##STR2## wherein R.sub.1 is chosen from the group consisting of hydroxy, hydroxylated alkoxy, and amide and water soluble salts thereof; R.sub.2 is H, or lower alkyl of from 1-3 carbon atoms. These copolymers are effective in inhibiting the precipitation of certain scale forming salts, and also act to inhibit corrosion in water systems.
    Type: Grant
    Filed: December 20, 1982
    Date of Patent: May 1, 1984
    Assignee: Betz Laboratories, Inc.
    Inventor: Larry W. Becker
  • Patent number: 4444675
    Abstract: Formation of alkaline scale in water distillation equipment is reduced or substantially eliminated without a significant increase in equipment corrosion rate by dissolving an effective amount of carbon dioxide in brine which is boiling or flashed or which has been boiled or flashed and which contains an effective amount of a high temperature threshold effect chemical scale control additive.
    Type: Grant
    Filed: February 18, 1982
    Date of Patent: April 24, 1984
    Assignee: Mechanical Equipment Company, Inc.
    Inventor: Richard W. Goeldner
  • Patent number: 4420399
    Abstract: This invention relates to quaternary aminomethyl phosphonates and uses thereof for example as scale inhibitors, corrosion inhibitors, chelating agents, etc.
    Type: Grant
    Filed: May 28, 1982
    Date of Patent: December 13, 1983
    Assignee: Petrolite Corporation
    Inventor: Derek Redmore
  • Patent number: 4416785
    Abstract: Compositions which will inhibit the formation of scale due to calcium carbonate precipitation in recirculating water systems will comprise a mixture of polyvinylpyrrolidone and aminotri(methylenephosphonic acid). The compositions will be present in the water system in a range of from about 2 to about 25 ppm of said system and will contain the components of the composition in a mole ratio in the range of from about 1: to about 1:10 moles of polyvinylpyrrolidone per mole of phosphonic acid.
    Type: Grant
    Filed: May 17, 1982
    Date of Patent: November 22, 1983
    Assignee: UOP Inc.
    Inventors: Russell O. Menke, Michael Bortnik
  • Patent number: 4401587
    Abstract: A method of inhibiting corrosion of low carbon steel in an aqueous system comprising treating said system with 1.0 to 300 parts per million by weight of the total aqueous content of said system, of a composition comprising aminomethylphosphonic acid compounds and polymaleic anhydride or amine adducts thereof in a weight ratio of from 10:1 to 1:10.
    Type: Grant
    Filed: December 16, 1981
    Date of Patent: August 30, 1983
    Assignee: Calgon Corporation
    Inventor: Bennett P. Boffardi
  • Patent number: 4384979
    Abstract: The waters used for cooling generally contain hard ions of the group consisting of calcium and magnesium ions concentration of from about 10 to 600 parts per million. Such waters also contain bicarbonate ions. When cooling waters are recirculated through a cooling tower, they are saturated with oxygen and tend to be corrosive and tend to promote formation of calciferous scale. Such propensities are inhibited by the injection of appropriate chemicals so that the inhibited water contains dispersants effective in dispersing incipient calcium compounds and inhibiting calciferous scale, so that the inhibited water contains a plurality of components forming a dynamic layer on metal surfaces protecting such metal from oxidation.
    Type: Grant
    Filed: November 4, 1981
    Date of Patent: May 24, 1983
    Assignee: Atlantic Richfield Company
    Inventor: Gerald D. Hansen
  • Patent number: 4330487
    Abstract: This invention relates to a process of preparing N,N'-disubstituted methylene phosphonic acids by reacting .alpha., .omega.-alkylene diamines with essentially 2 equivalents of formaldehyde and phosphorus acid based on replaced nitrogen-bonded hydrogens.This invention also relates to compositions formed by the process and to the uses for these compositions such as for inhibiting scale, etc.
    Type: Grant
    Filed: October 29, 1980
    Date of Patent: May 18, 1982
    Assignee: Petrolite Corporation
    Inventors: Derek Redmore, William S. Paley
  • Patent number: 4328180
    Abstract: The waters used for cooling generally contain hard ions of the group consisting of calcium and magnesium ions concentration of from about 10 to 600 parts per million. Such waters also contain bicarbonate ions. When cooling waters are recirculated through a cooling tower, they are saturated with oxygen and tend to be corrosive and tend to promote formation of calciferous scale. Such propensities are inhibited by the injection of appropriate chemicals so that the inhibited water contains dispersants effective in dispersing incipient calcium compounds and inhibiting calciferous scale, so that the inhibited water contains a plurality of components forming a dynamic layer on metal surfaces protecting such metal from oxidation.
    Type: Grant
    Filed: October 31, 1980
    Date of Patent: May 4, 1982
    Assignee: Atlantic Richfield Company
    Inventor: Gerald D. Hansen
  • Patent number: 4328106
    Abstract: A method for inhibiting silica scaling and precipitation in geothermal flow systems by on-line injection of low concentrations of cationic nitrogen-containing compounds, particularly polymeric imines, polymeric amines, and quaternary ammonium compounds.
    Type: Grant
    Filed: June 13, 1980
    Date of Patent: May 4, 1982
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Jackson E. Harrar, Lyman E. Lorensen, Frank E. Locke
  • Patent number: 4323460
    Abstract: This invention relates to .alpha.-1,4-thiazine alkanephosphonic acids; and to the preparation and uses thereof in inhibiting scale formation in aqueous systems.
    Type: Grant
    Filed: October 2, 1980
    Date of Patent: April 6, 1982
    Assignee: Petrolite Corporation
    Inventor: Patrick M. Quinlan
  • Patent number: 4323461
    Abstract: This invention relates to novel di-quaternary ammonium salts of .alpha.-1,4-thiazine alkanephosphonic acids; the preparation thereof; and uses thereof in inhibiting scale formation in aqueous systems.
    Type: Grant
    Filed: October 14, 1980
    Date of Patent: April 6, 1982
    Assignee: Petrolite Corporation
    Inventor: Patrick M. Quinlan
  • Patent number: 4323459
    Abstract: This invention relates to quaternary ammonium salts of .alpha.-1,4-thiazine alkanephosphonic acids; and to the preparation and uses thereof in inhibiting scale formation in aqueous systems.
    Type: Grant
    Filed: September 15, 1980
    Date of Patent: April 6, 1982
    Assignee: Petrolite Corporation
    Inventor: Patrick M. Quinlan
  • Patent number: 4308147
    Abstract: Disclosed are a composition and method for treating aqueous solutions with N-carboxy alkyl amino alkane polyphosphonic acids which have more than two carbon atoms in their carboxy alkyl group, and their alkali metal salts. The acids and salts are prepared in a good yield by reacting alkali metal salts of amino alkane phosphonic acids in which at least one hydrogen atom of the amino group is unsubstituted, in an alkaline medium with an .alpha.,.beta.-unsaturated carboxylic acid at increased temperature. The free acids are preferably recovered from the reaction solution by a treatment with a cation exchange agent. In place of the .alpha.,.beta.-unsaturated carboxylic acids there can also be used their anhydrides, esters, or nitriles. The resulting polyphosphonic acids have a good complexing or sequestering effect on polyvalent metal ions.
    Type: Grant
    Filed: November 7, 1979
    Date of Patent: December 29, 1981
    Assignee: Benckiser-Knapsack GmbH
    Inventors: Klaus Sommer, Hermann Weber
  • Patent number: 4307038
    Abstract: Novel N-carboxy alkyl amino alkane polyphosphonic acids which have more than two carbon atoms in their carboxy alkyl group, and their alkali metal salts are prepared in a good yield by reacting alkali metal salts of amino alkane phosphonic acids in which at least one hydrogen atom of the amino group is unsubstituted, in an alkaline medium with an .alpha., .beta.-unsaturated carboxylic acid at increased temperature. The free acids are preferably recovered from the reaction solution by a treatment with a cation exchange agent. In place of the .alpha., .beta.-unsaturated carboxylic acids there can also be used their anhydrides, esters, or nitriles. The resulting polyphosphonic acids have a good complexing or sequestering effect on polyvalent metal ions.
    Type: Grant
    Filed: July 20, 1978
    Date of Patent: December 22, 1981
    Assignee: Benckiser-Knapsack GmbH
    Inventors: Klaus Sommer, Hermann Weber
  • Patent number: 4297237
    Abstract: A method of inhibiting corrosion in an aqueous system comprising treating said system with 1.0 to 300 parts per million by weight of the total aqueous content of said system, of a composition comprising polyphosphate and polymaleic anhydride or amine adducts thereof in a weight ratio of from 10:1 to 1:10.
    Type: Grant
    Filed: March 6, 1980
    Date of Patent: October 27, 1981
    Assignee: Calgon Corporation
    Inventor: Bennett P. Boffardi
  • Patent number: 4279758
    Abstract: A process for inhibiting the formation of mineral deposits from a water using novel N,N'-dialkylureidomethane diphosphonic acids and their alkaline salts having the formula: ##STR1## wherein R.sub.1 and R.sub.2 represent separate alkyl groups having one to three carbon atoms or a ring-forming alkylene group having two or three carbon atoms and R is hydrogen or an alkali metal.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: July 21, 1981
    Assignee: Joh. A. Benckiser GmbH
    Inventors: Friedrich Kruger, Walter Michel
  • Patent number: 4255259
    Abstract: This invention relates to an improved method for inhibiting deposition of scale in aqueous systems. More specifically, it relates to the use of small quantities of an improved composition for preventing formation of scale and sludge deposits in steam generating boilers. The composition is characterized by the fact that by using a plurality of selected ingredients a synergistic effect is obtained. The ingredients comprise a copolymer of styrene sulfonic acid and maleic anhydride or maleic acid, along with a water soluble organophosphonic acid compound.
    Type: Grant
    Filed: September 18, 1979
    Date of Patent: March 10, 1981
    Assignee: Chemed Corporation
    Inventors: Chih M. Hwa, Dionisio G. Cuisia
  • Patent number: 4250107
    Abstract: N-(sulfo alkane) amino alkane phosphonic acids or their water-soluble salts are obtained by reacting an alkali metal salt of an amino alkane phosphonic acid with at least one hydrogen atom in the amino group which can be replaced by a sulfo alkane group, in an alkaline medium with an alkane sultone while heating.
    Type: Grant
    Filed: November 6, 1978
    Date of Patent: February 10, 1981
    Assignee: Benckiser-Knapsack GmbH
    Inventors: Klaus Sommer, Gottfried Schoebel
  • Patent number: 4243524
    Abstract: Aminoalkylenephosphonic acids and their alkali metal salts prepared by a reaction utilizing a primary or secondary tetrahydrothiophenamine 1,1-dioxide or the hydrochloride thereof, an aldehyde or a ketone, and orthophosphorous acid are useful in the control of scale and sludge deposition in aqueous systems. When used in combination with known corrosion inhibitors they show synergistic results in inhibiting corrosion of metal surfaces in contact with an aqueous system that is normally corrosive to such metals.
    Type: Grant
    Filed: August 2, 1979
    Date of Patent: January 6, 1981
    Assignee: Buckman Laboratories, Inc.
    Inventors: Joseph G. E. Fenyes, John D. Pera
  • Patent number: 4239695
    Abstract: Amino-phosphonates typified by the general formula R--C(PO(OH).sub.2).sub.2 NH.sub.2 are prepared by reacting phosphorous acid with nitriles at elevated temperatures.
    Type: Grant
    Filed: March 24, 1977
    Date of Patent: December 16, 1980
    Assignee: Magna Corporation
    Inventors: Bong J. Chai, Fred D. Muggee
  • Patent number: 4234511
    Abstract: Dialkylamino-N,N-bis(phosphonoalkylene)alkylamines, salts, and specifically the hydrochlorides thereof prepared by reacting an unsymmetrical dimethylaminoalkylamine hydrochloride with phosphorous acid and an aldehyde are useful in various industrial processes including acting as corrosion and scale inhibitors in aqueous systems wherein such corrosion and scale problems exist. Quaternized dialkylamino-N,N-bis(phosphonoalkylene)alkylamines suitable for the same uses are prepared by the treatment of an aqueous solution of a dialkylamine-N,N-bis(phosphonoalkylene)alkylamine with an epoxide or a halohydrin.
    Type: Grant
    Filed: July 26, 1979
    Date of Patent: November 18, 1980
    Assignee: Buckman Laboratories, Inc.
    Inventor: John D. Buckman
  • Patent number: 4231894
    Abstract: The present invention is directed to a method of stabilizing aqueous solutions containing alkali metal sulfite or bisulfite and a catalyst therefor. The catalyzed sulfites which are of primary concern in the present instance are those which are used to inhibit or control oxygen corrosion in water treatment, particularly boiler water treatment.
    Type: Grant
    Filed: January 17, 1980
    Date of Patent: November 4, 1980
    Assignee: Betz Laboratories, Inc.
    Inventors: Walter M. Lavin, James I. McFarlane, Dennis L. Rose
  • Patent number: 4229294
    Abstract: This invention relates to the use of compounds for inhibiting scale formation, said compounds being characterized by the presence of N-methyl, or substituted methyl, phosphonic acid and N-hydroxy-propylenesulfonic acid groups. These compounds contain at least one or more of each group and are bonded to the same or different amino groups. They are derived by reacting an amine with both (1) an epihalohydrin-bisulfite addition product and (2) with a carbonyl compound, such as formaldehyde, and phosphorous acid or its equivalent.They have a wide variety of uses, for example as scale and corrosion inhibitors, iron oxide removers, chelating agents, etc.
    Type: Grant
    Filed: May 24, 1979
    Date of Patent: October 21, 1980
    Assignee: Petrolite Corporation
    Inventors: Derek Redmore, Frederick T. Welge