Ciba-Geigy Corporation

Ciba Geigy (UK) Limited

Michael A Finan

Peter Miles

Norman Richardson

Malcolm John Smith

Colin D Campbell

Alan Marshall

David R Clark

Kenneth W Shelton

Michael J Lees

Geoffrey Graham

Donald K Howard

Thomas I Jones

The invention provides particulate calcium carbonate having incorporated therein from 0.1 to 10% by weight, based on the weight of calcium carbonate, of polymaleic acid or a water-soluble salt thereof.

Particulate calcium carbonate

Aqueous compositions containing compounds having the formula: ##STR1## wherein R is a straight- or branched alkyl residue containing 11 to 17 carbon atoms and X and Y are the same or different and each is an alkali metal, an alkaline earth metal, ammonium, an amine radical or hydrogen for selectively flocculating iron ions.

Treatment of aqueous systems

A method of inhibiting scale formation by salts of calcium, magnesium, barium and strontium from aqueous solutions, by adding to the aqueous solution a minor proportion of a product comprising a telomer of formula I: ##STR1## or a salt thereof, wherein X is CO.sub.2 H when Y is H and vice versa, B and B' are each hydrogen or B is CH.sub.3 when B' is H or vice versa, m is an integer from 2 to 100 and n is 0 or 1, R is alkyl having 1 to 22 carbon atoms substituted by one or more hydroxy groups.

Novel compositions of matter for use in the treatment of aqueous systems

A method of inhibiting the precipitation of scale-forming salts of calcium, magnesium, barium and strontium from aqueous systems which involves adding to the aqueous system a telomeric compound of the formula: ##STR1## and the salt forming derivatives thereof, wherein: R.sup.11 is H, CH.sub.3, C.sub.2 H.sub.5 ; R.sup.1 is --OX wherein X is alkyl of 1-4 carbon atoms or hydrogen; R is hydrogen, alkyl of 1-18 carbon atoms, cycloalkyl of 5-12 carbon atoms, phenyl or benzyl, and n is a positive integer of at most 100.

A method of inhibiting the precipitation of the scale forming salts of calcium, magnesium, barium and strontium from aqueous systems comprising adding to the aqueous system a minor proportion of a product comprising a telomeric compound of the formula: ##STR1## or salts thereof, wherein R.sup.11 is hydrogen or a methyl or ethyl residue and n is a positive integer of at most 100, R is hydroxyl and R.sup.1 is hydroxyl.

A process for the prevention of scale and the inhibition of corrosion which comprises adding to water a hydrolyzed terpolymer of maleic anhydride with vinyl acetate and ethyl acrylate, the molar ratio of maleic anhydride to the other monomers being from 2.5:1 to 5:1, the ratio of vinyl acetate to ethyl acrylate being 1:1 to 2:1, and the molecular weight of the terpolymer being below 1000.

Treatment of water

A method of inhibiting scale formation by salts of calcium, magnesium, barium and strontium from aqueous solutions, by adding to the aqueous solution a minor proportion of a product comprising a telomer of formula I: ##STR1## or a salt thereof, wherein X is CO.sub.2 H when Y is H and vice versa, B and B' are each hydrogen or B is CH.sub.3 when B' is H or vice versa, m is an integer from 2 to 100 and n is 0 or 1, R is an hydroxyl group, alkyl having from 1-22 carbon atoms substituted by one or more carboxyl groups.

A method of inhibiting the precipitation of the scale forming salts of calcium, magnesium, barium and strontium from aqueous systems comprising adding to the aqueous system a minor proportion of a product comprising a telomeric compound of the formula: ##STR1## or salts thereof, wherein R.sup.11 is hydrogen or a methyl or ethyl residue and n is a positive integer of at most 100, R is a residue --OX wherein X is a straight or branched alkyl residue having from 1 to 4 carbon atoms, and R.sup.1 is a residue --OX wherein X has its previous significance.

Oxo-polycarboxylic acids act as set control agents, preferably as set retarders for plasters. Examples of usable acids are 2,2,6,6-tetra(.beta.-carboxyethyl)cyclohexanone, 2,2-di(.beta.-carboxyethyl)-3,5,5-trimethylcyclohexanone or 3-acetyl-3(.beta.-carboxyethyl)-pimelic acid. Also the salts of these acids are usable. The set control agents are added to the plaster in amounts of 5 to 5000 ppm.

Plaster compositions containing oxo-polycarboxylic acids as a set

A method of inhibiting the precipitation of scale-forming salts of calcium, magnesium, barium and strontium from aqueous systems comprising adding to the aqueous system a telomeric compound of the formula: ##STR1## or salts thereof, wherein R.sup.11 is hydrogen, methyl or ethyl, R is hydrogen, 1-18C alkyl, 5-12C cycloalkyl, aryl, aralkyl, a residue of formula: ##STR2## wherein R.sup.11 has its previous significance and the sum of n + m is an integer of at most 100, or a residue --OX wherein X is hydrogen or 1-4C alkyl, and R.sup.1 is a residue --OX wherein X has its previous significance.

Growing community of inventors

Macclesfield, United Kingdom

Michael A Finan