MXPA00000818A - Methods and compositions for controlling biofouling using amino methyl phosphonic acids - Google Patents

Abstract

The invention relates to a method to inhibit bacteria from adhering to a submergible surface.The method contacts the submergible surface with an effective amount of at least one amino methyl phosphonic acid or salt thereof to inhibit bacterial adhesion to the submergible surface. The invention also relates to a method for controlling biofouling of an aqueous system. This method adds an effective amount of at least one amino methyl phosphonic acid or salt thereof to inhibit bacteria from adhering to a submerged surface within the aqueous system. This method effectively controls biofouling without substantially killing the fouling organisms. The amino methyl phosphonic acid used in the methods of the invention has the formula R1R2NCH2P(O)(OH)2. In this formula, R1 and R2 are independently a C6-C20 alkyl group or a CH2P(O)(OH)2 group. However, R1 and R2 are not both a CH2 P(O)(OH)2 group. Alternatively, R1 and R2, together with the N, may also form a 5-8 membered heterocyclic ring having formula (a). In the heterocyclic ring, X is O, NH, or CH2. The salt of an amino methyl phosphonic acid can be an acid salt or a quaternized amino methyl phosphonic acid salt. The invention also relates to a composition containing amino methyl phosphonic acids or salts thereof and useable in the above methods. The compositions comprise at least one amino methyl phosphonic acid or salt thereof in an amount effective to inhibit bacteria from adhering to submergible or submerged surfaces.

Description

METHODS AND COMPOSITIONS FOR CONTROLLING BIOINCRUSTATION USING AMINOMETHYMPHOSPHONIC ACIDS DESCRIPTION OF THE INVENTION The invention uses an aminomethylphosphonic acid or a salt thereof to inhibit bacterial adhesion to submergible or submerged surfaces, particularly those surfaces within an aqueous system. The invention also relates to methods and compositions for controlling biofouling. Microorganisms adhere to a wide variety of surfaces, in particular surfaces in contact with aqueous fluids that provide a suitable medium for microbial growth. For example, it is known that microorganisms adhere to the hulls of ships, marine structures, teeth, medical implants, cooling towers and heat exchangers. By adhering to such submerged or submerged surfaces, microorganisms can soil the surface or deteriorate it. In mammals, (for example, humans, livestock, pets), microorganisms attached to a surface can lead to health problems. Bacterial plaque, for example, results from the adhesion of microorganisms to the surfaces of the teeth. Medical implants with undesirable microorganisms adhering to their surface often become excessively incrusted and must be replaced. Scientific studies have shown that the first stage of biofouling in aqueous systems is generally the formation of a very thin biofilm on submerged or submerged surfaces, that is, on surfaces exposed to an aqueous system. It is known that microorganisms such as bacteria, when fixing and colonizing a submerged surface, form a biofilm in it and modify the surface to favor the development of a more complex community of organisms that make up the advanced biofouling of an aqueous system and its submerged surfaces. A general review of the mechanisms of the importance of biofilm as well as the initial stage of biofouling is given in CA Kent in "Biological Fouling: Basic Science and Models" (in Meló, LF, Bott, TR, Bernardo, CA (eds. .), Fouling Science and Technology, NATO ASI Series, E Series, Applied Science: No. 145, Kluwer Acad. Publishers, Dordrecht, The Netherlands, 1988). Certain literary references include M. Fletcher and G. I. Loeb, Appl. Environ. Microbiol. 37 (1979) 67-72; M. Humphries et. al., FEMS Microbiology Ecology 38 (198β) 299-308; and M. Humphries et. al., FEMS Microbiology Letters 42 (1987) 91-101. Biofouling, or biological fouling, is a persistent nuisance or problem in a wide variety of aqueous systems. Biofouling, both microbiological Like the macrobiological, it is caused by the constructions of microorganisms, macroorganisms, extracellular substances and dirt and debris that are trapped in the biomass. Microorganisms involved include microorganisms such as bacteria, fungi, yeasts, algae, diatoms, protozoa and macroorganisms such as macroalgae, barnacles and small molluscs such as Asian clams or zebra mussels. Another phenomenon of objectionable biofouling occurs in aqueous systems, particularly in aqueous fluids of industrial processes, and is the formation of silt. Slime formation can occur in systems of clean, nauseating or salty water. The silt consists of entangled deposits of microorganisms, fibers and debris. It can be fibrous, doughy, elastic, like the consistency of the tapioca, or hard and has an undesirable characteristic, an odor that is different from the aqueous system in which it was formed. The microorganisms involved in the slime are basically different species of bacteria that are formed by spores or that are formed without spores, in particular forms of encapsulated bacteria that secrete gelatinous substances that envelop or encasillan the cells. Silt microorganisms include filamentous bacteria, mold-like filamentous fungi, yeasts, and organisms similar to yeasts.

Biofouling, which often degrades an aqueous system, can manifest itself as a variety of problems, such as loss of viscosity, formation of gases, undesirable odors, decreased pH, color change, and solidification. Additionally, the degradation of an aqueous system can cause fouling of the water treatment system, which may include, for example, cooling towers, pumps, heat exchangers, pipes, heating systems, washing systems and the like. Biofouling can have an adverse economic impact when it occurs in industrial water processes, for example, in cooling waters, by working with fluid metals or other recirculating water systems, such as those used in papermaking or textiles. If left unchecked, biological fouling of industrial process water can interfere with operations processes, decrease efficiency, waste energy, clog the water treatment system and even degrade the quality of the product. For example, water cooling systems used in power plants, refineries, chemical plants, air conditioning systems and other industrial operations often have biofouling problems. The organisms born in the air dragged by cooling towers as much as organisms born in water from water supply systems commonly contaminate these water systems. Water in such systems generally provides an excellent medium for the growth of the same organisms. Aerobic and heliotropic organisms flourish in the towers. Other organisms grow and colonize areas such as sinks, pipes, heat exchangers, etc. if left unchecked, the resulting biofouling can clog the towers, block the pipes and cover the surfaces of the heat transformers with silt lids and other biological doughs. This prevents proper operation, reduces cooling efficiency, and perhaps even more importantly, increases the costs of the entire process. Industrial processes subject to biofouling also include making paper, manufacturing pulp, paper, cardboard, etc., and textile manufacturing, particularly non-woven textiles left in the water. This industrial process generally recirculates large quantities of water under conditions that favor the growth of organisms that bio-crust. Papermaking machines, for example, handle very large volumes of water in recirculating systems called "whitewater systems". The supply to a paper machine typically contains only approximately 0.5% solids to make fibrous and non-fibrous papers, which means that for each ton of paper approximately 200 tons of water pass through the penstocks. Most of this water recirculates in whitewater systems. White water systems provide an excellent means for the growth of microorganisms that bio-crust. That growth may result in the formation of silt and other deposits in the floodgates, water distribution networks and paper making equipment. Such biofouling can not only interfere with water and the circulation of the diluted pulp, but when there is an escape, it can cause stains, holes and odors in the paper as well as costly ruptures due to the rupture of the paper web in the operations of the paper making machine. Biofouling in recreational waters such as swimming pools or spas or decorative waters such as ponds or fountains can severely reduce people's enjoyment of them. The biological incrustation often results in undesirable odors. More important, particularly for recreational waters, biofouling can degrade water quality to such an extent that it becomes inconvenient for use and may even pose a health risk.

Treated water, such as industrial process water and recreational water, is also vulnerable to biofouling and its associated problems. The treated water includes water for personal grooming, cistern water, septic water and sewage treatment water. Due to the nature of the waste contained in the treated water, these water systems are particularly susceptible to biofouling. To control biofouling, the technique has traditionally treated a water system affected with chemicals (biocides) in concentrations sufficient to kill or inhibit most of the growth of bio-fouling organisms. See, for example, US Patent Nos. 4,293,559 and 4,295,932. For example, chlorine gas and hypochlorite solutions made with gas have long been added to water systems to kill or inhibit the growth of bacteria, fungi, algae and other pesky organisms. However, chlorine compounds can not only damage the materials used for the construction of aqueous systems, they can also react with organic substances to form undesirable substances in effluent streams, such as chloromethanes and chlorinated dioxins that are carcinogenic Certain organic compounds such as methylene bisthiocyanate, dithiocarbamates, haloorganics, and Quaternary ammonium surfactants have also been used. Although many of them are quite efficient at killing microorganisms or inhibiting their growth, they can also be toxic or harmful to humans, animals or other non-target organisms. One possible way to control the biofouling of the aqueous systems, which includes the associated submerged surfaces, would be to prevent or inhibit the adhesion of the bacteria to the submerged surfaces within the aqueous system. This can be done, of course, using microbicides which, however, generally suffer from some of the disadvantages mentioned in the foregoing. As an alternative, the present invention provides method and compositions useful for substantially inhibiting the adhesion of bacteria to submerged or submerged surfaces and for controlling the biofouling of aqueous systems. The invention obviates the disadvantages of the above methods. Other advantages of this invention will become apparent upon reading the specifications and appended claims. The invention relates to a method that inhibits the adhesion of bacteria to a submergible surface. The method contacts a submergible surface with an effective amount of at least one aminomethylphosphonic acid or an isomer salt to inhibit adhesion of the bacteria to a submergible surface. Aminomethylphosphonic acid used in this method has the following formula RxR2NCH2P (0) (OH) 2. In this formula, R1 and R2 are, independently, a C6-C20 alkyl group or a CH2P (0) (OH) 2- group, however, R1 and R2 not both a CH2P (0) (OH) 2- group Alternatively, R1 and R2 together with N can also form a 5-8 membered heterocyclic ring having the formula: In the heterocyclic ring, X is O, NH or CH2. The dotted line indicates that the group X can occupy different positions in a particular heterocyclic ring. The invention also relates to a method for controlling biofouling in an aqueous system. This method adds to an aqueous system an effective amount of at least one aminomethylphosphonic acid described above, or a salt thereof to inhibit the adhesion of the bacteria to a submerged surface within the aqueous system. This method effectively controls biofouling without substantially killing the bacteria. The invention also relates to a composition for controlling the biofouling of an aqueous system. Biofouling comprises at least one acid aminomethylphosphonic or a salt thereof in. an amount effective to inhibit the adhesion of bacteria to a submergible surface or a submerged surface within the aqueous system. In a modality, this invention relates to a method for inhibiting the adhesion of bacteria to a submerged surface. A submersible surface is one that may be at least partially covered, flooded, or wetted with a liquid such as water or other aqueous or liquid fluid. The surface may be in contact with the liquid intermittently or continuously. As discussed above, examples of submersible surfaces include, but are not limited to, boat hulls or boats, marine structures, teeth, medical implants, surfaces within an aqueous system such as the inside of a pump, pipe, cooling tower or heat exchanger. A submersible surface can be composed of hydrophobic, hydrophilic or metallic materials. Advantageously, using an aminomethylphosphonic acid or a salt thereof according to the invention can effectively inhibit the adhesion of bacteria to hydrophobic, hydrophilic or metallic submergible or submerged surfaces. In order to inhibit the adhesion of bacteria to a submergible surface, the method contacts the submergible surface with an aminomethylphosphonic acid or a come out of it The surface is contacted with an effective amount of aminomethylphosphonic acid or a salt thereof, or with a mixture of aminomethylphosphonic acids or salts thereof, to inhibit the adhesion of the microorganisms on the surface. Preferably, an aminomethylphosphonic acid or its salt is applied as a pretreatment to the submergible surface before being submerged in an aqueous system. The aminomethylphosphonic acid or salts thereof may be applied to a submergible surface using means known in the art. For example, as discussed above, the aminomethylphosphonic acid or a salt thereof can be applied by spraying, coating or dipping the surface in a liquid formulation containing the aminomethylphosphonic acid or a salt thereof. Alternatively, the aminomethylphosphonic acid or a salt thereof as a paste which is then spread or smeared with a brush on the submergible surface. Advantageously, the aminomethylphosphonic acid or a salt thereof may be the component of a composition or formulation commonly used in a particular submergible surface. "Inhibiting the adhesion of bacteria" to a submersible surface means allowing a limited or significant amount of bacterial adhesion for a desired period of time. Preferably, that there is essentially no bacterial adhesion and more preferably that it is prevented. The The amount of aminomethylphosphonic acid or a salt thereof used should allow only a small or insignificant adhesion of the bacteria and can be determined by a routine test. Preferably, the amount of aminomethylphosphonic acid or a salt thereof used is sufficient to apply at least one monoclinic film of aminomethylphosphonic acid or a salt thereof to the submergible surface. Such a film preferably covers the submersible surface entirely. By contacting the submersible surface with an aminomethylphosphonic acid or a salt thereof according to this method allows the surface to be treated against bacterial adhesion. Accordingly, the surface can be contacted with an aminomethylphosphonic acid or a salt thereof and then immersed in the aqueous system. The present invention also relates to a method for controlling biofouling in an aqueous system. An aqueous system comprising not only an aqueous fluid or liquid flowing through the system but also the submerged surfaces associated with this system, the submerged surfaces being those surfaces in contact with the fluid or aqueous liquid. Like the submergible surfaces discussed above, submerged surfaces include, but are not limited to, the inside surfaces of pipes or pumps, the walls of a cooling tower or gates, heat exchangers, wire cloth, etc. In brief, the surfaces in contact with the aqueous fluid or liquid are submerged surfaces and are considered part of the aqueous system. The method of the invention adds at least one aminomethylphosphonic acid or a salt thereof to an aqueous system in an amount that effectively inhibits the adhesion of the bacteria to the submerged surface within the aqueous system. At the concentration used, this method effectively controls the biofouling of the aqueous system without substantially killing the bacteria. "Control of biofouling" of the aqueous system means controlling the amount or extent of biofouling at and above the desired level and for a desired period of time for the particular system. This can eliminate biofouling of the aqueous system, reduce scaling to a desired level or prevent biofouling altogether or about a desired level. According to the present invention, "inhibiting the adhesion of bacteria" to a submerged surface within the aqueous system means allowing a small or insignificant amount of bacterial adhesion for a desired period of time for a particular system.

Preferably, essentially that there is no bacterial adhesion and more preferably, bacterial adhesion is prevented. Using aminomethylphosphonic acid or a salt thereof according to the invention can, in many cases, break or reduce other adhesions of microorganisms to undetectable levels and maintain that level for a significant period of time. While some aminomethylphosphonic acids or salts thereof may exhibit biocidal activity at concentrations of approximately certain limit levels, the aminomethylphosphonic acids or salts thereof effectively inhibit bacterial adhesion generally well below such limit levels. According to the invention the aminomethylphosphonic acid or salt thereof inhibits bacterial adhesion without substantially killing the bacteria. Therefore, the effective amount of the aminomethylphosphonic acid or a salt thereof used according to the invention is below its toxic limit, and the aminomethylphosphonic acid or salt thereof also has biocidal properties. For example, the concentration of aminomethylphosphonic acid may be ten or more times below the toxic limit level. Preferably, the aminomethylphosphonic acid or salt thereof should also not harm non-target organisms that may occur in the aqueous system.

An aminomethylphosphonic acid or salt thereof or a mixture of aminomethylphosphonic acids or salts thereof, can be used to control biofouling in a wide variety of aqueous systems such as those discussed above. These aqueous systems include, but are not limited to, industrial aqueous systems, aqueous treated water systems, and recreational water systems. As discussed above, examples of industrial aqueous systems are those of metal work, fluids, cooling water (eg, intake of cooling water, effluent cooling water, and recirculating cooling water), and other water systems recirculating materials such as those used in papermaking or in the manufacture of textiles. Aqueous treated water systems include waste water systems (eg industrial, private and municipal waste water systems), water for bathrooms and water treatment systems, (eg, sewage treatment systems). Swimming pools, fountains, decorative or ornamental ponds, ponds or streams, etc., give examples of water systems for recreation. The effective amount of aminomethylphosphonic acid or salt thereof to inhibit the adhesion of bacteria to a submerged surface and in a particular system will vary a bit depending on whether the system aqueous is protected, from the conditions of microbial growth, the extent of any biofouling that exists and the degree of biofouling control that is desired. For a particular application, the quantity to be chosen can be determined with a routine test with several quantities, before the treatment of the affected system in its entirety. In general, an effective amount used in an aqueous system can vary from about 1 to 500 parts per million and more preferably from 20 to 100 parts per million of the aqueous system. The aminomethylphosphonic acid used in the present invention has the following general formula R1R2NCH2P (0) (OH) 2- In this formula, R1 and R2 are independently a Cg-C2o alkyl group or a CH2P (0) (OH) 2 group. But, R1 and R2 are not both a CH2P (0) (OH) 2 group. Preferably, R1 is a C6-C20 alkyl group and R2 is a CH2P (0) (OH) 2 group. When R 1 or R 2 is an alkyl group, it is preferably a C 1 -C 7 alkyl group, more preferably a C 10 -C 14 alkyl group, and most preferably a C 2 alkyl group. The alkyl group may be linked through a terminal carbon or a carbon in the alkyl chain. An alkyl group can contain carbon-carbon double and triple bonds and can also be branched or unbranched.

Alternatively, R1 and R2 together with N can also form a 5-8 membered heterocyclic ring having the formula: In the heterocyclic ring, X is 0, NH, or CH2. The dotted line indicates that the group X can occupy different positions in a particular heterocyclic ring. Preferably, the heterocyclic ring is a 5- or 6-membered ring. Preferred specific rings include morpholinyl and piperidinyl. The specifically preferred aminomethylphosphonic acids of the above formula include the aminomethylphosphonic acid compound (a); the octyl aminomethylphosphonic acid compound (b); decyl aminomethylphosphonic acid compound, (c); the compound dodecyl aminomethylphosphonic acid (d); the octadecyl aminomethylphosphonic acid compound (e); the compound dioctyl aminomethylphosphonic acid (f); and the morpholino aminomethylphosphonic acid compound (g). The aminomethylphosphonic acids useful in the invention are available either commercially in houses supplying chemicals or can be prepared with raw material using the methods of literature already known. For example, an aminomethylphosphonic acid can be prepared by the following method. An acid, such as HCl, is added dropwise to a desired amine in water. Generally an excess of acid is used, about 2.4 moles of acid per mole of amine. The mixture is then heated to about 70 ° C, before adding the phosphoric acid. Phosphoric acid can be added slowly for approximately 30 minutes. The molar ratio of phosphoric acid to amine depends on whether a primary or a secondary amine is used and the desired aminomethylphosphonic acid is prepared. After adding the phosphoric acid, the reaction mixture is cooled to about 40 ° C, before a formaldehyde is added dropwise. It is preferred to add the formaldehyde in an aqueous solution, for example a solution of 37% formaldehyde in water. After adding the formaldehyde, the reaction is refluxed to ensure a complete reaction. Having it reflowed for approximately five hours is usually sufficient. The reaction can then be cooled to room temperature and the product which is aminomethylphosphonic acid can be collected by concentration and dried. Methods for the preparation of various aminomethylphosphonic acids are described in U.S. Patent Nos. 4,615,840, 3,234,124 and 3,288,846.

The salts of an aminomethylphosphonic acid can also be used in the present invention. Aminomethylphosphonic acids are amphoteric, that is, they exhibit both acid and base properties. Accordingly, two types of aminomethylphosphonic acid salts can be formed: a salt of the acid moiety and a salt of the base or nitrogen moiety. The salts of the acid moiety (referred to as "acid salts") include, but are not limited to, metal alkali and quaternary ammonium salts. The salts of the base or nitrogen moiety (referred to as "quaternized amino methyl phosphonic acid salts") has the following general formula: R 1 R 2 R 3 N + P (O) 2 (OH) wherein R 1 and R 2 are as defined above and R 3 is , for example, a hydrogen or a C? -C2o alkyl group, such as those discussed above. The methods according to the invention for water treatment can be partial or total. Aminomethylphosphonic acid or a salt thereof can be used with other chemical treatments, particularly with biocides (eg, algicides, fungicides, bactericides, molluscicides, oxidants, etc.), stain removers, clarifiers, flocculants, coagulants, or other chemicals commonly used in the water treatment. For example, submergible surfaces can be contacted with an aminomethylphosphonic acid or a salt thereof as a precursor. treatment to inhibit bacterial adhesion and placed in an aqueous system using a microbicide to control the growth of microorganisms. 0 good, an aqueous system that is suffering from a dense biological encrustation can be treated first with a suitable biocide to overcome the existing encrustation. An aminomethylphosphonic acid or a salt thereof can then be used to maintain the aqueous system. Alternatively, aminomethylphosphonic acid or a salt thereof can be used in combination with a biocide to inhibit bacterial adhesion to submerged surfaces within the aqueous system while the biocide acts to control the growth of microorganisms in the aqueous system. Such • combination generally allows less use of microbicides. "Controlling the growth of microorganisms" in an aqueous system means controlling towards, at, or below a desired level and for a desired period of time for a particular system. This can be by eliminating the microorganisms or preventing their growth in an aqueous system. The aminomethylphosphonic acid or a salt thereof can be used in the methods of the invention as a liquid or solid formulation. Accordingly, the present invention also relates to a composition containing an aminomethylphosphonic acid or a salt thereof. same. The composition comprises at least one aminomethylphosphonic acid or a salt thereof in an amount effective to inhibit bacterial adhesion on a submergible or submerged surface within an aqueous system. When used in combination with another chemical treatment such as a biocide, the composition may also contain a chemical. If formulated together, aminomethylphosphonic acid or a salt thereof and a chemical for water treatment should not be subjected to adverse interactions that would reduce or eliminate its effectiveness in the aqueous system. Separate formulations are preferred when adverse interactions may occur. Depending on its use, a composition according to the present invention can be prepared in various ways known in the art. For example, the composition can be prepared in liquid form as a solution, dispersion, emulsion, suspension or paste; as a dispersion, suspension, or paste in a non-solvent; or as a solution by dissolving the aminomethylphosphonic acid or a salt thereof in a solvent or solvent combinations. Suitable solvents include, but are not limited to acetone, glycol, alcohols, ethers or other water dispersible solvents. Aqueous formulations are preferred. The composition can be prepared as a liquid concentrate to be diluted before use. pretend to give it. Common additives such as surfactants, emulsifiers, dispersants and the like can be used as is known in the art to increase the solubility of aminomethylphosphonic acid or its salts as well as other components in a liquid composition or liquid system, such as those given in a composition aqueous or an aqueous system. In many cases, the composition of the invention can be solubilized by simple agitation. The dyes or fragrances can be added for the corresponding applications such as water for bathrooms or personal hygiene. A composition of the present invention can also be prepared in solid form. For example, the aminomethylphosphonic acid or salt thereof can be formulated as a powder or tablet using means known in the art. The tablets may contain a variety of excipients known in the art of making tablets such as dyes or other coloring agents and fragrances or perfumes. Other components known in the art such as fillers, adhesives, glidants, lubricants or anti-adhesives can be included. These latter components may be included to improve the properties of the tablets and / or the process of making the tablets. The following illustrative examples are given to make the nature of the invention clearer. Should It should be understood, however, that the invention is not limited to the specific conditions or details of the same examples. EXAMPLE 1: General Synthesis of an Aminomethylphosphonic Acid: 35% HCl is added dropwise to an amine in water in such a way that the molar ratio of the acid: amine is 2.4: 1. The resulting mixture is heated to 70 ° C before the phosphorus acid is added by dripping or for thirty minutes. After the addition is complete, the temperature is reduced to 40 ° C. Then 37% aqueous formaldehyde is added. The mixture is refluxed for five hours. The resulting aminomethylphosphonic acid is collected by filtration and dried. EXAMPLE 2: Synthesis of Octyl Aminomethylphosphonic Acid: Octyl amine (0.1 mol) is added to 40 grams of water in a three-neck laboratory beaker equipped with a stirrer and a thermometer. 35% HCl (0.24 mol) are added dropwise to the octyl amine mixture by means of an additional funnel, with agitator. Then the reaction mixture is heated until it refluxes for 30 minutes. The phosphoric acid (0.2 mole H3P03) is then added dropwise. The mixture is cooled to 30-40 ° C before formaldehyde (37%) (0.26 mol) is added dropwise. The reaction mixture is then heated to about 100 ° C and stirred for several hours, the resulting octyl aminomethylphosphonic acid is collected by filtration and dried. EXAMPLE 3: Test Method: The following method effectively defines the ability of a chemical compound to inhibit the adhesion of bacteria or to attack the already existing formation of adhering microorganisms, on various types of surfaces. Broadly speaking, reactors were constructed in which slides of approximately 2.54 cm (1 inch) by 7.62 cm (3 inches) (stainless steel or glass) were fixed on the edge of the bioreactor. The lower ends of the slides (approximately 5.08 cm (2 inches)) were immersed in a bacterial growth medium (pH 7) within the bioreactor that contained a known concentration of the test chemical. The inoculation with known bacterial species followed, the test solutions were stirred continuously for 3 days. Unless indicated otherwise in the following results, the medium within the reactor was cloudy at the end of the three days. This turbidity indicated that the bacteria proliferated in the medium despite the presence of the test chemical. This also shows that the chemical, in the concentrations tested, showed substantially a non-biocidal (bactericidal) activity. A dyeing procedure was then used on the slides to determine the amount of bacteria adhered to the surfaces of the slides. Construction of Bioreactors: The bioreactors comprise a 400 ml laboratory beaker. on which a lid was placed (the cover was a normal glass petri dish of 9 cm in diameter). With the lid removed, the slides of the chosen material were held by masking tape ends and were suspended inside the bioreactor at the upper end of the laboratory beaker. This allows the slides to be submerged within the test medium. Typically, four (replicated) slides were uniformly spaced around the bioreactor. The scores presented below are the average of the four replicates. A magnetic stirring bar was placed in the bottom of the unit, the lid was placed in its place and the bioreactor was boiled in autoclave. Two different types of material were used in the slides, for metal it was stainless steel and for hydrolic surface it was glass. Bacterial Growth Medium: The liquid medium used in the bioreactors was previously described by Delaquis, et al., "Detachment of Pseudomonas fluorescens from Biofilms on Glass Surfaces in Response to Nutrient Stress," Microbial Ecology 18: 199-210, 1989. The composition of the medium was: Glucose 1.0 g K2HP04 5.2 g KH2P04 2.7 g NaCl 2.0 g NH4C1 1.0 g MgSO4. 7H20 0.12 g Tracer Element 1.0 mL deionized H20 1.0 L Tracer Element Solution: CaCl2 1.5 g FeS04. 7H20 1.0 g MnS04. 2H20 0.35 g NaMo04 0.5 g Deionized H20 1.0 L The medium was boiled in an autoclave and then cooled. If a sediment will form in the middle of the autoclave, the medium was resuspended by shaking it before use. Bacterial Preparation Inoculations: bacteria of the genus Bacillus, Flavobacterium and Pseudomonas were isolated from a slime deposit in a litter bin and kept in continuous culture. The test microorganisms were separately precipitated in an agar culture dish and incubated at 30 ° C for 24 hours. With a sterile absorbent cotton, portions of the colonies were removed and suspended in sterile water. The suspensions were mixed very well and adjusted to an optical density of 0.858 (Bacillus), 0.625 (Flavobacterium), and 0.775 (Pseudomonas) at 686 nm. Production of Biofilm / Chemical Tests: To the four separated bioreactors, 200 ml of the sterile medium prepared above was added. The chemicals to be evaluated as biodispersants were first prepared as a common solution (40mg / 2ml) using either water or a mixture of acetone-methanol of 9: 1 (ac / MeOH) as solvent. A common solution of 1.0 ml of aliquot was added to the bioreactor using the magnetic stirrer moderately and continuously. This provided an initial concentration of 100 ppm for the test compound. A bioreactor (Control) does not contain any test compound. The aliquots (0.5 ml) of each of the three bacterial suspensions were introduced into each bioreactor. The bioreactors were shaken for three days to allow an increase in the colony of bacteria and deposition of cells on the surfaces of the slides. Evaluation of the Results: the following compounds were evaluated using the procedure described above: aminomethylphosphonic acid compound (a); octyl aminomethylphosphonic acid compound (b); decyl aminomethylphosphonic acid compound, (c); dodecyl aminomethylphosphonic acid compound (d); morpholin-aminomethyl-phosphonic acid compound (e); octadecyl acid compound aminomethylphosphonic (f); dioctyl aminomethylphosphonic acid compound (g). After the test was completed, the slides were removed from the bioreactors and placed vertically to allow the air to dry. The degree of adhesion of bacteria to the test surfaces was then estimated using dyeing procedures. The slides were briefly flamed to fix the cells to the surface and transferred two minutes to a container of Violet Gram Crystal (DIFCO Laboratories, Detroit, MI). The slides were gently rinsed under a running tap and dried very carefully. The degree of bacterial adhesion was determined by visual examination and subjective evaluation of each slide. The intensity of the dyeing is directly proportional to the amount of adhesion of bacteria. The following biofilm scores were obtained: 0 = essentially none 3 = moderate 1 = scarce 4 = dense 2 = mild Chemical treatments were evaluated with the Control that typically receives an average score for the four slides of the bioreactors in 3-4 ranges. Compounds that receive an average score of in the 0-2 range are considered effective to achieve adherence to bacteria to submerged slides. The results are shown in the following Table I. Table I: 1 Minimum inhibitory concentration (MIC) for each compound against the E. Aerogene bacteria using an 18 hour test of Basic Salts with a pH of 6 and a pH of 8. * SS = stainless steel EXAMPLE 4: The test method, the construction of the bioreactors, the bacterial growth medium, the preparation of the bacterial inoculation and the biofilm / chemical tests are the same as those used in EXAMPLE 3. Evaluation of the Results: The following compounds were evaluated using the procedure described above: hexyl aminomethylphosphonic acid compound (a); octyl aminomethylphosphonic acid compound (b); decyl aminomethylphosphonic acid compound (c); acid dodecyl aammiinnoommeettiillffoossffóónniiccoo (d); morpholino aminomethylphosphonic acid compound (e); octadecyl aminomethylphosphonic acid compound (f); dioctyl aminomethylphosphonic acid compound (g) and butyl aminomethylphosphonic acid compound (h). After 48 hours or 168 hours (1 week) of incubation at 26-28 ° C, the slides were removed from the bioreactors and placed vertically so that the test surface was evaluated using a stopped procedure. The slides were briefly flamed to fix the cells to the surface and then transferred for one minute to a container of Violet Gram Crystal (DIFCO Laboratories, Detroit, MI). The slides were gently rinsed under running water, carefully dried and again dried with air overnight. The degree of bacterial adhesion was determined by a quantitative evaluation method. Quantitative method of evaluation of bacterial adhesion: The pair of glass slides and the pair of stainless steel slides corresponding to each treatment were each placed in a Petri dish with 10 mL of ethanol (technical) to remove the crystal violet dye. the cells attached to the slides. An aliquot of 1 mL of a crystal violet ethanol solution obtained in a Petri dish was each transferred to a test tube with 9 mL of sterile deionized water (1/10 dilution). The control for the calibration of the optical instrument used for the evaluation was a solution of 1 mL of ethanol in 9 mL of sterile deionized water. The absorption (ABS) of each solution was determined using a spectrophotometer (Spectronic 21, Bausch and Lomb) with a wavelength of 586 nm-. The inhibition of bacterial adhesion (IBA) was calculated as follows: IBA = 100 ((ABS control - ABS treatment) \ ABS control) 90 or > 90% IBA = essentially without bacterial adhesion 89-70% IBA = scarce 69-50% IBA = mild 49-30% IBA = moderate 29- < 29% IBA = moderate Compounds that exhibited 50% of the IBA or greater than that, are considered effective to prevent adhesion of bacteria to submerged slides. The results are shown in the following Table II. Table II: 1 Minimum inhibitory concentration (MIC) for each compound against E. Aerogene bacteria using an 18-hour test of Basic Salts with a pH of 6 and a pH of 8. * SS = stainless steel Although particular embodiments of the invention were described, it is understood, of course, that the invention is not limited to these modalities. Other modifications can be made. The appended claims seek to cover any of these modifications as long as they fall within the true spirit and scope of this invention.

Claims (29)

1. CLAIMS 1. A method for inhibiting the adhesion of bacteria to a submersible surface characterized in that it comprises the step of contacting the submergible surface with aminomethylphosphonic acid or a salt thereof in an amount effective to inhibit the adhesion of the bacteria to a surface submersible, wherein the aminomethylphosphonic acid is a compound of the formula R1R2NCH2P (0) (OH) 2, wherein R1 and R2 are independently, a C6-C20 alkyl group or a CH2P (0) (OH) - But group, R1 and R2 are not both a CHP (0) (OH) 2 group; or R1 and R2 together with N form a 5-8 membered heterocyclic ring having the formula: wherein X is 0, NH, or CH2; and wherein the salt or aminomethylphosphonic acid is an acid salt or a quaternized amino methyl phosphonic acid salt.
2. 2. The method of compliance with the claim 1, characterized in that the so-called contact passage comprises contacting the submergible surface with the aminomethylphosphonic acid or the salt thereof before immersing the submergible surface in an aqueous system.
3. 3. The method according to claim 1, characterized in that R 1 is a C 8 -C 8 alkyl and R 2 is a CH 2 P (0) (0H) 2 group.
4. 4. The method according to claim 1, characterized in that R1 and R2 are each an alkyl group of CB-CIB.
5. 5. The method according to claim 1 characterized in that R1 and R2, together with N, form a 5-8 membered heterocyclic ring.
6. 6. The method of compliance with the claim 1, characterized in that the aminomethylphosphonic acid is hexyl aminomethylphosphonic acid; octyl aminomethylphosphonic acid; decyl aminomethylphosphonic acid; dodecyl aminomethylphosphonic acid; octadecyl aminomethylphosphonic acid; dioctyl aminomethylphosphonic acid; morpholino aminomethylphosphonic acid or a mixture thereof.
7. The method according to claim 6, characterized in that the submersible surface is a boat hull, a boat hull, a marine structure, a tooth surface, the surface of a medical implant or the surface of an aqueous system.
8. 8. A method for controlling biofouling in an aqueous system characterized in that it comprises the step of adding to the aqueous system an aminomethylphosphonic acid or a salt thereof in an amount effective to inhibit the adhesion of bacteria on a submerged surface within an aqueous system, wherein the aminomethylphosphonic acid is a compound of the formula R1R2NCH2P (0) (0H) 2, wherein R1 and R2 are independently a C6-C20 alkyl group or a group CH2P (0) (OH) 2, but, R1 and R2 are not both a CH2P (0) (0H) 2 group; or R1 and R2, together with N, form a 5-8 membered heterocyclic ring having the formula: wherein X is 0, NH, or CH2; and wherein the salt or aminomethylphosphonic acid is an acid salt or a quaternized amino methyl phosphonic acid salt.
9. 9. The method according to claim 8, characterized in that R1 is a Cs-Cis alkyl and R2 is a CH2P (0) (0H) 2 group.
10. 10. The method according to claim 8, characterized in that R1 and R2 are each a C8-C? 8 alkyl group.
11. The method according to claim 8, characterized in that R1 and R2, together with N, form a 5-8 membered heterocyclic ring having the above formula.
12. 12. The method in accordance with the claim 8, characterized in that the aminomethylphosphonic acid is a hexyl aminomethylphosphonic acid; octyl aminomethylphosphonic acid; decyl aminomethylphosphonic acid; dodecyl aminomethylphosphonic acid; octadecyl aminomethylphosphonic acid; dioctyl aminomethylfosphonic acid; morpholine aminomethylphosphonic acid or a mixture thereof.
13. The method according to claim 8, characterized in that the effective amount of the aminomethylphosphonic acid ranges from 10 ppm to 500 ppm.
14. The method according to claim 8, characterized in that the addition step comprises the addition of sufficient aminomethylphosphonic acid to the aqueous system to reduce any biofouling existing in the aqueous system.
15. 15. The method according to claim 8, characterized in that the aqueous system is an industrial water system chosen from a water cooling system, a fluid system for working metals, a system for making paper and a water system for textile manufactures.
16. 16. The method of compliance with the claim 8, characterized in that the aqueous system is a water system for recreation selected from a pool for swimming, fountains, ornamental pond, an ornamental pool or an ornamental brook.
17. 17. The method according to claim 8, characterized in that the aqueous system is a system of sanitary waters from which a bathing water system, a cistern water system, a septic system, and a water system were chosen. sewage treatment.
18. 18. The method according to claim 8, characterized by a greater understanding of the step of adding an effective amount of a biocide to the aqueous system to control the growth of the microorganisms in the aqueous system.
19. 19. The method according to claim 18, characterized in that the biocide is added before the aminomethylphosphonic acid to substantially reduce any biofouling existing in the aqueous system and the aminomethylphosphonic acid is added to prevent the adhesion of surviving bacteria to the submerged surface inside. of the aqueous system.
20. The method according to claim 18, characterized in that the biocide is added together with the aminomethylphosphonic acid.
21. 21. The method according to claim 18, characterized in that the microorganisms are chosen from among algae, fungi and bacteria and the aqueous system is chosen from an industrial water system, a water system for recreation and a water system healthy.
22. 22. A composition for controlling biofouling in an aqueous system, characterized in that it comprises at least one aminomethylphosphonic acid or a salt thereof in an amount effective to inhibit the adhesion of bacteria to a submergible surface or to a submerged surface within the aqueous system, wherein aminomethylphosphonic acid is a compound of the formula R1R2NCH2P (O) (OH) 2, wherein R1 and R2 are independently a C6-C20 alkyl group or a CH2P (0) (0H) 2 group, but, R1 and R2 are not both a CH2P (0) (OH) 2 group; or R1 and R2, together with N, form a 5-8 membered heterocyclic ring having the formula: wherein X is O, NH, or CH2; and wherein the salt of the aminomethylphosphonic acid is an acid salt or a quaternized amino methyl phosphonic acid salt.
23. 23. A composition according to claim 22, characterized in that R1 is an alkyl of C8-Ci8 and R2 is a CH2P (0) (OH) 2 group.
24. 24. The composition according to claim 22, characterized in that R1 and R2 are each a C8-C? 8 alkyl group.
25. 25. The composition according to claim 22, characterized in that R1 and R2, together with N, form a 5-8 membered heterocyclic ring.
26. 26. The composition according to claim 22, characterized in that the aminomethylphosphonic acid is a hexyl aminomethylphosphonic acid; octyl aminomethylphosphonic acid; decyl aminomethylphosphonic acid; dodecyl aminomethylphosphonic acid; octadecyl aminomethylphosphonic acid; dioctyl aminomethylphosphonic acid; morpholino aminomethylphosphonic acid or a mixture thereof.
27. The composition according to claim 26, further characterized in that it comprises a biocide in an amount effective to control the growth of microorganisms in the aqueous system.
28. 28. The composition according to claim 22, characterized in that the composition is in liquid form.
29. 29. The composition according to claim 22, characterized in that the composition is in solid form. SUMMARY The invention relates to a method for inhibiting the adhesion of bacteria to a submergible surface. The method contacts the submergible surface with an effective amount of at least one aminomethylphosphonic acid or salt thereof to inhibit bacterial adhesion to the submergible surface. The invention also relates to a method for controlling the biofouling of an aqueous system. This method adds an effective amount of at least one aminomethylphosphonic acid or salt thereof to inhibit adhesion of the bacteria to the submerged surface within the aqueous system. This method effectively controls biofouling without substantially killing the encrusting organisms. The aminomethylphosphonic acid used in the methods of the invention has the formula R1R2NCH2P (0) (OH) 2- In this formula, R1 and R2 are independently a C6-C2o alkyl group or a CH2P (0) (OH) 2 group- However, R1 and R2 are not both a CH2P (0) (OH) 2 group. Alternatively, R1 and R2 , together with N, form a 5-8 membered heterocyclic ring having the formula (a). In the heterocyclic ring, X is O, NH, or CH2. The salt of an aminomethylphosphonic acid can be an acid salt or a quaternized amino methyl phosphonic acid salt. The invention also relates to a composition having aminomethylphosphonic acids or salts thereof and which is used in the previous methods. The compositions comprise at least one aminomethylphosphonic acid or salt thereof in an amount effective to inhibit the adhesion of the bacteria to submergible or submerged surfaces.