CONTROLLED RELEASE ANTIFOULING COATING COMPOSITION VIA BIOCIDE INTERACTION

FIELD OF THE INVENTION

The present invention relates to antifouling coating compositions having included therein metal-containing biocides and certain poly(oxyalkylene)-modified alcohols, as well as to coating systems comprising a coat having included such metal-containing biocides and alcohols.

BACKGROUND

Biocides and in particular metal-containing biocides like cuprous oxide and pyrithiones can be used in erodible antifouling coating compositions, in particular those being based on an erodible non-silicone based binder system . One significant challenge in designing such coating compositions is the fact that erodible antifouling coats build up a leach layer which allows for free diffusion of the biocide. Due to the free diffusion through the leach layer, a significant amount of the biocide may be liberated too fast from the coating, whereby a higher amount of the biocide is needed in order to maintain a sufficient level of antifouling activity over time.

JP 2006-052284 discloses the manufacture of an aqueous dispersion of a resin containing a triorganosilyl group. The aqueous dispersion may comprise a silicone oil and optionally a biocide. The silicone oil may among others be a polyether-modified silicone oil .

WO 2011/076856 discloses a fouling control coating composition comprising a polysiloxane- based binder system, one or more hydrophilic-modified polysiloxanes, and one or more biocides. It is disclosed that hydrophilic-modified polysiloxane serves to facilitate the dissolution and transport of biocide to the surface of a coating .

SUMMARY

The present inventors have now found that by re-designing erodible antifouling coating compositions by including therein poly(oxyalkylene)-modified alcohols of the nature specified herein, it is possible to retard the otherwise free diffusion of biocide along the leach layer.

This provides a more efficient use of metal-containing biocides leading to improved antifouling performance by using the same level of biocide, and/or reduction of the amount of biocide needed for obtaining the same antifouling performance, as this controlled release will increase bioavailability of biocide against fouling species for a prolonged period of time.

Without being bound to any particular theory, it is currently believed that the function of the poly(oxyalkylene)-modified alcohols is to create an interaction with the metal-containing biocide which improves the antifouling performance and/or durability of the antifouling effect. The ways to control the leach rate include the molecule size of the poly(oxyalkylene)- modified alcohols, the overall hydrophilicity and the miscibility with the binder.

So, in a first aspect the present invention relates to a solvent-borne antifouling coating composition, cf. claim 1. A second aspect of the invention relates to an antifouling coat, cf. claim 17.

A third aspect of the invention relates to an antifouling coating system, cf. claim 18.

A fourth aspect of the invention relates to a marine structure, cf. claim 20.

A fifth aspect of the invention relates to the use of the combination of one or more poly(oxyalkylene)-modified alcohols and one or more metal-containing biocides for improving the antifouling properties of a coating composition comprising an erodible non-silicone based binder system, cf. claim 21.

DETAILED DESCRIPTION

The solvent-borne antifouling coating composition

The present invention i. a. provides a solvent-borne antifouling coating composition comprising a. an erodible non-silicone based binder system, b. one or more metal-containing biocides, and c. one or more poly(oxyalkylene)-modified alcohols _, wherein the one or more poly(oxyalkylene)-modified alcohols are present in a total amount of 0.05-15% by dry weight based on the coating composition.

Coating compositions (occasionally referred to as "paints" or "paint compositions") typically consists of a binder phase (which forms the paint film upon drying and thereby corresponds to the continuous phase of the final paint coat) and a pigments phase (corresponding to the discontinuous phase of the final paint coat) . According to this simplified understanding, the one or more metal-containing biocides as well as the non-reactive poly(oxyalkylene)-modified alcohols are not part of the continuous phase (the binder phase), but instead forms part of the "pigment phase".

In the present context, the term "solvent-borne" is understood as coating compositions in which the components of the binder system is dissolved in a non-aqueous solvent, and wherein a coat corresponding to the coating composition is formed upon evaporation of the solvent and, in some instance, further upon curing of the binder components.

In a currently preferred embodiment, the solvent-borne coating composition comprises a physically drying binder system which differs from a chemically hardening binder system (see below) in that the binder components (i .e. individual molecules) of the binder system in the dry coat are already present in the same form in the wet coating composition. There is no change in the binder composition or the molecular structure or size of the binder

components. The coat is formed entirely by evaporation of solvents, leaving the binder molecules as chains coiled up and intertwined in the coat.

In another embodiment, the solvent-borne coating composition comprises a chemically hardening binder system characterised in that the final binder molecules in the dry/cured paint film are not present in the wet film. In this instance, the relatively smaller binder component molecules (e.g . monomer) take part in a chemical reaction to form larger molecules, e.g . by chain extension, and possibly involving crosslinking binder components.

In the present context, the term "non-silicone based binder system" is understood in the sense that the binder system of the antifouling coating composition is essentially free of silicone and polysiloxane parts. In particular, any organosilicon parts of the coating composition preferably constitute less than 5 % by dry weight of the binder system, such as less that 2 % by dry weight, or less than 1 % by dry weight, in particular around 0 % by dry weight. Also preferably, any such organosilicon-containing constituents (like silicone and polysiloxane) are not part of the backbone of the binder(s), but may represent groups/chains pendant to the binder component backbone. The binder system

The binder systems applicable in the present invention are erodible non-silicone based binder systems.

In most practical embodiments, the non-silicone based binder system constitutes 25-80 % by solids volume of the coating composition. In preferred embodiments, the non-silicone based binder system constitutes 20-70 % by solids volume, such as 18-55 % by solids volume of the coating composition.

When expressed by dry weight, typically the non-silicone based binder system constitutes 18-75 % by dry weight of the coating composition. In preferred embodiments, the non silicone based binder system constitutes 16-60 %, such as 15-40 %, by dry weight of the coating composition.

The binder systems described herein are of the erodible type ("self-polishing").

When used herein, the term "erodible" (occasionally referred to as "self-polishing") is intended to mean that the paint coat (i.e. the dried film of the coating composition) should have a polishing rate of at least 1 pm per 10,000 Nautical miles (18,520 km). In preferred embodiments, the polishing rate is in the range of 1-50 pm, in particular in the range of 1-30 pm, per 10,000 Nautical miles (18,520 km).

The binder phase of the coating composition forms the paint film upon drying and thereby corresponds to the continuous phase of the final (dry) paint coat.

It is envisaged that all erodible binder systems conventionally used in "self-polishing" coating compositions may be used as the binder system of the present coating composition. It is also found that with respect to the relative amounts of binder system vs. pigments/fillers/etc., only minor modifications (optimizations) may be necessary in order to obtain suitable polishing rates with respect to the marine environment to which the paint coat will be exposed.

For the purpose of illustrating the scope of the present invention with respect to possible types of binder systems, a number of examples of binder systems for marine purposes and yacht purposes, are provided in the following.

It is believed that, the following types of constituents within the binder system are especially interesting : non-aqueous dispersion binder systems, silylated acrylate binder systems, metal acrylate binder system, hybrids of silylated acrylate and metal acrylate binder systems, polyoxalate binder systems, zwitterion binder systems, hybrids of silylated acrylate, , polyester binder system, (natural) rosin, rosin derivatives, disproportionated rosin, partly polymerised rosin, hydrogenated rosin, gum rosin, disproportionated gum rosin, acrylic resins, polyvinyl methyl ether, and vinyl acetate-vinylchloride-ethylene terpolymers.

Among these, it is believed that rosin binder systems, non-aqueous dispersion binder systems, silylated acrylate binder systems, metal acrylate binder system, hybrids of silylated acrylate and metal acrylate binder systems, polyoxalate binder systems, zwitterion binder systems, hybrids of silylated acrylate, and polyester binder systems, are especially interesting.

Particularly preferred binder systems are non-silicone based binder system comprising constituents selected from rosin based binder systems, silyl acrylate binder systems, non- aqueous dispersion based binder systems, and metal-acrylate based binder systems.

Some of these binder systems will - for illustrative purposes - be describe in further detail in the following.

Non-aaueous dispersion binder system

The terms "non-aqueous dispersion resin", "NAD" and similar expressions are intended to mean a shell-core structure that includes a resin obtained by stably dispersing a high- polarity, high-molecular weight resin particulate component (the "core component") into a non-aqueous liquid medium in a low-polarity solvent using a high-molecular weight component (the "shell component").

The non-aqueous dispersion resin may be prepared by a method wherein a polymerisable ethylenically unsaturated monomer which is soluble in a hydrocarbon solvent and which is polymerisable to form a polymer (the core component) which is insoluble in the hydrocarbon solvent, is subjected to dispersion polymerisation in accordance with a conventional method in the hydrocarbon solvent in the presence of a shell component (the dispersion stabiliser) made of a polymer which dissolves or swells in the solvent.

The non-aqueous dispersion-type resin utilised in this invention can be a resin known per se; or it can be produced like the known resins. Such non-aqueous dispersion-type resins and method for their preparation are described in, e.g., US 3,607,821, US 4,147,688, US 4,493,914 and US 4,960,828, Japanese Patent Publication No. 29,551/1973 and Japanese Laid-open Patent Application No. 177,068/1982. Specifically, as the shell component constituting the non-aqueous dispersion-type resin, various high-molecular substances soluble in a low-polarity solvent which are described in, e.g., US 4,960,828 (Japanese Laid- open Patent Application No. 43374/1989), can be used.

From the aspect of antifouling property of the final paint coat, shell components such as an acrylic resin or a vinyl resin may be used.

As the core component, a copolymer of an ethylenically unsaturated monomer having a high polarity is generally applicable. Preferably the core component of the non-aqueous dispersion-type resin has free acid groups or silyl ester groups that are convertible into the acid group by hydrolysis in sea water or combinations thereof. Preferably 5-75 % by weight, e.g. 5-60 % by weight or 7-50 % by weight, of the monomers of the core polymer should carry free acid groups or silyl ester groups or combinations thereof. As the free acid groups will have direct influence on the properties of the paint formulation, whereas the silyl ester groups will only have influence after hydrolysis in seawater, it is presently preferred to have an overweight of free acid groups.

Examples of silyl ester monomers are silyl esters of acrylic or methacrylic acid.

If desired, a smaller proportion of the free acid groups or silyl ester groups may also be contained in the shell component.

The expression "free acid group" is intended to cover the acid group in the acid form. It should be understood that such acid groups temporarily may exist on salt form if a suitable counter ion is present in the composition or in the environment. As an illustrative example, it is envisaged that some free acid groups may be present in the sodium salt form if such groups are exposed to salt water.

Preferably the non-aqueous dispersion-type resin has a resin acid value of usually 15-400 mg KOH/g, preferably 15 to 300 mg KOH/g, such as 18 to 300 mg KOH/g. If the total acid value of the NAD resin is below 15 mg KOH/g, the polishing rate of the paint coat is too low and the antifouling property will often be unsatisfactory. On the other hand, if the total acid value is above 400 mg KOH/g, the polishing rate is too high for that reason a problem of water resistance (durability of the paint coat in seawater) becomes a problem. (When the core component and/or the shell component contain the acid precursor group, the resin acid value is one given after the group is converted into the acid group by hydrolysis). The "resin acid value" here referred to is an amount (mg) of KOH consumed to neutralise 1 g of a resin (solids content), expressing a content of an acid group (in case of the acid precursor group, a content of an acid group formed by hydrolysis) of the resin (solids content). It is advisable that the acid group and/or the acid precursor group is contained in the core component such that the content thereof is, as a resin acid value, at least 80 %, preferably at least 90 %, more preferably at least 95 % of the total resin acid value of the non-aqueous dispersion-type resin.

This being said, it is normally preferred that the shell component is hydrophobic. The dry weight ratio of the core component to the shell component in the NAD resin is not especially limited, but is normally in the range of 90/10 to 10/90, preferably 80/20 to 25/75, such as 60/40 to 25/75.

Silylated acrylate binder system

In another interesting embodiment of the invention the binder system to be used in the coating composition according to the invention comprises a silylated acrylate co-polymer having at least one side chain bearing at least one terminal group of the general formula (I) :

wherein n is an integer of 0, 1, 2, etc., and X is -C(=0)-, and R _x , R ₂ , R3, R ₄ and R ₅ are as defined below.

While n is an integer of 0, 1, 2, 3, 4 or more, it is in these cases preferred that n is 0-100, e.g. 0-50, such as 0 or 1 or 2 or 2-15.

R1-R5 are each groups being the same or different and being selected from Ci. ₂ o-alkyl (e.g. methyl, ethyl, propyl, butyl, cycloalkyl such as cyclohexyl) ; optionally substituted aryl (e.g . substituted phenyl and substituted naphthyl) . Examples of substituents for aryl are halogen, Ci-5-alkyl, Ci-10-alkylcarbonyl, sulphonyl, nitro, or amino. Typically R ₁ -R ₅ are each selected from Ci-s-alkyl and optionally substituted phenyl . It is generally preferred that each of the alkyl groups has up to about 5 carbon atoms (Ci. ₅ -alkyl) . As indicated above, R1-R5 may be the same or different groups.

Monomers comprising the terminal groups of the general formula I above may be synthesised as described in EP 0 297 505 Bl . Such monomers may be co-polymerised with a vinyl polymerisable monomer (A) in order to obtain a co-polymer. Examples of suitable vinyl polymerisable monomers (A) include methacrylate esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2- ethylhexyl methacrylate, 2-hydroxyethyl methacrylate and methoxy ethyl methacrylate; acrylate esters such as ethyl acrylate, butyl acrylate, 2 ethylhexyl acrylate and 2- hydroxyethyl acrylate; maleic acid esters such as dimethyl maleate and diethyl maleate; fumaric acid esters such as dimethyl fumarate and diethyl fumarate; styrene, vinyltoluene, a- methylstyrene, vinyl chloride, vinyl acetate, butadiene, acrylamide, acrylonitrile, methacrylic acid, acrylic acid, isobornyl methacrylate and maleic acid.

The amount of vinyl polymerisable monomers is not more than 95 % by weight of the total weight of the resulting co-polymer, preferably not more than 90 % by weight. Accordingly, the amount of monomers comprising the terminal groups of the general formula I above is at least 5 % by weight, in particular at least 10 % by weight.

The co-polymers preferably have weight average molecular weights in the range of 1,000- 1,500,000, such as in the range of 5,000-1,500,000, e.g. in the range of 5,000-1,000,000, in the range of 5,000-500,000, in the range of 5,000-250,000, or in the range of 5,000- 100,000.

In another interesting embodiment of the invention the binder system to be used in the coating composition according to the invention comprises a silylated acrylate copolymer having at least one side chain bearing at least one terminal group of the general formula II (i.e. formula I wherein n = 0) :

R ₃

— X— O— Si— F¾ (II)

Rs

wherein X, R ₃ , R ₄ and R ₅ are as defined above.

Examples of monomers having a terminal group of the general formula II (shown above) are acid functional vinyl polymerisable monomers, such as monomers derived from acrylic acid, methacylic acid, maleic acid (preferably in the form of a monoalkyl ester with 1-6 carbon atoms) or fumaric acid (preferably in the form of a monoalkyl ester with 1-6 carbon atoms).

Thus, specific examples of a suitable triorganosilyl group (i.e. the -Si(R ₃ )(R ₄ )(R ₅ ) group) shown in the general formula I or II include trimethylsilyl, triethylsilyl, tri-n-propylsilyl, tri-n- butylsilyl, tri-/so-propylsilyl, tri-n-pentylsilyl, tri-n-hexylsilyl, tri-n-octylsilyl, tri-n-dodecylsilyl, triphenylsilyl, tri-p-methylphenylsilyl, tribenzylsilyl, tri-2-methylisopropylsilyl, tri-tert-butyl- silyl, ethyldimethylsilyl, n-butyldimethylsilyl, di-/so-propyl-n-butylsilyl, n-octyl-di-n-butylsilyl, di-/so-propyloctadecylsilyl, dicyclohexylphenylsilyl, tert-butyldiphenylsilyl, dodecyldiphenyl- silyl and diphenylmethylsilyl.

Specific examples of suitable methacrylic acid-derived monomers bearing at least one terminal group of the general formula I or II include trimethylsilyl (meth)acrylate, triethyl- silyl(meth)acrylate, tri-n-propylsilyl(meth)acrylate, triisopropylsilyl (meth)acrylate, tri-n- butylsilyl (meth)acrylate, triisobutylsilyl (meth)acrylate, tri-tert-butylsilyl(meth)acrylate, tri- n-amylsilyl (meth)acrylate, tri-n-hexylsilyl (meth)acrylate, tri-n-octylsilyl (meth)acrylate, tri- n-dodecylsilyl (meth)acrylate, triphenylsilyl (meth)acrylate, tri-p-methylphenylsilyl (meth)- acrylate, tribenzylsilyl (meth)acrylate, ethyldimethylsilyl (meth)acrylate, n-butyldimethylsilyl (meth)acrylate, diisopropyl-n-butylsilyl (meth)acrylate, n-octyldi-n-butylsilyl (meth)acrylate, diisopropylstearylsilyl (meth)acrylate, dicyclohexylphenylsilyl (meth)acrylate, t-butyldiphenyl- silyl (meth)acrylate, and lauryldiphenylsilyl (meth)acrylate.

Specific examples of suitable maleic acid-derived and fumaric acid-derived monomers bearing at least one terminal group of the general formula I or II include triisopropylsilyl methyl maleate, triisopropylsilyl amyl maleate, tri-n-butylsilyl n-butyl maleate, tert-butyldiphenylsilyl methyl maleate, t-butyldiphenylsilyl n-butyl maleate, triisopropylsilyl methyl fumarate, triisopropylsilyl amyl fumarate, tri-n-butylsilyl n-butyl fumarate, tert-butyldiphenylsilyl methyl fumarate, and tert-butyldiphenylsilyl n-butyl fumarate.

In an interesting embodiment of the present invention, the co-polymer to be used in the binder system comprises monomer units with a terminal group of the general formulae I and II (as discussed above) in combination with a second monomer B of the general formula III :

Y-(CH(R _A )-CH(R _B )-0) _p -Z (III) wherein Z is a Ci- ₂ o-alkyl group or an aryl group; Y is an acryloyloxy group, a methacryloyl- oxy group, a maleinoyloxy group or a fumaroyloxy group; R _A and R _B are independently selected from the group consisting of hydrogen, Ci. ₂ o-alkyl and aryl; and p is an integer of 1 to 25. If p> 2, R _A and R _B are preferably hydrogen or CH ₃ , i .e. if p> 2 the monomer B is preferably derived from a polyethylene glycol or a polypropylene glycol . If p= l it is contemplated that monomers, wherein R _A and R _B are larger groups, such as Ci- ₂₀ -alkyl or aryl, may also be useful for the purposes described herein. As shown in formula III, monomer B has in its molecule an acryloyloxy group, a methacryloyloxy group, a maleinoyloxy group (preferably in the form of a mono-Ci- ₆ -alkyl ester), or a fumaroyloxy group (preferably in the form of a mono-Ci- ₆ -alkyl ester) as an unsaturated group (Y) and also alkoxy- or

aryloxypolyethylene glycol. In the alkoxy- or aryloxypolyethylene glycol group, the degree of polymerisation (p) of the polyethylene glycol is from 1 to 25.

Specific examples of monomer B which has a (meth)acryloyloxy group in a molecule include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, propoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, hexoxyethyl (meth)acrylate, methoxydiethylene glycol

(meth)acrylate, methoxytriethylene glycol (meth)acrylate, ethoxydiethylene glycol

(meth)acrylate, and ethoxytriethylene glycol (meth)acrylate.

Specific examples of monomer B which has a maleinoyloxy or fumaroyloxy group in a molecule include methoxyethyl n-butyl maleate, ethoxydiethylene glycol methyl maleate, ethoxytriethylene glycol methyl maleate, propoxydiethylene glycol methyl maleate, butoxy ethyl methyl maleate, hexoxyethyl methyl maleate, methoxyethyl n-butyl fumarate, ethoxydiethylene glycol methyl fumarate, ethoxytriethylene glycol methyl fumarate, propoxydiethylene glycol methyl fumarate, butoxyethyl methyl fumarate, and hexoxyethyl methyl fumarate.

As will be understood by the person skilled in the art, other vinyl monomers may be incorporated in the resulting co-polymer comprising either monomer units having a terminal group of the general formulae I or II (shown above) or in the resulting co-polymer comprising monomer units having a terminal group of the general formulae I or II (shown above) in combination with the second monomer B of the formula III (shown above).

With respect to other monomers co-polymerisable with the above-mentioned monomers, use may be made of various vinyl monomers such as the vinyl polymerisable monomers (A) discussed above.

It is preferred that the proportion of the monomer having a terminal group of the general formulae I or II is from 1-95 % by weight, that of monomer B is from 1-95 % by weight, and that of other monomer(s) co-polymerisable therewith is from 0-95 % by weight on the basis of the total weight of the monomers.

The molecular weight of the resulting co-polymer thus obtained is desirably in the range of 1,000-150,000, such as in the range of 3,000-100,000, e.g. in the range of 5,000-100,000 in terms of weight-average molecular weight. In a further interesting embodiment of the present invention, the binder system to be used in the coating composition according to the invention comprises a co-polymer having monomer units with a terminal group of the general formulae I or II (as discussed above) in

combination with a second monomer C of the general formula IV:

wherein Y is an acryloyloxy group, a methacryloyloxy group, a maleinoyloxy group or a fumaroyloxy group, and both of R ₆ and R ₇ are Ci ^-alkyl.

As shown in formula IV, monomer C has in its molecule an acryloyloxy group, a

methacryloyloxy group, a maleinoyloxy group (preferably in the form of a mono-Ci- ₆ -alkyl ester), or a fumaroyloxy group (preferably in the form of a mono-Ci_ ₆ -alkyl ester) as an unsaturated group (Y) and also a hemi-acetal group.

Monomer C can be prepared by an ordinary addition reaction of a carboxy group-containing vinyl monomer selected from acrylic acid, methacrylic acid, maleic acid (or monoester thereof), and fumaric acid (or monoester thereof), with an alkyl vinyl ether (e.g. ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, and 2-ethylhexyl vinyl ether), or a cycloalkyl vinyl ether (e.g. cyclohexyl vinyl ether).

As will be understood by the person skilled in the art, other vinyl monomers may be incorporated in the resulting co-polymer comprising monomer units having a terminal group of the general formulae I or II (shown above) in combination with the second monomer C of the formula IV (shown above).

With respect to other monomers co-polymerisable with the above-mentioned monomers, use may be made of various vinyl monomers such as the vinyl polymerisable monomers (A) discussed above.

It is preferred that the proportion of the monomer having a terminal group of the general formulae I or II is from 1-95 % by weight (preferably from 1-80 % by weight), that of monomer C is from 1-95 % by weight (preferably from 1-80 % by weight), and that of other monomer(s) co-polymerisable therewith is up to 98 % by weight on the basis of the total weight of the monomers.

The molecular weight of the co-polymer is desirably in the range of 1,000-150,000, preferably in the range of 3,000-100,000, such as in the range of 5,000-100,000 in terms of weight-average molecular weight.

Metal acrylate binder system

In an interesting embodiment of the invention the binder system to be used in the coating composition according to the invention comprises a metal acrylate co-polymer having at least one side chain bearing at least one terminal group of the general formula V:

-X-0-M-(L) _n (V) wherein X is -C(=0)-, -S(=0) ₂ -, -P(=0)(OH)-; M is a metal having a valency of 2 or more; n is an integer of 1 or more with the proviso that n+ 1 equals the metal valency; L is an organic acid residue and each L is independently selected from the group consisting of

o

— S— R ₄ and — o— S— R ₄

O

wherein R ₄ is a monovalent organic residue, or L is -OH or combinations thereof; R ₃ is hydrogen or a hydrocarbon group having from 1 to 10 carbon atoms.

Examples of monomers having a terminal group of the general formulae V (shown above) are acid-functional vinyl polymerisable monomers, such as methacrylic acid, acrylic acid, p- styrene sulfonic acid, 2-methyl-2-acrylamide propane sulfonic acid, methacryl acid phosphoxy propyl, methacryl 3-chloro-2-acid phosphoxy propyl, methacryl acid phosphoxy ethyl, itaconic acid, maleic acid, maleic anhydride, monoalkyl itaconate (e.g. methyl, ethyl, butyl, 2-ethyl hexyl), monalkyl maleate (e.g. methyl, ethyl, butyl, 2-ethyl hexyl; half-ester of acid anhydride with hydroxyl containing polymerisable unsaturated monomer (e.g. half-ester of succinic anhydride, maleic anhydride or phthalic anhydride with 2-hydroxy ethyl methacrylate. The above-mentioned monomers may be co-polymerised (in order to obtain the co-polymer with one or more vinyl polymerisable monomers. Examples of such vinyl polymerisable monomers are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, 2-ethyl hexyl acrylate, 2-ethyl hexyl methacrylate, methoxy ethyl methacrylate, styrene, vinyl toluene, vinyl pyridine, vinyl pyrolidone, vinyl acetate, acrylonitrile, methacrylonitrile, dimethyl itaconate, dibutyl itaconate, di-2-ethyl hexyl itaconate, dimethyl maleate, di (2-ethyl hexyl) maleate, ethylene, propylene and vinyl chloride.

With respect to the ligand (L), each individual ligand is preferably selected from the group consisting of

wherein R ₄ is a monovalent organic residue. Preferably, R ₄ is selected from the group consisting of

wherein R ₅ is hydrogen or a hydrocarbon group having from 1 to 20 carbon atoms; R ₆ and R ₇ each independently represents a hydrocarbon group having from 1 to 12 carbon atoms; R ₈ is a hydrocarbon group having from 1 to 4 carbon atoms; and R ₉ is cyclic hydrocarbon group having from 5 to 20 carbon atoms, such as abietic acid, pallustric acid, neoabietic acid, levopimaric acid, dehydroabietic acid, pimaric acid, isopimaric acid, sandaracopimaric acid and A8,9-isopimaric acid.

Examples of compounds which may be used as ligands are:

(1) Compounds comprising the group O

o—c e.g. aliphatic acids, such as levulinic acid; alicyclic acids, such as naphthenic acid, chaulmoogric acid, hydnocarpusic acid, neo abietic acid, levo pimaric acid, palustric acid, 2- methyl-bicyclo-2,2,l-heptane-2-carboxylic acid; aromatic carboxylic acids such as salicylic acid, cresotic acid, a-naphthoic acid, b-naphthoic acid, p-oxy benzoic acid; halogen containing aliphatic acids, such as monochloro acetic acid, monofluoro acetic acid; halogen containing aromatic acids, such as 2,4,5-trichloro phenoxy acetic acid, 2,4- dichloro phenoxy acetic acid, 3,5-dichloro benzoic acid; nitrogen-containing organic acids, such as quinoline carboxylic acid, nitro benzoic acid, dinitro benzoic acid, nitronaphthalene carboxylic acid; lactone carboxylic acids, such as pulvinic acid, vulpinic acid; uracil derivatives, such as uracil- 4-carboxylic acid, 5-fluoro uracil-4-carboxylic acid, uracil-5- carboxylic acid; penicillin-derived carboxylic acids, such as penicillin V, ampicillin, penicillin BT, penicillanic acid, penicillin G, penicillin O; Rifamycin B, Lucensomycin, Salcomycin, chloroamphenicol, variotin, Trypacidine; and various synthetic fatty acids. (2) Compounds comprising the group e.g. dimethyl dithiocarbamate and other dithiocarbamates. (3) Compounds comprising the group

e.g. sulphur containing aromatic compounds, such as l-naphthol-4- sulphonic acid, p-phenyl benzene sulphonic acid, b-naphthalene sulphonic acid and quinoline sulphonic acid.

(4) Compounds comprising the group— S— , such as compounds comprising the following groups

(5) Compounds comprising the group

such as various thiocarboxylic compounds.

(6) Compounds comprising the group -O- or -OH, e.g. phenol, cresol, xylenol, thymol, carvacol, eugenol, isoeugenol, phenyl phenol, benzyl phenol, guajacol, butyl stilbene, (di) nitro phenol, nitro cresol, methyl salicylate, benzyl salicylate, mono-, di-, tri-, tetra- and penta-chlorophenol, chlorocresol, chloroxylenol, chlorothymol, p-chloro-o-cyclo-hexyl phenol, p-chloro-o-cyclopentyl phenol, p-chloro-o-n- hexyl phenol, p-chloro-o-benzyl phenol, p- chloro-o-benzyl-m-cresol and other phenols; b- naphthol, 8-hydroxy quinoline.

With respect to the metal (M), any metal having a valency of 2 or more may be used.

Specific examples of suitable metals include Ca, Mg, Zn, Cu, Ba, Te, Pb, Fe, Co, Ni, Bi, Si, Ti, Mn, Al and Sn. Preferred examples are Co, Ni, Cu, Zn, Mn, and Te, in particular Cu and Zn. When synthesising the metal-containing co-polymer, the metal may be employed in the form of its oxide, hydroxide or chloride. The co-polymer to be used in the binder system in the coating composition according to the invention may be prepared as described in e.g. EP 0 471 204 Bl, EP 0 342 276 Bl or EP 0 204 456 Bl. Monomers comprising the terminal groups of the general formula V above may be co-polymerised (in order to obtain the co-polymer) with other polymerisable unsaturated monomers, any customarily used ethylenically unsatured monomer may be used. Examples of such monomers are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, 2-ethyl hexyl acrylate, 2- ethyl hexyl methacrylate, methoxy ethyl methacrylate, styrene, vinyl toluene, vinyl pyridine, vinyl pyrolidone, vinyl acetate, acrylonitrile, methacrylo nitrile, dimethyl itaconate, dibutyl itaconate, di-2-ethyl hexyl itaconate, dimethyl maleate, di (2-ethyl hexyl) maleate, ethylene, propylene and vinyl chloride. One particular type of co-monomers is acrylic or methacrylic esters wherein the alcohol residue includes a bulky hydrocarbon radical or a soft segment, for example a branched alkyl ester having 4 or more carbon atoms or a cycloalkyl ester having 6 or more atoms, a polyalkylene glycol monoacrylate or monomethacrylate optionally having a terminal alkyl ether group or an adduct of 2-hydroxyethyl acrylate or methacrylate with caprolactone, e.g. as described in EP 0 779 304 Al. If desired, hydroxy-containing monomers, such as 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate, 2-hydroxy propyl acrylate, 2-hydroxy propyl methacrylate may also be used.

It should be noted that in the resulting co-polymer, not all the organic acid side groups need to contain a metal ester bond; some of the organic acid side groups may be left un-reacted in the form of free acid, if desired.

The weight average molecular weight of the metal-containing co-polymer is generally in the range of from 1,000 to 150,000, such as in the range of from 3,000 to 100,000, preferably in the range of from 5,000 to 60,000.

In another interesting embodiment of the invention the coating composition further comprises an amount of an organic ligand at least equal to the ligand-to-metal co-ordination ratio of 1 : 1, said organic ligand being selected from the group consisting of aromatic nitro compounds, nitriles, urea compounds, alcohols, phenols, aldehydes, ketones, carboxylic acids and organic sulphur compounds, whereby the co-polymer defined above forms a polymer complex with the organic ligand in situ.

Examples of monobasic organic acids usable for forming the hybrid salt include

monocarboxylic acids such as acetic, propionic, butyric, lauric, stearic, linolic, oleic, naphthenic, chloroacetic fluoroacetic, abietic, phenoxyacetic, valeric, dichlorophenoxyacetic, benzoic or napthoic acid; and monosulphonic acids such as benzenesulphonic acid, p- toluenesulphonic acid, dodecylbenzenesulphonic acid, naphthalenesulphonic or p- phenylbenzenesulforic acid.

A preferred method for producing the polymeric hybrid salt has been disclosed in Japanese Patent Kokai No. 16809/1989.

Silyl-metal acrylate hybrid

An intriguing further example of an interesting binder is that being based on silyl acrylate monomers (as those described further above) as well as metal acrylate monomers (as those described further above). Such binders will have backbone fragments of the following general formula: and are described e.g. in KR 20140117986.

Polvoxalate binders

A further example of an interesting binder is that based on polyoxalates, e.g. as disclosed in WO 2015/114091.

Zwitterionic binders and hybrids with silyl acrylates

A still further example of an interesting binder is that based on polymer binders having zwitterion monomers possibly combined with silyl acrylate monomers, e.g. as disclosed in WO 2004/018533 and WO 2016/066567. Polyester binders

An even further example of an interesting binder is that based on polyesters, e.g. as disclosed in WO 2014/010702.

Rosin-based binder system

A further interesting binder system may be that based on rosin and/or rosin derivatives, possibly in combination with any of the before-mentioned binder systems.

Examples of constituents of such a rosin-based binder system are rosin, rosin derivatives such as metal salts of rosin i.e. resinates.

The terms "rosin", "resinate" and the like is intended to refer to gum rosin; wood rosin of grades B, C, D, E, F, FF, G, H, I, J, K, L, M, N, W-G, W-W (as defined by the ASTM 0509 standard); virgin rosin; hard rosin; yellow dip rosin; NF wood rosin; tall oil rosin; or colophony or colophonium. The terms "rosin" and "resinate" and the like are also intended to include suitable types of modified rosin, in particular oligomerisation; hydrogenation;

dehydrogenation hydrogenation/disproportionation/dismutation; etc., that will reduce the amount of conjugated non-aromatic double bonds. It should be understood that the group of further binder components may include polymeric flexibilisers such as those generally and specifically defined in WO 97/44401 that is hereby incorporated by reference.

When expressed by dry weight, typically the rosin-based binder system constitutes 5-30 % by dry weight of the coating composition. In preferred embodiments, the non-silicone based binder system constitutes 8-25 %, such as 10-25 %, by dry weight of the coating

composition.

In most practical embodiments, the rosin based binder system constitutes 10-50 % by solids volume of the coating composition. In preferred embodiments, the non-silicone based binder system constitutes 12-45 % by solids volume, such as 15-40 % by solids volume of the coating composition.

Further binder components

The above-mentioned binder systems (e.g. the non-aqueous dispersion binder system, the silylated acrylate binder system and the various hybrids) may have included therein - as a part of the binder system - one or more further binder components. It should be understood that the binder components mentioned below may alone also constitute the binder system, cf. the general presentation of the binder system.

Examples of such further binder components are: oils such as linseed oil and derivatives thereof, castor oil and derivatives thereof, soy bean oil and derivatives thereof; and other polymeric binder components such as saturated polyester resins; polyvinylacetate, polyvinylbutyrate, polyvinylchloride- acetate, copolymers of vinyl acetate and vinyl isobutyl ether; vinylchloride; copolymers of vinyl chloride and vinyl isobutyl ether; alkyd resins or modified alkyd resins; hydrocarbon resins such as petroleum fraction condensates;

chlorinated polyolefines such as chlorinated rubber, chlorinated polyethylene, chlorinated polypropylene; styrene copolymers such as styrene/butadiene copolymers,

styrene/methacrylate and styrene/acrylate copolymers; acrylic resins such as homopolymers and copolymers of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and isobutyl methacrylate; hydroxy-acrylate copolymers; polyamide resins such as polyamide based on dimerised fatty acids, such as dimerised tall oil fatty acids; cyclised rubbers; epoxy esters; epoxy urethanes; polyurethanes; epoxy polymers; hydroxy-polyether resins; polyamine resins; etc., as well as copolymers thereof. Such further binder components typically constitutes 0-25 %, such as 5-20 %, by wet weight.

Metal- biocides

Another prominent constituent of the coating compositions of the present invention is the one or more metal-containing biocides.

In the present context, the term "biocide" is intended to mean an active substance intended to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means.

Illustrative examples of metal-containing biocides are those selected from metal-containing organic biocides like metallo-dithiocarbamates (such as bis(dimethyldithiocarbamato)zinc, zinc-ethylenebis(dithiocarbamate) (Zineb), ethylene-bis(dithiocarbamato)manganese, dimethyl dithiocarbamate zinc, and complexes between these); bis(l-hydroxy-2(lH)- pyridinethionato-0,S)-copper (copper pyrithione); copper acrylate; bis(l-hydroxy-2(lH)- pyridinethionato-0,S)-zinc (zinc pyrithione); phenyl(bispyridyl)-bismuth dichloride; and metal-containing inorganic biocides like metal biocides such as copper(I)oxide, cuprous oxide, and metallic copper, copper metal alloys such as copper-nickel alloys like copper bronze; metal salts such as cuprous thiocyanate, basic copper carbonate, copper hydroxide, barium metaborate, copper chloride, silver chloride, silver nitrate and copper sulphide; and bis(N-cyclohexyl-diazenium dioxy) copper.

Currently preferred examples hereof are copper-containing biocides and zinc-containing biocides, in particular cuprous oxide, copper pyrithione, zinc pyrithione and zinc-ethylenebis- (dithiocarbamate) (Zineb).

Generally, the metal-containing biocide is typically included in an amount of 3-65 %, such as 5-60 %, e.g. 10-60 %, or 15-60 %, or 15-40 %, or 20-60 %, by dry weight of the coating composition. Expressed as solids volume, the amount of the metal-containing biocide is typically 3-45 %, such as 5-40 %, e.g. 7-38 %, or 10-35 %, or 15-35 %, by solids volume of the coating composition.

In one particularly interesting embodiment, the metal-containing biocide includes metal- containing inorganic biocide(s), in particular cuprous oxide. In this embodiment, the biocide (in particular cuprous oxide) is typically included in an amount of 3-65 %, such as 5-60 %, e.g. 10-60 %, or 15-60 %, or 15-40 %, or 20-60 %, by dry weight of the coating composition. Expressed as solids volume, the amount of the inorganic metal-containing biocide (in particular cuprous oxide) is typically 3-45 %, such as 5-40 %, e.g. 7-38 %, or 10- 35 %, or 15-35 %, by solids volume of the coating composition.

In another particularly interesting embodiment, the metal-containing biocide only includes metal-containing organic biocides. In this embodiment, the metal-containing organic biocide(s) is/are typically included in a total amount of 0.25-30 %, such as 0.5-25 %, e.g. 0.75-20 %, or 1-15 %, or even 2-12 %, by dry weight of the coating composition. Expressed as solids volume, the amount of the metal-containing organic biocide is typically 0.5-15 %, such as 1-12 %, e.g. 2-10 %, or 4-9 %, by solids volume of the coating composition.

In still another particularly interesting embodiment, the metal-containing biocide is copper pyrithione and/or zinc pyrithione. In this embodiment, copper pyrithione and zinc pyrithione is typically included in a total amount of 0.25-30 %, such as 0.5-25 %, e.g. 0.75-20 %, or 1- 15%, or even 2-12 %, by dry weight of the coating composition. Expressed as solids volume, the total amount of copper pyrithione and zinc pyrithione is typically 0.5-15 %, such as 1-12 %, e.g. 2-10 %, or 4-9 %, by solids volume of the coating composition.

Within this embodiment, the weight ratio between cuprous oxide and the combined amount of copper pyrithione and/or zinc pyrithione is preferably in the range of 100: 1 to 1 : 2, such as 50: 1 to 1 : 1.5, or 30: 1 to 1 : 1, e.g. 25: 1 to 1 : 1, or 20: 1 to 2: 1.

Within this embodiment, the solids volume ratio between cuprous oxide and the combined amount of copper pyrithione and/or zinc pyrithione is preferably in the range of 30: 1 to 1 : 3, such as 25: 1 to 1 : 2, or 20: 1 to 1 : 1.5, e.g. 15: 1 to 1 : 1.4, or 10: 1 to 1 : 1.2.

In yet another particularly interesting embodiment, the metal-containing biocide is zinc- ethylenebis(dithiocarbamate) (Zineb). In this embodiment, zinc-ethylenebis(dithiocarbamate) (Zineb) is typically included in an amount of 1-30 %, such as 2-20 %, e.g. 3-15 %, or 4- 10%, or even 5-15 %, by dry weight of the coating composition. Expressed as solids volume, the total amount of zinc-ethylenebis(dithiocarbamate) (Zineb) is typically 1-30 %, such as 2- 20 %, e.g. 3-15 %, or 4-10 %, or 5-15 %, by solids volume of the coating composition.

In some embodiments, wherein the metal-containing biocide is cuprous oxide in combination with one or more other metal-containing biocides, the combined amount of biocides is typically an amount of 3-65 %, such as 5-60 %, e.g. 10-60 %, or 15-60 %, or even 20-60 %, by dry weight of the coating composition. Expressed as solids volume, the amount of the cuprous oxide in combination with one or more other metal-containing biocides is typically 3- 45 %, such as 5-40 %, e.g. 7-38 %, or 10-35 %, or 15-35 %, by solids volume of the coating composition.

It should be understood that the metal-containing biocide may be combined with one or more non-metal biocides like heterocyclic nitrogen compounds such as 3a,4,7,7a-tetrahydro-2- ((trichloromethyl)-thio)-lH-isoindole-l,3(2H)-dione, pyridine-triphenylborane, l-(2,4,6- trichlorophenyl)-lH-pyrrole-2,5-dione, 2,3,5,6-tetrachloro-4-(methylsulfonyl)-pyridine, 2- methylthio-4-tert-butylamino-6-cyclopropylamine-s-triazin, and quinoline derivatives;

heterocyclic sulfur compounds such as 2-(4-thiazolyl)benzimidazole, 4,5-dichloro-2-n-octyl- 4-isothiazolin-3-one, 4,5-dichloro-2-octyl-3(2H)-isothiazoline (Sea-Nine ^® -211N), 1,2-benz- isothiazolin-3-one, 2-(thiocyanatomethylthio)-benzothiazole, (RS)- 4-[l-(2,3- dimethylphenyl)ethyl]-3H-imidazole (Medetomidine, Selektope ^® ), and 4-Brom-2-(4- chlorphenyl)-5-(trifluormethyl)-lH-pyrrol-3-carbonitril (Tralopyril, Econea ^® ); urea derivatives such as N-(l,3-bis(hydroxymethyl)-2,5-dioxo-4-imidazolidinyl)-N,N'-b is(hydroxymethyl)urea, and N-(3,4-dichlorophenyl)-N,N-dimethylurea, N,N-dimethylchlorophenylurea; amides or imides of carboxylic acids; sulfonic acids and of sulfenic acids such as 2,4,6-trichlorophenyl maleimide, l,l-dichloro-N-((dimethylamino)sulfonyl)-l-fluoro-N-(4-methy lphenyl)-methane- sulfenamide, 2,2-dibromo-3-nitrilo-propionamide, N-(fluorodichloromethylthio)-phthalimide, N,N-dimethyl-N'-phenyl-N'-(fluorodichloromethylthio)-sulfami de, and N-methylol formamide; salts or esters of carboxylic acids such as 2-((3-iodo-2-propynyl)oxy)-ethanol

phenylcarbamate and N,N-didecyl-N-methyl-poly(oxyethyl)ammonium propionate; amines such as dehydroabiethylamines and cocodimethylamine; substituted methane such as di (2- hydroxy-ethoxy)methane, 5,5'-dichloro-2,2'-dihydroxydiphenylmethane, and methylene- bisthiocyanate; substituted benzene such as 2,4,5,6-tetrachloro-l,3-benzenedicarbonitrile, l,l-dichloro-N-((dimethylamino)-sulfonyl)-l-fluoro-N-phenylm ethanesulfenamide, and 1- ((diiodomethyl)sulfonyl)-4-methyl-benzene; tetraalkyl phosphonium halogenides such as tri- n-butyltetradecyl phosphonium chloride; guanidine derivatives such as n-dodecylguanidine hydrochloride; disulfides such as bis-(dimethylthiocarbamoyl)-disulfide, tetramethylthiuram disulfide; imidazole containing compound, such as medetomidine; 2-(p-chlorophenyl)-3- cyano-4-bromo-5-trifluoromethyl pyrrole and mixtures thereof.

PolvfoxyalkyleneVmodified alcohols

It has been found that functionalization of the hydroxy group of alcohols with

poly(oxyalkylenes) provides compounds which are highly useful in antifouling coatings in combination with biocides, in particular metal-containing biocides such as zinc pyrithione, copper pyrithione, cuprous oxide and Zineb. This will be elaborated on further below and in the Examples section. The coat comprises one or more poly(oxyalkylene)-modified alcohols having the general formula (I) :

(P0A-0-) _x -R-(-0-FA) _Y (I) wherein

each POA represents a poly(oxyalkylene) moiety,

each FA represents a C ₈ -3o fatty acyl moiety,

R represents the organic residue of an alcohol R(OH) _x+Y , said organic residue having 2-50 carbon atoms, and

X is 1-5, Y is 0-10 and X+Y is 1-12.

In the above formula (I), -O- in connection with POA-O- represents an ether oxygen covalently linking the poly(oxyalkylene) and the organic residue of the alcohol. The fatty acyl moiety, FA, is a long chain acyl moiety forming an ester bond (-0-C(=0)-) where the -O- in connection with FA-O- represents an ester oxygen covalently linking a long chain fatty acid and the organic residue of the alcohol.

The organic residue is typically purely of hydrocarbon origin, i.e. consisting of linear, branched, cyclic, unsaturated and/or aromatic moieties, except that it may include 1-5 ether bonds (-C-0-C-) either being part of a ring structure or being attached directly to a ring structure. In some embodiments, the organic residue is of purely hydrocarbon origin.

In one embodiment, the organic residue, R, of the alcohol R(OH) _x+Y has 2-50 carbon atoms, such as 3-50 carbon atoms, and has only linear, branched and/or unsaturated moieties.

In another embodiment, the organic residue, R, of the alcohol R(OH) _x+Y has 2-50 carbon atoms, such as 3-50 carbon atoms, and is selected from substituted phenols, sorbitans, lanolin or sterols. Preferably the organic residue R is selected from lanolin or sterols.

The organic residue, R, such as in the before-mentioned embodiments, typically has 2-50 carbon atoms, e.g. 3-50 carbon atoms, or 6-50 carbon atoms, such as 8-45 carbon atoms, e.g. 9-40 carbon atoms, or 10-35 carbon atoms.

In the embodiments where X+Y is 1, the organic residue typically has 6-50 carbon atom. Typically, the poly(oxyalkylene) moieties, POA, each represents an F^O-fF^-OJ _n -R ³ - moiety wherein R ¹ is selected from hydrogen, Ci- ₄ -alkyl-C(=0)- and Ci- ₄ -alkyl; each R ² and R ³ is selected from ethyl-1, 2-ene and propyl-1, 2-ene; and n is an integer of 1-150.

The poly(oxyalkylene) moiety POA is typically a poly(oxyalkylene) moiety selected from polyoxyethylene, polyoxypropylene and poly(oxyethylene-co-oxypropylene) .

In some interesting embodiments, n is ranging from 4-150, such as from 5-100, such as from 6-75, in particular 6-30.

In one embodiment, the poly(oxyalkylene) is selected from polyoxyethylene and

poly(oxyethylene-co-oxypropylene), preferably from poly(oxyalkylenes), such as those having a number average molecular weight of 100-20,000 g/mol, such as 200-20,000 g/mol, in particular 300-5,000 g/mol.

In one variant hereof, the poly(oxyalkylene) is selected from polyoxyethylenes. Illustrative examples hereof are PEG-30 and PEG-75.

In another variant hereof, the poly(oxyalkylene) is selected from poly(oxyethylene-co- oxypropylene). Illustrative examples hereof are PEG-5/PPG-5 and PEG-10/PPG-3.5.

The fatty acids giving rise to the fatty acyl moieties, FA, upon partial esterification of the alcohol R(OH)x _+Y are C _8-30 fatty acids, such as Ci _0-24 fatty acids. In some variants, the fatty acids may include one or more unsaturated bonds. Examples of fatty acids are stearic acid, lauric acid and oleic acid.

In formula (I), (P0A-0-) _x -R-(-0-FA) _Y , X is 1-5, Y is 0-10 and X+Y is 1-12. Suitably, Y is 1- 10. In some embodiments, X is 1-5 and Y is 0. In other embodiments, X is 1 and Y is 1-10.

In still other embodiments, X is 1-3 and Y is 1-5.

In one embodiment, the coat comprises 1-15 %, such as 2-8 %, in particular 3-7 %, by dry weight of said one or more poly(oxyalkylene)-modified alcohols.

In another embodiment, the coat comprises 1-10 %, such as 2-8 %, in particular 3-7 %, by solids volume of said one or more poly(oxyalkylene)-modified alcohols. In still another embodiment, the coat (or a corresponding coating system) comprising 1-20, such as 2-18, in particular 3-16, g/m ² of said one or more poly(oxyalkylene)-modified alcohols.

In one particular embodiment, the coat comprises one or more poly(oxyalkylene)-modified alcohols which include, or consist of, one or more polvfoxyalkylenej-modified sterols.

Sterols are terpene-derived compounds sharing the generic structure (II)

wherein the 3-position (in the A-ring) is hydroxy functional, and wherein (like in cholesterol) the 17-position typically carries a branched aliphatic chain (the chain C ²⁰ to C ²⁷ is provided as the most typical constitution). Other positions, like the 4-position, the 14-position, etc. may also carry substituents (typically methyl groups), just as the structure may contain ethylenically unsaturated double bonds, e.g. between carbons 5 and 6 like in cholesterol, or between carbon 8 and 9 like in lanosterol. Also, the sterol may have one or more hydroxy groups other than the hydroxy group in the 3-position. In some embodiments, the sterol represents the alcohol R-OH.

The hydroxy group in the 3-position is available for functionalization, e.g. ether-modification such as by means of poly(oxyalkylenes) to provide poly(oxyalkylene)-modified sterols.

Poly(oxyalkylene)-modified sterols may be produced by reacting sterol alcohol with alkylene oxide, thereby polymerising polyalkylene oxide by ring opening polymerisation initiated by the alcohol. Typical sources of such sterols are Aqualose by Croda, Generol by BASF and

Lipolan by Lipo chemicals. It has been found that functionalization of the 3-hydroxy group of sterols with poly(oxyalkylenes) provides compounds which are particularly useful in fouling- release coatings in combination with biocides, in particular organic biocides such as zinc pyrithione, copper pyrithione and Zineb. In the present context, "poly(oxyalkylene)-modified sterols" should be understood as products predominantly consisting of sterols of the generic structure (II) being ether- functionalized at the 3-position with a poly(oxyalkylene) (i.e. -OH in the 3-position being replaced with POA-O-). In the present context, the term "predominantly consisting of" means that at least 75 % by solids weight of the "poly(oxyalkylene)-modified sterols" consist of sterols of the generic structure (II) being ether-functionalized at the 3-position with a poly(oxyalkylene).

Preferably, at least 80 %, such as at least 85, or at least 90 %, by solids weight of the "poly(oxyalkylene)-modified sterols" consist of such sterols. The less than 100 % content of the ether functionalised sterol of the generic structure (II) is due to the fact that many commercially available qualities of "sterols" comprises small amount of impurities.

In another particular embodiment, the alcohol R(OH) _x+Y is selected from phenols.

Phenols are compounds of the generic structure (III) :

wherein the 1-position is hydroxy functional, and where the hydrogen at the 2, 3, 4, 5, or 6- position may be substituted with a linear, branched, cyclic, unsaturated and/or aromatic moiety, which further may carry fatty acyl moieties of the formula -O-FA as specified further above. In one interesting variant, the phenyl is substituted, in particular the 2-, 4- and 6- positions are each substituted, for example with a styryl, a nonyl and/or a butyl group. Hence, in these latter cases, the alcohol may be selected from tristyrylphenol, nonylphenol and tributylphenol.

The hydroxy group in the 1-position is available for functionalization as specified further above by means of poly(oxyalkylenes) to provide poly(oxyalkylene)-modified phenols.

In still another particular embodiment, the alcohol R(OH) _x+Y is a sorbitan. Sorbitan is a compound of the generic structure (IV) : and corresponds to an alcohol of the general formula R(OH) ₄ . Sorbitan may be modified by partial esterification of up to three of the four -OH group by fatty acids leaving one or more - OH groups unmodified and available for poly(oxyalkylene) modification. In some

embodiments of the formula (I), (P0A-0-) _x -R-(-0-FA) _Y , X is 1-3, Y is 1-3 and X+Y is 4, such as where X is 1-2, Y is 2-3, and X+Y is 4.

In a specific embodiment, the poly(oxyalkylene)-modified sorbitan is based on sorbitan trioleate, leaving only one -OH group available for functionalization as specified further above by means of poly(oxyalkylenes) to provide poly(oxyalkylene)-modified sorbitan trioleate, i.e. X is 1 and Y is 3.

In still another particular embodiment, the alcohol is selected from C _6.30 saturated straight or branched chain alcohols, such as saturated straight chain primary alcohols and saturated branched chain secondary or tertiary alcohols. The hydroxy group is available for

functionalization, e.g. ether-modification such as by means of poly(oxyalkylenes) to provide poly(oxyalkylene)-modified C ₆ - o alcohols, e.g. straight chain primary alcohols and poly(oxyalkylene)-modified branched chain secondary and/or tertiary alcohols. In some embodiment, such alcohols have 8-30 carbon atoms, such as 10-24 carbon atoms.

Specific examples of the above-mentioned alcohols are C ₈ - o alkylalcohols, such as Ci ₀ -i ₅ saturated straight chain primary alcohols, branched C _i3 alcohols, and oleyl alcohol. It should be understood that the above embodiments may be viewed independently or in combination. Hence, the one or more poly(oxyalkylene)-modified alcohols may be represented by different of the types specified above or by several variants within the same type.

Solvents, additives, pigments and fillers The coating compositions may further comprise solvents and additives.

The coating compositions described herein are solvent-borne, hence comprises a solvent or a mixture of solvents. The solvents are of non-aqueous. Examples of solvents are aliphatic, cycloaliphatic and aromatic hydrocarbons such as white spirit, cyclohexane, methyl isobutyl ketone (MIBK), toluene, xylene and naphtha solvent, esters such as methoxypropyl acetate, n-butyl acetate and 2-ethoxyethyl acetate; octamethyltrisiloxane, and mixtures thereof.

In one embodiment, the solvents are selected from aliphatic, cycloaliphatic and aromatic hydrocarbons such as white spirit, cyclohexane, toluene, xylene and naphtha solvent, esters such as methoxypropyl acetate, n-butyl acetate and 2-ethoxyethyl acetate;

octamethyltrisiloxane, and mixtures thereof, preferably those solvents having a boiling point of 110 °C or more.

The solvent(s) typically constitute(s) 2-50 % by volume of the coating composition, such as

3-40 %, or 4-30 %, or 5-25 % by volume of the coating composition.

Examples of additives are:

(i) non-reactive fluids such as organopolysiloxanes; for example polydimethylsiloxane, methylphenyl polysiloxane; petroleum oils and combinations thereof;

(ii) surfactants such as derivatives of propylene oxide or ethylene oxide such as alkylphenol- ethylene oxide condensates (alkylphenol ethoxylates); ethoxylated monoethanolamides of unsaturated fatty acids such as ethoxylated monoethanolamides of linoleic acid; sodium dodecyl sulfate; and soy a lecithin;

(iii) wetting agents and dispersants such as those described in M. Ash and I. Ash, "Handbook of Paint and Coating Raw Materials, Vol. 1", 1996, Gower Publ. Ltd., Great Britain, pp 821- 823 and 849-851;

(iv) thickeners and anti-settling agents (e.g. thixotropic agents) such as colloidal silica, hydrated aluminium silicate (bentonite), aluminium tristearate, aluminium monostearate, xanthan gum, chrysotile, pyrogenic silica, hydrogenated castor oil, organo-modified clays, polyamide waxes and polyethylene waxes;

(v) dyes such as l,4-bis(butylamino)anthraquinone and other anthraquinone derivatives; toluidine dyes, etc. ; and

(vi) antioxidants such as bis(tert-butyl) hydroquinone, 2,6-bis(tert-butyl) phenol, resorcinol,

4-tert-butyl catechol, tris(2,4-di-tert-butylphenyl)phosphite, pentaerythritol tetrakis(3-(3,5- di-tert-butyl-4-hydroxyphenyl)propionate), bis(2,2,6,6,-tetramethyl-4-piperidyl)sebacate, etc.

Any additives typically constitute 0-30 %, such as 0-15 %, by dry weight of the coating composition. Preferably, the coating composition comprises one or more thickeners and/or anti-settling agents (e.g. thixotropic agents), preferably in an amount of 0.2-10 %, such as 0.5-5 %, e.g. 0.6-4 %, by dry weight of the coating composition.

Furthermore, the coating composition used for forming the coat may comprise pigments and fillers.

Pigments and fillers are in the present context viewed in conjunction as constituents that may be added to the coating composition with only limited implications on the adhesion properties. "Pigments" are normally characterised in that they render the final paint coating non-transparent and non-translucent, whereas "fillers" normally are characterised in that they do not render the paint non-translucent and therefore do not contribute significantly to hide any material below the coating.

Examples of pigments are grades of titanium dioxide, red iron oxide, zinc oxide, carbon black, graphite, yellow iron oxide, red molybdate, yellow molybdate, zinc sulfide, antimony oxide, sodium aluminium sulfosilicates, quinacridones, phthalocyanine blue, phthalocyanine green, black iron oxide, indanthrone blue, cobalt aluminium oxide, carbazole dioxazine, chromium oxide, isoindoline orange, bis-acetoacet-o-tolidiole, benzimidazolon, quinaphtalone yellow, isoindoline yellow, tetrachloroisoindolinone, quinophthalone yellow.

Examples of fillers are calcium carbonate such as calcite, dolomite, talc, mica, feldspar, barium sulfate, kaolin, nephelin, silica, perlite, magnesium oxide, and quartz flour, etc. Fillers (and pigments) may also be added in the form of nanotubes or fibres, thus, apart from the before-mentioned examples of fillers, the coating composition may also comprise fibres, e.g. those generally and specifically described in WO 00/77102 which is hereby incorporated by reference.

Any pigments and/or fillers typically constitute 0-60 %, such as 0-50 %, preferably 5-45 %, such as 5-40 %, or 5-35 %, or 0.5-25 %, or 1-20 %, by dry weight of the coating composition. Taking into account the density of any pigments and/or fillers, such constituents typically constitute 0.2-20 %, such as 0.5-15 % by solids volume of the coating composition

With the aim of facilitating easy application of the coating composition (e.g. by spray, brush or roller application techniques), the coating composition typically has a viscosity in the range of 25-25,000 mPa-s, such as in the range of 150-15,000 mPa-s, in particular in the range of 200-4,000 mPa-s. Specific embodiments

In one interesting embodiment, the invention provides a solvent-borne antifouling coating composition comprising 18-40 % by dry weight of an erodible non-silicone based binder system, 20-55 % by dry weight of one or more metal-containing biocides and 0.05-15 % by dry weight of one or more poly(oxyalkylene)-modified alcohols.

In another interesting embodiment, the invention provides a solvent-borne antifouling coating composition comprising 18-40 % by dry weight of an erodible non-silicone based binder system, 0.25-30 % by dry weight of one or more metal-containing organic biocides and 0.05-15 % by dry weight of one or more poly(oxyalkylene)-modified alcohols.

In a further interesting embodiment, the invention provides a solvent-borne antifouling coating composition, wherein said coating composition comprises 1-15 % by dry weight of said one or more poly(oxyalkylene)-modified alcohols and 2-20 % by dry weight of said one or more biocides.

Preferred binder systems to be used in combination with the above embodiments are, rosin based binder systems, silyl acrylate binder systems, non-aqueous dispersion based binder systems, and metal-acrylate based binder systems.

Antifouling coat

A further aspect of the present invention is an antifouling coat (occasionally referred to as a "paint coat" or a "coating") comprising an erodible non-silicone based binder matrix, one or more metal-containing biocides, and one or more poly(oxyalkylene)-modified alcohols. The constituents are as defined further above for the paint composition, and any descriptions, preferences and variants also apply for the coat which simply represents the coating composition when allowed to dry.

Preferably, the antifouling coat is such that it comprises 1-40, such as 2-30, in particular 3- 20 g/m ² of said one or more poly(oxyalkylene)-modified alcohols and 10-500, such as 15- 350, such as 20-250, such as 30-200, in particular 50-150 g/m ² of said one or more metal- containing biocides. Preparation of coating composition

The antifouling coating composition is used to prepare a corresponding antifouling coat.

The coating compositions may be prepared by any suitable technique that is commonly used within the field of paint production. Thus, the various constituents may be mixed together utilizing a mixer, a high speed disperser, a ball mill, a pearl mill, a grinder, a three-roll mill etc. The coating compositions are typically prepared and shipped as one or two- component systems that should be combined and thoroughly mixed immediately prior to use. The paints according to the invention may be filtrated using bag filters, patron filters, wire gap filters, wedge wire filters, metal edge filters, EGLM turnoclean filters (ex. Cuno), DELTA strain filters (ex. Cuno), and Jenag Strainer filters (ex. Jenag), or by vibration filtration. An example of a suitable preparation method is described in the Examples.

First alternative aspect of the invention - A coating system

The present invention also relates to an antifouling coating system comprising at least a first coat and a second coat, a) said first coat comprising an erodible non-silicone based binder system, said first coat further comprising one or more poly(oxyalkylene)-modified alcohols; and b) said second coat comprising an erodible non-silicone based binder system, said second coat further comprising one or more metal-containing biocides.

In this alternative to the main aspect of the invention, the antifouling coat is such that it comprises 1-40, such as 2-30, in particular 3-20 g/m ² of said one or more

poly(oxyalkylene)-modified alcohols and 10-500, such as 15-350, such as 20-250, such as 30-200, in particular 50-150 g/m ² of said one or more metal-containing biocides.

It should be understood that the first coat as well as the second coat are prepared on a substrate in such a way that the second coat is prepared on top of the first coat. Also, it should be understood that the first coat may be prepared on an already existing coating layer, e.g . an anti-corrosive coating layer, or an aged antifouling or fouling-release coat, etc., or directly on a native substrate (see further below in the section "Application of coating compositions". Moreover, although the second coat is preferably the outermost layer, the second coat may in principle be over-coated with a further coating layer (e.g. a top-coat) . Without being bound to any particular theory, it is believed that outermost coat (i.e. the second coat) contains the metal-containing biocide, and the first coat (the underlying layer) contains polyoxyalkylene-modified alcohol, which then migrates to the outermost layer and provides a similar effect as that described for the main aspect of the invention.

Hence, the antifouling coating system comprises at least a first coat and a second coat. First, the first coat as well as in the second coat (except that the binder system is not necessarily identical) is described in the above sections, "The binder system", " Polyoxyalkylene-modified alcohol" (where applicable), "Solvents, additives, pigments and fillers", "Metal-containing Biocides" (where applicable), etc.. Subsequently, the specific features of the first coat is described in the section "The first coat .." below, whereas the specific features of the second coat is further described in the section "The second coat .." further below.

It should be understood that although the first coat and the second coat typically are of the same or similar type (or even identical) with respect to the binder system, the first coat and the second coat are not identical. In particular, the first coat and the second coat at least differs with respect to at least one of i) the content and/or type of metal-containing biocide(s), and ii) the content and/or type of the polyoxyalkylene-modified alcohol(s).

Further embodiments of how the first coat and the second coat are prepared are outlined in the sections "Application of the coating system" and "A marine structure" further below.

The first coat of the coating system

The coating composition used for establishing the first coat of the coating system is essentially as described above for the antifouling coating in the section "The solvent-borne antifouling coating composition", except that the first coat does not have - as a mandatory constituent - included a metal-containing biocide. Otherwise, the first coat is a described above, mutatis mutandis.

In one embodiment, the first coat comprises:

18-40 % by dry weight of an erodible non-silicone based binder system,

0.2-5 % by dry weight of one or more polyoxyalkylene-modified alcohols, one or more additives, and

one or more pigments and fillers. In one variant of the above, the first coat further comprises one or more metal-containing biocides or other biocides, in particular of the types and in the amounts specified further above in the section "Metal-containing biocides".

The second coat of the coating system

The coating composition used for establishing the second coat of the coating system is essentially as described above for the antifouling coating in the section "The solvent-borne antifouling coating composition", except that the first coat does not have - as a mandatory constituent - included a polyoxyalkylene-modified alcohol. Otherwise, the first coat is a described above, mutatis mutandis.

In one embodiment the second coat comprises:

18-40 % by dry weight of an erodible non-silicone based binder system,

20-55 % by dry weight of one or more metal-containing biocides,

one or more additives, and

one or more pigments and fillers.

In one variant of the above, the second coat further comprises one or more

poly(oxyalkylene)-modified alcohols, in particular of the types and in the amounts specified further above in the section "Polyoxyalkylene-modified alcohols ".

Application of the coating composition

The coating composition of the invention is typically applied to at least a part of the surface of a substrate.

The term "applying" is used in its normal meaning within the paint industry. Thus, "applying" is conducted by means of any conventional means, e.g. by brush, by roller, by spraying, by dipping, etc. The commercially most interesting way of "applying" the coating composition is by spraying. Hence, the coating composition is preferably sprayable. Spraying is effected by means of conventional spraying equipment known to the person skilled in the art. The coating is typically applied in a dry film thickness of 50-600 pm, such as 50-500 pm, e.g. 75- 400 pm, or 20-150 pm, or 30-100 pm. Moreover, the coating composition is preferably such with respect to sag resistance cf. ASTM D 4400-99 (i.e. relating to its ability to be applied in a suitable film thickness to a vertical surface without sagging) that it exhibits sag resistance for a wet film thickness up to at least 70 pm, such as up to at least 200 pm, e.g. up to at least 300 pm, preferably up to at least 400 pm, and in particular up to at least 600 pm.

The term "at least a part of the surface of a substrate" refers to the fact that the coating composition may be applied to any fraction of the surface. For many applications, the coating composition is at least applied to the part of the substrate (e.g. a vessel) where the surface (e.g. the ship's hull) may come in contact with water, e.g. sea-water.

The term "substrate" is intended to mean a solid material onto which the coating composition is applied. The substrate typically comprises a metal such as steel, iron, aluminium, or glass- fibre reinforced polyester. Suitably, the substrate is a metal substrate, in particular a steel substrate. Alternatively, the substrate is a glass-fibre reinforced polyester substrate. In some cases, the substrate is at least a part of the outermost surface of a marine structure.

The term "surface" is used in its normal sense, and refers to the exterior boundary of an object. Particular examples of such surfaces are the surface of marine structures, such as vessels (including but not limited to boats, yachts, motorboats, motor launches, ocean liners, tugboats, tankers, container ships and other cargo ships, submarines, and naval vessels of all types), pipes, shore and off-shore machinery, constructions and objects of all types such as piers, pilings, bridge substructures, floatation devices, water-power installations and structures, underwater oil well structures, nets and other aquatic culture installations, cooling plants, and buoys, etc., and is especially applicable to the hulls of ships and boats and to pipes.

The surface of the substrate may either be the "native" surface (e.g. the steel surface).

However, the substrate is typically coated, e.g. with an anticorrosive coating and/or a tie coat, so that the surface of the substrate is constituted by such a coating. When present, the (anticorrosive and/or tie) coating is typically applied in a total dry film thickness of 100-600 pm, such as 150-450 pm, e.g. 200-400 pm. Alternatively, the substrate may carry a paint coat, e.g. a worn-out antifouling paint coat, or similar.

Preferably, the substrate is a metal substrate (e.g. a steel substrate) coated with an anticorrosive coating such as an anticorrosive epoxy-based coating, e.g. cured epoxy-based coating, or a shop-primer, e.g. a zinc-rich shop-primer. The substrate may also be a glass- fiber reinforced polyester substrate coated with an epoxy primer coating. The coat of the main aspect of the invention is typically applied as the outermost coat (a. k.a. a top-coat), i.e. the coat being exposed to the environment, e.g. an aquatic environment. However, it should be understood that the coat of the main aspect of the invention alternatively may be applied as a layered system where the coat described in the main aspect of this invention will be coated with one or more layer(s) of one or more other coating compositions in order to obtain an improve control of the leaching rate of the leachable components in the coat.

Prior to the application of a coating composition to a marine structure, the marine structure may first be coated with a primer-system which may comprise several layers and may be any of the conventional primer systems used in connection with application of coating

compositions to marine structures. Thus, the primer system may include an anti-corrosive primer optionally followed by a layer of an adhesion-promoting primer.

This being said, the invention also relates to a method of establishing an antifouling coating system on a surface of a substrate, comprising the sequential steps of: a) applying one or more layers of a primer composition onto the surface of said substrate, thereby forming a primed substrate, b) applying one or more layers of the solvent-borne antifouling coating composition of the invention onto the surface of said primed surface, and allowing said layer(s) to dry/cure, thereby forming a antifouling coat as defined hereinabove (main aspect) .

In some variants of the above-mentioned method, the antifouling coat may be further coated with a top-coat.

This being said, the invention also relates to a method of establishing an antifouling coating system on a surface of a substrate (according to the first alternative aspect), comprising the sequential steps of: a) applying one or more layers of a solvent-borne antifouling coating composition onto the surface of said substrate, e.g. either a native substrate or a substrate already carrying one or more coatings, as the case may be, and allowing said layer(s) to dry/cure, thereby forming a first coat as defined hereinabove for the first alternative aspect, and b) applying one or more layers of a solvent-borne antifouling coating composition of the invention onto the surface of said first coat, and allowing said layer(s) to dry/cure, thereby forming a second coat as defined hereinabove for the first alternative aspect. The invention also relates to a method of establishing an antifouling coating system on a surface of a substrate (according to the first alternative aspect), comprising the sequential steps of: a) applying one or more layers of a primer composition onto the surface of said substrate, and allowing said layer(s) to dry/cure, thereby forming a primed substrate, b) applying one or more layers of a solvent-borne antifouling coating composition of the invention onto the surface of said primed substrate, and allowing said layer(s) to dry/cure, thereby forming a first coat as defined hereinabove for the first alternative aspect, and c) applying one or more layers of a solvent-borne antifouling coating composition of the invention onto the surface of said first coat, and allowing said layer(s) to dry/cure, thereby forming a second coat as defined hereinabove for the first alternative aspect.

The invention further relates to a method of establishing an antifouling coating system on a surface of an aged antifouling coating system, comprising the sequential steps of: a) applying one or more layers of a sealer/link-coat composition onto the surface of said substrate, allowing said layer(s) to dry/cure, thereby forming a sealed substrate, b) applying one or more layers of a solvent-borne antifouling coating composition of the invention onto the surface of said primed substrate, and allowing said layer(s) to dry/cure, thereby forming a first coat as defined hereinabove for the first alternative aspect, and c) applying one or more layers of a solvent-borne antifouling coating composition of the invention onto the surface of said first coat, and allowing said layer(s) to dry/cure, thereby forming a second coat as defined hereinabove for the first alternative aspect.

The invention further relates to a method of establishing an antifouling coating system on a surface of an aged antifouling coating system, comprising the sequential steps of: a) applying one or more layers of a solvent-borne antifouling coating composition onto the surface of said aged antifouling coating system, and allowing said layer(s) to dry/cure, thereby forming a first coat as defined hereinabove for the first alternative aspect, and b) applying one or more layers of a solvent-borne antifouling coating composition of the invention onto the surface of said first coat, and allowing said layer(s) to dry/cure, thereby forming a second coat as defined hereinabove for the first alternative aspect.

A Marine Structure

The present invention further provides a marine structure comprising on at least a part of the outer surface thereof an outermost antifouling coat as defined hereinabove under the section "Antifouling coat". In particular, at least as part of the outer surface carrying the outermost coating is a submerged part of said structure.

The present invention also provides a marine structure comprising on at least a part of the outer surface thereof an outermost antifouling coating system as defined hereinabove under the section "First alternative aspect of the invention". In particular, at least as part of the outer surface carrying the outermost coating is a submerged part of said structure.

The coating composition, the method of establishing the coating on the substrate surface, and the characteristics of the coating follow the directions given hereinabove.

In one embodiment, the antifouling coating system of the marine structure may consist of an anticorrosive layer and the antifouling coating system as described herein.

In an alternative embodiment, the antifouling coating composition is applied on top of a used antifouling coating system, e.g. on top of a used antifouling coat.

In one particular embodiment of the above marine structure, the anticorrosive layer has a total dry film thickness of 100-600 pm, such as 150-450 pm, e.g . 200-400 pm; and the antifouling coating has a total dry film thickness of 20-500 pm, such as 20-400 pm, e.g. 50- 300 pm .

A further embodiment of the marine structure is that where at least a part of the outermost surface of said structure is coated with an antifouling coating system comprising a total dry film thickness of 150-400 pm of an anticorrosive layer of an epoxy-based coating established by application of 1-4, such as 2-4, layers; and

a total dry film thickness of 20-400 pm of the antifouling coating (according to the main aspect) established by application of 1-2 layers. A further embodiment of the marine structure is that where at least a part of the outermost surface of said structure is coated with an antifouling coating system (first alternative aspect) comprising a total dry film thickness of 150-400 pm of an anticorrosive layer of an epoxy-based coating established by application of 1-4, such as 2-4, layers;

a total dry film thickness of 20-400 pm of the first coat (cf. the first alternative aspect) of the antifouling coating established by application of 1-2 layers; and

a total dry film thickness of 20-400 pm of the second coat (cf. the first alternative aspect) of the antifouling coating established by application of 1-2 layers. Uses

A further aspect of the invention relates to the use of the combination of one or more poly(oxyalkylene)-modified alcohols and one or more metal-containing biocides, for improving the antifouling properties of a coating composition comprising an erodible non silicone based binder system. The nature of the constituents are described in the above sections, "The binder system", "Polyoxyalkylene-modified alcohol", "Solvents, additives, pigments and fillers", "Metal- containing Biocides", etc.

General Remarks

Although the present description and claims occasionally refer to a binder, a biocide, etc., it should be understood that the coating compositions defined herein may comprise one, two or more types of the individual constituents. In such embodiments, the total amount of the respective constituent should correspond to the amount defined above for the individual constituent.

The "(s)" in the expressions: compound(s), agent(s), etc. indicates that one, two or more types of the individual constituents may be present.

On the other hand, when the expression "one" is used, only one (1) of the respective constituent is present. It should be understood that when reference is made to the coating composition, it is the mixed coating composition. Furthermore all amounts stated as % by solids volume of the coating should be understood as % by solids volume of the mixed coating composition (or the final coat) unless stated otherwise. It should be understood that the expression "% dry weight" means the percentage of the respective component based on the dry weight of the coat or of the coating composition, as the case may be. For most practical purposes (hence, unless otherwise stated), the "% dry weight" when referring the final coat is identical to the "% dry weight" of the coating composition. EXAMPLES

Materials

Binders:

Chinese Gum Rosin ex. Arawaka Chemical Industries, (China), Gum Rosin

Hypale CH ex. Arakawa Chemical Industries (China) Foral AX-E, ex Eastman Chemicals (Netherlands), Hydrogenated rosin

Acronal 9020 ex BASF (Germany), 60 wt.% solution in xylene, Acrylate co-binder

Synocryl 7013-SD50 ex Archema (Spain), 50 wt.% solution in butanol/petroleum (1 : 2), Acrylic co-binder

NSP-100 ex Nitto Kasei, (Japan), 50 wt.% solution xylene/ ethylbenzene (1 : 1), Silylated acrylic copolymer binder solution

Plasticizer; 45 wt.% solution in xylene,

Polvoxyalkylene-modified alcohols according to the invention:

Reference alcohols:

Biocides:

Nordox Cuprous Oxide Paint Grade, ex Nordox, (Norway), cuprous oxide

Copper Omadine ex Arch Chemicals, (China), copper pyrithione

Zineb Nautec ex United Phosphorous, (India), zinc-ethylenebis(dithiocarbamate)

Solvents:

Xylene

Additives:

Thickener:

Bentone 38 ex Elementis Specialties, (United Kingdom)

Wetting agents:

Nuosperse 657 RD ex Elementis Specialties (Netherlands)

Disperbyk 164 ex BYK Chemie, (Germany)

Anti-gelling agents:

DTBHQ ex Hangzhou Thomas (China), 2,5-diterbutyl hydroquinone

Thixotropic agents: Aditix M 60 ex Supercolori (Italy), Modified polyethylene wax

Pigments and fillers:

Zinc Oxide Red Seal ex Umicore (Netherlands)

Kronos 2310 ex Kronos Titan A/S, (Germany), titanium dioxide

Iron oxide pigment; Micronox R01 ex Promindsa (Spain)

Casiflux F75 ex Ankerpoort (Netherlands), Natural calcium silicate

Rockforce ^® MS603-Roxul ^® 1000 ex Lapinus Fibres BV (Netherlands), Man-made vitreous fibres

Methods

Antifouling property test

An acrylic test panel (15 x 20 cm ² ), sandblasted on one side to facilitate adhesion of the coating, is first coated with 80 pm (DFT) of a commercial vinyl tar primer (Hempanyl 16280 ex Flempel's Marine Paints A/S) applied by air spraying. After a minimum drying time of 24 hours in the laboratory at room temperature the test paint is applied with a Doctor Blade type applicator, with four gap sizes with a film width of 80 mm. One coat was applied in a DFT of 90-100 pm. After at least 72 hours drying the test panels are fixed on a rack and immersed in sea water.

Test at Vilanova i la Geltrii in Northeastern Spain

In this test site the panels are immersed in seawater with salinity in the range of 37-38 parts per thousand at an average temperature in the range of 17-18 °C. Every 1-12 weeks, inspection of the panels is made and the antifouling performance is evaluated according to the scale shown in Table 2. One score is given for the total fouling of the types: algae and animals.

Test at Singapore

In this test site the panels are immersed in seawater with salinity in the range of 29-31 parts per thousand at a temperature in the range of 29-31°C. Every 1-12 weeks, inspection of the panels is made and the antifouling performance is evaluated according to the scale shown in Table 2. One score is given for the total fouling of the types: algae and animals.

Preparation of coating compositions for text examples

The coating compositions are prepared following the standard procedure. An initial dispersion of the binder(s) in organic solvent, followed by addition of part or all the additives such as thixotropic agents, etc., and eventually the addition of part or all the pigments such as zinc oxide, fibres, etc. are mixed on a Diaf dissolver equipped with an impeller disc. Further, the rest of the pigments such as cuprous oxide, zinc-ethylenebis(dithiocarbamate) (Zineb) is added, and a temperature activation of any component that may require it (e.g. thixotropic agent) is initiated. The coating compositions are finally let down with the remaining additives and binders, and its rheology adjusted with final addition of remaining organic solvent.

Typically, the solid components of the coating composition are mixed and ground. The polyoxyalkylene-modified alcohols may alternatively be added in initial or later additive addition step.

The coating composition may be prepared as a one-component paint or by mixing two or more components e.g. two pre-mixtures, one pre-mixture comprising the one or more resins and one pre-mixture comprising the one or more curing agents.

It should be understood that the expression "% dry weight" means the percentage of the respective component based on the dry weight of the coat or of the coating composition, as the case may be. For most practical purposes (hence, unless otherwise stated), the "% dry weight" when referring the cured coat is identical to the "% dry weight" of the coating composition. TEST EXAMPLES

Model paints

Table 1

This table illustrates the effect of the poly(oxyalkylene)-modified sterols (PEG-15 lanolin) at different concentrations together with different biocides.

The antifouling performance is improving with increasing levels of the poly(oxyalkylene)- modified sterol.

Table 2 This table illustrate the effect of the different types of poly(oxyalkylene)-modified sterols and lanolin oils at 2 wt-%.

All the poly(oxyalkylene)-modified sterols perform better than the blank and better than the pure lanolins. Pure lanolin performs better than the blank.

Table 3 This table illustrates the effect of 2 wt-% of poly (oxylakylene)-modified alcohol in the form of short alkyl ether ethoxylates.

PEG-alkyl with short(C10-13) alkyl chains (Examples 14-16) improve the performance in CuO paints compared to blank and the short chain alkyl only additive (Reference example 17). In CuPt paints the performance is the same.

Table 4

This table illustrates the effect of 2 wt-% of poly (oxylakylene)-modified alcohol in the form of long alkyl ether ethoxylates.

PEG-alkyl with long alkyl chains (Examples 18-21) improve performance with CuPt and CuO paints both in Spain and Singapore compared to the blank and long alkyl chain additive.

Table 5

This table illustrates the effect of 2 wt-% of poly (oxylakylene)-modified alcohol in the form of alkyl ether modified sorbitans.

Poly (oxylakylene)-modified alcohols in the form of alkyl ether modified sorbitan (Examples 23-25) improve performance with CuPt and CuO paints both in Spain and Singapore compared to the blank and a sorbitan without PEG. Table 6

Effect of poly(oxyalkylene)-modified alcohol in the form of poly(oxyalkylene)-modified phenols.

Poly (oxylakylene)-modified phenols (Examples 28-33) improve performance with CuPt in Spain compared to the blank. For Singapore, examples 28-30 and 32 improve the performance, whereas for examples 31 and 33 the performance is at the same level as the blank. For CuO, examples 28-30 improves the performance in Singapore, whereas for examples 31-33 the performance is at the same level as the blank.

Table 7 Effect of an alternative poly(oxyalkylene)-modified alcohol.

The PEG12 is a poly(oxyalkylene)-modified alcohol according to formula I, without a fatty acyl group. It performs better than the blank using both CuPt/zineb and CuO/zineb.