Synergistic composition

Abstract

A synergistic composition comprising a THP salt and a biopenetrant, in which the biopenetrant comprises a polymer of an unsaturated carboxylic acid or a copolymer of an unsaturated carboxylic acid with a sulphonic acid, said polymer or copolymer being terminated by a mono- or diphosphonated unsaturated carboxylic acid group or having such monomers incorporated into the polymer backbone. This composition acts synergistically to enhance the biocidal efficacy of the THP salt against both planktonic (free-swimming) and sessile (attached) bacteria, and also acts synergistically to enhance the efficacy of the THP salt in the dissolution of iron sulphide scale.

1 .- 20 . (canceled) 
     
     
         21 . A synergistic composition comprising: (i) a THP salt and (ii) a biopenetrant, wherein the biopenetrant comprises a polymer of an unsaturated carboxylic acid or a copolymer of an unsaturated carboxylic acid with a sulphonic acid, said polymer or copolymer being terminated by a mono- or di-phosphonated unsaturated carboxylic acid group or having such monomers incorporated into the polymer backbone. 
     
     
         22 . A composition according to  claim 21 , wherein the THP salt is tetrakis(hydroxymethyl) phosphonium sulphate. 
     
     
         23 . A composition according to  claim 21 , wherein the THP salt is tetrakis (hydroxymethyl) phosphonium phosphite, bromide, fluoride, chloride, phosphate, carbonate, acetate, formate, citrate, borate or silicate. 
     
     
         24 . A composition according to  claim 21 , wherein the biopenetrant comprises a polymer of an unsaturated carboxylic acid or a copolymer of an unsaturated carboxylic acid with a sulphonic acid, said polymer or copolymer being either terminated by vinyiphosphonic acid (VPA) or vinylidene-1,1-diphosphonic acid (VDPA) or having such monomers incorporated into the polymer backbone. 
     
     
         25 . A composition according to  claim 21 , wherein the polymer or copolymer of the biopenetrant is a polyacrylate or an acrylate/sulphonate copolymer. 
     
     
         26 . A composition according to  claim 25 , wherein the biopenetrant is a VPA end-capped polymer or a VDPA end-capped polymer or a polyacrylate incorporating VPA and/or VDPA monomers. 
     
     
         27 . A composition according to  claim 25 , wherein the biopenetrant is a VDPA end-capped copolymer or a VPA end-capped copolymer or an acrylate/sulphonate copolymer incorporating VPA and/or VDPA monomers. 
     
     
         28 . A composition according to  claim 26 , wherein the proportion of the VPA or VDPA polymer or copolymer to THP salt is from 1 to 50% by weight. 
     
     
         29 . A composition according to  claim 28 , wherein the proportion is from 1 to 25% by weight. 
     
     
         30 . A composition according to  claim 29 , wherein the proportion is from 1 to 5% by weight. 
     
     
         31 . A method of treating a water system contaminated, or liable to contamination, with microbes such as bacteria, fungi or algae, comprising the step of adding to said system separately or together, a biocidally active amount of a THP salt and a biopenetrant, wherein the biopenetrant comprises a polymer of an unsaturated carboxylic acid or a copolymer of an unsaturated carboxylic acid with a sulphonic acid, said polymer or copolymer being terminated by a mono- or di-phosphonated unsaturated carboxylic acid group or being a random copolymer containing a mono or di-phosphonated unsaturated carboxylic acid, thereby killing at least some of said microbes. 
     
     
         32 . A method of treating a water system containing or in contact with an metal sulphide scale, comprising the step of adding to said system separately or together, a THP salt and a biopenetrant, wherein the biopenetrant comprises a polymer of an unsaturated carboxylic acid or a copolymer of an unsaturated carboxylic acid with a sulphonic acid, said polymer or copolymer being terminated by a mono- or di-phosphonated unsaturated carboxylic acid group or being a random copolymer containing a mono or di-phosphonated unsaturated carboxylic acid, wherein the THP salt and the biopenetrant are present in a synergistically effective amount, and thereby dissolving at least part of said scale. 
     
     
         33 . The method of  claim 32 , wherein the scale is iron sulphide scale.