WO1997022246A1

WO1997022246A1 - Solubilizing biocides using anhydrous 'onium' compounds as solvent

Info

Publication number: WO1997022246A1
Application number: PCT/NZ1996/000143
Authority: WO
Inventors: Nigel Paul Maynard
Original assignee: Nigel Paul Maynard
Priority date: 1995-12-20
Filing date: 1996-12-17
Publication date: 1997-06-26
Also published as: AU1043497A; EP0917425A1; AU732685B2

Abstract

A solution that has been prepared by heating at least one biocide in anhydrous 'onium' compound(s) (e.g. quaternary ammonium, etc.) or a polar aprotic solvent solution thereof. Such method is applicable to metal organic complexes (e.g. copper 8-hydroxyquinoline chelates) or to organic biocides that in the absence of extreme conditions of pH are of low solubility in common solvents. Such a solution once established can then be treated in a number of ways, e.g. to create an aqueous phase supported micro emulsion or micro suspension.

Description

SOLUBILIZING BIOCIDES USING ANHYDROUS "ONIUM" COMPOUNDS AS SOLVENT

TECHNICAL FIELD

The present invention relates to solubilising techniques for chemical moieties including not only the procedures themselves but the thus solubilised moieties and preparations thereof.

As used herein the term "chemical moieties^,, includes within its ambit any metal organic complex or organic entity.

The present invention relate to solubilising techniques allowing the achievement of solutions of a chemical moiety or moieties which may then be dispersed in common solvents (including water) to produce micro-emulsions, macro-emulsions or suspensions, such original solutions being non-aqueous and aprotic.

The solubilised moiety may be part of a process other than the formulation of a finished product, for example, where the 'onium' solubilised produce may be used in another manufacturing process as a step in another synthesis or in the application of the moiety to other non fluid substrates. This is especially so for biocidal applications.

As used herein therefore the term "metal organic complex or organic moiety" encompasses within its scope any metal organic complex to be solubilised for a purpose and any organic moiety (whether containing one or more hetero atoms) to be solubilised also having some purpose (or mixtures of both) and such may include but are not restricted to metal organic complexes include those of (alone or in admixture) aluminium, bismuth, boron, cadmium, calcium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, thorium, titanium, tungsten, uranium, vanadium and zinc. and/or organic moieties include (alone or in admixture) benzimidazoles, IPBC, Chlorthalonil, substitute triazoles, synthetic pyrethroids, anmelmintics such as Mebendazole, Albendazole, Fenbendazole, Flubendazole, Oxfendazole and Thiabendazole, growth promotant/coccidiostats such as the ionophore antibiotics typified by Lasalocid, Monensin and Tylosin, antibiotics such as Diclazuril, Cationomycin, Virginiamycin, Maduramycin, Narasin, Salinomycin, Halofiiginone, Phenothiazines and Pyrimidines. Other metal and organic moieties abound (for example, selenium, or, for example, a whole range of different ecto-or endo-parsitic compositions of an organic form or of a metal organic complex form

The term "polar aprotic solvent" or "highly polar aprotic solvent" includes but is not limited to glycol diethers (eg. tetraethylene glycol dimethyl ether), n-alkyl pyrrolidones (eg. n-octyl pyrrolidone), lactones (eg. butyrolactone), ketones (eg. acetophenone or cyclohexanone), lactams (eg. caprolactam), morpholines (eg. n-methyl morpholine or the N oxide thereof), substituted ureas (eg. tetramethyl urea), ring compounds containing oxygen and/or nitrogen groups (eg. dioxane, dioxane, tetrahydrofuran, pyridine, alkyl carbonates or cychc carbonates, imidazolines). The group can be extended to include sulphoxides, amides, organic phosphates and where suited esters.

As used herein the term "onium" compound in respect of anhydrous compounds refers to an anhydrous compound selected from quaternary ammonium, phosphonium, arsonium or similar compounds, ternary sulphonium compounds and may include amine or phosphine oxides and sulphoxides which can be viewed as quaternary compounds. The preferred "onium" compound or compounds is or are selected from quaternary ammonium compounds or amine or phosphine oxides.

As used herein the term "common solvent" includes water and/or common organic solvents some of which are referred hereinafter specifically by reference to carbendazim and oxine copper. Others include those referred to in the various scenarios hereinafter described (particularly with reference to scenario 1).

As used herein the term "low solubility" refers to any solubility of a kind below where the use ofthe present invention provides an advantage by way of delivery, stability or otherwise over the use of such "common solvents".

DISCLOSURE OF THE INVENTION

In a first aspect the invention consists in a solution (solid or liquid) of at least one biocide which is a "metal organic complex or an organic moiety" which, at least in the absence of extreme conditions of pH (high or low), is of low solubility or insoluble in "common solvents", said solution having being prepared by dissolution of the biocide(s) with heating in

(i) an anhydrous "onium" compound or anhydrous "onium" compounds, or

(ii) a polar aprotic solvent solution of an anhydrous "onium" compound or anhydrous "onium" compounds.

Preferably said "metal organic complex or an organic moiety" was prepared prior to the presence of the anhydrous "onium" compound or compounds.

In some cases said "metal organic complex or an organic moiety" was prepared subsequent to the presence of the anhydrous "onium" compound or compounds.

In still other instances said "metal organic complex or an organic moiety" was prepared at least in part during the presence of the anhydrous "onium" compound or compounds.

Preferably no aprotic solvent (as in (ii)) is present during such dissolution.

Preferably at least one biocide is an organic moiety of low solubility in common solvents in the absence of extremes of pH.

Preferably at least one said biocide is a benzimidazole.

Preferably at least one said biocide is Carbendazim.

In some embodiments at least one said biocide is a metal chelate.

Preferably said metal chelate is a chelated biocidal metal and the chelating agent is selected from 8-hydroxyquinoline or analogues thereof, hydroxy aromatic acids or analogues thereof, nicotinic or picolinic acid or analogues thereof, or mixtures thereof.

Preferably said metal chelate is a chelate with 8-hydroxyquinolinolate ligands or is a mixed chelate of which at least one ligand is an 8-hydroxyquinolinolate.

Preferably said onium compound is selected from the group consisting of quaternary ammonium, quaternary sulphonium and quaternary phosphonium compounds and amine, phosphine oxide and sulphoxide equivalents of the parent compound.

Preferably said onium compound is anhydrous and free from protic solvents.

Preferably in some embodiments the at least one said biocide includes an atom of at least one of the group consisting of atoms of aluminium, bismuth, boron, cadmium, calcium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, thorium, titanium, tungsten, uranium, vanadium and zinc.

Preferably biocide includes an atom selected from atoms of copper, zinc and aluminium.

Preferably said atom is that of copper.

In some cases the resulting solution has been diluted by a polar aprotic solvent to reduce viscosity.

In some embodiments wherein said onium compound(s) is or are biocidal.

In some instances a coloured metal chelate is included, eg; is bismuth 8-hydroxyquinolinolate .

Preferably said polar aprotic solvent(s) is selected from the group consisting of glycol diethers, n-alkyl pyrroUdones, lactones, ketones, lactams, moφholines, substituted ureas, ring compounds containing oxygen and/or nitrogen groups, alkyl carbonates, cyclic carbonates, imidazolines, suplhoxides, amides, orgamc phosphates and, where suited, esters.

Preferably the solution induces more than one biocide.

Preferably where the solution includes more than one biocide, each biocide has been dissolved with heating in the or an anhydrous "onium" compound or compounds (whether separately dissolved and subsequently blended or dissolved together).

Preferably one or more biocide(s) is a synthetic pyrethroid, an organochlorine, an organophosphate, a triazole, a phenol, an isothiazolinone, an imidazole, a thiocyanate, a carbamate, a benzimidazole, a thalonitrile, a n-nitroso-hydroxyamine metal sale, a sulphone and/or a thiazole.

Preferably one biocide is a metal chelate and the other biocide or biocides are added, if desired or necessary, after the dissolution with heating of the metal chelate in the anhydrous onium compound.

Preferably the solution is liquid at ambient temperatures.

In some instances the hydrotrope/lipotrope balance [HLB] has been altered subsequent to the biocide(s) dissolution, eg; the solution has had added at least one surfactant.

In some preferred embodiments there is subsequently also an aqueous phase.

Preferably the composition is in the form of a micro suspension or micro emulsion.

In a further aspect the present invention consists in a method of preparing a biocidal solution (solid or liquid) which comprises the steps of (i) for a single biocidal compound, or (ii) for a mixture of biocidal compounds, or (iii) for separate biocidal compounds, dissolving each biocidal compound in an anhydrous onium compound (or compounds) [optionally including a highly polar aprotic solvent] with heating,

[and in the case of (iii) blending the separate solutions], and optionally, diluting [before or after any blending] the solution(s) with a polar aprotic solvent to reduce viscosity.

In still a further aspect the invention consists in a method of solubilizing a biocide ("low solubility biocide") which is a metal organic complex or an organic moiety which, at least in the absence of extreme conditions of pH (high or low), is of low solubility or insoluble in "common solvents", said method comprising i) dissolving with heating the low solubility biocide (with or without any other biocidal compound) in an anhydrous "onium" compound or compounds, and ii) optionally, reducing the viscosity by dilution with an aprotic solvent, and iii) optionally, before or after optional step (ii) [if any step (ii)] blending the solution of step (i) or derived from step (i) with another biocide or a solution of another biocide.

Preferably said heating is to a temperature or temperatures of from 50 °C to 170°C.

Preferably said "metal organic complex or an organic moiety" was prepared prior to the presence of the anhydrous "onium" compound or compounds. In some cases said "metal organic complex or an organic moiety" was prepared subsequent to the presence of the anhydrous "onium" compound or compounds.

Preferably no aprotic solvent (as in (ii)) is present during such dissolution.

Preferably in some embodiments said at least one biocide is an organic moiety of low solubility in common solvents in the absence of extremes of pH.

Preferably at least one said biocide is a benzimidazole.

Preferably at least one said biocide is Carbendazim.

In other embodiments the at least one said biocide is a metal chelate.

Preferably said onium compound is anhydrous and free from protic solvents.

In some embodiments the at least one said biocide includes an atom of at least one ofthe group consisting of atoms of aluminium, bismuth, boron, cadmium, calcium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, thorium, titanium, tungsten, uranium, vanadium and zinc.

Preferably said biocide includes an atom selected from atoms of copper, zinc and aluminium.

Preferably said atom is that of copper.

In some embodiments the resulting solution has been diluted by a polar aprotic solvent to reduce viscosity.

In some instances said onium compound(s) is or are biocidal.

In some embodiments a coloured metal chelate is included, eg; bismuth 8- hydroxyquinolinolate.

Preferably said polar aprotic solvent(s) is selected from the group consisting of glycol diethers, n-alkyl pyrrolidones, lactones, ketones, lactams, morpholines, substituted ureas, ring compounds containing oxygen and/or nitrogen groups, alkyl carbonates, cyclic carbonates, imidazolines, suplhoxides, amides, organic phosphates and, where suited, esters.

In some embodiments the composition includes more than one biocide.

Preferably the solution includes more than one biocide, each biocide having been dissolved with heating in the or an anhydrous "onium" compound or compounds (whether separately dissolved and subsequently blended or dissolved together).

In some embodiments one biocide is a metal chelate and the other biocide or biocides are added, if desired or necessary, after the dissolution with heating of tiie metal chelate in the anhydrous onium compound.

Preferably the resulting solution is liquid at ambient temperatures.

In some embodiments the hydrotrope/lipotrope balance [HLB] is altered subsequent to d e biocide(s) dissolution, ie; the resulting solution is altered to include at least one surfactant.

Preferably the solution is modified so that there is also an aqueous phase.

Preferably a micro suspension or micro emulsion results.

Preferably where there is at least two biocides and at least one of the biocides is a metal chelate, the composition has the metal chelate dissolved without the need to resort to use of phenols, strong acids or metal soaps, in an anhydrous aprotic compound chosen from quaternary compounds of nitrogen and phosphorus, tertiary compounds, sulphur and amine, phosphine oxide or sulphoxide equivalent.

Preferably the metal chelate is the 8-hydroxyquinoline chelate of copper and the dissolution has required heating.

In another aspect the invention consists in a method of fixing a biocidal metal species or organic species in an environment subject to aqueous leeching, said method comprising applying into said environment the biocidal species whilst solubilised in an onium compound (with or without dilution widi an aprotic diluent).

Preferably the biocidal species is applied as a solution or composition of the present invention.

In still another aspect the invention conists in a biocidally treated matrix or animal, said matrix or animal being an environment treated by a solution or composition ofthe present invention or by a metiiod of the present invention.

The present invention also includes the animal pour on application of a solution or composition of the present invention.

The present invention also consists in the biocidal product of the method of the present invention.

The method may include dilution of the resulting solution to reduce viscosity, by inclusion of polar aprotic solvents such as glycol diethers eg. tetraethylene glycol dimethyl etiier; n-alkyl pyrrolidones eg. n-octyl pyrrolidone; lactones eg. butyrolactone; ketones eg. acetophenone or cyclohexanone; lactams eg. caprolactam; moφholines eg. n- methyl moφholine or the N oxide thereof; substituted ureas eg. tetramethyl urea; ring compounds containing oxygen and/or nitrogen groups eg. dioxane, dioxane, tetrahydrofuran, pyridine, alkyl carbonates or cyclic carbonates, imidazolines. The group can be extended to include sulphoxides, amides, organic phosphates and where suited esters.

The method preferably includes addition of additional surfactants when compatibility with specific solvents is required.

The method preferably includes addition of surfactants where the formation of specific macro or micro emulsions are desired, including betaines, phosphate esters, and nonionics such as amine or alcohol ethoxylates or propoxylates, and glycol esters.

The method preferably includes addition of co-biocides including insecticides or co-fungicides when broader spectrum of biocidal performance is required. These can be chosen from insecticides eg. synthetic pyrethroids such as Permithrin, Deltamethrin, Cypermethrin, etc; organochlorine insecticides such as Lindane; organophosphates such as Chloφyriphos; or fungicides eg. triazoles such as Hexaconazole [(RS)-2-(2,4- dichlorophyenyl)- 1-( IH- 1,2,4-triazol- l-yl)hexan-2ol], although Azanconazole, Tebuconazole, Cyprocanazole, Flusilazole and Propiconazole, may be used depending on the biological problem to be controlled; phenols such as pentachlorophenol; isothiazolinones such as 4,5-dichloro-2-(n-octyl0-4-isothiazolinone; imidazoles; thiocyanates such as methylene bis thiocyanate; carbamates such as 3-iodo-2-propyl- butyl-carbamate; benzimidazoles such as Carbendazim; thalonitriles such as Chlorothalonil; n-nifroso-hydroxyamine metal salts such as bis-(n- cyclohexyldiazeniumdioxy)-copper; sulphones such as diiodo-para-tolyl-sulphone; and thiazoles such as 2-thiocyantomemylti io-benzothiazole. These are preferably added upon completion of the dissolution of the metal complex as some may be sensitive to heat.

In yet a further aspect the present invention consists in a method of fixing a biocidal metal species or organic species in an environment subject to aqueous leeching, said method comprising applying into said environment the biocidal species whilst, as in the case of a metal biocidal species, solubilised as a metal organic complex in an onium compound (with or without dilution with an aprotic diluent) [and irrespective of whether or not it is applied as a solution or as a slurry or emulsion].

In some forms of the present invention said slurry or emulsion is at least a partial aqueous system.

Preferably the arrangement is substantially as hereinafter described.

In some forms of the present invention the environment can be a pour on zone of an animal or a zone of skin for transdermal penetration of an animal or human.

In still other aspects the environment can be on and/or in wood.

Any appropriate environment is envisaged.

In yet a further aspect the present invention consists in a biocidally treated matrix or animal, said matrix or animal being an environment treated by a method in accordance with the present invention.

DETAILED DESCRIPTION

The present invention allows solubilisation of biocides which are otherwise insoluble, or have low solubility in common solvents, without recourse to extreme conditions of pH (high or low). Examples include (as a metal organic complex) Oxine Copper (as hereinafter defined) and (as an organic moiety) Carbendazim. These are typically soluble to the extent following;

Solubility (parts per million)

Solvent Ethanol Water Aliphatic Aromatic Glycol Pyridine This Hydrocarbon Hydrocarbon Ether technology

Carbendazim 300 8 0.5 36 50 > 100,000

Oxine Copper Insoluble 0.22 Slight > 150,000

Any suitable solubilisation regime also allows addition by mixing or blending of co-biocides. The co-biocides are not critical with respect to solubility ie. they may be soluble in known solvents. They are however preferably also solubilised by addition to the formulations of this technology and maybe used in combination of two or more. Scenario 1. To create a 'solution' of biocide, where the solution can be solid or liquid.

Biocide Step 1

I

Dissolve in anhydrous 'onium' compound with heating Step 2

I

To give a clear concentrated solution Step 3

1

Dilute as required with a highly polar aprotic solvent to reduce viscosity Step 4

1. The biocide is inherently insoluble in standard solvents, which include those typically used for solubilisation including water, aliphatic and aromatic hydrocarbons, chlorinated solvents, ethers, esters, lactams, ketones, alcohols, carbonates, nitrohydrocarbons, amides, and other solvents and variations of these known to those versed in the art of biocide formulation. As examples, Copper 8- Hydroxyquinolinolate (Oxine Copper) and Carbendazim are only soluble to any extent in acids. This technology enables these compounds to be solubilised easily at neutral pH.

2. The onium compound may be selected from quaternary Ammonium, Phosphonium, Arsonium or similar compounds, ternary Sulphonium compounds and may include amine or phosphine oxides which can be viewed as quaternary compounds. The preferred onium compound is selected from quaternary ammonium compounds, amine or phosphine oxides.

3. The temperature of dissolution will depend on the biocide selected. For example, copper 8-hydroxyquinolinolate requires heating for approximately one hour 140° Celsius, whereas Carbendazim requires only fifteen minutes at 100° Celsius.

4. Steps 2, 3 and 4 may be combined.

Scenario 2. To create a 'solution' combination of biocides, where the solution can be solid or liquid.

Biocide a) Biocide b) Step 1

1 I

Dissolve in anhydrous Dissolve in anhydrous Step 2

'onium' compound with 'onium' compound with heating heating

1 1

To give a clear To give a clear Step 3 concentrated solution concentrated solution

Diluted as required with a Step 4 highly polar aprotic solvent Specifications of scenario 1 apply. Steps 3 and 4 may be exchanged.

Scenario 3. To create a 'solution' of biocides, where the solution can be solid or liquid.

Biocide 1

Biocide 2 Step 1

Biocide n I Dissolved in anhydrous

'onium' compound with Step 2 heating 1 To give a clear Step 3 concentrated solution i Dilute as required with a highly polar aprotic Step 4 solvent to reduce viscosity

1 Conditions as previously described.

2 Steps 2, 3 and 4 may be combined.

Scenario 4. To create a 'solution' of biocide(s), where the solution can be solid or liquid and whereafter additional co-biocides may be added.

Biocide(s) Step 1

I Dissolved in anhydrous

'onium' compound with Step 2 heating I To give a clear Step 3 concentrated solution

1 Dilute as required with a highly polar aprotic Step 4 solvent to reduce viscosity

1 Dissolve co-biocide(s) in solution of principal Step 5 biocide 1 Conditions are previously stated.

2 Steps 2, 3 and 4 may be combined.

METALLIC SPECIES SOLUBILISATION

Organo-metallic complexes are formed in a number of ways between multivalent metal ions and organic ligands. They are highly valued in industry, agriculture and medicine for uses including biocides, catalysts, feed supplements and pigments. Many metal complexes are water soluble and may readily be formulated for end use by appropriate techniques. A large number, however, are not readily soluble in water and may only be made so by use of severe chemical conditions.

An example of insoluble metal complexes are those formed between multivalent metal ions and 8-hydroxyquinoline, or the mixed chelates of 8-hydroxyquinoline and aryl hydroxy acids (for example salicylic acid). Although soluble in very acid conditions, these complexes precipitate from aqueous solutions as the pH rises to 3 or 4. In order to solubilise the complexes they must be reacted with strong acids (organic or inorganic) to form further complexes which themselves are soluble, and then the acid concentration must be maintained at a sufficient strength to prevent precipitation, or they must be maintained at very low pH conditions such that the complex is solubilised. Extremes of this may however separate the metals from the complex.

Many complexes also have very low solubility in organic solvents necessitating the use again of strong organic acids to solubilise them. For solubilisation in organic solvents other techniques may be used including formation of partial esters with alkylated phenols or mixed chelate esters with metal soaps such as Nickel 2-ethyl hexanoate.

There are significant disadvantages in having to use the above techniques to solubilise these complexes. They include; high cost of the adjuvants and the high corrosivity of the solution formed.

There would be many advantages to be gained from being able to form soluble complexes of the above compounds which eliminated the high corrosivity whilst also minimising the cost of additional components. The benefits would be even greater where those additional components which were necessary for solubilisation contributed directly to the performance ofthe formulation produced.

It has surprisingly been found that the above complexes can be solubilised by dissolution at elevated temperature in anhydrous tetra - substituted nitrogen and phosphorous compounds and trisubstituted sulphur compounds, for example, quaternary ammonium, phosphonium and tertiary sulphonium compounds. This process which although relatively simple is clearly novel since those working in many fields of use of the complexes have continued to utilise traditional formulating techniques.

To illustrate the current status of formulation or solubilisation of metal complexes, the following will refer specifically to their use in biocidal formulations and more specifically to wood preparation, as an example, The many advantages over current technology can be demonstrated when one refers to a number of patents wherein metals and or metal complexes are formulated, sometimes with the addition of tetra- substituted nitrogen compounds as supplementary biocides to produce, for example, wood preservative compositions.

US Patent 157184 to Chapman Chemical Company, teaches that metal complexes can be solubilised by reaction with a strong organic acid preferably dodecyl benzene sulphonic acid. The patent claims a range of metals and where the formulation is principally used as a biocide, the ability to use a number of co-biocides. Typically the solvents used are protic ie. water, alcohols or glycols and the formulation may be prepared entirely in die presence of water, that is the presence of water does not hinder the method of solubilisation. The disadvantage of this formulation has previously been described as necessitating use of acidic materials which can be corrosive.

NZ Patent No. 199565 and NZ Patent No. 2005360 to Domtar of Canada and Kenogard of Sweden respectively, teaches that preservative metal compounds can be conformulated with quaternary ammonium compounds, where the metals are retained in solution by the addition of large amounts of ammonia or aliphatic amines. Although in these methods the pH is at the other extreme ie. a high pH, corrosion is still a problem and any person dealing with the formulation must also contend with noxious fumes from the ammonia or amines. The latter compounds are a significant cost because they are lost from the formulation by volatilisation after treatment of the substrate and therefore provide little long term value. They are also a threat to the environment since they are classified as toxic gases.

When comparing the use of metals and quaternary ammonium compounds as wood preservatives it has been reported that the loadings used for ammonia based preservatives must be higher than for example an acid metal preservative such as copper chrome arsenate because leaching of die metal is higher with die alkaline preservative. This also poses additional deficiencies for this type of formulation because loss of metal to the environment may detract from product performance and also constitutes an additional environmental threat. NZ Patent No. 1975250 to Kenogard teaches a variation on the organic acid solubilised metal complex in that a second chelating ligand is introduced to the 8- hydroxyquinoline complex, namely the hydroxy substituted aromatic acids. This gives some advantages over the pure metal hydroxyquinoline complexes in that the biological performance was much greater and the cost was somewhat reduced. The enhanced performance of mixed chelates has previously been reported by Gershon and co-workers, published in 1962. The need for strong acids in the formulating technique however, still remains with its inherent disadvantages. French patent 7133717 teaches the synthesis of mixed chelates of metals particularly those using 8-hydroxyquinoline and tiiat the mixed metal complexes are insoluble in water or typical organic solvents.

In some situations it can be important that the metal complex be solubilised in aliphatic or aromatic solvents. This may apply where the complex is to be used as a biocide applied, for example, in an aliphatic solvent system or where the complex may be used in some catalytic process. UK Patent GB 2152816 describes a method wherein the above metal complexes are reacted witii both strong organic acids and an alkyl phenol to give a product which produces relatively stable solutions with these solvents. Again, strong acids and additional expensive adjuvants are essential for the success of the technique.

Metal complexes of 8-hydroxyquinoline have been proven to be good biocides, a fact well documented in the literature, with extensive details of performance against fungi and bacteria listed in US Patent No. 4766113 granted to Chapman in 1988. These however have continued to stress the need for strong acids to solubilise the metal complex.

NZ Patent No. 246976 and NZ Patent No. 243460 both to Hickson International, document efforts made to overcome some ofthe inherent problems of using quaternary ammonium compounds in conjunction with preservative metals. These remove to some extent the difficulties inherent in the Domtar and Kenogard patents in that relatively neutral solutions can be formed by using water soluble complexing agents for the metal (simple organic hydroxy acids and phosphonic acids are included as examples), which remained soluble in the aqueous solvent system used ie. in the presence of water. Although improvements have been realised, the cost of adjuvants has not been negated and there is therefore room for further improvement.

NZ Patent 215943 to Kop-Coat, Inc. discloses wood preservative compositions comprising a synergistic combination of DDMAC (didecyldimethyl ammonium chloride) of formula

and IPBC (3-iodo-2-propynyl butyl carbamate) of formula

I-C*C-CH--0-C-NH-(CH- -CH,

II o

where DDMAC as an aqueous solution is used to emulsify an organic solvent solution of IPBC.

The present invention provides the prospect of the same synergism or synergism from the other biocidal moieties being used in combination biocidally but without the need for a separate organic solvent dissolution of one active moiety prior to the presence ofthe other active moiety (where it is an "onium" compound) and indeed well prior to any deliberate inclusion of an aqueous phase.

One objective ofthe present invention to solubilise otherwise very insoluble metal complexes of, as an example of 8-hydroxyquinoline, hydroxy aromatic acids and their mixed complexes and other otherwise aqueous insoluble metal complexes, to give relatively neutral compositions without the need for acids, additional complexing agents, ammonia or amines or additional adjuvants. Also, for example, where the composition may be used in wood preservation, where one active ingredient does in fact solubilise the second otherwise insoluble active ingredient considerably minimising the added cost of adjuvants.

The immediate benefits from this technique are obvious. Cost of adjuvants can be eliminated in many situations and the need for acidic or alkaline conditions can also be eliminated.

This has a very specific advantage, for example, wherein biocidal composition may be required to preserve lignocellulosic composites. These products are typically manufactured using formaldehyde based adhesive systems where polymerisation of the resin is catalysed by acids. Acid solubilised biocides can cause premature polymerisation and therefore difficulties in production and plant cleanup.

The formulation of this patent results in a pH of approximately 8 depending on the ratio of raw materials used. This is very close to the pH (8.3) of a resin system and therefore poses no difficulties to normal production of composite materials regarding premature setting of the resin.

Further benefits can also accrue. When the formulation is applied to the substrate, interaction with the substrate will assist the desolubilisation of the metal complex allowing it to revert to its original insoluble form. This is a major advantage over the ammonia solublised metal complex formulations because the complex of this invention remains as a very aqueous insoluble metal complex. This has the advantage over current quaternary ammonium formulations in that the complex is more fixed to the substrate, and that the complexes have proven superior performance to the metal alone interacting with the substrate. It also offers the opportunity to significantly reduce leaching into the environment because loss from the substrate is reduced. Since the biological performance of the complex is greater than the metal alone, significantly lower use rates can be achieved, providing lower environmental impact and achieving significant cost benefits.

The fact that the metal complex reverts to its original complex form differentiates it from preceding technologies.

A yet further benefit accrues from the fact that metal complexes of this invention are reported to have far greater efficacy from being applied to the substrate at a higher pH than the aforementioned acid solubilised metal complexes.

According to the present invention there are provided compositions wherein complexes of metals are demonstrated to dissolve in aprotic solutions of ammonium, phosphonium and sulphonium compounds. Typically compounds such at metal 8- hydroxyquinolinolates, for example, copper 8-hydroxyquinolinolate (Oxine Copper) have very low solubility in water, under normal conditions around 0.22 parts per million. The literature also states the compound is insoluble in ethanol and common organic solvents. It has been found that by agitating the copper complex in aprotic and anhydrous quaternary compounds at elevated temperature that significant solubility can be gained, for example, as high as 20% (200000 ppm). This is a significant enhancement over previous techniques. Since at these very high levels the solution becomes an almost immobile fluid, the viscosity can be reduced by addition of aprotic solvents such as the glycol diethers, n-alkyl substituted pyrrolidones, lactones and numerous other aprotic solvents available and known to those versed in the art.

Although the concentrated solutions of metal complexes may find utility in a number of areas, for example, catalysis, it is convenient to note that when used as a biocide the solutions may be diluted directly with water to produce macro-emulsions or micro-emulsions depending on which quaternary compound is used, and that the physical properties of the emulsions can be manipulated by addition of further solvents and/or surfactants if so desired. These techniques are also known to those versed in the art of emulsion production.

A further advantage of this technology is that by selection of the quaternary compound and/or solvent, there is the ability to form transparent solutions or emulsions in organic solvent systems which might typically be used in wood preservation, for example, in aliphatic white spirts.

The metal selected for solubilisation may be any or a mixture of complexes of aluminium, bismuth, boron, cadmium, calcium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, thorium, titanium, tungsten, uranium, vanadium or zinc. Other cationic species such as beryllium, strontium and the rare earth metals also form complexes and are hereby included by implication. The preferred species for biological performance are copper, zinc, aluminium, nickel or mixtures thereof. Of these species copper, zinc and aluminium are more preferred, with copper being the most preferred.

Bismuth may be advantageously used to provide a level of colour to the substrate since, by way of an example of a metal organic complex, the bismuth 8- hydroxyquinolinolate is red in colour. Trace metal deficiences (eg. selenium) are also a possibility.

The metal(s) selected may be incoφorated directly into the formulation by dissolution of the metal 8-hydroxyquinolinolate, for example, (or other chelates) or by production in situ by reaction of 8-hydroxyquinoline (or other ligands) with a relatively weakly associated metal compound such as the carbonate, hydroxide, oxide or acetate although for economic reasons the hydroxide or oxide are preferred. ORGANIC COMPOUNDS

The organic compounds of this invention may be selected from those with preferably low solubihty in known common solvents as hereinbefore defined but may also include compounds which although otherwise soluble may be benefit from being used in the primary solubilising process of this invention.

Such low solubility compounds may include metal complexes such as Copper 8- hydroxyquinolinolate or other equivalent metal complexes; benzimidazoles such as Carbendazim, Albendazole, Mebendazole etc; triazoles including the benzotriazoles; indazoles; phthalonitriles such as Chloro thalonil; thiazoles such as Thiabendazole or Benzthiazuron. The selection of organic compound may include biocides selected from fungicides, insecticides, herbicides, anthelmintics, growth promotants, algacides, bactericides and others known to those versed in bio-control.

For example the present invention will allow pour-on formulations for the treatment of ecto-or endo-parasites where the or one of the biocidal compounds is such an organic moiety or a metal organic complex. Similarly with a range of transdermal medications.

MIXED CHELATES

Should a mixed chelate be required the ratio of metal 8-hydroxyquinolinolate (or other chelate) may be reduced, additional metal ions added and the remainder of the complex built by addition of a second (or third) complexing agent such as, for example, salicylic acid. In fact, the ratios are adjustable such that they may range from 100% primary chelate to 100% secondary chelate. Preferably the mol ratio of primary to secondary complexing agent or ligand is 1 : 1 as this is known to form a true compound with strong bio-activity, otherwise the composition becomes a mixture of complexes. By implication analogues of 8-hydroxyquinoline and salicylic acid are included, for example, 5-chloro-8-hydroxyquinoline, 5-chloro-salicylic acid or 2-hydroxy-naphthoic acid, but including other compounds and analogues such as nicotinic acid and picolinic acid and analogues, however for economic reasons unsubstituted 8-hydroxyquinoline and salicylic acid are preferred. The following structures illustrate some of the broad families of ligands or complexing agents which can be used, A preferred principal complexing ligand;

where R' and R" are sirnilar or different and selected from H, C l, F, I or Br.

Secondary ligands; 1)

R', R", R"' are similar or t and selected from H, Cl, F, I

2) Rl and R2 are COOH or Oh but wherein when one is COOH the other must be OH and where R', R", R'" are similar or different and selected from

H, Cl, F, I or Br or where R' and R" may combine to form an aromatic ring

3)

where R' is H, Me, Ph,Cl, F, I or Br.

4)

where R', R", R"' are H or OH but within only one need be OH.

'

where R' is OH.

THE "ONIUM" COMPOUND

The solubilising compound may be chosen from ammonium, phosphonium, arsonium. sulphonium or mixtures of these compounds. The compounds may have a variety of substituents including alkyl, aryl, alkaryl and variations of these. A large number and variety are produced commercially, the list too large to group in this document. Those versed in the art of quaternary chemistry will recognise the diversity of options. If producing a biocidal combination the choice might automatically revert to the dimethyl benzalkonium chlorides or the dialkyl dimethyl ammonium compounds since these have pronounced efficacy against fungi and bacteria in their own right and therefore in combination with biocidal metal complexes would produce effective products. There may however be a need in some circumstances where one might use a short chain quaternary such as tetrabutyl ammonium chloride, for other pm oses. Tne anion associated with the quaternary compound is not critical to the invention. Anions normally encountered include bromide, chloride, chlorate, fluoride, iodide, sulphate, nitrate and others. For reasons of cost one would preferably use chloride since this is normally commercially available, but special circumstances might dictate use of another.

The following illustrates some of the broad families of compounds which may be used; where X may be Cl, Br, F, I, S04, N03, C10₄ etc.

I X where A is N,P, or S

+ R', R", R"' is an alkyl or substituted alkyl

R'- - R'" group, but when A is S, R' is absent and R"

I R"' can not form an unsaturated ring

R'" R"" is an alkyl group, aralkyl group or oxygen, or R" and R"" form part of a saturated ring structure which may include one or more moieties such as N, O, S in the ring and may have substitution groups on the ring or R' is absent and R" and R"" form part of an unsaturated ring which may carry substitution groups

It has been stated that any solvents used for dilution or reduction in viscosity should necessarily be aprotic ie. have no accessible or labile hydrogen functionality as for example occurs with water, alcohol etc. This is because these materials cause reprecipitation of the metal complex. Many compounds exist which can fulfil the requirements including; glycol diethers eg. tetraethylene glycol dimethyl ether; n-alkyl pyrrolidones eg. n-octyl pyrrolidone; lactones eg. butyrolactone; ketones eg. acetophenone or cyclohexanone; lactams eg. caprolactam; morpholines eg. n-methyl morpholine or the n oxide; substituted ureas eg. tetramethyl urea; ring compounds containing oxygen and/or nitrogen groups eg. dioxane, dioxane, tetrahydrofuran, pyridine, alkyl carbonates, imidazolines. The group can be extended to include sulphoxides, amides, organic phosphates and where suited esters. The range is extensive and too large to fully document, the preferred properties are high solvency with very low protic functionality.

HLB

In some circumstances it may be preferred to alter the hydrotrope/lipotrope balance (HLB) of die final formulation where, for example, the solution might be diluted with, for example, water to form an emulsion. The HLB may be altered by addition of surfactant materials. This technique is well known to those versed in the art. Surfactants may be selected from a large range, recognising the potential incompatibility that can occur with quaternary compounds, including, betaines, phosphate esters, and nonionics such as amine or alcohol ethoxylates or propoxylates, glycol esters, or combinations thereof. Numerous other surfactants are also able to be substituted for those here listed.

CO-BIOCIDES OF A BIOCIDAL COMPLEX

Since the metal or organic biocidal complex solution may have utility as a biocide it may be convenient to include additional complementary or supplementary biocides. These can be chosen from insecticides eg. synthetic pyrethroids such as Perntithrin, Deltamethrin, Cypermethrin, etc; organochlorine insecticides such as Lindane; organophosphates such as Chlorpyriphos; or fungicides eg. triazoles such as Hexaconazole [(RS(-2-(2,4-dichlorophenyl)-l-(lH-l,2,4-triazol-l-yl)hexan-2ol], although Azaconazole, Tebuconazole, Cyproconazole, Flusilazole and Propiconazole, may be used depending on the biological problem to be controlled; phenols such as pentachlorophenol; isothiazolinones such as 4,5-dichloro-2-(n-octyl0-4-isothiazolinone; imidazoles; thiocyanates such as methylene bis thiocyanate; carbamates such as 3-iodo-2-propyl- butyl-carbamate; benzimidazoles such as Carbendazim; thalonitriles such as Chlorothalonil; n-nitroso-hydroxyamine metal salts such as bis-(n- cyclohexyldiazeniumdioxy)-copper; sulphones such as diiodo-para-tolyl-sulphone; and thiazoles such as 2-thiocyantomethylthio-benzothiazole. These may be conveniently added to the formulation of this invention or added subsequently during the dilution of the formulation with solvent. An advantage of adding these materials directly to the metal or organic compound complex solution (biocidal in its own might owing to (i) the metal or organic compound, and (ii) optionally the choice ofa biocidal "onium" compound) is that the additional components normally used to formulate the additive are not needed and therefore costs are reduced.

OTHER ADDITIVES

Optionally, the invention can contain other additives which might be employed with, for example, timber preservatives such as water repellents, colour additives, corrosion inhibitors, fire retardants and viscosity modifiers.

EXAMPLES

To demonstrate the art of this application, the following examples are provided. Numerous combinations are possible therefore the following offers a non-exhaustive guide to the possibilities.

Examples (where Oxine Copper represents copper 8-hydroxyquinolinolate)

Example I parts (w/w)

Oxine Copper 4

Benzalkonium chloride (50%) 30 n-methyl pyrrolidone 6

The oxine copper is heated with stirring in the 50% aqueous quaternary compound to 105 Celsius, continuing until all water has distilled off. The temperature is increased to approximately 150 Celsius until a red-brown solution with a green tinge is formed containing a concentration of Oxine Copper estimated at 16%.

Example 2

Oxine Copper 4

Benzalkonium chloride (50%) 20 butyrolactone 4

The procedure as in 1 was followed. A red-brown solution containing 22% Oxine Copper was formed. A sample of this solution was diluted with aliphatic white spirits to give a clear stable solution. Example 3

Oxine Copper 1

Octyldecyl quaternary (80%) 15

TEGDME 5

The Oxine Copper and quaternary were heated as in 1 to distill off ethanol from the quaternary. Upon cooling the solution because very viscous. Addition of tetraethylene glycol dimethyl ether (TGDME) gave a stable solution.

A sample of this solution was diluted by addition at 0.5% with agitation to water to produce a transparent micro-emulsion which upon standing formed a micro-suspension. Addition of higher concentration resulted in a pearlescent micro suspension.

Example 4

To 10 parts of example 4 were added 0.5 part of a proprietary phosphate ester surfactant. Dilution of this to 0.5% in water resulted in a colloidal micro suspension.

Example 5

1 Oxine Copper

Octyldecyl quaternary (80%) 10 n-octyl pyrrolidone 5

Processed as in 1. A red-brown solution estimated to contain 7.1% Oxine Copper is formed. Dilution with water forms a colloidal micro suspension.

Example 6

Oxine Copper 1

Octyldecyl quaternary (80%) 10

Processed as in 1. Forms a red-brown solution which on cooling becomes partially solid. Dilution in white spirit gives a clear solution which forms some precipitate over time.

Example 7

Addition of phosphate ester surfactant to example 6 gives a clear solution. Dilution in water gives a micro suspension. Example 8

To a portion of example 5 was added 0.5% of Hexaconazole technical. The triazole dissolved to give a clear solution.

Example 9

1

Oxine Copper

Benzalkonium Chloride 10 n-octyl pyrrolidone 5

Butyrolactone 5

Octyldecyl quaternary (80%) 10

The mixture was reacted witii stirring, giving a red-brown solution. Dilution of this with water gives a micro suspension. This example on dilution with xylene yielded a clear stable solution.

Addition of a phosphate ester surfactant to the xylene solution produced a solution which upon further dilution with water formed a stable macro-emulsion.

Example 10

To determine whether mixed chelates could also dissolve in the solvent system, the following mixture was prepared.

Oxine Copper 3.6

Cupric hydroxide 1.0

Salicylic acid 2.8

Benzalkonium Chloride (80%) 20 butyrolactone 6

The mixture was reacted giving as a red-brown solution, a mixed chelate of copper estimated at approximately 24% by weight.

Example 11

A quantity of cupric hydroxide was reacted alone with Benzalkonium Chloride. The blue suspension of hydroxide was rapidly dehydrated to black cupric oxide, insoluble in the anhydrous quaternary compound. Addition of a stoichiometric amount of salicylic acid gave rapid dissolution to produce a solution of the metal complex. Example 12

To a sample from Example 7 was added 5% Permethrin technical. The Permethrin dissolved to give a clear solution. Dilution to 2% in water resulted in a transparent emulsion.

Example 13 Oxine Copper 4

Octyi decyl quat (80%) 30

BLO 6

This mixture was heated gradually with stirring and to distill off the ethanol contained in the quat sample. Subsequently the temperature was raised to 150 Celsius and stirring continued until the Oxine Copper had completely dissolved. A sample was added to aliphatic white spirits to provide a clear solution. A further sample was accurately diluted with white spirit to produce a clear solution of 6.8% w/v as formulated product for treatment of wooden stakes, for biological testing to determine the efficacy of the solution for control of wood decaying fungi. The solution was clear but very dark green in colour.

Example 14

Benzalkonium Chloride 80% solution in n-methylpyrrolidone 80 parts

Carbendazim 4.55 parts

Cyproconazole 4.55 parts

The above ingredients were heated to 100°C with stirring to give a clear amber liquid which contained 5.11% Carbendazim, 5.11% Cyproconazole and 71.8% Benzalkonium Chloride and a total active ingredient concentration of 82.0%.

Claims

CLAIMS:

1. A solution (solid or liquid) of at least one biocide which is a "metal organic complex or an organic moiety" which, at least in the absence of extreme conditions of pH (high or low), is of low solubihty or insoluble in "common solvents", said solution having being prepared by dissolution of the biocide(s) with heating in

(i) an anhydrous "onium" compound or anhydrous "onium" compounds, or (ii) a polar aprotic solvent solution of an anhydrous "onium" compound or anhydrous "onium" compounds.

2. A solution of claim 1 wherein said "metal organic complex or an organic moiety" was prepared prior to the presence of the anhydrous "onium" compound or compounds.

3. A solution of claim 1 wherein said "metal organic complex or an organic moiety" was prepared subsequent to the presence of the anhydrous "onium" compound or compounds.

4. A solution of claim 1 wherein said "metal orgamc complex or an organic moiety" was prepared at least in part during the presence ofthe anhydrous "onium" compound or compounds

5. A solution of any one of the preceeding claims wherein no aprotic solvent (as in (ii)) is present during such dissolution.

6. A solution as in any one ofthe preceding claims wherein at least one biocide is an organic moiety of low solubility in common solvents in the absence of extremes of pH.

7. A solution as in claim 6 wherein at least one said biocide is a benzimidazole.

8. A solution as in claim 7 wherein at least one said biocide is Carbendazim.

9. A solution as claimed in any one ofthe preceding claims wherein at least one said biocide is a metal chelate.

10. A solution as claimed in claim 10 wherein said metal chelate is a chelated biocidal metal and the chelating agent is selected from 8-hydroxyquinoline or analogues thereof, hydroxy aromatic acids or analogues thereof, nicotinic or picolinic acid or analogues thereof, or mixtures thereof.

11. A solution as claimed in claim 9 or 10 wherein said metal chelate is a chelate with 8-hydroxyquinolinolate ligands or is a mixed chelate of which at least one ligand is an 8-hydroxyquinolinolate.

12. A solution as claimed in any one of the preceding claims wherein said onium compound is selected from the group consisting of quaternary ammonium, quaternary sulphonium and quaternary phosphonium compounds and amine, phosphine oxide and sulphoxide equivalents of the parent compound.

13. A solution as claimed in any one of the preceding claims wherein said onium compound is anhydrous and free from protic solvents.

14. A solution as claimed in any one of the preceding claims wherein the at least one said biocide includes an atom of at least one of the group consisting of atoms of aluminium, bismuth, boron, cadmium, calcium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, thorium, titanium, tungsten, uranium, vanadium and zinc.

15. A solution as claimed in claim 14 wherein said biocide includes an atom selected from atoms of copper, zinc and aluminium.

16. A solution as claimed in claim 15 wherein said atom is that of copper.

17. A solution as claimed in any one of the preceding claims wherein the resulting solution has been diluted by a polar aprotic solvent to reduce viscosity.

18. A solution as claimed in any one of the preceding claims wherein said onium compound(s) is or are biocidal.

19. A solution of any one ofthe preceding claims wherein a coloured metal chelate is included.

20. A solution of claim 19 wherein said coloured metal chelate is bismuth 8- hydroxyquinolinolate .

21. A solution of any one ofthe preceding claims wherein said polar aprotic solvents) is selected from the group consisting of glycol diethers, n-alkyl pyrrolidones, lactones, ketones, lactams, moφholines, substituted ureas, ring compounds containing oxygen and/or nitrogen groups, alkyl carbonates, cyclic carbonates, imidazolines, suplhoxides, amides, organic phosphates and, where suited, esters.

22. A solution as claimed in any one of the preceding claims including more than one biocide.

23. A solution as claimed in claim 1 wherein solution includes more than one biocide, each biocide having been dissolved with heating in the or an anhydrous "onium" compound or compounds (whether separately dissolved and subsequently blended or dissolved together).

24. A solution of claim 22 or 23 wherein one or more biocide(s) is a synthetic pyrethroid, an organochlorine, an organophosphate, a triazole, a phenol, an isothiazolinone, an imidazole, a thiocyanate, a carbamate, a benzimidazole, a thalonitrile, a n-nitroso-hydroxyamine metal sale, a sulphone and/or a thiazole.

25. A solution as claimed in claim 24 wherein one biocide is a metal chelate and the other biocide or biocides are added, if desired or necessary, after the dissolution with heating of the metal chelate in the anhydrous onium compound.

26. A solution as claimed in any one of the preceding claims that is liquid at ambient temperatures.

27. A solution as claimed in any one of the preceding claims wherein the hydrotrope/lipotrope balance [HLB] has been altered subsequent to the biocide(s) dissolution.

28. A composition which is a solution of any one of the preceding claims which also includes at least one surfactant.

29. A composition which is a solution of any one of claims 1 to 27 or a composition of claim 26 wherein there is subsequently also an aqueous phase.

30. A composition of claim 29 in the form of a micro suspension or micro emulsion.

31. A composition of any one of the preceding claims substantially as hereinbefore described with or without reference to any Example thereof.

32. A method of preparing a biocidal solution (solid or liquid) which comprises the steps of (i) for a single biocidal compound, or (ii) for a mixture of biocidal compounds, or (iii) for separate biocidal compounds, dissolving each biocidal compound in an anhydrous onium compound (or compounds) [optionally including a highly polar aprotic solvent] with heating,

33. A method of solubilizing a biocide ("low solubility biocide") which is a metal organic complex or an organic moiety which, at least in the absence of extreme conditions of pH (high or low), is of low solubility or insoluble in "common solvents", said method comprising i) dissolving with heating the low solubihty biocide (with or without any other biocidal compound) in an anhydrous "onium" compound or compounds, and ii) optionally, reducing the viscosity by dilution with an aprotic solvent, and iii) optionally, before or after optional step (ii) [if any step (ii)] blending the solution of step (i) or derived from step (i) with another biocide or a solution of another biocide.

34. A method of claim 32 or 33 wherein said heating is to a temperature or temperatures of from 50°C to 170°C.

35. A method as claimed in any one of claims 32 to 34 wherein said "metal organic complex or an organic moiety" was prepared prior to the presence of the anhydrous "onium" compound or compounds.

36. A method as claimed in any one of claims 32 to 34 wherein said "metal organic complex or an organic moiety" was prepared subsequent to the presence of the anhydrous "onium" compound or compounds.

37. A method as claimed in any one of claims 32 to 34 wherein said "metal orgamc complex or an organic moiety" was prepared at least in part during the presence of the anhydrous "onium" compound or compounds

38. A method as claimed in any one of claims 32 to 37 wherein no aprotic solvent (as in (ii)) is present during such dissolution.

39. A method as claimed in any one of claims 32 to 38 wherein at least one biocide is an organic moiety of low solubihty in common solvents in the absence of extremes of pH.

40. A method as claimed in any one of claims 32 to 39 wherein at least one said biocide is a benzimidazole.

41. A method as claimed in any one of claims 32 to 40 wherein at least one said biocide is Carbendazim.

42. A method as claimed in any one of claims 32 to 41 wherein at least one said biocide is a metal chelate.

43. A method as claimed in claim 42 wherein said metal chelate is a chelated biocidal metal and the chelating agent is selected from 8-hydroxyquinoline or analogues thereof, hydroxy aromatic acids or analogues thereof, nicotinic or picolinic acid or analogues thereof, or mixtures thereof.

44. A method as claimed in claim 42 wherein said metal chelate is a chelate with 8- hydroxyquinolinolate ligands or is a mixed chelate of which at least one ligand is an 8- hy droxy quinolinolate .

45. A method as claimed in any one of claims 32 to 44 wherein said onium compound is selected from the group consisting of quaternary ammonium, quaternary sulphonium and quaternary phosphonium compounds and amine, phosphine oxide and sulphoxide equivalents of the parent compound.

46. A method as claimed in any one of claims 32 to 45 wherein said onium compound is anhydrous and free from protic solvents.

47. A method as claimed in any one of claims 32 to 46 wherein the at least one said biocide includes an atom of at least one of the group consisting of atoms of aluminium, bismuth, boron, cadmium, calcium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, thorium, titanium, tungsten, uranium, vanadium and zinc.

48. A method as claimed in any one of claims 32 to 47 wherein said biocide includes an atom selected from atoms of copper, zinc and aluminium.

49. A method as claimed in claim 48 wherein said atom is that of copper.

50. A method as claimed in any one of claims 32 to 49 wherein the resulting solution has been diluted by a polar aprotic solvent to reduce viscosity.

51. A method as claimed in any one of claims 32 to 50 wherein said onium compound(s) is or are biocidal.

52. A method as claimed in any one of claims 32 to 51 wherein a coloured metal chelate is included.

53. A method as claimed in claim 52 wherein said coloured metal chelate is bismuth 8-hydroxyquinolinolate.

54. A method as claimed in any one of claims 32 to 53 wherein said polar aprotic solvent(s) is selected from the group consisting of glycol diethers, n-alkyl pyrrolidones, lactones, ketones, lactams, moφholines, substituted ureas, ring compounds containing oxygen and/or nitrogen groups, alkyl carbonates, cyclic carbonates, imidazolines, suplhoxides, amides, organic phosphates and, where suited, esters.

55. A method as claimed in any one of claims 32 to 54 including more than one biocide.

56. A method as claimed in any one of claims 32 to 55 wherein the solution includes more than one biocide, each biocide having been dissolved with heating in the or an anhydrous "onium" compound or compounds (whether separately dissolved and subsequently blended or dissolved together).

57. A method as claimed in any one of claims 32 to 56 wherein one or more biocide(s) is a synthetic pyrethroid, an organochlorine, an organophosphate, a triazole, a phenol, an isothiazolinone, an imidazole, a thiocyanate, a carbamate, a benzimidazole, a thalonitrile, a n-nitroso-hydroxyamine metal sale, a sulphone and or a thiazole.

58. A method as claimed in any one of claims 32 to 57 wherein one biocide is a metal chelate and the other biocide or biocides are added, if desired or necessary, after the dissolution with heating ofthe metal chelate in the anhydrous onium compound.

59. A method as claimed in any one of claims 32 to 58 wherein the resulting solution is liquid at ambient temperatures.

60. A method as claimed in any one of claims 32 to 59 wherein the hydrotrope lipotrope balance [HLB] is altered subsequent to the biocide(s) dissolution.

61. A method as claimed in any one of claims 32 to 60 wherein the resulting solution is altered to include at least one surfactant.

62. A method as claimed in any one of claims 32 to 61 wherein the solution is then modified so that there is also an aqueous phase.

63. A method as claimed claim 62 wherein a micro suspension or micro emulsion results.

64. A method as claimed in any one of claims 32 to 63 when performed substantially as hereinbefore described with or without reference to any Example thereof.

65. A composition of at least two biocides wherein at least one of the biocides is a metal chelate, the composition having the metal chelate dissolved without the need to resort to use of phenols, strong acids or metal soaps, in an anhydrous aprotic compound chosen from quaternary compounds of nitrogen and phosphorus, tertiary compounds, sulphur and amine, phosphine oxide or sulphoxide equivalent.

66. A composition of claim 65 wherein the metal chelate is the 8-hydroxyquinoline chelate of copper and the dissolution has required heating.

67. A method of fixing a biocidal metal species or organic species in an environment subject to aqueous leeching, said method comprising applying into said environment the biocidal species whilst solubilised in an onium compound (with or without dilution with an aprotic diluent).

68. A method of claim 67 wherein the biocidal species is applied as a solution or composition of any one of claims 1 to 31, 65 and 66.

69. A biocidally treated matrix or animal, said matrix or animal being an environment treated by a solution or composition of any one of claim 1 to 31, 65 and 66 or by a method of claim 67 or 68.

70. The animal pour on application of a solution or composition of any one of claims l to 31.

71. The biocidal product of the method of any one of claims 32 to 64.