W. R. Grace Co.

W. R. Grace Co.-conn.

Patricia M Scanlon

Roger R Gaudette

John Leonard Ohlson

Chih M Hwa

John A Kelly

Janet Neton

E Richard Young

This invention relates to controlling corrosion in aqueous systems and more particularly to using certain calcium insensitive phosphonomethyl amine oxide compounds. The compounds of this invention are water soluble phosphonomethyl amine oxides having at least one oxidized tertiary amine group of the formula: ##STR1## and water soluble salts thereof and having a cloud point of at least about 25 ppm.

Control of corrosion in aqueous systems using certain phosphonomethyl

This invention relates to controlling scale formation in aqueous systems and more particularly to using certain calcium insensitive phosphonomethyl amine oxide compounds having at least one oxidized tertiary amine group of the formula: ##STR1## and water soluble salts thereof.

Control of scale in aqueous systems using certain phosphonomethyl amine

This invention relates to certain calcium insensitive phosphonomethyl amine compounds and their use as scale control agents for treating aqueous systems. The compounds of this invention are water-soluble phosphonomethyl amine compounds having the formula: ##STR1## and water soluble salts thereof selected from the group consisting of N-phosphonomethyl iminodiacetic acid, N,N-bis-phosphonomethyl- 2-(hydroxyethoxy)ethylamine, 4-(phosphonomethyl)-2-hydroxy-2-oxo-1,4,2-oxazaphosphorinane, N,N-bis-phosphonomethyl taurine and N,N-bis-phosphonomethyl ethylamine; and having a cloud point of at least about 25 ppm as determined by the CA500 cloud point test or a water soluble salt of said phosphonomethyl amine.

Control of scale in aqueous systems using certain phosphonomethyl amines

This invention relates to novel organic phosphonate compounds which can be used as water treatment agents. More specifically, this invention relates to the compound N,N-bis-phosphonomethyl taurine N-oxide which may be represented by the formula: ##STR1## and its water soluble salts, which can be employed for the control of scale and/or corrosion.

N,N-bis-phosphonomethyl taurine N-oxide and water-soluble salts thereof

This invention relates to a method for preventing corrosion and inhibiting the formation of scale deposition in aqueous systems. More specifically, it relates to using certain calcium insensitive phosphonomethyl amine compounds having the formula: ##STR1## wherein either R.sub.1 is selected from hydrogen, hydrocarbyl, hydroxy-substituted hydrocarbyl, alkoxy-substituted hydrocarbyl; and R.sub.2 is selected from hydrocarbyl, hydroxy-substituted hydrocarbyl, alkoxy-substituted hydrocarbyl, carboxyl-substituted hydrocarbyl, --CH.sub.2 PO.sub.3 H.sub.2, and --C.sub.2 H.sub.4 N(CH.sub.2 PO.sub.3 H.sub.2).sub.2 ; or R.sub.1 and R.sub.2 together form an alicyclic ring having 3 to 5 carbon atoms, optionally along with oxygen atoms, phosphorus atoms or both oxygen and phosphorus atoms in the ring, and water soluble salts thereof.

Alkyl-substituted hydroxy benzyl amino acid oligomers are effective metal chelating agents in a broad range of non-aqueous systems. The products claimed display surprisingly high solubilities in a broad range of substituted and unsubstituted aliphatic and aromatic solvents.

Chelating agents for non-aqueous systems

A process for preparing in high yield an isolable orthohydroxydiaminodicarboxylic acid which is useful as a metal chelating agent. The process comprises reacting a phenol (or mixture of phenols), a diaminodicarboxylic acid (or acid source), and a formaldehyde source in a medium having an acidic pH.

Process for preparing chelating agents

A novel chelating agent having the formula ##STR1## (a) each of X.sub.1, X.sub.2, X.sub.3, and X.sub.4 is a member selected from the group consisting of (i) hydrogen; (ii) an alkyl group having 1-4 carbon atoms; (iii) --CN; (iv) --SO.sub.3 M.sub.1 ; (v) --COOM.sub.1 ; (vi) --OM.sub.3 ; (vii) --NO.sub.2 ; (viii) --OH; and ##STR2## in which each of R.sub.1 and R.sub.2 is an alkyl group having 1-4 carbon atoms;

N,N'Di(hydroxybenzyl) 1,3-propanediamine N,N'-diacetonitriles

An iron, copper, cobalt, manganese, chromium, nickel, zinc, cadmium, molybdenum, or lead chelate of a novel chelating agent having the formula ##STR1## in which (A) EACH OF X.sub.1, X.sub.2, X.sub.3, and X.sub.4 is a member selected from the group consisting of (i) hydrogen; (ii) an alkyl group having 1-4 carbon atoms; (iii) --CN; (iv) --SO.sub.3 M.sub.1 ; (v) --COOM.sub.1 ; (vi) --OM.sub.3 ; (vii) --NO.sub.2 ; (viii) --OH; and ##STR2## IN WHICH EACH OF R.sub.1 and R.sub.2 is an alkyl group having 1-4 carbon atoms;

Metal chelates

A novel chelating agent having the formula ##STR1## in whichA. EACH OF X.sub.1, X.sub.2, X.sub.3, and X.sub.4 is a member selected from the group consisting of (i) hydrogen; (ii) an alkyl group having 1-4 carbon atoms; (iii) --CN; (iv) --So.sub.3 M.sub.1 ; (v) --COOM.sub.1 ; (vi) --OM.sub.3 ; (vii) --NO.sub.2 ; (viii) --OH; and (ix) ##STR2## in which each of R.sub.1 and R.sub.2 is an alkyl group having 1-4 carbon atoms;

N,N-di-(hydroxybenzyl)-trimethylene diaminediacetic acids

N,N'-Dicarboxymethyl-1,3-propanediamine (designated PDDA) is prepared by reacting 1,3-propanediamine with formaldehyde and HCN to form hexahydropyrimidine-1,3-diacetonitrile, which is hydrolyzed with an aqueous alkali metal hydroxide to form dialkali metal hexahydropyrimidine-1,3-diacetate which, in turn, is reacted with mineral acid to form the desired PDDA and formaldehyde. N,n'-dicarboxymethyl-2-hydroxy-1,3-propanediamine (designated HYDROXY-PDDA) is prepared by reacting 1,3-diamino-2-propanol with formaldehyde and HCN to form 5-hydroxyhexahydropyrimidine-1,3-diacetonitrile, which is hydrolyzed with an aqueous alkali metal hydroxide to form dialkali metal 5-hydroxyhexahydropyrimidine-1,3-diacetate which, in turn, is reacted with acid to form the desired HYDROXY-PDDA and formaldehyde.

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Arlington, MA, United States of America

Patricia M Scanlon