Phosphonic acid polymers
AssigneeAlbright & Wilson UK Limited
InventorsMohsen Zakikhani, David Robert Edward Walker, Peter David Hasling, Alan Craig Smith, Keith Philip Davis
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Abstract
Phosphonic acid polymers are prepared from di- or polyphosphonic acids having one or more unsaturated C.dbd.C bonds (e.g. vinylidene-1,1-diphosphonic acid), either as homopolymers or as higher polymers with at least one further compound having unsaturated C.dbd.C bonds (e.g. acrylic acid). The polymers can be used as, or in connection with, flame-retardants, corrosion inhibitors, coatings, cements and ion exchange resins.
Claims25
A method for the treatment of an aqueous liquid containing at least 200 ppm total hardness expressed as calcium carbonate, and having a maximum pH of 8.5 to inhibit the formation of insoluble divalent or trivalent metal salts in said liquid, wherein said method comprises adding to said liquid an effective amount of up to 100 ppm of said liquid of a polymer selected from the group consisting of:
- (a) homopolymers of di-phosphonic acids or of fully or partly neutralised salts of said acids containing at least one unsaturated carbon-to-carbon bond;
- (b) co-polymers of di-phosphonic acids or of fully or partly neutralised salts of said acids containing at least one unsaturated carbon-to-carbon bond and a further compound containing at least one unsaturated carbon-to-carbon bond;
- and
- (c) terpolymers of di-phosphonic acids, or of fully or partly neutralised salts of said acids, containing at least one unsaturated carbon-to-carbon bond and two further compounds, each of said two further compounds containing at least one unsaturated carbon-to-carbon bond.
Dependencies are inferred from the claim text.