EP3618631A1 - Alkyd-encapsulated biocide - Google Patents

Abstract

The present invention relates to an emulsion of a biocide-comprising alkyd in an aqueous solution wherein the aqueous solution comprises between 0.1 and 10 wt% of surfactant, a process to prepare such an emulsion and to a coating composition comprising such an emulsion.

Description

ALKYD-ENCAPSULATED BIOCIDE

Field of the Invention

[0001 ] The present invention relates to an emulsion of an alkyd in an aqueous solution wherein the alkyd comprises a biocide, a process to prepare such an emulsion and to a coating composition comprising such an emulsion.

Background of the Invention

[0002] Paints such as architectural paints containing insecticides used to coat walls, floors and ceilings inside buildings are known. Such insecticidal paints usually kill insects by contact. Many of the known insecticidal paints are solvent borne, that is to say, the majority, if not all of the carrier liquid is organic solvent. This is largely because insecticides are large organic molecules that do not readily dissolve in aqueous paints, particularly at the low VOC (volatile organic content) level demanded by legislation and consumers throughout the world. [0003] Paints, comprising an insecticide (i.e. an insecticidal paint) can be made by adding the desired amount of insecticide to the final paint composition.

[0004] Ready to use insecticidal paints are known. Such paints are disclosed in WO2006/070183 and comprise an insecticide encapsulated by thin layers of cross-linked polymer. The capsules are formed from highly cross-linked polyurea or cross-linked aminoplast resins and require complex and expensive processes to produce. Such cross-linked polymers do not film form at ambient temperatures.

[0005] In WO201364441 is disclosed that certain insecticides remain active in the dried paint film for only a short time, sometimes only a few days, resulting in dried paint films which contain no active insecticide, or at least so little that it is less than the minimum effective amount necessary to kill all or even some of the insects. Insecticides which are susceptible to leaving the dried film in this way are volatile. Interior architectural paint is normally expected to last many months and possibly a year or more. Naturally, consumers expect that the insecticidal activity of an insecticidal paint will also last a similar length of time. A way of making low VOC aqueous insecticidal architectural paints, comprising volatile insecticides is disclosed in WO201364441 . It discloses a simple method without the need of insecticide encapsulated in cross-linked polymer. [0006] Several encapsulation methods are known in the art e.g. matrix encapsulation wherein the active compound is dispersed in the encapsulation material (beads, microparticles, microspheres); or core / shell encapsulation wherein the active compound is confined as one core by one shell or more (multi-shell). Core / shell encapsulation is sometimes also referred to as microencapsulation. A microcapsule is a small sphere with a uniform wall around it. The material inside the microcapsule is referred to as the core, internal phase, or fill, whereas the wall is sometimes called a shell, coating, or membrane.

[0007] EP2851401 discloses a biocide composition for controlling invasive species and pests, coating products thereof and use thereof. It discloses the microencapsulation of active substances with a binder in a polymer and mineral casing. The microencapsulation of active substance e.g. insecticide, is obtained using polymerization of binder in a polymer and mineral casing creating a core- shell structure around the active substance. The encapsulation requires the polymerization of at least one monomer in the interphase of two immiscible substances, giving rise to a membrane that constitutes the wall of the microcapsule (core/shell encapsulation).

[0008] In matrix encapsulation the active ingredient is dispersed uniformly throughout a continuous material (matrix) and the main release profile is sustained release where the active is slowly released over time. For this type of encapsulation to be effective several conditions need to be fulfilled. First, the active needs to have a very high partition coefficient (solubility) in the material. Secondly the matrix of choice needs to be water insoluble and inert to other formulation components as well as the active. The matrix should have a high glass transition temperature or reasonable crosslinking to allow for slow diffusion of the active out of the matrix.

[0009] EP201214 discloses polymeric microparticles having bound therewith a pesticide in which active substances are bound to the outer surface of microparticles.

[0010] Also combinations of encapsulation techniques are known such as for example from EP2545775 which discloses a granular core material with a first coating layer of wax comprising a biologically active ingredient incorporated therein and a second coating layer including a polymeric composition. [001 1 ] Inesfly ® products use the micro-encapsulation technology, which is the key element that gives Inesfly products their special characteristics. The formation of the Inesfly Technology is a chemical process which produces microcapsules in suspension. These microcapsules are as a core-shell species whereby there is a core comprising the active, and a shell, wall or structure that surrounds the former, without active. These microcapsules include conventional biocides at very low doses and insect growth regulators. Gradual and controlled release of the microencapsulated active ingredients is a direct result of the polymeric covering (www.inesflyafrica.com).

[0012] The product known as Painticide, released in collaboration with the Institute for Medical Research (IMR), is an emulsion paint formulation impregnated with a pyrethroid (deltamethrin) that allows the slow release of the insecticide to the wall surface (http://www.imr.qov.my/). It discloses a "drop in" of deltamethrin into the paint formulation after which the biocide is trapped in the resulting paint formulation. [0013] Many insecticides including many of the class of pyrethrins, comprise one or more chiral centers and often the insecticidal activity of the insecticide differs between different enantiomers, diastereomers or epimers. A problem with existing coating and/or paint compositions comprising insecticides is that due to the alkaline conditions such as in wet paint, racemization of one or more of the chiral centers may occur in the wet paint reducing the effective active concentration of the insecticide. This is especially the case with waterborne coatings compositions. To maintain a minimum level of active concentration of insecticide, a doubling of the concentration of insecticide is required for each chiral atom where racemization may occur during storage. That would increase the costs of the coating composition and may also influence coating quality. Additionally, there is a trend towards reduction of authorized active substances or reduction of levels of authorized active substances.

[0014] There is thus need in the art for a waterborne coating composition comprising an insecticide wherein a chiral insecticide does not racemize.

Summary of the Invention

[0015] It has now been found that racemization of an insecticide in a waterborne paint (i.e. coating composition) can be reduced using a matrix-type encapsulation of the insecticide in an alkyd which reduces the racemization of an optically active insecticide. The alkyd-encapsulated insecticide may be added to a coating composition and still maintain its protective environment for the insecticide in the coating composition. The alkyd encapsulation prevents the insecticide from racemization or at least reduces the racemization speed. In addition, the alkyd encapsulation does not prevent migration of the insecticide to the surface of the (dried) coating layer and hence allows for a prolonged activity of the insecticide. It is understood that this type of alkyd encapsulation can also be applied more generally to optically active biocides.

[0016] Accordingly, the present invention provides an emulsion of an alkyd in an aqueous solution wherein the alkyd comprises a biocide and the aqueous solution comprises between 0.1 and 10 wt% of surfactant.

[0017] The invention further provides a process to prepare such an emulsion and a coating composition comprising such an emulsion.

Definitions [0018] The term "alkyd" refers herein to polyester derived from polyols such as pentaerytritol, trimethylolpropane of propeneglycol and a dicarboxylic acid such as phthalic acid or maleic acid or carboxylic anhydride such as phthalic acid anhydride or maleic acid anhydride. Alkyds may further comprise triglycerides derived from polyunsaturated fatty acids (often derived from plant and vegetable oils, e.g. linseed oil, soybean oil, sunflower oil, or safflower oil). A typical alkyd resin is prepared by heating for example linseed oil, phthalic acid anhydride and glycerol to obtain a fatty-acid containing polyester. Alkyds can be used in paints or coating compositions. Different levels of oil in the paint provide different paint characteristics. Alkyds and alkyd-based paints can be diluted with solvents to allow for an easier handling. Further important components of alkyd paint are pigments and extenders. The pigment is the substance that gives the paint color. Pigments are derived from natural or synthetic materials that have been ground into fine powders. Extenders are inert pigments used to extend or increase the bulk of paint. Extenders are also used to adjust the consistency of paint and to let down colored pigments of great tinting strength. The last important category of components of alkyd paint comprises the additives e.g. to accelerate paint drying.

[0019] Alkyds can be classified based on a wide range of properties such as oil length and acid value being, see for example Coatings Technology Handbook, Second Edition edited by D. Satas, Arthur A. Tracton pages 435-437, which is included herein by reference.

[0020] "Oil length" is defined as weight % of oil calculated on the theoretical non-volatile content of the final alkyd when condensed to the midpoint of the acid value specification: very long oil: 75% and over; long oil: between 60 and 75%; medium oil: between 45 and 60%; short oil: up to 45%.

[0021 ] "Acid value" is defined as the number of milligrams of potassium hydroxide required to neutralize one gram of the polymer under the conditions specified below (lUPAC definition). It is determined using a standard potassium hydroxide solution (0.1 N) in methanol and a one per cent of phenolphthalein in ethanol (95 per cent) as indicator. An ethanol— toluene mixture is prepared by mixing equal volumes of ethanol (95 per cent) and toluene and neutralized with a methanolic potassium hydroxide solution (0.1 N) in the presence of phenolphthalein as indicator. 1 -2 g of the sample is dissolved in 50 ml of the ethanol— toluene mixture. The solution is titrated with methanolic potassium hydroxide solution in the presence of pbenolphtbalein as indicator. The acid value is calculated as follows:

Acid value = 56.1 aN/p.

Wherein a = ml methanolic potassium hydroxide solution

N = normality of the methanolic potassium hydroxide solution

p = weight of the sample in g (see Recommended methods for the analysis of alkyd resins by lUPAC: https://www.iupac.org/ under subpage publications/pac-2007/1973/pdf/3302x041 1 .pdf.)

[0022] "Enantiomer ratio" is defined as the amount of the first enantiomer (E1 ) divided by the amount of the second enantiomer (E2), i.e. E1/E2.

[0023] "Enantiomer fraction" is defined as the amount of the first enantiomer divided by the total amount of the first and second enantiomer, i.e. E1 / (E1 + E2).

[0024] "Enantiomer excess" is defined as the absolute value of the difference in the amount of the first enantiomer and second enantiomer, i.e. |E1 - E2| where E1 +E2 = 1 (or 100%).

[0025] "Surfactant" refers to compounds that lower the surface tension (or interfacial tension) between two liquids Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants. Surfactants are usually organic compounds that are amphiphilic, meaning they contain both hydrophobic groups (their tails) and hydrophilic groups (their heads). Therefore, a surfactant contains both a water-insoluble (or oil-soluble) component and a water-soluble component. Surfactants will diffuse in water and adsorb at interfaces between air and water or at the interface between oil and water, in the case where water is mixed with oil. The water-insoluble hydrophobic group may extend out of the bulk water phase, into the air or into the oil phase, while the water-soluble head group remains in the water phase. Most commonly, surfactants are classified according to polar head group. A non-ionic surfactant has no charged groups in its head. The head of an ionic surfactant carries a net positive, or negative charge. If the charge is negative, the surfactant is more specifically called anionic; if the charge is positive, it is called cationic. If a surfactant contains a head with two oppositely charged groups, it is termed zwitterionic. Anionic surfactants contain anionic functional groups at their head, such as sulfate, sulfonate, phosphate, and carboxylates and are well-known in the art. Non-ionic surfactants include many long chain alcohols which exhibit some surfactant properties e.g. fatty alcohols, cetyl alcohol (hexadecane-1 -ol or palmityl alcohol), stearyl alcohol, and oleyl alcohol. Other examples of non-ionic surfactants include polyethylene glycol alkyl ethers (e.g. octaethylene glycol monododecyl ether, pentaethylene glycol monododecyl ether), polypropylene glycol alkyl ethers, glucoside alkyl ethers (e.g. decyl glucoside, lauryl glucoside, octyl glucoside), polyethylene glycol octylphenyl ethers (e.g. triton X-100), polyethylene glycol alkylphenyl ethers (e.g. nonoxynol-9), glycerol alkyl esters (e.g. glyceryl laurate), polyoxyethylene glycol sorbitan alkyl esters (e.g. polysorbate), sorbitan alkyl esters, cocamide MEA, cocamide DEA, dodecyldimethylamine oxide, block copolymers of polyethylene glycol and polypropylene glycol, polyethoxylated tallow amine (POEA), or mixtures thereof.

[0026] Median particle size d(0.5) of the emulsion refers to the median diameter or the medium value of the particle size distribution in the emulsion. It is the value of the particle diameter at 50% in the cumulative distribution. For example, if D(0.5)= 9.1 μιη, then 50% of the particles in the sample are larger than 9.1 μιη, and 50% smaller than 9.1 μιη. The median particle size can for example be measured using a Mastersizer 2000 instrument as described elsewhere herein. [0027] A water-borne coating composition or waterborne paint is herein defined as a coating / paint composition wherein the amount of non-aqueous solvent is less than 15 wt%, preferably less than 10 wt%, more preferably less than 5 wt%, such as less than 4, 3, 2, or even less than 1 wt%. [0028] A coating composition can be applied to the surface of an object, usually referred to as the substrate. The purpose of applying the coating may be decorative, functional, or both. The coating itself may be an all-over coating, completely covering the substrate, or it may only cover parts of the substrate. Paints and lacquers are coatings that mostly have dual uses of protecting the substrate and being decorative, although some artist's paints are only for decoration, and the paint on large industrial pipes is presumably only for the function of preventing corrosion. After application of the coating composition to a substrate the coating composition dries / cures to become a dried coating film or covering of the substrate. Drying and curing of a coating occurs e.g. by evaporation of solvents and polymerization reactions between different components in the coating composition.

[0029] Weight percentages (wt%) of an ingredient in a composition are expressed as the weight percentage of the specific ingredient compared to the weight of the total composition. FIGURES

[0030] Figure 1 the median particle size d(0.5) of emulsions prepared from the eight (8) different alkyds as listed in the examples containing deltamethrin at 0.5 and 1 .0 wt% (black and grey column, respectively). [0031 ] Figure 2 Deltamethrin active isomer (%), (as a measure of stability towards racemization) in a water-based (waterborne) coating composition is shown when added as standard drop-in in white water-based wall paint in the PVC range of 20 - 80 as a function of pH. [0032] Figure 3 Deltamethrin stability when encapsulated in very long oil alkyd emulsion as compared standard drop in (DMN-SC) as a function of pH. Figure 3A for pH=8, Figure 3B for pH=9 and Figure 3C for pH=10.

[0033] Figure 4 Deltamethrin stability when encapsulated in long oil alkyd emulsion as compared standard drop in (DMN-SC) as a function of pH. Figure 4A for pH=8, Figure 4B for pH=9 and Figure 4C for pH=10.

[0034] Figure 5 Deltamethrin stability when encapsulated in short and medium oil alkyd emulsion as compared standard drop in (DMN-SC) as a function of pH. Figure 5A for pH=8, Figure 5B for pH=9 and Figure 5C for pH=1 [0035] Figure 6 Bio efficacy for eight variants of encapsulation of deltamethrin in alkyd number 6 compared to standard drop-in.

[0036] Figure 7 Bio efficacy of deltamethrin encapsulated in very long oil chain alkyd compared to the freshly prepared drop-in at 0.1 wt% active in a white waterbased wall paint in the PVC range of 20 - 80. Detailed Description of the Invention

[0037] The invention relates to an emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide and the aqueous solution comprises between 0.1 and 10 wt% of surfactant. It has surprisingly been found that the racemization rate of the biocide can be reduced by dissolving it in the alkyd phase of such an emulsion. As a result, the biocide remains active for a longer period of time and a paint formulation comprising the emulsion can be prepared and stored for a longer period compared to drop in compositions.

[0038] The alkyd oil length may vary in the emulsion of the invention. In one aspect, the alkyd oil length is higher than 60%, preferably wherein the alkyd oil length is higher than 75%. Also mixtures of alkyds with different oil lengths may be used. [0039] In one aspect of the invention the acid value of the alkyd is between 0 and 20. In another aspect the acid value is between 0 and 15. In still another aspect the acid value is between 2 and 15. In yet another aspect it is between 2 and 10. In one aspect it is below 2, or in another aspect it is between 10 and 15. [0040] The emulsion obtained according to the invention may comprise different amounts of surfactant concentration and/or type of surfactant. In one aspect of the invention, the surfactant is selected from one or more members of the group consisting of non-ionic surfactants and ionic surfactants; preferably the surfactant is an non-ionic surfactant. In one embodiment the non-ionic surfactant is polyvinylalcohol of medium levels of hydrolysis (e.g. 88%) and medium molecular weight (e.g. 31000 Da). Also the amount of surfactant may be varied to steer emulsion characteristics. In one aspect the surfactant concentration in the emulsion obtained in the method according to the invention to encapsulated a biocide in an alkyd is between 0.1 and 10 %wt , or in another embodiment between 1 and 9%wt or between 2 and 8 %wt, or even between 3 and 7 %wt. In another embodiment the amount of non-ionic surfactant in the emulsion obtained in the method according to the invention to encapsulated a biocide in an alkyd is between 0.1 and 10 %wt , or in another embodiment between 1 and 9%wt or between 2 and 8 %wt, or even between 3 and 7 %wt. [0041 ] Also the amount of non-volatiles may vary in the emulsion of the invention. In one aspect the emulsion of an alkyd in an aqueous solution of the current invention comprises between 20 and 60 % non-volatiles, preferably between 35 and 50% non-volatiles. In another embodiment it is between 30 and 55 %wt. In still another embodiment it is between 40 and 50 %wt. In yet another embodiment it is between 38 and 42 %wt.

[0042] A problem with existing coating and/or paint compositions comprising insecticides is that due to the alkaline conditions such as in wet paint, racemization of one or more of the chiral centers may occur in the wet paint reducing the effective active concentration of the insecticide. As is illustrated in the examples the encapsulation of a biocide in an alkyd emulsified in an aqueous solution according to the invention prevents or at least reduces racemization of the alkyd-encapsulated biocide at alkaline pH values. Racemization of biocides, e.g. insecticides such as deltamethrin, is known to occur under basic conditions. Under neutral conditions, the racemization rate is generally lower than under basic conditions. Hence in one aspect the invention relates to an emulsion of an alkyd in an aqueous solution as herein described wherein the pH of the emulsion is between 7 and 1 1 , preferably between 8 and 10, or wherein the pH of the emulsion is between 8 and 9. In yet another embodiment it is between 7.5 and 10.5. Likewise the pH of a coating composition comprising an emulsion of an alkyd in an aqueous solution as herein described is in one aspect between 7 and 1 1 , in another embodiment between 7.5 and 10.5, or even between 8 and 10, in yet another embodiment it is between 8 and 9.

[0043] The amount of biocide in the emulsion of an alkyd in an aqueous solution according to the current invention depends upon the type of biocide used. It is understood that biocides may have different minimum concentrations in order to be effective. In another aspect the invention relates to an emulsion of an alkyd in an aqueous solution of the current invention wherein the amount of biocide in the emulsion is less than 10 %wt, e.g. less than 9, 8, 7, 6, 5, 4, 3 %wt or even less than 2 %wt or less than 1 %wt. In another aspect it is between 0.001 and 10 wt% calculated from the weight of the emulsion. In still another aspect it is between 0.001 and 6 wt%, or between 0.01 and 6 wt%, e.g between 0.01 and 5wt%, between 0.1 and 6wt%, or in yet another embodiment between 1 and 6 wt%, or in still another embodiment between 0.01 and 2 wt%, or even between 0.1 and 1 wt%. In one embodiment it is between 2 and 5 wt%.

[0044] The emulsion of an alkyd in an aqueous solution according to the current invention can be stored for several days such as at least 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, or even at least 100 days. The emulsion may be stored at room temperature. The median particle size d(0.5) of the emulsion does not affect the stability of the biocide, hence in one aspect, there are no restriction on the median particle size d(0.5) of the emulsion. In one aspect the median particle size d(0.5) of the emulsion is below 1 .0 micron. In another aspect the median particle size d(0.5) of the emulsion is between 0.5 and 30 microns or in still another aspect between 1 and 1 1 microns. In yet another aspect the median particle size d(0.5) of the emulsion is between 5 and 10 microns. In a further aspect, the median particle size d(0.5) of the emulsion remains stable during storage. It is understood that larger particles in an emulsion may settle during storage, they may be redispersed using methods known in the art such as using low shear mixing. [0045] In another aspect, the invention relates to an emulsion of an alkyd in an aqueous solution of the current invention wherein the biocide is an insecticide. In one embodiment, the insecticide is a pyrethroid or pyrethrin. The class of insecticides called pyrethroids comprises insecticides such as Allethrin, Bifenthrin, Cyfluthrin, Cypermethrin, Cyphenothrin, Deltamethrin, Esfenvalerate, Etofenprox, Fenpropathrin, Fenvalerate, Flucythrinate, Flumethrin, Imiprothrin, lambda-Cyhalothrin, Metofluthrin, Permethrin, Prallethrin, Resmethrin, Silafluofen, Sumithrin, tau-Fluvalinate, Tefluthrin, Tetramethrin, Tralomethrin, and Transfluthrin.

[0046] Preferably the insecticide is a pyrethroid; more preferably the insecticide is selected from the group consisting of permethrin, deltamethrin and cypermethrin, or combinations thereof; even more preferably the insecticide is deltamethrin. Deltamethrin is a well-known insecticide that can be used in this invention because it has an chiral center that is known to racemize under alkaline conditions. Deltamethrin has a fast action against invasive species, a relative short contact period between the species and deltamethrin is sufficient to be effective, e.g. an insect landing on a substrate coated with a coating composition according to the invention can be long enough for deltamethrin to be effective against the insect. [0047] In still another aspect, the invention relates to a process for preparing the emulsion of an alkyd in an aqueous solution of the current invention, comprising the steps of: providing an aqueous solution of a surfactant comprising between

0.1 and 10 wt% of surfactant,

providing an alkyd optionally dissolved in a solvent, providing a biocide,

dissolve the biocide in the alkyd,

v. emulsifying the biocide dissolved in the alkyd of step iv in the aqueous solution of step I,

vi. optionally removing the solvent of step ii,

vii. optionally adjusting the pH of the emulsion to a value between 7 and 1 1 , preferably between 8 and 10, or to a value between 8 and 9.

[0048] It is understood that steps ii, iii, and iv, may be replaced by an alternative step of providing a biocide dissolved in an alkyd. This is particularly interesting when the solution of the desired biocide in the desired alkyd can be obtained. In one embodiment the invention relates to the process as described above comprising the alternative step instead of steps ii, iii, and iv. In another aspect, the invention relates to an emulsion of an alkyd in an aqueous solution obtained in this process.

[0049] Emulsifying an alkyd in an aqueous solution can be done by adding the aqueous solution into the alkyd, or by adding the alkyd into the aqueous solution. In one embodiment of the process to prepare the emulsion according to the current invention, in step v the emulsion is prepared by adding the aqueous solution into the alkyd, or by adding the alkyd into the aqueous solution; preferably by adding the alkyd into the aqueous solution as this preparation method allows for a wider range of emulsion properties to be achieved (e.g. particle size). Variation of the process parameters such as mixing time, mixing speed, rate of addition, neutralization rate, ratio between surfactants used, process temperature may influence the characteristics of the emulsion obtained.

[0050] Based on simple modelling using Fick's diffusion laws, it is assumed that the leaching rate of the active (e.g. biocide or insecticide) out of the alkyd encapsulation is controlled by the type of matrix (i.e. type of alkyd) and the particle size (controlled by process parameters). To decrease the amount of active leached a larger particle size is desirable although this could also impact on storage stability of the emulsion. A decrease in diffusion coefficient which may be influence by the type of alkyd, also leads to a decrease on the amount of active leached.

[0051 ] In general longer alkyds have high solids content and a low solvent content, such solvent being of an organic nature, in other words being classified as "volatile organic solvent" (VOC) which needs to be removed from the emulsion obtained in the process according to the invention (step vi). When using very long alkyd oil lengths, the optional step vi "remove solvent from step ii" may be redundant, especially when the liquid content of the alkyd is low such as less than 10 wt %, preferably less than 5 wt%, or less than 4, 3, or even less than 2 wt%, the wt% being calculated on the total weight of the alkyd.

[0052] The emulsion of the instant invention can be added to a coating composition. It has surprisingly been found that the reduced racemization of the biocide as found in the emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide is maintained when such an emulsion is added to a coating composition. So in a further aspect, the invention relates to a coating composition comprising the emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide as herein defined. In one embodiment, the racemization of the biocide in such a coating composition is less than 50% when stored at 54°C for 3 weeks. In another embodiment, in such a coating composition, the relative amount of active enantiomer of the biocide after 3 weeks of storage at 54 °C is at least 2% higher than the relative amount of active enantiomer of the insecticide in an identical coating composition (except for alkyd-encapsulated biocide) comprising the same amount of biocide via "drop-in" after 3 weeks of storage at 54 °C. In still a further aspect, the amount of biocide in such a coating composition is between 0.0001 and 5 wt%, or the amount of insecticide in such a coating composition is between 0.0001 and 5 wt%.

[0053] In yet another aspect, the invention relates to a coating composition comprising the emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide as herein defined, wherein the pH of the coating composition is between 7 and 1 1 , preferably between 8 and 10, or wherein the pH of the coating composition is between 8 and 9. The coating composition can be a latex or another type of paint. It is water borne. In another aspect, the racemization of the biocide in the coating composition comprising the emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide according to the invention, is less than 50% when stored at 54°C for 3 weeks. In other words, after 3 weeks of storage at 54°C, more than 50% of the biocide has the same configuration (is the same enantiomer/ stereoisomer) as at the beginning of the storage period. In another embodiment, the racemization of the biocide is less than 45%, e.g. less than 40%, 35%, 30%, 25%, 20%, 15%, 10% or even less than 5% when stored at 54°C for 3 weeks. [0054] In still another aspect the enantiomer excess of active enantiomer of the biocide in a coating composition comprising the alkyd encapsulated biocide according to the invention, after 3 weeks of storage at 54 °C, is at least 2% higher e.g. at least 3%, 4%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80% or even at least 90% higher than the enantiomer excess of the active enantiomer in an identical coating composition comprising the same amount of biocide via "drop in". In other words, starting with two containers comprising the same coating composition, the biocide (with a known enantiomer excess) is added to the first one in form of an alkyd-encapsulated biocide as herein described, the same amount of biocide with the same enantiomer excess is added to the second container via "drop in". So the amount of biocide (wt%) in both containers is the same. Both containers are stored under the same conditions (closed container, mixing the alkyd through the coating composition, storage at 54°C for 3 weeks).

[0055] It is understood that "drop in" of a biocide in a coating composition means that the biocide is added to the coating composition in a pure form, i.e. the pure biocide (or a solution thereof) is added drop wise to the coating composition to the desired concentration.

[0056] Depending on the biocide, different final concentrations of the biocide in the coating composition may be desirable. So in another aspect of the invention the relative amount of biocide in a coating composition comprising the alkyd-encapsulated biocide according to the invention is between 0.001 and 10 wt% of the coating composition. In another embodiment it is between 0.01 and 5 wt% of the coating composition. In one embodiment it is between 0.01 and 3 wt%. In yet another embodiment it is between 0.01 and 2.5 wt%. In still another embodiment it is between 0.05 and 5 wt% or between 0.1 and 5 wt%. In yet another aspect of the invention the relative amount of insecticide in a coating composition comprising the alkyd-encapsulated insecticide according to the invention is between 0.001 and 5 wt% of the coating composition. In one embodiment it is between 0.01 and 3 wt%. In yet another embodiment it is between 0.01 and 2.5 wt%. In still another embodiment it is between 0.05 and 2.5 wt%. Preferably the amount of biocide is less than 2.5 wt%, e.g. 2.0, 1 .5 or 1 .0 wt%. Accordingly, in one embodiment the amount of biocide in the coating composition of the invention is between 0.001 and 1 .0 wt%. In another embodiment the amount of insecticide in the coating composition of the invention is between 0.001 and 1 .0 wt%. In still another embodiment the amount of deltamethrin in the coating composition of the invention is between 0.001 and 1 .0 wt%. In yet a further aspect the amount of biocide in the coating composition of the inventin is between 0.0001 and 0.1 wt%.

[0057] In still another aspect of the invention, the relative amount of biocide in the emulsion of an alkyd in an aqueous solution wherein the alkyd comprises a biocide according to the invention is less than 10 wt%, or in another embodiment less than 5 wt%. In another aspect it is between 0.01 and 10 wt% of the emulsion. In one embodiment it is between 0.01 and 5 wt%. In yet another embodiment it is between 0.01 and 2.5 wt%. In still another embodiment it is between 0.05 and 5 wt% or between 0.1 wt% and 5 wt % or even between 0.1 and 2.5 wt%.

[0058] In yet another aspect of the invention, the relative amount of insecticide in such an emulsion according to the invention is less than 10 wt%, or in another embodiment less than 5 wt%. In another aspect it is between 0.01 and 10 wt% of the emulsion. In one embodiment it is between 0.01 and 5 wt%. In yet another embodiment it is between 0.01 and 2.5 wt%. In still another embodiment it is between 0.05 and 5 wt% or between 0.1 wt% and 5 wt % or even between 0.1 and 2.5 wt%.

[0059] The emulsion according to the invention can be added to a coating composition to obtain a coating composition with biocide activity. It can also be used to provide biocide activity to other objects, or alternatively, the coating composition comprising the alkyd-encapsulated biocide can be applied to products such as bed nets, clothes, insect repellent nets to cover open windows or doors, or any other object one would like to have biocide activity. So in yet another aspect, the invention relates to an object comprising or soaked in or covered with the alkyd-encapsulated biocide (e.g. insecticide) obtainable / obtained with the method of the invention. In one embodiment the biocide is an insecticide, in still another embodiment the insecticide is deltamethrin.

[0060] In still another aspect the invention relates to a container comprising the emulsion of an alkyd comprising a biocide in a aqueous solution according to the invention, or in another embodiment to a container comprising a coating comprising said emultion. In one embodiment the biocide is an insecticide, in yet another embodiment the insecticide is deltamethrin. [0061 ] It is understood that substrates can be coated with a coating composition comprising the emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide as herein defined, using application methods known in the art such as spraying, applying by brush or roller, soaking of the substrate in the paint, etc. Substrates can be fully coated or partially coated. After drying of the coating, the substrate is covered or partially covered, by a dried coating film which has biocidal activity, e.g. insecticidal activity so that when insects touch the coated part of such a substrate, they suffer from the insecticidal activity of the insecticide present in the coating. So, in still another aspect, the invention relates to a substrate or part thereof, coated with such a coating composition. After curing / drying of such a coating layer, the dried coating layer slowly releases the biocide. Likewise, the invention also relates to a coating process comprising the step of coating a substrate with a coating composition comprising the emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide as herein defined. Substrates obtained in such a process are also part of the invention.

[0062] In one aspect the invention relates to a substrate coated with a coating deposited from a coating composition according to the invention (i.e. comprising the emulsion of an alkyd in an aqueous solution of the invention) or to a substrate coated with an emulsion deposited from the emulsion according to the invention.

[0063] In a further aspect the invention relates to the use of a coating composition according the invention a varnish, lacquer, paint, coating, stain, enamel, printing ink or floor covering, preferably in a varnish, lacquer, paint, or coating.

[0064] The invention is illustrated by means of the following non-limiting examples.

Examples Eight (8) different alkyd resins were used for the encapsulation. Characteristics of these alkyds are provided below

Alkyd Ϊ 2 3 4

Number

Type Urethane modified Long oil Long oil Long high solids unsaturated unsaturated unsaturated unsaturated polyester based on polyester based polyester based polyester based soyabean oil on soyabean oil on soyabean oil on tall oil fatty acid

Oil 63.0% 66.7% 61 .3% 84.1 %

Length

Oil Soya Soya Soya TOFA

Polyol Pentaerythritol Pentaerythritol Pentaerythritol Pentaerythritol

Solids 57.0 - 59.0% 74.0 - 76.0% 64.0 - 66.0% 98.5 - 100%

Acid <2 5 - 10 9 - 11 6 - 10

Value

Solvent White Spirit/xylene White White Xylene

Spirit/xylene Spirit/xylene

Alkyd 5 6 7 8

Number

Type Long high solids A short oil Urethane Alkyd unsaturated polyester unsaturated resin

based on tall oil fatty polyested based

acid on tall oil fatty acid

Oil 85.7% 55.0% 40.0% 59.0%

Length

Oil TOFA TOFA Soya

Polyol Pentaerythritol Pentaerythritol Pentaerythritol

53.0%

Value

Solvent Xylene MEK N/A Xylene

[0065] Different encapsulation method were used to test their impact on product stability: Indirect emulsification method [0066] A mixture of surfactants [non-ionic (Maxemul 7101 - formerly Atlas G5000 [a non-ionic surfactant commercialised by Croda Coatings & Polymers]): anionic (Empimin OT75 [a di-alkyl sulphosuccinate by Huntsman]) surfactants, ratio 55:45 % weight/weight] was used. Also best results were achieved when the alkyd was neutralized to 75 % of the acid value using sodium hydroxide (i.e. enough sodium hydroxide was added to lower the acid value by 75% from the initial value).

[0067] A jacketed stainless steel vessel preheated to 65 °C, was charged with the alkyd, surfactant, biocide (deltamethrin) and antifoam and stirred for 5 minutes at 500 rpm using an overhead stirrer and a blade specially designed for emulsification. Separately water was preheated to a similar temperature. After 5 minutes, a 1 M aqueous solution of NaOH was added dropwise over 5 minutes, whilst increasing the mixing speed to 2000 rpm. Following addition, mixing was allowed to continue for a further 30 minutes. At the end of the mixing the emulsion was transferred to a storage container and allowed to cool to room temperature.

[0068] The indirect method was tried on two different alkyds: numbers 3 and 2. The particle size distribution was similar in both cases (d(0.5) was about 4.3 micron). The size of the emulsion varied little with time and 10-15 minutes of mixing time was enough to achieve the desired particle size.

Direct emulsification method

[0069] The encapsulation method using direct emulsification consisted of the following steps. First a 5 % weight solution of surfactant (polyvinylalcohol with a molecular weight of 31000 g/mol and 88 mol% hydrolysis, commercial name Mowiol ® 4-88 (Sigma-Aldrich)) in water was prepared and heated to 60 °C. Separately deltamethrin (100 % purity) was added to the alkyd resin to which 10 % weight solvent (methyl ethyl ketone) had been added. The alkyd solution was mixed and heated to 60 °C until the deltamethrin was completely dissolved. The emulsion was prepared at 60 °C by adding the alkyd solution into the aqueous solution and mixing at high speed (at least 4000 rpm, the higher the lower the final particle size) for 10 minutes using a high shear mixer (Silverson). After emulsification the solution was allowed to cool and the solvent (methyl ethyl ketone) was removed using a rotary evaporator. The removal of the solvent was confirmed gravimetrically: the quantity of solvent (methyl ethyl ketone) was known from the formulation (already present in the alkyd) and monitored during the removal of the solvent until the mass of the solution has decreased by the quantity of the solvent present.

[0070] The resulting emulsion was highly similar to the ones obtained with the indirect method. The particle size distribution (d(0.5) varied between 2 (4%wt relating to the total quantity of emulsion surfactant) and 3 (6%wt surfactant) micron. Particle size could be varied by changing parameters such as type of surfactants, mixing speed, process temperature or neutralization of the alkyd.

Paricle size distribution measurement

[0071 ] The particle size was measured using Mastersizer 2000, an instrument manufactured by Malvern. The instrument uses laser diffraction to determine the particle size based on Mie Theory. In this technique the particle size is determine by analysing the scattering pattern of the particles. The model number is MAL 1024504. The software used was supplied by manufacturer and it was version 5.6. The measurement was done using standard operating procedures using a value of 1 .54 for the refractive index of alkyd. A typical measurement involves the following steps: cleaning of the dispersing unit, filling with demineralized water, adding a quantity of dispersant (if needed), circulating the mixture through the measuring cell, measuring the background level, adding a quantity of alkyd until an obscuration of 2-10% is obtained, measuring the sample 3 consecutive times and calculating the average.

Deltamethrin isomer content determination

[0072] Normal-phase liquid chromatographic methods using a chiral column was used to resolve the stereoisomers of the pyrethroid insecticides such as deltamethrin. Such methods are described for example by A. Navas Diaz et al (A. Navas Diaz et al., Journal of Chromatographic Science 1998, 36, pp 210- 216) or by R. James Maguire (R. James Maguire, J. Agric. Food Chem. 1990, 38, pp 1613-1617).

STEM-EDX imaging

[0073] In STEM a finely focused electron beam (1 nm) is rastered across a thin (50-100 nm) sample. At each raster point both the transmitted electrons and the emitted X-rays are captured. This yields an electron image showing a projection of the area of interest and element maps of the relevant elements. Thin samples of the liquid dispersion were created by sectioning of the frozen liquid with an ultramicrotome, followed by water evaporation. [0074] A Jeol 2010 FEG TEM, equipped with a Gatan US100 CCD camera, a STEM unit and EDX analyser was used for these measurements. The instrument was operated at 200 keV. The EDX analyzer is a SDD detector from Thermo Scientific, which comes with NS6 software for electron image acquisition and X-ray acquisition and data evaluation. Biological efficacy measurement using the cone test method

[0075] The cone test has been used to determine the bio efficacy of the prepared materials against mosquitoes. The bio efficacy of the materials is usually expressed at % of mosquitoes knocked down and dead after expose to panels painted with biocide (in this case deltamethrin)-comprising paint. The test is described below.

[0076] Mosquitoes, Anopheles Stephens/, were obtained. Only female mosquitoes aged between 2-5 days old were used in the experiments. Prior to testing, mosquitoes were supplied with sugar water, but had not received a blood meal. [0077] Ten female mosquitoes were confined onto a painted panel via a cone (approx. 10 cm base diameter) for a period of six hours. A piece of cotton wool was placed into the neck of the cone to prevent the mosquitoes from escaping. The panels were tested at an approximate 45° angle. Following a six hour confinement in the cone, mosquitoes were removed and placed into clean plastic half pint pots, covered with fleece netting, secured with an elastic band, and provided with sugar water (cotton wool pad soaked in sugar solution).

[0078] Assessments of knockdown and mortality were performed at 0.5, 1 , 1 .5, 2, 3, 5, 6, 24 and 48 hours post initial exposure. Temperature was typically ca. 26 °C ±3, with relative humidity ranged between 30 % and 45 % throughout the experimental period. Three replicates were conducted for each panel.

Deltamethrin containing emulsions

[0079] Using the direct emulsification method, an emulsion was prepared of all 8 alkyds as listed above. The target particle size was set at 5 micron, and some variation in particle size is observed depending on the type of alkyd. No optimization of particle size had been done. Deltamethrin - a pyrethroid type of insecticide - was used added as biocide at 0.5 and 1 .0 wt%. The median particle size for the different emulsions is shown in Figure 1 . In this way different emulsions were obtained with an a median particle size d(0.5) varying between 2.3 micron (alkyd number 3; 0.5 wt% deltamethrin) to 9.1 micron (alkyd number 4; 0.5 wt% deltamethrin).

[0080] In order to prove that deltamethrin was encapsulated into discrete alkyd particles, STEM-EDX imaging was used. The presence of a bromine atom on the deltamethrin molecule provided a useful handle for identification and location of the insecticidal material.

[0081 ] Imaging by STEM-EDX of an emulsion of the invention (alkyd number 5) containing 1 % of deltamethrin indicated that bromine was limited in location significantly to the resin particles with bromine shown to be homogenous across the particle. [0082] SEM imaging further revealed that deltamethrin was encapsulated in the alkyd matrix i.e. matrix encapsulation, not core shell. In other words, the active is evenly distributed throughout the alkyd, not localised in a central core/wall structure. Accordingly, in one aspect, the biocide in the emulsion of an alkyd in an aqueous solution of the invention is matrix encapsulated in the alkyd. Storage stability of emulsions

[0083] Emulsion stability upon storage is an important property as it allows longer time between encapsulation and application of the encapsulated biocide, e.g. in paint formation. [0084] An emulsion of alkyd number 3 was prepared using the direct method. After preparation i.e. after 0 days of storage) the average particle size d(0.5) was about 2.3 micron (between 2.0 and 2.5 micron). The emulsion was stored in a closed flask at room temperature and the average particle size d(0.5) was measured at 16, 24 and 84 days of storage. These measurements revealed that the average particle size d(0.5) was stable during storage as the average particle size d(0.5) remained between 2.0 and 2.5 micron.

[0085] Likewise an emulsion of alkyd number 8 comprising deltamethrin was stored for 68 days. During storage the average particle size d(0.5) remained stable (i.e. about 4 micron). [0086] In both emulsions (of alkyd number 3 and 8) some settling of the emulsion was observed during storage, but the emulsions were easy redispersible using low-shear mixing suggesting that the emulsion droplets are rigid enough to preserve their shape upon storage.

Stability of deltamethrin encapsulated in alkyd emulsions

[0087] The main purpose for encapsulation is to provide the active (biocide or insecticide such as deltamethrin) with protection against racemization and degradation. After preparation, samples were stored for three weeks at 54°C which is taken as indicative for three years of ageing at room temperature.

[0088] Samples were prepared by dosing alkyd-encapsulated deltamethrin to an active content level of 0.01 % weight into a white waterbased wall paint in the PVC range of 20 - 80 (commercial paint of AkzoNobel). The paint was adjusted to pH 8, 9 and 10 and the samples were incubated at 54 °C for three weeks. HPLC measurements were performed at 0, 4, 7, 10, 14, 17 and 21 days to determine deltamethrin stability using the method as described elsewhere herein. The results were compared with samples containing the standard drop in (deltamethrin as 25 g/L suspension concentrate by Bayer). The paint was adjusted to pH 8, 9 and 10 and the samples were incubated at 54 °C for three weeks. [0089] The results for standard drop-in are presented in Figure 2 which shows the decrease rate of % active isomer over time as a function of pH. As expected, more alkaline environments increase the racemization rate with the strongest effect observed for pH 10. This experiment indicated a nearly 20 % drop in active content at pH 9 while at pH 8 the drop is 10 % after 21 days of storage (actual measurement was done after 22 days).

[0090] The results obtained for samples where deltamethrin was encapsulated are presented in Figure 3 for very long oil alkyds (Figure 3A pH=8; Figure 3B pH=9 and Figure 3C pH=10), Figure 4 for long oil alkyds (Figure 4A pH=8; Figure 4B pH=9 and Figure 4C pH=10),and Figure 18 for short and medium long oil alkyds (Figure 5A pH=8; Figure 5B pH=9 and Figure 3C pH=10). Overall encapsulation into alkyds leaded to an improvement in stability against racemization especially at pH 8 and 9. At pH 10 very long alkyds provided some small improvement. It is noted that especially at pH =10, racemization starts during preparation. Due to the time between preparation and first measurement (up to some hours) the deltamethrin activity is less than 100 %. Acid value did not seem to impact on the performance of alkyds as encapsulation mediums and there was no significant difference between long oil alkyds and very long oil alkyds. Overall, very long oil alkyds performed better due to the fact that they are high solids alkyds with only 2 % weight solvent as compared to 35 % for long oil alkyds. A lower solvent content is desirable because it adds a lower VOC penalty and it simplifies the production method since an additional step of solvent removal is not needed. It also reduces the diffusion of deltamethrin out of the encapsulation which is thought to be mediated by solvent. Biological efficacy of alkvd-encapsulated biocide [0091 ] Encapsulation of the deltamethnn in very long oil alkyds improved the stability against racemization especially at pH 8 and 9 as shown above. But for encapsulation to be useful the active, in this case deltamethrin, also needs to have a bioavailability and efficacy against mosquitoes similar or better than the standard drop-in (of a 25 g/L of deltamethrin suspension concentrate in paint). A significant lower efficacy against mosquitoes is indicative that the encapsulation is too efficient and it prevents the migration of deltamethrin to the surface of the paint.

[0092] The biological effect of the prepared encapsulations of deltamethrin in alkyd number 6 (a medium oil length alkyd) was tested by incorporating the encapsulations in a white waterbased wall paint in the PVC range of 20 - 80 using a styrene acrylic latex and Optifilm OE300 (Eastman Chemicals) as coalescent and a total content of deltamethrin of 0.01 % weight. The particle sizes of the alkyd 6 encapsulation-deltamethrin are presented in Table 1 . The films were tested using the cone test method as herein described. The bio efficacy of the tested panels is expressed as % of mosquitoes knocked down and dead after exposure to the panels.

Table 1 The particle size of the different emulsions based on alkyd number 6

[0093] The bio efficacy results for the tested variants of encapsulations of deltamethrin in alkyd number 6 in the white waterbased wall paint in the PVC range of 20 - 80 were compared to freshly prepared standard drop-in compositions of deltamethhn in the same paint formulation (pH = 8, 0.01 wt% deltamethrin). The results of this comparison are shown in Figure 6.

[0094] The results indicate that none of the tested variants performed better than the freshly prepared standard drop-in where 95 % of mosquitoes are knocked down and dead after 5 hours. The alkyd number 6 variants exhibited a wide variation of efficacy against the tested mosquitoes, ranging from poor for variant 6 (40 % of mosquitoes knocked down and dead after 48 hours) to similar to the standard drop-in for variant 2 (85 % of mosquitoes knocked down and dead after 6 hours. [0095] In addition to the bio efficacy of the biocide encapsulated in the medium length alkyd, the bio efficacy of deltamethrin encapsulated in a very long oil alkyd (alkyd number 5) was tested in a similar way using the cone test method. The encapsulated material was incorporated in a white waterbased wall paint in the PVC range of 20 - 80 using standard vinyl acetate as latex at 0.1 % weight active level. The results from the test are presented in Figure 7 and they indicate similar levels of efficacy against the tested mosquitoes as the paint that only just received the drop-in. The standard drop-in show a better efficacy for the initial period but the difference between the samples is very close to the experimental error of the measurement. [0096] The above experiments show that the release of the biocide ( in these examples deltamethrin) from a coating composition is sufficient to kill mosquitoes at a similar or slightly lower level as in a freshly prepared drop-in composition. The examples further show that racemization of the biocide is significantly lower when it is encapsulated in an alkyd using the method of the invention. The significantly lower levels of racemization compensate for the slight reduction in biological activity due to the encapsulation of the biocide by the alkyd.

Encapsulation of other pesticides in alkyd [0097] The alkyd encapsulation method used for deltamethrin was tested for other pesticides to determine its feasibility. Permethrin (cis enantiomer) is another biocide part of pyrethroid class of insecticides.

[0098] Samples were prepared using very long oil alkyds (numbers 4 and 5) in process similar to the one used for deltamethrin, namely direct emulsification. The emulsification method resulted in a particle size distribution of the emulsions at the end of the process of 5 microns for alkyd number 4 and 10 microns for alkyd number 5. So, the emulsions with permethrin have similar mean particle size to the ones with deltamethrin.

Claims

An emulsion of an alkyd in an aqueous solution characterized in that the alkyd comprises a biocide and the aqueous solution comprises between0.1 and 10 wt% of surfactant; wherein the amount of non-aqueous solvent is less than 15 wt%, preferably less than 10 or 5 wt%. The emulsion of claim 1 wherein the alkyd oil length is higher than 60%, preferably wherein the alkyd oil length is higher than 75%. The emulsion of claim 1 or 2 wherein the emulsion comprises between 20 and 60 % non-volatiles, preferably between 35 and 50% non-volatiles.The emulsion of any of the preceding claims wherein the pH of the emulsion is between 7 and 1 1 , preferably between 8 and 10, or wherein the pH of the emulsion is between 8 and 9. The emulsion of any of the preceding claims wherein the amount of biocide in the emulsion is less than 10 %wt, or wherein the amount of biocide in the emulsion is between 0.01 and 5 wt%. The emulsion of any of the preceding claims wherein the biocide is an insecticide; preferably wherein the insecticide is a pyrethroid or pyrethrin; or wherein the insecticide is a pyrethroid; more preferably wherein the insecticide is selected from the group consisting of permethrin, deltamethrin and cypermethrin; even more preferably wherein the insecticide is deltamethrin. A process for preparing the emulsion of anyone of claims 1 to 6, comprising the steps of:

1. providing an aqueous solution of a surfactant comprising between 0.1 and 10 wt% of surfactant,

ii. providing an alkyd optionally dissolved in a solvent,

iii. providing a biocide,

iv. dissolving the biocide in the alkyd, v. emulsifying the biocide dissolved in the alkyd of step iv in the aqueous solution of step I,

vi. optionally removing the solvent of step ii,

vii. optionally adjusting the pH of the emulsion to a value between 7 and 1 1 , preferably between 8 and 10, or to a value between 8 and

9.

8. The process of claim 7 wherein in step v the emulsion is prepared by adding the aqueous solution into the alkyd, or by adding the alkyd into the aqueous solution; preferably by adding the alkyd into the aqueous solution.

9. An emulsion of an alkyd in an aqueous solution obtainable by the process of claim 7 or 8.

10. A coating composition comprising the emulsion of anyone of claims 1 -6 or 9.

1 1 . The coating composition according to anyone of claims 9-10 wherein the amount of biocide is between 0.0001 and 5 wt%, or wherein the amount of insecticide in the coating composition is between 0.0001 and 5 wt%, preferably wherein the amount of biocide is between 0.0001 and 0.1 wt%.

12. The coating composition according to anyone of claims 9 to 1 1 wherein the pH of the coating composition is between 7 and 1 1 , preferably between 8 and 10, or wherein the pH of the coating composition is between 8 and 9.

13. A substrate coated with a coating deposited from a coating composition according to any one of claims 10 to 12; or

a substrate coated with an emulsion deposited from the emulsion according to any one of claims 1 to 6 or 9.

14. A coating process comprising the step of coating a substrate with the coating composition of any one of claims 10 - 12.

15. Use of a coating composition according to anyone of claims 10 to 13 in a varnish, lacquer, paint, coating, stain, enamel, printing ink or floor covering.