MXPA00006320A - Biocidal compositions and treatments - Google Patents

Abstract

A synergistic biocide comprises a tris(hydroxymethyl)phosphine or a tetrakis (hydroxymethyl)phosphonium salt and at least one non-surfactant biopenetrant, such as a polymer or copolymer having a plurality of quaternary ammonium groups, a hydrotrope or a syntan, together optionally with a surfactant.

Description

BIOCIDAL COMPOSITIONS AND TREATMENTS The present invention relates to synergistic biocidal mixtures of hydroxymethyl phosphonium insecticides with certain non-foaming biopenetrants. GB 2 145 708 describes biocidal uses of titanium (hydroxymethyl) phosphonium ester salts, which together with their original base, tris (hydroxymethyl) phosphine, are collectively referred to herein as "THP". US 4 778 813 describes the biocidal use of quaternary ammonium polymers. GB 2 178 960 describes synergism between THP and the surfactant. GB 2 228 680 describes synergism between THP and certain aldehydes. EP 0 385 676 describes compositions comprising THP, a synergistic amount of a thiocyanate insecticide and a glycol ether as a solvent for the latter. US 3 644 083 describes the use of THP with nitrogenous organic compounds as flame retardants. GB 2 257 043 describes the application of THP to wood in conjunction with quaternary surfactants to control sapstain. THP formulations are increasingly widely used for water treatment, for treating cooling water, processing water, for example, in paper and pulp manufacturing, drilling fluids and other aerobic water systems, as well as in anaerobic systems such as oil formation water, injection water, water produced and water used in hydrostatic testing. Advantages include fast and effective bactericidal activity and environmental acceptability. Particularly, in systems where silt-forming bacteria proliferate (for example, in aerobic systems such as cooling water) it has been found desirable to use THP formulations containing synergistic amounts of a surfactant according to GB 2 178 960, with object of improving the effective biocidal action in cost. It is believed that the surfactant helps the penetration of biomass by THP. However, such formulations cause foaming problems. Attempts to combine THP with other insecticides (eg, aldehydes), which do not cause foaming, have not been able to provide such effective biocidal action against the bacteria that form silt, and / or have departed from the favorable environmental profile of THP. We have now discovered that combinations of THP with certain biopenetrants and non-surfactants provide strongly synergistic biocidal formulations that give excellent penetration of bacterial silt and enhanced activity against planktonic bacteria without causing excessive foam. We have also discovered that mixtures of THP with a surfactant, and with a biopenetrant non-surfactant gives a marked ternary synergism, allowing improved biocidal efficiency with reduced foaming. Our invention provides a biocidally synergistic mixture comprising THP and at least one synergistic biopenetrant product, no surface active agent, compatible with THP together with optionally a surfactant, characterized in that the biopenetrant non-surfactant is selected from copolymers and quaternary ammonium polymers, a naphthalene alkyl or benzene alkyl sulfonate having less than 5 aliphatic carbon atoms and / or a phosphono polycarboxylic acid. According to a second embodiment, the invention provides a method for treating aqueous systems contaminated, or exposed to contamination, with microbes such as bacteria, fungi or algae, which comprises applying thereto separately or together, a biocidally active amount of the components of a synergistic mixture of THP with either a biopenetrant or non-surfactant agent such as the above or a syntan. The aqueous system can, for example, be contaminated with bacterial silt and / or planktonic bacteria. The invention is of use to treat aerobic systems such as cooling towers and also for anaerobic systems, such as oil wells, for example., during secondary recovery. THP is conveniently presented in the formulation as a salt, but is preferably used at a pH sufficient to form the base. The salt is preferably sulfate, chloride or phosphate. However, any water-soluble salt can be used including phosphite, bromide, fluoride, carbonate, acetate, formate, citrate, borate or silicate. In fact, any counter ion that is chemically compatible with THP can be used, the main criterion being its economic selection. The oxidation of THP to tris (hydroxymethyl) phosphine oxide (THPO) should be avoided and the oxidizing agents for THP are preferably substantially absent. The composition may contain oxygen scavengers to minimize oxidation by atmospheric oxygen. The pH of the composition can be below 3.5 to avoid the formation of THPO during storage but the pH in addition to aqueous systems is preferably between 3.5 and 9 and more preferably less than 8, for example, 4 to 7.5. High alkalinity, for example, above 10 preferably is avoided. The pH of the aqueous system can optionally be adjusted by the addition of alkali or acid as appropriate. An essential component of the invention is a biopenetrant non-surfactant agent. The surfactants are amphiphilic compounds which, even when they occur at low concentrations in water (for example, 0.1% by weight), substantially reduce the interfacial free energy of a water / hydrophobic interface. Surfactants can be identified by their effect on the surface tension of water. Non-surfactants do not appreciably reduce surface tension at low concentrations. Typically, the reduction in surface tension by a non-surface active agent in concentrations in the order of 0.1% does not amount to more than about 5% of the value for pure distilled water. In the same concentrations the typical surfactants would reduce the surface tension by 50% or more. For the purposes of this specification a compound is considered non-surfactant if the surface tension of water decreases by less than 20% at a concentration of 0.1% by weight. Preferably, the reduction is less than 15%, for example less than 10%, especially less than 5%. The biopenetrant non-surfactant may be, for example, a copolymer or quaternary ammonium polymer. The quaternary ammonium polymer can be for example any of those described in US 4 778 813. Particularly preferred is poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dihydrochloride]. That is, a copolymer of NNN'N'-tetramethyl-1,2-diamino ethane with bis (2-chloroethyl) ether, which is referred to herein as "WSCP". The last one is the commercial name of the product used in example 1, which is sold by Buckman Laboratories. However, any other water-soluble polymer containing a plurality of quaternary ammonium groups can be used. Such compounds typically comprise a polymeric cation of the formula: where: each R is a divalent organic group, constituting with the ammonium group a monomeric residue or separately selected from two or more comonomer residues; each R1 is a hydroxyalkyl or alkyl group, typically having from 1 to 4 carbon atoms and preferably methyl or ethyl; X is hydrogen or a monovalent organic or inorganic final cover group; and n is from 2 to 3000, for example 5 to 2000, especially 8 to 1000, for example 10 to 500, more preferably 20 to 100. The counter ion can be any anion compatible with suitable THP, for example, chloride, sulfate, phosphate , bromide, fluoride, carbonate, formate, acetate, citrate, lactate, tartrate, methosulfate, borate or silicate, R can be for example an alkylene Ct-6, oxyalkylene, polyoxyalkylene, haloalkylene, halooxyalkylene, halo polyoxyalkylene or a group R1 R2-Ñ R 3 and R wherein R 2 may be a halopolyoxyalkylene group or halooxyalkylene group, haloalkylene group, polyoxyalkylene group, oxyalkylene group, C 1 e alkylene and R 3 represents a covalent bond or a group R 2. The polymer can be, for example, a polyethylene methylated polyamine of the formula F CH3 NCCI- 2 CH2CH2 N (CH3) 3 n where n is 2 to 10. Some other typical examples include: Poly [hydroxyethylene (dimethyliminium) ethylene (dimethyliminium) methylene dichloride] Hydroxyethylene (dimethyliminium) polymer -hydroxypropylene (dirnethyliminium) methylen] 43- (dimethylammonium) propyl] -? / [3- (ethyleneoxyethylene dimethyl ammonium) propyl] urea -4- [1 -tris (2-hydroxyethyl) ammonium chloride -2-butenyl diclom. ] poly [1-dimethyl-ammonium chloride-2-butenii] tp "s (2-hydroxyethyl) ammonium chloride The biopenetrant non-surfactant may alternatively be a hydrotrope, hydrotropes are sometimes confused with surfactants because Although hydrotropes do not significantly affect surface tension at low concentrations, hydrotropes act as solubilizers.When they are present at relatively high concentrations (eg, greater than about 1%), they increase the solubility in water of solutes. or hardly soluble. An important class of hydrotropes to be used according to our invention comprises the aryl lower alkyl sulfonates. Water soluble salts, for example, sodium, potassium, ammonium or sulfonic acid salts eumeno or sulfonic acid benzene ethyl, xylene sulfonic, toluene sulfonic, benzene sulfonic are very effective. Generally, alkylbenzene sulfonic acids having up to four or even five aliphatic carbon atoms show hydrotropicity but no significant surfactance. Above six aliphatic carbons, for example, sodium benzene octyl sulfonate, surfactance predominates over hydrotropicity. Naphthalene sulfonates are also useful as biopenetrants, non-surfactants, for example, C1-4 alkyl naphthalene sulphonates of alkali metal. Urea is also an effective hydrotrope. An additional category of biopenetrants, non-surfactants, comprises syntans. The latter includes a variety of resins and prepolymers that are used in the tanning industry as an alternative for tannin or chromium. The animal skins comprise a layer of collagen, and the tanning agents react to degrade the reactive sites within the collagen. An effect of this reaction is to increase the minimum temperature, in which the leather tends to shrink in hot water. For the purpose of this specification "sintan" is used to refer to synthetic organic compounds capable of reacting with collagen to cross-link to increase the shrinkage temperature of the leather. For example, the term includes any water-soluble polymer prepared by copolymerizing formaldehyde, which is capable of increasing collagen shrinkage strength and which comprises at least two units of the formula wherein each M is an aryl group such as an anilino, naphthyl or phenyl group substituted with one or more sulfone or sulfonimide, hydroxyl and / or sulfate groups, or a nitrogenous comonomer such as a meiamine, urea or dicyandiamide residue. As used herein the term "syntan" also includes resin syntans which are homopolymers or copolymers of unsaturated carboxylic acids or their salts, esters, amides or nitriles, for example, acrylic acid, methacrylic acid, acrylamide, acrylonitrile, acid maleic, fumaric acid, itaconic acid, aconitic acid, crotonic acid, isocrotonic acid, citraconic acid, mesaconic acid, angelic acid, tíglico acid and cinnamic acid. The copolymers also comprise other vinyl comonomers such as styrene. Also included are condensates of acetone with, for example, sulfones and sulfonamides, and resins based on dicyandiamide. Particularly preferred are: copolymers of sulfonated aryl formaldehyde; THP condensates with nitrogen compounds; maleate or polyacrylate phosphono telomeres such as those described in EP 0 491 391; or ethyl phosphino phosphino telomeres as described in EP 0 861 846. The sulfonated aryl formaldehyde copolymer can be for example sulfonated naphthalene sodium formaldehyde condensate, phenol sodium formaldehyde concentrate, or sodium resorcinol formaldehyde condensate, or a condensate of formaldehyde with a naphthalene sulfonate or sodium alkyl benzene having less than 5 carbon atoms. The THP condensates may contain 2 or more phosphorus atoms, provided that the phosphorus compound is soluble in water at a concentration of at least 0.5 g / l at 25 ° C. Such phosphorus compounds contain a total of at least 2 hydroxymethyl groups, usually at least one per phosphorus atom, and preferably at least 2 hydroxymethyl groups per phosphorus atom. The group (s) which binds to the phosphorus atoms can be of the formula -R-, -RO-, -OR-, -R-NH-R or -RR "-R- where R is an alkylene group of 1 to 4 carbon atoms and R "is the residue formed by the removal of two hydrogen atoms, attached to nitrogen, of a di or polyamide or an amine or di or polyamine, such as urea, a C ^ alkylamine or dicyandiamide, thiourea or guanidine. Such compounds with 2 or more, for example, 3 hydroxyalkyl groups per phosphorus atom can be made by self-condensation of THP salts with a compound of the general formula RnH2 such as urea, or an alkylamine Ci at 20, for example, at Heat at 40 to 120 ° C. The THP condensate can be prepared in situ by adding THP and a minor proportion of (for example) a condensable comonomer such as urea, melamine, an amine or dicyandiamide, simultaneously or consecutively to the system to be treated. Thus, for example, the aryl sulfonate hydrotrope or urea can function as hydrotropes or comonomers for in situ formation of syntans or in both capacities, according to our invention. The phosphono telomer may be a compound of the formula H [CHRCHR] n-PO3M2 wherein at least one R group in each unit is a sulfone or phosphono group, CH2OH, COOM, and the other group r which may be the same as , or different from, the first group R, is hydrogen or a C1-7 alkenyl group or substituted d7 alkyl of sulfate and / or hydroxy, sulfonyl, hydroxyl, COOM and each M is a cation such that the phosphonated oligomer it is soluble in water and n is greater than 1, for example up to 10. It is possible to use cotelomers, for example, of the above formula, but in which the chain [CHRCHR] n contains at least two groups [CHRCHR] derived from different monomers and in which n has a total value of at least 3. For example, we include a phosphonated trimer or high coligomer of maleate and acrylate containing at least one group [CH2 CHCOOM] and at least one group [CHCOOM CHCOOM]. Particularly preferred are the phosphonated oligomers of maleic acid, of the formula H (CHO2M.CHCO2M) nP? 3M3, wherein n is greater than 1 and M is a cationic species such that the compound is soluble in water, and especially mixtures of such compounds with phosphonosuccinic acid or its salts soluble in water. Particularly preferred are mixtures of phosphono succinate salts and an oligomer of the above formula where n = 2, such as can be prepared by reacting sodium phosphite with a small molar excess of sodium maleate in an alkaline aqueous solution, concentrated at elevated temperatures in the presence of a * free radical source such as hydrogen peroxide. Other phosphono telomeres which are useful according to the invention include phosphonoacrylate telomeres, for example of the formula: M2O3PICH2CHCOOM] nH wherein n can be 2 to 60, preferably 3 to 30, for example 4 to 20. 1-phosphino-2-phosphino-ethane can be reacted with salts of telomerisable unsaturated acids such as maleic and acrylic to make syntans which are useful in the present invention.

Other phosphono carboxylates of use include phosphonosuccinates and butane salts of 2-phosphono-1, 2,4-tricarboxy. The biopenetrating synergetic product is usually not present in a concentration of weight greater than THP, although higher concentrations in weight based on THP, for example, up to 10: 1 or even 100: 1 are technically possible but commercially undesirable. The proportion is preferably less than 50% by weight based on the weight of THP, more usually less than 20%, typically less than 10%, especially less than 5%. Although very small amounts can be effective we prefer to use proportions of biopenetrant greater than 0.1% based on the weight of THP, usually greater than 0.5%, especially greater than 1%. The insecticide is typically supplied as an aqueous THP solution at 10 to 75%, for example 20 to 60%, especially 30 to 50% by weight containing 0.1 to 10%, for example 0.2 to 5%, especially 0.5 to 2. % of the synergistic product, based on the total weight of the solution. Alternatively, the composition can be supplied as a solid formed by coating THP on, or absorbing it in, a porous or granular or powdery acid substrate such as adipic acid. The mixture is typically used in a dose of 1 to 1500 ppm by weight of THP based on the weight of water to be treated, usually 2 to 500, especially 5 to 250, for example 10 to 150. According to a particular modality it has been It has been found that the mixtures of the aforementioned biopenetrating synergetic products with surfactants and THP salts provide an increased synergism. Such mixtures can provide even more effective biocidal activity, at substantially lower levels of both insecticide and surfactant than those required for conventional mixtures of THP salts and surfactant. Our invention in accordance with the above further provides a biocidally synergistic mixture comprising: (A) THP; (B) at least one biopenetrant non-surfactant as mentioned above; and (C) surfactant. The invention further provides a method for treating water with a biocidally active amount of said synergistic mixture. The surfactants for use in our invention typically contain hydrophobic groups such as alkenyl, cycloalkenyl, alkyl, cycloalkyl, aryl, alkyl / aryl or more complex aryl residues (as in petroleum sulfonates) having from 8 to 22, preferably 10 to 20, typically 12 to 18 carbon atoms and a hydrophilic residue. Other hydrophobic groups included in the invention are the polysiloxane groups. The surfactant may, for example, consist substantially of at least a slightly water-soluble salt of monoesterified or sulphonic sulfuric acid, for example, an alkylbenzene sulphonate, alkyl sulfate, alkyl ether sulfate, olefin sulfonate, alkane sulfonate, alkylphenol sulfate, alkylphenol ether sulfate, alkylethanolamide sulfate, alkylethanolamide ether sulfate, or alpha sulfo fatty acid or its ester, each having at least one alkyl or alkenyl group with 8 to 22, more usually 10 to 20, atoms of aliphatic carbon. The expression "ether" hereinafter refers to compounds containing one or more glyceryl groups and / or a polyoxyalkylene or oxyalkylene group especially a group containing f from 1 to 20 oxyethylene and / or oxypropylene groups. One or more oxybutylene groups may be additionally or alternatively. For example, the sulfonated or sulphonated surfactant may be sodium dodecyl benzene sulfonate, hexadecyl potassium benzene sulfonate, sodium dodecyl dimethyl benzene sulfonate, lauryl sodium sulfate, sodium tallow sulfate, potassium oleyl sulfate, monoethoxy lauryl ammonium sulfate, or sodium ethoxylate sulfate. 10 mol of cetyl monoethanolamine. 20 Other anionic surfactants useful according to The present invention includes alkyl sulfosuccinates, such as sodium di-2-ethylhexylsulfosuccinate and sodium dihexylsulfosuccinate, alkyl ether sulfosuccinates, alkyl sulfosuccinamates, alkyl ether sulfosuccinates, acyl sarcosinates, taurides Acyl, isethionates, soaps such as stearates, palmitates, resinates, oleates, linoleates, and alkyl ether carboxylates. Alkyl phosphonates and anionic phosphate esters, methylene imino and amino alkyl phosphonates can also be used. In each case, the anionic surfactant typically consists of at least one aliphatic hydrocarbon chain having from 8 to 22, preferably 10 to 20 carbon atoms, and, in the case of ethers, one or more glyceryl groups and / or 1 to 20 oxyethylene and / or oxypropylene and / or oxybutylene. The preferred anionic surfactants are the sodium salts. Other salts of commercial interest include those of potassium, lithium, calcium, magnesium, ammonium, monoethanolamine, diethanolamine, triethanolamine, alkyl amines containing up to seven aliphatic carbon atoms and hydroxyalkyl phosphonium and / or. I rent. The surfactant may optionally contain or consist of nonionic surfactants. The nonionic surfactant can be, for example, a C? 0-22 alkanolamide of a mono or di-lower alkanolamine, such a coconut monoethanolamide. Other nonionic surfactants which may optionally be present include tertiary acetylenic glycols, polyethoxylated alcohols, polyethoxylated mercaptans, polyethoxylated carboxylic acids, polyethoxylated amines, polyethoxylated alkylolamides, polyethoxylated alkylphenols, polyethoxylated glyceryl esters, polyethoxylated sorbitan esters, polyethoxylated phosphate esters, and the propoxylated and proproxylated or ethoxylated analogues of all the above-mentioned ethoxylated nonionics, all having an alkenyl or C 8-22 alkyl group and up to 20 ethyleneoxy and / or propyloxy groups. Also included are polyoxypropylene / polyethylene oxide copolymers, polyoxybutylene / polyoxyethylene copolymers and poly oxybutylene / polypropylene copolymers. The polyisobutylene, polyoxypropylene and polyethoxy compounds can be capped with, for example, benzyl groups to reduce the foaming tendency. The compositions of our invention may contain amphoteric surfactant. The amphoteric surfactant can be for example a betaine, for example, a betaine of the formula: -R 3 N + CH 2 COO, wherein each R is an alkyl, cycloalkyl, alkenyl or alkaryl group and preferably at least one, and more preferably no more of an R, it has an average of 8 to 20, for example, 10 to 18 aliphatic carbon atoms and each other R has an average of from 1 to 4 carbon atoms. Particularly preferred are the quaternary imidazoline betaines of the formula: - CH 2 CH 2 N + N CH2COO 'I R1 R wherein R and R1 are alkyl, alkenyl, cycloalkyl, alkaryl or alkanol groups having an average of 1 to 20 aliphatic carbon atoms and R preferably has an average of 8 to 20, for example, 10 to 18 aliphatic carbon atoms and R 1 preferably has 1 to 4 carbon atoms. Other amphoteric surfactants for use according to our invention include alkyl amine ether sulfates, sulfobetaines and other quaternized imidazoline sulphonic acids or quaternary amine and its salts, and amphoteric ion surfactants, for example N-alkyl taurines, amines of carboxylated amido such as RCONH (CH2) 2N * (CH2CH2CH3) 2CH2CO "2, and amino acids having, in each case, hydrocarbon groups capable of conferring properties of the surfactant (for example, alkyl, cycloalkyl, allyl or alkaryl groups having from 8 to 20 aliphatic carbon atoms.) Typical examples include 2-tallow alkyl, 1-selo-amido alkyl, 1-midazoline-1-carboxymethyl and 2-coco-imidazoline alkyl N-carboxymethyl-2 (hydroxyalkyl). Generally speaking any agent compound amphoteric or water-soluble amphoteric ion surfactant comprising a hydrophobic portion including alkenyl or C 8-2 alkyl group and a portion that contains a quaternary ammonium or amine group and a carboxylate, sulfate, or sulfonic acid group can be used in our invention. The compositions of our invention may also include cationic surfactants. The cationic surfactant can be for example an alkylammonium salt having a total of at least 8, usually 10 to 30, for example 12 to 14 aliphatic carbon atoms, especially a tri or tetraalkylammonium salt. Typically, the alkylammonium surfactants to be used according to our invention have one or at most two relatively long aliphatic chains per molecule (e.g., chains having an average of 8 to 12 carbon atoms each, usually 12 to 18 atoms) carbon) and two or three relatively short chain alkyl groups having 1 to 4 carbon atoms each, for example, methyl or ethyl groups, preferably methyl groups. Typical examples include ammonium salts of trimethyl dodecyl. Benzalkonium salts having an alkyl group of 8 to 20 C, two alkyl groups of 1 to 4 carbons and a benzyl group are also useful. Another class of cationic surfactant useful according to our invention comprises N-alkyl pyridinium salts wherein the alkyl group has an average of from 8 to 22, preferably 10 to 20, carbon atoms. Other similarly alkylated heterocyclic salts, such as N-alkyl isoquinolium salts, may also be used. Dialkylammonium alkylaryl salts, having an average of from 10 to 30 aliphatic carbon atoms are useful, for example, those in which the alkylaryl group is a benzene alkyl group having an average of from 8 to 22, preferably 10 up to 20 carbon atoms and the other two alkyl groups usually have from 1 to 4 carbon atoms, >; for example, methyl groups. Other classes of cationic surfactants which are of use in our invention include quaternized imidazoline or alkyl imidazoline salts having at least one alkyl group in the molecule with an average of 8 to 22 preferably 10 to 20 carbon atoms. Typical examples include imidazolinium salts of hydroxyethyl methyl alkyl, imidazolinium salts of hydroxyethyl benzyl alkyl, and salts of 2-alkyl-1-alkylamidoethyl imidazoline. Another class of cationic surfactant to be used according to our invention comprises amido amines such as those formed by reacting a fatty acid having 2 to 22 carbon atoms or a similar ester, glyceride or amide forming derivatives thereof, with a di or polyamine, such as, for example, ethylene diamine or diethylene triamine, in such a ratio to leave at least one free amine group. The quaternized amido amines can be used in a similar manner. The phosphonium hydroxyalkyl and phosphonium alkyl salts having a C 8-2 alkyl group and three hydroxyalkyl or C 1 alkyl groups can also be used as cationic surfactants in our invention. Typically, the cationic surfactant can be any water soluble compound which has a positively ionized group, usually comprising a nitrogen atom, and either one or two alkyl groups, each having an average of from 8 to 22 carbon atoms . The anionic portion of the cationic surfactant may be any anion conferring water solubility, such as formate, acetate, lactate, tartrate, citrate, chloride, nitrate, sulfate or an alkyl sulfate ion having up to 4 carbon atoms such as methosulfate. A surface active anion such as an organic sulfonate or higher alkyl sulfate is not preferable. The cationic or nonionic, polyfluorinated anionic surfactant may also be useful in the composition of our invention. Examples of such surfactants are polyfluorinated alkyl sulfates and polyfluorinated quaternary ammonium compounds. The compositions of our invention may contain a semi-polar surfactant such as an amine oxide, for example, an amine oxide containing one or two C8 alkyl groups. 22 (preferably one), the surfactants or remaining surface active agent being preferably lower alkyl groups, for example, benzyl groups or C 1 -4 alkyl groups. Particularly preferred to be used according to our invention are the surfactants which are effective as wetting agents, typically such surfactants are effective in lowering the surface tension between the water and a hydrophobic solid surface. We prefer surfactants that do not stabilize the foams to a substantial degree. Mixtures of two or more of the above surfactants can be used. In particular mixtures of nonionic surfactants with cationic and / or amphoteric and / or semi-polar surfactants or with anionic surfactants can be used. Typically, we avoid mixtures of anionic or cationic surfactants, which are often less mutually compatible. Preferably, the THP and the surfactant are present in a relative weight concentration of from 1: 1000 to 1000: 1, more usually 1: 50 to 200: 1, typically 1: 20 to 100: 1, more preferably 1: 10 to 50: 1. for example 1: 1 to 20: 1 especially 2: 1 to 15: 1. Effective doses of the mixture are typically from 0.5 ppm to 2,000 ppm, more usually 2 ppm to 1,000 ppm, for example 5 ppm to 500 ppm especially 10 to 250 ppm. The composition may additionally contain other insecticides, water dispersants, antifoams, solvents, anti-fouling inhibitors, corrosion inhibitors, oxygen scavengers and / or flocculants. Our invention includes aqueous solutions containing a biocidally active concentration of a composition of the invention. Such solutions can be water systems or water based products containing functional ingredients as described in GB 2 145 708. Our invention also includes formulations, anhydrous and concentrated aqueous, adapted to provide the above-mentioned products in dilution with water. Corrosion inhibitors or antifoulants that can be added to the water to be treated in conjunction with the present invention include phosphonates, polymaleates, polyacrylates, polymethacrylates, polyphosphates, phosphate esters, soluble zinc salts, nitrite, sulfite, benzoate, tannin, lignin sulfonates, benzotriazoles and mercaptobenzothiazoles all added in conventional amounts. The corrosion inhibitors and / or antifoulants can be added to the water separately or in association with the phosphonium compound and the surfactant. Oxygen scavengers, flocculants such as polyacrylamide dispersants, anospumes such as silicones or polyethyleneoxylated antifoams or other insecticides such as isothiazolones or tin compounds can be added to the water. The mixture according to our invention can be prepared in situ by adding the THP, the synergistic biopenetrant product and optionally the surfactant separately to the water system to be treated. Alternatively and preferably the components can be premixed, either alone, provided they are miscible in the desired proportions, or with water or other solvents including polyhydric and monohydric alcohols C? -4, acetones, or dispersants such as polyelectrolytes. Typically, THP is miscible with cationic surfactants of the phosphonium and quaternary ammonium type, but mixtures with nonionic surfactants may require dilution with water or solvents. The microorganisms to be treated usually are bacteria, fungi, yeasts, and algae that grow in aquatic environments. Included in this classification are the bacteria that reduce sulphate, for example, Desulphovibrio, which can originate in oil installations, iron bacteria, for example, Gallionella and bacteria that form silt, for example, Pseudomonas, which lastly are particularly annoying in aerated aqueous systems. The water to be treated can be industrial cooling water, for example, for powder or chemical plant stations or for steel or paper or fermentation and can be used in closed circuit or in open circuit including its evaporation in cooling towers. Alternatively, the water may be processing water, especially processing water containing significant sources of nutrients for microorganisms such as brewing water for paper making plants and breweries. Injection water or drilling fluids for oil fields or water produced from oil fields or water used in reverse osmosis plants, for example, to provide industrial processes or boiler feed water, can be treated Other aquatic environments that can to be treated with the biocidal synergistic mixtures according to the method for the invention are the water for processing or cooling in on-board machines, manufacture of fertilizers, petroleum refineries, manufacture of primary metals, for example, steel or copper, petrochemicals, manufacture of rubber , textile and fabric industries, industrial gas manufacturing, mineral recovery, glass and ceramics manufacturing, food industry, leather manufacturing, heavy and light engineering, including metal fabrication and automotive engineering, furniture manufacturing, electronics industry and coating of surfaces and manufacturing of adhesives or other manufacturing industries. The process is also applicable to the treatment of geothermal water, water for domestic services, air conditioning systems and institutional and industrial heating and water used for hydrostatic testing of ducts and vessels, swimming pools and as cooling water for ships and marine engines. The invention is also applicable to the control of microbial contamination in a wide variety of water-based products. For example, the compositions of the invention can be added to a variety of solutions and emulsion compositions such as paints, knife lubricants, asphalt and tar emulsions, adhesives, herbicides and insecticides, as well as to concentrated or solid compositions for addition to water in the preparation of such products. Therefore, the invention further provides aqueous based products that are subjected to microbial damage to which a bactericidal or bacteriostatic amount of a THP salt, a biopenetrating synergistic product as mentioned above, and optionally, a surfactant agent has been added. Typically such compositions consist of aqueous solutions, suspensions or emulsions of at least one functional ingredient, together with a minor proportion of a composition of the invention, sufficient to inhibit the growth of microorganisms therein. The systems to which the invention is particularly applicable are those which include the circulation or storage of substantial amounts of water, under conditions which favor the multiplication of bacteria, especially resistant bacteria such as P Aeruginosa, for example, conditions which include keeping or collecting Periodically, water at super-environment temperatures that favor bacterial proliferation, or maintain nutrients for bacteria in water systems. The invention will be illustrated by the following examples.

Example 1 The THPS / WSCP mixture was compared with the THP / anionic surfactant products to control legionella pneumophila.

METHODOLOGY \ 0 15 twenty -25 Notes: i) ND - NOT DETECTED ii) The control was 1 x 103 iii) The following conclusions apply I > A - Good activity within 4 hours at 50 ppm or more N3 > B - Good activity within 3 hours in 100 ppm, or 6 hours in 50 ppm > Example - Good activity within 3 hours at 50 ppm or more.

The example of the invention also showed superior performance for formulations of conventional THP surfactants, for WSCP alone and for THP only to reduce planktonic bacteria. The example gave less than half the foaming observed using formulations containing surfactant.

Example 2 An aqueous solution comprising 50% THPS and WSCP at 2% was added to infected beads of alginate with bacteria that reduce the sulfate. When dosed at 250 ppm, the solution gave a 100-fold reduction in bacterial counts, compared to a control, after two weeks of incubation. At 500 ppm the solution gave a total death.

Example 3 The alginate bead test of examples 2 and 3 are repeated using sodium naphthalene sulfonate / formaldehyde condensate as the synergistic product. At 250 ppm the solution gave a 100-fold reduction in bacterial count after two weeks of incubation. At 500 ppm the solution gave a total death. The volume of foam generated when air was bubbled through the system containing 750 ppm of the active biocidal mixture was half that using THP alone.

Example 4 The alginate bead test of Example 1 was repeated using generally heterotrophytic bacteria and a residence time of two hours. For comparison we use the commonly used commercial THP insecticide product which is an aqueous solution comprising 50% THPS and 2% anionic surfactant commercially available under the Trade Mark "DOWFAX" 2A. Various mixtures each comprising 50% THPS and 2% biopenetrant were compared in doses of 250 ppm and 125 ppm. The logarithmic reduction in bacterial counts is given in the table. TABLE In each case the biopenetrant of the invention showed improved biocidal activity compared to the surfactant in the comparative example, and gave substantially less foaming.

Claims (12)

1. CLAIMS 1. A biocidally synergistic mixture comprising THP, at least one biopenetrant non-surfactant compatible with THP and, optionally, a surfactant, characterized in that said biopenetrant is a polymer or copolymer, having a plurality of quaternary ammonium groups, and / or a naphthalene alkyl or benzene alkyl sulfonate having less than 5 aliphatic carbon atoms, and / or a phosphono polycarboxylic acid.
2. 2. A composition according to claim 1, characterized in that it comprises as a biopenetrant a compound having a polymeric cation with the formula R is a divalent organic group, constituting with the ammonium group a monomeric residue or separately selected from two or more comonomer residues; each R is a hydroxyalkyl or alkyl group, X is hydrogen or a monovalent organic or inorganic final cover unit; and n is from 3 to 3000.
3. 3. A composition according to claim 1, characterized in that the biopenetrant non-surfactant is a polyethylene of methylated polyethylene comprising a polymeric cation of the formula: CH3 [N? (CH3) 2CH2CH2] nNf (CH3 ) 3 wherein n is from 2 to 10.
4. A composition according to any of the preceding claims, characterized in that the biopenetrant non-surfactant comprises poly [oxyethylene dihydrochloride) dimethyliminio) ethylene (dimethyliminio) ethylene].
5. A composition according to any of the preceding claims, characterized in that it consists of an aqueous solution in which the concentration of THP is from 10 to 75% by weight of the solution and the concentration of synergistic biopenetrant product not surfactant is from 0.1 to 10. % by weight of the solution.
6. 6. A composition according to any of the preceding claims, characterized in that it also comprises a surfactant.
7. 7. A composition according to claim 14, characterized in that the surfactant is present in a weight ratio of from 50: 1 to 1: 200 based on the weight of the THP.
8. 8. A method for treating aqueous systems for preventing, inhibiting or removing microbial contamination, comprising adding thereto, together or separately, the components of a biocidally synergistic mixture comprising THP, at least one biopenetrant non-surfactant agent compatible with THP and, optionally, a surfactant, characterized in that said biopenetrant comprises a polymer or copolymer, having a plurality of quaternary ammonium groups, a naphthalene alkyl or benzene alkyl sulfonate having less than 5 aliphatic carbon atoms and / or a system.
9. 9. A method according to claim 8, characterized in that the biopenetrant non-surfactant comprises a condensate of formaldehyde, acetone and / or THP with a phenol, aryl sulfonate, sulfone, sulfonamide, urea, melamine, dicyandiamide or alkyl amine Ci a ? 10.
10. A method according to claim 8 or 9, characterized in that said biopenetrant comprises urea and / or a THP condensate of urea. eleven .
11. A method for treating aqueous systems for preventing, inhibiting or removing microbial contamination, characterized in that it comprises adding thereto, together or separately, the components of a composition according to any of claims 1 to 7.
12. 12. A method according to any of claims 8 to 11, characterized in that the proportion of total weight of THP and biopenetrants dosed to the system is from 2 to 1000 ppm.