Rohm and Haas Company

William M Hann

Barry Weinstein

John Natoli

Susan Tabb Robertson

Graham Swift

Yi H Paik

Jean Dupre

Judy H Bardsley

Tirthankar Ghosh

Jan Edward Shulman

David Richard Amick

Michael B Freeman

Kathleen J King

A new class of polymeric corrosion inhibiting compositions incorporating pendant heterocyclic groups which are surprisingly effective copper corrosion inhibitors are disclosed. The polymers form a protective barrier on metallic components to aqueous systems and remain substantive on metallic surfaces over a wide pH range. Moreover, the polymers are resistant to oxidizing biocides, and are substantially impervious to repeated or prolonged exposure to corrosive agents.

Corrosion inhibiting compositions

A method for inhibiting barium sulfate precipitation in low pH aqueous fluids of underground petroleum-bearing formations by adding to such systems an effective amount of low molecular weight water-soluble polymer containing 5-35 weight percent sulfonic acid monomer units and 65-95 weight percent carboxylic acid monomer units, is provided. Polymer compositions based on 10-15 weight percent 2-acrylamido-2-methyl-1-propanesulfonic acid, 15-65 weight percent acrylic acid and 25-70 weight percent maleic acid are particularly preferred for use at very low pH conditions, e.g., 5.5 or less in the presence of high sulfate ion and barium ion concentrations.

Method for metal sulfate scale control in harsh oilfield conditions

The present invention provides a method for inhibiting the formation of metal sulfate scale in an aqueous system. Metal sulfate scale formation is inhibited by adding an effective amount of one or more poly(amino acids) and one or more inorganic phosphates to the aqueous system. The poly(amino acids) are a reaction product formed from at least one compound selected from amino acids, amic acids, ammonium salts of monoethylenically unsaturated dicarboxylic acids, and ammonium salts of hydroxypolycarboxylic acids. The present invention also provides a method of inhibiting the formation of metal sulfate scale by adding an effective amount of a poly(amino acid) which contains tyrosine, tryptophan, histidine, arginine or combinations thereof.

Method of inhibiting sulfate scale in aqueous systems using poly(amino

The present invention provides a method of inhibiting corrosion of ferrous metals in aqueous systems. The corrosion is inhibited by adding an effective amount of one or more poly(amino acids) to the aqueous system. Aqueous systems include for example water treatment systems and equipment used for detergent applications. The poly(amino acids) comprise a reaction product of at least one compound selected from amino acids, amic acids, ammonium salts of monoethylenically unsaturated dicarboxylic acids, ammonium salts of hydroxypolycarboxylic acids and combinations thereof. In one embodiment the poly(amino acids) are added to detergent solutions to inhibit corrosion in equipment for detergent applications. In another embodiment, corrosion inhibitors comprising one or more homopolymers of amino acids and one or more pyrophosphates are added to aqueous systems to inhibit corrosion.

Method of inhibiting corrosion in aqueous systems using poly(amino acids)

A process for stabilizing aqueous systems containing scale-forming salts by adding to such systems an effective amount of selected low molecular weight water-soluble polymers containing from 30 to 60 weight percent unsaturated sulfonic acid units, from 35 to 65 weight percent carboxylic acid units and optionally up to 10 weight percent of one or more units selected from non-ionizable monomers, is provided. The polymers used in the process provide improved phosphate and iron stabilization at high temperature conditions. A polymer composition based on 50/50 weight/weight 2-acrylamido-2-methyl-1-propanesulfonic acid/acrylic acid is particularly preferred for use at high temperatures, for example, from 80.degree. to 100.degree. C.

Method for prevention of scale formation in aqueous systems

A method for solubilizing colloidal silica in aqueous systems containing silica is provided wherein a silica-containing sample is diluted, one or more chelants are added and the pH is above 10.0.

Method for solubilizing silica

A method for inhibiting silica scale formation in aqueous systems using selected low molecular weight (meth)acrylic or maleic acid based copolymers or terpolymers, magnesium ion alone, or the selected copolymers and terpolymers with aluminum ion or magnesium ion, or polyacrylic or polymaleic acid with aluminum ion or magnesium ion.

Silica scale inhibition

A process for stabilizing aqueous systems containing scale forming salts and inorganic particulates by adding to such systems an effective amount of selected low molecular weight water soluble polymers containing from about 10 to about 84 weight percent (meth)acrylic acid units, greater than 11 to less than about 40 weight percent acrylamido alkyl or aryl sulfonate units and from at least about 5 to about 50 weight percent of one or more units selected from vinyl esters, vinyl acetate and substituted acrylamides, is provided. The terpolymers and interpolymers used in the process provide improved phosphate, iron and zinc stabilization while maintaining their water solubility. Certain preferred polymers also exhibit a high degree of hydrolytic stability at high pH conditions.

Method of stabilizing aqueous systems

A method for inhibiting scale formation in aqueous systems using water-soluble, low molecular weight copolymers of unsaturated aliphatic carboxylic acids is provided. Copolymers formed from about 30 to about 70 weight percent acrylic acid and from about 70 to about 30 weight percent methacrylic acid, having a weight average molecular weight ranging from about 2000 to about 5000, are preferred for inhibiting the formation of common hardness ion salt scale such as calcium carbonate, calcium phosphate and barium sulfate. The copolymers are hydrolytically stable and can be used effectively in high temperature applications. The copolymers are also effective dispersants for suspended inorganic particulate materials, such as clay, in aqueous systems.

Method of inhibiting scaling in aqueous systems with low molecular

A method for dispersing inorganic materials in aqueous systems using water soluble, low molecular weight copolymers of acrylic acid is provided. Copolymers having a weight average molecular weight of from about 2,000 to about 5,000 formed from about 85 to about 97 weight percent acrylic acid and from about 3 to about 15 weight percent of a hydrophobic comonomer are provided for effective dispersion of suspended particulate matter, such as clay, and for inhibiting the precipitation of common hardness ion salts in aqueous systems. The most preferred copolymers have a weight average molecular weight of about 3,000 and are formed from about 95 weight percent acrylic acid and about 5 weight percent ethyl acrylate.

Method of dispersing inorganic materials in aqueous systems with low

The application discloses a viscous aqueous alkaline drilling liquid (fluid) essentially free of clays, for drilling subterranean wells, and a method of drilling such wells. The fluid is circulated into and out of the well, to flush out drill cuttings. The alkaline composition comprises a combination of the thickeners (a) 10 to 90 parts by weight of an addition polymer of an unsaturated carboxylic acid, preferably in the form of a copolymer with another ethylenically unsaturated monomer, for example a copolymer of a major amount of methacrylic acid and a minor amount of ethyl acrylate, the polymer having a molecular weight of from 125,000 to 12,000,000 solubilized in the aqueous system by an alkali such as sodium carbonate, and (b) 10 to 90 parts by weight of a water soluble polysaccharide, or a water soluble derivative thereof ('polysaccharide' being used herein in a generic sense to include such derivatives) such as hydroxyethyl cellulose, the total amount of (a) plus (b) being 100 parts.

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Gwynedd, PA, United States of America

William M Hann