The invention relates to an improved insectieidal water-in-oil (W/O) formulation with at least one insectieidal active substance and at least one burning salt and to the preparation of this formulation. The formulation according to the invention is particularly suitable for the treatment of suitable supports, in particular of paper supports, in an economical one-step process with the aid of conventional application processes. In addition, the present invention relates to insectieidal, smoulderable products which can be prepared by treating a support with the formulation according to the invention. A support treated with the formulation according to the invention shows in particular lower migration of the insectieidal active substance from the support into the environment (e.g. packaging material) prior to its intended use. US-A-2009/0163582 describes a water-in-oil (W/O) formulation in which a polyglycerol fatty acid ester or a sorbitan fatty acid ester is employed as emulsifier, a pesticide, for example a pyrethroid, as active substance and acetyl ester, a methyl ester, an acetyl tributyl citrate, a white mineral oil or a combination of these as the solvent. This formulation takes the form of an aerosol formulation for the end user.

WO-A-2007/131679 describes a paper impregnated with an insectieidal active substance. The paper here is prepared in a two-step process in which the paper is first pretreated with an aqueous 6% strength potassium nitrate solution and then dried, and then, in a further step, impregnated with active substance solution. WO-A-2007/131679 does not disclose any formulation in which the paper can be treated in a one-step process, in particular with an insectieidal active substance and the potassium nitrate salt.

WO-A-2011/092722 describes a paper impregnated with an insectieidal active substance, which paper, again, is prepared in a two-step process. Analogously to the process of WO-A-2007/131679, the paper is first treated with a potassium nitrate before being dried and then impregnated with the active substance.

The object of the present invention was to provide a formulation which is chemico-physically stable regarding an insectieidal active substance and a burning salt and which is therefore suitable in particular for the treatment of a support such as, for example, a paper. Preferably, the formulation is intended to make possible the treatment of the support in an economical and industrially robust one-step process. I n this one-step process, the required application weight of the formulation according to the invention is applied to the support in one process step so that the support will thereafter contain the functional formulation components such as, for example, the active substance and the burning salt in a sufficiently and homogeneously distributed manner. The formulations described in the prior art are not suitable for achieving this object. In particular, it is not possible with these known formulations to combine, in one formulation, an insectieidal active substance together with the burning salt required and to employ the combination for the purpose according to the invention. In particular, such formulations lack sufficient chemico-physical stability (to coalescence and creaming) and lack the rheological properties which are necessary for the required purpose of the invention and/or cannot be adapted simply to traditional machinery and processes for applying the formulation to a suitable support.

PCT/EP2013/05 920 which describes an oil-in-water (O/W) formulation and PCT/EP2013/059917 which describes a water-in-oil (W/O) formulation (both filed before but published after the filing date of this application) have provided some solutions to overcome the drawbacks of the prior art. However, the teachings provided in these patent applications do not address the additional problem how a volatile insecticidal active substance can be best retained on a support prior to its intended use within the context of the discussed formulations.

In light of the prior art, it was therefore an object of the present invention to substantially reduce the migration of the insecticidal active substance from the support into the environment (e.g. packaging material) prior to the intended use of the (insecticidal, smoulderable) support.

Surprisingly, it has now been found that the object is achieved by a water-in-oil (W/O) formulation comprising a) a surface -active emulsifying system which comprises

- a nonionic surface-active agent with an HLB value of in the range from about 3 to about

6,

- a further nonionic surface-active agent with a H LB value of in the range from about 11 to about 16,

- anionic surface-active agent selected from the group of carboxylic acids, phosphoric acid esters, sulfonic acids, sulfuric acid esters as well as in each indivual case their corresponding salts, b) at least one nonaqueous solvent selected from the group of Cetyloctanoate, Lauryllactate, Myristyllactate, Cetyllactate, Isopropylmyristate, Myri sty lmyri state, I sopropy lpalmitate , Isopropyladipate, Butylstearate, Decyloleate, Cholesterylisostearate, Glycerolmonostearate, Glyceroldistearate, Glyceroltristearate, C12-C15 Alkyllactate, C12-C13 Alkylcitrate and C12- Ci3 Alkyltartrate, at least one burning salt at least one insecticidal active substance having a vapour pressure of at least 0.00001 mPa

(at 25 °C), and e) water.

A W/O formulation generally describes a multiphase system in which an aqueous phase is dispersed in a continuous oil phase. The expression "oil" in this context is an umbrella term for water-insoluble liquids and solvents which in mixture with water or aqueous salt solutions bring about phase separation. Examples are aliphatic and aromatic solvents, vegetable and animal oils and their derivatives, fragrances or mixtures of these.

In experimental terms, one differentiates between a W/O and an O/W formulation by determining the specific conductivity. Aqueous salt solutions with a salt concentration of 5% by weight and higher will typically have a high specific conductivity in the mS/cm range, while the specific conductivity of aliphatic and aromatic solvents will typically be in the μ$/αοα range or below. As a consequence, a burning-salt-containing formulation will experimentally be classified as a W/O formulation when its specific conductivity amounts to less than 0.1 mS/cm. The conductivity of the present W/O formulation according to the invention is therefore preferably less than 0.1 mS/cm, measured at room temperature (20°C). A suitable surface-active emulsifying systems for the W/O formulation according to the invention comprises at least the following three components:

(Component 1): a nonionic surface-active agent with an H LB value of in the range from about 3 to about 6, and preferably from 3 to 6.

(Component 2): a nonionic surface-active agent with a HLB value of in the range from about 11 to about 16, and preferably from 1 1 to 16.

(Component 3): an anionic surface-active agent selected from the group of fatty alcohol ethersulfates, fatty alcohol sulfates, linear alkylbenzene sulfonates and oleic acid sulfonates.

The H LB value (HLB = hydrophilic-lipophilic balance) is an empiric scale defined by W. C. Griffin (J. Soc. Cosmetic Chemists, 1, 31 1 (1949)) which expresses the amphiphilic nature of emulsifying agents (in particular of nonionic surface-active agents). The lowest HLB values are assigned to the surface- active agents with the lowest hydrophilicity. Processes for determining the HLB are well known in the art, and any such process can be employed for determining the HLB. A description of the HLB system and processes for determining the HLB are described in "The HLB-System: a time saving guide to emulsifier selection", ICI Americas Inc., Wilmington, Delaware, 1976. Nonionic surface-active agents as Component 1 of the surface, active emulsifying system according to the W/O formulation of the invention are preferably selected from the group consisting of alkylphenol ethoxylates, alkanol ethoxylates, alkylamine ethoxylates, sorbitan esters (such as the Span series) and their ethoxylates (such as the Tween series), castor oil ethoxylates, ethylene oxide/propylene oxide block copolymers, alkanol/propylene oxide/ethylene oxide copolymers, polyglycerols and polyglycerol esters.

The hydrophilicity/lipophilicity balance (HLB) in nonionic surface-active agents may be adjusted by modifying the degree of ethoxylation.

Examples of nonionic surface-active agents as Compent 1 of the the surface, active emulsifying system according to the W/O formulation of the invention are (the order of the list is: brand name, HLB value, manufacturer); Brij 52 POE-(2)-cetyl alcohol; 5.3; Croda; Brij 72 POE-(2)-stearyl alcohol, 4.9, Croda; Brij 92V POE-(2)-oleyl alcohol, 4.9, Span 40 sorbitan monopalmitate, 6.7, Croda; Span 60 sorbitan monostearate, 4.7, Croda; Span 80 sorbitan monooleate, 4.3, Croda; Hostacerin SFO, 3-4, Clariant; AGNIQUE® FOES 90C-5, 4.9, Cognis; Genapol O 020, 5, Clariant; Atlox 4912, 5-6; Atlox 4914, 5-7, Emulsogen V 1816, 6, Clariant; Genapol PF 20 P. 4, Clariant; Genapol PF 40, 6, Clariant; Genapol 2822, 6. Clariant; Genapol 3970, 3, Clariant; Agrimer AL 25. 3-5. ISP; Agrimer VA-3, 4-7. ISP; Hostacerin DGI, 5, Clariant; GW 1250 (HLB 5), 5, Evonik. Most preferred is Span 80 sorbitan monooleate.

The nonionic surface-active agents as Component 2 of the surface, active emulsifying system according to the W/O formulation of the invention are selected from the group consisting of alkylphenol ethoxylates, alkanol ethoxylates, alkylamine ethoxylates, sorbitan esters and their ethoxylates, castor oil ethoxylates, ethylene oxide/propylene oxide block copolymers, alkanol/propylene oxide/ethylene oxide copolymers, polyglycerols, polyglycerol esters, or an emulsifying system selected from the group consisting of alkylsulphonates, arylsulphonates, alkylarylsulphonates, aryl ether sulphonates, ligno sulphonates , alkyl sulphates, alkyl ether sulphates, sulphosuccinates, aliphatic and aromatic phosphate esters, alkoxylated phosphate esters, alkylcarboxylates and polycarboxylates; in each case as salts of polyvalent cations. Examples of nonionic surface-active agents as Component 2 of the surface, active emulsifying system according to the W/O formulation of the invention are (order of listing: brand name, HLB value, manufacturer): Arkopal N 100, 13, Clariant; Arkopal N 150, 15. Clariant; Brij 58 POE-(20)-cetyl alcohol, 15.7, Croda; Brij 76 POE-(10)-stearyl alcohol, 12.4, Croda; Brij 96V POE-(10)-oleyl alcohol, 1 2.4. Croda; Brij 98V POE-(20)-oleyl alcohol, 15.3, Croda; Lubrol 17A17 POE-(i7)-oleyi alcohol, 14.9, Croda; Synperonic LI 1 POE-(l l)-lauryl alcohol, 15. Croda; Tween 20 POE-(20)-sorbitan monolaurate 16.7; Tween 21 POE-(4)-sorbitan monolaurate, 13.3; Tween 40 POE-(20)-sorbitan monopalmitate, 15.6; Tween 60 POE-(20)-sorbitan monostearate, 14.9; Tween 65 POE-(20)-sorbitan tristearate, 10.5; Tween 80 POE-(20)-sorbitan monooleate, 15; Tween 85 POE-(20)-sorbitan trioleate, 11 ; Cremophor RH 40 polyoxyl 40 hydrogenated castor oil, 14-16, BASF; Cremophor RH 60 PEG-60 hydrogenated castor oil, 15-17, BASF; Atlox 4913, 11-12; Emulsogen V 1816-2, 12, Clariant; Genapol V 4829, 14, Clariant; Emulsogen V 2436, 11, Clariant; Emulsogen 3510, 11, Clariant. Most preferred is Tween 80 POE-(20)- sorbitan monooleate.

In an even more preferred embodiment of the invention at least two different nonionic surface-active agents with a HLB value of in the range from about 11 to about 16 are used as Component 2 of the surface, active emulsifying system. Preferably Tween 80 POE-(20)-sorbitan monooleate and Cremophor RH 40 polyoxyl 40 hydrogenated castor oil are used in combination.

The anionic surface-active agents as Component 3 of the surface, active emulsifying system according to the W/O formulation of the invention are selected from the group consisting of carboxylic acids, phosphoric acid esters, sulfonic acids, sulfuric acid esters as well as in each indivual case their corresponding salts. The anionic surface-active agents are preferably present in the form of salts with monovalent cations.

Anionic surface-active agents consisting of carboxylic acids (and their salts) are for example alkanoic acids (and alkanoates), ester carboxylic acids (e.g. alkyl succinates), ether carboxylic acids, and the like.

Anionic surface-active agents consisting of sulfonic acids (and their salts) are for example isethionates (e.g. acyl isethionates); alkyl sulfonates such as ammonium lauryl sulfate, sodium lauryl sulfate ( SOS. sodium dodecyl sulfate); alkyl ether sulfates such as sodium laureth sulphate (lauryl ether sulfate (SLES)), sodium myreth sulfate; alkylaryl sulfonates, sulfosuccinates (e.g. monoesters and diesters of sulfosuccinate), and the like

Anionic surface-active agents consisting of sulfuric acid (and their salts) are for example alkyl ether sulfates, alkyl sulfates, and the like.

In another embodiment of the invention, anionic surface-active agents consisting of sulfonic acids and their salts are preferably used as Components 3 of the surface-active emulsifying system according to the W/O formulation of the invention. Even more preferred anionic surface-active agents are selected from the group of linear and branched primary and secondary alkyl sulfates and alkyl ether sulfates. Especially preferred are alkyl ether sulfates such as e.g. SLES known e.g. under the brand name Agnique SLES 227®.

In general, the W/O formulation comprises from 1 to 8 % by weight, preferably from 3 to 6 % by weight of Component 1 of the surface-active emulsifying system according to the W/O formulation of the invention. The W/O formulation further comprises from 1 to 5 % by weight, preferably from 2 to 4 % by weight of Component 2 of the surface-active emulsifying system according to the W/O formulation of the invention. The W/O formulation further comprises from 1 to 5 % by weight, preferably from 1 to 3 % by weight of Component 3 of the surface-active emulsifying system according to the W/O formulation of the invention. Nonaqueous solvents which can be used for the present invention are selected from the group of Cetyloctanoate, Lauryllactate, Myristyllactate, Cetyllactate, Isopropylmyri state (IPM), Myri sty lmyri state, Isopropylpalmitate, Isopropyladipate, Butylstearate, Decyloleate, Cholesterylisostearate, Glycerolmonostearate, Glyceroldistearate, Glyceroltristearate, C12-C15 Alkyllactate, C12-C13 Alkylcitrate and C12-C13 Alkyltartrate. In a particular preferred embodiment of the invention Isopropylmyristate (IPM) is used as a non-aqueous solvent. According to the invention, the W/O formulation preferably comprises from 5 to 75% by weight, preferably from 15 to 55% by weight, more preferably from 15 to 30% by weight of at least one nonaqueous solvent as component of the W/O formulation according to the invention. A further component of the formulation according to the invention is at least one burning salt. Burning salts allow supports which are treated with the formulation according to the invention to be controlled after igniting and subsequently extinguishing the flame and to smoulder uniformly. Therefore, the burning salt is capable of ensuring the combustibility of the treated support in respect of the rate and completeness of combustion without allowing spontaneous ignition. A burning salt is preferably selected from the group of nitrate salts (for example potassium nitrate, chromium nitrate, iron nitrate, copper nitrate, sodium nitrate). Potassium nitrate is preferably employed as the burning salt.

According to the invention, the W/O formulation preferably comprises from 6 to 25% by weight, preferably from 8 to 15% by weight, of at least one burning salt as component of the W/O formulation according to the invention.

The at least one insecticidal active substance according to the invention has a vapour pressure of at least 0.00001 mPa (at 25°C), more preferably of at least 0.0001 mPa (at 25°C). In a preferred embodiment, the at least one insecticidal active substance is selected from the group of esbiothrin, lambda- cyhalothrin, d-allethrin, S-bioallethrin, prallethrin, pyrethrum and an insecticide comprising a polyfluorobenzyl (preferably a tetrafluorobenzyl or pentafluorobenzyl and more preferably a tetraflurobenzyl) moiety. Within this enumeration the insecticide comprising a polyfluorobenzyl moiety is preferably selected from the group of Transfluthrin, Metofluthrin, Momfluorothrin, Meperfluthrin, Dimefluthrin, Fenfluthrin, Profluthrin, Tefluthrin and Heptafluthrin (more preferably from Transfluthrin, Metofluthrin and Momfluorothrin, even more preferably from Transfuthrin and Metofuthrin and most preferably from Transfluthrin).

In another even more preferred embodiment of the invention, the at least one insecticidal active substance, preferably a hydrophobic insecticidal active substance is selected from the group of esbiothrin, lambda- cyhalothrin, d-allethrin, S-bioallethrin, prallethrin, metofluthrin, pyrethrum and/or transfluthrin. Transfluthrin is preferred. The active substances, which are here referred to by the "common name", are known and described for example in the pesticide manual ("The Pesticide Manual" 15th Ed., British Crop Protection Council 2011) or can be found on the internet (for example http://www.alanwood.net/pesticides)

According to the invention, the W/O formulation preferably comprises from 0.1 to 10% by weight, preferably from 1 to 5% by weight, of at least one insecticide as component of the W/O formulation according to the invention.

A person skilled in the art is aware that also more than one insecticidal active substances can be used for the formulation according to the invention.

The present W/O formulation comprises water as additional component. The W/O formulation according to the invention preferably comprises from 20 to 83% by weight, more preferably from 35 to 60% by weight, of water.

In a preferred embodiment of the present invention, the W/O formulation according to the invention furthermore preferably comprises at least one colorant and/or at least one fragrance. Preferably, the formulation according to the invention comprises at least one colorant and at least one fragrance. Colorants which can be employed are inorganic pigments, for example iron oxide, titanium oxide, Prussion Blue, organic pigments and dyes such as triphenylmethanes, diphenylmethanes, oxazines, xanthenes, iminonaphthoquinones, azomethines and anthraquinones, such as, for example, Oil Yellow #101, Oil Yellow #103, Oil Pink #312, Oil Red, Oil Green BG, Oil Blue BOS, Oil Blue #603, Oil Black BY, Oil Black BS, Oil Black T-505 (Orient agaku ogyo), Victoria Pure Blue BOH (Hodogaya Kagaku), Patent Pure Blue (Sumitomo Mikuni Kagaku), Cyrstal Violet (CI 4255 ) Methyl Violet (CI 42535), Ethyl Violet, Rhodamin B (CI 145170B), Malchit Green (CI 142000). Methylene Blue (CI 52015), Brilliant Blue, Methyl Green, Erythrocin B, Basic Fuchsin, m-Cresol Purple, auramin, 4-p- diethylaminophenyliminaphthoquinone, leucobasis dyes and primary or secondary acrylamine dyes such as, for example, triphenylamine, diphenylamine, o-chloroaniline, 1 ,23 ,-triphenylganidine, naphthylamine, diaminodiphenylmethane, ρ,ρ-bis-dimethylaminodiphenylamine, 1 ,2-dianilinoethylene, p,p',p"-tris-dimethylaminotriphenylmethane, p,p'-bis-dimethylaminodiphenylmethylimine, ρ,ρ,ρ"- triamino-o-methyltriphenylmethane, p,p'-bis-dimethylaminodiphenyl-4-anilinonaphthylmethane, ρ,ρ',ρ"- triaminotriphenylmethane and the like.

It is preferred to employ anionic, cationic or basic colorants such as, for example, xanthene dyes Cera von Fast Rhodamine B 400% (DixonChew) and Sanolin Rhodamin B02 (Clariant), the substantive dyestuff Levacell Violett BB fl. 40% (Lanxess), the azo dyestuff Bayscript Magenta LB fl. (Lanxess), Ceracryl Magenta (DixonChew), Astra Red Violett 3RC liq. (Lanxess), Astra Phloxin G (Lanxess) and Cartazine Violet 4EK liq. (Clariant). It is especially preferred to use anionic colorants such as, for example, the xanthene dyes Cera von Fast Rhodamine B 400% (DixonChew) and Sanolin Rhodamine B02 (Clariant), the substantive dyestuff Levacell Violett BB fl. 40% (Lanxess) and the azo dyestuff Bayscript Magenta LB fl. (Lanxess).

Depending on the solubility of the colorants, further surface-active substances are employed in accordance with the invention so as to dissolve the colorants. If, for example, a triaminotriphenylmethane is employed, the colorant is dissolved using water and a surface-active substance, preferably at elevated temperatures (up to 70°C), before it is added to the formulation according to the invention. A suitable surface-active substance is, for example, a nonionic surface-active agent of ethoxylated alcohol (as described further above). Natural fragrances can be selected for example from the group consisting of lavender, musk, civet, ambergris, castereum and similar fragrances: ajowan oil, almond oil, ambrette seed absolute, angelica root oil, anisole, basil oil, bay oil, benzoin resinoid, essence of bergamot, birch oil, rosewood oil, ferula oil, cajeput oil, cananga oil, capsicum oil, caraway oil, cardamom oil, carrot seed oil, cassia oil, cedar wood oil, celery seed oil, cinnamon bark oil, citronella oil, clary sage oil, clove oil, cognac oil, coriander oil, oil of cubebs, camphor oil, dill oil, tarragon oil, eucalyptus oil, fennel oil sweet, calbanum resinoid, garlic oil, geranium oil, ginger oil, grapefruit oil, hop oil, hyacinth absolute, jasmine absolute, juniper berry oil, labdanum resinoid, lavender oil, bay leaf oil, lemon oil, lemon grass oil, lavage oil, mace oil, tangerine oil, Nfisoma absolute, myrrh absolute, mustard oil, narcissus absolute, neroli oil, nutmeg oil, oak moss absolute, olibanum resinoid, onion oil, opoponax resinoid, orange oil, orange flower oil, iris concrete, pepper oil, peppermint oil, balsam of Peru, petitgrain oil, pine needle oil, rose absolute, rose oil, rosemary oil, sandalwood oil, sage oil, curly-mint oil, styrax oil, thyme oil, tolu balsam, tonka bean absolute, tuberose absolute, oil of turpentine, vanilla pod absolute, vetiver oil, violet leaf absolute, ylang-ylang oil and similar plant oils and the like and their mixtures.

Synthetic fragrances which may be added to the formulation according to the invention are: pinene, limonene and similar hydrocarbons, 3 ,3 ,5 -trimethylcy clohexanol, linalool, geraniol, nerol, citronellol, menthol, borneol, borneylmethoxycyclohexanol, benzyl alcohol, anisyl alcohol, cinnamyl alcohol, β- phenylethyl alcohol, cis-3-hexanol, terpineol and similar alcohols, anethols, musk xylene, isoeugenol, methyleugenol and similar phenols; amylcinnamaldehyde, anisaldehyde, n-butyraldehyde, cuminaldehyde, cyclamenaldehyde, decylaldehyde, isobutyraldehyde, hexylaldehyde, heptylaldehyde, n- nonylaldehyde nonadienol, citral, citronellal, hydroxy citronellal, benzaldehyde, methylnonyl acetaldehyde, cinnamaldehyde, dodecanol, hexylcinnamaldehyde, undecanal, heliotropin, vanillin, ethylvanillin and similar aldehydes, methyl amyl ketone, methyl β-naphthyl ketone, methyl nonyl ketone, musk ketone, diacetyl, acetylpropionyl, acetylbutyryl, carvone, methone, camphor, acetophenone, p-methylacetophenone, ionone, methylionone and similar ketones; amyl butyrolactone, diphenyl oxide, methyl phenylglycidate, nonylacetone, coumarin, cineol, ethyl methylphenylglycidate and similar lactones or oxides, methylformate, isopropyl formate, linalyl formate, ethyl acetate, octyl acetate, methyl acetate, benzyl acetate, cinnamyl acetate, butyl propionate, isoamyl acetate, isopropyl isobutyrate, geranyl isovalerate, allyl capronate, butyl heptylate, octyl caprylate, methyl heptinecarboxylate, methyl octinecarboxylate, isoamyl caprylate, methyl laurate, ethyl myristate, methyl myristate, ethyl benzoate, benzyl benzoate, methyl carbinylphenylacetate, isobutyl phenylacetate, methyl cinnamate, styracin, spice OM 2044 (from IFF Inc.), methyl salicylate, ethyl anisate, methyl anthranilate, ethyl pyruvate, ethyl butylbutyrate, benzyl propionate, butyl acetate, butyl butyrate, p-tert- butylcyclohexyl acetate, cedryl acetate, citronellyl acetate, citronellyl formate, p-cresyl acetate, ethyl butyrate, ethyl caproate, ethyl cinnamate, ethyl phenylacetate, ethylene brassylate, geranyl acetate, geranyl formate, isoamyl salicylate, isoamyl valerate, isobornyl acetate, linalyl acetate, methyl anthranilate, methyl dihydroj asmonate, nonyl acetate, B-phenylethyl acetate, trichloromethylenephenylcarbinyl acetate, terpinyl acetate, vetiveryl acetate and similar esters. These fragrances can be used individually, or at least two of these can be used as a mixture with one another. In addition to the fragrance, the formulation according to the invention may, if appropriate, additionally contain the additives conventionally used in the fragrance industry, such as Patchouli oil or similar volatilization-inhibitory agents such as eugenol or similar viscosity -regulating agents.

The formulations according to the invention may also contain deodorizing agents such as, for example, lauryl methacrylate, geranyl crotonate, acetophenone myristate, p-methylacetophenone benzaldehyde, benzyl acetate, benzyl propionate, amylcinnamaldehyde, anisaldehyde, diphenyl oxide, methyl benzoate, ethyl benzoate, methyl phenyl acetate, ethyl phenyl acetate, neolin, safrol and the like.

The fragrances are preferably already a component of the nonaqueous solvent.

In general, the W/O formulation preferably comprises from 1 to 75% by weight, more preferably from 2 to 55% by weight, of a fragrance, even more preferably in an amount of from 5 to 15% by weight.

As a further preferred embodiment of the invention, the W/O formulation preferably comprises from 0.01 to 5% by weight, more preferably from 0.01 to 1% by weight, of a colorant. All percentages by weight which refer to the W/O formulation of the above-described components give not more than 100% in total.

I desired, the W/O formulation according to the invention furthermore comprises additives or adjuvants, preferably antifreeze agents, bittering agents, stabilizers, antifoam agents, wetters, antifoams and preservatives. Examples of suitable antifreeze agents are ethylene glycol, monopropylene glycol, glycerol, hexylene glycol, 1 -methoxy-2-propanol, cyclohexanol, in particular monopropylene glycol. Bittering agents which are suitable are in particular aroma oils, preferably peppermint oil, eucalyptus oil, bitter almond oil, menthol, fruit aroma substances, preferably aroma substances of lemons, oranges, citron, grapefruit or mixtures of these, and/or denatonium benzoate. Stabilizers which may optionally be added to the formulation are acids, preferably organic acids such as dodecylbenzenesulphonic acid, acetic acid, propionic acid or citric acid, in particular citric acid, and antioxidants such as butylhydroxytoluene (BHT), butylhydroxyanisol (BHA), in particular butylhydroxytoluene. Preferred antifoam agents and defoamers are silicone-based, especially preferred are an aqueous emulsion of dialkylpolysiloxanes, commercially available as Rhodorsil®; 426R from Rhodia Chimie France, Wacker SE series from Wacker, Germany, and a mixture of dialkylpolysiloxanes as an oil, commercially available as Rhodorsil®; 416 from Rhodia Chimie, France, Wacker 5184 or Wacker SL from Wacker, Germany.

The formulations according to the invention optionally also comprise further functional additives which effect the combustion properties or other properties of supports which are treated with the formulation according to the invention. Examples of such additives which may be mentioned are phosphate salts (such as, for example, sodium phosphates, monoammonium phosphates), organic acids (for example trisodium citrate, tripotassium citrate, sodium acetate, sodium tartrate, succinic acid, malonic acid and the like) and waxes. Further examples of such additives are mineral inorganic substances such as titanium dioxide, calcium carbonate, phyllosilicates such as kaolin, and organic fillers such as microcrystalline cellulose.

A further subject matter of the invention relates to the use of a formulation according to the invention for treating a support.

According to the invention "treating" refers to a process in which a support is brought into contact with the formulation. A suitable treatment method is impregnation, for example by spraying the support with the formulation according to the invention, followed by drying, for example in the air, or immersing the support in the formulation according to the invention, followed by drying, for example in the air. Other suitable impregnation processes are impregnation by means of a pipette. A further suitable and preferred treatment process which is particularly suitable is to print the support with the formulation according to the invention.

To print the support with the formulation, it is preferred to employ established application processes or coating facilities for continuous operation. Suitable printing processes and corresponding facilities are known for example from the graphics industry (direct and indirect printing processes) and from the paper industry (coating and impregnation processes). Other known facilities/pro ces ses are the blade- coating press, the film press, the size press, the curtain coating process and others.

Especially preferred are gravure processes, where the formulation according to the invention is applied directly from the rotating engraved cylinder to the support.

It has emerged that the present application is particularly suitable for being applied homogeneously to a support by means of a gravure process. Here, the formulations according to the invention remain physically stable and can be adapted readily to the selected gravure process in respect of the rheological properties (in particular viscosity and wetting properties). In the context of the present invention, the expression "physically stable" means that in a relevant time scale for the application of the formulation in a one-step coating process, in particular by means of a gravure process, no significant or macroscopic phase separation of the water phase and the oil phase, or creaming, takes place.

Under certain circumstances, it may be necessary to adapt the viscosity of the formulation to the coating process so as to avoid undesired side-effects caused by the process (such as, for example, inhomogeneous film splitting and misting, which may result in inhomogenities in the coating). I n this respect, the viscosity properties are preferably controlled via altering the weight fractions of the surface- active emulsifying system and/or via altering the composition of the surface-active emulsifying system and/or via modifying the proportions of the aqueous phase relative to the continuous "oil phase".

It has emerged that, when using a traditional gravure process and the preferred paper support defined hereinbelow, a Bingham viscosity of the W/O formulation according to the invention of between 20 and 200, preferably 30 to 150, mPa-s at 20°C is advantageous. The determination of the Bingham viscosity is based on measuring the shear stress at an increasing shear

-1

rate. The resulting shear stress values [Pa] are plotted versus the shear rate [s ]. The Bingham viscosity at higher shear rates is derived as the slope of the regression line.

The viscosity is measured at a temperature of 20°C using a rotary viscometer using measuring systems of the cylinder type (also referred to as double gap systems) standardized as specified in DIN EN ISO 321 , whose shear rate can be adjusted in a defined manner, for example from Haake, Bohlin, Mettler, Contraves and others. The viscometer should make possible measurements in a shear rate range of from 0.1 to 1200 s ¹ .

An advantage of the W/O formulations according to the invention is that the Bingham viscosity can be adjusted without employing polymeric thickeners and that, therefore, a very good and homogeneous transfer of the formulation from the engraved cylinder to the support can be ensured, even with increased production speed. Formulation residues which have dried on the engraved cylinder can be removed readily with water or with customary aqueous cleaners, in contrast to formulations with polymeric thickeners.

Supports which are suitable in accordance with the invention are in particular solid combustible materials such as cellulose materials, textile materials, plastic materials and the like. Cellulose-based supports are, for example, paper, board, wood, wood chippings, wood chips or sawdust, rice husks, maize cob spindles (preferably without kernels), pecan nut shells and peanut shells. Thin particle board is also suitable as the support. A suitable cellulose-based support is described, for example, in German patent application DE 43 223 76 Al, the disclosure of which is hereby included by reference.

Supports made of textile materials are, for example, synthetic polyester or nylon fibres or natural fibres such as cotton, viscose, a linen-viscose mixture or a mixture of synthetic and natural fibres such as cellulose-polyester (synthetic paper) or cotton-polyester. Other examples are wool feltine and Trevira satin.

Supports made of polymer materials are, for example, polycarbonates, polyesters, polyamides and polyterephthalate s .

Especially preferred within the scope of the present invention is the use of a cellulose-based support, in particular a paper support.

In principle, no special limitations are imposed on the paper support used here, as long as it is generally suitable for taking up at least one insecticidal active substance in question and, after igniting and extinguishing the paper support, releasing the at least one insecticidal active substance without essentially decomposing it. However, it has emerged that paper supports with a paper weight of preferably from 25 to 300 g/m ² , in particular 2 to 270 g/m ² , especially preferably 25 to 250 g/m ² , very especially preferably 25 to 230 g/m ² , further very especially preferably 25 to 215 g/m ² , specifically 25 to 200 g/m ² , are especially suited to the purpose according to the invention.

Furthermore, it is preferred for the thickness of the paper support to be in a range of from 0.05 to 0.50 mm, especially preferably 0.07 to 0.40 mm, very especially preferably 0.08 to 0.35, furthermore very especially preferably between 0.08 and 0.25 mm, specifically 0.08 to 0.20 mm.

Suitable supports and processes of treating the supports are likewise described in the laid-open specification WO2007/131679A2.

Another subject matter of the present invention relates to the use of the water-in-oil formulation according to the invention for treating a support. The "treating" is preferably effected by printing the support. Even more preferably, the printing of the support is effected via a gravure process, preferably by a "one-step" printing process.

A further subject of the present invention relates to a support which has been treated with a water-in-oil formulation according to the invention. It is preferred for the application weight of the (W/O) formulation on the support (preferably the paper support) to be in a range of from 5 to 30 ml/m ² , especially preferably from 12 to 22 ml/in ² and very especially preferably from 15 to 20 ml/m ² .

The content of insecticidal active substance on a support according to the invention, in particular a paper support, is preferably between 0.05 to 5.0 % by weight, more preferably between 0.1 to 2.5 % by weight and even more preferably between 0.2 und 1.5 % by weight.

It is preferred for the burning salt content of the treated support (preferably a paper support) to be in the range of from 0.1 to 6% by weight, especially preferably from 1 to 5% by weight and very especially preferably from 1.5 to 3% by weight.

In general, the support according to the invention (in particular a paper support) preferably comprises from 0.01 to 10% by weight, more preferably from 0.05 to 5% by weight, especially preferably from 0.15 to 2.5% by weight, of the above-described surface-active emulsifier system.

It is preferred for the treated support to comprise a fragrance which has a positive effect on the odour of the smoulderable end product before and after smouldering.

It is preferred for the fragrance content of the treated support (preferably a paper support) to be in the range of from 0.1 to 10% by weight, especially preferably from 0.5 to 5% by weight and very especially preferably from 0.8 to 3% by weight.

It is preferred for the nonaqueous solvent content of the treated support (preferably a paper support) to be in the range of from 0.5 to 5% by weight, especially preferably from 2 to 3.5% by weight.

A further subject matter of the invention relates to a process of preparing the water-in -oil formulation according to the invention, comprising the following steps: a) dissolving at least one burning salt in water, b) dissolving at least one nonaqueous solvent selected from the group of Cetyloctanoate, Lauryllactate, Myristyllactate, Cetyllactate, Isopropylmyristate, Myristylmyri state, Isopropylpalmitate, Isopropyladipate, Butylstearate, Decyloleate, Cholesterylisostearate, Glycerolmonostearate, Glyceroldistearate, Glyceroltristearate, G2-C15 Alkyllactate, C12-C13 Alkylcitrate and G2-C13 Alkyltartrate, in at least one insecticidal active substance having a vapour pressure of at least 0.00001 mPa (at 25 °C), preferably at least one insecticidal active substance selected from the group of esbiothrin, lambda-cyhalothrin, d-allethrin, S-bioallethrin, prallethrin, metofluthrin, pyrethrum and trans fluthrin, and in a surface-active emulsifying system which comprises

- a nonionic surface-active agent with an H I .15 value of in the range from about 3 to about 6,

- a further nonionic surface-active agent with a HLB value of in the range from about 1 1 to about 16,

- an anionic surface-active agent selected from the group of carboxylic acids, phosphoric acid esters, sulfonic acids, sulfuric acid esters as well as in each indivual case their salts, c) mixing of the solution of step b) with the solution of step a).

I f optionally further water-soluble formulation components (such as, for example, cationic or anionic colorants, further additives) are to become a component of the W/O formulation, they are added to the water in step a), together with the burning salt.

If optionally further water-insoluble liquid formulation components (such as, for example, fragrances, further additives) are to become a component of the W/O formulation, then they are admixed to the nonaqueous solvent before performing step b).

Mixing in step c) to give a W/O formulation according to the invention is performed by homogenizing via simple stirring or via a conventional emulsifying process.

A further particular preferred embodiment of the invention relates to a Water-in-oil formulation comprising

- from 1 to 5%, preferably from 2 to 4% by weight trans fluthrin (preferably technical grade),

- from 5 to 15%, preferably 8 to 10% by weight a fragrance, preferably Spice OM 2044,

- from 15 to 30%, preferably from 15 to 20% by weight Isopropylmyristate,

- from 3 to 6%, preferably from 5 to 6% by weight Span 80 sorbitan monooleate,

- from 0.5 to 3%, preferably from 1 .5 to 2.5% by weight Tween 80 POE-(20)-sorbitan monooleate,

- from 1 to 5%, preferably from 2 to 3 % by weight as sodium lauryl ether sulphate, preferably Agnique® SLES 227

- from 0.5 to 3%, preferably 1 to 2% by weight Cremophor RH 40 polyoxyl 40 hydrogenated castor oil, - from 8 to 15%, preferably from 12 to 13% by weight potassium nitrate,

- from 0.01 to 1%, preferably 0.1 to 1% by weight Ceravon Fast Rhodamine B.

- from 0.01 to 0.1% by weight Denatoniumbenzoat,

- from 35 to 60%, preferably from 45 to 50% by weight water, therein all percentages by weight which refer to the W/O formulation of the above-described components give not more than 100% in total.

A further subject matter of the present invention relates to an insecticidal, smoulderable product comprising an above-described support and the components of the above-described water-in -oil formulation according to the invention. The herein discussed nonaqueous solvent does not evaporate from the support during the preparation and is present in the final insecticidal, smoulderable product.

In a further preferred embodiment the insecticidal, smoulderable product according to the invention comprises a) a support, (preferably in the range of from 80 to 90% by weight) b) at surface-active emulsifying system which comprises - a nonionic surface-active agent with an HLB value of in the range from about 3 to about 6 (preferably in the range of from 0.05 to 1.0% by weight)

- a further nonionic surface-active agent with a HLB value of in the range from about 11 to about 16 (preferably in the range of from 0.05 to 0.8%) by weight),

- an anionic surface-active agent selected from the group of carboxylic acids, phosphoric acid esters, sulfonic acids, sulfuric acid esters as well as in each indivual case their corresponding salts (preferably in the range of from 0.05 to 0.7%> by weight), c) at least one burning salt (preferably in the range of from 1.5 to 3% by weight), d) at least one insecticidal active substance having a vapour pressure of at least 0.00001 mPa (at 25°C), preferably at least one insecticidal active substance selected from the group of esbiothrin, lambda-cyhalothrin, d-allethrin, S-bioallethrin, prallethrin, metofluthrin, pyrethrum and trans fluthr in (preferably in the range of from 0.2 to 1.5% by weight), e) at least one nonaqueous solvent selected from the group of Cetyloctanoate, Lauryllactate, Myristyllactate, Cetyllactate, Isopropylmyristate, Myristylmyristate, Isopropylpalmitate, Isopropyladipate, Butylstearate, Decyloleate, Cholesterylisostearate, Glycerolmonostearate, Glyceroldistearate, Glyceroltristearate, C12-C15 Alkyllactate, C12-C13 Alkylcitrate and C12-C13 Alkyltartrate (preferably in the range of from 2 to 3.5% by weight), and f) water (preferably in the range of from 2 to 5% by weight), and therein all indicated percentages by weight which refer to the insecticidal, smoulderable product of the above -described components give not more than 100% in total.

A further subject matter of the invention is a process of preparing an insecticidal smoulderable product, characterized in that a support is treated with a water-in-oil formulation according to the invention. Preferably, the preparation is carried out by printing the support with the water-in-oil formulation according to the invention. More preferably, printing of the support is performed via a gravure process, preferably by a "one-step" printing process.

Examp!es:

Example 1 : Description of the preparation of the formulations according to the invention

In accordance with the above-specified preparation protocol (see page 13), the following formulations according to the invention were made up with trans fluthrin (Fl A = formulation A according to PCT/EP2013/059917 as a comparison; Fl B = formulation B according to the invention):

Table 1 : Specification of the formulation components in per cent by weight, based on the respective W/O formulations.

Mixing of the formulations as specified in preparation step c) (see page 13) was carried out by simple stirring with the aid of a conventional magnetic stirrer.

Example 2: Description of the preparation of the insecticidal smoulderable product according to the invention

To prepare the insecticidal papers, the active substance formulations described in Example 1 (Fl A, Fl B), were applied homogeneously to the entire surface of the support at a defined application weight, using a gravure process. The support employed was the offset paper Tauro Offset 90 gm (Robert Horn Group, size: lengh ~8 cm and width ~6 cm). The formulations were applied in one step using the printability tester PhantomQD™ Proofer (HARPER Graphics GmbH) and the screen roll 306 140 100 20.0C (theoretical scoop volume approximately 31 cmVm ² and engraving angle of 60 degrees, HARPER Graphics GmbH). The formulation was transferred directly from the engraved cylinder to a paper strip at constant pressure and an application weight of approximately 16 g/m ² . The printed paper strips were dried in ambient air for at least one hour and then tested for printing quality (via visual assessment of the homogeneity of the inking of the paper) and the smouldering behaviour. The smouldering behaviour was checked by folding the coated paper strips lengthwise, igniting them on one side, blowing out the resulting flame and placing them onto a fireproof support so that it can smoulder away completely. The degree to which the paper strip smoulders away or carbonizes is considered to be a measure for the smouldering behaviour of the coated paper strip.

Table 2: Quality of the coating and smouldering behaviour of the insecticidal smoulderable products prepared in accordance with Example 2.

Example 3: Description of the packaging of insecticidal smoulderable products prepared in accordance with Example 2. 12 paper strips from Products A and B produced according to example 2 (with printed cover sheets in between the paper strips) were sealed into plane unprinted CPP laminate (12Mic PET/Adhesive/25mic Nat CPP, from Abvee Industries Limited) packaging films with conventional packaging machine equipment.

Example 4: Migration charateristics of transfluthrin from insecticidal smoulderable products. Migration of transfluthrin from the insecticidal smoulderable (Product A and Product B in accordance with Example 2) within the packaging material was measured with GC/'FID. Product B surprisingly shows 30% less migration of transfluthrin into the packaging material after 2 weeks storage at 54°C in comparison to Product A. This example demonstrates the improved properties of the W/O formulation and the insecticidal smoulderable products according to the invention.