Abstract: There is disclosed herein improved processes for the preparation of ether carboxylates by reacting in an alkaline reaction medium the salts of maleic acid and malic acid in the presence of a calcium ion catalyst wherein unreacted acid salts are recovered from the reaction medium by lowering the pH of the reaction medium to a range of from about 4 to about 6 in two steps, the first step ending at a pH in the range of from about 7 to about 8.5. The precipitate is removed and the pH of the reaction medium is then lowered further to a pH in the range of from 4 to 6. The precipitated salts are recycled to the synthesis reaction to prepared additional amounts of product.

Abstract: There is disclosed a method for purifying the product of a calcium catalyzed reaction, in alkaline reaction medium of salts of maleic acid a hydroxy acid wherein impurities are removed by single stage solvent extraction and separation of the raffinate.

Abstract: A process for the preparation of mixed salts of oxydissuccinate/carboxymethyloxysuccinate is disclosed, which process comprises adding glycolic acid to an aqueous mixture obtained from a 2,2'-oxydisuccinate forming reaction. The mixed oxydisuccinate carboxymethyloxysuccinate salts are obtained in high yields and can be used as detergent builder in cleaning compositions.

Abstract: There is disclosed an improved process for preparing 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylic acid and 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylic acid wherein the reaction mixture has a solids concentration of above about 60%, by weight whereby the amount of by-product fumarate is reduced.

Abstract: The present invention provides a composition in contact with a corrodable metal surface, comprising a functional fluid and, as corrosion inhibitor, a compound having the formula I: ##STR1## as well as salts or esters thereof, wherein R.sup.1 is C.sub.4 -C.sub.20 linear or branched alkyl, phenyl or C.sub.7 -C.sub.20 alkylphenyl;R.sup.2 is C.sub.1 -C.sub.12 linear or branched alkyl, phenyl or C.sub.7 -C.sub.20 alkylphenyl, or arylalkyl containing 7-20 carbon atoms;X is CH.sub.2, O or S;Y is O or S; andZ is --(CH.sub.2).sub.n -- in which n is 1, 2, 3, 4 or 5, or Z is --CH.sub.2 --CH(CH.sub.3)--.Some of the compounds of formula I are new.

Abstract: Biodegradable and little skin-roughening carboxylic acids being an excellent surfactant in a wide pH range and having the general formula (1): ##STR1## wherein R is a linear or branched alkyl or alkenyl group containing from 4 to 34 carbon atoms; one or both of X.sub.1 and X.sub.2 are --(CH.sub.2).sub.n --COOM, any other is a hydrogen atom; M is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, a lower alkanol amine cation, a lower alkyl-amine cation or a basic amino acid cation; and n is 1 or 2; and simple methods of preparing the same.

Abstract: There is disclosed herein improved processes for the preparation of ether carboxylates by reacting in an alkaline reaction medium the salts of maleic acid and a carboxylic or polycarboxylic acid having a reactive hydroxyl group on a non-carbonyl carbon atom in the presence of a calcium ion catalyst wherein unreacted acid salts are recovered from the reaction medium by lowering the pH of the reaction medium to a range of from about 4 to about 6. The precipitated salts are recycled to the synthesis reaction to prepare additional amounts of product.

Abstract: A process for preparing water-scale inhibitors and, more specifically, a neat process for preparing acrylic acid/ethylene glycol graft co-polymers and a method for their use as scale inhibitors.

Abstract: There is disclosed an improved process for preparing 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylic acid and 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylic acid wherein the unreacted starting acids are recovered in more desirable crystal habit. The acids are precipitated in salt form by lowering the pH of the reaction product to a range of from 4 to below 6 stepwise. The pH is lowered to above 6 in the first step and then relatively rapidly reduced to the desired level in the second step.

Abstract: There is disclosed herein improved processes for the preparation of mixtures of alkali metal salts of 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylate and alkali metal salts of 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylate wherein by-product calcium carbonate produced by the process of making such mixtures is employed in a recycle pattern to prepare additional amounts of mixtures of said compounds.

Abstract: A fluorine-containing polyether of the formula:A--X--A'wherein A and A' are the same or different and are each --COF, --COCl or --COOH, and X is --CF.sub.2 CF.sub.2 --R.sub.f --O--C.sub.m F.sub.2m --O--R.sub.f 'CF.sub.2 CF.sub.2 -- in which R.sub.f and R.sub.f ' are the same or different and are each a group containing a perfluoroalkylpolyether group, and m is a number of from 1 to 6, and a fluorine-containing polyether of the formula:Z--X.sub.n --Z'wherein X is the same as defined above, Z and Z' are the same or different and are each --COF, --COCl, --COOH or --CF.sub.2 CF.sub.2 --R.sub.f --B in which R.sub.f is the same as defined above and B is a fluorine atom or a C.sub.1 -C.sub.5 perfluoroalkyl group, and n is a number of from 0 to 100 provided that when n is 1, Z and Z' are each --CF.sub.2 CF.sub.2 R.sub.f B, provided that when n is 0, both Z and Z' are each --CF.sub.2 CF.sub.2 R.sub.f B or when n is 1, at least one of Z and Z' is --CF.sub.2 CF.sub.2 R.sub.f B.

Abstract: Novel derivatives of 3,3'-oxy-bis{[2,2'-di(bromomethyl)]propanoic acid}of formula (1) ##STR1## in which Y represents OR, chlorine or NH--R and wherein R represents hydrogen or an alkyl, aralkyl or aryl group, in which the alkyl, aryl and aralkyl groups are unsubstituted or substituted with 1 to 5 bromine atoms, are described.The novel derivatives of the invention have improved thermal properties and a high content of bromine, and are particularly suitable as flame-retardant agents. Methods of preparation of these novel compounds are described.

Abstract: A process for synthesizing ethers of alkyl alpha(hydroxymethyl)-acrylate by reacting alkyl acrylate and formaldehyde in the presence of a DABCO catalyst. The ethers may be used as cross-linking agents for thermoplastic polymers. Further, these ethers in turn enable synthesis of cyclopolymers that may show promising biological activity.

Abstract: There is disclosed herein improved processes for the preparation of mixtures of alkali metal salts of 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylate and alkali metal salts of 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylate wherein D,L-tartaric acid is employed and recovered by lowering the pH of the reaction medium to within the range of from about 7 to about 9.5. At the reduced pH calcium D,L-tartrate precipitates and is easily separated. The recovered tartrate may be recycled to the synthesis reaction to prepare further product.

Abstract: A process for preparing water-scale inhibitors and, more specifically, a neat process for preparing acrylic acid/ethylene glycol graft co-polymers and a method for their use as scale inhibitors.

Abstract: A halogen-containing polyether comprising repeating units of the formula:--(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.2 --(CHClCF.sub.2 CF.sub.2 O).sub.b --(CCl.sub.2 CF.sub.2 CF.sub.2 O).sub.c --(CHFCF.sub.2 CF.sub.2 O).sub.d --(CFClCF.sub.2 CF.sub.2 O).sub.e --(CF.sub.2 CF.sub.2 CF.sub.2 O).sub.f --(I)wherein a, b, c, d, e and f are each an integer not less than 0 and satisfy the following equations:2.ltoreq.a+b+c+d+e+f.ltoreq.200and1.ltoreq.a+c+d+f,which may be prepared by ring-opening polymerizing 2,2,3,3-tetrafluorooxetane in the presence of an polymerization initiator to give a polyether comprising repeating units of the formula:--(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.a -- (II)wherein a is the same as defined above, and optionally fluorinating and/or chlorinating the polyether (II).

Abstract: Described are anionic surfactants which are made by (1) reacting maleic acid, fumaric acid, itaconic acid or mixtures thereof with at least one selected epoxy-capped poly(oxyalkylated) alcohol in the presence of a peroxy-type free radical initiator to form a carboxylic acid group-containing addition product and (2) neutralizing said addition product with a sufficient amount of a neutralizing agent to convert at least a major proportion of said carboxylic acid groups to salt groups. These surfactants exhibit excellent surface activity as well as being highly soluble in caustic solutions.

Abstract: High yields of 2,2'-oxodisuccinate are secured by reacting maleate and malate in aqueous alkaline media containing mixtures of particular divalent (e.g., Ca.sup.2+) and solubilizing monovalent (e.g., Na.sup.+) cations. In a preferred embodiment, the process has both an elevated temperature primary reaction step and one or more low temperature maturation steps. Yields of 2,2'-oxodisuccinate are increased and formation of fumarate byproduct is minimized.

Abstract: Perfluoropolyethers containing an approximate equal number of difluoromethylene and tetrafluoroethylene repeat units distributed either randomly or in alternating sequence along the polymer chain are disclosed. The polymers range in molecular weight from 500-200,000 amu; the lower molecular polymers being fluid and the intermediate and high molecular weight polymers being solid. The perfluorinated copolymers are synthesized by direct fluorination of corresponding methylene oxide/ethylene oxide copolymers.

Abstract: One-step process for preparing anhydrous, organic acid alkali or alkaline earth metal salts by contacting and reacting an organic or polymeric acid fluoride, anhydride or ester and an organic alkali or alkaline earth metal silanolate.

Abstract: Novel ether carboxylates of the following formula (I) ##STR1## in which R represents a linear or branched alkyl or alkenyl group having from 4 to 32 carbon atoms, and A and B independently represent hydrogen or a --CH.sub.2 COOM group wherein M represents hydrogen, alkali metal, ammonium, alkanolammonium or lower alkylammonium, provided that A and B are not hydrogen at the same time are prepared by a simple reaction in which a monohaloacetic acid or a salt thereof is reacted with a mono and/or dialcoholate of an alkyl glyceryl ether of the general formula (II) ##STR2## in which R has the same meaning as defined above. Optionally, the resulting product may be converted into a free acid or a salt thereof.Highly pure ether carboxylates can be produced from inexpensive and readily available starting materials with high yield. The carboxylates are useful as a surfactant of low stimulus and have wide utility in the fields of cosmetics, detergents, medicines, paints and so on.

Abstract: Ether hydroxypolycarboxylates prepared from epoxysuccinates by treatment with an alkaline calcium compound are disclosed. These compounds act as sequestering agents and are useful as detergency builders. Detergent compositions incorporating the ether hydroxypolycarboxylates can be prepared without use of detergent builder components containing phosphorus or nitrogen.

Abstract: Products which are useful as detergent builders and which do not contain nitrogen or phosphorous atoms are described. Such detergent builders comprise one or more compounds of the Formula I-V below:[MOOCCH.sub.2 (MOOC)CHOCH.sub.2 ].sub.2 CHOCH(COOM)CH.sub.2 COOM (I)HOCH.sub.2 CH(OH)CH.sub.2 OCH(COOM)CH.sub.2 COOM; (II)HOCH.sub.2 CH[OCH(COOM)CH.sub.2 COOM]CH.sub.2 OCH(COOM)CH.sub.2 COOM; (III)MOOCCH.sub.2 (MOOC)CHOCH.sub.2 CH(OH)CH.sub.2 OCH(COOM)CH.sub.2 COOM; (IV)orHOCH.sub.2 CH[OCH(COOM)CH.sub.2 COOM]CH.sub.2 OH (V)wherein M is a salt-forming cation or hydrogen or mixtures thereof. Such compounds and/or mixtures thereof are produced by reacting glycerin with maleic acid (or a source thereof) in the presence of an alkaline earth metal hydroxide.

Abstract: Novel salts of alkenylsuccinic monoesters represented by the following formulas (I) or (II): ##STR1## in which R.sub.1 represents a hydrocarbon group, R.sub.2 represents a hydrogen atom or a methyl group, A represents an alkylene group having from 2 to 4 carbon atoms, B represents a carbonyl group or a methylene group, M is a monovalent or divalent cation.The monoesters can be emulsion-polymerized under optimum conditions while varying the hydrophilic and oleophilic balance depending on the type of monomer because they have hydrophobic hydrocarbon groups and oleophilic carboxylate groups and ether bonds of polyalkyleneoxy groups.The compounds according to the invention are an excellent reactive surface active agent, and also useful as an improver or modifier for polymer because they can impart hydrophilicity to hydrophobic resins when they are used in larger amounts as in the case of reactive surface active agents employed for ordinary.

Abstract: Novel ether carboxylates prepared from ketomalonate esters and diene compounds are disclosed. Detergent compositions incorporating the ether carboxylates can be prepared without use of phosphorus-containing detergent builder materials.

Abstract: Described are anionic surfactants which are made by (1) reacting maleic acid, fumaric acid, or mixtures thereof with at least one selected poly(oxyalkylated) alcohol in the presence of a peroxy-type free radical initiator to form a carboxylic acid group-containing addition product and (2) sulfating said addition product with a sufficient amount of a sulfating agent (i.e. sulfamic acid) to convert at least a major proportion of the terminal hydroxyl groups to sulfate groups. These surfactants exhibit excellent surface activity as well as being highly soluble in caustic solutions.

Abstract: Described are anionic surfactants which are made by (1) reacting maleic acid or fumaric acid, or mixtures thereof with at least one selected poly(oxyalkylated) alcohol in the presence of a peroxy-type free radical initiator to form a carboxylic acid group-containing addition product and (2) neutralizing said addition product with a sufficient amount of a neutralizing agent to convert at least a major proportion of said carboxylic acid groups to salt groups. These surfactants exhibit excellent surface activity as well as being highly soluble in caustic solutions.

Abstract: The present invention describes compounds of the formula:A. MOOCCH.sub.2 (MOOC)HCOCH.sub.2 CH(OH)CH.sub.2 OCH(COOM)CH.sub.2 COOMB. HOCH.sub.2 HC(OH)CH.sub.2 OCH(COOM)CH.sub.2 COOMC. HOCH.sub.2 CH[OCH(COOM)CH.sub.2 COOM]CH.sub.2 OCH(COOM)CH.sub.2 COOM andD. And mixtures thereof where M is a salt-forming cation or hydrogen or mixtures thereof.This invention also discloses products prepared by the process of reacting glycerine and a source of maleic acid in the presence of an alkaline earth metal hydroxide.

Abstract: Certain new halogenated geminal diester compounds are described. The products are useful as broad spectrum antimicrobials.

Abstract: Vinyl ether monomers derived from diesters of the formula: ##STR1## wherein R is CH.sub.3 or C.sub.2 H.sub.5 and n is 0 to 10; copolymers of the vinyl ether monomers with one or more selected perfluorinated monoolefins; articles of manufacture made from the copolymers; process for making the diesters; process for using copolymer membranes in a chlor-alkali cell.

Abstract: Purified hexafluoropropylene oxide is produced by scrubbing to remove impurities that inhibit polymerization of hexafluoropropylene oxide, thus permitting the preparation of polymers having a degree of polymerization of more than 200, including end-capped and chain-extended derivatives thereof.

Abstract: Diesters of the formula: ##STR1## wherein R is CH.sub.3 or C.sub.2 H.sub.5 and n is 0 to 10; vinyl ether monomers derived therefrom; copolymers of the vinyl ether monomers with one or more selected perfluorinated monoolefins; articles of manufacture made from the copolymers; process for making the diesters; process for using copolymer membranes in a chlor-alkali cell.

Abstract: The invention relates to polyethers having an an average molecule weight of 3000 to 5000 and having a propylene oxide proportion of 60 to 80% and an ethylene oxide proportion of 20 to 40%. Also included in the invention are compositions containing said polyethers and methods for the use of said polyethers and compositions, particularly for their anti-lipidaemic effect.

Abstract: The reaction of a polyfluorocarbonyl compound such as a polyfluoroketone or polyfluorocarboxylic acid fluoride with fluoride ion and a polyfluoroallyl chloride, bromide or fluorosulfate produces a polyfluoroallyloxy carboxylic acid or ester, e.g., CF.sub.2 .dbd.CFCF.sub.2 OCF.sub.2 CF.sub.2 COOH. The polyfluoroallyloxy compounds copolymerize with ethylenically unsaturated monomers such as tetrafluoroethylene, chlorotrifluoroethylene or vinylidene fluoride to form polymers which are moldable, and in some cases electrically conducting or are water-wettable and dyeable.

Abstract: Disclosed herein are detergent compositions containing a water soluble organic surfactant and as a builder therefor a compound of the general formulas ##STR1## wherein X and X' are selected from the group consisting of hydrogen, alkyls having from 1 to 4 carbon atoms, alkoxys having from 1 to 4 carbon atoms, alkoxyalkyls having from 1 to 4 carbon atoms, hydroxyalkyls having from 1 to 4 carbon atoms, carboxyl in salt form (i.e., --COOH), and carboxymethyloxy in salt form (i.e., --OCH.sub.2 COOH), with the provision that only one of X and X' can be hydrogen, alkoxy, alkoxyalkyl, hydroxyalkyl, carboxyl in salt form or carboxymethyloxy in salt form; Y and Y' are selected from the group consisting of hydrogen, alkyls having from 1 to 2 carbon atoms, and hydroxyalkyls having from 1 to 4 carbon atoms; in the cases where both X and Y' or X' and Y are hydrogen or alkyls, X' and Y or X and Y' taken together can constitute a single bond which connects the .alpha. and .alpha.

Abstract: Carboxymethyloxysuccinic acid of improved purity may be prepared from its calcium salt by first precipitating the calcium as calcium carbonate by reaction with sodium carbonate, removing the calcium carbonate, acidifving the resulting solution of the sodium salt with sulfuric acid, extracting the free acid with a C.sub.4 or C.sub.5 alcohol or cyclohexanol and recovering the purified acid from the alcohol extracts.

Abstract: Compounds having the formula ##STR1## wherein M is an alkali metal or ammonium, R.sub.1 and R.sub.2 are hydrogen, methyl or ethyl and R.sub.3 is hydrogen, methyl, ethyl or COOM are useful sequestrants and detergency builders. Lower alkyl esters and acids of such compounds are useful intermediates for their production.

Abstract: Ether carboxylates represented by the formula: ##STR1## wherein R.sup.1 and R.sup.2 are individually selected from the group consisting of alkyl containing up to 20 carbon atoms, and M.sup.1, M.sup.2 and M.sup.3 are individually selected from the group consisting of alkyl containing up to about 4 carbon atoms, are useful as intermediates to prepare the corresponding acid or alkali metal, ammonium and alkanol amine salts, which are useful as chelants, sequestrants and detergent builders.

Abstract: Novel ethercarboxylic acids and their salts containing at least two carboxylic acids and at least one glycolic acid ether, useful as sequestering agents for alkaline earth metal ions, as well as a process for their preparation.

Abstract: Copolymers of acetal carboxylates are provided which have the following empirical formula ##STR1## where Y is one or more comonomers randomly distributed in the copolymer; the product of n and q averages at least 4; p is at least 1; and M is selected from the group consisting of alkali metal, ammonium, alkyl groups having 1 to about 4 carbon atoms, and alkanol ammonium groups having 1 to about 4 carbon atoms in the alkyl chain. Such copolymers are useful as detergent builders to replace sodium tripolyphosphate (STP) in detergent formulations. The copolymers are stable under laundry use conditions, but depolymerize in acid media, making the fragments more readily biodegradable in waste streams.

Abstract: Ether carboxylates represented by the formula: ##STR1## wherein R.sub.1 and R.sub.2 are individually selected from the group consisting of alkyl containing up to 20 carbon atoms and M.sub.1 and M.sub.2 are individually selected from the group consisting of alkyl containing up to about 4 carbon atoms, are useful as intermediates to prepare the corresponding acid or alkali metal, ammonium and alkanol amine salts, which are useful as chelants, sequestrants and detergent builders.

Abstract: This disclosure concerns:(a) Compounds having the molecular structure represented by the formula: ##STR1## wherein M is selected from the group consisting of --H, --CH.sub.3, --C.sub.2 H.sub.5, --NH.sub.4, --Na, --K and combinations thereof; R is selected from the group consisting of an alkyl radical (branched or straight chain) containing up to about C.sub.20, --CH(CO.sub.2 M).sub.2, and --CH.sub.2 CO.sub.2 M, and R' is selected from the group consisting of an alkyl radical (branched or straight chain) containing up to about C.sub.20, --H, and --OR;(b) a method for making the compounds of (a);(c) solid and liquid detergent compositions comprising compounds of (a), and(d) washing processes employing the compounds of (a) and/or the compositions of (c).

Abstract: A machine dishwashing composition is provided which comprises the following: (a) from 5 to 90 percent by weight of a compound corresponding to the formula ##STR1## wherein M is alkali metal or ammonium and wherein n is a number from 1 through 3, and wherein R is selected from an alkyl radical having from 1 to 20 carbon atoms, an alkenyl radical having from 1 to 20 carbon atoms, an alkynyl radical having from 1 to 20 carbon atoms, a cycloalkane radical having from 3 to 20 carbon atoms, an alkanol radical having from 2 to 20 carbon atoms, an ether radical having at least 3 carbon atoms, an aryl radical having at least 6 carbon atoms, a substituted aryl radical having at least 6 carbon atoms wherein the substituents are halogen, nitro, amide or carboxyalkyl substituents, aralkyl radicals having at least 7 carbon atoms and arylether radicals having at least 7 carbon atoms, and (b) from 0 to 5 percent by weight of a low-foaming anionic or nonionic surfactant, (c) a chlorine-providing material in an amount sufficie

Abstract: Detergent compositions containing self-requestering surfactants the molecules of which contain both a hydrophilic structure and a lipophilic structure are disclosed. The compositions comprise at least 5% by weight, of hydrosoluble salts having the formula ##STR1## in which R is alkyl, arylalkyl or alkylaryl of from 6 to 18 carbon atoms;at least one of the groups represented by Z is a --CH.sub.2 --COO.sup.- Me.sup.+ carboxymethylene group in which Me.sup.+ represents an ion selected from sodium, potassium and ammonium ions and from quaternary onium cations, and combinations thereof, and the remaining Z groups, which may be the same or different, represent H or a carboxymethylene as defined above.

Abstract: Copolymers of keto dicarboxylates are provided which have the following general formula ##STR1## WHERE Y is one or more comonomers; n averages at least 2; p is at least 1; and M is selected from the group consisting of alkali metal, ammonium, alkyl groups having 1 to about 4 carbon atoms, and alkanol amine groups having 1 to about 4 carbon atoms in the alkyl chain. Such copolymers are useful as detergent builders to replace sodium tripolyphosphate (STP) in detergent formulations. The copolymers are stable under laundry use conditions, but depolymerize in acid media, making the fragments more readily biodegradable in waste streams.

Abstract: Diglycolic acid is separated from glycolic acid by preferential extraction from an aqueous mixture of the two acids using an organic solution of a water-insoluble trihydrocarbylphosphine oxide as the extraction agent.

Abstract: There are disclosed herein novel builder salts of alkyloxysuccinic acids, alkyloxyhydroxysuccinic acids, alkylthiosuccinic acids, alkylthiohydroxysuccinic acids, and the sulfoxide and sulfone derivatives of the alkylthiosuccinic and alkylthiohydroxysuccinic acids. The new builder compounds can be generally represented as follows: ##STR1## wherein Z is selected from the group consisting of O, S, SO and SO.sub.2 ; X is H or OH; R is an alkyl radical containing from 6 to 30 carbon atoms and M is selected from the group consisting of alkali metal cations, ammonium and substituted ammonium. These new builder compounds can be substituted in detergent compositions for existing builders containing phosphorous or nitrogen without impairing and in some cases improving the efficiency of such detergent compositions.

Abstract: Novel polyfunctional compounds which may be hydrolyzed to the corresponding salts, which in turn are metal sequestering agents, are disclosed, as well as a novel method for their preparation. The compounds are the reaction product obtained from the reaction of selected salts of monoalkyl esters of maleic acid with selected active hydrogen containing compounds. These products are prepared by a reaction of the starting materials in preferably a substantially anhydrous medium at an elevated temperature.

Abstract: It is disclosed that high purity alkali metal salts of carboxyalkoxy succinic acid are produced from maleic acid and a hydroxy organic acid by reaction of zinc or alkaline earth metal salts of said acids to form a zinc or alkaline earth metal carboxyalkoxy succinate, by reacting the zinc or alkaline earth metal carboxyalkoxy succinate with an alkali metal carbonate in a stoichiometric deficiency of carbonate to selectively react with the alkaline earth metal carboxyalkoxy succinate, leaving the impurities as insoluble alkaline earth metal salts, removing the zinc or alkaline earth metal as insoluble carbonate, and recovering an alkali metal carboxyalkoxy succinate solution which is then evaporated to dryness.

Abstract: An improved method for the conversion of an alkaline earth metal carboxymethyloxysuccinate to a trialkali metal carboxymethyloxysuccinate is disclosed wherein a mixture of alkali metal carbonates and bicarbonates are utilized to precipitate the alkaline earth metal as an insoluble carbonate. The amount of alkali metal carbonate/bicarbonate mixture utilized corresponds to a 1-6% molar excess over the number of moles of alkaline earth metal ion present. The pH of the reaction medium during precipitation is maintained in the range of about 10 to 11.5, preferably 10.6 to 11.0, and the temperature, between 80.degree. and 100.degree. C., preferably 90.degree.-100.degree. C. After separation of the insoluble alkaline earth carbonate, there is obtained a solution of the trialkali metal carboxymethyloxysuccinate containing a low calcium level, namely less than about 0.2% basis the percent of trialkali metal carboxymethyloxysuccinate present.