FIELD OF THE INVENTION

The present invention relates to encapsulated quaternary ammonium compounds and their use in paint compositions. The present invention also relates to paint compositions comprising such encapsulated quaternary ammonium compounds.

BACKGROUND OF THE INVENTION

Biocides are chemical compounds that are known to inhibit the growth or kill microorganisms such as bacteria, algae, fungus, viruses and parasites. Therefore, these have been extensively used in application areas such as paints and coatings, marine, building and construction, medicines, agriculture, home care and consumer care products. In the area of paints and coatings, these biocides can act as both in- can and dry-film preservatives. Some preferred biocidal compounds used in the area of paints and coatings are n-(3,4-dichlorophenyl)-n, n-dimethyl urea (Diuron), triclosan, 4, 5-dichloro-2-n-octyl-3(2H)-isothiazolone (DCOIT), 2-n-octyl-3(2H)- isothiazolone (OIT), zinc pyrithione, benzisothiazolone (BIT), alkyl derivatives thereof, and mixtures thereof.

One of the most common biocides used by paint and coatings industry is Diuron which acts as an algaecide. Though, it is categorized as carcinogenic category 2, Diuron has been widely used for coating either as free active ingredient or in combination with other biocides or by encapsulating the compound with polymeric shell such as urea-formaldehyde, melamine-formaldehyde, polyurea, etc (EP2801256A1 , EP2967032A1 ). The availability in ample amount, easy processibility in the paint, low cost and achievement of desired performance makes Diuron a preferred candidate for antialgal application. However, usage of Diuron in excess and usage of hazardous materials like formaldehyde/polyisocyanate in the encapsulation process causes environmental hazards to human and aquatic life due to their carcinogenic nature.

In recent years, use of Quaternary ammonium compounds (QAC) as antimicrobial agents has increased tremendously in the healthcare and consumer care application due to its enhanced efficacy, safety, and low human and environmental toxicity. As QAC also acts as an algaecide, it can be considered as a promising candidate to replace the conventional algaecides like Diuron. Since a few years, researchers have been exploring the incorporation of QAC in water-based paint formulations for antimicrobial activity. However, QACs, are water soluble and due to their cationic nature, react with the anionic counterpart of the paint causing gelation and precipitation in the paint formulation thereby increasing the viscosity. This leads to compatibility issue, change in texture of paint and an instability of the paint formulation during storage.

Prior art (WO 2013095743 A1) has tried to overcome this problem of gelation by complexing the QAC with compatible polymers. The publication describes an antimicrobial paint formulation comprising quaternary ammonium compound, latex polymer, pigments and water. The latex binder resins are selected based on their compatibility with the QAC and thereby precipitation of QAC is prevented.

Although the publication describes that the QAC can be encapsulated in a microcapsule, details of encapsulation are not provided. The publication further mentions that QAC from these microcapsules gets released when the paint dries off causing the microcapsules to burst upon drying. However, it fails to show the release of the encapsulated QAC and also fails to demonstrate stability of the paint formulation containing QAC in an encapsulated form and the antimicrobial activity of that formulation.

EP 0328335A1 , US 5096488 A and US 4990557A describe coating compositions with long-lasting anti-fouling properties, comprising QACs and inorganic fillers. However, the fillers used are in very low percentage (upto 20%) and therefore, incapable of acting as entrapping agents for the QACs. They have only been used to increase the bulk of the compositions.

US20160183520 A1 discloses co-encapsulated biocides including QACs by chemisorption method, however, the process for encapsulation is lengthy and cumbersome requiring more than 72 hours for completion. Also, the QACs are used to modify clay and make it hydrophobic and hence, higher loading of the QAC cannot be achieved. The other active ingredients used for encapsulation along with QAC, such as IPBC, OIT, THPS, are hazardous and there may be concerns about health and environmental safety.

CN105746513 discloses the use of QACs for killing underwater organisms by mixing them with carriers such as attapulgite clay and quartz sand. This may be then coated with a sustained release film. However, the sustained release film used is such that can only prolong the release for 48 hours and not more. Also, the process involves purification of the carrier and hence, has multiple steps and is cumbersome.

None of these publications provide any long-term storage stability data for the paint compositions containing the QACs.

Thus, there is an unmet need to have stable and environmentally safe paint compositions comprising QAC that 1) do not have precipitation leading to increased viscosity during in-can storage and, 2) provide reasonably good and long-lasting antialgal protection post-application.

Surprisingly, it has been found that by entrapping QAC into an inorganic carrier, and then optionally coating the inorganic carrier with organic polymers, the gelation of QAC gets retarded thereby maintaining the viscosity of the paint formulation. Furthermore, such encapsulated quaternary ammonium compounds offer improved in-can storage stability and controlled release of the QAC post application, when used in paint formulations.

SUMMARY OF THE INVENTION

Accordingly, in a first aspect, the present invention provides for a stable paint composition comprising an encapsulated quaternary ammonium compound, which is in form of a core comprising a blend of at least one quaternary ammonium compound with at least one non-ionic surfactant, wherein said blend is entrapped in an inorganic carrier, wherein, the non-ionic surfactant has a HLB value above 7, and wherein the inorganic carrier comprises from 30 to 80 wt.-% of the core.

In a second aspect the invention provides for a method of preparing paint compositions comprising encapsulated quaternary ammonium compounds, comprising i. blending at least one quaternary ammonium compound with at least one non-ionic surfactant and optionally at least one wax, ii. entrapping this blend in an inorganic carrier to form a core, and iii. optionally coating the core with a first monomer and then optionally with a second monomer to form a polymeric shell by polymerization of said monomer or monomers, wherein the method is solvent-free.

The encapsulated quaternary ammonium compounds, when added to paint formulations, provide improved stability to the paint formulations during in-can storage. They also show antimicrobial efficacy and offer controlled release of the QAC post application i.e. , from dry film. The encapsulated quaternary ammonium compounds also provide better compatibility with the paint formulations, do not show gelation or precipitation in the paint formulations and hence, exhibit improved storage stability.

DETAILED DESCRIPTION OF THE INVENTION

In this document, including in all embodiments of all aspects of the present invention, the following definitions apply unless specifically stated otherwise. All percentages are by weight (w/w) of the total composition. Total composition is to be understood to relate to the combination of A, B and C. All ratios are weight ratios. “wt.-%” means percentage by weight. References to ‘parts’ e.g. a mixture of 1 part X and 3 parts Y, is a ratio by weight. All ranges are inclusive and combinable. The number of significant digits conveys neither a limitation on the indicated amounts nor on the accuracy of the measurements. All measurements are understood to be made at 23°C and at ambient conditions, where “ambient conditions” means at 1 atmosphere (atm) of pressure and at 50% relative humidity. “Relative humidity” refers to the ratio (stated as a percent) of the moisture content of air compared to the saturated moisture level at the same temperature and pressure. Relative humidity can be measured with a hygrometer, in particular with a probe hygrometer from VWR ^® International. Herein “min” means “minute” or “minutes”. Herein “mol” means mole. Herein “g” following a number means “gram” or “grams”. “Ex.” means “example”. All amounts as they pertain to listed ingredients are based on the active level (‘solids’) and do not include carriers or by-products that may be included in commercially available materials. Herein, "comprising" means that other steps and other ingredients can be in addition. “Comprising” encompasses the terms "consisting of" and "consisting essentially of". The compositions, formulations, methods, uses, kits, and processes of the present invention can comprise, consist of, and consist essentially of the elements and limitations of the invention described herein, as well as any of the additional or optional ingredients, components, steps, or limitations described herein. Embodiments and aspects described herein may comprise or be combinable with elements, features or components of other embodiments and/or aspects despite not being expressly exemplified in combination, unless an incompatibility is stated. “In at least one embodiment” means that one or more embodiments, optionally all embodiments or a large subset of embodiments, of the present invention has/have the subsequently described feature. Where amount ranges are given, these are to be understood as being the total amount of said ingredient in the composition, or where more than one species fall within the scope of the ingredient definition, the total amount of all ingredients fitting that definition, in the composition.

“Quaternary ammonium compounds” refers to salts of quaternary ammonium compounds and are explained in detail below, and which act as algicidal/ antimicrobial agents. “Water-soluble” refers to any material that is sufficiently soluble in water to form a clear solution to the naked eye at a concentration of 0.1 % by weight of the material in water at 25°C. The term “water-insoluble” refers to any material that is not “water-soluble”.

“Core” refers to the blend of at least one quaternary ammonium compound and at least one nonionic surfactants being entrapped in an inorganic carrier.

First Aspect

In a first aspect, the present invention relates to stable paint compositions comprising encapsulated quaternary ammonium compounds comprising a core which has at least one quaternary ammonium compound (a) of the formula (I) wherein at least one of R ¹ , R ² , R ³ and R ⁴ are each selected from an aliphatic group of from 8 to 30 carbon atoms, an aromatic, alkoxy, polyoxyalkylene, alkylamido, hydroxyalkyl, aryl, or an alkylaryl group having up to 22 carbon atoms; the remainder of R ¹ , R ² , R ³ and R ⁴ are independently selected from the group consisting of an aliphatic group consisting of from 1 to 22 carbon atoms, and an aromatic, alkoxy, polyoxyalkylene, alkylamido, hydroxyalkyl, aryl or alkylaryl group having up to 22 carbon atoms; and X is selected from the group consisting of halide, carbonate, methosulfate, saccharinate, or anions of organic or inorganic acid such as chloride, bromide, acetate, propionate, benzoate, sulfate.

Suitable examples of quaternary ammonium compounds include, but are not limited to n-alkyl (Cs-Cis) dimethyl benzyl ammonium chlorides, benzalkonium chloride (where the alkyl side chain is Cs, Cio, C12, Cu, C16 or C18 or mixtures thereof), n-alkyl (Cs-Cis) dimethyl ethylbenzyl ammonium chlorides, dialkyl dimethyl ammonium chlorides (where the alkyl side chain is C6-C12), n-alkyl dimethyl benzyl ammonium chloride, and didecyl dimethyl ammonium chloride, octyl decyl dimethyl ammonium chloride, dioctyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, octyl-trimethylammonium bromide, decyl- trimethyl-ammonium chloride, didecyl-dimethylamrnoniurn chloride, dedecyl- methylhydroxyethylammonium propionate, lauryl-trimethylainmonium chloride, lauryl-pyridinium chloride, hexadecyl- trimethylammoniurn chloride, stearyl- trimethylammonium chloride and stearyl- dimethylbenzylammonium chloride, ditallow dimethyl ammonium chloride, C12/14 alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl benzyl ammonium chloride, cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, alkyl hydroxyethyl dimethyl ammonium chloride, distearyl dimethyl ammonium chloride, dihydrogenated tallow fatty alkyl dimethyl ammonium chloride, and mixtures of the same. A variety of useful quaternary ammonium compounds are commercially available including, but not limited to Barquat ^® MB-50, Barquat ^® MB~8Q, and Bardac ^® 2250 quaternary ammonium compounds available from Lonza, Inc., BTC ^® 1 Q10, BTC ^® 2125, BTC ^® 818-S0% available from Stepan Company, Dodigen 1611 , Clouding Quat 158, Dodigen 226,

Dodigen 226 K, Dodigen 661 -RB, Dodigen 800, Dodigen 1611 S,

Dodigen 1611-30, Dodigen 1828, Dodigen 2541 , Dodigen 2541 cone,

Dodigen 2808, Dodigen 2808/L, Dodigen 2808 S, Dodigen 2809, Dodigen 2809-L, Dodigen 5343, Dodigen 5462-2, Dodigen V 5065, and the like.

In certain preferred embodiments, the quaternary ammonium compounds (a) of the present invention are further optionally blended with at least one wax (b), which is water soluble or water insoluble. Waxes are organic compounds that contain long alkyl chains. They may also contain various functional groups, such as fatty acids, primary and secondary long chain alcohols, unsaturated bonds, aromatics, amides, ketones and aldehydes. Waxes frequently contain fatty acid esters.

Waxes (b) that may be used in the present invention may, for example, be synthetic waxes, animal-derived waxes, plant-derived waxes or montan waxes. In preferred embodiments, the at least one wax (b) is a water-insoluble wax. Preferred waxes comprise mono esters. Also preferred waxes comprise fatty acid esters.

More preferred waxes comprise esters of fatty acids with fatty alcohols. Examples of esters of fatty acids with fatty alcohols are esters of fatty acids having 8 to 24 carbon atoms with fatty alcohols having 8 to 24 carbon atoms, preferably esters of fatty acids having 8 to 20 carbon atoms with fatty alcohols having 8 to 20 carbon atoms, more preferably esters of fatty acids having 12 to 18 carbon atoms with fatty alcohols having 12 to 18 carbon atoms, particularly preferably esters of fatty acids having 14 to 18 carbon atoms with fatty alcohols having 14 to 18 carbon atoms. The fatty acids may be saturated and/or unsaturated. Unsaturated fatty acids may have one or more carbon-carbon double bonds. Preferably, the fatty acids are saturated.

In preferred embodiments, the waxes (b) have melting points in the range of 40 - 120°C, more preferably from 45 - 110°C, and most preferably from 50 - 100°C.

A particularly preferred wax (b) comprises partly saponified ester of montanic acid, which is commercially available, e.g., as Ceridust ^® 5551. Its melting point is in the range of from 86 to 98°C.

Another particularly preferred wax (b) is an amorphous low molecular weight propylene-ethylene-copolymer wax, which is commercially available, e.g., as Licocene ^® PP 1302. Its melting point is in the range of from 87 to 93°C.

Another particularly preferred wax (b) is crystolive wax. Crystolive wax (INCI name: Olea Europaea (Olive) Oil Unsaponifiables) is a wax present in the unsaponifiable fraction of olive oil. Its melting point is in the range of from 46 to 56°C. Another particularly preferred wax (b) is olive wax. Olive wax (INCI name: Hydrogenated Olive Oil) is a natural wax derived from pure olive oil. Its melting point is in the range of from 58 to 66°C.

Another particularly preferred wax (b) is cetyl palmitate. Cetyl palmitate is a water- insoluble wax derived from sperm whales and coral reefs. Its melting point is in the range of from 50 to 55°C.

If present, the amount of wax (b) that is blended with the quaternary ammonium compounds (a) ranges from 1 to 20 wt.-%, more preferably from 5 to 15 wt.-% and most preferably from 7 to 12 wt.-% of at least one wax, based on the total weight of the encapsulated QAC.

The quaternary ammonium compounds (a) are blended with at least one non-ionic surfactant (c) having a HLB value above 7. The amount of non-ionic surfactants (c) that can be blended with quaternary ammonium compounds (a) of the present invention can vary over a broad range. In at least one embodiment, the composition of the invention comprises a total amount of surfactant of from 0.01 wt.-% to 20 wt.-%, from 0.1 wt.-% to 15%, from 1 wt.-% to 12%, from 2 wt.-% to 10 wt.-%.

Preferred surfactants are water soluble surfactants.

Non-ionic surfactants that can be included in compositions of the invention include condensation products of aliphatic primary or secondary linear or branched chain alcohols or phenols with alkylene oxides, usually ethylene oxide and generally having from 6 to 30 ethylene oxide groups. In at least one embodiment the non ionic surfactants are alkyl ethoxylates having the formula:

R-(OCH ₂ CH ₂ ) _n OH, where, R is an alkyl chain of C12 to C15, and n is 5 to 9. Other suitable non-ionic surfactants include mono- or di-alkyl alkanolamides. Examples include coco mono- or di-ethanolamide and coco mono-isopropanolamide.

Further non-ionic surfactants which can be included in compositions of the invention are the alkyl polyglycosides (APGs). Typically, APG is one which comprises an alkyl group connected (optionally via a bridging group) to a block of one or more glycosyl groups. Preferred APGs are defined by the following formula:

RO-(G) _n wherein,

R is a branched or straight chain alkyl group which may be saturated or unsaturated and G is a saccharide group. R may represent a mean alkyl chain length of from about C5 to about C20. Preferably R represents a mean alkyl chain length of from about C9 to about C12. G may be selected from C5 or Ce monosaccharide residues and is preferably a glucoside. G may be selected from the group comprising glucose, xylose, lactose, fructose, mannose and derivatives thereof. Preferably G is glucose. The degree of polymerisation, n, may have a value of from about 1 to about 10 or more. Most preferably the value of n lies from about 1 .3 to about 1 .5. Suitable alkyl polyglycosides for use in the invention are commercially available and include for example those materials identified as: Oramix NS 10 ex Seppic; Plantaren 1200 and Plantaren 2000 ex Henkel.

Other sugar-derived non-ionic surfactants which can be included in compositions of the invention include the fatty (e.g. C-IO-C-IS) N-alkyl (Oi-Ob) polyhydroxy fatty acid amides, such as the C12-C18 N-methyl glucamides, as described for example in WO9206154 and US5194639, and the N-alkoxy polyhydroxy fatty acid amides.

In at least one embodiment, the non-ionic surfactant has an HLB (Hydrophilic Lipophilic Balance) of greater than 7. Particularly preferred non-ionic surfactants are polyoxyethylene Ci2-Ci8-fatty alcohol ethers with ethoxylation degrees from 10 to 150 and preferably from 15 to 120 and more preferably being selected from the group consisting of ethoxylated lauryl alcohol and ethoxylated stearyl alcohol, each with ethoxylation degrees from 15 to 120 and mixtures thereof.

In at least one embodiment, the non-ionic surfactant has an HLB (Hydrophilic Lipophilic Balance) of greater than 12. Optionally, the non-ionic surfactant is selected from the group consisting of ethoxylated or ethoxylated/propoxylated fatty alcohols with a fatty chain comprising from 12 to 22 carbon atoms, ethoxylated sterols, such as stearyl- or lauryl alcohol (EO-7), PEG-16 soya sterol or PEG-10 soya sterol, polyoxyethylene-polyoxypropylene block polymers (poloxamers), and mixtures thereof.

In at least one embodiment, the non-ionic surfactant is selected from the group consisting of ethoxylated fatty alcohols, fatty acids, fatty acid glycerides or alkylphenols, in particular addition products of from 2 to 30 mol of ethylene oxide and/or 1 to 5 mol of propylene oxide onto Cs- to C22-fatty alcohols, onto C12- to C22-fatty acids or onto alkyl phenols having 8 to 15 carbon atoms in the alkyl group, C12- to C22-fatty acid mono- and diesters of addition products of from 1 to 30 mol of ethylene oxide onto glycerol, addition products of from 5 to 60 mol of ethylene oxide onto castor oil or onto hydrogenated castor oil, fatty acid sugar esters, in particular esters of sucrose and one or two Cs- to C22-fatty acids, INCI: Sucrose Cocoate, Sucrose Dilaurate, Sucrose Distearate, Sucrose Laurate, Sucrose Myristate, Sucrose Oleate, Sucrose Palmitate, Sucrose Ricinoleate, Sucrose Stearate, esters of sorbitan and one, two or three Cs- to C22-fatty acids and a degree of ethoxylation of from 4 to 20, polyglyceryl fatty acid esters, in particular of one, two or more Cs- to C22-fatty acids and polyglycerol having preferably 2 to 20 glyceryl units, alkyl glucosides, alkyl oligoglucosides and alkyl polyglucosides having Cs to C22-alkyl groups, e.g. decylglucoside or laurylglucoside, and mixtures thereof.

In at least one embodiment, the non-ionic surfactant is selected from the group consisting of fatty alcohol ethoxylates (alkylpolyethylene glycols), alkylphenol polyethylene glycols, alkylmercaptan polyethylene glycols, fatty amine ethoxylates (alkylaminopolyethylene glycols), fatty acid ethoxylates (acylpolyethylene glycols), polypropylene glycol ethoxylates (Pluronics ^® ), fatty acid alkylol amides, (fatty acid amide polyethylene glycols), N-alkyl-, N -a I koxy poly-hydroxy-fatty acid amide, sucrose esters, sorbitol esters, polyglycol ethers, and mixtures thereof.

In at least one embodiment, the composition of the invention comprises a fatty N-methyl-N-glucamide surfactant. In at least one embodiment, the fatty N-methyl- N-glucamide surfactant conforms to the formula (X): wherein,

R is a linear or branched alkyl or alkenyl group having from 3 to 30 carbon atoms. In at least one embodiment, R is an alkyl group having from 3 to 30 carbon atoms. In at least one embodiment, R is a saturated aliphatic hydrocarbon group which can be linear or branched and can have from 3 to 20 carbon atoms in the hydrocarbon chain, preferably linear or branched. Branched means that a lower alkyl group such as methyl, ethyl or propyl is present as substituent on a linear alkyl chain. In at least one embodiment, R is selected from the group consisting of

1 -propyl, 2-propyl, 1 butyl, 2-butyl, 2-methyl-1 -propyl (isobutyl), 2-methyl-2-propyl (tert-butyl), 1 -pentyl, 2-pentyl, 3-pentyl, 2-methyl-1 -butyl, 3-methyl-1 -butyl,

2 methyl-2-butyl, 3-methyl-2-butyl, 2, 2-dimethyl-1 -propyl, 1 -hexyl, 2-hexyl, 3-hexyl,

2-methyl-1 -pentyl, 3-methyl-1 -pentyl, 4-methyl-1 -pentyl, 2-methyl-2-pentyl,

3 methyl-2-pentyl, 4-methyl-2-pentyl, 2 methyl-3-pentyl, 3-methyl-3-pentyl,

2,2 dimethyl-1 -butyl, 2,3-dimethyl-1 -butyl, 3,3 dimethyl-1 -butyl, 2-ethyl-1 -butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, 1 heptyl, 1 -octyl, 1-nonyl, 1-decyl,

1 undecyl, 1-dodecyl, 1-tetradecyl, 1-hexadecyl and 1-octadecyl. Suitable fatty N methyl-N-glucamide surfactants are described in WO2013/178700 and EP0550637, which are incorporated herein by reference. In at least one embodiment, the N-methyl-N-glucamide surfactant is selected from those conforming to formula (X), wherein R is C12 alkyl or Cu alkyl. In at least one embodiment, the N-methyl-N-glucamide surfactant is selected from those conforming to formula (X), wherein R is Ci6 alkyl or Ci8 alkyl.

HLB value: The nature of a surfactant can be represented by the hydrophilic- lipophilic balance of the molecule. The degree of this hydrophilic-lipophilic balance can be determined by calculating values for the different regions of the molecule, as described by Griffin in 1949 and 1954. Griffin's method has been primarily developed for non-ionic surfactants and uses the following formula:

HLB = 20 * M _h /M where,

M _h is the molecular mass of the hydrophilic portion of the molecule, and M is the molecular mass of the whole molecule, giving a result on a scale of 0 to 20. An HLB value of 0 corresponds to a completely lipophilic molecule, and an HLB value of 20 corresponds to a completely hydrophilic molecule.

The HLB value as used herein for non-ionic surfactants is calculated by the above formula. The method of Griffin is published, for example, in Journal of the Society of Cosmetic Chemists, 5 (4), 249-256 (1954).

The HLB value as used herein for anionic, or amphoteric surfactants is calculated by the method of Davies. This method is published, for example, in Gas/Liquid and Liquid/Liquid Interfaces. Proceedings of 2 ^nd International Congress Surface Activity, pp. 426-438, Butterworths, London 1957.

The blend comprising the quaternary ammonium compounds of the present invention further is entrapped in an inorganic carrier. The inorganic carriers which may be used in the present invention are selected from precipitated silica, clay, zeolites, fumed metal oxides, pyrogenic metal oxides such as porous silica, pyrogenic aluminum oxide, fumed silica, silica gel, and combinations thereof. The pyrogenic metal oxides may be hydrophilic or hydrophobic and thus partially or fully alkylated.

In at least one embodiment, the inorganic carrier is precipitated silica selected from the group comprising of Sipernat ^® 22; Sipernat ^® 22LS, Sipernat ^® 22S, Sipernat ^® 2200, Sipernat ^® 25, Sipernat ^® 33, Sipernat ^® 50, Sipernat ^® 50S, Sipernat ^® 500LS, Sipernat ^® 101 M, Sipernat ^® 120, Sipernat ^® 160, Sipernat ^® 186, Sipernat ^® 218, Sipernat ^® 266, Sipernat ^® 268, Sipernat ^® 288, Sipernat ^® 298, Sipernat ^® 303, Sipernat ^® 306, Sipernat ^® 310, Sipernat ^® 320, Sipernat ^® 320 DS, Sipernat ^® 32s AP, Sipernat ^® 32s C, Sipernat ^® 340, Sipernat ^® 350, Sipernat ^® 360, Sipernat ^® 622 S, Sipernat ^® 622 LS, Sipernat ^® 62s, Sipernat ^® 680, Sipernat ^® BG-2, Sipernat ^® FPS-5, Sipernat ^® FPS-1 , Sipernat ^® 11 PC, Sipernat ^® 22 PC, Sipernat ^® 2200 PC, Sipernat ^® 44 MS, Sipernat ^® 820A, Sipernat ^® 880, Sipernat ^® D 10, Sipernat ^® D 13, Sipernat ^® D 17 from Evonik Industries, Ibersil ^® D 100, Ibersil ^® D100P or Ibersil ^® D 250 from the IGE Group, Flo-Gard ^® SC-72, Flo-Gard ^® LPC from PPG, M Fill-100 and M Fill- 300 from Madhu Silica.

In certain preferred embodiments, the precipitated silica is characterized by a high liquid absorption capacity, determined as DOA absorption number of at least 120 ml/100g, preferably at least 140 ml/100g, more preferably at least 160 ml/100g precipitated silica. DOA is the abbreviation for di-(2-ethylhexyl) adipate (CAS-number 103-23-1 ). The test method is based on ISO 19246 (“Rubber compounding ingredients- Silica - Oil absorption of precipitated silica”) composition method.

In at least one embodiment, the inorganic carrier is clay selected from the group consisting of natural clays comprising bentonite, montmorillonite, beidellite, saponite, hectorite, stevensite, kerolite-saponite, kerolite, talc, pyrophyllite, attapulgite, sepiolite; a mixture of natural silica with a bentonite; any modified clays; and any mixtures thereof.

In preferred embodiments, the inorganic carrier used for entrapping the blend comprising the quaternary ammonium compound is precipitated silica. The amount of the inorganic carrier that may be used in accord with the present invention ranges from about 30 to 80%. The percentage means that the inorganic carrier accounts for 30 to 80 % of the weight of the core. In preferred embodiments, the amount of the inorganic carrier ranges from about 35 to 70% and most preferably from about 40 to 60%.

The core may optionally comprise additional surfactants selected from anionic or amphoteric surfactants or combinations thereof. Amphoteric or zwitterionic surfactants which can be included in the composition of the present invention are selected from the group consisting of N-(Ci2-Ci8)-alkyl-beta-aminopropionates and N-(Ci2-Ci8)-alkyl-beta-iminodipropionates as alkali metal salts and mono-, di-, and trialkylammonium salts; N-acylaminoalkyl-N,N-dimethylacetobetaine, preferably N- (C ₈ -Ci ₈ )-acylaminopropyl-N,N-dimethylacetobetaine, (Ci2-Ci8)-alkyl-dimethyl- sulfopropylbetaine, amphosurfactants based on imidazoline (trade name: Miranol ^® , Steinapon ^® ), preferably the sodium salt of 1-(beta-carboxymethyloxyethyl)-1- (carboxymethyl)-2-laurylimidazolinium; amine oxide, e.g., (Ci2-Ci8)-alkyl- dimethylamine oxide, fatty acid amidoalkyldimethylamine oxide, and mixtures thereof.

In at least one embodiment, the core of the present invention comprises a betaine surfactant. Optionally, the betaine surfactant is selected from Cs- to Ci ₈ -alkylbetaines. In at least one embodiment, the betaine surfactant is selected from the group consisting of cocodimethylcarboxymethylbetaine, lauryldimethylcarboxymethylbetaine, lauryldimethylalphacarboxyethylbetaine, cetyldimethylcarboxymethylbetaine, oleyldimethylgammacarboxypropylbetaine and laurylbis(2-hydroxypropyl)alphacarboxyethylbetaine and combinations thereof. Optionally, the betaine surfactant is selected from Cs- to Ci ₈ -sulfobetaines. In at least one embodiment, the betaine surfactant is selected from the group consisting of cocodimethylsulfopropylbetaine, stearyldimethylsulfopropylbetaine, lauryldimethylsulfoethylbetaine, laurylbis(2-hydroxyethyl)sulfopropylbetaine, and combinations thereof. Optionally, the betaine surfactant is selected from carboxyl derivatives of imidazole, the Cs- to C-is-alkyldimethylammonium acetates, the Os- to Ci8 alkyldimethylcarbonylmethylammonium salts, and the Cs- to Cis-fatty acid alkylamidobetaines, and mixtures thereof. Optionally, the Cs- to Cis-fatty acid alkylamidobetaine is selected from coconut fatty acid amidopropylbetaine, N-coconut fatty acid amidoethyl-N-[2-(carboxymethoxy)ethyl]glycerol (CTFA name: cocoamphocarboxyglycinate), and mixtures thereof. A particularly preferred amphoteric or zwitterionic surfactant is cocam idopropyl betaine. Mixtures of any of the foregoing amphoteric or zwitterionic surfactants may also be suitable.

Preferred mixtures are those of cocam idopropyl betaine with further amphoteric or zwitterionic surfactants as described above. A preferred further amphoteric or zwitterionic surfactant is sodium cocoamphoacetate.

In at least one embodiment, the core comprises a surfactant system. In at least one embodiment, the surfactant system comprises at least one surfactant selected from the group consisting of lauryl sulfate, laureth sulfate, cocam idopropyl betaine, sodium cocoylglutamate, lauroamphoacetate, and mixtures thereof. In at least one embodiment, the surfactant system comprises sodium laureth sulfate, sodium lauryl sulfate, and optionally cocam idopropyl betaine. In at least one embodiment, the surfactant system comprises sodium laureth sulfate, potassium cocoylglutamate, and cocam idopropyl betaine.

In at least one embodiment, the core comprises an anionic surfactant. In at least one embodiment, the anionic surfactant is selected from the group consisting of (Cio-C2o)-alkyl and alkylene carboxylates, alkyl ether carboxylates, fatty alcohol sulfates, fatty alcohol ether sulfates, alkylamide sulfates and sulfonates, fatty acid alkylamide polyglycol ether sulfates, alkanesulfonates and hydroxyalkanesulfonates, olefinsulfonates, acyl esters of isethionates, alpha-sulfo fatty acid esters, alkylbenzenesulfonates, alkylphenol glycol ether sulfonates, sulfosuccinates, sulfosuccinic monoesters and diesters, fatty alcohol ether phosphates, protein/fatty acid condensation products, alkyl monoglyceride sulfates and sulfonates, alkylglyceride ether sulfonates, fatty acid methyltaurides, fatty acid sarcosinates, sulforicinoleates, acylglutamates, and mixtures thereof. The anionic surfactants (and their mixtures) can be used in the form of their water-soluble or water-dispersible salts, examples being the sodium, potassium, magnesium, ammonium, mono-, di-, and triethanolammonium, and analogous alkylammonium salts. In at least one embodiment, the anionic surfactant is the salt of an anionic surfactant comprising 12 to 14 carbon atoms. In at least one embodiment, the anionic surfactant is selected from the group consisting of sodium lauryl sulfate, sodium laureth sulfate, sodium tridecyl sulfate, sodium trideceth sulfate, sodium myristyl sulfate, sodium myreth sulfate, and mixtures thereof. Typical anionic surfactants for use in compositions of the invention include sodium oleyl succinate, ammonium lauryl sulphosuccinate, sodium lauryl sulphate, sodium lauryl ether sulphate, sodium lauryl ether sulphosuccinate, ammonium lauryl sulphate, ammonium lauryl ether sulphate, sodium dodecyl benzene sulphonate, triethanolamine dodecylbenzene sulphonate, sodium cocoyl isethionate, sodium lauryl isethionate, lauryl ether carboxylic acid and sodium N-lauryl sarcosinate. Preferred anionic surfactants are selected from sodium lauryl sulphate and sodium lauryl ether sulphate(n)EO, (where n is from 1 to 3); more preferably sodium lauryl ether sulphate(n)EO, (where n is from 1 to 3); most preferably sodium lauryl ether sulphate(n)EO where n=1.

The core may comprise fatty acyl isethionate, if present preferably at a level of from 1 to 10 wt.-%, more preferably from 2 to 8 wt.-%, most preferably from 2.5 to 7.5 wt.-%. A preferred fatty acyl isethionate product comprises fatty acyl isethionate surfactant at a level of from 40 to 80 wt.-% of the product, as well as free fatty acid and/or fatty acid salt at a level of from 15 to 50%. Preferably, greater than 20 wt.-% and less than 45 wt.-%, more preferably greater than 25 wt.-% and less than 45 wt.-% of the fatty acyl isethionate are of chain length greater than or equal to Cie; and greater than 50 wt.-%, preferably greater than 60 wt.-% of the free fatty acid/soap is of chain length Ci ₆ to C20. In addition, the product may contain isethionate salts, which are present typically at levels less than 5 wt.-%, and traces (less than 2 wt.-%) of other impurities.

Preferably, a mixture of aliphatic fatty acids is used for the preparation of commercial fatty acyl isethionate surfactants. The resulting fatty acyl isethionate surfactants (e.g., resulting from reaction of alkali metal isethionate and aliphatic fatty acid) preferably should have more than 20 wt.-%, preferably more than 25 wt.-%, but no more than 45 wt.-%, preferably 35% (on basis of fatty acyl isethionate reaction product) of fatty acyl group with 16 or greater carbon atoms to provide both excellent lather and mildness of the resulting fatty acyl isethionate product. These longer chain fatty acyl isethionate surfactants and fatty acids, i.e. fatty acyl group and fatty acid with 16 or more carbons, can typically form insoluble surfactant/fatty acid crystals in water at ambient temperatures.

The core comprising the quaternary ammonium compounds is further optionally coated with a polymeric shell. Suitable polymers that can be used for coating the core may be selected from polyurea, polyurethanes, epoxy, cross-linked silicone fluids, polydivinyl chloride, polyesters, polyamides, polyacrylates, polycarboxylates, and mixtures thereof.

In at least one embodiment, the polymeric shell is comprised of polyacrylates selected from polyacrylate formed from methylmethacrylate/dimethylaminomethyl methacrylate, polyacrylate formed from amine acrylate and/or methacrylate and strong acid, polyacrylate formed from carboxylic acid acrylate and/or methacrylate monomer and strong base, polyacrylate formed from an amine acrylate and/or methacrylate monomer and a carboxylic acid acrylate and/or carboxylic acid methacrylate monomer, and mixtures thereof.

In at least one embodiment, the polymeric shell is comprised of polyurea, polyurethane or epoxy, and mixtures thereof.

In at least one embodiment, the polymeric shell comprises of polyurea. In preferred embodiments, the polyurea comprises mixtures of poly-isocyanates and polyamine monomers. Examples of suitable polyisocyanates include 2,4- and

2.6-toluene diisocyanate (TDI), naphthalene diisocyanate, diphenyl methane diisocyanate, triphenyl methane-p,p'p"-trityl triisocyanate, polymethylene polyphenylene isocyanate, 2, 4, 4'-diphenylether triisocyanate, 3,3'-dimethyl-4,4'- diphenyl diisocyanate, 3,3'-dimethoxy-4,4'diphenyl diisocyanate, triphenylmethane 4,4', 4 triisocyanate, Dicyclohexylmethane 4,4'-diisocyanate, hexamethylene

1.6-diisocyanate, isophorone diisocyanate (IPDI), trimethyl-hexamethylene diisocyanate, trimethylene diisocyanate, propylene-1 ,2-diisocyanate, butylene 1,2-diisocyanate and mixtures thereof.

Examples of suitable polyamines include Aziridine PZ-33, Aziridine PZ-28, diethylene triamine (DETA), isophorone diamine (IPDA), hexamethylene diamine (HDA), Ethylene Diamine (EDA), Triethylenetetraamine (TETA), Tetraethylene Pentamine, 2,4,4'-Triaminodiphenylether, Bis(Hexamethylene) Triamine, Trimethylenedipiperidine (TMDP), Guanidine Carbonate (GUCA), Phenylene Diamine, Toluene Diamine, Pentamethylene Hexamine, 2,4-Diamino-6-Methyl-

1.3.5-Triazine, 1 ,2-Diaminocyclohexane, 4,4'-Diaminodiphenylmethane,

1.5-Diaminonaphthalene, Diamino Propane, Diaminobutane, Piperazine (PIP), Tetraethylenepentamine (TEPA), Aminoethylenepiperazine (AEP), Diethyltoluene diamine (DETDA), poly (propylene glycol) bis (2-aminopropyl ether) or [Jeffamine D-230], and 0,0'-bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-poly propylene glycol [Jeffamine ED 600], Dynasylan 1146,

Dynasylan DAMO-T, Silres HP2000, Silres HP 2020, and the like.

In at least one embodiment, the polymeric shell comprises of polyurethanes. In preferred embodiments the polyurethanes comprise of mixtures of poly-isocyanate and diol monomers. Examples of suitable poly-isocyanates include 2,4- and

2.6-toluene diisocyanate (TDI), naphthalene diisocyanate, diphenyl methane diisocyanate, triphenyl methane-p, p' p"-trityl triisocyanate, polymethylene polyphenylene isocyanate, 2,4,4'-diphenylether tri isocyanate, 3,3'-dimethyl-4,4'- diphenyl diisocyanate, 3,3'-dimethoxy-4,4'diphenyl diisocyanate, triphenylmethane 4,4', 4 triisocyanate, Dicyclohexylmethane 4,4'-diisocyanate, hexamethylene

1.6-diisocyanate, isophorone diisocyanate (IPDI), trimethyl-hexamethylene diisocyanate, trimethylene diisocyanate, propylene-1 ,2-diisocyanate, butylene 1 ,2-diisocyanate and mixtures thereof.

Examples of suitable diol monomers include Ethyleneglycol, diethylene glycol, propylene glycol, 1 ,4-butane diol, 1 ,4 hexane diol, dipropylene glycol, cyclohexyl 1 ,4 dimethanol, 1 ,8 octane diol and polyols such as poly (ethylene glycols), poly (propylene glycols), poly (tetramethylene glycols) and mixtures thereof. In at least one embodiment, the polymeric shell comprises of epoxy or epoxy resins prepared from cross-linking reactions of epoxy resin and polyamines. Suitable epoxy resins are selected from the group comprising of aromatic, aliphatic epoxy resin, cycloaliphatic resin and Novolac Epoxy Resins. Suitable examples of epoxy resin are diglycidyl ether of bisphenol A (e.g. Lapox B 11 , Lapox B47 and Lapox ARB-22), diglycidyl ethers of bisphenol F, diglycidyl ether of bisphenol F and tetraglycidyl-4,4'-diaminodiphenylmethane, dodecanol glycidyl ether, trimethylolpropane triglycidyl ether, epoxy phenol novolacs (EPN), epoxy cresol novolacs (ECN), diglycidyl ether of butane diol (Butyl dioldiglycidyl ether),

3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexane carboxylate, triglycidyl-p- aminophenol, N,N,N,N-tetraglycidyl-4,4-methylenebis benzylamine, 4-glycidyloxy- N, N-di-glycidyl aniline, 1.1.2.2-(p-hydroxyphenol) ethane based epoxy resin, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethyleneglycol diglycidyl ether, propylene glycol diglycidyl ether or glycerol polyglycidyl ether and the like.

Examples of suitable polyamines include, but are not limited to, Aziridine PZ-33, Aziridine PZ-28, diethylene triamine (DETA), isophorone diamine (IPDA), hexamethylene diamine (FIDA), Ethylene Diamine (EDA), Triethylenetetraamine (TETA), Tetraethylene Pentamine, 2,4,4'-Triaminodiphenylether, Bis(Hexamethylene) Triamine, T rimethylenedipiperidine (TMDP), Guanidine Carbonate (GUCA), Phenylene Diamine, Toluene Diamine, Pentamethylene Hexamine, , 2,4-Diamino-6-Methyl-1 ,3,5-Triazine, 1 ,2-Diaminocyclohexane, 4,4'-Diaminodiphenylmethane, 1 ,5-Diaminonaphthalene, , Diamino Propane, Diaminobutane, Piperazine (PIP), Tetraethylenepentamine (TEPA), Aminoethylenepiperazine (AEP), Diethyltoluene diamine (DETDA), poly (propylene glycol) bis (2-aminopropyl ether) or [Jeffamine D-230], and 0,0'-bis(2- aminopropyl) polypropylene glycol-block-polyethylene glycol-block-poly propylene glycol [Jeffamine ED 600], Dynasylan 1146, Dynasylan DAMO-T, Silres HP2000, Silres HP 2020, and the like. In preferred embodiments, the polymers maybe present in an amount ranging from 5 to 25 wt -%, more preferably from 10 to 20 wt -% and most preferably from 12 to 16 wt -% by weight of the total weight of the encapsulated product.

According to the present invention, the loading of the quaternary ammonium compounds with respect to the total composition of encapsulated product can vary from 10 to 60 wt.-%, preferably in the range from 20 to 50 wt.-% and most preferably in the range from 30 to 40 wt.-%.

Second Aspect

In a second aspect, the present invention relates to a method of preparing the encapsulated quaternary ammonium compounds according to the first aspect, comprising: i. blending at least one quaternary ammonium compound with at least one non-ionic surfactant and optionally at least one wax, ii. entrapping this blend in an inorganic carrier to form a core, and iii. optionally coating the core with a first monomer and then optionally with a second monomer to form an in-situ polymeric shell, wherein the method is solvent-free.

In at least one embodiment, the blend of the quaternary ammonium compound and the nonionic surfactant may be blended with at least one wax and/or at least one additional surfactant different from the nonionic surfactant. The blending of the quaternary ammonium compound and the nonionic surfactant with wax and/or additional surfactant is carried out in step (i) by melting the quaternary ammonium compound, nonionic surfactant and the wax and/or surfactant.

In at least one embodiment, for the addition of step (ii), the inorganic carrier is first heated to a temperature above the melting points of the wax and/or surfactant and then the blend of step (i) is added to the inorganic carrier, to form the core. In at least one embodiment, the step (iii) is carried out in 4-5 sub-steps wherein the core is first coated with a first monomer to form a uniform coating on the inorganic carrier and then subsequently a second monomer is added to react with the first monomer to form the polymeric shell. The addition of the second monomer may be conducted over a period of 3-6 hours. In certain preferred embodiments, the addition of the second monomer may be carried out under heating at 30 to 60°C.

In at least one embodiment, the step (iii) occurs for at least 3 hours, more preferably at least 4 hours, even more preferably at least 5 hours, most preferably at least 6 hours.

In at least one embodiment, the step (iii) occurs at at least 60°C, more preferably at least 50°C, even more preferably at least 40°C.

In at least one embodiment, the steps (ii) and (iii) occur with stirring or spraying under solvent-free conditions.

In a preferred embodiment, the encapsulated quaternary ammonium compounds of the present invention are manufactured by the method of the present invention.

The process of the present invention is completely solvent-free and thereby a more environment-friendly and scalable method that does not involve the use of organic solvents and hence, prevents the complications in processing arising due to their use.

The present invention also relates to encapsulated quaternary ammonium compounds obtained by the method of the present invention.

The encapsulated quaternary ammonium compounds of the present invention can, for example, be used in paint compositions. The invention further relates to the use of the encapsulated quaternary ammonium compounds of the present invention in paint compositions. Preferred components are described further below.

The encapsulated quaternary ammonium compounds described herein may be mixed with one or more further components to form stable paint compositions having long-lasting anti-algal benefit post-application.

In accordance with the present invention, the encapsulated quaternary ammonium compounds may be present from about 0.05 to 4 wt.-%, preferably in the range from 0.08 to 3 wt.-% and most preferably in the range from 0.1 to 0.5 wt.-% in the paint compositions, based on the total weight of the composition. For example, the paint composition of the invention comprises 0.05 wt.-%, 0.1 wt.-%, 0.2 wt.-%,

0.3 wt.-%, 0.4 wt.-%, 0.5 wt.-%, 1.0 wt.-%, 1.5 wt.-%, 2.0 wt.-%, 2.5 wt.-%,

3.0 wt.-%, 3.5 wt.-%, of the encapsulated quaternary ammonium compounds described herein, based on the total weight of the composition.

The paint composition of the present invention comprises one or more further components, which can be in an amount of at least 0.01% by weight, preferably at least 0.05% by weight, more preferably at least 0.1% by weight, even more preferably at least 0.5% by weight, such as 0.5 to 20% by weight of the composition. Preferably, the component is selected from the group consisting of antioxidants, thickeners, pH neutralizers, wetting agents, dispersing agents, defoaming agents, fillers, biocides, binders, extenders, coalescing agents, pigments, solubilizers, flow control assistants, stabilizers, preferably heat and/or high-temperature stabilizers, process stabilizers, and UV and/or light stabilizers, flame retardants, photoprotectants, deaerating agents, and the like.

As used herein, the term "pigment" refers preferably to compounds in powder form or platelet form which are insoluble substantially, preferably completely, in the medium surrounding them, such as in the coating composition of the invention, for example. Pigments differ from "fillers" preferably in their refractive index, which for pigments is > 1.7. Examples of suitable pigments are selected from the group consisting of organic and inorganic, color-imparting and extender pigments. Examples of suitable inorganic color-imparting pigments are white pigments such as zinc white, zinc sulfide, or lithopone; black pigments such as carbon black, iron manganese black, or spinel black; chromatic pigments such as chromium oxide, chromium oxide hydrate green, cobalt green or ultramarine green, cobalt blue, ultramarine blue, or manganese blue, ultramarine violet or cobalt violet and manganese violet, red iron oxide, cadmium sulfoselenide, molybdate red or ultramarine red; brown iron oxide, mixed brown, spinel phases and corundum phases, or chromium orange; or yellow iron oxide, nickel titanium yellow, chromium titanium yellow, cadmium sulfide, cadmium zinc sulfide, chromium yellow, or bismuth vanadate. Examples of suitable organic color-imparting pigments are monoazo pigments, disazo pigments, anthraquinone pigments, benzimidazole pigments, quinacridone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, dioxazine pigments, indanthrone pigments, isoindoline pigments, isoindolinone pigments, azomethine pigments, thioindigo pigments, metal complex pigments, perinone pigments, perylene pigments, phthalocyanine pigments, or aniline black. Preferred embodiments comprise, in particular, usually titanium dioxide, iron oxide pigment, and carbon black.

As used herein, the term "filler" refers preferably to a substance which is substantially insoluble, preferably completely insoluble, in the coating composition of the invention, and is used more particularly for increasing the volume. "Fillers" within the meaning of the present invention preferably differ from "pigments" in their refractive index, which for fillers is <1.7. Any customary filler known to the skilled person may be used in accord with the present invention. Examples of suitable fillers are kaolin, dolomite, calcite, chalk, calcium sulfate, barium sulfate, graphite, silicates such as magnesium silicates, more particularly corresponding phyllosilicates such as hectorite, bentonite, montmorillonite, talc and/or mica, silicas, especially fumed silicas, hydroxides such as aluminum hydroxide or magnesium hydroxide, or organic fillers such as textile fibers, cellulose fibers, polyethylene fibers, or polymer powders; for further details refer to Rompp Lexikon Lacke and Druckfarben, Georg Thieme Verlag, 1998, pages 250 ff. , "Fillers". Normally, in addition, corrosion inhibitors are used, such as silicates, orthophosphates, and polyphosphates. Only for special instances are colored surfacers produced, which support the intended hue for the topcoat system. The surfacers normally have various gray shades, which are produced by fractions of pigmentary carbon blacks and iron oxides (usually yellow iron oxide).

The paint compositions of the present invention may also comprise of dispersing agents. Exemplary dispersing agents include anionic polyelectrolyte dispersants such as maleic acid copolymers, acrylic acid copolymers including methacrylic acid copolymers, and carboxylic acids such as tartaric acid, succinic acid, citric acid, itaconic acid, mixtures thereof and other materials that will be familiar to persons having ordinary skill in the art. Exemplary surfactants include anionic, amphoteric and nonionic materials. There may be some overlap in nomenclature when certain dispersants or surfactants are identified in commercial literature. Suitable dispersants and surfactants are commercially available from a variety of suppliers including 3M, Air Products and Chemicals, Inc., Akzo Nobel, Ashland, BASF, Dow Chemical Co., E. I. DuPont de Nemours and Co., Elementis Specialties, Inc., Flarcros Chemicals, Rhodia and Solvay, such as the TAMOL.TM. series from Dow Chemical Co., nonyl and octyl phenol ethoxylates from Dow Chemical Co. (e.g., TRITON. TM. X-45, TRITON X-100, TRITON X-114, TRITON X-165, TRITON X-305 and TRITON X-405) and other suppliers (e.g., the T-DET N series from Flarcros Chemicals), alkyl phenol ethoxylate (APE) replacements from Dow Chemical Co., Elementis Specialties, Inc. and others, various members of the SURFYNOL.TM. series from Air Products and Chemicals, Inc. (e.g., SURFYNOL 104, SURFYNOL 104A, SURFYNOL 104BC, SURFYNOL 104DPM, SURFYNOL 104E, SURFYNOL 104H, SURFYNOL 104PA, SURFYNOL 104PG50,

SURFYNOL 104S, SURFYNOL 2502, SURFYNOL 420, SURFYNOL 440, SURFYNOL 465, SURFYNOL 485. SURFYNOL 485W, SURFYNOL 82, SURFYNOL CT-211, SURFYNOL CT-221, SURFYNOL OP-340, SURFYNOL PSA204, SURFYNOL PSA216, SURFYNOL PSA336, SURFYNOL SE and SURFYNOL SE-F), various fluorocarbon surfactants from 3M, E. I. DuPont de Nemours and Co. and other suppliers, and phosphate esters from Ashland, Rhodia and other suppliers. When a surfactant or dispersant is present, the base paint or stain may for example contain at least about 0.1 , at least about 0.5 or at least about 1 wt.% surfactants or dispersants, and up to about 10, up to about 5 or up to about 3 wt.% surfactants or dispersants based on the total composition weight.

The base paint or stain may contain a variety of other adjuvants that will be familiar to persons having ordinary skill in the art. Representative adjuvants are described in Koleske et al. , Paint and Coatings Industry, April, 2003, pages 12-86. Exemplary adjuvants and commercial examples of the same include anti-cratering agents; biocides, fungicides, mildewcides and preservatives; coalescing agents (e.g., those described in U.S. Pat. No. 8,110,624 B2 to Brandenburger et al.); curing indicators; heat stabilizers; leveling agents; light stabilizers (e.g., hindered amine light stabilizers such as TINUVIN™ 123-DWand TINUVIN 292 HP from Ciba Specialty Chemicals); optical brighteners; ultraviolet light absorbers (e.g., TINUVIN 234 and TINUVIN 1130 from Ciba Specialty Chemicals); wetting agents (e.g., BYK™ 346 and BYK 348 from Altana, PENTEX™ 99 from Rhodia and TROYSOL LAC™ from Troy corporation); waxes (e.g., AQUACER™ 593 from Altana, HYDROCER™ 303 from Shamrock Technologies, Inc. and MICHEM™ Emulsion 32535 from Michelman, Inc.); and the like. The types and amounts of these and other adjuvants typically will be empirically selected.

The paint compositions of the present invention may further comprise of solvents. Examples of solvents used as pigment dispersion media include, for example, water, aromatic hydrocarbon solvents such as toluene or xylene, aliphatic hydrocarbon solvents such as mineral spirits, alcohol solvents such as methanol or ethanol, ester solvents such as ethyl acetate, ketone solvents such as methyl ethyl ketone, and ether solvents such as ethylene glycol.

In at least one embodiment, the paint composition is aqueous and comprises of water as the solvent for pigment dispersion.

The invention is illustrated by the following examples without being limited thereby. EXAMPLES Examples 1 - 3 Entrapment of quaternary ammonium compounds (QAC) in inorganic carrier (Core, C)

The inorganic carrier was first introduced, and the temperature set above the temperature of melting point of wax/surfactant. The quaternary ammonium compound (QAC), and optionally, the water insoluble wax or water-soluble surfactant were melted and mixed and this blend was added drop wise to the inorganic carrier. This resulted in formation of the core (C) comprising the quaternary ammonium compound. The quantities of materials used are given in table 1 below.

Table 1

Examples 4 - 6 Encapsulation of entrapped quaternary ammonium compounds (Encapsulated Core, EC) The core, C, from the above examples was allowed to cool and then epoxy resin was added as a first monomer under stirring (150-300 rpm with overhead stirring device at RT). The stirring was continued for 1 hour to ensure uniform mixing of epoxy resin on inorganic carrier surface. Then polyamine was added dropwise as second monomer in four slots.

1 . First slot - After 1 hour mixing at RT, dropwise addition of 40 wt.-% polyamine was done in 5-10 min and stirring was continued at RT for 1 h. Then the temperature of the mixture was raised to 40°C.

2. Second slot - after 1 hour of heating, dropwise addition of 20 wt.-% polyamine was done in 5-10 min and stirring was further continued under heating for 1 h.

3. Third slot - dropwise addition of 20 wt.-% polyamine was done in 5-10 min and stirring was further continued under heating for 1 h.

4. Fourth slot - dropwise addition of remaining 20 wt.-% polyamine was done in 5-10 min and stirring was further continued under heating for further 1 h.

Then the heating was stopped and stirring continued till the temperature reached RT.

The encapsulation of the quaternary ammonium compound was analyzed using scanning electron microscope (SEM). The samples showed morphological differences when QAC is entrapped or encapsulated, i.e. between C and EC. The average particle size of formulation is measured by Malvern mastersizer-3000 particle size analyser. The d90 (pm) data is given against the respective examples in the table below.

The following table 2 gives the details of the quantities of materials used.

Table 2

Examples 7-12 Preparation of paint composition containing QAC

Standard water-based exterior paint formulations were prepared in a jacketed vertical vessel (high speed disperser with cowl disc setup) by adding ingredients listed in Table 3, keeping a continuous supply of cold water to avoid loss of water due to heat generation. The core ( C) and polymeric shell coated samples (EC) were added in grinding phase or let-down phase to achieve uniform dispersion in paint formulation. Table 3

* Nipacide DFX5 was used as standard comprising Diuron, Methyl benzimidazol-2-ylcarbamate, zinc oxide and 2-octyl-2H-isothiazol-3-one.

Example 13 Measurement of viscosity of the paint compositions

Viscosity measurement was carried out by Brookfield Viscometer KU-2.

Paint formulations were taken in the container 1/2 inch (20 mm) below the container lip. The formulation in the container was allowed to come to the room temperature and the container was placed directly on the viscometer base. Then pint-can adapter (KU1-74 and KU1-73) was placed in sample container and viscosity measured in KU. A difference of more than 15 KU between the initial and final values was considered to be an indicator of unstable paint formulation. Table 4 Viscosity data for paint compositions

^* Does not contain any anti-algal active

^# Sample showed heavy gelation and precipitation so viscosity could not be tested From the above table, it was observed that at accelerated storage conditions, the viscosity of blank paint decreased substantially resulting into a viscous composition whereas and paint compositions with QAC blended with the non-ionic surfactant showed comparatively less change in the viscosity. Samples having the optional polymeric shell also showed less change in viscosity (Example 9), however, the samples with unblended and non-encapsulated QAC (Example 12) showed higher viscosity implying that the leaching of QAC in the paint formulation (in-can storage) gets retarded by blending the QAC with a non-ionic surfactant and/or by further encapsulating with the polymeric shell.

Example 14 Antialgal performance of paint compositions

The encapsulated quaternary ammonium compound (QAC) samples were dosed in paint at specified dosages and tested for Dry Film Algal Challenge Test by Agar Plate Assay Method.

DRY-FILM PRESERVATION TEST METHOD USING ACCELERATED AGEING AGAR PLATE ASSAY

Preparation of Paint Batches: Paint batches were prepared as per Examples 7 to Example 12 by addition of the unblended, encapsulated, non-encapsulated or blank samples as per the decided dosage. For the Example 12, anti-algal test could not be carried out as the sample showed gelation and precipitation and was unstable due to the interaction of non-encapsulated QAC with the paint formulation.

Panel application: The paint batches with the samples from Examples 7 to 12 were thinned with water at a thinning ratio of 30% by volume. Two coats of the thinned samples were brush applied onto filter paper. One set of panels were tested as such and one set was tested after subjecting to leaching in water for 8 hours.

Dry-Film Preservation test: The panels were cut into required size and inoculated with algal cultures on a suitable agar plate. The algal plates were incubated at 25°C ± 2.5°C for 4 weeks under light illumination. After incubation, the filter paper was examined for the degree of algal surface contamination and the zone of inhibition was measured in mm.

INOCULA

Algae:

Nostoc muscorum Oscillatoria tenius Pleurococcus sp. Chlorella pyrenoidosa Trentepohlia odorata

OBSERVATIONS

Example 11 Blank showed heavy algal growth (>60% coverage) with no zone of inhibition under un-leached as well as leached conditions.

Example 7 showed light algal growth (10 - 30% coverage) under un-leached conditions and moderate algal growth (30 - 60% coverage) under leached conditions.

Example 10 showed moderate algal growth (30 - 60% coverage) under un-leached as well as leached conditions. Example 11 showed light algal growth (10 - 30% coverage) under un-leached conditions and moderate algal growth (30 - 60% coverage) under leached conditions.

Example 12 showed traces of algal growth (< 10% coverage) under un-leached conditions and moderate algal growth (30 - 60% coverage) under leached conditions.

The results of the Dry Film Algal Challenge Test are shown in Table 5 below.

Table 5

Note:

Thinning ratio: 30% by volume with water.

Key:

0 = No growth

1 = Traces of growth (<10% coverage)

2 = Light growth (10% - 30% coverage)

3 = Moderate growth (30% - 60% coverage)

4 = Heavy growth (60% - complete coverage) UL = Un-leached

L = Leached

CONCLUSION From the above study, it was observed that

Under un-leached conditions, sample of Example 8 did not show comparable performance to the standard, however, samples of Example 7, and Example 9 were comparable to the standard (Diuron) showing at least 70% inhibition of algal growth. Under leached conditions all samples showed comparable performance to the standard. Hence, it can be concluded that blending of the QAC with non-ionic surfactant and optionally encapsulating with polymeric shell was able to effectively control the algal growth over extended period of time.