Phosphino derivatives
AssigneeAlbright & Wilson UK Limited
InventorsKeith Philip Davis, Alan Craig Smith, David Robert Edward Walker, Gary Woodward
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Abstract
The reaction of compounds of the formula: X.sub.2 O.sub.3 P CHY CZ.sub.2 where Y and each Z are each H, PO.sub.3 X.sub.2, SO.sub.3 X or CO.sub.2 X (e.g. vinyl phosphonic acid or vinylidene diphosphonic acid) with hypophosphorous acid in the presence of free radicals provides novel compounds X.sub.2 O.sub.3 PCHYCZ.sub.2 PO.sub.2 XH which react with monomers such as vinyl sulphonate, vinyl phosphonate, vinylidene diphosphonate and acrylic acid to form telomers useful for scale inhibition, especially barium scale in oil wells. The polymers show better absorption to rock than PVSA and better thermal stability than random copolymers containing equivalent phosphorus.
Claims31
A composition having the formula:
- X.sub.2 O.sub.3 P.CHYCZ.sub.2 PO.sub.2 XR (I)
- where X is selected from the group consisting of H, alkali metal, alkaline earth or other polyvalent metal, ammonium and organic bases capable of forming a water-soluble salt of said compound, and R is selected from the group consisting of hydrogen, a diphosphonoethyl group and a homo- or co- polymeric chain comprising between 1 and 100,000 groups, said groups being derived from at least one unsaturated compound in which the multiple bond is activated chemically by an adjacent electron withdrawing group, and Y and each Z are individually selected from the group consisting of hydrogen, a PO.sub.3 X.sub.2, SO.sub.3 X, CO.sub.2 X, an alkyl moiety and an aryl moiety.
Dependencies are inferred from the claim text.