GB2273934A

GB2273934A - Improvements in and relating to polymeric resins and binders for antifouling paints

Info

Publication number: GB2273934A
Application number: GB9325108A
Authority: GB
Inventors: Ursula Gerigk; Dirk Ventur
Original assignee: Witco GmbH
Current assignee: Lanxess Organometallics GmbH
Priority date: 1992-12-14
Filing date: 1993-12-08
Publication date: 1994-07-06
Anticipated expiration: 2013-12-08
Also published as: DE4242082A1; GB2273934B; GB9325108D0

Description

2273934 Improvements in and relating to polymeric resins and binders for

antifouling paints The present invention relates to tin-free, watersoluble, slowly hydrolysable, polymeric binder systems which optionally in combination with biocides - can be used for protecting underwater surfaces from fouling by marine organisms.

Under suitable conditions, surfaces that come into contact with sea-water, such as, for example, boats, ships, drilling platforms, nets or underwater pipelines, very quickly become covered with marine organisms, such as, for example, algae, seaweed, shells, tube-worms, fungi, etc..

In many cases, fouling of underwater surfaces by such organisms leads to increased maintenance costs, and in the case of ships - owing to the increased frictional resistance in the water when the hull is fouled - to a marked reduction in speed or to a corresponding increase in fuel consumption. 20 Therefore, in order to prevent the surfaces from becoming fouled, the surface is in many cases protected by the application of a paint system containing suitable antifouling substances. The antifouling substances are released from the paint system through contact with sea-water and are thus able to develop their activity against marine organisms.

In order to achieve protection that is as long-lasting as possible against the possible surface colonising organisms, continuous release of the antifouling substance from the paint system in metered amounts is 5 sought.

In general, those paint systems - which are frequently also called antifouling systems or antifouling compositions - consist of a biocidal or non-biocidal polymeric binder, co-biocides and pigments.

Poly(meth)acrylates, polyesters, epoxy compounds, chlorine rubber, resins or other, film-forming systems are often used as polymeric binders.

The most successful antifouling paints in recent years have been socalled self-polishing paints, which use binder systems in which the side groups of a linear polymer unit are split off in a first step by reaction with sea-water, the polymer framework that remains becoming water-soluble or water-dispersible as a result.

In a second step, the water-soluble portion of the whole polymer is washed out of or eroded from the paint surface by the movement of the ship or of the surrounding water, a fresh surface which can again enter into a reaction with sea-water being provided at the same time. Such paint systems are described, for example, in GB 1 124 297 and GB 1 457 590.

The advantage of those paint systems lies in the controlled rate of release of the incorporated biocides, with the simultaneous formation of new, smooth surfaces.

The only binder systems having the above-mentioned properties which are relatively significant commercially are copolymers of triorganotin esters - especially tri5 n-butyltin esters - of olefinically unsaturated carboxylic acids. In many cases, substituted (meth)acrylic acids are used as unsaturated carboxylic acids.

In addition to the biocidal activity of the organotin group against marine organisms, those organotin- containing binder systems are distinguished especially by the above- mentioned controllable hydrolysability in sea-water.

The fact that the underwater surfaces are as a result free from fouling owing to controllable rates of release of the biocides and pigments used, and the simul- taneous continuous polishing of the surfaces by the splitting off of the water-soluble portions of the polymer framework, are an important economic advantage of those systems.

The use of organotin-based antifouling systems especially in the yachting field, where such a powerful biocidal activity as that exhibited by the tri-n-butyltin compounds is unnecessary, has recently been the subject of lively discussion, and some countries have already considerably restricted or even forbidden the use of organotin-based systems in the yachting field.

There is therefore a corresponding need in that 4 - field for alternative paint systems that dissolve slowly in water.

Various groups which likewise contain radicals that are hydrolysable in sea-water are mentioned in the literature as potential substitutes for the triorganotin compounds. However, they have not as yet become widely used commercially.

For example, WO 84/02915 mentions a number of possible groups which are said to form readily hydrolysable ester bonds with polymers containing carboxylic acid. EP-A-0 131 626, EP-A-0 201 279, EP-A-0 204 444, EP-A-0 204 456, EP-A-0 232 006, EP-A-0 289 481 and EP-A-0 343 897 also describe water-soluble polymer systems, some of which are self-polishing or erodable in contact with water.

In a number of patent applications and patents (inter alia EP-A-0 113 038, EP-A-0 161 881, EP-A-0 250 325, EP-A-0 256 312, EP-A-0 419 654, EP-A-0 428 970, EP-A-0 464 957), processes for the preparation of quater- nisation products of tertiary aminoalkylamides of acrylic and methacrylic acids, or the use of the polymeric, tertiary or quaternary aminoalkylamides as dispersing, flocculating or water-purifying agents or as adsorbent material for the liberation of water-soluble organic compounds, are described. The use of cyclic tertiary amides or imides as non-reactive components of antifouling binder systems is mentioned in EP- A-0 289 481.

- 5 The present invention describes a novel binder system suitable for use in water-soluble, slowly hydrolysable antifouling systems.

By copolymerisation of a monomeric unit of the 5 general formula (1) Ri R2 1 - 1 - (1) CH2, =C-C-N (-C-);, -R,4 1 1 1 0 H R3 with a suitable comonomer, it is possible to prepare the hydrolysable polymeric resins according to the invention of the general formula (2) Rt [-CH2 -C-] - (2) 1 C=0 (R2 -L-t(z j p 1 in which R4 R1 is H or CH3 R2 is selected from H and Cl-C4-alkyl groups R3 is selected from H and Cl-C4-alkyl groups 15 p is from 0 - 4 R4 is either (CH2)n (Y)m (CH2)o CR5R6R7 X- wherein n is from 0 - 6 6 m is 0 or 1 Y is selected from substituted phenyl rings of the general formula C6H2R8R9 wherein R8, R9 may be the same or different and each is 5 selected from H, CH3, Br, Cl, N02, CN 0 is from 0 - 2 R5, R6, R7, which may be the same or different, are each selected from H, linear or branched Cl-C18-alkyl groups, and substituted benzyl groups of the type -CH2-CO4R10 wherein R10 = H, Cl, Br, I, N02, CN, CH3 X is selected f rom Br, Cl, I or (CH2)qCOOR11 wherein R,, is selected f rom. H, Cl-C6-alkyl groups, and unsubstituted and monosubstituted benzyl and phenyl groups with one or more substituents selected from H, Cl, Br, I, N02, W and CH3 q is from 0 - 2 and B is a constituent unit derived from a previously ethylenically unsaturated monomer, said unit being present in a percentage of > 80 % by weight, based on the total polymer.

The invention provides polymeric resins of general formula (2).

The invention provides also hydrolysable prepolymeric resins of the general formula (2) in which Rl is CH3, R2 and R3 are each H and in which in R4 the radicals R5 and R6 are each CH3 and R7 is a benzyl radical, with n = 2, m = 0, o = 0 and p = 1.

The invention further provides a polymeric binder system for an antifouling paint for protecting maritime surfaces, which system consists essentially of a) a polymeric resin of the general formula (2) and, optionally, b) co-biocides and, optionally, c) customary auxiliaries, additives, pigments, plasti- cisers, levelling agents.

Moreover, the invention provides an antifouling paint comprising a hydrolysable polymeric resin which is the copolymerisation product of (i) a compound of the formula R1 0 1 11 CH2 = C-C-NH-R in which the group R is a group comprising a quaternary ammonium or an ester group and the group R1 is H or CH3; and (ii) an ethylenically unsaturated monomer, the proportion by weight in the copolymerisation product constituted by units derived from the ethylenically unsaturated monomer being not less than 80% by weight based on the total weight of the copolymerisation product. The group R is preferably a hydrocarbyl moiety to which a quaternary ammonium group is attached, the hydrocarbyl group optionally comprising one or more further substituents. The hydrocarbyl moiety may be an alkylene chain having up to nine carbon atoms in the chain, that may optionally be substituted by up to two Cl-C4- alkyl groups. The hydrocarbyl group may be an alkylene chain having up to nine carbon atoms in the chain, which may be interrupted by, or have at a terminal position, a phenyl group which may optionally have one or more substituents selected from the group consisting of CH3, Br, Cl, N02 and CN. The group R may be an alkylene chain having a terminal carboxylic ester group, the alkylene chain having up to three carbon atoms in the chain and optionally being substituted by one or more Cl-C4-alkyl groups.

The comonomers B used concomitantly according to the invention are ethylenically unsaturated monomers, such as, for example, acrylates or methacrylates, styrenes, acrylonitriles or vinyl compounds, but preferably a monomeric acrylate or methacrylate compound, such as, for example, methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, acrylamide.

In order to increase the water solubility and hydrolysability of the binder system as a whole, up to 10 % of the total amount of comonomer B 'may be replaced by acrylic acid or alkylacrylic acid wherein alkyl represents a branched or unbranched Cl-C8 group, or by corresponding alkyl acrylates with hydroxy groups.

The binder system according to the invention may be prepared by radical or ionic copolymerisation of the corresponding amide compound with the comonomers.

In dependence upon the solubility properties of the starting monomers, there may be used as radical initiator, for example, benzoyl peroxide, azoisobutyronitrile, ammonium persulphate, 2,2-azo-bis-(2-amidinopropane) dihydrochloride (concentration employed: 0.01 - 2 % by weight of the amount of monomer used) in a suitable solvent, such as, for example, toluene, xylene, cyclohexane, aliphatic hydrocarbons, such as, for example, hexane or heptane, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, gasoline, water, dimethylformamide, dimethyl sulphoxide, ethers (e.g. ethylene glycol dimethyl ether, diethylene glycol dimethyl ether), or mixtures of those solvents with one another (e.g. butanol/Solvesso 100 1:1).

For the purpose of copolymerisation, the starting materials and the initiator are heated in a suitable solvent under nitrogen or are added dropwise to the heated solvent.

In dependence upon the composition by percentage of the starting mixture, the reaction time, the rate of addition and the amount of initiator - and optionally, also by the addition of suitable inhibitors, such as, for example, mercaptans - it is possible to synthesise polymeric binder systems having different compositions and different molecular weights in the range of approximately from 50,000 to 150,000.

In the following, Examples 4 to 12 illustrate the invention. Examples 1 to 3 are Comparative Examples.

Examples Example 1 300.3 g of methyl methacrylate (MMA), 255.5 g of dimethylaminopropyl-methacrylamide (DMAPMA) and 536.1 g of xylene are mixed together and de-aerated with nitrogen. Then 8.9 g of azoisobutyronitrile (AIBN) are added and the solution is copolymerised for 4 hours at 80C in a nitrogen atmosphere, with stirring. A 50 % solution having a viscosity of 0.97 Pa.s is formed.

Example 2 150.1 g of methyl methacrylate (MMA), 213.3 g of butyl methacrylate (BRA), 255.5 g of dimethylaminopropyl-methacrylamide (DHAPMA) and 536.1 g of xylene are mixed together under nitrogen. After the addition of 8.9 g of azoisobutyronitrile (AIBN), the solution is heated to 800C and copolymerised for 4 hours. A 50 % solution having a viscosity of 1.01 Pa. s is formed.

Example 3

10: 150.1 g of methyl methacrylate (MMA), 156.2 g of styrene -(STY), 255. 5 g of dimethylaminopropyl-methacrylamide (DMAPMA), 8.9 g of azoisobutyronitrile (AIBN) and 536.1 g of xylene are mixed together and de-aerated with nitrogen. The mixture is copolymerised for 4 hours at 80'C in a stream of nitrogen, with stirring. A 50 % - solution having a viscosity of 0.99 Pa.s is formed.

Example 4

Within a period of one hour, 126.6 g of benzyl chloride are slowly added dropwise, with stirring, to a solution, 2D which is heated to 700C, of 170 g of dimethylamino propyl-methacrylamide (DMAPMA) and 296.6 g of butanol.

The solution is stirred for a further hour at 70C and then cooled.

Example 5

Within a period of one hour, 141.9 9 of methyl iodide are slowly added dropwise, with stirring, to a solution, which is heated to 700C, of 170 g of dimethylamino- propyl-methacrylamide (DMAPMA) and 296.6 g of butanol. The solution is stirred for a further hour at 70'C and then cooled.

Example 6 80 g of a 50 % solution of the quaternary ammonium compound (Example 4) in butanol are mixed together with 360 g of MMA, 9 g of dibenzoyl peroxide and a mixture of 260 g of butanol and 300 g of Solvesso 100, and the mixture is de-aerated with nitrogen. The mixture is copolymerised for 4 - 5 hours at 800C in a stream of nitrogen, with stirring. A 40 % solution having a viscosity of 9.7 Pa.s and a quaternary active ingredient content (percentage of the NR4 + group in the total polymer) of 10 % is formed.

Example 7

80 g of a 50 % solution of the quaternary ammonium compound (Example 5) in butanol are mixed together with 360 g of MMA, 9 g of dibenzoyl peroxide and a mixture of 260 g of butanol and 300 g of Solvesso 100, and the mixture is de-aerated with nitrogen. The mixture is copolymerised for 4 5 hours at BOOC in a stream of nitrogen, with stirring. A 40 % solution having a viscosity of 9.7 Pa.s and a quaternary active ingredient content (percentage of the NR4 + group in the total polymer) of 10 % is formed.

Example 8 80 g of the quaternary ammonium compound (50 % solution in butanol) of Example 4 are mixed together with 288 g of MMA, 72 g of butyl methacrylate, 8.6 g of dibenzoyl peroxide and a mixture of 260 g of butanol and 300 g of 1Q Solvesso 100. The mixture is copolymerised for 4 5 hours at 80'C in a stream of nitrogen, with stirring. A 40 % solution having a viscosity of 8 Pa.s and an active ingredient content of 10 % is formed.

Example 9

80 g of the quaternary ammonium compound (50 % solution in butanol) of Example 5 are mixed together with 288 g of MMA, 72 g of butyl methacrylate, 8.6 g of dibenzoyl peroxide and a mixture of 260 g of butanol and 300 g of - Solvesso 100. The mixture is copolymerised for 4 5 hours at 80C in a stream of nitrogen, with stirring. A 40 % solution having a viscosity of 8 Pa.s and an active ingredient content of 10 % is formed.

Examnle 10 75.5 g of the quaternary ammonium compound (50 % solution in butanol) of Example 4 are mixed together with 250 g of MRA, 52 g of styrene, 9.4 g of dibenzoyl peroxide and a mixture of 207.6 g of butanol and 283.2 g of Solvesso 100, and the mixture is de-aerated with nitrogen. The mixture is copolymerised for 4 - 5 hours at WC in a stream of nitrogen, with stirring. A 40 % solution having a viscosity of 1.2 Pa. s and an active ingredient content of 10 % is formed.

Example 11

75.5 g of the quaternary ammonium compound (50 % solution in butanol) of Example 5 are mixed together with 250 g of MMA, 52 g of styrene, 9.4 g of dibenzoyl peroxide and a mixture of 207.6 g of butanol and 283.2 g of Solvesso 100, and the mixture is de-aerated with nitrogen. The mixture is copolymerised for 4 - 5 hours at 80C in a stream of nitrogen, with stirring. A 40 % solution having a viscosity of 1.2 Pa. s and an active ingredient content of 10 % is formed.

Example 12

3-acrylamido-3-methyl-butanoic acid was prepared analogously to the method described by D.I. Hoke and R.D. Robins (J. Polym. Sci., 1972, 10, 3311-3315):

25.7 g of 3-acrylamido-3-methyl-butanoic acid and 16.2 g of benzyl alcohol are dissolved in 18 g of xylene and g of diethylene glycol dimethyl ether (diglyme) After the addition of 0.3 g of hydroquinone, 0.6 g of MBTO (mono-n-butyl tin oxide) and 0.5 ml of concentrated sulphuric acid as esterification catalysts, the water that forms as a result of the esterification is removed continuously for a period of 3 hours in vacuo at 80c using a water separator. When the esterification is complete, 30 g of MMA and 1.5 g of AIBN are added and then the mixture is copolymerised for 4 hours at 80C in a nitrogen atmosphere. A 40 % solution having a viscosity of 0.145 Pa.s is formed.

In order to determine the rates of hydrolysis of the binder systems according to the invention in alkaline medium, the changes in conductivity or pH with time were 15. measured. Direct measurement in sea-water (pH: 8.1 - 8.3) was not possible for reasons concerning techniques - of measurement (high intrinsic conductivity owing to the - salt content).

The measurements were carried out as follows:

20, In a three-necked flask - equipped with a stirrer, a pH electrode (supplied by WTW, type E50-1.5) and a conductivity electrode (supplied by WTW, type LTA 1, cell constant 0.996) - 300 ml of bidistilled and degassed water were adjusted to a pH of 12 by the addition of NaOH pellets. The temperature of the whole system was kept. constant at 25 0. 1C (Haake thermostat GH-D8). The measuring instruments used were a pH meter (supplied by WTW, type pH 192) or a conductivity-measuring device (supplied by WTW, type LF 530), which were connected to a four-channel recorder (supplied by Linseis, type 2046, 5 modules G 14.186 and G 7406).

The binder system in solution was applied to glass beads having a diameter of 3 mm and the solvent was removed with the aid of a vacuum pump. The originally weighted-in quantity of the polymeric binder system was so selected that an approximately 50 % excess of sodium hydroxide solution still remained after the reaction was complete.

In order to determine the rates of hydrolysis, the changes in conductivity or pH with time were then measured and recorded via the recorder. The measurement period was 24 hours.

The following Table clearly shows that the binder system according to the invention hydrolyses slowly in alkaline medium under the chosen conditions.

Table 1: Hydrolysis of binder systems Binder system Percentage of potential leaving groups hydrolysed within a period of 24 hours TBTM (monomer) 76.8 Standard copolymer (TBTM/MMA 1:2) 29.5 Polymer based on Example 4 (Ex.6) 14.9 TBM is tri-n-butyl tin methacrylate.

For the preparation of the antifouling paint systems, the polymeric binder system according to the invention is mixed with pigments and, optionally, with biocides in a suitable solvent.

The pigments are preferably pigments that are not readily soluble in water, such as, for example, copper oxide, copper thiocyanate, zinc oxide or zinc bis(dimethyldithiocarbamate), having additionally biocidal properties, or non-biocidal, insoluble pigments, such as titanium dioxide or iron oxide. The water-insoluble pigments used delay the hydrolytic dispersion of the antifouling paint system on account of their properties. 30 The concentrations of insoluble pigments used may be up to 40 % by weight of the total amount of pigment - but is preferably less than 20 % by weight. The ratio of the polymeric binder to the total pigment concentration is to be such that the pigment - 18 concentration by volume is over 25 % in the dry film preferably, the pigment concentration by volume is from 35 to 50 According to the invention, the following compounds may be used inter alia as co-biocides in an amount of the order of from 2 to 25 % by weight, preferably from 2 to 12 % by weight: dichlorophenyl- dimethylurea, 2-methylthio-tert.-butylamino-6-cyclopropylamino-s-triazine, zinc pyrithione, 2-(thiocyanomethyl)benzothiazole, 4,5-dichloro-2-N-octyl4-isothiazolin-3- one, 2,4,5,6-tetrachlorophthalonitrile, dichlofluanid.

Suitable solvents for those antifouling paints are, for example, aliphatic and aromatic hydrocarbons, such as, for example, toluene, xylene, heptane, and also alcohols, such as butanol, ketones, such as methyl isobutyl ketone, or esters, such as ethyl or butyl acetate, petroleum hydrocarbon fractions, such as, for example, ligroin, gasoline, or also water, dimethylfor- mamide, or mixtures of the mentioned solvents with one another (e.g. butanol/Solvesso 100 1:1).

The paint systems may also contain a plasticiser, for example tritolyl phosphate, diisooctyl phthalate, tributyl phosphate, polyvinyl methyl ether or a substi- tuted sulphonamide, such as, for example, N-ethyl-ptoluenesulphonamide, as well as other auxiliaries, dispersing agents, anti-settling agents, fillers, accelerators, inhibitors, colouring agents or siccatives, such as, for example, talc, Bentone, cobalt naphthenate, blue pigments.

The antifouling paint films are applied to the surface to be protected by means of the methods customarily employed, such as, for example, immersion, coating, spraying or sprinkling.

Antifouling paint 1 73.2 g of the copolymer of Example 1 (40 % solution in xylene), 5 g of copper(I) oxide, 13 g of zinc oxide, 11.1 g of Bentone 38 (gelling agent based on montmorillonite earth, Titangesellschaft, 6 % solution in xylene) and 10 g of xylene are ground intensively for one hour.

Antifouling Paint 2 73.2 g of the copolymer of Example 2 (40 % solution in xylene), 5 g of copper(I) oxide, 13 g of zinc oxide, 11.1 g of Bentone 38 (6 % solution in xylene) and 10 g of xylene are ground intensively for one hour.

Antifouling paint 3 73.2 g of the copolymer of Example 3 (40 % solution in xylene), 5 g of copper(I) oxide, 13 g of zinc oxide, 11.1 g of Bentone 38 (6 % solution in xylene) and 10 g of xylene are ground intensively for one hour.

Antifouling paint 4 73.2 g of the copolymer of Example 2 (40 % solution in butanol/Solvesso 100 1:1), 20 g of titanium dioxide RN 57 and 10 g of butanol/So Ives so 100 1:1 are ground inten5 sively for one hour.

Antifouling paint 5 73.2 g of the quaternary ammonium compound of Example 6 (40 % solution in butanol/Solvesso 100 1:1), 5 g of copper(I) oxide, 13 g of zinc oxide, 11.1 g of Bentone 38 (gelling agent based on montmorillonite earth, Titangesellschaft) (6 % solution in xylene) and 10 g of butanol/Solvesso 100 1:1 are ground intensively for one hour.

Antifouling paint 6 73.2 g of the quaternary ammonium compound of Example 7 (40 % solution in butanol/Solvesso 100 1:1), 20 g of titanium dioxide RN 57 (Bayer) and 10 g of butanol/Solvesso 100 1:1 are ground intensively for one hour.

Antifouling paint 7 73.2 g of the quaternary ammonium compound of Example 8 (40 % solution in butanol/Solvesso 100 1:1), 5 g of copper(I) oxide, 13 g of zinc oxide, 11. 1 g of Bentone 38 (6 % solution in xylene) and 10 g of butanol/Solvesso 100 1:1 are ground intensively for one hour.

Antifouling lpaint 8 73.2 g of the copolymer of Example 9 (40 % solution in butanol/Solvesso 100 1:1), 20 g of titanium dioxide RN 57 and 10 g of butanol/Solvesso 100 1:1 are ground inten5 sively for one hour.

Antifouling paint 9 73.2 g of the quaternary ammonium compound of Example 10 (40 % solution in butanol/Solvesso 100 1:1), 5 g of copper(I) oxide, 13 g of zinc oxide, 11.1 g of Bentone (6 % solution in xylene) and 10 g of butanol/Solvesso 100 1:1 are ground intensively for one hour.

Antifouling paint 10 73.2 g of the copolymer of Example 12 (40 % solution in xylene), 5 g of copper(I) oxide, 13 g of zinc oxide, 11.1 g of Bentone 38 (6 % solution in xylene) and 10 g of xylene are ground intensively for one hour.

When the substituent R4 is a quaternary ammonium compound of the type CR5R07X-, the binder system according to the invention exhibits biocidal activity against marine organisms. The substituents R5, R6, R7 here correspond to branched or unbranched Cl-C18-alkyl groups or substituted benzyl groups of the type -CH2C04R10 wherein R10 = H, Cl, Br, I, N02, CN, CH3.

The biocidal effect of the binder system according to the invention with the substituents -CR5R6R7X_ can be strengthened or broadened by the use of poorly watersoluble pigments, such as copper oxide, copper thiocyanate or zinc thiocarbamates, or additionally by other biocides, such as, for example, 2,4,5,6-tetrachloroisophthalonitrile, 2methylthio-4-tert.-butylamino-6cyclopropylamino-s-triazine, 2thiocyanomethyl-thiobenzothiazole, 3-(3,4-dichlorophenyl)-1,1dimethylurea, 3-iodo-2-propynyl butylcarbanate, dibromosuccinates, dichlofluanid, diphenylamine, isothiazolones, manganese ethylenebisdithiocarbamate, organometal compounds, tetramethylthiuram disulphide, zinc bis(dimethyldithiocarbamate), zinc pyrithione.

The activity of the binder systems according to the invention against marine organisms was determined by means of ageing tests both in the Mediterranean and in the North Sea. For that purpose, polyvinyl chloride test plates (10 x 15 x 0.4 cm) were provided with antifouling paints. 20 After degreasing, the PVC plates were painted with two coats of the antifouling composition and dried for 48 hours. The thickness of the dry film was from 80 to 120 pm. The PVC plates were then clamped in a plastics frame and aged for a period of 12 months approximately 0.3 0.5 m beneath the water surface. Untreated PVC plates were used as reference sample.

The following Table clearly shows that the binder systems according to the invention, in which R4 is a quaternary ammonium compound of the type N+RSR6R7X-, exhibit biocidal activity against animal and vegetable 5 fouling during the observation period.

The test plates without the compounds according to the invention exhibited considerable fouling by algae, Balanidae and shells.

10- Table 2

3 months 6 months 12 months Antifouling paint 5 0 1 2 Antifouling paint 6 0 3 5 Antifouling paint 7 0 2 3 Antifouling paint 8 0 2 5 Antifouling paint 9 0 1 3 Comparative examples Untreated PVC plate 10 10 10 Antifouling paint 1 0 4 8 0 = no fouling = 50 % fouling = complete fouling

Claims

1. A hydrolysable polymeric resin of the general formula Rt 1 - [-CH2 -B-] - 1 6=0 1 (2) N-H 1 (R2 -L-Ki)p in which R1 is H or CH3 R2 is selected from H and Cl-C4-alkyl groups R3 is selected from H and Cl-C4-alkyl groups p is from 0 - 4 R4 is either (CH2) n (Y) m (CH2) 0 N+R5R6R7 X- wherein n is from 0 - 6 m is 0 or 1 Y is selected from substituted phenyl rings of the general formula C6H2R8R9 wherein R8, R9 may be the same or different and each is selected from H, CH3, Br, Cl, N02, W 0 is from 0 - 2 R5, R6, R7, which may be the same or different, are each selected from H, linear or branched Cl-C18-alkyl groups, and substituted benzyl groups of the type -CH2-CO4R10 Wherein Rio= H, Cl, Br, I, N02, CN, CH3 X is selected f rom Br, Cl, I or (CH2)qCOOR11 Wherein R,, is selected from H, Cl-C6-alkyl groups, and unsubstituted and monosubstituted benzyl and phenyl groups with one or more substituents selected from H, Cl, Br, I, 10 N02, CN and CH3 q is from 0 - 2 and B is a constituent unit derived from a previously ethylenically unsaturated monomer, said unit being present in a percentage of > 80 % by weight, based on the total polymer.

2. A hydrolysable prepolymeric resin of the general formula (2) in which R1 is CH3, R2 and R3 are each H and in which in R4 the radicals R5 and R6 are each CH3 and R7 is a benzyl radical, with n = 2, p = 1, m = 0, o = 0.

3. A hydrolysable polymeric resin according to claim 1, in which from 2 to 5 % by weight of the constituent units B of the general formula (2) are units derived from acrylic acid.

4. A polymeric binder system for an antifouling paint for protecting maritime surfaces, which system consists essentially of a) a polymeric resin of the general formula (2) X RL i - [-CH? C -B-] 1 6=0 1 N-H 1 K2 -L - K3 1 (2) R4 in which R1 is H or CH3 R2 is selected from H and Cl-C4-alkyl groups 5 R3 is selected from H and Cl-C4-alkyl groups p is from o - 4 R4 is either (CH2)n (y)m (CH2)o N+R5R6R7 X- wherein n is from 0 - 6 m is 0 or 1 Y is selected from substituted phenyl rings of the general formula C6H2R8R9 wherein R8, R9 may be the same or different and each is selected from H, CH3, Br, Cl, N02, CN 0 is from 0 - 2 R5, R6, R7, which may be the same or different, are each selected from H, linear or branched Cl-C18-alkyl groups, and substituted benzyl groups of the type -CH2-CO4R10 Wherein R10 = H, Cl, Br, I, N02, CN, CH3 X is selected from Br, Cl, I or (CH2)qCOOR11 wherein R,, is selected from H, Cl-C6-alkyl groups, and unsubstituted and monosubstituted benzyl 5 and phenyl groups with one or more substituents selected from H, Cl, Br, I, N02, W and CH3 q is from 0 2 and B is a constituent unit derived from a previously ethylenically unsaturated monomer, said unit being present in a percentage of > 80 % by weight, based on the total polymer, and, optionally, b) one or more co-biocides and, optionally, c) one or more substances selected from customary auxiliaries, additives, pigments, plasticisers, levelling agents.

5. A polymeric binder system according to claim 4, in which the polymeric resin according to a) is used in an amount of from 15 to 40 % by weight, based on the total system.

6. A polymeric binder systems according to claim 3 or claim 4, in which in there are used as co-biocides dichlorophenyl-dimethylurea, 2methylthio-tert.-butyl- amino-6-cyclopropylamino-s-triazine, zinc pyrithione, 2- (thiocyanomethyl)benzothiazole, 4,5-dichloro-2-N-octyl4-isothiazolin-3- one, 2,4,5,6-tetrachlorophthalonitrile, - 28 dichlofluanid.

7. An antifouling paint comprising a hydrolysable polymeric resin which is the copolymerisation product of (i) a compound of the f ormula R1 0 1 11 CH2 = C-C-NH-R in which the group R is a group comprising a quaternary ammonium or an ester group and the group R1 is H or CH3; and (ii) an ethylenically unsaturated monomer, the proportion by weight in the copolymerisation product constituted by units derived from the ethylenically unsaturated monomer being not less than 80% by weight based on the total weight of the copolymerisation product.

8. A paint as claimed in claim 7, in which the group R is a hydrocarbyl moiety to which a quaternary ammonium group is attached, the hydrocarbyl group optionally comprising one or more further substituents.

9. A paint as claimed in claim 8, in which the hydrocarbyl moiety is an alkylene chain having up to nine carbon atoms in the chain, that may optionally be substituted by up to two Cl-C4-alkyl groups.

10. A paint as claimed in claim 8 or claim 9, in which the hydrocarbyl moiety is an alkylene chain having up to nine carbon atoms in the chain which may be interrupted by, or have at a terminal position, a phenyl group which may optionally have one or more substituents selected from the group consisting of CH3, Br, Cl, N02 and W.

11. A paint as claimed in claim 7, in which the group R is an alkylene chain having a terminal carboxyl ester group, the alkylene chain having up to three carbon atoms in the chain and optionally being substituted by one or more Cl-C4-alkyl groups.

12. An antifouling paint as claimed in any of claims 7 to 11, in which said resin comprises units of the general formula (2) as def ined in claim 1.

13. An antifouling paint comprising a hydrolysable polymeric resin according to any of claims 1 to 3 or a polymeric binder system according to any one of claims 4 to 6.

14. An antifouling paint comprising a copolymer, said copolymer being substantially as described in any of Examples 6 to 12.

15. An antifouling paint substantially as described herein as Antifouling paint 5, Antifouling paint 6, Antifouling paint 7, Antifouling paint 8, Antifouling paint 9 or Antifouling paint 10.