AU2016204205A1 - Method of preparing metal carboxylates - Google Patents

Abstract

The present invention relates to a method for preparing metal carboxylates. The method comprises providing a composition comprising a metal, an amine, and a carboxylate, optionally in a liquid medium; and decomposing the composition to form a metal carboxylate comprising the metal and at least one carboxylate. The present invention also relates to metal carboxylates prepared by that method. The metal carboxylates may be useful for example as drying agents for alkyd paints, catalysts for polyester resins, lubricants and as biocidal agents in the preservation of wood.

Description

1 2016204205 21 Jun2016

METHOD OF PREPARING METAL CARBOXYLATES

This application claims priority from New Zealand patent application 709548, filed 29 June 2015, the entire content of which is incorporated herein by reference. 5

TECHNICAL FIELD

The present invention generally relates to a method for preparing metal carboxylates. In particular, the present invention relates to a method of preparing carboxylates of metals, 0 such as naphthenates, stearates, and ethylhexanoates, and metal carboxylates prepared by that method.

BACKGROUND OF THE INVENTION 5 Metal carboxylates (for example, metal soaps) have been in use for at least 70 years, possibly longer.

These compounds are relatively simple, but can be complicated to make because some of the reactants are water soluble but the compounds themselves may not be. The processes !0 used will typically, at least at some point, comprise two phases - an aqueous phase and a non-aqueous phase.

Feed stocks used in the preparation of metal carboxylates typically need to be manufactured separately prior to use. Manufacturing such feed stocks requires additional plant and 25 equipment and adds additional steps to the overall process, increasing costs.

The processes also typically involve the production of waste steams or by-products that often require further processing, which requires additional plant and equipment and adds to costs. 30

Typically metal carboxylates are manufactured by one of two methods: (i) direct reaction between a metal compound insoluble in water with an organic acid, or (ii) reaction between an alkali salt of the organic acid with a water soluble metal salt. 35 For example, US 2472424, which we incorporate herein by reference, reports the manufacture of copper naphthenate by direct reaction of copper oxide, copper hydroxide, copper carbonate and the like with naphthenic acid. 2 2016204205 21 Jun2016 GB 498011, which we also incorporate herein by reference, reports the manufacture of a range of siccatives (metallic drying agents) by the reaction of an organic acid with an alkali and then reaction of the resultant alkali salt with certain water soluble metal salts, for 5 example cobalt sulfate. US 2423619 reports the preparation of ammoniacal copper soaps, and their application as fungicides. Such fungicides are at least partially soluble in water and on application to cellulosic substrates such as wood are susceptible to leaching. 0

There is an ongoing a need for methods of preparing metal carboxylates that are simple, efficient, and/or cost effective; and/or that avoid one or more of the disadvantages of the prior art. It is an object of the present invention to go some way towards meeting this need; and/or at least to provide the public with a useful choice. 5

Other objects of the invention may become apparent from the following description which is given by way of example only.

Any discussion of documents, acts, materials, devices, articles or the like which has been !0 included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date.

25 SUMMARY OF THE INVENTION

In one aspect, the present invention broadly consists in a method for preparing a metal carboxylate, the method comprising: providing a composition comprising a metal, an amine, and a carboxylate, optionally 30 in a liquid medium; and decomposing the composition to form a metal carboxylate comprising the metal and at least one carboxylate.

In another aspect, the present invention broadly consists in a method for preparing a metal 35 carboxylate, the method comprising: providing a metal amine carboxylate comprising a metal, at least one amine, and at least one carboxylate, optionally in a liquid medium; and 3 2016204205 21 Jun2016 decomposing the metal amine carboxylate to remove the at least one amine and form a metal carboxylate comprising the metal and at least one carboxylate.

In another aspect, the present invention broadly consists in a metal carboxylate comprising a 5 metal and at least one carboxylate prepared by a method of the present invention.

The following embodiments and preferences may relate alone or in any combination of any two or more to any of the aspects above. 0 In various embodiments, providing the composition comprises providing a metal source, an amine source, and a carboxylate source; and reacting the metal source, the amine source, and the carboxylate source in any order, optionally in a liquid medium, to form the composition. 5 In various embodiments, decomposing the composition comprises heating the composition, optionally under reduced pressure.

In various embodiments, decomposing the composition comprises separating the amine from the composition. !0

In various embodiments, decomposing the composition comprises evaporating the amine from the composition.

In various embodiments, providing the composition comprises providing a metal amine 25 carboxylate comprising a metal, at least one amine, and at least one carboxylate.

In various embodiments, decomposing the composition comprises decomposing the metal amine carboxylate to remove the at least one amine and form the metal carboxylate. 30 In various embodiments, providing the composition comprises providing a reaction product of a metal source and an amine source; and reacting a carboxylate source with the reaction product to form the composition.

In various embodiments, the reaction product comprises a metal amine comprising a metal 35 and at least one amine. 4 2016204205 21 Jun2016

In various embodiments, providing the metal amine carboxylate comprises providing a metal amine comprising a metal and at least one amine; and reacting the metal amine with a carboxylate source, optionally in a liquid medium, to form the metal amine carboxylate. 5 In various embodiments, the metal amine carboxylate is a saturated or unsaturated metal amine carboxylate.

In various embodiments, providing the metal amine comprises reacting a metal source and an amine source, optionally in a liquid medium, to form the metal amine. 0

In various embodiments, decomposing the metal amine carboxylate to form the metal carboxylate comprises heating the metal amine carboxylate, optionally under reduced pressure, to remove the at least one amine. 5 In various embodiments, the method comprises separating the amine removed from the metal amine carboxylate from the metal carboxylate.

In various embodiments the metal is a biocidal metal. !0 In various embodiments, the metal is selected from the metals of groups 3 to 15 of the periodic table.

In various embodiments, the metal is selected from the group consisting of copper, zinc, iron, cobalt, manganese, antimony, bismuth, titanium, zirconium, nickel. 25

In various embodiments, the metal is selected from the group consisting of copper, zinc, iron, cobalt, manganese, and nickel.

In various embodiments, the metal is copper or zinc. In various embodiments, the metal is 30 copper.

In various embodiments, the amine is selected from the group consisting of ammonia and organic amines, or a combination of any two or more thereof. 35 In various embodiments, the amine is volatile, for example ammonia or a volatile organic amine. 5 2016204205 21 Jun2016

In various embodiments, the amine is a volatile organic amine. In various embodiments, the volatile organic amine has a boiling point of less than about 100 O, for example less than about 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, or 40 *C. 5 In various embodiments, the organic amine comprises from 1 to 10, 1 to 8, 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

In some embodiments, the organic amine is a primary amine, a secondary amine or a tertiary amine. In various embodiments, the organic amine is trimethylamine. 0

In various embodiments, the amine is ammonia.

In various embodiments, the carboxylate is a carboxylate of a non-volatile carboxylic acid. In various embodiments, the carboxylate is a carboxylate of a carboxylic acid having a boiling 5 point of greater than 75, 100, 125, 150, 175, 200, or 225 Ό.

In various embodiments, the carboxylate is a carboxylate of a substantially water insoluble carboxylic acid. In various embodiments, the carboxylate is a carboxylate of a carboxylic acid having a water-octanol partition coefficient (log Kow) of at least about 1, 1.5,1.7, 1.8, !0 1.9, 2.0, 2.2, or 2.4.

In various embodiments, the carboxylate comprises at least two carbon atoms, for example, at least about 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. In certain embodiments, the carboxylate comprises from 4 to 100, 4 to 80, 4 to 50, 4 to 30, 4 to 20, 6 to 80, 6 to 50, 6 to 30, 6 to 20, 8 25 to 50, 8 to 30, 8 to 20 carbon atoms.

In various embodiments, the carboxylate has a molecular weight of at least about 75 g/mol, for example, at least about 100, 125, or 150 g/mol. In various embodiments, the carboxylate has a molecular weight from about 75 to 1,000 g/mol, for example, about 75 to 750, 75 to 30 500, 100 to 1,000, 100 to 750, or 100 to 500 g/mol.

In various embodiments, the carboxylate is a group of formula RC(0)0, wherein R is an organic group. 35 In various embodiments, the organic group comprises one or more aliphatic (for example ethylenic), alicyclic, heteroaliphatic, heteroalicyclic, aryl, or heteroaryl groups. 6 2016204205 21 Jun2016

In various embodiments, the organic group comprises a linear or branched hydrocarbon chain optionally comprising one or more hydrocarbon rings in the chain, or a cyclic (including polycyclic) hydrocarbon group. In various embodiments, the hydrocarbon chain, hydrocarbon ring(s), and cyclic hydrocarbon group are optionally substituted with one or 5 more aliphatic, alicyclic, heteroaliphatic, heteroalicyclic, aryl, or heteroaryl groups.

In various embodiments, the organic group may comprise from 5 to 100, 5 to 80, 5 to 50, or 5 to 30 carbon atoms. 0 In various embodiments, the carboxylate is a C8-20, preferably C10-16, alicyclic carboxylate, for example a naphthenate; a fatty acid, for example a C4-28, preferably C6 to 22 or C6 to 20, fatty acid such as a stearate, linoleate, or ethylhexanoate; a C15-C30, preferably C20, polycyclic alicyclic carboxylate, for example an abietate. 5 In various embodiments, the carboxylate is selected from the group consisting of naphthenates, stearates, linoleates, ethylhexanoates, and abietates.

In various embodiments, the carboxylate is a stearate, naphthenate, or 2-ethylhexanoate. !0 In various embodiments, the liquid medium comprises water, a polar organic solvent, a nonpolar organic solvent, a water miscible organic solvent, a water immiscible organic solvent, or a combination of any two or more thereof.

In various embodiments, the liquid medium comprises water, a polar organic solvent, a water 25 miscible organic solvent, or a combination of any two or more thereof.

In various embodiments, the liquid medium comprises water and optionally one or more water miscible organic solvents. 30 Preferably, the liquid medium is water, an alcohol, preferably a C1-4 alcohol, preferably methanol or ethanol, or a mixture of any two or more thereof.

In various embodiments, the liquid medium comprises water, methanol, ethanol, propanol, butanol, or a combination of any two or more thereof. 35

Preferably, the liquid medium comprises water. In various embodiments, the liquid medium comprises an aqueous phase. 7 2016204205 21 Jun2016

In various embodiments, the liquid medium comprises two or more liquid phases. In various embodiments, the liquid medium comprises an aqueous phase comprising water and an organic phase one or more water immiscible organic solvents. 5

In various embodiments, the method comprises separating the liquid medium from the composition comprising the metal, amine, and carboxylate or from the metal carboxylate.

In various embodiments, the amine and/or liquid medium is separated by evaporation at a 0 temperature and pressure sufficient to evaporate the amine and/or liquid medium.

In various embodiments, the amine and/or liquid medium is separated by evaporation during and/or after formation of the metal carboxylate. 5 In various embodiments, the method comprises collecting and optionally recycling the separated amine and/or liquid medium.

In various embodiments, the amine and/or liquid medium is separated by evaporation and collected by condensation, optionally for reuse. !0

In various embodiments, the amine and/or liquid medium are separated and collected, optionally for reuse, by vacuum condensation.

In various embodiments, decomposing the composition comprising the metal, amine, and 25 carboxylate provides a multiphasic composition comprising a first liquid phase comprising the metal carboxylate, and a second liquid phase comprising the liquid medium or a liquid phase thereof.

In various embodiments, the metal source is substantially water insoluble. 30

In various embodiments, the metal source comprises a substantially water insoluble metal salt, a volatile organic acid metal salt, elemental metal, or a combination of any two or more thereof. In various embodiments, the metal source is a substantially water insoluble metal salt or elemental metal. 35 8 2016204205 21 Jun2016

In various embodiments, the substantially water insoluble metal salt has a solubility in water of less than about 1x10~4 g/L, for example less than about 0.1 x 10'4, 0.001 x 10 4, or 0.0001 x 104 g/L. 5 In various embodiments, the metal source comprises a metal oxide, hydroxide, or carbonate, a formic acid or acetic acid metal salt, elemental metal, or a combination of any two or more thereof.

In some embodiments, the metal source is a metal oxide, hydroxide, or carbonate. 0

In other embodiments, the metal source is metal salt of a volatile organic acid, such as formic or acetic acid.

In other embodiments, the metal source is elemental metal. Preferably, the metal source is 5 elemental copper (i.e. metallic copper).

In various embodiments, providing the metal amine comprises reacting a metal source (for example elemental metal) and an oxidant optionally in the presence of the amine source and/or carboxylate source. !0

In various embodiments, the method comprises reacting the metal source (for example elemental metal) and an oxidant, optionally in the presence of the amine source and/or carboxylate source, to oxidise the metal. 25 In various embodiments, reacting the metal source (for example elemental metal), amine source, and carboxylate source comprises reacting the metal source and an oxidant, optionally in the presence of the amine source and/or carboxylate, to oxidise the metal.

In various embodiments, the method comprises reacting a metal source (for example 30 elemental metal), an oxidant, an amine source, and carboxylate source in any order, optionally in a liquid medium, to oxidise the metal and form the composition or metal amine carboxylate.

In various embodiments, the method comprises: 35 reacting a metal source (for example elemental metal), an oxidant, and amine source, optionally in a liquid medium, to oxidise the metal and form a reaction product; and reacting the reaction product and the carboxylate source to form the composition. 9 2016204205 21 Jun2016

In various embodiments, the oxidant is air or oxygen (e.g. the reacting is carried out under an atmosphere of air or oxygen). 5 In various embodiments, the method comprises: reacting a metal source comprising elemental metal (for example metallic copper) and an amine source (for example ammonia) under an atmosphere of air or oxygen, optionally in a liquid medium, to oxidise the metal and form a reaction product; and reacting the reaction product and the carboxylate source to form the composition. 0

In various embodiments, the amine source is an amine or a salt thereof.

In various embodiments, the carboxylate source is a carboxylic acid or a salt thereof. 5 The term “comprising” as used in this specification, including the claims, means “consisting at least in part of”. When interpreting each statement in this specification, including the claims, that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner. !0

It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1,2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges 25 expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. 30 As used herein the term “and/or” means “and” or “or”, or both.

As used herein “(s)” following a noun means the plural and/or singular forms of the noun.

The term “amine” as used herein unless indicated otherwise is intended to include both 35 ammonia and organic amines. In the metal amines and metal amine carboxylates described herein, the term “amine” may refer to an ammonia or organic amine ligand coordinated to the 10 2016204205 21 Jun2016 metal. Ammonia ligands in the metal amines and metal amine carboxylates may also be referred to herein as ammines.

The term “amino group” as used herein unless indicated otherwise is intended to include -5 NR2 groups, wherein each R is independently hydrogen or an organic group, such as an aliphatic group. In ammonia, the nitrogen atom of the amino group (-NH2) is bound to another hydrogen atom. In an organic amine, the nitrogen atom of the amino group is bound to a carbon atom of an organic group. 0 The term “carboxylate group” as used herein unless indicated otherwise is intended to include -C(0)0' groups. 5 !0

The term "aliphatic" as used herein unless indicated otherwise is intended to include saturated and unsaturated, straight chain or branched hydrocarbon groups. Those skilled in the art will appreciate that aliphatic groups include, for example, alkyl, alkenyl, and alkynyl (e.g. ethylenic) groups, and the like. In some embodiments, aliphatic groups have from 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,22, 23, 24, 25, 26, 27, 28, 29, or 30 carbon atoms, and useful ranges may be selected from any two of these values, for example 1-30, 4-30, 5-30, 6-30, 10-30, 15-30, 20-30, 4-28, 6-28, 8-28, 10-28, 5-25, 10-25, 15-25, 6-22, 8-22, 10-22, 6-20, 8-20, 10-20, 6-18, 8-16, or 10-16 carbon atoms.

The term “alicyclic” as used herein is intended to include non-aromatic cyclic (including polycyclic) aliphatic groups. Those skilled in the art will appreciate that alicyclic groups include, for example, cycloalkyl and cycloalkenyl groups, and the like. Polycyclic alicyclic 25 groups include bridged, spiro, and fused ring systems. Alicyclic groups comprise at least 3 carbon atoms. In various embodiments, aliphatic groups have from 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,22, 23, 24, 25, 26, 27, 28, 29, or 30 carbon atoms, and useful ranges may be selected from any two of these values, for example 3-30, 4-30, 5-30, 6-30, 10-30, 15-30, 20-30, 4-28, 6-28, 8-28, 10-28, 5-25, 10-25, 15-25, 6-22, 8-22, 10-22, 6-30 20, 8-20, 10-20, 6-18, 8-16, or 10-16 carbon atoms.

The term "heteroaliphatic" as used herein unless indicated otherwise is intended to include aliphatic groups in which one or more carbon atoms in the main chain have been substituted with a heteroatom, preferably Ο, N, or S. 35 11 2016204205 21 Jun2016

The term "heteroalicyclic" as used herein unless indicated otherwise is intended to include alicyclic groups in which one or more ring carbon atoms have been substituted with a heteroatom, preferably Ο, N, or S. 5 The term “alkyl” as used herein unless indicated otherwise is intended to include straight chain and branched chain saturated hydrocarbon groups. In some embodiments, alkyl groups have from 1 to 12, 1 to 8, or 1 to 6 carbon atoms.

The term "aryl" as used herein unless indicated otherwise is intended to include cyclic 0 (including polycyclic) aromatic hydrocarbon groups. Examples include but are not limited to phenyl, naphthyl, and the like. In some embodiments, aryl groups have from 6-14, from 6 to 12, or from 6-10 ring carbon atoms. Polycyclic aryl groups include fused aromatic-aliphatic ring systems. 5 The term "heteroaryl" as used herein unless indicated otherwise is intended to include cyclic aromatic groups comprising one or more ring heteroatoms, preferably selected from Ο, N , and S. In some embodiments, heteroaryl groups include mono-, bi- and tricyclic ring systems having from 5 to 16, from 5 to 14, from 5 to 12, from 5 to 10, from 5 to 8, or from 5 to 6 ring atoms. !0

Unless specified otherwise, any of the groups defined herein may be optionally substituted. The term “substituted” as used herein with reference to any of the groups defined herein means a group wherein at least one hydrogen atom is replaced by a substituent other than hydrogen, provided that the normal valency of each atom to which the substituent(s) are 25 attached is not exceeded, and that the substitution results in a stable compound. In various embodiments, the substituents are selected from the group consisting of aliphatic; alicyclic; heteroaliphatic; heteroalicyclic; aryl; heteroaryl; alkylaryl; alkylheteroaryl; alkoxy; aryloxy; heteroalkoxy; heteroaryloxy; alkylthio; arylthio; heteroalkylthio; heteroarylthio; halo; hydroxyl; nitro; cyano; haloalkyl; -alkylORx;-alkylS02alkyl; -C(0)Rx; -C02(Rx); -CON(Rx)2; -0C(0)Rx 30 -0C02Rx; -OCON(Rx)2; -S(0)2Rx wherein each occurrence of Rx independently includes, but is not limited to, H, aliphatic, alicyclic, heteroaliphatic, heteroalicyclic, aryl, heteroaryl, alkylaryl, or alkylheteroaryl, wherein any of the aliphatic, alicyclic, heteroaliphatic, heteroalicyclic, aryl, heteroaryl, alkylaryl, or alkylheteroaryl substituents may be substituted or unsubstituted. 35 12 2016204205 21 Jun2016

The term “stable” as used herein refers to compounds which possess stability sufficient to allow manufacture and which maintain their integrity for a period of time sufficient to be useful for the purposes described herein. 5 Unless indicated otherwise, all temperatures given herein are at standard atmospheric pressure.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves 0 without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.Although the present invention is broadly as defined above, those persons skilled in the art will appreciate that the invention is not limited thereto and that the invention also includes embodiments of which the following description gives examples. 5

DETAILED DESCRIPTION OF THE INVENTION

The inventor has advantageously found that metal carboxylates may be readily accessed by decomposing a composition comprising a metal, an amine, and a carboxylate. I0

Accordingly, in one aspect the present invention provides a method for preparing a metal carboxylate, the method comprising: providing a composition comprising a metal, an amine, and a carboxylate, optionally in a liquid medium; and 25 decomposing the composition to form a metal carboxylate comprising the metal and at least one carboxylate.

The composition comprising the metal, the amine, the carboxylate may comprise a metal amine carboxylate comprising a metal, at least one amine, and at least one carboxylate. 30 Metal carboxylate may be formed by decomposing the metal amine carboxylate to remove the at least one amine from the metal amine carboxylate.

Thus, in another aspect, present invention provides a method comprising the steps of: providing a metal amine carboxylate comprising a metal, at least one amine, and at 35 least one carboxylate, optionally in a liquid medium; and decomposing the metal amine carboxylate to remove the at least one amine and form a metal carboxylate comprising the metal and at least one carboxylate. 13 2016204205 21 Jun2016

The present invention also provides a metal carboxylate prepared by the method.

The composition may be provided by reacting a metal source, an amine source, and a 5 carboxylate source simultaneously or sequentially in any order. In various embodiments, the composition may be provided by reacting a metal source and an amine source to form a reaction product, and reacting the reaction product with a carboxylate source. The reaction product may comprise a metal amine. 0 The metal amine carboxylate may be provided by reacting the metal amine with a carboxylate source. The metal amine may be formed in situ in the presence of a carboxylate source or in the absence of a carboxylate source. In various embodiments, the metal amine is formed in the absence of a carboxylate source, and a carboxylate source may be introduced after the metal amine has been formed to form the metal amine carboxylate. 5

Reaction of the metal source, the amine source, and the carboxylate source may be carried out in a suitable liquid medium. Alternatively, where one or more of the starting materials are liquid, the reaction may be carried out without a liquid medium (i.e. neat). In such embodiments, the starting material itself (for example 2-ethylhexanoic acid, which is liquid at !0 ambient temperature) acts as the medium for the reaction.

The liquid medium typically comprises one or more solvents. Suitable solvents include, but are not limited to, water, polar organic solvents, non-polar organic solvents, water miscible organic solvents, water immiscible organic solvents, and combinations of any two or more 25 thereof. The solvent may be protic and aprotic. Examples of suitable polar solvents include alcohols, for example simple alcohols such as methanol, ethanol, and propanol, and polyhydric alcohols such as ethylene glycol and glycerol. Other solvents include, for example dimethylformamide, dimethylacetamide, acetonitrile, dimethylsulfoxide, and N-methylpyrrolidone and hydrocarbons, which may be useful in embodiments where the liquid 30 medium comprises an organic phase, such as diesel and the like.

In various embodiments, the liquid medium comprises water, a polar organic solvent, a water miscible organic solvent, or a combination of any two or more thereof. In various embodiments, the liquid medium comprises water and optionally one or more water miscible 35 organic solvents. In various embodiments, the liquid medium comprises or is water, a Ci-4alcohol, preferably methanol or ethanol, or a mixture of any two or more thereof.

Preferably, the liquid medium comprises water. 14 2016204205 21 Jun2016 A liquid medium described herein may comprise two or more liquid phases. In various embodiments, the liquid medium comprises an aqueous phase comprising water and organic phase comprising one or more water immiscible solvents, for example one or more 5 hydrocarbons such as diesel.

The liquid medium may be selected such that one or more of the starting materials (e.g. the metal source, the amine source, and/or the carboxylate source) or product(s) formed (e.g. the metal amine and/or the metal amine carboxylate) are soluble in the liquid medium or a 0 liquid phase thereof. In various embodiments, the metal amine and/or metal amine carboxylate are soluble in the liquid medium or a liquid phase thereof. For example, the metal amine and metal amine carboxylates described in the examples below are soluble in aqueous solutions, such as the aqueous ammoniacal solution used therein. 5 The concentration of the metal source, the amine source, and the carboxylate source in the liquid medium is not limited. However, to reduce the amount of liquid medium used and increase the rate of reaction, higher concentrations may be preferred. In certain embodiments, the concentration of the metal source, the amine source, and/or the carboxylate source in the liquid medium is at least about 0.05 mol/L, for example at least 0.1, !0 0.5, 1, 1.5, or 2 mol/L.

In various embodiments where the liquid medium comprises water, the composition may comprise at least 5, 10, 20, 30, 40, 50, 60, 70, 80, or 90% water by weight of the composition, and useful ranges may be selected from any two of these values. 25

Reaction of the metal source, the amine source, and the carboxylate source may be carried out at any suitable temperature and/or pressure.

The reaction may be carried out at atmospheric pressure or pressure greater than 30 atmospheric pressure. Carrying out the reaction under pressure may advantageously enhance the rate or reaction and/or minimise loss of volatile components.

Those skilled in the art will be able to select appropriate temperatures for reaction, having regard to the nature of the starting materials and the product(s) to be formed. The 35 temperature may be selected such that the various components of the reaction mixture (for example, the amine source, liquid medium, etc.) are not evaporated during the reaction. 15 2016204205 21 Jun2016

Where a metal amine is formed in the absence of a carboxylate source, the metal amine may be formed under different reaction conditions to those used to form the metal amine carboxylate. For example, a metal source, such as copper carbonate, and an amine source, such as aqueous ammonia, may be reacted at a first temperature to form a reaction product, 5 for example a copper ammine complex; and the reaction product reacted with a carboxylate source, for example naphthenic acid, at a second temperature that may be the same as or different to the first to form the composition.

In various embodiments, the first temperature, second temperature, or temperature at which 0 the composition is formed is from about 0 to 100*0, for example from about 0 to 90, 0 to 80, 0 to 70, 0 to 60, 0 to 50, 10 to 100, 10 to 90, 10 to 80, 10 to 70, 10 to 60, 10 to 50, 20 to 100, 20 to 90, 20 to 80, 20 to 70, 20 to 60, or 20 to 50 <0. Preferably, the composition is formed by reaction at a temperature from ambient temperature (e.g. about 20 “€) to about 100 “€. 5 Reaction of the metal source, the amine source, and the carboxylate source may be carried out under any suitable atmosphere. The atmosphere used may depend on the nature of the starting materials and products to be formed.

Reaction may be carried out under an inert atmosphere, such as nitrogen or noble gas, or !0 oxidising atmosphere, such as an atmosphere of air or oxygen. For example, the reaction may be carried out under an oxidising atmosphere to oxidise a metal source, for example elemental copper. The oxidation may be carried out using a system or reaction vessel pressurised with air or oxygen (i.e. at a pressure greater than atmospheric) to enhance the rate of oxidation. Pressurisation may also mitigate egress of ammonia or amine. 25

The ratio of the metal source to the amine source, metal source to carboxylate source, and the amine source to carboxylate source depends on the nature of the metal, amine, and carboxylate. 30 Without wishing to be bound by theory, the inventor believes that the metal amine and metal amine carboxylates comprise coordination complexes. In the coordination complexes the metal is coordinated by an amino group of each of the at least one amine. In the metal amine carboxylate, it is believed that the at least one carboxylate may be present as a counter ion. For example, the inventor believes that the copper tetra-ammine complexes 35 referred to in the examples below comprise a copper +2 ion coordinated by four ammine ligands. Two aquo ligands may be present such that an octahedral complex is formed. The 16 2016204205 21 Jun2016 complex has an overall +2 charge due to the oxidation state of the copper cation, which is countered by two carboxylate anions, each having a charge of -1. A person skilled in the art will appreciate that the metal amine and metal amine carboxylate 5 can accommodate different numbers of ligands coordinated to the metal. The oxidation state of the metal can affect the number of ligands that complex can accommodate.

The oxidation state of the metal and the nature of the ligands, determine the overall charge of the coordination complex. The charge may be balanced by the presence of any suitable 0 counter ion (cation or anion) in the necessary stoichiometry. Suitable counter ions will be apparent to those skilled in the art.

Those skilled in the art will appreciate that the number of amino group(s) in an amine or carboxylate group(s) in a carboxylate may affect the ratio of the starting materials. 5

The ratio of the metal source to amine source may be such that the stoichiometric ratio of amino group(s) to metal is at least about 1:1, for example at least about 2:1,3:1, or 4:1. The amine may be provided in an amount equal to or in excess of the maximum amount of amine that can be accommodated by the metal, having regard to its oxidation state. For example, !0 a copper 2+ cation may accommodate up to 6 amine ligands (a stoichiometric ratio of metal to amine of 1:6) when in anhydrous ammonia (the amine ligands being ammonia), but in aqueous ammonia the copper 2+ cation typically accommodates only 4 amine ligands. An excess of the amine source may be used. 25 In various embodiments, the ratio of the metal source to the amine source is such that the stoichiometric ratio of amino group(s) to metal is at least about 4:1, for example at least about 5:1 or 6:1.

The ratio of metal source to carboxylate source may be such that the metal carboxylate 30 formed on decomposition of the composition comprising the metal, amine, and carboxylate is neutral (has an overall neutral charge). In such embodiments, the number of carboxylates in the metal carboxylate are sufficient to counter the cationic charge of the metal. An excess of the carboxylate source may be used. 35 In various embodiments, the ratio of metal source to carboxylate source is such that the stoichiometric ratio of carboxylate carboxylate group(s) to metal is (m x n):1, wherein m is at least 1 (for example at least 1.1, 1.2, 1.5, 2, or 3) and n is the charge of the metal cation. 17 2016204205 21 Jun2016

For example, where the metal is copper 2+ and the carboxylate is a monocarboxylate such as stearate, the ratio of carboxylate groups(s) to metal is at least 2:1.

In various embodiments, the ratio of the metal source to carboxylate source is such that the 5 stoichiometric ratio of carboxylate group(s) to metal is at least about 1:1, for example at least about 2:1,3:1, or 4:1.

The ratio of amine source to carboxylate source is typically dictated by the ratios of these starting materials with respect to the metal source. In various embodiments, the ratio of the 0 amine source to the carboxylate source is such that the stoichiometric ratio of amino group(s) to carboxylate group(s) is at least about 1:1, for example 2:1 or 3:1.

The reaction may be carried out for any suitable length of time. For example, the metal source, the amine source, and the carboxylate source may be reacted to form the metal 5 amine carboxylate until at least one of the starting materials is consumed.

The metal carboxylate may comprise any suitable metal. The metal selected will depend on the desired application for the metal carboxylate. As described herein metal carboxylates are useful in various applications. In various embodiments, the metal is a biocidal metal. I0

The metal may be a metal selected from the metals of groups 3 to 15 of the periodic table. Suitable metals include, for example, copper (e.g. Cu2+), zinc (e.g. Zn2+), cobalt (e.g. Co2+), iron (e.g. Fe2+ or Fe3+), manganese (e.g. Mn2+), antimony (e.g. Sb3+), bismuth (e.g. Bi3+), titanium (e.g. Ti4+), zirconium (e.g. Zr4+), and nickel (e.g. Ni2+) and the like. In certain 25 preferred embodiments, the metal is selected from the group consisting of copper, zinc, iron, cobalt, manganese, and nickel. Preferably, the metal is copper.

The metal may be in any suitable oxidation state. In various embodiments, the metal is selected from copper (II) or zinc (II). In various embodiments, the metal is copper (II). 30

The metal source may be selected based on the metal desired and the ability to form the composition or metal amine carboxylate on reaction with the amine source and carboxylate source. 35 The metal source may be substantially insoluble in water. In various embodiments, the metal source comprises a metal salt that is substantially insoluble in water. The water insoluble metal salt may have a solubility in water of less than about 1 x10-4 g/L. Examples of 18 2016204205 21 Jun2016 such salts include but are not limited to metal oxides, hydroxides, or carbonates, such as basic copper carbonate, malachite, azurite, copper oxide, copper hydroxide, and the like. Such salts may react with the amine source and/or carboxylate source to form metal amines and/or metal amine carboxylates soluble in a liquid medium comprising water. 5

In various embodiments, the method comprises reacting a substantially water insoluble metal source, such as a substantially water insoluble metal salt or elemental metal, and an amine source, and optionally a carboxylate source, in a liquid medium comprising water to dissolve the water insoluble metal source. For example, reaction of basic copper carbonate 0 in water with ammonia in the presence of stearic acid, as described in Example 1, leads to dissolution of substantially water insoluble basic copper carbonate as the corresponding metal amine carboxylate is formed.

In various embodiments, the metal source comprises a metal salt of a volatile organic acid, 5 such as formic or acetic acid. The volatile organic acid may be separated during the reaction, by for example evaporation, to form the composition.

In various embodiments, the metal source comprises a metal in elemental form, for example elemental copper, such as copper scrap metal. The metal source may be reacted with an !0 oxidant, optionally in the presence of the amine source and/or carboxylate source, to oxidise the metal. The oxidation may be carried using any suitable oxidant. Suitable oxidants include but are not limited to air and oxygen, as described herein. The metal source may be oxidised with an oxidant in the presence the amine to form a metal amine, which may be reacted with a carboxylate source to form the corresponding metal amine carboxylate. 25 Alternatively, the metal source may be oxidised in the presence of both the amine source and carboxylate source to form the metal amine carboxylate directly. Conveniently, as described in the examples, metallic copper may be oxidised in the presence of ammonia using air as the oxidant to provide the corresponding metal ammine. 30 The amine comprises an amino group. In various embodiments, the amine is a monoamine (i.e. comprises a single amino group).

The amine may be ammonia or an organic amine as described herein. The organic amine may be a primary, secondary or tertiary amine having, for example, 1 to 8 carbon atoms. 35

Typically, the amine is volatile, such that on decomposition of the composition it may be separated by, for example, evaporation. Preferably, the amine is ammonia. 19 2016204205 21 Jun2016

The amine source may be an amine (i.e. a free amine) or a salt thereof. Suitable amine salts include those capable of forming amines under the reaction conditions, for example ammonium salts capable of forming amine under basic conditions. 5

The amine source may be provided in any suitable form for reaction with the metal source and the carboxylate source. The amine source may be in the form of a gas or liquid. For example, in various embodiments where the amine is ammonia, the amine source may be in the form of gaseous ammonia or an aqueous solution of ammonia. Those skilled in the art 0 will appreciate that the boiling point of aqueous solutions of ammonia can vary depending on the concentration of ammonia in the solution.

The carboxylate comprises a carboxylate group. In various embodiments, the carboxylate is a monocarboxylate (i.e. a carboxylate comprising a single carboxylate group). 5

The carboxylate may be selected based on the desired application. Typically, the carboxylate is a carboxylate of a non-volatile carboxylic acid. The non-volatile carboxylic acid may have a boiling point of greater than 75,100, 125, 150, 175, 200, or 225 “€, for example. The boiling point of the carboxylic acid may be greater than that of the amine, !0 such that on decomposition the amine may be separated (e.g. by evaporation) from the composition without removing the carboxylate.

The carboxylate may be lipophilic. In various embodiments, the carboxylate is a carboxylate of a carboxylic acid that is substantially insoluble in water. The water-octanol partition 25 coefficient (log Kow) of the carboxylic acid may be at least about 1, 1.5, 1.7, 1.8, 1.9, 2.0, 2.2, or 2.4, for example at least about 1.9. For example, 2-ethyl hexanoic acid has a log P of about 2.5 and stearic acid a log P of about 8.2.

The carboxylate typically comprises at least two carbon atoms. The molecular weight of the 30 carboxylate may be at least about 75 g/mol. Preferably, the molecular weight is at least about 100, 125, or 150 g/mol.

In various embodiments, the molecular weight of the metal carboxylate is at least about 175, 200, 225, 250, 300, or 325 g/mol. For example, the molecular weight of copper(ll) 2-35 ethylhexanoate as prepared in the examples below is about 349 g/mol. 20 2016204205 21 Jun2016

In various embodiments, the carboxylate is a group of formula RC(0)0", wherein R is an organic group. A wide range of carboxylates having different organic groups are useful in the method. 5 In various embodiments, the carboxylate is a C8-20, preferably C10-16, alicyclic carboxylate, for example a naphthenate; a fatty acid, for example a C4-28, preferably C6 to 22 or C6 to 20, fatty acid such as a stearate, linoleate, or ethylhexanoate; a C15-C30, preferably C20, polycyclic alicyclic carboxylate, for example an abietate. 0 In certain embodiments, the carboxylate is a stearate, naphthenate, or 2-ethylhexanoate.

Naphthenates are carboxylates derived from naphthenic acids (e.g. CAS 1338-24-5). Naphthenic acids are mixtures of naturally occurring cycloaliphatic carboxylic acids recovered from petroleum distillates, which comprise an unspecific mixture of cyclopentyl 5 and cyclohexyl carboxylic acids. The molecular weights of the acids may range from about 120 g/mol to over 700 g/mol. The main fraction is carboxylic acids with a carbon backbone of about 9 to 20 carbons, primarily cyclic aliphatic carboxylic acids with 10 to 16 carbons. Naphthenic acids are typically recovered by caustic extraction of petroleum distillates boiling in the 200-370^ range and are commercially availab le in various grades of purity. !0

Abietates are derived from abietic acid(s) obtainable from tree rosin extracts. Abietic acid belongs to the abietane diterpene group of organic compounds derived from four isoprene units. Abietic acid can obtained in the form of a yellow resinous powder having a melting point from 172-172Ό. Pure abieitc acid may have a melting point as low as 85ΤΤ 25

The carboxylate source may be the corresponding carboxylic acid (conjugate acid) or a salt thereof. For example, in various embodiments where the carboxylate is naphthenate, the carboxylate source may be naphthenic acid or a salt thereof such as ammonium naphthenate. 30

The carboxylate source may be in the form of a liquid or solid.

The composition and the metal amine carboxylate may be decomposed by any suitable method to form the metal carboxylate. Decomposition of the metal amine carboxylate 35 comprises removal of the at least one amine (that is, all of the amine ligand(s)) from the metal amine carboxylate to form the metal carboxylate. 21 2016204205 21 Jun2016

It will be apparent to those skilled in the art the metal carboxylate formed in the methods of the present invention is substantially free (preferably completely free) of the amine. Preferably, the metal carboxylate does not comprise any of the amine. In various embodiments, the metal carboxylate consist of or consists essentially of a metal and at least 5 one carboxylate. Those skilled in the art will appreciate that a composition comprising metal carboxylate produced in accordance with the methods of the invention may however comprise trace amounts of amine, for example where the metal carboxylate is viscous or semi-solid. 0 The metal carboxylate may be substantially insoluble in water. For example, as described herein copper naphthenate is insoluble in water but soluble in diesel. In various embodiments, the metal carboxylate has a water-octanol partition coefficient (log Kow) of at least about 1.5, 1.7, 1.8, 1.9, 2.0, 2.1,2.2, 2.3, 2.4, 2.5, 2.7, or 3.0, for example at least about 2.5. 5

The stoichiometric ratio of metal to carboxylate in the metal carboxylate may be sufficient to provide a neutral compound. In various embodiments, the ratio is such that the total anionic charge provided by the one or more carboxylates in metal carboxylate is substantially equal to the cationic charge of the metal. For example, for copper stearate, the ratio of copper 2+ !0 to stearate is 1:2.

In a certain embodiments, decomposing the composition or metal amine carboxylate comprises heating, optionally under reduced pressure (for example, heating at a temperature and pressure sufficient to evaporate the amine and/or liquid medium). The 25 temperature required to remove the amine from the metal amine carboxylate may vary depending on the nature of the metal amine carboxylate.

The metal amine carboxylate may comprise two or more amines. For example, without wishing to be bound by theory, the inventor believes, as described in the examples, that 30 copper tetra-ammine complexes may be formed by reacting a source of copper and ammonia in ratios equal to or in excess of 1:4.

In such embodiments, the two or more amines may be removed from the metal amine carboxylate successively, for example with increasing temperature. For example, in the 35 copper tetra-ammine complexes described herein higher temperatures are typically required to remove the last ammine ligand than the first, second, or third ammine ligand removed from the complex. 22 2016204205 21 Jun2016

The temperature required to remove all of the amine and form the metal carboxylate varies depending on the compound. In some embodiments, the temperature required may be in excess of 15(ΤΟ. 5

In various embodiments, the metal carboxylate is prepared by decomposing the composition or metal amine carboxylate at a temperature greater than ambient temperature (e.g. about 20Ό), for example greater at least about 40, 50, 6 0, 70, 80, 90, 100, 125, or 150Ό. 0 In various embodiments, the decomposing is carried out at a temperature greater than that at which the metal source, the amine source, and carboxylate source are reacted to form the metal amine carboxylate.

In various embodiments, the reaction to form the metal amine carboxylate is carried out at 5 around ambient temperature, and the metal carboxylate is formed by decomposing the metal amine carboxylate at an elevated temperature. In some embodiments, decomposition temperatures of up to 100 Ό may be used. Higher t emperatures may be less preferred due to cost of energy. I0 In various embodiments, the decomposing may be carried out at a temperature from about 30 to 250 O, for example from about 40 to 200, 50 to 150, 50 to 125, 50 to 100, 60 to 150, 60 to 125, 60 to 100, 70 to 150, 70 to 125, 70 to 100, 80 to 150, 80 to 125, or 80 to 100Ό.

In certain embodiments where the amine is ammonia, the decomposing may be carried out at a temperature of about 70 to 100Ό, preferably 8 OTT 25

The decomposing step may comprise separating the amine (for example, by evaporation) from the composition to form the metal carboxylate. In various embodiments, the decomposing step comprises separating the amine removed from the metal amine carboxylate. In various embodiments, the amine may be separated by evaporation during 30 and/or after the decomposition. Evaporation may be carried out at any suitable temperature and pressure. In such embodiments, the amine may preferably be volatile.

The separated amine may be collected, optionally for reuse. Amine separated by evaporation may be collected by condensation. In various embodiments, the method further 35 comprises recycling the separated amine, for example by reaction with fresh metal source and optionally a carboxylate source. Advantageously, such recycling reduces the amount of waste produced by the method. 23 2016204205 21 Jun2016

The metal amine carboxylate may be in a liquid medium as described herein during the decomposing step. 5 The concentration of the metal amine carboxylate in the liquid medium is not limited.

Suitable concentrations include but are not limited to those described herein for the metal source, the amine source, and/or carboxylate source.

In various embodiments, the liquid medium may be separated from the metal carboxylate, 0 for example by evaporation at a sufficient temperature and pressure during and/or after the decomposition of the metal carboxylate.

The separated liquid medium may be collected, optionally for reuse. Liquid medium separated by evaporation may be collected by condensation. The separated liquid medium 5 may be collected together with separated amine or separately, for example by fractional distillation. In various embodiments, the method further comprises recycling the liquid medium. Advantageously, such recycling reduces the amount of waste produced by the method. !0 The temperature used may depend on the pressure at which the decomposing step is carried out. In various embodiments, the decomposing step is carried out at atmospheric pressure or under reduced pressure (i.e. under vacuum).

Carrying out the decomposing step under reduced pressure may lower the temperature 25 required to decompose the metal amine carboxylate. Carrying out the decomposing step under reduced pressure may also allow evaporation of the amine removed from the metal amine carboxylate and/or the liquid medium at lower temperatures.

The decomposing step may be carried under any suitable atmosphere, for example under an 30 atmosphere of air or an inert atmosphere, such as nitrogen.

The decomposing step may be carried out until decomposition of the metal amine carboxylate is complete or substantially complete. Those skilled in the art will appreciate that the rate of decomposition may be increased by increasing the temperature at which the 35 decomposition is carried out. 24 2016204205 21 Jun2016

The temperature and rate of heating may be controlled to ensure even heating and/or to reduce or prevent decomposition of the metal carboxylate during the decomposing step.

The metal carboxylate formed on decomposition may be, for example in the form of a liquid, 5 solution, solid, etc.

In various embodiments, the method comprises providing the metal carboxylate in the form of a solid, semisolid or neat liquid by separating, for example by evaporation, the amine and the liquid medium, if present, during and/or after the decomposing step. In certain 0 embodiments, conveniently, no further processing (e.g. purification) of the product may be required.

Those skilled in the art will appreciate that certain metal carboxylates may be insoluble in polar solvents, such as water. Accordingly, in various embodiments where an aqueous 5 liquid medium is present in the decomposing step, the metal carboxylate may separate out from the liquid medium into a separate liquid phase.

In various embodiments, decomposition of the composition comprising the metal, amine, and carboxylate provides a multiphasic composition comprising a first liquid phase comprising !0 the metal carboxylate, and a second liquid phase comprising the liquid medium or a liquid phase thereof.

The liquid phase comprising the metal carboxylate may be separated from the other liquid phase(s) to isolate the metal carboxylate. Any suitable method of separation may be used. 25

The liquid phase comprising the metal carboxylate may comprise one or more solvents in which the metal carboxylate is soluble. The solvent may be added prior to, during or after forming the metal carboxylate. The inclusion of such a solvent may assist in separating the metal carboxylate, for example the solvent may improve partitioning between different liquid 30 phases. In some embodiments, the method comprises carrying the decomposition in a liquid medium comprising such a solvent. As demonstrated in the examples, the metal carboxylates described herein may be soluble in non-polar organic solvents, such as hydrocarbons, for example diesel. 35 The solvent may be removed after separating the liquid phase comprising the metal carboxylate to provide solvent free metal carboxylate, for example in solid form or as a neat 25 2016204205 21 Jun2016 liquid. Alternatively, the liquid phase comprising the metal carboxylate may be suitable for use in the desired application without having to remove the solvent.

Advantageously, in various embodiments, the method may allow formation of the metal 5 carboxylate from the metal source, the amine source, and carboxylate source in a single reaction vessel or reactor. In such methods, the amount of plant and equipment required is reduced. Such "one-pot" methods may also reduce processing times and other manufacturing costs. 0 The method may be carried out as a batch, semi-batch or continuous process.

Heating or cooling in the method may, as required, be provided by any suitable means, for example by heat exchangers within or surrounding the reaction vessel(s). 5 In the methods described herein, the reaction mixture(s) may be mixed, for example to increase the rate of reaction, ensure even heating/cooling, and the like. Mixing may be provided by any suitable means, for example stirring with impellers, etc.

The progress of the reaction(s) described herein may be monitored by any suitable method !0 known in the art. Advantageously, the inventor has found that in certain embodiments formation of the metal carboxylate may be monitored by a change in colour. For example, as described in Example 3 below, the inventor has found that aqueous solutions of copper(ll) ammine 2-ethylhexanoate is deep blue in colour and that the corresponding metal carboxylate formed on decomposition of this complex is deep green in colour. Without 25 wishing to be bound by theory, the inventor believes that this change in colour may be due to conversion of the octahedral copper(ll) ammine complex to a water insoluble metal soap of the formula Cu(2-ethylhexanoate)2 which does not have any coordinated ammine or water ligands. 30 Removal one or more amines from a metal amine carboxylate comprising two or more amines may provide an unsaturated-metal amine carboxylate.

In various embodiments, the method comprises: providing a metal amine carboxylate comprising a metal, at least two amines, and at 35 least one carboxylate, optionally in a liquid medium; and 26 2016204205 21 Jun2016 decomposing the metal amine carboxylate to remove at least one of the at least two amines and form an unsaturated-metal amine carboxylate comprising the metal, at least one amine, and at least one carboxylate such as a metal mono-amine carboxylate. 5 Those skilled in the art will appreciate that the unsaturated-metal amine carboxylate comprises at least one amine less that the metal amine carboxylate from which it is formed.

In various embodiments, the unsaturated-metal amine carboxylate comprises one or two amine(s) (i.e. is a metal mono- or bis-amine carboxylate). 0 The term "unsaturated-metal amine carboxylate" as used herein unless indicated otherwise is intended to mean a metal amine carboxylate that is unsaturated with respect to the number of amine(s) present, having regard to the metal. That is, the number of amine(s) present in an unsaturated metal amine carboxylate is less than the maximum that could be accommodated by the metal. 5

For example, decomposition of a copper tetra-ammine carboxylate may provide a copper mono- or bis-ammine carboxylate, both of which are unsaturated with respect to the number of ammines that could be accommodated by the copper cation. !0 The unsaturated-metal amine carboxylate may be decomposed to prepare the corresponding metal carboxylate. The methods described herein contemplate decomposing both saturated and unsaturated-metal amine carboxylates.

In various embodiments, the unsaturated-metal amine carboxylate may be stable to 25 decomposition at ambient temperature. Such unsaturated-metal amine carboxylates may be isolated and optionally stored for later conversion into the metal carboxylate. This may be useful in embodiments where it is necessary or desirable to generate fresh metal carboxylate for a particular application. 30 The metal carboxylates described herein may be useful in various applications. For example, the metal carboxylates may be useful as drying agents for alkyd paints, catalysts for polyester resins, lubricants and as biocidal agents useful, for example, in the preservation of wood. Other applications will be apparent to those skilled in the art. 35 For use in certain applications, the metal carboxylate may be mobilised by for example, dissolving, suspending or dispersing the metal carboxylate in a suitable liquid medium. The 27 2016204205 21 Jun2016 liquid may comprise one or more non-polar organic solvents, such as hydrocarbons and mixtures thereof, for example diesel.

The liquid medium used and concentration of the metal carboxylate in the liquid may be 5 determined by the application. For example, for wood preservation applications, the concentration of the metal carboxylate in the liquid medium is typically sufficient to provide a predetermined standard or level of preservation. Suitable concentrations will be apparent to or can be determined by those skilled in the art.

0 EXAMPLES

The following non-limiting examples are provided to illustrate the present invention and in no way limit the scope thereof. 5 Example 1

This example describes the preparation of copper stearate from basic copper carbonate. 2.2 g (0.01 mol) Basic copper carbonate equivalent to 0.02 mol copper was added to a !0 reaction vessel. To this was added 5.7 g (0.04 mol) stearic acid plus 20 ml water. With agitation aqueous ammonia was slowly added until all the basic copper carbonate was dissolved, resulting in a deep blue solution. The copper is believed to be present as a copper tetra-ammine stearate. 25 The solution was heated to 80 “C to drive off the a mmonia, which was recovered for reuse. This resulted in a pale green soapy residue of copper stearate. Copper stearate has a copper content of about 10% by weight. The solid compound may be mobilised by adding a suitable organic solvent. 30 Since copper stearate is insoluble in water, the compound produced was dissolved in diesel. Diesel is equivalent to P9 oil, as recognised by the American Wood Preservatives Association (AWPA) as an authorised carrier for solvent soluble wood preservatives. Dissolution resulted in a green solution. 35 Example 2

This example describes the preparation of copper stearate from copper scrap metal. 28 2016204205 21 Jun2016 1.27 g Copper scrap metal equivalent to 0.02 mol copper was added to a reactor. To this was added 0.02 mol ammonium carbonate and subsequently aqueous ammonia was added sufficient to give a final mol ratio of ammonia to copper of 4:1. An excess of ammonia is 5 tolerated. Subsequently oxygen or air is introduced into the agitated mixture until the copper is oxidised to copper (2+), at which time it is believed the copper exists in solution as a copper tetra-ammine carbonate complex. An excess of ammonia was maintained to prevent the precipitation of copper carbonate, believed to result from decomposition of the copper tetra-ammine carbonate complex to basic copper carbonate. To this was added 5.7 g (0.04 0 mol) stearic acid plus 20 ml water. This resulted in a deep blue solution. The copper species is believed to be present as a copper tetra-ammine stearate complex.

This solution was heated until all the ammonia and water had been driven off and recovered for reuse. This resulted in a blue green soapy residue of copper stearate. 5

Example 3

This example describes the preparation of copper 2-ethylhexanoate from basic copper carbonate. !0 2.2 g (0.01 mol) Basic copper carbonate equivalent to 0.02 mol copper was added to a reaction vessel. To this was added 2.9 g (0.04 mol) 2-ethylhexanoic acid plus 20 ml water, giving a pale green opaque suspension. With agitation aqueous ammonia was slowly added until all the basic copper carbonate was dissolved, resulting in a deep blue solution. The 25 copper species was believed to be present as a copper tetra-ammine 2-ethylhexanoate.

The solution was heated to 80 Ό to remove the ammo nia and water, which were recovered for reuse. 30 A deep green oily residue of copper 2-ethylhexanoate was formed with a copper content of about 18% by weight. The residue is relatively immobile but can be cut with a suitable organic solvent such as kerosene, white spirits, diesel or the like.

As in example 1 this product is soluble in diesel, producing a clear green solution. 35

Example 4 29 2016204205 21 Jun2016

This example describes the preparation of copper 2-ethylhexanoate from copper scrap metal. 1.27 g Copper scrap metal equivalent to 0.02 mol copper was added to a reactor. To this 5 was added 0.02 mol ammonium carbonate and subsequently aqueous ammonia was added sufficient to give a final mol ratio of ammonia to copper of 4:1. An excess of ammonia is tolerated. Subsequently oxygen or air is introduced into the agitated mixture until the copper is oxidised to copper (2+), at which time it is believed the copper exists in solution as copper tetra-ammine carbonate complex. An excess of ammonia was maintained to prevent the 0 precipitation of copper carbonate. To this was added 2.9 g (0.04 mol) 2-ethylhexanoic acid plus 20 ml water. This resulted in a deep blue solution. The copper species was believed to be present as a copper tetra-ammine 2-ethylhexanoate complex.

This solution was heated until all the ammonia and water had been driven off and recovered 5 for reuse. This resulted in a deep green oily residue of copper 2-ethylhexanoate.

As in example 1 this product is soluble in diesel, producing a clear green solution.

Example 5 !0

This example describes the preparation of copper naphthenate from basic copper carbonate. 2.2 g (0.01 mol) Basic copper carbonate equivalent to 0.02 mol copper was added to a reaction vessel. To this was added 3.6 g (0.04 mol) naphthenic acid with an average 25 molecular weight of 180 g/mol plus 20 ml water. With agitation aqueous ammonia was slowly added until all the basic copper carbonate was dissolved, resulting in a deep blue solution. The copper species was believed to be present as a copper tetra-ammine naphthenate.

The solution was heated to 80 Ό to drive off the a mmonia and water, which were recovered 30 for reuse. This resulted in a deep green oily residue of copper naphthenate.

As in example 1 this product is soluble in diesel, producing a clear green solution.

Example 6 35

This example describes the preparation of copper naphthenate from copper scrap metal. 30 2016204205 21 Jun2016 1.27 g Copper scrap equivalent to 0.02 mol copper was added to a reactor. To this was added 0.02 mol ammonium carbonate and subsequently aqueous ammonia was added sufficient to give a final mol ratio of ammonia to copper of 4:1. An excess of ammonia is tolerated. Subsequently oxygen or air is introduced into the agitated mixture until the copper 5 is oxidised to copper (2+), at which time it is believed the copper exists in solution as copper tetra-ammine carbonate complex. An excess of ammonia was maintained to prevent the precipitation of copper carbonate. To this was added 3.6 g (0.04 mol) naphthenic acid plus 20 ml water. This resulted in a deep blue solution. The copper species was believed to be present as a copper tetra-ammine naphthenate complex. 0

This solution was heated until all the ammonia and water had been driven off and recovered for reuse. This resulted in a deep green oily residue of copper naphthenate.

As in example 1 this product is soluble in diesel, producing a clear green solution. 5

Example 7

This example describes an alternative preparation of copper 2-ethylhexanoate from copper scrap metal. !0

Copper metal as scrap electrical wiring equivalent to copper 0.01 mol was added to a reactor and 0.02 mol 2-ethylhexanoic acid added. Sufficient ammonia as an aqueous solution was added to solubilise the 2-ethylhexanoic acid. Further ammonia was added, so that the total amount of ammonia in the reactor was slightly in excess of 0.04 mol. With continuous 25 agitation air or oxygen is introduced into the fluid until the copper metal was oxidised. After oxidation, it is believed the copper existed in solution as a copper tetra-ammine 2-ethylhexanoate complex. The complex was then converted to copper 2-ethylhexanoate by heating to drive off the water and ammonia as described in the previous examples. 30 As in example 1 this product is soluble in diesel, producing a clear green solution.

The oxidation and dissolution of the copper in this example is fast, the copper readily oxidising to yield the copper tetra-ammine 2-ethylhexanoate. Whilst the absolute stoichiometry is not critical, those skilled in the art will understand that for complete 35 dissolution of the copper scrap the mole ratio of copper to amine to acid is preferably less than or equal to 1:4:2, for example 1:6:3 or 1:8:4. Dissolution of the copper scrap can be fast and quantitative. 31 2016204205 21 Jun2016

In the above described oxidation the system can be pressurised with air or oxygen to enhance the reaction rate and to mitigate egress of ammonia or amine.

Those skilled in the art will be aware that ammonia (the amine) and water (the liquid 5 medium) can be separated conveniently by vacuum distillation and optionally recovered for further use. By using vacuum distillation it may be possible to lower the boiling point of the aqueous phase to, for example, around 50 Ό or lowe r (depending on the level of vacuum used), rather than 100 Ό at ambient pressure. 0 Those skilled in the art will be aware that addition of a non-polar solvent with a boiling point greater than the aqueous phase, such as diesel or kerosene, may allow removal of the aqueous phase while retaining the metal carboxylate in solution. Diesel as used in the above examples has a boiling point typically above 200¾ and kerosene has a boiling point above 140¾. 5

Whilst it is facile to prepare copper carboxylates according the methods described in the examples above, those skilled in the art will appreciate that other sources of copper may be used. For example, malachite or azurite, which are typically cheaper than basic copper carbonate or copper metal, may be used as the source of copper. In such embodiments, !0 copper carbonate may be eluted from the ore into and/or so as to form a copper tetra-ammine complex solution, which may then be filtered prior to formation of the copper carboxylate. 25 In the examples, the removal of ammonia from the complexes is accompanied by a change in colour, for example removal of ammonia from the deep blue solution comprising the copper tetra-ammine carboxylate complex resulted in a deep green copper carboxylate. A composition containing the metal carboxylate compounds described herein may be 30 prepared at a specific concentration of copper. Those skilled in the art will be aware that one or more solvents can be added to obtain the desired concentration.

Whilst the methods described in the examples use heating to separate water and ammonia for reuse, those skilled in the art will be aware that one or more organic solvents may be 35 added to the copper tetra-ammine carboxylate complex prior to heating to form a biphasic mixture comprising an organic phase, which may be separated from the aqueous phase. 32 2016204205 21 Jun2016

The copper tetra-ammine carboxylate in the organic phase can then be heated to liberate ammonia from the complex.

Alternatively, in the methods described in the examples, one or more water immiscible 5 organic solvents may be included in the reaction mixture as part of the liquid medium during formation of the copper tetra-amine carboxylate complex such that the liquid medium is biphasic and the complex partitions into the organic phase as it forms.

The methods described in examples 1,3 and 5 may require several pieces of plant, but can 0 be simpler to carry out than certain prior art methods for preparing metal carboxylates.

Advantageously, the methods described in examples 2, 4, 6 and 7 can be carried out using a single reactor and have a very rapid time of production. 5 Further, the methods may allow waste streams to be minimised. All components produced in the methods other than the desired metal carboxylate product can be recycled in the process, for example water and ammonia. Thus not only can the cost of plant and equipment and the time of production minimised, but also the costs of any starting/processing materials required in the methods. !0

In the methods of this invention, inexpensive raw materials such as scrap copper metal or impure copper ores may be used, thus providing significant cost savings. By selecting appropriate feed stocks and processing parameters, high purity product streams without byproducts may readily be obtained. 25

Additionally, the method may allow users to eliminate or reduce potential health, safety, and environment issues associated with certain existing methods for preparing metal carboxylates. 30 It is not the intention to limit the scope of the invention to the abovementioned examples only. As would be appreciated by a skilled person in the art, many variations are possible without departing from the scope of the invention. 35

Claims (33)

1. A method for preparing a metal carboxylate, the method comprising: providing a composition comprising a metal, an amine, and a carboxylate, optionally in a liquid medium; and decomposing the composition to form a metal carboxylate comprising the metal and at least one carboxylate.

2. The method of claim 1, wherein providing the composition comprises providing a metal source, an amine source, and a carboxylate source; and reacting the metal source, the amine source, and the carboxylate source in any order, optionally in a liquid medium, to form the composition.

3. The method of claim 1 or 2, wherein decomposing the composition comprises heating the composition, optionally under reduced pressure.

4. The method of any one of claims 1-3, wherein decomposing the composition comprises separating the amine from the composition.

5. The method of any one of claims 1-4, wherein providing the composition comprises providing a metal amine carboxylate comprising a metal, at least one amine, and at least one carboxylate.

6. The method of claim 5, wherein decomposing the composition comprises decomposing the metal amine carboxylate to remove the at least one amine and form the metal carboxylate.

7. The method of claim 5 or 6, wherein providing the metal amine carboxylate comprises providing a metal amine comprising a metal and at least one amine; and reacting the metal amine with a carboxylate source, optionally in a liquid medium, to form the metal amine carboxylate.

8. The method of claim 7, wherein providing the metal amine comprises reacting a metal source and an amine source, optionally in a liquid medium, to form the metal amine.

9. The method of any one of claims 6-8, wherein decomposing the metal amine carboxylate to form the metal carboxylate comprises heating the metal amine carboxylate, optionally under reduced pressure, to remove the at least one amine.

10. The method of any one of claims 6-8, wherein the method comprises separating the amine removed from the metal amine carboxylate from the metal carboxylate.

11. The method of any one of claims 1-10, wherein the metal is selected from the metals of groups 3 to 15 of the periodic table.

12. The method of any one of claims 1-11, wherein the metal is selected from the group consisting of copper, zinc, iron, cobalt, manganese, antimony, bismuth, titanium, zirconium, nickel.

13. The method of any one of claims 1-12, wherein the metal is copper.

14. The method of any one of claims 1-13, wherein the amine is selected from the group consisting of ammonia and organic amines, or a combination of any two or more thereof.

15. The method of any one of claims 1-14, wherein the amine is volatile.

16. The method of any one of claims 1-15, wherein the amine is ammonia.

17. The method of any one of claims 1-16, wherein the carboxylate is a carboxylate of a non-volatile carboxylic acid.

18. The method of any one of claims 1-17, wherein the carboxylate is a carboxylate of a substantially water insoluble carboxylic acid.

19. The method of any one of claims 1-18, wherein the carboxylate is a stearate, naphthenate, or 2-ethylhexanoate.

20. The method of any one of claims 1-19, wherein the liquid medium comprises water, a polar organic solvent, a non-polar organic solvent, a water miscible organic solvent, a water immiscible solvent, or a combination of any two or more thereof.

21. The method of any one of claims 1-20, wherein the liquid medium comprises water, methanol, ethanol, propanol, butanol, or a combination of any two or more thereof.

22. The method of any one of claims 1-21, wherein the liquid medium comprises water.

23. The method of any one of claims 1-22, wherein the method comprises separating the liquid medium from the composition comprising the metal, amine, and carboxylate or from the metal carboxylate.

24. The method any one of claims 4-23, wherein the method comprises collecting and optionally recycling the separated amine and/or liquid medium.

25. The method of any one of claims 2-24, wherein the metal source comprises a substantially water insoluble metal salt, a volatile organic acid metal salt, elemental metal, or a combination of any two or more thereof.

26. The method of any one of claims 2-25, wherein the metal source comprises a metal oxide, hydroxide, or carbonate, a formic acid or acetic acid metal salt, an elemental metal, or a combination of any two or more thereof.

27. The method of any one of claims 2-26, wherein the metal source is a substantially water insoluble metal salt or elemental metal.

28. The method of any one of claims 2-27, wherein the method comprises reacting the metal source and an oxidant, optionally in the presence of the amine source and/or carboxylate source, to oxidise the metal.

29. The method of claim 28, wherein the metal source is elemental metal.

30. The method of claim 28 or 29, wherein the oxidant is air or oxygen.

31. The method of any one of claims 1-30, wherein decomposing the composition comprising the metal, amine, and carboxylate provides a multiphasic composition comprising a first liquid phase comprising the metal carboxylate, and a second liquid phase comprising the liquid medium or a liquid phase thereof.

32. The method of any one of claims 4-31, wherein the amine and/or liquid medium is separated by evaporation at a temperature and pressure sufficient to evaporate the amine and/or liquid medium.

33. A metal carboxylate comprising a metal and at least one carboxylate prepared by a method according to any one of the preceding claims.