GB2558739A

GB2558739A - Antifouling composition

Info

Publication number: GB2558739A
Application number: GB1718577.8A
Authority: GB
Inventors: Tobias Boman Kjartan; Dahling Marit
Original assignee: Jotun AS
Current assignee: Jotun AS
Priority date: 2016-11-11
Filing date: 2017-11-10
Publication date: 2018-07-18
Anticipated expiration: 2037-11-10
Also published as: CN108070055B; KR20230047343A; GB201718577D0; JP2018109147A; JP7161845B2; GB2558739B; CN108070055A; KR20180053261A; KR102547145B1; DE102017126336A1

Abstract

A silyl ester copolymer comprising as comonomers: [a] triisopropylsilyl methacrylate (TISMA), [b] one or more compounds, tetrahydrofurfuryl acrylate, isopropylideneglycerol acrylate, glycerolformal acrylate or cyclic trimethylolpropane formal acrylate, of formula (I) wherein Ak is a cyclic ether (such as oxolane, oxane, dioxolane, dioxane optionally alkyl substituted and Hy is a C1-C4 alkylene, and optionally [c] one or more comonomers, such as methoxyethyl methacrylate (MEMA), ethyl diethyleneglycol acrylate (EDEGA), of formula (II) wherein R2 is H or CH3, and R3 is a C3-C18 substituent comprising oxygen or nitrogen, and wherein the sum of [a]+[b]+[c] is greater or equal to 50 mol%. Also disclosed is use of the silyl ester copolymer in an antifouling coating composition, such as a marine antifouling agent. The antifouling agent may comprise of a copper compound biocide or be free of a copper compound. A rosin or derivative thereof can be used as a binder for the antifouling coating composition.

Description

(56) Documents Cited:

EP 3078715 A1 EP 2912120 A1 EP 2725073 A1

EP 2935288 A1 EP 2781567 A1 EP 2348077 A1 (71) Applicant(s):

Jotun A/S

PO Box 2021, Sandefjord 3202, Norway (72) Inventor(s):

Kjartan Tobias Boman Marit Dahling (74) Agent and/or Address for Service:

Dehns

St. Bride's House, 10 Salisbury Square, LONDON, EC4Y 8JD, United Kingdom (58) Field of Search:

INT CL C08F, C09D Other: EPODOC, WPI.

(54) Title of the Invention: Antifouling composition

Abstract Title: A silyl ester copolymer and use thereof in an antifouling composition (57) A silyl ester copolymer comprising as comonomers: [a] triisopropylsilyl methacrylate (TISMA), [b] one or more compounds, tetrahydrofurfuryl acrylate, isopropylideneglycerol acrylate, glycerolformal acrylate or cyclic trimethylolpropane formal acrylate, of formula (I)

X,

Χχ

At wherein Ak is a cyclic ether (such as oxolane, oxane, dioxolane, dioxane optionally alkyl substituted and Hy is a C,C₄ alkylene, and optionally [c] one or more comonomers, such as methoxyethyl methacrylate (MEMA), ethyl diethyleneglycol acrylate (EDEGA), of formula (II)

X* wherein R2 is H or CH₃, and R3 is a C₃-Ci₈ substituent comprising oxygen or nitrogen, and wherein the sum of [a] +[b]+[c] is greater or equal to 50 mol%. Also disclosed is use of the silyl ester copolymer in an antifouling coating composition, such as a marine antifouling agent. The antifouling agent may comprise of a copper compound biocide or be free of a copper compound. A rosin or derivative thereof can be used as a binder for the antifouling coating composition.

Antifouling Composition

Field of the Invention

The present invention relates to marine antifouling coating compositions, more specifically to marine antifouling coating compositions comprising a silyl ester copolymer comprising triisopropyl silyl methacrylate (TISMA) and an acrylate of a cyclic ether such as tetrahydrofurfuryl acrylate (THFA) as comonomers. The invention further relates to a method of protecting objects from fouling, and objects coated with the antifouling composition of the invention.

Background of invention

Surfaces that are submerged in seawater are subjected to fouling by marine organisms such as green and brown algae, barnacles, mussels, tube worms and the like. On marine constructions such as vessels, oil platforms, buoys, etc. such fouling is undesired and has economic consequences. The fouling may lead to biological degradation of the surface, increased load and accelerated corrosion. On vessels the fouling will increase the frictional resistance which will cause reduced speed and/or increased fuel consumption. It can also result in reduced manoeuvrability.

To prevent settlement and growth of marine organisms antifouling paints are used. These paints generally comprise a film-forming binder, together with different components such as pigments, fillers, solvents and biologically active substances.

The most successful self-polishing antifouling systems on the market today are based on silyl ester functional (meth)acrylic copolymers. These coating compositions are for example described in, EP 0 646 630, EP 0 802 243, EP 1 342 756, EP I 479 737, WO 2005/005516, WO 00/77102, WO 03/070832 and WO 03/080747.

Silyl ester functional (meth)acrylic copolymers are often used together with other binders such as acrylates and rosin or rosin derivatives to adjust the selfpolishing properties and the mechanical properties of antifouling coating films. A biocide such as copper oxide or an organic biocide such as 4-bromo-2-(4P1612 _ 3phenyl)-5-(trifluoromethyl)-lH-pyrrole-3-carbonitrile [tralopyril] may also be included.

Silyl ester copolymers including THFA as a comonomer are known but the combination of monomers TISMA and THFA has not previously been described.

WO2011/092143 discloses an antifouling coating composition which includes a hydrolysable copolymer and at least one hydrocarbon resin. Although an example is provided which comprises THFA as comonomer, the silyl-ester comonomer is not TISMA and the mole percentage of a+b+c defined, is less than 50 mol%.

EP1479737 discloses an antifouling coating composition which include a hydrolysable copolymer formed between a triarylsilyl(meth)acrylate and (meth)acrylate comonomer(s). The examples demonstrate terpolymers of triphenyl silyl methacrylate (TPSMA), methyl methacrylate (MMA) and a third acrylate or methacrylate comonomer, which may be THFA. The proportion of nonMMA comonomers (mol%) is below 28 mol% in all cases.

JP8269389 discloses marine antifouling coatings based on a copolymer of an unsaturated trialkyl silyl comonomer and a least one comonomer. The nature of the comonomer is quite varied and includes methacrylate and acrylate derivatives. In one example a copolymer of tri(n-butyl)silyl methacrylate (TBSMA) and tetrahydrofurfuryl methacrylate (THFMA) in a 20:80 ratio by weight (13:87 mol) is described, and in another a copolymer of tri(n-butyl)silyl acrylate (TBSA), tetrahydrofurfuryl methacrylate (THFMA) and methyl methacrylate (MMA) in a ratio by weight of 50:10:40 (29:9:62 mol) is described.

EP 0 646 630 describes antifouling coatings which include a hydrolysable copolymer formed between a trialkylsilyl (meth)acrylate comonomer and a polar acrylate comonomer including 1-25 ethylene glycol repeating units. In an example, triisopropyl silyl methacrylate is used in combination with methoxy ethyl methacrylate and another polar acrylate comonomer having 9 repeating glycol units, methyl methacrylate and n-butyl acrylate. There is no mention of THFA.

The present inventors have now surprisingly established that a silyl ester copolymer incorporating, for example, both triisopropyl silyl methacrylate (TISMA) and acrylates of cyclic ethers such as tetrahydrofurfuryl acrylate (THFA) as

P1612 _ nomers provides a self-polishing antifouling coating with improved antifouling performance, in particular in terms of the prevention of fouling on marine surfaces.

Typical service intervals for vessels are from 30 to 90 months. It requires a slow, controlled polishing rate of the coating film to protect the object through the full service interval. Too fast polishing will result in consumption of the antifouling coating before the end of the service interval resulting in an unprotected surface during the last period and thereby fouling of the surface. Too slow polishing will result in insufficient release of biocides to protect the surface and thereby fouling of the surface. A linear, controlled polishing over the life time will give a constant release of biocides and thereby excellent fouling protection.

There is a need for silyl ester copolymers that give a controlled degradation of antifouling coatings.

Summary of invention

In one aspect the invention relates to a silyl ester copolymer comprising as comonomers:

(a) triisopropyl silyl methacrylate (TISMA);

(b) one or more compounds of Formula (I):

O ^R1 (I) wherein R¹ is cyclic ether (such as oxolane, oxane, dioxolane, dioxane optionally alkyl substituted) and W is a C1-C4 alkylene group, preferably tetrahydrofurfuryl acrylate (THFA); and optionally (c) one or more comonomers of Formula (II):

P1612

wherein R² is H or CH₃, and R³ is a C3-C18 substituent comprising at least one oxygen or nitrogen atom, preferably at least one oxygen atom; and wherein the sum of the mole fractions of (a)+(b)+(c) in the copolymer is > 50 mol%.

It is preferred that the silyl ester copolymer has a glass transition temperature (Tg) of at least 25 °C as measured by DSC according to the method of the examples section described herein.

In another aspect the invention provides an antifouling coating composition comprising the silyl ester copolymer of the invention and at least one antifouling agent. The antifouling coating composition may comprise an antifouling agent such as cuprous oxide and/or copper pyrithione or the antifouling coating composition may comprise copper free biocides.

In another aspect the invention provides a process for protecting an object from fouling, said process comprising coating at least a part of said object which is subject to fouling with an antifouling coating composition as defined herein.

The invention also relates to objects coated with the antifouling coating composition as defined herein.

Viewed from another aspect the invention relates to the use of the silyl ester copolymer defined herein in an antifouling coating composition, i.e. as a binder for such a composition.

Definitions

The terms “marine antifouling coating composition”, “antifouling coating composition” or simply “coating composition” refer to a composition which is

P1612 »le for use in marine environments. The antifouling coating composition requires an antifouling agent, e.g. a biocide.

The term “hydrocarbyl group” refers to any group containing C atoms and H atoms only and therefore covers alkyl, alkenyl, aryl, cycloalkyl, arylalkyl groups and so on.

The term “(meth)acrylate” means a methacrylate or acrylate.

The term “rosin” used in the text which follows is being used to cover “rosin or derivatives thereof’.

The term “binder” defines part of the composition which includes the silylester copolymer and any other components which together form a matrix giving substance and strength to the composition. Typically the term “binder” used herein means the silyl ester copolymer along with any rosin which may be included.

Detailed description of invention

In one embodiment, the antifouling coating composition of the invention comprises a silyl ester copolymer which includes at least the comonomers TISMA and an acrylate of a cyclic ether such as tetrahydrofurfuryl acrylate (THFA). Additional silyl ester (meth)acrylate comonomers, hydrophilic (meth)acrylate comonomers, and/or non-hydrophilic (meth)acrylate comonomers may additionally be present as described herein.

Silyl ester copolymer

Comonomers

The silyl ester copolymer includes at least the comonomers (a) TISMA and (b) an acrylate of a cyclic ether such as THFA.

Where a mol% of a given comonomer in the silyl ester copolymer is given, the mol% is relative to the sum total (mol) of each comonomer present in the copolymer. Thus if TISMA and THFA are the only comonomers in the silyl ester copolymer, the mol% of TISMA is calculated as (TISMA (mol) / (TISMA (mol) + THFA (mol))) x 100%. If only TISMA, THFA and methyl methacrylate (MMA) are

P1612 _r .. nt, the mol% of TISMA is calculated as (TISMA (mol) / (TISMA (mol) + THFA (mol) + MM A (mol))) x 100%. Percentages by weight of the copolymer are calculated analogously. The copolymer preferably comprises >90 wt%, preferably >95 wt%, especially >98 wt% of the combination of silyl ester (meth)acrylate, hydrophilic (meth)acrylate and non-hydrophilic (meth)acrylate comonomers.

Component (a) is triisopropylsilyl methacrylate (TISMA), which preferably forms 15 to 70 mol% of the copolymer, preferably 20 to 60 mol%, more preferably 25 to 50 mol%.

Component (b) preferably forms 2 to 50 mol%, preferably 3 to 40 mol%, especially 5 to 35 mol% of the copolymer.

The ratio (a):(b) (mol/mol) is preferably in the range of 30:70 to 95:5, preferably in the range of 40:60 to 90:10, especially in the range of 50:50 to 70:30. It is preferred that the mole fraction of (a) in the copolymer is greater than that of (b).

Acrylate of a cyclic ether component (b)

The second monomer (b) is a cyclic ether esters of acrylic acid given by the formula:

O

wherein R¹ is cyclic ether (such as oxolane, oxane, dioxolane, dioxane optionally alkyl substituted) and W is a C1-C4 alkylene. W is preferably a C1-C2 alkylene.

The cyclic ether may contain a single oxygen atom in the ring or 2 or 3 oxygen atoms in the ring. The cyclic ether may contain a ring comprising 2 to 8 carbon atoms, such as 3 to 5 carbon atoms. The whole ring might comprise 4 to 8 atoms, such as 5 or 6 atoms.

The cyclic ether ring may be substituted such as by one or more, such as one, Cl-6 alkyl group. That substituent group might be at any position on the ring including the position that binds to the W group.

P1612

Suitable compounds of Formula (I) include isopropylideneglycerol acrylate, glycerolformal acrylate, cyclic trimethylolpropane formal acrylate and tetrahydrofurfuryl acrylate (THF A). The use of THF A is especially preferred.

The use of these comonomers with TISMA ensures the formation of a binder that has a controlled degradation.

In a further embodiment, the monomers of Formula (I) above can be combined with TISMA and triisopropylsilyl acrylate (TISA).

Additional hydrophilic (meth)acrylate comonomer(s) (c)

In certain embodiments the copolymer may include one or more additional comonomers of Formula (II):

wherein R² is H or CH₃, and R³ is a C3-C18 substituent with at least one oxygen or nitrogen atom, preferably at least one oxygen atom. As used herein, this structure defines a “hydrophilic” (meth)acrylate comonomer. An additional comonomer of Formula (II) must not fall within the scope of Formula (I). Ideally,

R³ does not comprise a cyclic ether. R³ is preferably a linear or branched C3-C18 substituent containing at least one oxygen or nitrogen atom, preferably at least one oxygen atom.

As indicated in the above formula, the term “hydrophilic (meth)acrylate” requires the R³ group in Formula (II) to include at least one oxygen or nitrogen atom, preferably at least one oxygen atom. As explained in detail below, additional non-hydrophilic (meth)acrylate comonomers may also be present in the silyl ester copolymer, in which the R unit consists of C and H atoms only.

In Formula (II) above, the R³ group is preferably of formula (CH₂CH₂O)n-R⁴where R⁴ is a Cl-CIO hydrocarbyl substituent, preferably a Cl-CIO alkyl or C6-C10

P1612 _J ubstituent and n is an integer in the range of 1 to 6, preferably 1 to 3.

Preferably R³ is of formula (CH₂CH₂O)n-R⁴ where R⁴ is a Cl-ClO-alkyl substituent, preferably methyl or ethyl, and n is an integer in the range of 1 to 3, preferably 1 or

2.

Particularly preferred amounts of component (c), where present, are 2 to 30 mol%, preferably 5 to 20 mol%, such as 5 to 15 mol%. Where a mixture of comonomers of Formula (II) are present, these amounts relate to the combined mole fraction of the comonomers of Formula (II) in the copolymer.

Where a comonomer of Formula (II) is present, particularly preferred comonomer(s) include methoxy ethyl methacrylate (MEMA), methoxy ethyl acrylate (MEA) and ethyl diethyleneglycol acrylate (EDEGA), preferably MEMA or EDEGA.

Additional non-hydrophilic (meth)acrylate comonomer(s)

The silyl ester copolymer may include one or more additional (meth)acrylate comonomers of Formula (III)

wherein R⁵ is H or CH₃, and R⁶ is a C1-C8 hydrocarbyl substituent, preferably a Cl20 C8 alkyl substituent, most preferably methyl, ethyl, n-propyl, 2-ethylhexyl or nbutyl. Comonomers according to Formula (III) are referred to as “non-hydrophilic” comonomers herein.

Preferably the silyl ester copolymer contains at least one additional nonhydrophilic methacrylate and/or non-hydrophilic acrylate comonomer. Where one or more non-hydrophilic (meth)acrylate comonomers are present, the sum of these (meth)acrylate comonomers in the silyl ester copolymer is preferably at most 50 mol%, preferably no more than 45 mol%, such as no more than 40 mol%, such as in the range of 15 to 45 mol%.

P1612

In a preferred embodiment the comonomers TISMA, THFA and any nonhydrophilic (meth)acrylate comonomer according to Formula (III) together form >80 mol%, preferably >85 mol%, especially >90 mol% of the comonomers in the silyl-ester copolymer.

In a preferred embodiment the silyl ester copolymer includes one or more of the comonomers methyl methacrylate (MMA) and/or n-butyl acrylate (n-BA).

In all embodiments of the invention it is preferred that methyl methacrylate (MMA) is included in addition to TISMA and THFA. Where present, MMA is preferably present in an amount of 10 to 50 mol%, preferably 15 to 45 mol% of the copolymer. In a preferred embodiment TISMA, THFA and MMA together form >80 mol%, preferably >85 mol%, especially >90 mol% of the comonomers in the silyl ester copolymer.

In a particularly preferred embodiment the copolymer includes 20 to 70 mol% of TISMA, 2 to 50 mol% of THFA and 10 to 45 mol% of MMA; especially 20 to 40 mol% of TISMA, 5 to 40 mol% of THFA, and 15 to 45 mol% of MMA. In these embodiments additional silyl (meth)acrylate, hydrophilic (meth)acrylate and/or non-hydrophilic (meth)acrylate comonomers may be included.

Where present, n-BA is preferably present in an amount of 5 to 30 mol%, such as 5 to 20 mol%.

In an embodiment the silyl ester copolymer includes the comonomers TISMA, THFA, MMA and at least one hydrophilic or further non-hydrophilic acrylate comonomer. In an embodiment the silyl ester copolymer comprises, consists or consists essentially of the monomers: TISMA, THFA, MMA and n-BA; TISMA, THFA , MMA and EDEGA; or TISMA, THFA , MMA, n-BA and EDEGA. In a further embodiment, the silyl ester copolymer comprises, consists or consists essentially of the monomers: TISMA, THFA and one or more of MMA, nBA; EDEGA, MEMA and MEA.

Additional silyl (meth)acrylate comonomers

P1612

The silyl ester copolymer may include additional silyl (meth)acrylate comonomers. Where present, suitable silyl (meth)acrylate comonomers are preferably of Formula (IV)

FT I

X+Si-O-H ^Jn

R^y ¹ 11 -Si—R¹¹

I

R (IV) wherein

R⁷ and R⁸ are each independently selected from linear or branched C1-C4 alkyl groups;

R⁹, R¹⁰ and R¹¹ are each independently selected from the group consisting of linear or branched C1-C20 alkyl groups, C3-C12 cycloalkyl groups, optionally substituted C6-C20aryl groups and -OSi(R¹²)3 groups;

each R¹² is independently a linear or branched C1-C4 alkyl groups, n is an integer from 0 to 5;

X is an ethylenically unsaturated group, such as acryloyloxy group, methacryloyloxy group, (methacryloyloxy)alkylenecarbonyloxy group and (acryloyloxy)alkylenecarbonyloxy group. It will be appreciated that triisopropyl silyl methacrylate should be regarded as excluded from Formula (IV) as it is always present in the silyl ester copolymer of the invention.

The term alkyl is intended to cover both linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl and butyl. Particularly preferred cycloalkyl groups include cyclohexyl and substituted cyclohexyl.

Examples of the substituted aryl groups include aryl groups substituted with at least one substituent selected from halogens, alkyl groups having 1 to about 8 carbon atoms, acyl groups, or a nitro group. Particularly preferred aryl groups include substituted and unsubstituted phenyl, benzyl, phenalkyl or naphthyl.

Ideally, preferred silyl ester monomers are based on compounds of Formula (IV) in which n is 0, i.e. those of formula X-SiR⁹R¹⁰Rⁿ.

P1612

Examples of monomers containing silyl ester functionality are well known and are described in, inter alia, W02014/064048. Monomers as defined by the general Formula (IV) include:

silyl ester monomers of acrylic acid and methacrylic acid, such as 5 triethylsilyl (meth)acrylate, tri-n-propylsilyl (meth)acrylate, triisopropylsilyl acrylate, tri-n-butylsilyl (meth)acrylate, triisobutyl silyl (meth)acrylate, tri-fe/7butylsilyl (meth)acrylate, tri-sec-butylsilyl (meth)acrylate, tri-n-pentylsilyl (meth)acrylate, triisopentylsilyl (meth)acrylate, tri-n-hexylsilyl (meth)acrylate, tri-n octylsilyl (meth)acrylate, tri-n-dodecyl silyl (meth)acrylate, triphenyl silyl (meth)acrylate, tri-(p-methylphenyl)silyl (meth)acrylate, tribenzylsilyl (meth)acrylate, ethyldimethylsilyl (meth)acrylate, n-propyldimethylsilyl (meth)acrylate, isopropyldimethylsilyl (meth)acrylate, n-butyldimethylsilyl (meth)acrylate, isobutyldimethylsilyl (meth)acrylate, fe/7-butyldimethylsilyl (meth)acrylate, n-pentyldimethylsilyl (meth)acrylate, n-hexyldimethylsilyl (meth)acrylate, neohexyldimethylsilyl (meth)acrylate, thexyldimethylsilyl (meth)acrylate, n-octyldimethylsilyl (meth)acrylate, n-decyldimethylsilyl (meth)acrylate, dodecyldimethylsilyl (meth)acrylate, n-octadecyldimethylsilyl (meth)acrylate, cyclohexyldimethylsilyl (meth)acrylate, phenyldimethylsilyl (meth)acrylate, benzyldimethylsilyl (meth)acrylate, phenethyldimethylsilyl (meth)acrylate, (3-phenylpropyl)dimethylsilyl (meth)acrylate, p-tolyldimethylsilyl (meth)acrylate, isopropyldiethylsilyl (meth)acrylate, n-butyldiisopropylsilyl (meth)acrylate, n-octyldiisopropylsilyl (meth)acrylate, methyldi-n-butylsilyl (meth)acrylate, methyldicyclohexylsilyl (meth)acrylate, methyldiphenylsilyl (meth)acrylate, fe/7-butyldiphenylsilyl (meth)acrylate, nonamethyltetrasiloxy (meth)acrylate, bis(trimethylsiloxy)methylsilyl (meth)acrylate, tris(trimethylsiloxy)silyl (meth)acrylate_and others as described in W02014/064048 and W003/080747.

Properties of the silyl ester copolymer

The polymer containing organosilyl ester groups can be obtained by polymerizing a monomer mixture in the presence of a polymerization initiator by

P1612 _ f various methods such as solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization in a conventional way or by controlled polymerization techniques. In preparing a coating composition using this polymer containing organosilyl ester groups, the polymer is preferably diluted with an organic solvent to give a polymer solution having an appropriate viscosity. From this standpoint, it is desirable to employ solution polymerization.

Examples of the polymerization initiators include azo compounds such as dimethyl 2,2’-azobis(2-methylpropionate), 2,2'-azobis(2-methylbutyronitrile), 2,2'azobis(isobutyronitrile) and l,l'-azobis(cyanocyclohexane) and peroxides such as tert-butyl peroxypivalate, tert-butyl peroxy-2-ethylhexanoate, Zc/V-butyl peroxydiethylacetate, terZ-butyl peroxyisobutyrate, di-tert-butyl peroxide, tert-butyl peroxybenozate, and tertebutyl peroxyisopropylcarbonate, tert-amyl peroxypivalate, tert-amyl peroxy-2-ethylhexanoate, l,l-di(tert-amyl peroxy)cyclohexane and dibenzoyl peroxide. These compounds are used alone or as a mixture of two or more thereof.

Examples of the organic solvent include aromatic hydrocarbons such as xylene, toluene, mesitylene; ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl isoamyl ketone, cyclopentanone, cyclohexanone; esters such as butyl acetate, tert-butyl acetate, amyl acetate, ethylene glycol methyl ether acetate; ethers such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dibutyl ether, dioxane, tetrahydrofuran; alcohols such as n-butanol, isobutanol, benzyl alcohol; ether alcohols such as butoxyethanol, l-methoxy-2-propanol; aliphatic hydrocarbons such as white spirit; and optionally a mixture of two or more solvents. These compounds are used alone or as a mixture of two or more thereof. The copolymer is preferably a random copolymer.

The thus-obtained polymer containing organosilyl ester groups preferably has a weight-average molecular weight of from 5,000 to 70,000, preferably of from 10,000 to 60,000, especially from 20,000 to 60,000. Mw is measured as described in the examples section.

The silyl ester copolymer may be provided as a polymer solution. The polymer solution is desirably regulated so as to have a solid content of from 30 to

P1612 by weight, preferably from 40 to 85% by weight, more preferably from 47 to 75% by weight.

The final antifouling coating composition of the invention preferably comprises 0.5 to 45 wt% (dry solids) of the silyl ester copolymer, such as 1.0 to 30 wt%, in particular 5 to 25 wt% based on the total coating composition.

The copolymer preferably has a glass transition temperature (Tg) of at least 25 °C, preferably at least 28 °C, such as at least 30 °C. In some embodiments the Tg may be at least 35 °C or at least 40 °C, all values being measured according to the Tg test described in the examples section. Values less than 100 °C are preferred, such as less than 75 °C, e.g. less than 60 °C.

An antifouling coating composition of the invention may optionally comprise a mixture of the silyl ester copolymer of the invention and other silyl ester copolymers, for example as described in US 4,593,055, EP 0 646 630, WO 2009/007276 and EP 2 781 567.

Rosin component

Rosin can be used to adjust the self-polishing properties and the mechanical properties of the antifouling coating film. Antifouling coatings of the invention preferably comprise at least 0.5 wt% (dry solids) rosin, such as at least 1 wt%. The upper limit for rosin components may be 25 wt%, such as 15 wt%.

The rosin of use in the invention can be a rosin or derivative thereof such as a salt thereof e.g. as described below. Examples of rosin materials include wood rosin, tall oil rosin and gum rosin; rosin derivatives such as hydrogenated and partially hydrogenated rosin, disproportionated rosin, dimerised rosin, polymerised rosin, maleic acid esters, fumaric acid esters, glycerol esters, methyl esters, pentaerythritol esters and other esters of rosin and hydrogenated rosin, copper resinate, zinc resinate, calcium resinate, magnesium resinate and other metal resinates of rosin and polymerised rosin and others as described in WO 97/44401. Preferred are gum rosin and derivatives of gum rosin.

P1612

In the present invention, the antifouling composition as a whole may comprise 0.5 to 25 wt%, preferably 1 to 15 wt% (dry solids) of a rosin material, preferably 2 to 7 wt%.

The properties of the antifouling coating can be tuned by varying the relative amounts of silyl ester copolymer and rosin components.

In a preferred embodiment therefore the invention provides a binder comprising a silyl ester copolymer as hereinbefore defined and a rosin or derivative thereof.

Other Binder components

In addition to the silyl ester copolymer and optionally the rosin, an additional binder can be used to adjust the properties of the antifouling coating film. Examples of binders that can be used in addition to the silyl ester copolymers and rosins of the invention include:

acid functional polymers of which the acid group is blocked with divalent metals bonded to a monovalent organic residue, for example as described in EP 0 204 456 and EP 0 342 276; or divalent metals bonded to a hydroxyl residue, for example as described in GB 2 311 070 and EP 0 982 324; or amine for example as described in EP 0 529 693;

hydrophilic copolymers for example (meth)acrylate copolymers as described in GB 2 152 947 and poly (A-vinyl pyrrolidone) copolymers and other copolymers as described in EP 0 526 441;

(meth)acrylic polymers and copolymers, in particular acrylate binders, such as poly («-butyl acrylate), poly («-butyl acrylate-co-isobutyl vinyl ether) and others as described in W003/070832 and EP2128208;

vinyl ether polymers and copolymers, such as poly(methyl vinyl ether), poly(ethyl vinyl ether), poly(isobutyl vinyl ether), poly(vinyl chloride-co-isobutyl vinyl ether);

aliphatic polyesters, such as poly(lactic acid), poly(glycolic acid), poly(2hydroxybutyric acid), poly(3-hydroxybutyric acid), poly(4-hydroxyvaleric acid),

P1612 _r _ aprolactone and aliphatic polyester copolymer containing two or more of the units selected from the above mentioned units;

metal containing polyesters for example as described in EP 1 033 392 and EP 1 072 625, provided that the metal is not copper;

alkyd resins and modified alkyd resins; and hydrocarbon resin, e.g. as described in WO2011/092143, such as hydrocarbon resin formed only from the polymerisation of at least one monomer selected from a C5 aliphatic monomer, a C9 aromatic monomer, an indene coumarone monomer, or a terpene or mixtures thereof;

polyoxalates as described in W02009/100908 and other condensation polymers as described in WO 96/14362.

If, in addition to the rosin and silyl ester copolymer, a further binder is present, the weight ratio of silyl copolymer(s): binder may range from 30:70 to 95:5, preferably from 40:60 to 70:30, especially 50:50 to 70:30. These preferred ratios relate to the amount of silyl copolymer(s) and additional binder only, i.e. the rosin is not included.

Especially suitable additional binders are (meth)acrylic polymers and copolymers.

Biocide

The antifouling coating additionally comprises a compound capable of preventing or removing marine fouling on or from a surface. Traditionally an antifouling coating composition contains copper biocides such as metallic copper, cuprous oxide, copper thiocyanate and the like.

The cuprous oxide material has a typical particle diameter distribution of 0.170 pm and an average particle size (d50) of 1-25 pm. The cuprous oxide material may content a stabilizing agent (to prevent surface oxidation). Examples of commercial available cuprous oxide include Nordox Cuprous Oxide Red Paint Grade, Nordox XLT from Nordox AS, Cuprous oxide from Furukawa Chemicals Co., Ltd.; Red Copp 97N, Purple Copp, Lolo Tint 97N, Chemet CDC, Chemet LD from American Chemet Corporation; Cuprous Oxide Red from Spiess-Urania;

P1612 _ _r jus oxide Roast, Cuprous oxide Electrolytic fromTaixing Smelting Plant Co., Ltd.

A series of organic biocides can be used instead of copper biocides such as

4- [l-(2,3-dimethylphenyl)ethyl]-lH-imidazole [medetomidine] and 4-bromo-2-(4chlorophenyl)-5-(trifluoromethyl)-lH-pyrrole-3-carbonitrile [tralopyril]. Any known biocide can be used in the invention. The terms antifouling agent, antifoulant, biocide, toxicant are used in the industry to describe known compounds that act to prevent marine fouling on a surface. The antifouling agents of the invention are marine antifouling agents.

The coating composition may include a copper biocide, preferably cuprous oxide (CU2O) and/or copper pyrithione. The coating compositions of the invention may contain other biocides such as described in WO2014/064048. Preferred biologically active agents are cuprous oxide, copper thiocyanate, zinc pyrithione, copper pyrithione, zinc ethylenebis(dithiocarbamate) [zineb], 2-(fert-butylamino)-4(cyclopropylamino)-6-(methylthio)-l,3,5-triazine [cubutryne], 4,5-dichloro-2-noctyl-4-isothiazolin-3-one [DCOIT], N-dichlorofluoromethylthio-N',N'-dimethyl-Nphenylsulfamide [dichlorofluanid], N-dichlorofluoromethylthio-N',N'-dimethyl-N-ptolylsulfamide [tolylfluanid], 4-[l-(2, 3-dimethylphenyl)ethyl]- 1 H-imidazole [medetomidine], triphenylborane pyridine [TPBP] and 4-bromo-2-(4-chlorophenyl)5- (trifluoromethyl)-ΙΗ-pyrrole-3-carbonitrile [tralopyril],

A mixture of biocides can be used as is known in the art as different biocides operate against different marine fouling organisms.

In a preferred embodiment, the biocide is copper free. In this embodiment, the antifouling agent is preferably an organic antifouling agent, e.g. one selected from the list above. In this embodiment, a preferred biocide combination involves a combination of tralopyril and one or more selected from zinc pyrithione, and 4,5dichloro-2-octyl-4-isothiazolin-3-one.

Where present, the combined amount of biocides may form up to 70 wt% of the coating composition, such as 4 to 60 wt%, e.g. 5 to 60 wt%. Where copper is present, a suitable amount of biocide might be 20 to 60 wt% in the coating composition. Where copper is avoided, lower amounts might be used such as 0.1 to 20 wt%, e.g. 0.2 to 15 wt%.

PI612

Some antifouling agents may be encapsulated or adsorbed on an inert carrier or bonded to other materials for controlled release. These percentages refer to the amount of active antifouling agent present and not therefore to any carrier used.

Other components

In addition to the silyl ester copolymer and any of the optional components described above, the antifouling coating composition according to the present invention may optionally further comprise one or more components selected among other binders, inorganic or organic pigments, extenders and fillers, additives, solvents and thinners.

Examples of pigments are inorganic pigments such as titanium dioxide, iron oxides, zinc oxide and zinc phosphate; organic pigments such as phthalocyanine compounds, azo pigments and carbon black.

Examples of extenders and fillers are minerals such as dolomite, plastorite, calcite, quartz, barite, magnesite, aragonite, silica, wollastonite, talc, chlorite, mica, kaolin and feldspar; synthetic inorganic compounds such as calcium carbonate, magnesium carbonate, barium sulphate, calcium silicate and silica; polymeric and inorganic microspheres such as uncoated or coated hollow and solid glass beads, uncoated or coated hollow and solid ceramic beads, porous and compact beads of polymeric materials such as poly(methyl methacrylate), poly(methyl methacrylateco-ethylene glycol dimethacrylate), poly(styrene-co-ethylene glycol dimethacrylate), poly(styrene-co-divinylbenzene), polystyrene, poly(vinyl chloride).

Examples of additives that can be added to an antifouling coating composition are reinforcing agents, thixotropic agents, thickening agents, antisettling agents, wetting and dispersing agents, plasticizers and solvents.

Examples of reinforcing agents are flakes and fibres. Fibres include natural and synthetic inorganic fibres such as silicon-containing fibres, carbon fibres, oxide fibres, carbide fibres, nitride fibres, sulphide fibres, phosphate fibres, mineral fibres; metallic fibres; natural and synthetic organic fibres such as cellulose fibres, rubber fibres, acrylic fibres, polyamide fibres, polyimide, polyester fibres, polyhydrazide fibres, polyvinylchloride fibres, polyethylene fibres and others as described in WO

P1612 '102. Preferably, the fibres have an average length of 25 to 2,000 pm and an average thickness of 1 to 50 pm with a ratio between the average length and the average thickness of at least 5.

Examples of thixotropic agents, thickening agents and anti-settling agents are silicas such as fumed silicas, organo-modified clays, amide waxes, polyamide waxes, amide derivatives, polyethylene waxes, oxidised polyethylene waxes, hydrogenated castor oil wax, ethyl cellulose, aluminium stearates and mixtures thereof.

Examples of plasticizers are chlorinated paraffins, phthalates, phosphate esters, sulphonamides, adipates and epoxidized vegetable oils.

Examples of dehydrating agents and drying agents include anhydrous calcium sulphate, calcium sulphate hemihydrate, anhydrous magnesium sulphate, anhydrous sodium sulphate, anhydrous zinc sulphate, molecular sieves and zeolites; orthoesters such as trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, triisopropyl orthoformate, tributyl orthoformate, trimethyl orthoacetate and triethyl orthoacetate; ketals; acetals; enolethers; orthoborates such as trimethyl borate, triethyl borate, tripropyl borate, triisopropyl borate, tributyl borate and tri-fe/7-butyl borate; silicates such as trimethoxymethyl silane, tetraethyl silicate and ethyl polysilicate; and isocyanates, such as p-toluenesulfonyl isocyanate.

The preferred dehydrating agents and drying agents are silicates and the inorganic compounds.

Examples of stabilizers that contribute to the storage stability of the antifouling coating composition are carbodiimide compounds, such as bis(2,6dii sopropylphenyl)carbodiimide and poly(1,3,5 -trii sopropylphenylene-2,4carbodiimide) and others as described in patent EP 2725073.

In general, any of these optional components can be present in an amount ranging from 0.1 to 20 wt%, typically 0.5 to 20 wt%, preferably 0.75 to 15 wt% of the antifouling composition. It will be appreciated that the amount of these optional components will vary depending on the end use.

It is highly preferred if the antifouling composition contains a solvent. This solvent is preferably volatile and is preferably organic. Examples of organic solvents and thinners are aromatic hydrocarbons such as xylene, toluene, mesitylene; ketones

P1612

_... as methyl ethyl ketone, methyl isobutyl ketone, methyl isoamyl ketone, methyl amyl ketone, diisobutyl ketone, methyl propyl ketone, cyclopentanone, cyclohexanone; esters such as butyl acetate, tert-butyl acetate, amyl acetate, isoamyl acetate, ethylene glycol methyl ether acetate, propyl propionate, butyl propionate; ethers such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dibutyl ether, dioxane, tetrahydrofuran, alcohols such as //-butanol, isobutanol, benzyl alcohol; ether alcohols such as butoxyethanol, l-methoxy-2-propanol; aliphatic hydrocarbons such as white spirit; and optionally a mixture of two or more solvents and thinners.

Preferred solvents are aromatic solvents, especially xylene and mixtures of aromatic hydrocarbons.

The amount of solvent is preferably as low as possible. The solvent content may be up to 50 wt% of the composition, preferably up to 30 wt% of the composition, such as up to 20 wt% but may be as low as 10 wt% or less, e.g. 8.0 wt% or less. Again, the skilled man will appreciate that the solvent content will vary depending on the other components present and the end use of the coating composition.

Alternatively the coating can be dispersed in an organic non-solvent for the film-forming components in the coating composition or in an aqueous dispersion.

The antifouling coating composition of the invention should preferably have solids content above 40 vol%, e.g. above 45 % by volume, such as above 50 vol%, preferably above 55 vol% (ASTMD5201-01).

More preferably the antifouling coating composition should have a content of volatile organic compounds (VOC) below 500 g/L, preferably below 400 g/L, e.g. below 390 g/L. VOC content can be calculated (ASTM D5201-01) or measured, preferably measured.

The antifouling coating composition of the invention can be applied to a whole or part of any object surface which is subject to marine fouling. The surface may be permanently or intermittently underwater (e.g. through tide movement, different cargo loading or swell). The object surface will typically be the hull of a vessel or surface of a fixed marine object such as an oil platform or buoy. Application of the coating composition can be accomplished by any convenient

P1612 . s, e.g. via painting (e.g. with brush or roller) or spraying the coating onto the object. Typically the surface will need to be separated from the seawater to allow coating. The application of the coating can be achieved as conventionally known in the art.

When applying the antifouling coating to an object (e.g a ship hull) the surface of the object is typically not protected solely by a single coat of antifouling. Depending on the nature of the surface the antifouling coating can be applied directly to an existing coating system. Such a coating system may comprise several layers of paint of different generic types (e.g. epoxy, polyester, vinyl or acrylic or mixtures thereof). If the surface is a clean and intact antifouling coating from a previous application, the new antifouling paint can be applied directly, typically as one or two coats with more in exceptional cases.

Alternatively, the artisan may start with an uncoated surface (e.g. steel, aluminium, plastic, composite, glass fiber or carbon fiber). To protect such a surface, the full coating system will typically comprise one or two layers of an anticorrosive coating, one layer of tie-coat and one or two layers of antifouling paint. The person skilled in the art will be familiar with these coating layers.

In exceptional cases additional antifouling paint layers may be applied.

In a further embodiment therefore the invention provides a substrate having coated thereon an anticorrosive coating layer such as an epoxy primer, a tie layer and an antifouling coating composition as herein defined.

The invention will now be defined with reference to the following non limiting examples.

Examples

Materials and methods

AMBN 2,2 ’ - Azobi s(2-methylbutyronitrile) n-BA n-Butyl acrylate

EDEGA Ethyl diethyleneglycol acrylate

MMA Methyl methacrylate

MEMA 2-Methoxyethyl methacrylate

P1612

V	Tetrahydrofurfuryl acrylate
THFMA	Tetrahydrofurfuryl methacrylate
TISMA	Triisopropylsilyl methacrylate
n.d.	Not determined
Methods

Testing

Non-volatile matter content

The non-volatile matter content in the polymer solutions are determined in accordance with ISO 3251. A test sample of 0.5 g ± 0.1 g are taken out and dried in a ventilated oven at 150 °C for 30 minutes. The weight of the residual material is considered to be the non-volatile matter (NVM). The non-volatile matter content is expressed in weight percent. The value given is the average of three parallels.

Molecular weight determination

The polymers are characterised by Gel Permeation Chromatography (GPC) measurement. The molecular weight distribution (MWD) was determined using a Polymer Laboratories PL-GPC 50 instrument with two PLgel 5 pm Mixed-D columns from Polymer Laboratories in series, tetrahydrofuran (THF) as eluent at ambient temperature and at a constant flow rate of 1 mL/min and with a refractive index (RI) detector. The columns were calibrated using polystyrene standards EasiVials PS-H from Polymer Laboratories. The data were processed using Cirrus software from Polymer Labs.

Samples were prepared by dissolving an amount of polymer solution corresponding to 25 mg dry polymer in 5 mL THF. The samples were kept for minimum 3 hours at room temperature prior to sampling for the GPC measurements. Before analysis the samples were filtered through 0.45 pm Nylon filters. The weight-average molecular weight (Mw) and the number-average molecular weight (Mn) were determined, and the results are reported as Mw and the polydispersity index (PDI), given as Mw/Mn.

Viscosity

P1612 . iscosities of the polymer solutions are determined in accordance with ASTM D2196 Test method A using a Brookfield DV-I viscometer with LV-2 or LV-4 spindle at 12 rpm. The polymers are tempered to 23.0 °C ± 0.5 °C before the measurements.

Glass transition temperature Tg

The glass transition temperature (Tg) is obtained by Differential Scanning Calorimetry (DSC) measurements. The DSC measurements were performed on a TA Instruments DSC Q200. Samples were prepared by transfer of a small amount of polymer solution to an aluminium pan and dry the samples for minimum 10 h at 50 °C with subsequent 3 h at 150 °C. The samples of approx. 10 mg dry polymer material were measured in open aluminium pans with an empty pan as reference.

The temperature program for the measurement was as follows:

1. Equilibration at -50 °C

2. Heating ramp 10 °C/min to 150 °C

3. Cooling ramp -10 °C/min to -50 °C

4. Heating ramp 10 °C/min to 150 °C

The data were processed using Universal Analysis software from TA Instruments. The inflection point of the glass transition range, as defined in ASTM E1356-08, of the second heating is reported as the Tg of the polymers.

Real life dynamic testing

A PVC-panel was coated with first one coat of tie coat (Safeguard Plus), then one coat of commercial antifouling coating (SeaQuantum Ultra S). The paints to be tested were applied to the PVC-panel using a frame applicator with 600 pm gap size. The panel was then mounted to the hull of a ship. The ship was sailing in a worldwide trade for 15 months, average speed 15 knots, voyage factor 75%, longest stop 9 days. The results from the test are reported as the amount of fouling on a scale from 0 to 4 according to the table below.

Each paint film had a thin stripe with a non-polishing reference i.e. a paint that does not polish. The film thickness reduction was determined by measuring the difference

P1612 n thickness between the exposed paint and the paint that was covered by the non-polishing reference.

Rating	Area covered by fouling (algea)
0	Less than 5%
1	5-20%
2	20-50%
3	50-80%
4	More than 80%

Konig pendulum hardness

The pendulum hardness was measured according to ISO 1522 using an Erichsen pendulum hardness tester model 299/300 with a Konig pendulum. The paints were applied to glass panels using a frame applicator with 300 pm gap size. The pendulum hardness was first measured after drying at 23 °C/50% relative humidity for 24 h. Then the panels were dried further at 50 °C for 72 h and then equilibrated at 23 °C before the pendulum hardness was measured again. The hardness is quantified as the number of pendulum oscillations to damp the amplitude from 6° to 3°.

General procedure for preparation of copolymer solutions A-l to A-14 and C-l to C6

Xylene (35 parts) is charged to a reactor fitted with a stirrer, a condenser, a feed inlet and a nitrogen inlet. The reactor content is heated to 85 °C and maintained at this temperature. The feed, which consists of a mixture of monomers (50 parts), xylene (10 parts) and 2,2’-azobis(2-methylbutyronitrile) (AMBN) (0.48 parts), is added to the reactor at a constant rate over 2 hours. One hour after the feed addition is complete, a mixture of xylene (5 parts) and AMBN (0.12 parts) is added. The reaction mixture is kept at 85 °C for another two hours before the temperature is increased to 120 °C and kept at this temperature for 30 minutes. Finally the reactor

P1612 . _ )led. The monomer compositions of the polymers are listed in Table 1 and Table 2.

General procedure for preparation of copolymer solutions A-15

Xylene (30.0 parts) is charged to a reactor fitted with a stirrer, a condenser, a feed inlet and a nitrogen inlet. The reactor content is heated to 95 °C and maintained at this temperature. The feed, which consists of a mixture of monomers (55.0 parts), xylene (8.5 parts) and 2,2’-azobis(2-methylbutyronitrile) (AMBN) (0.52 parts), is added to the reactor at a constant rate over 2 hours. One hour after the feed addition is complete, a mixture of xylene (7.0 parts) and AMBN (0.13 parts) is added. The reaction mixture is kept at 95 °C for another 1.5 hours before the temperature is increased to 105 °C and kept at this temperature for 30 minutes. Finally, the reactor is cooled. The monomer compositions of the polymers are listed in Table 2.

General procedure for preparation of antifouling coating compositions

The components were mixed in the proportions given in Table 3 and Table 4. The mixture was dispersed in the presence of glass beads (approx. 2mm in diameter) in a paint can of 250 ml using a vibrational shaker for 15 minutes.

As can be seen from Tables 3 and 4, coating compositions according to the invention showed an increased polishing rate in terms of film thickness reduction. Significantly, the fouling rating of the examples was also excellent. The examples show therefore that the compositions of the invention possess ideal antifouling properties.

P1612

A-13	29.8	10.1		10.3	6.0	43.8	50.2	45.45	9.90		12.25	4.85	27.55	50.8	380	29.0	46	4.5
A-12	34.7	5.4	29.1		CO cS	21.0	69.2	50.00	5.00	25.00		7.50	12.50	50.9	305	33.1	33	3.2
A-ll	35.0	30.0				35.0	65.0	50.89	28.10				21.02	51.4	345	34.7	36	3.7
A-10	30.0	22.5			10.0	37.5	52.5	45.96	22.21			8.10	23.73	50.9	380	33.5	i—l	3.5
A-9	30.0	25.0				45.0	55.0	46.38	24.90				28.73	51.4	530	41.6	i—l	4.0
CO <	35.0	15.0			7.5	42.5	50.0	52.89	14.60			5.99	26.52	49.7	257	43.1	32	3.2
A-7	35.0	15.0			20.0	30.0	50.0	51.75	14.29			15.64	18.32	51.5	280	31.5	37	3.6
A-6	35.0	30.0			O'OI	25.0	65.0	50.04	27.63			7.56	14.76	52.1	307	27.5	40	3.6
A-5	35.0	22.5				42.5	57.5	52.20	21.62				26.18	49.6	280	43.7	33	3.4
A-4	35.0	22.1			9.6	33.3	57.1	51.43	20.90			7.44	20.23	51.5	272	34.6	36	3.6
A-3	25.0	30.0				45.0	55.0	39.74	30.72				29.54	50.4	400	36.4	37	3.6
A-2	35.0	30.0				35.0	65.0	50.89	28.10				21.02	51.5	337	38.9	36	3.5
A-l	30.0	30.0			10.0	30.0	60.0	44.77	28.84			ΟΊ CO	18.49	51.8	305	26.7	43	3.8
	TISMA (a)	THFA (b)	MEMA (c)	EDEGA (c)	n-BA	< z z	Sum a+b+c	TISMA	THFA	< Σ LLI Σ	EDEGA	n-BA	< Σ Σ	Solid content, %	Viscosity, cP	u 0 cn H	Mw xlOOO	PDI
Monomers	Mol%		Weight%	Polymer solution properties	Polymer properties

P1612

Table 2. Copolymers (Columns marked C are comparative).

C-6	28.0		25.0	24.8	22.2	53.0	41.28		25.88	19.33	13.52	50.8	387	34.1	44	3.7
C-5	31.5		21.0	23.5	24.0	52.5	45.93		21.50	18.12	14.45	49.8	to f\l	33.7	38	3.5
C-4	35.0		17.0	30.0	18.0	52.0	co cS		17.00	22.58	10.58	49.7	205	26.6	37	3.5
C-3	25.0	20.0		20.0	35.0	45.0	39.74	20.48		16.81	22.98	48.9	182	20.3	LD ΓΟ	3.6
C-2	25.0	15.0		12.5	47.5	40.0	41.06	15.87		10.85	32.22	51.2	465	40.1	37	3.5
C-l	30.0	15.0		20.0	35.0	45.0	46.37	14.94		16.34	22.34	51.5	282	28.5	LD ΓΟ	3.6
A-15	34.5	20.0		11.7	33.8	54.5	51.09	19.08		9.16	20.67	54.7	324	33.7	24	2.9
A-14	35.0	20.0		20.0	25.0	55.0	50.88	18.73		15.37	15.01	51.2	210	23.8	38	3.6
	TISMA (a)	THFA (b)	THFMA (d)	n-BA	< z z	Sum a+b+d	TISMA	THFA	THFMA	n-BA	< z z	Solid content, %	Viscosity, cP	u 0 cn H	Mw x 1000	PDI
Monomers	Mol%		Weight%	Polymer solution properties	Polymer properties

P1612

Table 3. Paint formulations (of invention). Ingredients in parts by weight.

Examples, paints	B-15															31.50	7.00	1.40		0.80	o ό
B-14														23.44		5.00	1.00	1.00	0.50		50.00
B-13													23.62			5.00	1.00	1.00	0.50		50.00
B-12												23.58				5.00	1.00	1.00	0.50		50.00
B-ll											23.35					5.00	1.00	1.00	0.50		50.00
B-10										23.58						5.00	1.00	1.00	0.50		50.00
B-9									23.35							5.00	1.00	1.00	0.50		50.00
B-8								24.14								5.00	1.00	1.00	0.50		50.00
B-7							23.30									5.00	1.00	1.00	0.50		50.00
B-6						23.03										5.00	1.00	1.00	0.50		50.00
B-5					24.19											5.00	1.00	1.00	0.50		50.00
B-4				23.30												5.00	1.00	1.00	0.50		50.00
B-3			23.81													5.00	1.00	1.00	0.50		50.00
B-2		23.30														5.00	1.00	1.00	0.50		50.00
B-l	23.17															5.00	1.00	1.00	0.50		50.00
	A-l	A-2	A-3	A-4	A-5	A-6	A-7	CO <	A-9	A-10	A-ll	A-12	A-13	A-14	A-15	Rosin solution, 60% in xylene (gum rosin)	Disparlon A603-20X	Disparlon 4401-25X	Tetraethoxysilane	Wetting and dispersing agent	Cuprous oxide

P1612

Examples, paints	B-15		2.50	2.80	5.90		6.90	15.20	18.20	7.50		CT>	70	104	o
B-14	2.00			1.50	0.50	4.50	4.50		6.06		f\l i—l	CO to	28	f\l
B-13	2.00			1.50	0.50	4.50	4.50		CO co LiS		i—l i—l	co to	09	O
B-12	2.00			1.50	0.50	4.50	4.50		5.92	f\l i—l	70	CT> LD	o
B-ll	2.00			1.50	0.50	4.50	4.50		6.15	tO i—l	73	CO	o
B-10	2.00			1.50	0.50	4.50	4.50		5.92	i—l	72	39	o
B-9	2.00			1.50	0.50	4.50	4.50		6.15	CO i—l	LD	i—l	o
B-8	2.00			1.50	0.50	4.50	4.50		5.36	20	76	co	o
B-7	2.00			1.50	0.50	4.50	4.50		6.20	i—l	69	32	i—l
B-6	2.00			1.50	0.50	4.50	4.50		6.47	f\l i—l	64	47	o
B-5	2.00			1.50	0.50	4.50	4.50		5.31	i—l f\l	77	ΟΊ LD	o
B-4	2.00			1.50	0.50	4.50	4.50		6.20	tO i—l	74	46	o
B-3	2.00			1.50	0.50	4.50	4.50		5.69	LD i—l	73	CO LD	o
B-2	2.00			1.50	0.50	4.50	4.50		6.20	CO i—l	76	74	o
B-l	2.00			1.50	0.50	4.50	4.50		6.33	f\l i—l	70	CO	o
	Copper pyrithione	Zinc pyrithione	Tralopyril	Iron oxide red	Titanium dioxide	Talc	Zinc oxide	Zinc phosphate	Xylene	Pendulum hardness 24h 23 °C	Pendulum hardness 72h 50 °C	Film thickness reduction, pm	Rating, fouling

P1612

Table 4. Paint formulations (comparative). Ingredients in parts by weight.

Example no.	D-l	D-2	D-3	D-4	D-5	D-6
C-l	23.30
C-2		23.44
C-3			24.54
C-4				24.14
C-5					24.1
C-6						23.62
Rosin solution, 60% in xylene (gum rosin)	5.00	5.00	5.00	5.00	5.00	5.00
Disparlon A603-20X	1.00	1.00	1.00	1.00	1.00	1.00
Disparlon 4401-25X	1.00	1.00	1.00	1.00	1.00	1.00
Tetraethoxysilane	0.50	0.50	0.50	0.50	0.50	0.50
Cuprous oxide	50.00	50.00	50.00	50.00	50.00	50.00
Copper pyrithione	2.00	2.00	2.00	2.00	2.00	2.00
Iron Oxide red	1.50	1.50	1.50	1.50	1.50	1.50
Titanium dioxide	0.50	0.50	0.50	0.50	0.50	0.50
Talc	4.50	4.50	4.50	4.50	4.50	4.50
Zinc Oxide	4.50	4.50	4.50	4.50	4.50	4.50
Xylene	6.20	6.06	4.96	5.36	5.40	5.88
Pendulum hardness 24h 23°C	13	16	11	17	16	16
Pendulum hardness 72h 50°C	69	73	71	78	71	72
Film thickness reduction, pm	25	30	16	16	23	16
Rating, fouling	4	3	4	4	3	4

P1612

Claims

1. A silyl ester copolymer comprising as comonomers:

(a) triisopropyl silyl methacrylate (TISMA));

5 (b) one or more compounds of Formula (I)

O wherein R1 is a cyclic ether (such as oxolane, oxane, dioxolane, dioxane 10 optionally alkyl substituted) and W is a C1-C4 alkylene; and optionally (c) one or more comonomers of Formula (II):

(II) wherein R2 is H or CH3, and R3 is a C3-C18 substituent comprising at least 15 one oxygen or nitrogen atom, preferably at least one oxygen atom; and wherein the sum of the mole fractions of (a)+(b)+(c) in the copolymer is > 50 mol%.

2. A silyl ester copolymer as claimed in claim 1 comprising as comonomers

20 (b): one or more of tetrahydrofurfuryl acrylate,

Isopropylideneglycerol acrylate, Glycerolformal acrylate, or Cyclic trimethylolpropane formal acrylate.

3. A silyl ester copolymer as claimed in any preceding claim comprising as 25 comonomer (b):tetrahydrofurfuryl acrylate (THFA);

4. A silyl ester copolymer according to any preceding claim wherein the silyl ester copolymer has a glass transition temperature (Tg) of at least 25 °C as measured by DSC according to the method of the examples section.

5. A silyl ester copolymer according to any preceding claim wherein the amount of (a) in the silyl ester copolymer is in the range of 15 to 70 mol%, preferably in the range of 20 to 60 mol%, more preferably in the range of 25 to 50 mol%.

6. A silyl ester copolymer according to any preceding claim wherein the amount of (b) in the silyl ester copolymer is in the range of 2 to 50 mol%, preferably in the range of 3 to 40 mol%, more preferably in the range of 5 to 35 mol%.

7. A silyl ester copolymer according to any preceding claim wherein one or more of said comonomers (c) has an R3 group of formula (CH2CH2O)n-R4 where R4 is a C1-C10 alkyl or C6-C10 aryl substituent and n is an integer in the range of 1 to 6, preferably 1 to 3.

8. A silyl ester copolymer according to any preceding claim wherein one or more of said comonomers (c) is present and has an R2 group of formula (CH2CH2O)n-R4 where R4 is aCl-ClO alkyl substituent, preferably methyl or ethyl, and n is an integer in the range of 1 to 3, preferably 1 or 2.

9. A silyl ester copolymer according to any preceding claim wherein the comonomer(s) (c) include one or more of methoxy ethyl methacrylate (MEMA) and ethyl diethyleneglycol acrylate (EDEGA).

10. A silyl ester copolymer according to any preceding claim further comprising one or more comonomers of Formula (III):

wherein R5 is H or CH3, and R6 is a C1-C8 hydrocarbyl substituent, preferably a ClC8 alkyl substituent, most preferably methyl, ethyl, n-propyl, 2-ethylhexyl or nbutyl.

11. A silyl ester copolymer according to any preceding claim where said comonomer(s) of Formula (III) are present and include one or more of methyl methacrylate (MMA) and n-butyl acrylate (n-BA).

12. A silyl ester copolymer according to any preceding claim including methyl methacrylate (MMA) as a comonomer in an amount of 10 to 50 mol%, preferably 15 to 45 mol%.

13. A silyl ester copolymer according to any preceding claim including n-butyl acrylate (n-BA) as a comonomer in an amount of 5 to 30 mol%, such as 5 to 20 mol%.

14. A binder for an anti-fouling coating composition comprising a silyl ester copolymer as claimed in any of claims 1 to 13 and a rosin or derivative thereof.

15. An antifouling coating composition comprising the silyl ester copolymer according to any of claims 1 to 13 and at least one marine antifouling agent.

16. An antifouling coating composition as claimed in claim 15 wherein said marine antifouling agent is free of copper.

17. An antifouling coating composition according to claim 15, wherein said marine antifouling agent comprises a copper compound.

18. A process for protecting an object from marine fouling, said process comprising coating at least a part of said object which is subject to fouling with an antifouling coating composition as claimed in any of claims 15 to 17.

19. An object coated with the antifouling coating composition as claimed in any of claims 15 to 17.

20. An object as claimed in claim 19 wherein the object is coated with an

10 anticorrosive coating layer, a tie layer and an antifouling coating composition as claimed in claim 15 to 17.

21. An object as claimed in claim 19 wherein the object is coated with an antifouling coating composition as claimed in claims 15 to 17 which covers a pre15 existing antifouling coating composition on the substrate.

Intellectual

Property

Office

Application No: GB1718577.8 Examiner: Dr Albert Mthupha