MXPA06008728A - Antifouling coating composition and its use on man made structures - Google Patents

Abstract

Antifoulding coating composition comprising 20-100%by weight, calculated on the total amount of film-forming components, of a film-forming polymer (A) having an acrylic backbone bearing at least-one terminal group of the formula (I), wherein X represents (II), M is a metal of Group Ib, IIa, IIb, IIIa, IIIb, Iva, Ivb, Va, Via, VIb, VIIa, and VIII of the Periodic Table with a valency of 2 or more and a degree of ionization less than that of the alkali metals metal;n is an integer of 1 to 2;R represents an organic residue selected from (III), and R1 is a monovalent organic residue, and 80-0%by weight, calculated of polymer (B) a copper-based biocide for aquatic organisms characterized in that that the antifoulding coating composition is substantially free of any biocidal zinc compounds and substantially free of rosin, and in that the copper-based biocide has a metallic copper content below 2%by weight, based on the total weight of the copper-based biocide.

Description

COMPOSITION OF ANTI-INCRUSTING LAYER AND ITS USE IN STRUCTURES MADE BY MAN DESCRIPTIVE MEMORY The invention relates to an anti-fouling layer composition, with good storage properties which is suitable as a layer for man-made structures submerged in an aquatic environment, independently of the salinity thereof. Human-made structures such as ship hulls, bowls, drilling platforms, oil rigs, and pipes that are submerged in water are prone to fouling through aquatic organisms such as green algae and coffee, limpets, mussels, and similar. Said structures are commonly made of metal, but may also comprise other structural materials such as wood, fiberglass or concrete. These incrustations are a nuisance to the hulls of ships, because they increase the resistance to friction during the movement through the water, the consequence being reduced speeds and increased fuel costs. It is a nuisance for static structures such as the legs of drilling platforms and oil platforms, primarily due to the resistance of coarse layers of scale to waves and currents can cause non-predictable and potentially dangerous stresses in the structure and, in secondly due to the incrustations that make it difficult to inspect the structure for defects such as stress rupture and corruption. It is a nuisance in the pipes such as cooling water inlet and outlet connections, because the effective cross-sectional area is reduced through the incrustations, with the consequence that the flow rates are reduced. A composition with an anti-fouling layer will generally be applied as an upper layer in the submerged areas of the structure to inhibit the settlement and growth of aquatic organisms such as limpets and algae, generally through the release of a biocide for aquatic organisms. Traditionally, anti-fouling coating compositions have comprised a relatively inert binder with a biocidal pigment that is washed away from the coating composition. Among the binders that have been used are vinyl resins, and dry tar or dry tar derivatives. Vinyl resins are water insoluble and layer compositions based on the use of a high concentration of pigment to have contact between the pigment particles to ensure washout. Dry tar is a hard brittle resin that is very slightly soluble in water. Compositions with anti-fouling coating based on dry pitch have been referred to as soluble matrix or erodible coating compositions. The biocidal pigment is very gradually washed out of the matrix of the dry pitch binder in use, leaving a matrix of dry pitch basic structure, which is washed away from the surface of the hull to allow the biocidal pigment to wash off from the depth inside. the layer composition film. Many successful antifouling compositions in recent years have been "self-polishing copolymer" coating compositions based on a polymeric binder to which the biocidal tri-organotin portions are chemically bonded from which the portions of biocide gradually hydrolyze in an aquatic environment. In such binder systems, the side groups of a linear polymer unit are divided in a first step through the reaction of the aqueous medium, the structure of the polymer that remains soluble in water, or dispersible in water as a result. In a second step, the water-soluble or water-dispersible structure on the surface in the layer of the ship's layer composition is washed or eroded. Such layer composition systems are described for example in GB-A-1 457 590. Since the use of tri-organotin has been banned around the world, there is a need for alternative anti-fouling substances that can be used in anti-fouling compositions. Self-polishing copolymer layer compositions, which release non-biocidal portions are described in EP-A-69 559, EP-A-529 693, WO-A-91/14743, WO-A-91/09915, GB -A-231 070, and JP-A-9-286933. Various compositions are described with self-polishing polymer layer that release non-biocidal portions for example in EP-A-2004 and EP-A-779 304. The binder used in the layer compositions comprises an acrylic structure bearing at least one terminal group of the formula: - X- -O-M-R esenta O fj o Q where X repr p or ll ^ - C- - c- - p- - P \ M is a metal selected from, for example, zinc, copper, and Tellurium, n is an integer from 1 to 2; R represents an organic waste selected from: _5_U_R1 or-C-R1-0-C-R1 '- 0-R1 - S-R1 0; and R1 is a monovalent organic residue.

Usually, the binder is mixed with a biocide for the aquatic organisms. Commercially successful antifouling compositions of this type most commonly comprise a binder wherein X is o, M is copper, R represents o - C - - -0-C-R1 and the binder is mixed with cuprous oxide and a zinc compound biocide such as zinc pyrithione. More recently, antifouling compositions have been developed wherein the binder comprises a dry pitch material and an auxiliary film-forming resin, the auxiliary film-forming resin comprises an acid functional film-forming polymer, whose acid groups are blocked by groups capable of hydrolyzing, dissociating, or exchanging with seawater species to leave a fresh water soluble polymer and optionally a portion of the film-forming polymer insoluble in the non-hydrolysable water. Said layer compositions are described in WO 02/02698. However, although antifouling coat compositions with acceptable properties are known in the art, there is still a need for products with improved properties. In the first place, it has been found that there is a need for a layer composition with a long-term storage stability increased in liquid state (shelf life). Additionally, there is a need for an anti-fouling layer composition that can work well in all aqueous environments, regardless of salinity. This will be clarified below. It is a common practice in the marine construction industry for boats and other objects by man that are going to be made on land, or on a dry dock floating and then thrown or floated after the completion of the structure of man . The manufacture of the ship or other man-made object can then be completed and the structure is equipped while it is submerged in an aquatic environment. In many countries, for example, in Europe, such as Romania, or in China, boats and other man-made objects are usually thrown in a low salinity or fresh water aquatic environment such as the Baltic Sea, or a river or river estuary. Many of these structures will subsequently find a seawater environment or other aquatic environment with higher salinity during normal operation. In some cases, the structure will find changes in salinity of the aquatic environment, for example, when a ship regularly travels between a river or a river estuary and into the ocean. It has been found that antifouling coat compositions that work well in seawater or in a high salinity aquatic environment do not necessarily work well, and can still work very poorly, in fresh water, or in a low aquatic environment. salinity. For example, the commercially successful anti-fouling coating compositions discussed above, comprising a binder wherein X is -C = O, M is copper, R represents -COO-R1, in combination with cuprous oxide and a biocide zinc compound such as zinc pyrithione generally have excellent and durable physical and mechanical properties when immersed in salt water or a brackish aquatic environment when they have been found to exhibit excessive softening, rupture, blistering or delamination by exposure to fresh water or an aquatic environment with low salinity. For another example, the compositions with anti-fouling coating based on dry pitch described in WO 02/02698 have poorer physical and mechanical properties after immersion in fresh water or a low salinity aquatic environment than in a seawater or a seawater. aquatic environment with high salinity. Additionally, compositions with a dry tar-based coating generally show lower persistent antifouling performance to compositions with a self-polishing anti-fouling layer free of dried pitch. Surprisingly it has been found that an anti-fouling layer composition that combines good long-term storage stability in the liquid state (shelf life) with the ability to function well in all aqueous environments, regardless of salinity, can be achieve through the selection of a specific biocide with a specific metallic metal content, where the composition should be free of biocidal zinc compounds and dry pitch. Accordingly, the present invention pertains to an anti-fouling layer composition comprising: 20-100% by weight, calculated on the total amount of film-forming components, of a film-forming polymer (A) having a structure Acrylic that carries at least one terminal group of the formula: - -YO-M-R jp O O O II wherein X represents - C - ^ - C- (- P - or \ M is a metal of group Ib, Na, llb, Illa, lllb, IVa, IVb, Va, Via, Vlb, Vlla and Vlll of the Table Periodic with a valence of 2 or more and a degree of ionization lower than that of the metal of the alkali metals; n is a whole from 1 to 2; R represents an organic residue selected from: s O s II II II • S-C-R1 - - 0 ~ C- R1 - - O-C- R1 -0-R1 -S- 1 O and R1 is a monovalent organic residue, and 80-0% by weight, calculated on the total amount of film-forming components, of polymer (B) selected from polymers that are free from the groups terminals X- [O-M-R] n and that react in water, slightly soluble in water, or sensitive to water, or insoluble in water. a copper-based biocide for aquatic organisms characterized in that the anti-fouling layer composition is substantially free of any biocide compound and substantially free of dry resin and in which the copper-based biocide has a content of metallic copper below 2% by weight, based on the total weight of the copper-based biocide. M is a metal of group Ib, lia, llb, Illa, lllb, IVa, IVb, Va, Via, Vlb, Vlla and Vlll of the Periodic Table with a valence of 2 or more and a degree of ionization lower than that of the metal of the alkali metals. The use of one or more of Ca, Mg, Zn, Cu, Te, Ba, Pb, Fe, Co, Ni, Si, Ti, Mn, Al, Bi, and Sn is preferred. The use of one or more of Cu, Zn, and Te is more preferred, with the use of one or more of Cu and Zn being even more preferred, and the use of Cu being particularly preferred.

Preferably, the film-forming polymer (A) is a acrylic polymer where X represents fl - c- -, M is copper and R represents. -0_j? _R1. The main acrylic polymer having a -COOH group instead of -X- [O-M-R] x preferably it has an acid value of 25-350 mg KOH / g. Said hydrolysable polymers can be prepared through the processes of EP-A-204456 and EP-A-342276. More preferably the hydrolysable polymer has a copper content of 0.3-20% by weight. The copper-containing film-forming polymer (A) is preferably a copolymer comprising a methacrylic acrylic ester whose alcohol residue includes a bulky hydrocarbon radical or a soft segment, for example, a branched alkyl ester having 4 or more carbon atoms. carbon or a cycloalkyl ester having 6 or more atoms, a polyalkylene glycol monoacrylate, or monometacriiate optionally having a terminal alkyl ether group or a 2-hydroxyethyl acrylate adduct methacrylate with caprolactone, as described in EP-A-779304. It is preferred that R is the residue of an organic monobasic carboxylic acid having a boiling point greater than 115 ° C, and an acid value between 50 and 950 mgKOH / gram. There is no upper limit at the boiling point and R may be the residue of a substantially non-volatile acid. The material will generally have a boiling or decomposition temperature below 500 ° C. The organic monobasic carboxylic acid can be referred to as a high boiling acid. The acid may be aliphatic, aromatic, linear, branched, alicyclic or heterocyclic. It is particularly preferred that R is the residue of one or more of the following acids: benzoic acid, salicylic acid, 3,5-dichlorobenzoic acid, lauric acid, stearic acid, nitrobenzoic acid, linoleic acid, ricinoleic acid, 12-hydroxystearic acid, Fluoroacetic acid, Pulvic acid, O-cresotinic acid, naphthol-1-carboxylic acid, p-oxy-benzoic acid, chloroacetic acid, dichloroacetic acid, naphthenic acid, p-phenylbenzoic acid, lithocholic acid, phenoxyacetic acid, 2,4- dichlorophenoxyacetic acid, oleic acid, versatic acid, nicotinic acid, penicillic acid, and the like, or a diterpenoid acid having a basic structure of abietane, pimarane, isopyramine, or labadane such as for example, abietic acid, neoabietic acid, levopimaric acid, dextropimary acid, sandaracopimaric acid, and the like, which can be used individually or in combination. The film-forming polymer (A) is generally present in the layer composition in an amount of at least 3% by weight, preferably at least 6% by weight, more preferably at least 10% by weight. It is generally present in an amount of at most 60% by weight, preferably at most 50% by weight, more preferably at most 45% by weight. The film-forming polymer (A) can also be a so-called high solids resin. By using said resin, a layer composition with a volatile organic compound (VOC) content of not more than 400 g / l, preferably at least 360 g / l, can be obtained. The film-forming polymer (A) can be prepared as follows: i) The polymerization of an unsaturated organic acid monomer and an unsaturated monomer and either through the reaction of the resulting acrylic resin with a metal compound and a monobasic acid or through the reaction of said acrylic resin with a metal salt or a monobasic acid or ii) React an unsaturated organic acid monomer with a metal compound and a monobasic acid or through the reaction of an organic acid monomer unsaturated with a metal salt of a monobasic acid and polymerizing the unsaturated monomer containing the resulting metal with another unsaturated monomer. In view of the highest performance method, i) is preferred. The aforementioned unsaturated organic acid monomer can be selected from the group of unsaturated compounds having at least one carboxyl group, for example, unsaturated monobasic acids such as (meth) acrylic acid; unsaturated dibasic acids and monoalkyl esters thereof, such as maleic acid including its monoalkyl esters and itaconic acid inclusive of its monoalkyl esters; unsaturated monobasic acid hydroxyalkyl ether-dibasic acid adducts, such as 2-hydroxyethyl (meth) acrylate-maleic acid adduct, 2-hydroxyethyl (meth) acrylate-phthalic acid adducts, and (meth) acrylate -hydroxyethyl-succinic acid adduct. In this specification the term (meth) acrylic acid is used to mean either methacrylic acid and acrylic acid. The additional unsaturated monomer can be selected from several esters of (meth) acrylic acid, for example, alkyl (meth) acrylates, ester portions which can contain from 1 to 20 carbon atoms, such as methyl (meth) acrylate. , ethyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, (meth) acrylate -ethylhexyl, lauryl (meth) acrylate and stearyl (meth) acrylate; hydroxy-containing alkyl (meth) acrylates, the ester portions which contain from 1 to 20 carbon atoms, such as 2-hydroxypropyl (meth) arylate and 2-hydroxyethyl (meth) acrylate; cyclic hydrocarbon esters of (meth) acrylic acid, such as phenyl (meth) acrylate and cyclohexyl (meth) acrylate; esters of polyalkylene glycol of (meth) acrylic acid, such as polyethylene glycol mono (meth) acrylate and polyethylene glycol mono (meth) acrylate with a degree of polymerization in the range of 2 to 50; C 1-3 alkoxyalkyl (meth) acrylate; (meth) acrylamide; vinyl compounds such as styrene, alpha-methylstyrene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl toluene, and acrylonitrile; proton acid esters; and diesters of unsaturated dibasic acids, such as diesters of maleic acid and diesters of itaconic acid. Of the aforementioned (meth) acrylic acid esters, the ester portions are preferably alkyl groups containing from 1 to 8 carbon atoms, more preferably alkyl groups containing from 1 to 6 carbon atoms. Preferred specific compounds are methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cyclohexyl (meth) acrylate. The aforementioned unsaturated organic acid monomers and other unsaturated monomers each may be used alone or in a combination of two or more species. The film-forming polymer (A) preferably has an acid value of 25 to 350 mg KOH / g. If the acid value is below 25 mg KOH / g, the amount of the metal salt to be bonded to the side chain is too low for effective anti-fouling and self-polishing properties. If it is above 350 mg KOH / g, the degree of hydrolysis will be too high so that the service life of the antifouling layer is strongly reduced. In addition, said high acid value will result in the viscosity raising of the film-forming polymer (A), which could make it less suitable for use in low VOC layers. An acid value is on the scale of 100 to 250 mg KOH / g is preferred. The antifouling layer comprises a copper-based biocide for aquatic organisms having a metallic copper content below 2% by weight, based on the total weight of the copper-based biocide. Preferably, the metallic copper content is below 1% by weight, more preferably below 0.8% by weight and even more preferably below 0.75 by weight. If the copper-based biocide has a metallic copper content of more than 2% by weight, the object of the present invention is not achieved. The copper-based biocide for aquatic organisms with a low metallic copper content is generally present in an amount of at least 1% by weight, preferably at least 5% by weight, more preferably at least 10%, still more preferably at least 25% by weight, based on the total weight of the layer composition, the copper-based biocide is generally present in an amount of at most 75% by weight, preferably at most 70% by weight, even more preferably at much 60% by weight based on the total weight of the layer by weight composition. Examples of copper-based biocides for aquatic organisms include cuprous oxide, cuprous thiocyanate, cuprous sulfate, or copper pyrithione. These copper-based biocides can be used alone or in a mixture of two or more of these compounds. In view of the good physical properties and overall anti-fouling, cuprous oxide with a low metal content is the preferred copper-based biocide for use in the antifouling layer composition according to the present invention. Since cupric oxide is usually present as an impurity in cuprous oxide, the layer composition may contain an amount of cupric oxide of up to 10% by weight, preferably up to 6% by weight, more preferably up to 3% by weight , based on the total weight of cuprous oxide. In a further preferred embodiment, the anti-fouling layer composition according to the present invention comprises a cuprous oxide mixture having a metal copper content below 2% by weight, and copper pyrithione. In this case, the cuprous oxide is preferably present in an amount of 20-60% by weight, and the copper pyrithione is preferably present in an amount of 1-15% by weight. As indicated above, the layer composition of the present invention is substantially free of biocide zinc compounds and substantially free of dry pitch. If this requirement is not met, the advantageous effects of the present invention are not obtained. In the context of the present invention the substantially free indication means that the component in question is not present in such an amount that the properties of the layer composition are adversely affected. For the present application this means that the layer composition comprises less than 1% by weight of dry pitch and less than 1% by weight of the biocide zinc compounds, more preferably the layer composition comprises less than 0.1% by weight of dry pitch and less than 0.1% by weight of zinc biocide compounds, the weight percentage being calculated based on the total content of the coating composition. Within the structure of the present application, the biocidal zinc compound is a zinc compound that is used in an antifouling composition to provide a biocidal effect on aquatic fouling organisms. A polymer containing Zn (A) is not a biocidal Zn compound within the structure of the present invention. For a good order it is observed that in the context of the present specification the dry pitch-free wording means free of dry pitch, ie, free of dry pitch not bound to polymer (A) or polymer (B). The presence of free dry pitch leads to a reduction in the operation of the compositions with anti-fouling layer. The layer composition preferably has a pigment volume concentration of, for example, 15 to 55%, defined as the ratio, expressed as a percentage, of the total pigment volume and / or the perceivers and / or other solid particles in the composition. product to the total volume of non-volatile matter. In addition to the copper-based biocide for aquatic organisms having a metallic copper content below 2% by weight, the anti-fouling layer compositions according to the present application optionally comprise an additional ingredient having biocide properties for aquatic organisms . In addition, the compositions with anti-fouling layer may comprise one or more non-biocidal pigments, and / or additives such as one or more thickening or thixotropic agents, one or more wetting agents, plasticizers, a liquid carrier such as an organic solvent, non-organic solvent or water, etc., all as are conventional in the art. In addition to the film-forming polymer (A), the anti-fouling layer composition according to the present invention optionally comprises another film-forming polymer (B). The polymer (B), which is present in an amount of 80-0% by weight, calculated on the total amount of film-forming components, is selected from the polymers that are free from the terminal groups -X- [OMR] n but which are reactive in water, slightly soluble in water, sensitive to water, or insoluble in water. Polymers (B) that are selected from non-hydrolyzable, water insoluble film-forming polymers may be preferred. As examples of a suitable polymer (B) which is free from the terminal groups -X - [- O-M-R] n but which are reactive in water, various resins may be mentioned. For example, an example of a suitable polymer is a functional film-forming polymer with acid, the acid groups of which are blocked by quaternary ammonium groups or quaternary phosphonium groups. This is for example described in WO 02/02698. A water-reactive polymer can alternatively be a film-forming polymer comprising quaternary ammonium group and / or linked quaternary phosphonium groups (pendant to the polymer structure.) These quaternary ammonium groups and / or quaternary phosphonium groups are neutralized or, in other words, they are blocked or covered by counterions, said counterions consist of the anionic residue of an acid having an aliphatic, aromatic, or aralkyl hydrocarbon group comprising at least 6 carbon atoms. , described in PCT / EP03 / 007693.A further example of a suitable water-reactive polymer is a silyl ester copolymer comprising at least one side chain bearing at least one terminal group of the formula (I): wherein n is 0 or an integer from 1 to 50, and R1, R2, R3, R4 and R5 are each independently selected from the group consisting of substituted C? -2 alquiloo alkyl, optionally substituted C alco? alco alco alkoxy , optionally substituted aryl, and optionally substituted aryloxy. Preferably, at least one of the groups R1-R5 is the copolymer of silyl ester is methyl, isopropyl, n-butyl, isobutyl, or phenyl. More preferably, n is 0 and R3, R4 and R5 are the same or different and represent isopropyl, n-butyl, or isobutyl. A silyl ester copolymer comprises at least one side chain bearing at least one terminal group of the for described above (I) which can, for example, be obtained through the copolymerization of one or more polymerizable vinyl monomers with one or more monomers comprising one or more olefinic double bonds and one or more of the terminal groups described above (I). Examples of suitable vinyl polymerizable monomers, which may be polymerized with one or more monomers comprise one or more olefinic double bonds, and one or more of the terminal groups described above (I), include esters of (meth) acrylate such as methyl methacrylate. , ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, and methoxyethyl methacrylate; maleic acid esters such as dimethyl maleate and diethyl maleate; esters of fumaric acid such as dimethyl fumarate, and diethyl fumarate; styrene, vinyl toluene, α-methyl styrene, vinyl chloride, vinyl acetate, butadiene, acrylamide, acrylonitrile, (meth) acrylic acid, acrylic acid, isobornyl methacrylate, maleic acid, and mixtures thereof. Preferably, a mixture of methyl (meth) acrylate or ethyl (meth) acrylate with another vinyl polymerizable monomer is used. It is possible to adjust the degree of polish of the layer through the use of a mixture of a hydrophobic (meth) acrylate and a hydrophilic one. Optionally included is a hydrophilic comonomer such as methoxyethyl (meth) acrylate or a higher polyethylene oxide derivative, such as ethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, a monoacyl ether of polyoxyethylene glycol, such as polyoxyethylene monomethyl glycol ether methacrylate (n = 8) or N-vinylpyrrolidone.

Examples of suitable monomers comprise one or more olefinic double bonds and one or more of the terminal groups described above (I), which can be copolymerized with one or more polymerizable vinyl monomers, include monomers comprising one or more terminal groups (I) in where n = 0, and which may be represented by the for (II): R3 X Yes R4 R5 wherein R3, R4, and R5 are as defined above, and X is a (meth) acryloyloxy group and a maleinoyloxy group or a fumaroyloxy group. The preparation of the monomers (II) can, for example, be carried out according to the methods described in EP 0 297 505, or according to the methods described in EP 1 273 589, and the references cited therein. Examples of suitable (meth) acrylic acid-derived monomers include trimethylsilyl (meth) acrylate, triethylsilyl (meth) acrylate, tri-n-propylsilyl (meth) acrylate, triisopropylsilyl (meth) acrylate, (meth) acrylate tri-n-butylsilyl, triisobutylsilyl (meth) acrylate, tri-tert-butylsilyl (meth) acrylate, tri-n-amylsilyl (meth) acrylate, tri-n-hexylsilyl (meth) acrylate, (meth) acrylate of tri-n-octylsilyl, tri-n-dodecylsilyl (meth) acrylate, triphenylsilyl (meth) acrylate, tri-p-methylphenylsilyl (meth) acrylate, tribenzylsilyl (meth) acrylate, dimethylphenylsilyl (meth) acrylate, (meth) dimethylcyclohexyl acrylate, ethyldimethylsilyl (meth) acrylate, n-butyldimethylsilyl (meth) acrylate, t-butyldimethylsilyl (meth) acrylate, diisopropyl n-butylsilyl (meth) acrylate, n-octyldi (meth) acrylate -n-butylsilyl, diisopropylsarylsilyl (meth) acrylate, dicyclohexylphenylsilyl (meth) acrylate, t-butyldiphenylsilyl (meth) acrylate, and lauryldiphenylsilyl (meth) acrylate. Preferably triisopropylsilyl (meth) acrylate, tri-n-butylsilyl (meth) acrylate, or triisobutylsilyl (meth) acrylate is used in the preparation of the silyl ester copolymer. Alternatively, said functional film-forming polymer with water-reactive acid of acidic groups from which it is blocked can be a functional carboxylic acid polymer. For example, it can be a copolymer of acrylic or methacrylic acid with one or more alkyl acrylates or methacrylates, at least some of the acid groups of which have been converted to groups of the formula -COO-M-OH, wherein M it is a divalent metal such as copper, zinc, calcium, magnesium, or iron, as described in GB 2.31,170. Another example of such functional film-forming polymers with water-reactive acids of the acid groups of which they are blocked is a polymer which is a salt of an amine. Preferably it is an amine salt containing at least one aliphatic hydrocarbon group having from 8 to 25 carbon atoms, and a functional film forming polymer with acid as described in EP 0 529 693, the functional polymer with acid preferably being an addition copolymer of an olefinically unsaturated carboxylic acid, sulfonic acid, acid sulfate ester, phosphoric acid or acid phosphate ester, and at least one olefinically unsaturated co-monomer, the unsaturated carboxylic acid for example being acrylic or methacrylic acid, the unsaturated sulfonic acid for example being 2-acrylamido-2-methylpropane sulfonic acid (AMPS), and the film-forming polymer preferably being an amine sulfonate copolymer containing units of an organocyclic ester as described in WO 99/37723. As an example of a suitable polymer (B) which is slightly soluble or sensitive to water, the following compounds may be mentioned: polyvinyl methyl ether, polyvinyl ethyl ether, alkali resins, modified alkali resins, polyurethanes, saturated polyester resins, and poly-N-vinyl pyrrolidone. As an example of a suitable polymer (B) which is insoluble in water, the following compounds may be mentioned: modified alkyd resins, epoxy polymers, epoxy esters, epoxy urethanes, polyurethanes, linseed oil, castor oil, oil of soybeans, and derivatives of said oils. Other examples of water-soluble polymers or resins are vinyl ether polymer, for example, a poly (alkyl vinyl ether) such as polyvinyl isobutyl ether, or a copolymer of an alkyl vinyl ether with vinyl acetate or vinyl chloride , an acrylate ester polymer, such as a homopolymer or copolymer of one or more alkyl acrylates or methacrylates preferably containing 1 to 6 carbon atoms in the alkyl group and may contain a co-monomer such as acrylonitrile or styrene, and a vinyl acetate polymer such as polyvinyl acetate or a vinyl chloride vinyl acetate copolymer. Alternatively, the polymer insoluble resins in water may be a polyamine, particularly a polyamine having a plasticizing effect such as polyamide of a fatty acid dimer or a polyamide sold under the trade name of "Santiciser". If in addition to the film-forming polymer (A), the layer composition comprises one or more polymers (B), these other polymers can form up to 80% by weight of the total amount of resins in the layer composition. Preferably, the composition contains 0.20% by weight of the polymer (B), calculated on the total resins in the layer composition, to obtain a high quality self-polishing layer. The total amount of the film-forming components present in the layer composition according to the present invention is generally at least 3% by weight, preferably at least 6% by weight, more preferably at least 10% by weight . It is generally at most 60% by weight, preferably at 50% by weight, most preferably at 45% by weight. The layer composition may contain other conventional components used in the art. As an example, suitable plasticizers that can be used in the present invention, the following materials can be exemplified: chlorinated paraffins, aromatic phosphate esters such as triisopopilphenyl phosphate, and phthalate esters such as dioctyl phthalate. These materials can be used individually or in combination. The polymers and other soluble film-forming binder forming components can be mixed in a common solvent forming at least in part the solvent of the layer composition, for example, an aromatic hydrocarbon such as xylene, toluene, or trimethylbenzene, a alcohol such as n-butanol, an ether alcohol such as butoxyethanol, or methoxypropanol, an ester such as butyl acetate or isoamyl acetate, an ether / ester such as ethoxyethyl acetate or methoxypropyl acetate, a ketone such as methyl isobutyl ketone or methyl isoamyl ketone , an aliphatic hydrocarbon such as white alcohol, or a mixture of two or more of these solvents. The layer composition can alternatively be based on water. The anti-fouling layer composition according to the present invention may additionally comprise sparingly soluble pigments having a water solubility of 0.5 to 10 parts per million which are not biocidal for aquatic organisms. Examples of such pigments include zinc oxide, barium sulfate, calcium sulfate, and dolomite. Moderately soluble biocide or non-biocidal pigments can be used, for example, cuprous oxide, copper thiocyanate or copper pyrithione which are highly effective as biocidal pigments, can optionally be mixed with a non-biocidal soluble pigment such as zinc oxide. In addition to copper-based biocides for aquatic organisms having a low metallic copper content, the antifouling composition may contain one or more non-metalliferous biocides for aquatic organisms, i.e., an ingredient having aquatic biocidal properties that is a biocide, but that may or may not be a pigment. Examples of compounds are tetramethyl thiuram disulfide, methylene bis (thiocyanates), captan, pyridium triphenylboron, a substituted isothiazole such as 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 2-methylthio- 4-t-butylamino-6-cyclopropylamino-s-triazine, n-3,4-dichlorophenyl-N ', N'-dimethyl-urea ("Diuron"), 2- (thio-cyanomethylthio) benzothiazoi, 2,4, 5,6-tetrachloro-isophthalonitrile, dichlorofluanide, tolifluanido, 2- (p-chlorophenyl) -3-cyano-4-bromo-5-trifluoromethyl pyrrole, 3-butyl-5- (dibromomethylidene) -2 (5H) -furan 3 - (benzo (b) thien-2-yl) -5,6-dihydro-1, 4,2-oxathiazine-4-oxide, L-menthol, 5-methyl-2- (isopropyl) -cyclohexanol, isoproturon , tiavenzadolo, dodecilguanidina monohydrochloride, chlorotoluron, cic-4- [3- (p-tert-butylphenyl) -2-methylpropyl] -2,6-dimethylmorpholine, fluometuron, folpet, prometryn, chlorophenapyr, n-octyl disulfide chloromethyl and 2, 3,5,6-tetrachloro-4- (methylsulfonyl) pyridine. Optionally, the anti-fouling composition comprises one or more acid-functional biocides, for example (9E) -4- (6,10-dimethylocta-9,11-dienyl) furan-2-carboxylic acid and p- ( sulfa-oxy) cinnamic (zosteric acid) or a quaternary ammonium compound such as cetylpyridinium chloride.

Many of these non-metalliferous biocides are solid and all are moderately soluble in water and can assist the "self-polishing" action of the coating composition. The layer composition may additionally contain a pigment which is not reactive with water and may be highly water soluble (solubility below 0.5 parts per million by weight) such as titanium dioxide or ferric oxide, or an organic pigment such as phthalocyanine or azo pigment. Said highly insoluble pigments are preferably used in less than 60% by weight of the total pigment component of the layer composition, more preferably less than 40%. The layer composition may additionally contain conventional binders, particularly thixotropes such as silica, bentonite, or polyamide wax and / or stabilizers, for example, zeolites, or aliphatic or aromatic amines such as dehydroabietylamine. The layer composition of the present invention is usually applied as a top layer. As such it can be applied in the normal coating scheme for a newly constructed vessel. However, it is also possible to use it as a top cover in the maintenance and repair of existing containers and it can also be applied as a top layer on a cover layer containing biocide material and / or a dry pitch. Within the structure of the present application, a seawater aquatic environment is an aquatic environment that has a salinity of approximately 35 practical salinity units (psu, a unit that is based on conductivity measurements), an aquatic environment of High salinity is an aquatic environment that has a salinity of between 15 and 35 psu, a low salinity aquatic environment is an aquatic environment that has a salinity of less than about 15 psu, and a freshwater aquatic environment is an aquatic environment that contains less than about 1000 mg / liter of the total dissolved solids. Examples of low salinity aquatic environments are river estuaries, and semi-enclosed marine environments, with high inputs of fresh water and restricted exchange with seawater, such as the Baltic Sea. Examples of fresh water aquatic environments are rivers, lakes, and other surface waters.

EXAMPLES Manufacture of compositions A to G The following materials were mixed in stipulated parts by weight in a high speed dispenser to prepare the compositions with anti-fouling layer: The film-forming resin X is an acrylic acid copolymer substantially in accordance with Production Example 1 of EP0779304-A1, wherein the acrylic acid units are blocked through the copper bond with the naphthenic acid residues. The copper-based biocide A is a cuprous oxide pigment having a metallic copper content of 2.7% by weight, the copper-based biocide B is a cuprous oxide pigment having a metallic copper content of 0.6% by weight; The copper-based biocide C is a copper pyrithione pigment essentially free of metallic copper. Biocide A based on zinc is a pigment of zinc pyrithione. The solvent was a mixture of xylene, butanol, methyl isobutyl ketone and butoxypropanol, and the film-forming resin A was prepared in a solvent before mixing with the other components of the coating composition. In the foregoing, the layer composition A is according to the invention, while the layer compositions B to G are comparative.

EXAMPLE 1 The effect of the metallic copper content in the copper biocide Individual 250 ml containers were filled with the layer composition A and the layer composition B, the containers were sealed and placed in a storage oven at 45 ° C, and the stability of the layer compositions was periodically monitored. After 1 month, the layer composition B exhibited a high settling and agglomeration of pigments and the layer composition was no longer suitable for application. By contrast, the layer composition A showed only a slight settling of pigments after 6 months. The settled pigment was easily redispersed through filtration with a spatula and the layer composition was still suitable for the application. This result demonstrates that the antifouling composition has a metallic copper content below 2% by weight based on the total weight of the copper-based biocide having improved storage stability.

EXAMPLE 2 The effect of biocidal zinc compounds on the performance of fresh water (a) Fresh water softening The test layers were prepared through the casting of the separated layer compositions A, C, D, E and F in degreased glass panels (approximately 15 cm x 10 cm) using an applicator. bar. The layer films were dried under ambient conditions before the test. The hardness of the layer was subsequently determined by the Kónig pendulum wetting method in ISO 1522. The hardness was quantified as the number of oscillations of the pendulum to moisten from 6o to 3o. The layers were then immersed in fresh water at 23 ° C for 21 days and the hardness was re-determined immediately upon removal of the water and before the layer dried. The results are shown in the following table. (b) Water Absorption The test layers were prepared through the casting of the layer compositions A, C, D, E and F on pre-weighed degreased glass plates (approximately 2 cm x 5 cm) using an applicator. of cube The layer films were dried under ambient conditions and the dry coated plates were weighted to determine the weight of the applied layer composition film. The coated plates were then immersed in fresh water at 23 ° C for 7 days. The platens were then reweighed immediately after removal of the water and after the layer was dried to determine water absorption, expressed as a percentage of the original weight of the dried film. The results are shown in the following table: These results show that the presence of the zinc-based biocide has a detrimental effect on the film properties of the layer compositions when immersed in a fresh water environment and leads to excessive water absorption and undue softening of the layer .

EXAMPLE 3 Effect of the presence of copper pyrithione As a proof of anti-fouling performance, the layer composition A and layer composition C were applied to laminated wood boards that had been coated with a commercial anti-corrosive base paint and the boards were immersed in natural water in the Yealm River in Newton Ferrers, Devon, England; the River Crouch at Bumham-on-Crouch, Essex, England; and Johor Strait at Changi, Singapore. The films of the layer composition were periodically evaluated for the settlement of fouling organisms and evaluated on a scale of 0 to 100, where 0 indicates a severe settling and the growth of soft and hard modalized animals, algae and lama covering the film of full layer composition, and 100 indicates the layer composition film is free of inlays. The results are shown in the following table.

These results show that the layer compositions of the present invention exhibit superior antifouling performance when copper pyrithione is included in the formulation.

EXAMPLE 4 The effect of biocidal zinc compounds on the operation of salt water The test layers were prepared by melting the layer compositions A and F on separate degreased glass panels (approximately 15 x 10 cm) using a bar applicator. The layer films were dried under ambient conditions before the test. The hardness of the layers was subsequently determined by the Kónig pendulum wetting method described in ISO 1522. The hardness was quantified as the number of oscillations of the pendulum to moisten from 6a to 3a. The layers were then immersed in seawater at 23 ° C for 14 days and the hardness was determined again immediately after the removal of the water and before the coating dried. The results are shown in the following table: The results show that, in contrast to the results of immersion in the fresh water environment, the presence of the zinc based biocide does not have a detrimental effect on the film properties of the layer compositions when immersed in an environment of seawater and do not lead to undue softening of the layer.

EXAMPLE 5 Additional embodiments of the present invention The following materials were mixed in stipulated parts by weight in a high-speed dispenser to prepare the antifouling layer compositions: The film-forming resin Y is a copolymer of acrylic acid substantially equivalent to the film-forming resin X in which the acrylic acid units are blocked through the zinc bond for naphthenic acid acids. Copper-based biocide D is a cuprous acid pigment having a metallic copper content below 0.001% by weight. Copper-based biocide E is a copper thiocyanate pigment which is essentially free of metallic copper.

Water Absorption The measurement of water absorption was carried out for layer composition H, I, and J as described in Example 2 (b).

These results further illustrate the utility of the layer compositions of the present invention.

Claims (13)

NOVELTY OF THE INVENTION CLAIMS

1. - An anti-fouling layer composition comprising: 20-100% by weight, calculated on the total amount of film-forming components, of a film-forming polymer (A) having an acrylic structure bearing at least one terminal group of the formula: -OR- -R where X represents o¡j o | o ^ II II H - c - t - c - f ~~ PM is a metal of group Ib, lia, llb, Illa, lllb, 'IVa, IVb, Va, Via, Vlb, Vlla and Vlll of the Table Periodic with a valence of 2 or more and a degree of ionization lower than that of the metal of the alkali metals; n is an integer from 1 to 2; R represents an organic waste selected from: s or s - S-C-R 1 O-C-R 1 - 0-C-R 1 '- 0-R 1 - S-R 1 < I I J O ; and R1 is a monovalent organic waste, and 80-0% by weight, calculated on the total amount of the film-forming components, of polymer (B) selected from polymers that are free from the terminal groups X- [OMR] ny that react in water, slightly soluble in water, or sensitive to water, or insoluble in water; a biocide based on copper for aquatic organisms characterized in that the composition of The antifouling layer is substantially free of any biocidal zinc compound and substantially free of dry pitch and in that the biocide based in copper it has a metallic copper content below 2% by weight, based on the total weight of the copper-based biocide.

2. The anti-fouling layer composition according to claim 1, further characterized in that M is Cu, Zn, or Te.

3. - The anti-fouling layer composition according to claim 1 or 2, further characterized in that the film-forming polymer (A) is an acrylic polymer wherein X represents - c- M is copper and R represents fl O-C-R1 wherein R1 is a monovalent organic residue.

4. The anti-fouling layer composition according to any of the preceding claims, further characterized in that the copper-based biocide for an aquatic organism comprises cuprous oxide having a metallic copper content below 2% by weight. weight, based on the total weight of the cuprous oxide.

5. - The anti-fouling coating composition in accordance with claim 4, further characterized in that the cuprous oxide has a metallic copper content below 1% by weight, based on the total weight of cuprous oxide.

6. The anti-fouling layer composition according to any of the preceding claims, further characterized because the copper-based biocide for aquatic organisms comprises copper pyrithione.

7.- The anti-fouling layer composition in accordance with claim 6, further characterized in that the biocide based on copper for the aquatic organism comprises an oxide composition of copper having a metallic copper content below 2% by weight with based on the total weight of cuprous oxide and copper pyrithione.

8. The anti-fouling layer composition according to claim 1, further characterized in that the polymer forming film (A) is an acrylic polymer where X represents fl, M is - c - copper, and R is the residue of an organic monobasic carboxylic acid that has a boiling point greater than 115 ° C, and an acid value between 50 and 950 mgKOH / gram, wherein the copper-based biocide for aquatic organisms comprises a cuprous oxide composition having a metallic copper content below 2% by weight, based on the total weight of cuprous oxide and of pyrithione coppermade.

9. - A procedure to protect a structure made by the man submerged in an encrusting aquatic environment where the The structure is coated with an anti-fouling coating composition according to any of the preceding claims.

10. The method according to claim 9, further characterized because the aquatic environment is a water environment of low salinity. 1.

A man-made structure submerged in an encrusting aquatic environment coated with a layer composition according to any of claims 1 to 8.

12. The man-made structure according to claim 11, characterized also because it is submerged in an aquatic environment of low salinity.

13. The man-made structure according to claim 11, characterized in that it is submerged in an aquatic environment of low salinity during part of its life and in a saline aquatic environment during part of its life.