GB2630680A

GB2630680A - Use, method and composition

Info

Publication number: GB2630680A
Application number: GB2406496.6A
Authority: GB
Inventors: Ruth Shore Emma
Original assignee: Innospec Ltd
Current assignee: Innospec Ltd
Priority date: 2023-05-11
Filing date: 2024-05-09
Publication date: 2024-12-04
Also published as: GB202307012D0; GB202406496D0; WO2024231684A1

Abstract

Use, method and composition comprising a compound for preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii). The optionally substituted polycarboxylic acid may comprise an optionally substituted succinic acid or succinic anhydride which may be substituted with an alkyl, alkenyl, alkaryl or aralkyl group. The salt of a polycarboxylic acid or the anhydride thereof or the salt of the reaction product may comprise an alkali metal salt and/or an amine salt. The composition may be used to prevent tarnishing of metal in automatic dishwashing.

Description

Use, method and composition

Field of the Invention

The present invention relates to the use of particular compounds to prevent or reduce corrosion and/or staining of metallic surfaces during cleaning processes and methods and compositions related thereto. In particular, the invention relates to the use of said compounds to prevent or reduce corrosion and/or staining of metallic surfaces during an automatic dishwashing process.

Background

Corrosion is a significant problem in industrial and domestic settings. The process of corrosion may involve the conversion of a metal into an oxide, hydroxide, carbonate or sulfide and it may affect any metallic surface of an industrial or domestic equipment or appliance. Corrosion may cause pitting, crevices or stress cracks within the metallic surface. Corrosion may ultimately lead to failure of the equipment, which must then be repaired or replaced.

Many species may be responsible for corrosion of a metal. Corrosion may especially be caused by acidic species like sulfides, basic species, oxygen and water present in the air or dissolved within a fluid in contact with the metallic surface.

Staining is another problem which may affect metallic surfaces of industrial or domestic equipment. The process of staining may involve the deposition of a substance onto a metallic surface, or the oxidation of the metal surface to form a layer of metal oxide. While staining does not usually lead to equipment failure, it is aesthetically undesirable.

For example, the equipment used in cleaning processes (either to carry out the cleaning process or as the object of the cleaning process) is typically exposed to various substances during the course of its lifetime. The equipment is in contact with air containing oxygen and moisture and so the equipment can experience corrosion. Furthermore, during a cleaning process the equipment may come into contact with a cleaning agent, often at elevated temperatures, which may cause corrosion or staining of metallic surfaces of the equipment.

Corrosion and staining is a known issue in dishwashing, especially automatic dishwashing, applications. For example corrosion and staining may occur on the items being washed and metallic surfaces of the dishwasher.

There remains a need for compounds which can prevent or reduce corrosion and/or staining of metallic surfaces during cleaning processes, especially automatic dishwashing processes. Additionally, these compounds would advantageously have a low aquatic toxicity and be biodegradable.

Summary

According to a first aspect of the present invention, there is provided the use of a compound for preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii).

According to a second aspect of the present invention, there is provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii); and contacting the at least a portion of the metallic surface with a cleaning agent.

According to a third aspect of the present invention, there is provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii); 35 and (b) a builder.

According to a fourth aspect of the present invention, there is provided the use of a compound for preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii).

According to a fifth aspect of the present invention, there is provided the use of a compound for preventing or reducing staining of a metallic surface, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii).

According to a sixth aspect of the present invention, there is provided a method of preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii).

According to a seventh aspect of the present invention, there is provided a method of preventing or reducing staining of a metallic surface, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii).

Detailed Description

Unless otherwise stated, the following terms used in the specification and claims have the meanings set out below.

As used herein, the term "hydrocarbyl" substituent or group is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include: (i) hydrocarbon groups, that is, aliphatic (which may be saturated or unsaturated, linear or branched, e.g. alkyl or alkenyl or alkynyl), alicyclic (e.g. cycloalkyl, cycloalkenyl), and aromatic substituents, combinations thereof (e.g. alicyclic-and aromatic-substituted aliphatic substituents, such as aralkyl, aliphatic-and aromatic-substituted alicyclic substituents, and aliphatic-and alicyclic-substituted aromatic substituents such as alkaryl), as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g. two substituents together form a ring); (ii) substituted hydrocarbon groups, that is, substituents containing non-hydrocarbon groups (e.g. halo (especially chloro and fluoro), hydroxy, alkoxy, keto, acyl, cyano, mercapto, alkylmercapto, amino, alkylamino, nitro, nitroso, and sulfoxy); (iii) hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this invention, contain other than carbon in a ring or chain otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. In general, no more than two, preferably no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, there will be no non-hydrocarbon substituents in the hydrocarbyl group.

By "optionally substituted" groups we mean that the particular groups are substituted or unsubstituted. Suitable substituents may include hydroxyl, oxo, alkoxy (such as Ci to C4 alkoxy), amino, halo (especially fluoro and chloro), trifluoromethyl, trifluoromethoxy, cyano, alkyl (such as Ci to C6 alkyl), alkenyl (such as C2 to Cs alkenyl), alkynyl (such as C2 to Cs alkynyl) and aryl (such as phenyl) groups.

In preferred embodiments, hydrocarbyl groups herein are unsubstituted hydrocarbyl groups, i.e. consisting essentially of or consisting of hydrogen atoms and carbon atoms.

The terms "alkyl", "alkenyl" and "alkynyl" include both straight and branched chain alkyl, alkenyl and alkynyl groups respectively.

The term "aryl" as used herein relates to an organic moiety derived from an aromatic hydrocarbon by removal of one hydrogen, and includes any monocyclic, bicyclic or polycyclic carbon ring of up to 7 members in each ring, wherein at least one ring is aromatic.

The term "heteroaryl" as used herein relates to an organic moiety derived from a heterocyclic aromatic group or heteroarene by removal of one hydrogen, and includes any monocyclic, bicyclic or polycyclic ring of up to 7 members in each ring, wherein at least one ring is aromatic. The heteroaryl group consists of hydrogen atoms, carbon atoms, and at least one heteroatom, such as sulfur, oxygen, and/or nitrogen.

The term "aralkyl" as used herein relates to alkyl moieties substituted with an aryl group, wherein the aryl group is an organic moiety derived from an aromatic hydrocarbon by removal of one hydrogen, and includes any monocyclic, bicyclic or polycyclic carbon ring of up to 7 members in each ring, wherein at least one ring is aromatic. An example of an aralkyl group is a benzyl group. The term "alkaryl" as used herein refers to aryl moieties substituted with an alkyl group.

The term "heteroarylalkyl" as used herein relates to alkyl moieties substituted with a heteroaryl group. The term "alkylheteroaryl" as used herein refers to heteroaryl moieties substituted with an alkyl group.

By a salt of an anhydride compound we mean to refer to a salt that is formed following hydrolysis of the anhydride group(s).

By "corrosion" we mean the deterioration of a material as a result of chemical interactions between the material and the surrounding environment, which may be caused by exposure of the material to corrosive substances. By "tarnishing" we mean a specific type of corrosion where a surface layer forms due to a chemical reaction, for example with oxidants or sulfur containing species.

By "staining" we mean discolouration of a material as a result of physical or chemical interactions between the material and the surrounding environment, which may be caused by exposure of the material to one or more of the following: oxidizing agents, dyes such as tannins, bleaching agents, undissolved salts; or a source of sulfide such as onions or eggs.

By "preventing" or "reducing" corrosion and/or staining of a surface we mean preventing or reducing corrosion and/or staining of at least a portion of said surface. In some embodiments, corrosion and/or staining may be prevented or reduced on the entirety of said surface.

By "metallic surface" we mean a surface which comprises a metal (i.e. as a single element metal or an alloy). Suitable metals include aluminium, iron, steel, copper, zinc, silver, tin, and/or gold (especially steel (such as stainless steel), silver and/or gold). The metallic surface may comprise an alloy comprising at least one of aluminium, iron, copper, zinc, silver, tin, and/or gold. An example of a suitable alloy is bronze or steel.

By "cleaning process" we mean a process during which a surface, for example the surface of equipment, is cleaned. The surface may be cleaned by removing dirt or grease therefrom. The cleaning process typically involves contact of said surface with a cleaning agent. The surface being cleaned may be metallic or non-metallic. However, when the surface being cleaned is non-metallic, a metallic surface is suitably present during at least a portion of the cleaning process, for example as part of cleaning equipment.

By "washing machine" we mean an appliance which is used to wash laundry.

By "auto dishwash" or "automatic dishwashing" we mean a machine washing process (i.e. of kitchen utensils, tableware and/or cookware).

By "manual dishwash" or "manual dishwashing" we mean a cleaning process (i.e. of kitchen utensils, tableware and/or cookware) carried out without the use of a machine.

By "kitchen utensil" we mean tools (other than cookware) typically used in the preparation of food and/or beverages, such as spoons, kitchen knives, forks, ladles, spatulas, whisks, sieves, and colanders (preferably tools typically used in the preparation of food or beverages, such as spoons, kitchen knives, forks, ladles, spatulas, whisks, sieves, and colanders).

By "tableware" we mean equipment used to consume food or beverages, such as forks, knives, spoons, plates, bowls, drinking glasses, cups and/or mugs.

By "cookware" we mean equipment used in the preparation of food or beverages, such as pots, pans, baking trays and roasting dishes.

By "domestic cleaning process" we mean a cleaning process carried out in a domestic setting, such as in a household, and not on an industrial scale. A "domestic cleaning process" may alternatively be referred to herein as "home care". Home care may involve the cleaning of surfaces around the home (in particular hard, non-textile surfaces), the cleaning of clothes (laundry) and the cleaning of kitchen utensils, tableware and cookware (dishwashing).

By "industrial cleaning process" we mean a cleaning process which is carried out in an industrial setting and suitably on an industrial scale, for example in factories or warehouses. Industrial cleaning processes may involve the use of more corrosive cleaning agents and/or higher temperatures than domestic cleaning processes.

By "institutional cleaning process" we mean a cleaning process which is carried out in an institutional setting, such as in schools, hospitals, offices and other commercial premises.

As used in the specification and the appended claims, the singular forms "a", "an," and "the" include both singular and plural referents unless the context clearly dictates otherwise.

Throughout this specification, the term "comprising" or "comprises" means including the component(s) specified but not to the exclusion of the presence of other components. The term "consisting essentially of or "consists essentially of means including the components specified but excluding other components except for components added for a purpose other than achieving the technical effect of the invention. The term "consisting of or "consists of means including the components specified but excluding other components.

Whenever appropriate, depending upon the context, the use of the term "comprises" or "comprising" may also be taken to include the meaning "consists essentially of or "consisting essentially of', and also may also be taken to include the meaning "consists of or "consisting of'.

As used herein, unless otherwise expressly specified, all numbers such as those expressing values, ranges, amounts of percentages may be read as if prefaced by the word "about", even if the term does not expressly appear.

The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1, 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each exemplary embodiment of the invention, as set out herein are also applicable to any other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or embodiment of the invention as interchangeable and combinable between different aspects of the invention.

As used herein, the term "and/or," when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a list is described as comprising group A, B, and/or C, the list can comprise A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination. References to a "combination" or a "mixture" of two or more listed items are intended to exclude the use of one of the listed items alone. For example, by a combination or a mixture of A, B and/or C we mean that the list can comprise A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination (but that A alone; B alone; and C alone are excluded).

According to a first aspect of the present invention there is provided the use of a compound for preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii).

According to a preferred embodiment of the first aspect of the present invention there may be provided the use of a compound for preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, wherein the compound comprises (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof.

According to a preferred embodiment of the first aspect of the present invention there may be provided the use of a compound for preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, wherein the compound comprises (H) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the first aspect of the present invention there may be provided the use of a compound for preventing or reducing corrosion and/orstaining of a metallic surface in a cleaning process, wherein the compound comprises (iii) a combination of (i) and (ii): (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a second aspect of the present invention there is provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii); and contacting the at least a portion of the metallic surface with a cleaning agent.

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and contacting the at least a portion of the metallic surface with a cleaning agent.

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; and contacting the at least a portion of the metallic surface with a cleaning agent.

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (iii) a combination of (i) and (ii): (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; and contacting the at least a portion of the metallic surface with a cleaning agent.

The inventor has found that compounds as defined herein are surprisingly effective for preventing or reducing corrosion and/or staining of metallic surfaces during cleaning processes. For example, the compounds as defined herein may be surprisingly effective for preventing or reducing corrosion of metallic surfaces during cleaning processes, in particular cleaning processes carried out in equipment such as automatic dishwashers or washing machines. The present inventor has found certain derivatives of optionally substituted polycarboxylic acids or anhydrides thereof that are effective at preventing or reducing corrosion and/or staining of metallic, especially silver, surfaces in automatic dishwashing processes.

Reducing corrosion has the advantage that equipment (i.e. comprising a metallic surface) may be used for longer periods of time without needing to maintain, repair or replace the equipment or components thereof. Since the equipment cannot be used during maintenance, repair or replacement, reducing corrosion also reduces equipment downtime. Furthermore, the lustre or appearance of the equipment being cleaned (such as tableware) may advantageously be maintained.

Preferred features of the first and second aspects of the present invention will now be described. Any feature may apply to any other aspect as appropriate. For example, the definition of the compound may apply to the third, fourth, fifth, sixth and seventh aspects.

Where reference is made to an or the anhydride thereof, this is intended to mean an anhydride of any of the polycarboxylic acid(s) listed in the text preceding this phrase. For example, the phrase "octenyl succinic acid, dodecenyl succinic acid or an anhydride thereof' means to include octenyl succinic acid, octenyl succinic anhydride, dodecenyl succinic acid and dodecenyl succinic anhydride.

References herein to a polycarboxylic acid are intended to refer to compounds comprising at least two carboxylic acid groups. The optionally substituted polycarboxylic acid or the anhydride thereof may comprise an optionally substituted tricarboxylic acid or tetracarboxylic acid or an anhydride thereof Examples of suitable tricarboxylic acids include citric acid and trimesic acid. An example of a suitable tetracarboxylic acid is pyromellitic acid.

The optionally substituted polycarboxylic acid or the anhydride thereof may comprise an optionally substituted dicarboxylic acid or an anhydride thereof Examples of suitable dicarboxylic acids include 3,3'-thiodipropanoic acid, iminodiacetic acid, itaconic acid, tartaric acid, maleic acid, oxalic acid, malonic acid, succinic acid, glutamic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, phthalic acid and sebacic acid. The optionally substituted dicarboxylic acid may be selected from oxalic acid, malonic acid, succinic acid, glutamic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, phthalic acid and sebacic acid, preferably from succinic acid and phthalic acid. Preferably, the optionally substituted dicarboxylic acid or the anhydride thereof comprises an optionally substituted succinic acid or an optionally substituted succinic anhydride.

The optionally substituted dicarboxylic acid or the anhydride thereof may be selected from octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid and phthalic acid or an anhydride thereof. Preferably, the optionally substituted dicarboxylic acid or the anhydride thereof may be selected from octenyl succinic acid, dodecenyl succinic acid and phthalic acid or an anhydride thereof The optionally substituted polycarboxylic acid or the anhydride thereof is suitably substituted with a hydrocarbyl group. The optionally substituted polycarboxylic acid or the anhydride thereof is suitably substituted with an alkyl, alkenyl, alkynyl, alkaryl or aralkyl group, preferably an alkyl, alkenyl, alkaryl or aralkyl group, more preferably an alkyl or alkenyl group.

The alkyl or alkenyl group suitably has from 2 to 36 carbon atoms, such as from 4 to 22 carbon atoms, for example from 6 to 18 carbon atoms.

Preferably, the optionally substituted polycarboxylic acid or the anhydride thereof is substituted with an alkenyl group. The alkenyl group suitably has from 2 to 36 carbon atoms, such as from 4 to 22 carbon atoms, for example from 6 to 18 or from 8 to 12 carbon atoms. The alkenyl group may suitably be decenyl, octenyl (such as 2-octen-1-y1) or dodecenyl, preferably 2-octen-1-ylor dodecenyl. For example, the optionally substituted polycarboxylic acid or the anhydride thereof may comprise decenyl succinic acid, 2-octen-1-yl succinic acid or dodecenyl succinic acid, preferably 2-octen-1-yl succinic acid or dodecenyl succinic acid.

In some embodiments the alkyl or alkenyl group is a polyisobutenyl group, preferably having a number average molecular weight of from 100 to 5000, preferably from 200 to 2000, suitably from 220 to 1300, for example from 240 to 1000.

The optionally substituted polycarboxylic acid or the anhydride thereof may comprise a hydrocarbyl substituted polycarboxylic acid or an anhydride thereof. Suitably the optionally substituted polycarboxylic acid or the anhydride thereof comprises a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof. For example, the optionally substituted polycarboxylic acid or the anhydride thereof may comprise an alkyl or alkenyl (more preferably alkenyl) substituted dicarboxylic acid or an anhydride thereof. Preferably the optionally substituted polycarboxylic acid or the anhydride thereof comprises an alkyl or alkenyl substituted succinic acid or an anhydride thereof. Most preferably, the optionally substituted polycarboxylic acid or the anhydride thereof comprises 2-octen-1-yl succinic acid, dodecenyl succinic acid or an anhydride thereof. Suitably, the optionally substituted polycarboxylic acid or the anhydride thereof comprises 2-octen-1-ylsuccinic anhydride or dodecenyl succinic anhydride.

The salt of the optionally substituted polycarboxylic acid or the anhydride thereof or the salt of the reaction product suitably comprises an alkali metal salt and/or an amine salt. References herein to salts thus refer to salts of the optionally substituted polycarboxylic acid or an anhydride thereof 0) and/orto salts of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine (ii).

Suitable alkali metal salts include sodium salts and potassium salts. Sodium salts are preferred. Alkali metal salts are suitably prepared by neutralising the optionally substituted polycarboxylic acid or the anhydride thereof with an alkali metal hydroxide.

Suitable amine salts are salts formed by any suitable amine. Suitable amines used to form the salt include ammonia, primary, secondary and tertiary amines, and quaternary ammonium compounds.

In some embodiments the amine used to form the salt is ammonia. By "ammonium salt" we mean a salt formed from ammonia.

In some embodiments the amine used to form the salt is a quaternary ammonium compound.

In some preferred embodiments the amine used to form the salt is an aralkylamino, alkarylamino, alkylamino and/or hydroxyalkyl amino compound.

In some preferred embodiments the amine used to form the salt is an alkylamino and/or hydroxyalkyl amino compound. The amine is suitably substituted with one to three alkyl or hydroxyalkyl groups having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms.

The amine may be an alkylamine, a hydroxyalkylamine (such as 1-aminopropan-2-ol or 2-amino- 2-methyl-1-propanol), a dialkylamine, a hydroxyalkyl alkyl amine, a dihydroxyalkylamine, a trialkylamine, a dialkylhydroxyalkylamine, a dihydroxyalkylalkylamine or a trihydroxyalkylamine (such as triethanolamine). There are many different compounds of this type and these will be known to the person skilled in the art. In some embodiments the amine used to form the salt is a cyclic amine.

In some embodiments the amine salt comprises a primary amine salt. Suitable primary amines used to form a primary amine salt include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, 2-aminobutanol, ethanolamine, cyclohexylamine, aminopropanediol, isopropanolamine (i.e. 1-aminopropan-2-ol), mixed isopropanolamines, aminomethyl propanol (i.e. 2-amino-2-methyl-1-propanol), 2-(2-aminoethoxy)ethanol, aminoethyl propanediol, aminomethyl propanediol, aminoethyl propanol, tromethamine, 1-phenylethylamine, benzyl amine, and amino acids., such as methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, 2-aminobutanol, ethanolamine, cyclohexylamine, aminopropanediol, isopropanolamine, mixed isopropanolamines, tromethamine, 1-phenylethylamine and benzyl amine. Suitable amino acids include aspartic acid, glutamic acid, glutamine, asparagine, serine, threonine, tyrosine, histidine, tryptophan, lysine, and arginine, preferably lysine and arginine.

In some embodiments the amine salt comprises a secondary amine salt.

Suitable secondary amine compounds used to form a secondary amine salt include dimethylamine, N,N-methylethylamine, N,N-methylpropylamine, N,N-methylbutylamine, diethylamine, N,N-ethylpropylamine, N,N-ethylbutylamine, dipropylamine, N,N-propylbutylamine, dibutylamine, N,N-butylmethylamine, N,N-butylethylamine, N,Nbutylpropylamine, N,N-methylmethanolamine, N,N-methylethanolamine, diethanolamine, N,Nmethylpropanolamine, dipropanolamine, N,N-methylbutanolamine, dibutanolamine, N,Nethylmethanolamine, N,N-ethylethanolamine, N,N-ethylpropanolamine, N,N-ethylbutanolamine, N,N-propylmethanolamine, N,N-propylethanolamine, N,N-propylpropanolamine, N,N- propylbutanolamine, N,N-butylmethanolamine, N,N-butylethanolamine, N,N-butylpropanolamine, N,N-butylbutanolamine, diisopropylamine, diisopropanolamine, morpholine, hexamethylenetetramine (hexamine), N-methylbenzylamine, N-ethylbenzylamine, n-propylbenzylamine, dibenzylamine, hydroxyethylbenzylamine, polyethylene polyamines such as: diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine and mixtures and isomers thereof.

Preferably the amine salt comprises a tertiary amine salt.

Suitable tertiary amine compounds used to form a tertiary amine salt include trimethylamine, N,N-dimethylethylamine, N,N-dimethylpropylamine, N,N-dimethylbutylamine, triethylamine, N,N-diethylmethylamine, N,N-diethylpropylamine, N,N-diethylbutylamine, tripropylamine, N,Ndipropylmethylamine, N,N-dipropylethylamine, N,N-dipropylbutylamine, tributylamine, N,N- dibutylmethylamine, N,N-dibutylethylamine, N,N-dibutylpropylamine, N,N-dimethylmethanolamine, methyldimethanolamine, N,N-dimethylethanolamine, methyldiethanolamine, N,N-dimethylpropanolamine, methyldipropanolamine, N,N-dimethylbutanolamine, methyldibutanolamine, N,N-diethylmethanolamine, ethyldimethanolamine, N,N-diethylethanolamine, ethyldiethanolamine, N,N-diethylpropanolamine, ethyldipropanolamine, N,N-diethylbutanolamine, ethyldibutanolamine, 30 N,N-dipropylmethanolamine, propyldimethanolamine, N,N-dipropylethanolamine, propyldiethanolamine, N,N-dipropylpropanolamine, propyldipropanolamine, N,N-d ipropylbutanolamine, propyldibutanolamine, N,N-dibutylmethanolamine, butyldimethanolamine, N,N-dibutylethanolamine, butyldiethanolamine, N,N-dibutylpropanolamine, butyldipropanolamine, N,N-dibutylbutanolamine, butyldibutanolamine, trimethanolamine, triethanolamine, tripropanolamine, tributanolamine, diethylhexylamine, dimethyltolylamine, bis-hydroxyethyl tromethamine, dimethylamino methylpropanol, dimethyl isopropanolamine, dimethyl monoethanolamine (MEA), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), hydroxyethyl methyl tolyl amine, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dipropylbenzylamine, N,N-dihydroxyethylbenzylamine, triisopropanolamine, N,N-dimethyl- 1,3-diaminopropane, N,N-diethyl-1,3-diaminopropane, N,N-dimethylethylenediamine, N,Ndiethylethylenediamine, N,N-dibutylethylenediamine, N,N-bis(2-hydroxyethyl)taurine, and mixtures and isomers thereof Preferably the amine used to form the salt comprises at least one hydroxyalkyl substituent.

Suitable amines of this type include but are not limited to triethanolamine, trimethanolamine, N,N-dimethylaminopropanol, N,N-dimethylaminoethanol, N,N-diethylaminopropanol, isopropanolamine, 2-amino-2-methyl-1-propanol, N,N-diethylaminoethanol, N,N- diethylaminobutanol, N,N,NLtrimeth yl-N'-h yd roxyeth yl-bisa mi noethyleth er; N,N-bis(3- dimethylaminopropyl)-N-isopropanolamine; N-(3-dimethylaminopropyl)-N,N- diisopropanolamine; 2-(2-dimethylaminoethoxy)ethanol, N,N,N'-trimethylaminoethylethanolamine, and N,N-bis(2-hydroxyethyl)taurine, such as triethanolamine, trimethanolamine, N,N-dimethylaminopropanol, N,N-dimethylaminoethanol, N,N-diethylaminopropanol, isopropanolamine, N,N-diethylaminoethanol, N,N-diethylaminobutanol, N,N, N'-tri meth yl-N'-h yd roxyeth yl-bisa mi n oethylethe r; N,N-bis(3-dimethylaminopropyI)-N- isopropanolamine; N-(3-dimethylaminopropyI)-N,N-diisopropanolamine; 2-(2-dimethylaminoethoxy)ethanol, N,N,N'-trimethylaminoethylethanolamine, and N,N-bis(2-hydroxyethyl)taurine.

Preferably the amine salt comprises an ammonium salt, a primary amine salt, or a tertiary amine salt, such as an ammonium salt or a tertiary amine salt. Preferably, the amine used to form the salt is selected from ammonia, isopropanolamine, aminomethyl propanol, triethanolamine, and N,N-bis(2-hydroxyethyl)taurine, such as selected from ammonia, triethanolamine and N,N-bis(2-hydroxyethyl)taurine.

The salt of the optionally substituted polycarboxylic acid or the anhydride thereof may be a partial salt or a full salt of the acid/anhydride. By "partial salt" we mean that the compound comprises at least one free carboxylic acid group and by "full salt" we mean that all acid groups in the compound are in the form of a salt. For example, the compound may comprise a mono salt or di salt of a dicarboxylic acid or an anhydride thereof.

In some embodiments the compound comprises a di alkali metal salt of a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof. Preferably the compound comprises a disodium or dipotassium salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. More preferably the compound comprises a disodium salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof, such as 2-octen-1-yl succinic acid, dodecenyl succinic acid or an anhydride thereof.

In some embodiments the compound comprises a mono amine salt of a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof. Suitably the compound comprises a mono ammonium, primary, tertiary or quaternary amine salt (such as a mono ammonium, tertiary or quaternary amine salt) of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a mono ammonium salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a mono quaternary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a mono tertiary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a mono primary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. Preferably the compound comprises a mono ammonium salt, primary amine salt or tertiary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. Preferably the compound comprises a mono ammonium salt or tertiary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. More preferably the compound comprises a mono ammonium salt, a mono isopropanolamine salt, a mono aminomethyl propanol salt, a mono triethanolamine salt or a mono N,N-bis(2-hydroxyethyl)taurine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof, such as 2-octen-1-yl succinic acid, decenyl succinic acid, dodecenyl succinic acid or an anhydride thereof. More preferably the compound comprises a mono ammonium salt, a mono triethanolamine salt or a mono N,N-bis(2-hydroxyethyl)taurine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof, such as 2-octen-1-yl succinic acid, decenyl succinic acid, dodecenyl succinic acid or an anhydride thereof.

In some embodiments the compound comprises a bis amine salt of a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof. Suitably the compound comprises a bis ammonium, primary, tertiary or quaternary amine salt (such as a bis ammonium, tertiary or quaternary amine salt) of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a bis ammonium salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a bis quaternary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a bis tertiary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a bis primary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. Preferably the compound comprises a bis ammonium salt, a bis isopropanolamine salt, a bis aminomethyl propanol salt, a bis triethanolamine salt or a bis N,N-bis(2-hydroxyethyl)taurine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof, such as 2-octen-1-yl succinic acid, decenyl succinic acid, dodecenyl succinic acid or an anhydride thereof. Preferably the compound comprises a bis ammonium salt, a bis triethanolamine salt or a bis N,N-bis(2-hydroxyethyl)taurine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof, such as 2-octen-1-yl succinic acid, decenyl succinic acid, dodecenyl succinic acid or an anhydride thereof.

In some embodiments the compound comprises a mixed alkali metal/amine salt of a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof. Suitably, the compound comprises a mono sodium mono amine salt or mono potassium mono amine salt of a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof. Preferably, the compound comprises a mono sodium mono amine salt of a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof. In some embodiments the compound comprises a mono sodium mono ammonium salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a mono sodium mono tertiary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a mono sodium mono quaternary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof. In some embodiments the compound comprises a mono sodium mono primary amine salt of an alkyl or alkenyl substituted succinic acid or an anhydride thereof.

In some embodiments of the first and second aspects of the present invention, the compound may comprise the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

In some embodiments of the first and second aspects of the present invention, the compound may comprise the reaction product of reactants consisting essentially, or consisting, of an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

The compound may comprise the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol, or a salt of the reaction product.

Any suitable alcohol may be used to form the reaction product. The alcohol may comprise from 1 to 40 carbon atoms, such as from 5 to 35 carbon atoms, such as from 6 to 30 carbon atoms, for example from 6 to 20 carbon atoms.

The alcohol may comprise a monohydric alcohol or a polyhydric alcohol. A suitable polyhydric alcohol may have from 2 to 4 hydroxy groups.

The alcohol may be optionally substituted, for example optionally substituted by one or more substituent selected from an alkyl, alkenyl, aryl, heteroaryl, aralkyl, heteroarylalkyl, alkaryl and alkylheteroaryl group (for example optionally substituted by one or more substituent selected from an alkyl, alkenyl, aralkyl and alkaryl group).

Suitable alcohols substituted by an aryl, heteroaryl, aralkyl, heteroarylalkyl, alkaryl or alkylheteroaryl group for use to form the reaction product include 1-or 2-phenyl ethanol, 3-or 4-pyridinyl methanol, naphthalene methanol, benzyl alcohol (optionally wherein the benzyl group is substituted, for example by an alkyl group), and furfuryl alcohol. Preferably, the alcohol substituted by an aryl, heteroaryl, aralkyl, heteroarylalkyl, alkaryl or alkylheteroaryl group comprises furfuryl alcohol or benzyl alcohol.

Suitable monohydric alcohols for use to form the reaction product include methanol, ethanol, propanol, isopropanol, benzyl alcohol, dodecanol, tetradecanol, butanol, 2-butanol, isobutanol, octanol, 2-ethylhexanol, hexanol, cyclohexanol, cyclooctanol, 2-propylheptanol, 2-ethyl-1butanol, furfuryl alcohol and isopropanol.

The polyhydric alcohol may suitably have 2 hydroxy groups. Suitably the polyhydric alcohol comprises an alkylene glycol or a polyalkylene glycol. Preferably the polyhydric alcohol comprises a polyalkylene glycol.

The alkylene glycol may be selected from ethylene glycol, propylene glycol, 1,3-butanediol 1,4-butanediol, 1,6-hexanediol, or 2-ethyl-1,3-hexanediol. The alkylene glycol is suitably selected from ethylene glycol, propylene glycol, 1,3-butanediol or 1,4-butanediol.

The polyalkylene glycol is suitably selected from polyethylene glycol, polypropylene glycol or polybutylene glycol, or copolymers thereof. Suitable copolymers of polyalkylene glycols include copolymers of ethylene glycol and propylene glycol and copolymers of ethylene glycol and butylene glycol. The polyalkylene glycol is suitably polyethylene glycol or polypropylene glycol. Preferably the polyalkylene glycol is polyethylene glycol.

The polyhydric alcohol may have a number average molecular weight of from 60 to 6000, such as from 80 to 3000, such as from 100 to 2000, preferably from 120 to 1500, more preferably from 150 to 1200, more preferably from 170 to 1000, even more preferably from 190 to 850.

The skilled person would be familiar with standard techniques to measure number average molecular weight, such as by Vapor pressure osmometry, End-group titration, Proton NMR, Boiling point elevation, Freezing depression (cryoscopy), and GPC (Gel Permeation Chromatography).

In some embodiments the number average molecular weight of the polyhydric alcohol is from 60 to 370, suitably from 110 to 320, for example from 190 to 210.

In some embodiments the number average molecular weight of the polyhydric alcohol is from 200 to 650, suitably from 300 to 550, for example from 400 to 450.

In some embodiments the number average molecular weight of the polyhydric alcohol is from 400 to 950, suitably from 500 to 840, for example from 570 to 630.

In some embodiments the number average molecular weight of the polyhydric alcohol is from 700 to 1300, suitably from 800 to 1200, for example from 900 to 1100.

In some embodiments the polyalkylene glycol comprises polyethylene glycol having a number average molecular weight of from 60 to 370, preferably from 190 to 210, or from 400 to 950, preferably from 570 to 630.

In some embodiments the polyalkylene glycol may be a polyethylene glycol having a number average molecular weight of 200. This may be referred to as PEG 200.

In some embodiments the polyalkylene glycol may be a polyethylene glycol having a number average molecular weight of 600. This may be referred to as PEG 600.

In some embodiments the polyalkylene glycol may be a polyethylene glycol having a number average molecular weight of 1000. This may be referred to as PEG 1000.

In some embodiments the polyalkylene glycol may be a polypropylene glycol having a number average molecular weight of 200 to 650, preferably from 400 to 450, for example 425. Polypropylene glycol having a number average molecular weight of 425 may be referred to as PPG 425.

The polyhydric alcohol used to form the reaction product may have more than 2 hydroxy groups, such as 3, 4, 5 or 6 (for example 3 or 4) hydroxy groups. For example the polyhydric alcohol may be glycerol, pentaerythritol, trimethylolpropane, sorbitol or mannitol.

The alcohol may comprise a hydroxyalkyl amino compound. The amine is suitably substituted with one to three hydroxyalkyl groups having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms. The amine may be a hydroxyalkylamine, a hydroxyalkyl alkyl amine, a dihydroxyalkylamine, a dialkylhydroxyalkylamine, a dihydroxyalkylalkylamine or a trihydroxyalkylamine. Suitable amines of this type include but are not limited to monoethanolamine, N,N-methylmethanolamine, N,N-methylethanolamine, diethanolamine, N,N-methylpropanolamine, dipropanolamine, N,N-methylbutanolamine, dibutanolamine, N,Nethylmethanolamine, N,N-ethylethanolamine, N,N-ethylpropanolamine, N,N-ethylbutanolamine, N,N-propylmethanolamine, N,N-propylethanolamine, N,N-propylpropanolamine, N,N- propylbutanolamine, N,N-butylmethanolamine, N,N-butylethanolamine, N,N-butylpropanolamine, N,N-butylbutanolamine, 2-(2-aminoethoxy)ethanol, aminoethyl propanediol, aminomethyl propanediol, aminoethyl propanol, aminomethyl propanol, diisopropanolamine, triethanolamine, trimethanolamine, N,N-dimethylaminopropanol, N,Ndimethylaminoethanol, N,N-diethylaminopropanol, isopropanolamine, N,N-diethylaminoethanol, N,N-diethylaminobutanol, and N,N,N'-trimethyl-N'-hydroxyethyl-bisaminoethylether; N,N-bis(3- dimethylaminopropy1)-N-isopropanolamine; N-(3-dimethylaminopropyl)-N,N- diisopropanolamine; 2-(2-dimethylaminoethoxy)ethanol, N,N,N'-trimethylaminoethylethanolamine, N-butyldiethanolamine, and N,N-bis(2-hydroxyethyl)taurine.

In some embodiments, the alcohol is selected from n-propanol, 1-hexanol, 1-octanol, 2-ethylhexanol, dodecanol, benzyl alcohol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, monoethanolamine, diethanolamine, triethanolamine, N-butyldiethanolamine, furfuryl alcohol, polyethylene glycol having a number average molecular weight of 200, 600 or 1000, or polypropylene glycol having a number average molecular weight of 425. Preferably, the alcohol is selected from dodecanol, monoethanolamine, diethanolamine, furfuryl alcohol, and PEG 200.

Preferably the acid/anhydride and the alcohol are reacted in a molar ratio of from 10:1 to 1:10, preferably from 5:1 to 1:5, more preferably from 2.1:1 to 1:2.1, for example from 1.1:1 to 1:1.1.

The reaction product of reactants comprising the acid/anhydride and the alcohol may comprise: (a) a mono ester or a salt thereof; (b) a diester; (c) a bis ester or a salt thereof; (d) a mixed ester/amide; or (e) a mixture of (a), (b), (c) and/or (d).

Preferably, the reaction product of reactants comprising the acid/anhydride and the alcohol comprises: (a) a mono ester or a salt thereof.

By "mono ester" we mean a reaction product formed by 1 acid/anhydride molecule reacting with 1 alcohol moiety. By "diester" we mean a reaction product formed by 1 acid/anhydride molecule reacting with 2 alcohol moieties. By "bis ester" we mean a reaction product formed by 2 acid/anhydride molecules reacting with 2 alcohol moieties situated on the same molecule (e.g. a polyhydric alcohol). By "mixed ester/amide" we mean a reaction product formed by 1 acid/anhydride molecule reacting with 1 alcohol moiety and 1 amine moiety.

Typically, the reaction product of reactants comprising the acid/anhydride and the alcohol comprises a mono ester and/or a diester. Typically, the reaction product of reactants comprising the acid/anhydride and a polyhydric alcohol comprises a mono ester, a diester, and/or a bis ester. Persons skilled in the art will appreciate that such reaction products typically comprise a mixture of reaction products, i.e. a mixture of mono, di and bis esters. For example, when a reaction is intended to form a mono-ester product, the product so formed may additionally comprise a diester or bis ester product and vice versa. The reaction product may comprise any mixture of isomers such as regioisomers. The reaction product may further comprise unreacted reactants and/or reaction by-products.

In some embodiments the acid/anhydride and the alcohol are reacted in a molar ratio of from 1.5:1 to 1:1.5, such as from 1.3:1 to 1:1.3, for example 1:1.1 to 1.1:1, for example 1:1.

In some embodiments the acid/anhydride and the alcohol are reacted in a molar ratio of from 1.5:1 to 2.5:1, such as from 1.7:1 to 2.3:1, for example 2:1. Preferably the alcohol comprises a polyhydric alcohol.

The salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol is suitably an alkali metal salt, preferably a sodium or potassium salt, more preferably a sodium salt.

The salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol is suitably an ammonium salt or a tertiary amine salt, preferably wherein the tertiary amine comprises at least one hydroxyalkyl substituent, more preferably wherein the tertiary amine comprises triethanolamine or N,N-bis(2-hydroxyethyl)taurine.

In some embodiments the compound comprises a salt (such as a sodium salt) of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and an alcohol selected from hexanol, PPG 425, PEG 200, benzyl alcohol, dodecanol, monoethanolamine, diethanolamine, PEG 600 and furfuryl alcohol. Preferably, the alcohol is selected from dodecanol, monoethanolamine, diethanolamine, furfuryl alcohol, and PEG 200.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and an alcohol selected from n-propanol, 1-hexanol, 1-octanol, 2-ethylhexanol, dodecanol, benzyl alcohol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, monoethanolamine, diethanolamine, triethanolamine, furfuryl alcohol, and N-butyldiethanolamine, wherein the acid/anhydride and the alcohol are reacted in a molar ratio of from 1.1:1 to 1:1.1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and an alcohol selected from 1-octanol, dodecanol, monoethanolamine, diethanolamine, triethanolamine, and furfuryl alcohol, wherein the acid/anhydride and the alcohol are reacted in a molar ratio of 1:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polyalkylene glycol, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of from 1.1:1 to 1:1.1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 60 to 370, such as from 190 to 210, for example 200, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 1:1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 200 to 650, such as from 400 to 450, for example 425, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 1:1.

Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 400 to 950, such as from 570 to 630, for example 600, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 1:1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 700 to 1300, such as from 900 to 1100, for example 1000, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 1:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polyethylene glycol, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of from 1.1:1 to 1:1.1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyethylene glycol having a number average molecular weight of 200, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of 1:1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyethylene glycol having a number average molecular weight of 600, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of 1:1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyethylene glycol having a number average molecular weight of 1000, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of 1:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polypropylene glycol, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of from 1.1:1 to 1:1.1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polypropylene glycol having a number average molecular weight of 425, wherein the acid/anhydride and the polypropylene glycol are reacted in a molar ratio of 1:1.

In some embodiments the compound comprises the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polyalkylene glycol, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of from 1.5:1 to 2.5:1. Preferably the compound comprises the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 60 to 370, such as from 190 to 210, for example 200, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 2:1. Preferably the compound comprises the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 400 to 950, such as from 570 to 630, for example 600, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 2:1.

In some embodiments the compound comprises the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polyethylene glycol, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of from 1.5:1 to 2.5:1. Preferably the compound comprises the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyethylene glycol having a number average molecular weight of 600, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of 2:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polyalkylene glycol, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of from 1.5:1 to 2.5:1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 60 to 370, such as from 190 to 210, for example 200, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 2:1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyalkylene glycol having a number average molecular weight of from 400 to 950, such as from 570 to 630, for example 600, wherein the acid/anhydride and the polyalkylene glycol are reacted in a molar ratio of 2:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polyethylene glycol, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of from 1.5:1 to 2.5:1. Preferably the compound comprises a sodium or potassium (preferably sodium) salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and a polyethylene glycol having a number average molecular weight of 200, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of 2:1.

The compound may comprise the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an amine, or a salt of the reaction product.

Any suitable amine may be used to form the reaction product. Suitably the amine for use to form the reaction product comprises a primary or secondary amine.

In some preferred embodiments the amine for use to form the reaction product is an alkylamino and/or hydroxyalkyl amino compound. The amine is suitably substituted with one or two alkyl or hydroxyalkyl groups having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms.

The amine may be an alkylamine, a hydroxyalkylamine, a dialkylamine, a hydroxyalkyl alkyl amine, or a dihydroxyalkylamine. There are many different compounds of this type and these will be known to the person skilled in the art. In some embodiments the amine is a cyclic amine.

In some embodiments the amine for use to form the reaction product comprises a primary amine. Suitable primary amines include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, 2-aminobutanol, ethanolamine, cyclohexylamine, aminopropanediol, isopropanolamine, mixed isopropanolamines, aminomethyl propanol, tromethamine, 3-dimethylaminopropylamine, benzyl amine, and amino acids, such as methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, 2-aminobutanol, ethanolamine, cyclohexylamine, aminopropanediol, isopropanolamine, mixed isopropanolamines, tromethamine, 3-dimethylaminopropylamine and benzyl amine. Suitable amino acids include aspartic acid, glutamic acid, glutamine, asparagine, serine, threonine, tyrosine, histidine, tryptophan, lysine, and arginine, preferably lysine and arginine. The primary amine may be selected from methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, 2-aminobutanol, ethanolamine, cyclohexylamine, aminopropanediol, isopropanolamine, mixed isopropanolamines, aminomethyl propanol, tromethamine, benzyl amine, lysine, and arginine, such as from methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, 2-aminobutanol, ethanolamine, cyclohexylamine, aminopropanediol, isopropanolamine, mixed isopropanolamines, tromethamine and benzyl amine.

Preferably the amine for use to form the reaction product comprises a secondary amine.

Suitable secondary amine compounds for use to form the reaction product include dimethylamine, N,N-methylethylamine, N,N-methylpropylamine, N,N-methylbutylamine, diethylamine, N,N-ethylpropylamine, N,N-ethylbutylamine, dipropylamine, N,N- propylbutylamine, dibutylamine, N,N-butylmethylamine, N,N-butylethylamine, N,Nbutylpropylamine, N,N-methylmethanolamine, N,N-methylethanolamine, diethanolamine, N,N-methylpropanolamine, dipropanolamine, N,N-methylbutanolamine, dibutanolamine, N,Nethylmethanolamine, N,N-ethylethanolamine, N,N-ethylpropanolamine, N,N-ethylbutanolamine, N,N-propylmethanolamine, N,N-propylethanolamine, N,N-propylpropanolamine, N,N- propylbutanolamine, N,N-butylmethanolamine, N,N-butylethanolamine, N,N-butylpropanolamine, N,N-butylbutanolamine, 2-(2-aminoethoxy)ethanol, aminoethyl propanediol, aminomethyl propanediol, aminoethyl propanol, diisopropylamine, diisopropanolamine, morpholine, N-methylbenzylamine, N-ethylbenzylamine, n-propylbenzylamine, dibenzylamine, hydroxyethylbenzylamine, polyethylene polyamines such as: diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine and mixtures and isomers thereof.

In some embodiments, the amine is selected from propylamine, octylamine, 3-dimethylaminopropylamine, monoethanolamine, diethanolamine, benzyl amine, lysine, and arginine, such as from propylamine, octylamine, 3-dimethylaminopropylamine, monoethanolamine, diethanolamine and benzyl amine. Preferably, the amine is selected from monoethanolamine, diethanolamine, benzyl amine, lysine, and arginine, such as from monoethanolamine, diethanolamine and benzyl amine.

Suitably the amine for use to form the reaction product is a primary or secondary amine substituted with at least one hydroxyalkyl group. Persons skilled in the art would understand that the reaction product of reactants comprising a primary or secondary amine substituted with at least one hydroxyalkyl group and an acid/anhydride may comprise a mixture of primarily amide reaction products with a minor amount of the ester reaction product. Preferably the amine for use to form the reaction product comprises a primary or secondary amine comprising at least one hydroxyalkyl substituent, such as monoethanolamine or diethanolamine.

Preferably the acid/anhydride and the amine are reacted in a molar ratio of from 10:1 to 1:10, preferably from 5:1 to 1:5, more preferably from 2:1 to 1:2, for example from 1.5:1 to 1:1.5.

In some embodiments the acid/anhydride and the amine are reacted in a molar ratio of from 1.5:1 to 1:1.5, such as from 1.3:1 to 1:1.3, for example 1:1.

The reaction product of reactants comprising the acid/anhydride and the alcohol may comprise: (a) a mono amide or a salt thereof; (b) a diamide; (c) a bis amide or a salt thereof; (d) a mixed ester/amide; (e) a mixture of (a), (b), (c) and/or (d).

Preferably, the reaction product of reactants comprising the acid/anhydride and the alcohol comprises: (a) a mono amide or a salt thereof.

By "mono amide" we mean a reaction product formed by 1 acid/anhydride molecule reacting with 1 amine moiety. By "diamide" we mean a reaction product formed by 1 acid/anhydride molecule reacting with 2 amine moieties. By "bis amide" we mean a reaction product formed by 2 acid/anhydride molecules reacting with 2 amine moieties situated on the same molecule (e.g. a polyamine). By "mixed ester/amide" we mean a reaction product formed by 1 acid/anhydride molecule reacting with 1 alcohol moiety and 1 amine moiety.

Typically, the reaction product of reactants comprising the acid/anhydride and the amine comprises a mono amide and/or a diamide. Typically, the reaction product of reactants comprising the acid/anhydride and a polyamine (such as a polyethylene polyamine) comprises a mono amide, a diamide, and/or a bis amide. Persons skilled in the art will appreciate that such reaction products typically comprise a mixture of reaction products, i.e. a mixture of mono, di and bis amides. For example, when a reaction is intended to form a mono amide product, the product so formed may additionally comprise a diamide or bis amide product and vice versa.

The reaction product may comprise any mixture of isomers such as regioisomers. The reaction product may further comprise unreacted reactants and/or reaction by-products.

In some embodiments the acid/anhydride and the amine are reacted in a molar ratio of from 1.5:1 to 1:1.5, such as from 1.3:1 to 1:1.3, for example 1:1.1 to 1.1:1, for example 1:1.

In some embodiments the acid/anhydride and the amine are reacted in a molar ratio of from 1.5:1 to 2.5:1, such as from 1.7:1 to 2.3:1, for example 2:1. Preferably the amine comprises a polyamine, such as a polyethylene polyamine.

In some embodiments the acid/anhydride and the amine are reacted in a molar ratio of from 1:1.5 to 1:2.5, such as from 1:1.7 to 1:2.3, for example 1:2.

The salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an amine is suitably an alkali metal salt, preferably a sodium or potassium salt, more preferably a sodium salt. The salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an amine is suitably an amine salt, preferably a primary or secondary amine salt. Preferably, the amine used to form the salt is the same as the amine reacted with the optionally substituted polycarboxylic acid or anhydride thereof. Thus, the salt of the reaction product may be an amine salt of a monoamide.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a primary or secondary amine, wherein the acid/anhydride and the primary or secondary amine are reacted in a molar ratio of from 1.5:1 to 1:1.5. Preferably the compound comprises a sodium salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and an amine selected from propylamine, octylamine, 3dimethylaminopropylamine, monoethanolamine, diethanolamine, benzyl amine, lysine, and arginine (such as an amine selected from propylamine, octylamine, 3-dimethylaminopropylamine, monoethanolamine, diethanolamine, and benzyl amine), wherein the acid/anhydride and the amine are reacted in a molar ratio of 1:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a primary or secondary amine, wherein the acid/anhydride and the primary or secondary amine are reacted in a molar ratio of from 1:1.5 to 1:2.5. Preferably the compound comprises an amine salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and an amine selected from propylamine, octylamine, 3-dimethylaminopropylamine, monoethanolamine, diethanolamine, benzyl amine, lysine, and arginine, wherein the acid/anhydride and the amine are reacted in a molar ratio of 1:2. Suitably, the amine used to form the salt is the same as the amine reacted with the alkyl or alkenyl substituted succinic acid or anhydride thereof.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and an amine selected from monoethanolamine, diethanolamine, and benzyl amine, wherein the acid/anhydride and the amine are reacted in a molar ratio of from 1.5:1 to 1:1.5. Preferably the compound comprises a sodium salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and an amine selected from monoethanolamine, diethanolamine, and benzyl amine, wherein the acid/anhydride and the amine are reacted in a molar ratio of 1:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and an amino acid, wherein the acid/anhydride and the amino acid are reacted in a molar ratio of from 1:1.5 to 1:2.5. Suitable amino acids include aspartic acid, glutamic acid, glutamine, asparagine, serine, threonine, tyrosine, histidine, tryptophan, lysine, and arginine, preferably lysine and arginine. Preferably the compound comprises an amine salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and an amine selected from lysine and arginine, wherein the acid/anhydride and the amine are reacted in a molar ratio of 1:2. Suitably, the amine used to form the salt is the same as the amine reacted with the alkyl or alkenyl substituted succinic acid or anhydride thereof.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a dihydroxyalkylamine, wherein the acid/anhydride and the dihydroxyalkylamine are reacted in a molar ratio of from 1.5:1 to 1:1.5. Preferably the compound comprises a sodium salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and diethanolamine, wherein the acid/anhydride and the diethanolamine are reacted in a molar ratio of 1:1.

In some embodiments the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a dihydroxyalkylamine, wherein the acid/anhydride and the dihydroxyalkylamine are reacted in a molar ratio of from 1:1.5 to 1:2.5. Preferably the compound comprises an amine salt of the reaction product of reactants comprising an alkyl or alkenyl substituted succinic acid or an anhydride thereof and diethanolamine, wherein the acid/anhydride and the diethanolamine are reacted in a molar ratio of 1:2. Suitably, diethanolamine is used to form the salt.

In some embodiments, the compound comprising (ii) a reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product, may comprise: (a) a mono ester or a salt thereof; (b) a diester; (c) a bis ester or a salt thereof; (d) a mono amide or a salt thereof; (e) a diamide; (t) a bis amide or a salt thereof; (g) a mixed ester/amide; or (h) a mixture of (a), (b), (c), (d), (e), (f), and/or (g).

Preferably, the compound comprising (ii) a reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product, comprises: (a) a mono ester or a salt thereof; (d) a mono amide or a salt thereof; or (h) a mixture of (a) and (d).

In a preferred embodiment, the compound comprises: (i) an alkali metal or amine salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a polyhydric alcohol and/or a primary or secondary amine (such as a secondary amine), or a salt of the reaction product; or (iii) a combination of (i) and (ii).

The compound may comprise the reaction product of reactants consisting essentially, or consisting of, an optionally substituted polycarboxylic acid or an anhydride thereof and a polyhydric alcohol and/or a primary or secondary amine (such as a secondary amine), or a salt of the reaction product.

In a preferred embodiment, the alcohol and/or the amine is selected from dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, and arginine, such as from dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine and diethanolamine.

The compound suitably comprises a compound of formula (I): R1 x R2 (I) wherein X is a linking group; R1 is 0-M+, 0(R30)nR4, or NR5R6; and R2 is OH, O-W, 0(R30),R4, or NR5R6; wherein each W is independently a cation; each R3 is independently an optionally substituted alkylene group; each R4 is independently hydrogen or an optionally substituted hydrocarbyl group; each R5 is independently hydrogen or an optionally substituted hydrocarbyl group; each R6 is independently an optionally substituted hydrocarbyl group; each n is independently 0 or a positive integer, provided that n is not 0 when R4 is hydrogen.

X in formula (I) is preferably an optionally substituted hydrocarbylene group. Preferably X is an optionally substituted alkylene or arylene group. Preferably X is a substituted alkylene group or In some embodiments, Xis a phenylene group, preferably a 1,2-phenylene group.

Suitably X is an alkyl or alkenyl substituted alkylene group.

Preferably X is an alkenyl substituted alkylene group.

Preferably X is an alkenyl substituted alkylene group wherein the alkylene group has from 1 to 10, preferably from 1 to 6, suitably from 1 to 4, preferably 2 or 3, and most preferably 2 carbon atoms in the alkylene chain.

In some preferred embodiments X is CH2CHR or CHRCH2 wherein R is an alkyl, alkenyl or alkynyl group. R may be an alkyl or alkenyl group. such as an alkyl or alkenyl group having from 6 to 18, for example from 8 to 12 carbon atoms. Preferably R is an alkenyl group, for example having from 6 to 18, for example from 8 to 12 carbon atoms. Preferably R is an octenyl group, a decenyl group, or a dodecenyl group.

The compound may comprise a compound of formula (IA) or (IB): (IA) (I B) wherein each of R1, R2 and R is as defined herein.

M+ is suitably an alkali metal cation or an ammonium cation. Suitable alkali metal cations include sodium and potassium. Sodium is preferred.

The ammonium cation may have the formula R7R8R9R10-N+ wherein each of R7, R8, R9 and R1° is independently hydrogen, an alkyl group, an aralkyl group, an alkaryl group, a hydroxyalkyl group, a sulfoalkyl group, or the residue of an amino acid, such as wherein each of R7, R8, R9 and R1° is independently hydrogen, an alkyl group, an aralkyl group, an alkaryl group, a hydroxyalkyl group, or a sulfoalkyl group. Suitable residues of amino acids include residues of aspartic acid, glutamic acid, glutamine, asparagine, serine, threonine, tyrosine, histidine, tryptophan, lysine, and arginine, preferably lysine and arginine. Each of R7, R8, R9 and R1° may be the same or different. Suitably each of R7, R8, R9 and R19 is independently selected from hydrogen, an alkyl, hydroxyalkyl, or sulfoalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, or the residue of an amino acid, such as from hydrogen and an alkyl, hydroxyalkyl, or sulfoalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms. Each of R7, R8, R9 and R19 may be independently selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, sulfomethyl, sulfoethyl, sulfopropyl, sulfobutyl, sulfopentyl, sulfohexyl, the residue of lysine, the residue of arginine, and isomers thereof, such as from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, sulfomethyl, sulfoethyl, sulfopropyl, sulfobutyl, sulfopentyl, sulfohexyl, and isomers thereof Suitably each of R7, R°, R° and Rl° are hydrogen; or R7 is an alkyl group, a hydroxyalkyl group, or a sulfoalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, or the residue of an amino acid and each of R8, R9 and R1° are hydrogen; or R1° is hydrogen and each of R7, R8 and R9 is independently an alkyl group, a hydroxyalkyl group, or a sulfoalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms. Suitably each of R7, R8, R9 and R1° are hydrogen or R19 is hydrogen and each of R', R8 and R9 is independently an alkyl group, a hydroxyalkyl group, or a sulfoalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms. Preferably each of R7, R8, R9 and R1° are hydrogen; or R7 is a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxypropyl or hydroxybutyl, or the residue of lysine or arginine, and each of R8, R° and R1° are hydrogen; or R10 is hydrogen, R7 and R8 are a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxyethyl, and R9 is a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxyethyl, or a sulfoalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as sulfoethyl. Preferably each of R7, R8, R° and R1° are hydrogen or R19 is hydrogen, R7 and R8 are a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxyethyl, and R9 is a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxyethyl, or a sulfoalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as sulfoethyl. Preferably R7 and R8 are the same. In especially preferred embodiments, R7 is hydroxypropyl, hydroxybutyl, the residue of lysine, or the residue of arginine, and each of R8, R9 and R19 are hydrogen; or R1° is hydrogen, R7 and R8 are hydroxyethyl, and R° is hydroxyethyl or sulfoethyl. In especially preferred embodiments, R19 is hydrogen, R' and R8 are hydroxyethyl, and R9 is hydroxyethyl or sulfoethyl.

R3 is an optionally substituted alkylene group. R3 may be straight chained or branched.

Preferably R3 is an optionally substituted alkylene group having from 1 to 50 carbon atoms, preferably from 1 to 40 carbon atoms, preferably from 1 to 30 carbon atoms, more preferably from 1 to 20 carbon atoms, suitably from 1 to 10 carbon atoms, for example from 2 to 6 or from 2 to 4 carbon atoms.

Preferably R3 is an unsubstituted alkylene group.

Preferably R3 is an unsubstituted alkylene group having from 1 to 50 carbon atoms, preferably from 1 to 20, more preferably from 1 to 10, suitably from 2 to 6, for example from 2 to 4 carbon atoms.

Suitably R3 may be an ethylene, propylene, butylene, pentylene, or hexylene group. When R3 has more than 2 carbon atoms any isomer may be present. Preferably R3 is an ethylene or a propylene group, most preferably an ethylene group.

In some embodiments in which n is 1, R3 may be a group of formula (CH2)x wherein x is from 2 to 12, preferably from 2 to 6.

R3 may comprise a mixture of isomers. For example when R3 is propylene, the polyhydric alcohol may include moieties -CH2CH(CH3)-and -CH(CH3)CH2-in any order within the chain.

R3 may comprise a mixture of different groups for example ethylene, propylene or butylene units.

Block copolymer units are preferred in such embodiments.

R3 is preferably an ethylene, propylene or butylene group. R3 may be an n-propylene or nbutylene group or an isopropylene or isobutylene group. For example R3 may be -CH2CH2-, -CH2CH(CH3)-, -CH2C(CH3)2, -CH(CH3)CH(CH3)-or -CH2CH(CH2CH3)-.

Preferably R3 is ethylene or propylene. More preferably R3 is -CH2CH2-or -CH(CH3)CH2-. Most preferably R3 is -CH2CH2-.

Suitably n is from 0 to 30, preferably from 0 to 20, such as from 1 to 16. n is not 0 when R4 is hydrogen.

In some embodiments n is at least 1, such as greater than 1. Preferably n is from 2 to 30, preferably from 2 to 20, more preferably from 4 to 20, preferably from 4 to 14.

The group represented by (R30)n suitably has a number average molecular weight of from 60 to 6000, such as from 80 to 3000, such as from 100 to 2000, preferably from 120 to 1500, more preferably from 150 to 1200, more preferably from 170 to 1000, even more preferably from 190 to 850.

In some embodiments the number average molecular weight of (R30)n is from 60 to 370, suitably from 110 to 320, for example from 190 to 210.

In some embodiments the number average molecular weight of (R30)n is from 200 to 650, suitably from 300 to 550, for example from 400 to 450, In some embodiments the number average molecular weight of (R30)n is from 400 to 950, suitably from 500 to 840, for example from 570 to 630.

In some embodiments the number average molecular weight of (R30)n is from 700 to 1300, suitably from 800 to 1200, for example from 900 to 1100.

R4 is hydrogen or an optionally substituted hydrocarbyl group.

In some embodiments n is 0 and the compound of formula (I) may be formed from an alcohol of formula R4OH. In such embodiments R4 is suitably an optionally substituted alkyl, alkenyl, aryl, or aralkyl group, preferably having from 1 to 60, preferably from 10 to 40, carbon atoms. Preferably R4 is an optionally substituted alkyl group. In some embodiments R4 is a hydroxy In some preferred embodiments R4 is an unsubstituted or aryl-substituted alkyl group. The alkyl group may be straight chained or branched. In some embodiments R4 is an optionally substituted alkyl group having from 4 to 40, preferably from 6 to 30, more preferably from 10 to 20 carbon atoms. Preferably, R4 is a dodecyl group or a furan-2-ylmethyl group.

In some embodiments n is 0 and R4 is an optionally substituted C6 to C36 alkyl group, preferably an optionally substituted Ca to C30 alkyl group, more preferably an optionally substituted Cie to C20 alkyl group.

In some embodiments n is not 0 and the compound of formula (I) may suitably be formed from an alcohol of formula HO(R30)nR4.

In some embodiments R4 is a residue of the formula -C(0)-X'-C(0)-R2' wherein X' is defined according to X herein and R2 is defined according to R2 herein.

The compound of formula (I) may therefore be represented by the formula (I): O(R30)n R2I wherein each of R2, X, R3, n, X' and R2 is as defined herein.

In the formula (I'), R2 and R2' may be the same and/or X and X' may be the same.

When R4 is hydrogen the compound of formula (I) is suitably an ester of an alkylene glycol or a polyalkylene glycol.

When R4 is not hydrogen, the compound of formula (I) may be formed by reaction of the optionally substituted dicarboxylic acid with an alkylene glycol or polyalkylene glycol which is subsequently reacted to form an ether, or a compound of formula HO(R30),R4 may be reacted with the optionally substituted dicarboxylic acid.

R5 may be hydrogen, an alkyl group, a hydroxyalkyl group, a dialkylaminoalkyl group, an alkenyl group, an aryl group, or an aralkyl group. R5 may be hydrogen or an alkyl group or a hydroxyalkyl group. Suitably R5 is selected from hydrogen and an alkyl or hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms. R5 may be selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, hydroxyoctyl, 3-dimethylaminopropyl, benzyl and isomers thereof.

Suitably R5 is hydrogen, an alkyl group or a hydroxyalkyl group. Preferably R5 is hydrogen or a hydroxyalkyl group, such as hydroxyethyl.

R6 may be an alkyl group, a hydroxyalkyl group, a dialkylaminoalkyl group, an alkenyl group, an aryl group, an aralkyl group, or the residue of an amino acid, such as an alkyl group, a hydroxyalkyl group, a dialkylaminoalkyl group, an alkenyl group, an aryl group, or an aralkyl group. Suitable residues of amino acids include residues of aspartic acid, glutamic acid, glutamine, asparagine, serine, threonine, tyrosine, histidine, tryptophan, lysine, and arginine, preferably lysine and arginine. R6 may be an alkyl group, a hydroxyalkyl group, or the residue of an amino acid, such as an alkyl group or a hydroxyalkyl group. Suitably R6 is selected from an alkyl or hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms. R6 may be selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, hydroxyoctyl, 3-dimethylaminopropyl, benzyl, the residue of lysine, the residue of arginine, and isomers thereof, such as from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, hydroxyoctyl, 3-dimethylaminopropyl, benzyl, and isomers thereof Preferably R6 is a hydroxyalkyl group, such as hydroxyethyl, an aralkyl group, such as benzyl, or the residue of an amino acid, such as the residue of lysine or arginine. Preferably R6 is a hydroxyalkyl group, such as hydroxyethyl, or an aralkyl group, such as benzyl.

Preferably R5 is hydrogen and R6 is a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxyethyl, an aralkyl group such as benzyl, or the residue of an amino acid such as lysine or arginine (preferably a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxyethyl, or an aralkyl group such as benzyl); or both R5 and R6 are a hydroxyalkyl group having from 1 to 6 carbon atoms, for example from 1 to 4 carbon atoms, such as hydroxyethyl. Suitably both R5 and R6 are the same hydroxyalkyl group.

In some embodiments R1 is am', ci(R3o)nR4 or NR5R6 and R2 is at or OH.

In some embodiments R1 and R2 are each aw, or R1 is at and R2 is am+ or OH, or R1 is 0(R30)nR4 and R2 is am+ or OH, or R1 is NR5R6 and R2 is am. or OH, or R1 and R2 are each 0(R30)nR4, or R1 and R2 are each NR5R6, or R1 is 0(R30)nR4 and R2 is NR5R6.

In some embodiments R1 and R2 are each O-M'.

In some embodiments R1 is 0-M+ and R2 is am. or OH.

In some embodiments R1 is 0(R30)nR4 and R2 is at or OH.

In some embodiments R1 is NR5R6 and R2 is am. or OH.

In some embodiments R1 and R2 are each 0(R30)nR4.

In some embodiments R1 and R2 are each NR5R6.

In some embodiments R1 is 0(R30)nR4 and R2 is NR5R6.

In a preferred embodiment of the compound of formula (I): X is a 1,2-phenylene group or CH2CHR or CHRCH2 wherein R is R is octenyl, decenyl, or dodecenyl; R1 is a [R'R8R9R10N.], 0(R30)nR4, or NR5R6; and R2 is 0-Nat or OH; wherein n is at least 1, R3 is ethylene, R4 is hydrogen and (R30)n has a number average molecular weight of from 190 to 210; or n is 0 and R4 is dodecyl or furan-2-ylmethyl; R5 is hydrogen or hydroxyethyl; R6 is hydroxyethyl, benzyl, or the residue of lysine or arginine (such as hydroxyethyl or benzyl); and each of R', R6, R9 and R1° are hydrogen; or R' is hydroxypropyl, hydroxybutyl, the residue of lysine, or the residue of arginine, and each of R8, R9 and R1° are hydrogen; or R1° is hydrogen, R7 and R8 are hydroxyethyl, and R9 is hydroxyethyl or sulfoethyl, In a preferred embodiment of the compound of formula (I): X is a 1,2-phenylene group or CH2CHR or CHRCH2 wherein R is R is octenyl, decenyl, or dodecenyl; R1 is a [R'R8R9R10N.], 0(R30)nR4, or NR5R6; and R2 is 0-Na. or OH; wherein n is at least 1, R3 is ethylene, R4 is hydrogen and (R30)n has a number average molecular weight of from 190 to 210; or n is 0 and R4 is dodecyl or furan-2-ylmethyl; 25 30 35 R5 is hydrogen or hydroxyethyl; R6 is hydroxyethyl or benzyl; and each of R', R8, R9 and R1° are hydrogen; or R1° is hydrogen, R7 and R8 are hydroxyethyl, and R9 is hydroxyethyl or sulfoethyl, According to a preferred embodiment of the first aspect of the present invention there may provided the use of a compound for preventing or reducing corrosion and/orstaining of a metallic surface in a cleaning process, wherein the compound comprises: (i) an amine salt of a hydrocarbyl substituted polycarboxylic acid or an anhydride thereof; (ii) a salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a polyalkylene glycol, or a salt of the reaction product; (iii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a primary or secondary amine substituted with at least one hydroxyalkyl group, or a salt of the reaction product; or (iv) a combination of (i), (ii), and/or (iii).

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) an amine salt of a hydrocarbyl substituted polycarboxylic acid or an anhydride thereof; (ii) a salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a polyalkylene glycol, or a salt of the reaction product; (iii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a primary or secondary amine substituted with at least one hydroxyalkyl group, or a salt of the reaction product; or (iv) a combination of (i), (ii), and/or (iii); and contacting the at least a portion of the metallic surface with a cleaning agent.

According to a preferred embodiment of the first aspect of the present invention there may provided the use of a compound for preventing or reducing corrosion and/orstaining of a metallic surface in a cleaning process, wherein the compound comprises: (i) an ammonium salt, an isopropanolamine salt, an aminomethyl propanol salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium or amine salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, or arginine; or (iii) a combination of (i) and (ii).

According to a preferred embodiment of the first aspect of the present invention there may provided the use of a compound for preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, wherein the compound comprises: (i) an ammonium salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, or diethanolamine; or (iii) a combination of (i) and (ii).

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) an ammonium salt, an isopropanolamine salt, an aminomethyl propanol salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium or amine salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, or arginine; or (iii) a combination of (i) and (ii); and contacting the at least a portion of the metallic surface with a cleaning agent.

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) an ammonium salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, or diethanolamine; or (iii) a combination of (i) and (ii); and contacting the at least a portion of the metallic surface with a cleaning agent.

The use and method of the first and second aspects of the present invention suitably prevent or reduce corrosion of the metallic surface. The use and method of the first and second aspects of the present invention suitably prevent or reduce tarnishing of the metallic surface. The use and method of the first and second aspects of the present invention suitably prevent or reduce staining of the metallic surface. Preferably, the use and method of the first and second aspects of the present invention prevent or reduce corrosion and staining of the metallic surface.

In the use and method of the first and second aspects of the present invention, the metallic surface suitably comprises aluminium, iron, steel (preferably stainless steel), copper, zinc, silver, tin, and/or gold. The metallic surface may comprise an alloy comprising at least one of aluminium, iron, copper, zinc, silver, tin, and/or gold, such as bronze or steel. Suitably, the metallic surface comprises aluminium, stainless steel, copper, silver, and/or gold. Preferably, the metallic surface comprises aluminium or silver.

In one embodiment, the metallic surface is an aluminium surface. By "aluminium surface" we mean a surface comprising aluminium. The aluminium surface may comprise pure aluminium or an alloy of aluminium with another metal. The aluminium surface suitably comprises aluminium in an amount of at least 60 wt%, such as at least 80 wt%, preferably at least 90 wt%, for example at least 99 wt% based on the total weight of the aluminium surface.

In one embodiment, the metallic surface is a silver surface. By "silver surface" we mean a surface comprising silver. The silver surface may comprise pure silver or an alloy of silver with another metal, such as copper or nickel. The silver surface suitably comprises silver in an amount of at least 60 wt%, such as at least 80 wt%, preferably at least 90 wt%, for example at least 99 wt% based on the total weight of the silver surface. The silver surface may be formed of any suitable grade of silver, such as 999 grade silver, 925 grade silver, or 900 grade silver. Suitably, the 925 grade silver and the 900 grade silver are an alloy of silver and copper. The 925 grade silver suitably comprises 92.5 wt% silver and 7.5 wt% copper. The 900 grade silver suitably comprises 90.0 wt% silver and 10.0 wt% copper.

In one embodiment, the metallic surface is a silver surface and the use and method of the first and second aspects of the present invention suitably prevent or reduce corrosion, preferably tarnishing, of the silver surface.

According to a preferred embodiment of the first aspect of the present invention there may be provided the use of a compound for preventing or reducing corrosion (preferably tarnishing) of a silver surface in a cleaning process, wherein the compound comprises: (i) an ammonium salt, an isopropanolamine salt, an aminomethyl propanol salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium or amine salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, or arginine; or (iii) a combination of (i) and (ii).

According to a preferred embodiment of the first aspect of the present invention there may be provided the use of a compound for preventing or reducing corrosion (preferably tarnishing) of a silver surface in a cleaning process, wherein the compound comprises: (i) an ammonium salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, or diethanolamine; or (iii) a combination of (i) and (ii).

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion (preferably tarnishing) of a silver surface in a cleaning process, the method comprising: contacting at least a portion of the silver surface with a compound, wherein the compound comprises: (i) an ammonium salt, an isopropanolamine salt, an aminomethyl propanol salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium or amine salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, or arginine; or (iii) a combination of (i) and (ii); and contacting the at least a portion of the silver surface with a cleaning agent.

According to a preferred embodiment of the second aspect of the present invention there may be provided a method of preventing or reducing corrosion (preferably tarnishing) of a silver surface in a cleaning process, the method comprising: contacting at least a portion of the silver surface with a compound, wherein the compound comprises: (i) an ammonium salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, or diethanolamine; or (iii) a combination of (i) and (ii); and contacting the at least a portion of the silver surface with a cleaning agent.

Suitably, the metallic surface is a surface of equipment selected from a washing machine, a sink, a pipe, an automatic dishwasher, a kitchen utensil, tableware, and/or cookware. In embodiments where the equipment comprises multiple components, the metallic surface may be a surface of one or more of the components. The metallic surface may be a surface of equipment cleaned in the cleaning process (such as a sink, a pipe, a kitchen utensil, tableware, or cookware) and/or a surface of equipment which is used to carry out the cleaning process (such as a washing machine, a sink, a pipe, or an automatic dishwasher). Preferably, the metallic surface is a surface of equipment selected from an automatic dishwasher, a kitchen utensil, tableware, and cookware.

In some preferred embodiments, the metallic surface is a surface of an automatic dishwasher. In such embodiments, the cleaning process may be a process of washing the automatic dishwasher (preferably one or more interior surfaces of the automatic dishwasher). The automatic dishwasher may be washed (e.g. via a wash cycle of the automatic dishwasher) in the absence of kitchen utensils, tableware, or cookware.

In embodiments where the metallic surface is a silver surface, the silver surface is suitably the surface of tableware, for example silverware.

The equipment may be entirely metallic (for example, metallic kitchen utensils, tableware or cookware). Alternatively, the equipment may not be entirely metallic. For example, the equipment comprising the metallic surface may also comprise a non-metallic surface, such as a polymer surface. In some embodiments, the metallic surface is a metallic coating on a substrate wherein the substrate may be non-metallic.

The cleaning process may be a domestic cleaning process.

Alternatively, the cleaning process may be a non-domestic cleaning process, such as an industrial cleaning process or an institutional cleaning process.

The cleaning process is suitably a dishwashing process or a laundry washing process. The cleaning process may be a manual dishwashing process. Preferably, the cleaning process is an automatic dishwashing process.

In embodiments where the metallic surface is a silver surface, the cleaning process is preferably an automatic dishwashing process.

Suitably, the cleaning process is an automatic dishwashing process and the metallic surface is located within an automatic dishwasher. In such an embodiment, the compound may be in the form of an automatic dishwashing composition according to the third aspect of the present invention. The metallic surface is suitably a surface of equipment selected from an automatic dishwasher, a kitchen utensil, tableware, and cookware. The compound as defined herein may be contacted with at least a portion of the metallic surface before, during or after a wash cycle of the automatic dishwasher. The compound as defined herein may be contacted with at least a portion of the metallic surface before the wash cycle as part of a pre-treatment step. The compound as defined herein is suitably released into a wash cycle of the automatic dishwasher. The cleaning agent is suitably released into a wash cycle of the automatic dishwasher, for example simultaneously with the compound as defined herein. The compound as defined herein may be contacted with at least a portion of the metallic surface after the wash cycle, for example as part of a rinse aid.

In the use of the first aspect, preferably at least a portion of the metallic surface is contacted with a cleaning agent during the cleaning process. In the method of the second aspect, at least a portion of the metallic surface of the metallic equipment is contacted with a cleaning agent.

The cleaning agent may be any suitable compound or composition which has the effect of cleaning a surface, for example by removing dirt or grease from the surface. The cleaning agent suitably comprises a surfactant, an enzyme, and/or a bleaching agent. Suitable surfactants include cationic surfactants, anionic surfactants, non-ionic surfactants and amphoteric surfactants. Preferably, the cleaning agent comprises a bleaching agent. The cleaning agent may be contacted with at least a portion of the metallic surface in the form of an aqueous solution.

The at least a portion of the metallic surface may be contacted with the cleaning agent at any suitable temperature. In some embodiments, the at least a portion of the metallic surface is contacted with the cleaning agent at ambient temperature, for example at a temperature of from 15 to 25°C. Suitably, the at least a portion of the metallic surface is contacted with the cleaning agent at a temperature of at least 15°C, such as at least 45°C, for example at least 80°C. For example, the at least a portion of the metallic surface may be contacted with the cleaning agent at a temperature of from 15 to 100°C, such as from 15 to 70°C, such as from 30 to 70°C, for example from 45 to 60°C. In some embodiments, the at least a portion of the metallic surface may be contacted with the cleaning agent at a temperature of from 70 to 100°C, such as from 80 to 90°C.

The at least a portion of the metallic surface may be contacted with the compound as defined herein and the cleaning agent simultaneously. For example, the compound may be present in the same composition as the cleaning agent. Alternatively, the at least a portion of the metallic surface may be contacted with the compound as defined herein and the cleaning agent sequentially. Suitably, the at least a portion of the metallic surface is contacted with the compound before the at least a portion of the metallic surface is contacted with the cleaning agent.

The compound as defined herein may be used (in all aspects of the invention) at a suitable treat rate (i.e. so as to provide an effect in preventing or reducing corrosion and/or staining), such as at a treat rate of from 1 to 10,000 ppm, for example from 2 to 5,000 ppm, such as from 5 to 1,500 ppm, or preferably from 50 to 1000 ppm (based on active compound). The compound may be used at a treat rate of from 1 to 250 ppm, such as from 1 to 100 ppm, for example from 1 to 60 ppm, or preferably from 1 to 50 ppm.

According to a third aspect of the present invention, there is provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii); and (b) a builder.

According to a preferred embodiment of the third aspect of the present invention, there may be provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (b) a builder.

According to a preferred embodiment of the third aspect of the present invention, there may be provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; and (b) a builder.

According to a preferred embodiment of the third aspect of the present invention, there is provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising (iii) a combination of (i) and (ii): (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; and (b) a builder.

According to a preferred embodiment of the third aspect of the present invention, there may be provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising: (i) an amine salt of an optionally a hydrocarbyl substituted polycarboxylic acid or an anhydride 25 thereof; (ii) a salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a polyalkylene glycol, or a salt of the reaction product; (iii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a primary or secondary amine substituted with at least one hydroxyalkyl group, or a salt of the reaction product; or (iv) a combination of (i), (ii), and/or (iii); and (b) a builder.

According to a preferred embodiment of the third aspect of the present invention, there may be provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising: (i) an ammonium salt, an isopropanolamine salt, an aminomethyl propanol salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium or amine salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, or arginine; or (iii) a combination of (i) and (ii); and (b) a builder.

According to a preferred embodiment of the third aspect of the present invention, there may be provided an automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising: (i) an ammonium salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; (ii) a sodium salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, or diethanolamine; or (iii) a combination of (i) and (ii); and (b) a builder.

Suitable builders will be known to those skilled in the art. Suitably, the builder is present in an amount of from 15 to 70 wt% based on the total weight of the automatic dishwashing composition, In some embodiments, the builder comprises a phosphorus-containing builder. The phosphorus-containing builder is suitably selected from phosphonates (such as HEDP (1-hydroxyethylidene-1,1-disphosphonic acid)), mono-phosphates, di-phosphates, tripolyphosphates and oligomeric-polyphosphates. The phosphorus-containing builder is suitably present in an amount of from 15 to 60 wt% based on the total weight of the automatic dishwashing composition.

Preferably, the builder comprises a phosphorus-free builder. The phosphorus-free builder suitably comprises a polycarboxylate, such as an aminocarboxylate. Suitable phosphorus-free builders include methylglycine diacetic acid (MGDA), N,N-dicarboxymethyl glutamic acid (GLDA), aspartic acid-N-monoacetic acid (ASMA), aspartic acid-N,N-diacetic acid (ASDA), aspartic acid-N-monopropionic acid (ASMP), iminodisuccinic acid (IDA), N-(2-sulfomethyfiaspartic acid (SMAS), N-(2-sulfoethyl)aspartic acid (SEAS), N-(2-sulfomethyl)glutamic acid (SMGL), N-(2-sulfoethyl)glutamic acid (SEGL), N-methyliminodiacetic acid (MIDA), a-alanine-N,N-diacetic acid (a-ALDA), b-alanine-N,N-diacetic acid (b-ALDA), serine-N,N-diacetic acid (SEDA), isoserine-N,N-diacetic acid (ISDA), phenylalanine-N,N-diacetic acid (PHDA), anthranilic acid-N,N-diacetic acid (ANDA), sulfanilic acid-N,N-diacetic acid (SLDA), taurine-N,N-diacetic acid (TUDA) and sulfomethyl-N,N-diacetic acid (SMDA), iminodisuccinic acid (IDS), (hydroxy)iminodisuccinic acid (HIDS), ethylenediamine-N,N'-disuccinic acid (EDDS), malonic acid, (ethylenedioxy)diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid, fumaric acid, citric acid, homopolymers of acrylic acid, polyepoxysuccinic acids (PESAs), and salts, esters and derivatives thereof. Suitably, the salts are water-soluble. Preferably, the salts are alkali metal salts (such as sodium salts), alkanolamine salts, or ammonium salts. Preferably, the phosphorus-free builder comprises one or more of methylglycine diacetic acid (MGDA), N,N-dicarboxymethyl glutamic acid (GLDA), citric acid, or salts, esters or derivatives thereof. Preferably, the phosphorus-free builder comprises trisodium citrate.

The automatic dishwashing composition may further comprise: (c) an additive selected from anti-tarnishing agents, pH control agents, bleaching agents, bleach activating agents, surfactants, silicates, fillers, pearlescent agents, anti-bacterial agents, softening agents, thickening agents, stabilising agents, defoaming agents, bleach scavenging agents, solvents or hydrotropes, flow control agents, enzymes, enzyme stabilising agents, solid suspending agents, anti-redeposition agents, dispersing agents, anti-scaling agents, colourants, perfumes, dishwasher salts, and rinse aids.

The additive may comprise an anti-tarnishing agent other than the compound as defined herein.

The additive may comprise a bleaching agent. The bleaching agent suitably comprises a peroxy bleaching agent or a halogen bleaching agent.

The peroxy bleaching agent may be organic or inorganic. The organic peroxy bleaching agent may comprise a monoperoxy acid such as an alkyl peroxy acid or an aryl peroxy acid or a diperoxy acid such as an alkyl diperoxy acid or an aryl diperoxy acid. Suitable organic peroxy bleaching agents include: (i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, such as peroxy-alpha-naphthoic acid and magnesium monoperphthalate; (ii) aliphatic and substituted aliphatic monoperoxy acids, such as peroxylauric acid, peroxystearic acid, epsilon-phthalimido peroxyhexanoic acid, o-carboxybenzamido peroxyhexanoic acid, N-nonenylamidoperadipic acid and N-nonenylamidopersuccinic acid; (iii) 1,12-diperoxydodecanedioic acid; (iv) 1, 9-diperoxyazelaic acid; (v) diperoxybrassylic acid, diperoxysebacic acid and diperoxyisophthalic acid; (vi) 2-decyldiperoxybutane-1,4-dioic acid; (vii) N,N-terephthaloyl-di(6-aminopercaproic acid); (viii) diacylperoxides such as dibenzoylperoxide; and (ix) phthalimidoperoxyhexanoic acid.

The inorganic bleaching agent may be selected from monopersulfate, perborate monohydrate, perborate tetrahydrate, and percarbonate.

The peroxy bleaching agent may comprise a precursor to peroxygen bleach, such as p15 benzoyloxybenzene sulfonate, N,N,N',N'-tetraacetylethylene diamine, sodium nonanoyloxybenzene sulfonate or choline sulfophenyl carbonate.

The halogen bleaching agent may comprise a hypohalite or a precursor thereto (which yield hypohalite anions in alkaline conditions). Suitable halogen bleaching agents include lithium, sodium or calcium hypochlorite and hypobromite, halogenated (e.g. with chlorine or bromine) trisodium phosphate, trichloroisocyanuric acid, dichloroisocyanuric acid, and salts thereof, especially the sodium salts. Commercial sources of chlorinated isocyanuric acids include, for example, ACL-59 (trade mark) supplied by Mansanto Company, and Clearon CDB-56 (trade mark) supplied by Olin Corporation.

The additive may comprise a bleach activating agent. The bleach activating agent may comprise a manganese compound. a cobalt (Ill) compound, or tetraacetyleneethylenediamine (TAED). Suitable manganese compounds include mononuclear compounds, such as manganese acetate or manganese oxalate, or dinuclear compounds, such as those disclosed in EP1741774.

The additive may comprise a surfactant. Suitable surfactants include anionic surfactants, cationic surfactants, non-ionic surfactants and amphoteric surfactants.

The surfactant may comprise an anionic surfactant. The anionic surfactant may be selected from sulfates (such as alkyl ether sulfates), sulfonates (such as alkylbenzene sulfonates), or carboxylates (such as alkyl ether carboxylates, succinates or sarcosinates). Suitable anionic surfactants include magnesium laureth sulfate, ammonium laureth sulfate, ammonium lauryl sulfate, MEA lauryl sulfate, TEA lauryl sulfate, sodium lauryl sulfate, sodium coco sulfate, sodium C14-16 olefin sulfonates, sodium dodecylbenzene sulfonate, laureth-11 carboxylic acid, laureth-5 carboxylic acid, sodium laureth-5 carboxylate, capryleth-6 carboxylic acid, disodium laureth-3 sulfosuccinate, diethylhexyl sodium succinate, and sodium lauroyl sarcosinate. Preferably, the anionic surfactant comprises capryleth-6 carboxylic acid.

The surfactant may comprise a cationic surfactant. The cationic surfactant may be selected from betaines (such as alkyl betaines and alkylamidopropyl betaines), amphoacetates, diamphoacetates, and amine oxides (such as alkylamine oxides and alkylamidopropyl amine oxides). Suitable cationic surfactants include lauryl betaine, cocamidopropyl betaine, sodium lauroamphoacetate, sodium cocoamphoacetate, disodium cocoamphodiacetate, lauramine oxide, C12-18 alkyldimethylamine oxide, myristamine oxide, and cocamidopropyl amine oxide.

Preferably, the cationic surfactant comprises cocamidopropyl amine oxide.

The surfactant may comprise a non-ionic surfactant. The non-ionic surfactant may be selected from fatty alcohol alkoxylates (such as fatty alcohol ethoxylates, fatty alcohol propoxylates, and fatty alcohol mixed ethoxylates/propoxylates) and fatty acid alkanolamides. Suitable non-ionic surfactants include deceth-5, C12-is pareth-7, C12-15 pareth-9, C12-15 pareth-11, trideceth-6, C911 pareth-5, C9_11 pareth-6, C9-11 pareth-8, deceth-7, PPG-4-undeceth-7; PPG-5-undeceth-7, coconut methyl ester ethoxylate (10 EO), cocamide DEA, cocamide MIPA, and cocamide MEA. Preferably, the non-ionic surfactant comprises trideceth-6.

The automatic dishwashing composition may advantageously comprise components derived from renewable sources. Suitably the surfactants used in automatic dishwashing composition have a percentage renewable carbon index (%RCI) of at least 90%, suitably at least 98%, based on the total amount of surfactants in the automatic dishwashing composition. The renewable carbon index (RCI) for a component is calculated according to ISO 16128-1:2016 -Annex C, wherein the number of carbon atoms derived from renewable sources is divided by the total number of carbon atoms in a component. The total RCI of the automatic dishwashing composition is a weighted average of the RCI of each carbon-containing surfactant in the automatic dishwashing composition. The %RCI is obtained by multiplying the RCI by 100. The term "surfactant" is well understood by a person skilled in the art and such a skilled person would readily understand which components of the automatic dishwashing composition are surfactants.

In some embodiments the automatic dishwashing composition comprises less than 5 wt% of sodium lauryl sulfate and sodium laureth sulfate, preferably less than 2.5 wt%, more preferably less than 1 wt% of sodium lauryl sulfate and sodium laureth sulfate. The automatic dishwashing composition may comprise less than 5 wt% of sulfate surfactants, preferably less than 2.5 wt%, more preferably less than 1 wt% of sulfate surfactants. In some embodiments the composition may be substantially free from sodium lauryl sulfate and sodium laureth sulfate. In some embodiments the composition may be substantially free from sulfate surfactants. By "substantially free" from a component we mean that such a component is not deliberately added to the composition.

The additive may comprise a silicate, such as a sodium silicate or a potassium silicate.

Preferably, the silicate comprises Si02:Na20 comprising from 1.0 to 3.3, preferably from 2.0 to 3.2 molar equivalents of SiO2 per molar equivalent of Na2O.

The additive may comprise a filler. The filler may comprise an organic filler or an inorganic filler.

Suitably, the filler does not comprise calcium or magnesium ions. Suitable fillers include sucrose esters, urea, sodium sulfate, sodium chloride, and potassium chloride. Preferably, the filler comprises sodium sulfate. The filler may be present in an amount of up to 60 wt%, such as from 10 to 30 wt%, based on the total weight of the automatic dishwashing composition.

The additive may comprise a softening agent. Preferably, the softening agent comprises hydroxyethyl laurdimonium chloride.

The additive may comprise a thickening agent. The thickening agent may be selected from clays, cross-linked acrylic acid polymers, and salts of polyacrylic acid. Examples of suitable thickening agents are described in US4,431,559; US4,511,487; US4,740,327; US4,752,409; US4,859,358; US4,836,948; US4,867,896; and GB2164350. In embodiments where the additive comprises a thickening agent, the automatic dishwashing composition is suitably in the form of a liquid, a gel, or a paste.

The thickening agent may comprise a clay. The clay may comprise a smectite clay selected from montmorillonite (bentonite), hectorite, saponite; silica, silica gel, and aluminosilicate. Commercially available synthetic smectite clays include Laponite (trade mark) supplied by Laporte Industries. Commercially available bentonite clays include Korthix H and VWH available from Combustion Engineering, Inc.; Polargel T available from American Colloid Co.; and Gelwhite clays (particularly Gelwhite GP and H) available from English China Clay.

The thickening agent may comprise a cross-linked acrylic acid polymer. Suitable cross-linked acrylic acid polymers include those sold under the tradename "Carbopol", such as Carbopol 940 and 617. Suitably, the cross-linked acrylic acid polymer has a number average molecular weight of about 4,000,000 and the automatic dishwashing composition is in the form of a clear gel.

The thickening agent may comprise a salt of polyacrylic acid. The salts of polyacrylic acid may be cross-linked. The salt of polyacrylic acid suitably has a number average molecular weight of at least 300,000, such as from 300,000 to 6,000,000.

The additive may comprise a stabilising agent. Suitable stabilising agents include long-chain soaps and C12 to Cis sulfates, Laponite (trade mark), metal oxides, salts of metal oxides, compounds comprising trivalent metal ions, and water-soluble structuring chelants. In embodiments where the additive comprises a stabilising agent, the automatic dishwashing composition is suitably in the form of a liquid, a gel, or a paste.

Suitable long-chain calcium and sodium soaps and C12 to C18 sulfates are described in US3,956,158 and US4,271,030 and other suitable metal salts of long-chain soaps are described in US4,752,409. Suitable Laponite (trade mark) and metal oxides and their salts are described in US4,933,101. Such stabilising agents may be present in an amount of from 0.01 to 5 wt%, preferably from 0.01 to 2 wt% based on the total weight of the automatic dishwashing composition, preferably wherein the automatic dishwashing composition is in the form of a liquid.

Compounds containing trivalent metal ions are suitably present in an amount of from 0.01 to 4 wt% based on the total weight of the automatic dishwashing composition. Laponite and/or water-soluble structuring chelants are suitably present in an amount of from 1 to 60 wt% based on the total weight of the automatic dishwashing composition. In such embodiments the automatic dishwashing composition is suitably in the form of a gel.

The additive may comprise a defoaming agent. The defoaming agent may comprise a silicone.

The additive may comprise a bleach scavenging agent. Suitable bleach scavenging agents include sodium bisulphite, sodium perborate, reducing sugars, and short-chain alcohols.

The additive may comprise a solvents or hydrotrope. Suitably solvents and hydrotropes include ethanol, isopropanol, alkylbenzene sulfonates such as sodium xylene sulfonates, potassium cumenesulfonate, sodium cumenesulfonate, and sodium toluenesulfonate. Preferably, the solvent or hydrotrope comprises an alkylbenzene sulfonate.

The additive may comprise an enzyme. Suitable enzymes include proteases (e.g., Alcalase (trade mark), Savinase (trade mark) and Esperase (trade mark) from Novo Industries A/S), amylases (e.g. , Termamyl (trade mark) from Novo Industries A/S), lipases (e.g., Lipolase (trade mark) from Novo Industries NS) , oxidases, and mixtures thereof.

The automatic dishwashing composition is suitably in the form of a tablet, a powder, granules, flakes, a liquid, a gel, a paste, or a combination thereof. Suitably, the automatic dishwashing composition is provided in an automatic dishwashing product. The automatic dishwashing product is suitably in the form of a tablet. The tablet may comprise a water-soluble coating. The tablet suitably comprises a compartment comprising the automatic dishwashing composition, preferably in the form of a liquid. The tablet may comprise one or more other compartments comprise one or more other additives. The one or more other additives may be in any suitable form, such as a powder or a liquid. Suitably, the tablet comprises two or more compartments and the compartments are divided by a water-soluble coating.

Any feature of any aspect of any invention or embodiment described herein may be combined with any aspect of any other invention or embodiment described herein mutatis mutandis. For example, suitable features of the metallic surface and the compound in the third aspect are as defined for the first and second aspects.

According to a preferred embodiment of the fourth aspect of the present invention, there may be provided the use of a compound for preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, wherein the compound comprises (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof.

According to a preferred embodiment of the fourth aspect of the present invention, there may be provided the use of a compound for preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, wherein the compound comprises (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the fourth aspect of the present invention, there is provided the use of a compound for preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, wherein the compound comprises (iii) a combination of (i) and (ii): (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the fifth aspect of the present invention, there may be provided the use of a compound for preventing or reducing staining of a metallic surface, wherein the compound comprises (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof.

According to a preferred embodiment of the fifth aspect of the present invention, there may be provided the use of a compound for preventing or reducing staining of a metallic surface, wherein the compound comprises (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the fifth aspect of the present invention, there is provided the use of a compound for preventing or reducing staining of a metallic surface, wherein the compound comprises (iii) a combination of (i) and (ii): (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the sixth aspect of the present invention, there is provided a method of preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof According to a preferred embodiment of the sixth aspect of the present invention, there is provided a method of preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the sixth aspect of the present invention, there is provided a method of preventing or reducing corrosion of a metallic surface comprising a metal selected from stainless steel, silver, and gold, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (iii) a combination of (i) and (ii): (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the seventh aspect of the present invention, there is provided a method of preventing or reducing staining of a metallic surface, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof.

According to a preferred embodiment of the seventh aspect of the present invention, there is provided a method of preventing or reducing staining of a metallic surface, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

According to a preferred embodiment of the seventh aspect of the present invention, there is provided a method of preventing or reducing staining of a metallic surface, the method comprising contacting at least a portion of the metallic surface with a compound, wherein the compound comprises (iii) a combination of (i) and (ii): (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; and (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product.

In embodiments of the fourth and sixth aspects, the metallic surface is suitably a silver surface.

The silver surface is suitably as defined in relation to the first and second aspects.

In some embodiments of the fifth and seventh aspects, the metallic surface suitably comprises aluminium, iron, steel (preferably stainless steel), copper, zinc, silver, tin, and/or gold. The metallic surface may comprise an alloy comprising at least one of aluminium, iron, copper, zinc, silver, tin, and/or gold, such as bronze. Suitably, the metallic surface comprises aluminium, stainless steel, copper, silver, and/or gold. Preferably, the metallic surface comprises aluminium or silver. In one embodiment, the metallic surface is an aluminium surface. In one embodiment, the metallic surface is a silver surface.

Any feature of any aspect of any invention or embodiment described herein may be combined with any aspect of any other invention or embodiment described herein mutatis mutandis. For example, suitable features of the metallic surface and the compound in the fourth, fifth, sixth and seventh aspects are as defined for the first, second and third aspects.

For example, in the fourth, fifth, sixth and seventh aspects, the compound may comprise (i) an alkali metal or amine salt of an optionally substituted polycarboxylic acid or an anhydride thereof, suitably a sodium salt or potassium salt, preferably a sodium salt. Suitable amines used to form the salt of an optionally substituted polycarboxylic acid or an anhydride thereof include ammonia, primary, secondary and tertiary amines and quaternary ammonium compounds as discussed above in relation to the first, second and third aspects.

For example, in the fourth, fifth, sixth and seventh aspects, the compound may comprise (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a polyhydric alcohol and/or a primary or secondary amine (such as a secondary amine), wherein the optionally substituted polycarboxylic acid or anhydride thereof, the polyhydric alcohol and the primary or secondary amine are suitably as discussed above in relation to the first, second and third aspects. Alternatively, the compound may comprise a salt of (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a polyhydric alcohol and/or a primary or secondary amine (such as a secondary amine), wherein the salt is suitably as discussed above in relation to the first, second and third aspects.

For example, in some embodiments, in the fourth, fifth, sixth and seventh aspects, a suitable polyhydric alcohol for use to form the reaction product may have from 2 to 4 hydroxy groups and/or from 1 to 40 carbon atoms, such as from 6 to 30 carbon atoms, for example from 6 to 20 carbon atoms. Suitably the polyhydric alcohol comprises an alkylene glycol or a polyalkylene glycol (preferably a polyalkylene glycol). Suitable alkylene and polyalkylene glycols are as discussed above in relation to the first, second and third aspects.

In some embodiments, in the fourth, fifth, sixth and seventh aspects, the salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and a polyhydric alcohol is suitably an alkali metal salt, preferably a sodium or potassium salt, more preferably a sodium salt.

For example, in some embodiments, in the fourth, fifth, sixth and seventh aspects, a suitable amine for use to form the reaction product may comprise a primary or secondary amine as discussed above in relation to the first, second and third aspects. The amine may be an alkylamine, a hydroxyalkylamine, a dialkylamine, a hydroxyalkyl alkyl amine, a dihydroxyalkylamine, or the residue of an amino acid (such as an alkylamine, a hydroxyalkylamine, a dialkylamine, a hydroxyalkyl alkyl amine, or a dihydroxyalkylamine), as discussed above in relation to the first, second and third aspects.

In some embodiments, in the fourth, fifth, sixth and seventh aspects, the salt of the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an amine is suitably an alkali metal salt, preferably a sodium or potassium salt, more preferably a sodium salt.

In some embodiments, in the fourth, fifth, sixth and seventh aspects, the compound comprises (i) an ammonium salt, an isopropanolamine salt, an aminomethyl propanol salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; and/or (ii) a sodium or amine salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, or arginine.

In some embodiments, in the fourth, fifth, sixth and seventh aspects, the compound comprises (i) an ammonium salt, a triethanolamine salt, or an N,N-bis(hydroxyethyl)taurine salt of octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, or an anhydride thereof; and/or (ii) a sodium salt of the reaction product of reactants comprising octenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, phthalic acid, or an anhydride thereof and dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, or diethanolamine.

The compounds (i) and (ii) of all aspects of the present invention are suitably biodegradable in the conditions used and/or have low aquatic toxicity.

Brief Description of the Drawings

For a better understanding of the invention, and to show how exemplary embodiments of the same may be carried into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which: Figure 1 shows a photograph of the top of (a) a silver spoon exposed to a control and (b) a silver spoon exposed to water.

Figure 2 shows a photograph of the bottom of the silver spoons of Figure 1.

Figure 3 shows a photograph of the top of (a) a silver spoon exposed to a control and (b) a silver spoon exposed to a solution of Sample 4 (sodium diethanolamine dodecenylsuccinamide) in water.

The invention will now be further described with reference to the following non-limiting examples.

Examples

Samples 1 to 9 were characterised by IR using a Thermo Scientific Nicolet iS5 FT-IT spectrometer with an iD7 diamond ATR crystal accessory. Persons skilled in the art would recognise that the reactions of Example 1 may form reaction products that comprise mixtures of reaction products, as well as unreacted reactants and/or by-products.

Example 1 -Synthesis Sample 1 -Preparation of sodium PEG200 2-octen-1-ylsuccinate 10.0 g (1.0 eq) 2-octen-1-ylsuccinic anhydride (mixture of isomers) and 9.5 g (1.0 eq) PEG200* were heated to 95°C for 4 hours. The reaction mixture was cooled to room temperature and 10 wt% NaOH solution in deionised (DI) water (19.0 9, 1.0 eq) was added and stirred for 30 minutes. The reaction mixture was diluted with deionised water to a concentration of 40 wt% product in DI water (as the sodium salt). ;IR acid ester -2923, 2871, 1731, 1442, 1123, 1065 cm 1 IR sodium salt -3382, 1728, 1649, 1568, 1398, 1098 cm 1 The product is believed to comprise a mixture of reaction products, primarily the mono ester compound with some bis ester compound also present. ;*PEG200 is a polyethylene glycol having an average molecular weight of 200.

Sample 2 -Preparation of sodium furfuryl alcohol dodecenyl succinic anhydride 8.50 g (1.0 eq) dodecenyl succinic anhydride was combined with 3.13 g (1.0 eq) furfuryl alcohol and refluxed at 95°C for 2 hours. The reaction mixture was cooled to room temperature and 10 wt% NaOH solution in DI water (12.8 g, 1.0 eq) was added and stirred for 30 minutes. DI water was added to give a 25 wt% solution product (as the sodium salt).

IR acid ester -2955, 2916, 2855, 1742, 1703, 1410, 1161 cm 1 IR sodium salt -2955, 2920, 1623, 1551, 1386, 1291, 1165 cm 1 The product is believed to comprise a mixture of reaction products, primarily the mono ester compound.

Sample 3 -Preparation of sodium dodecanol phthalate 5.00 g (1.0 eq) phthalic anhydride was combined with 6.29 g (1.0 eq) dodecanol and refluxed at 120°C for 2 hours. The reaction mixture was cooled to room temperature and 10 wt% NaOH solution in DI water (13.5 9, 1.0 eq) was added and stirred for 30 minutes. DI water was added to give a 25 wt% solution product.

IR acid ester -2912, 2849, 1738, 1687, 1571, 1449, 1414, 1275, 1248, 1106 cm 1 IR sodium salt -2921, 2843, 1634, 1555, 1391, 1278, 1131, 1075 cm 1 The product is believed to comprise a mixture of reaction products, primarily the mono ester compound.

Sample 4 -Preparation of sodium diethanolamine dodecenylsuccinamide 10.0 g (1.0 eq) dodecenylsuccinic anhydride (DDSA, mixture of isomers) and 4.0 g (1.0 eq) diethanolamine were heated to 95°C for 2 hours. The reaction mixture was cooled to room temperature and 10 wt% NaOH solution in DI water (15.2 g, 1.0 eq) was added and stirred for 30 minutes. The aqueous layer was separated and diluted with deionised water to give a 25 wt% solution product (as the sodium salt).

IR acid amide -2956, 2929, 2871, 1732, 1621, 1563, 1454, 1379, 1161, 1066 cm-1 IR sodium salt -3323, 2956, 2929, 2871, 1722, 1614, 1564, 1397, 1049 cm-1 The product is believed to comprise a mixture of reaction products, primarily the diethanolamide compound with some ester compounds (due to reaction of the hydroxy group on the diethanolamine) also present.

Sample 5 -Preparation of dodecenyl succinic acid mono triethanolamine salt 10.0g (1.0 eq) of dodecenylsuccinic anhydride (mixture of isomers) was refluxed in water (30 ml) for 4 hours. The reaction mixture was cooled to room temperature, then triethanolamine (TEA) (5.6 g, 1.0 eq) was added and stirred for 1 hour. The reaction mixture was diluted with deionised water to a concentration of 25 wt% product in DI water.

IR -2957, 2929, 2872, 1704, 1424, 1231 cm 1 Sample 6 -Preparation of sodium benzylamine 2-octen-1-ylsuccinamide 10.0 g (1.0 eq) 2-octen-1-ylsuccinic anhydride (mixture of isomers) and 5.1 g (1.0 eq) benzylamine were heated to 75°C for 2 hours. The reaction mixture was cooled to room temperature and 10 wt% NaOH solution in deionised (DI) water (19.0 g, 1.0 eq) was added and stirred for 30 minutes. A final concentration of 47 wt% product in DI water (as the sodium salt) was obtained.

IR acid amide -3285, 2955, 2923, 2854, 1706, 1644, 1545, 1230, 1167 cm-1 IR sodium salt -3294, 2955, 2924, 2854, 1634, 1556, 1400 cm-1 The product is believed to comprise a mixture of reaction products, primarily the mono amide compound.

Sample 7 -Preparation of sodium monoethanolamine 2-octen-1-ylsuccinamide 10.0 g (1.0 eq) 2-octen-1-ylsuccinic anhydride (mixture of isomers) and 2.9 g (1.0 eq) monoethanolamine were heated to 75°C for 2 hours. The reaction mixture was cooled to room temperature and 10 wt% NaOH solution in deionised (DI) water (19.0 g, 1.0 eq) was added and stirred for 30 minutes. A final concentration of 44 wt% product in DI water (as the sodium salt) was obtained.

IR acid amide -3303, 2955, 2923, 2855, 1706, 1643, 1548, 1400, 1165 cm-1 IR sodium salt -3279, 2956, 2924, 2854, 1637, 1556, 1400 cm-1 The product is believed to comprise a mixture of reaction products, primarily the monoethanolamide compound with some ester compounds (due to reaction of the hydroxy group on the monoethanolamine) also present.

Sample 8 -Preparation of 2-octen-1-ylsuccinate N,N-bis(2-hydroxyethyl) taurine salt 10.0g (1 eq) of 2-octen-1-ylsuccinic anhydride (mixture of isomers) was refluxed in water (20 ml) for 2 hours. The reaction mixture was cooled to room temperature, then N,N-bis(2-hydroxyethyl) taurine (BES) (10.2 g, 1 eq) was added and stirred for 1 hour. A final concentration of 50 wt% product in DI water was obtained.

IR -3384, 2957, 2925, 1709, 1643, 1162 cm 1 Sample 9 -Preparation of 2-octen-1-ylsuccinate ammonium salt 10.0g (1 eq) of 2-octen-1-ylsuccinic anhydride (mixture of isomers) and ammonium solution (35 wt% solution in water) (2.3g) were heated to 70°C for 2 hours. The reaction mixture was cooled to room temperature yielding the product at a final concentration of 88 wt% product in DI water.

IR -2956, 2924, 2855, 1707, 1659, 1409, 1185 cm 1 Sample 10 -Preparation of dodecenyl succinic acid 1-aminopropan-2-ol salt 10.0g (1.0 eq) of dodecenylsuccinic anhydride (mixture of isomers) was refluxed in water (30 ml) for 4 hours. The reaction mixture was cooled to room temperature, then 1-aminopropan-2-ol (MIPA) (2.8 g, 1.0 eq) was added and stirred for 1 hour. The reaction mixture was diluted with deionised water to a concentration of 25 wt% product in DI water.

IR -2922, 2853, 1698, 1622, 1568, 1411, 1221 cm 1 Sample 11 -Preparation of dodecenyl succinic acid 2-amino-2-methyl-1-propanol salt 10.0g (1.0 eq) of dodecenylsuccinic anhydride (mixture of isomers) and water (0.7 ml, 1.0 eq) were heated to 80°C for 2 hours. The reaction mixture was cooled to room temperature, then 2-amino-2-methyl-1-propanol (AMP) (3.3 g, 1.0 eq) was added and stirred for 1 hour to yield the final product.

IR -2921, 2852, 1698, 1632, 1545, 1398, 1178, 1051 cm 1 Sample 12 -Preparation of lysine dodecenylsuccinamide 10.0g (1.0 eq) of dodecenylsuccinic anhydride (mixture of isomers), lysine (11.0 g, 2.0 eq) and water (60 ml) were heated to 80°C for 72 hours. The reaction mixture was cooled to room temperature and diluted with deionised water to a concentration of 20 wt% product in DI water.

IR -3158, 3095, 2977, 1697, 1604, 1511, 1348, 1093, 1039 cm 1 The product is believed to comprise a mixture of reaction products, primarily the half-amide half-amine salt.

Sample 13 -Preparation of arginine dodecenylsuccinamide 10.0g (1.0 eq) of dodecenylsuccinic anhydride (mixture of isomers), arginine (13.1 g, 2.0 eq) and water (50 ml) were heated to 80°C for 72 hours. The reaction mixture was cooled to room temperature and diluted with deionised water to a concentration of 25 wt% product in DI water.

IR -3352, 3195, 2927, 1698, 1631, 1555, 1215, 1095 cm-1 The product is believed to comprise a mixture of reaction products, primarily the half-amide half-amine salt.

Example 2 -Testing

Cleaning protocol A silver item (i.e. a silver (925 grade) spoon) was polished with 240 grit silicon carbide paper to remove the visible tarnish from the surface before being further polished using 150 mesh silicon carbide grains on cotton wool. All polishing grit was removed with clean cotton wool before the silver item was immersed in the test solution as described in the test methods set out below.

Test method -no sample A silver (925 grade) spoon cleaned according to the cleaning protocol above was placed in a stirred solution of 700m1 of DI water before heating the solution from 25°C to 70°C over a period of 20 minutes. After this time, the silver spoon showed considerable yellowing/browning, as shown in Figure 1(b) and Figure 2(b). Figures 1(a) and 2(a) show a corresponding silver spoon that was not contacted with the solution.

Test method -with sample A silver (925 grade) spoon cleaned according to the cleaning protocol above was placed in a stirred solution of 700m1 of DI water alone or containing 1Oppm (on an active basis) of one of samples 1 to 13 before heating from 25°C to 70°C over a period of 20 minutes. Figure 3(b) shows that a spoon contacted with sample 4 did not show tarnishing. Figure 3(a) shows a corresponding silver spoon that was not contacted with the solution.

The silver spoons tested were visually assessed and anti-tarnish scores ranging from 0-5 according to level of tarnishing were recorded.

Sample Tarnish Score None 5 1 0 4 0 0 6 0 7 2 8 1 9 1 0 11 0 12 0 13 1 The tarnish score was assigned as follows: 0 -no tarnishing 1 -a small number of brown spots on the spoon surface 2 -a large number of brown spots on the spoon surface 3 -discolouration and shine loss 4 -strong discolouration/shine loss -very strong discolouration The results show that compounds according to the present invention were effective in preventing or reducing tarnishing of a silver spoon.

The present invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims 1. The use of a compound for preventing or reducing corrosion and/or staining of a metallic surface in a cleaning process, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii).
2. A method of preventing or reducing corrosion and/orstaining of a metallic surface in a cleaning process, the method comprising: contacting at least a portion of the metallic surface with a compound, wherein the compound comprises: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii); and contacting the at least a portion of the metallic surface with a cleaning agent.
3. A use or method according to claim 1 or 2, wherein the optionally substituted polycarboxylic acid or the anhydride thereof comprises an optionally substituted succinic acid or an optionally substituted succinic anhydride.
4. A use or method according to any preceding claim, wherein the optionally substituted polycarboxylic acid or the anhydride thereof is substituted with an alkyl, alkenyl, alkaryl or aralkyl 25 group.
5. A use or method according to claim 4, wherein the alkyl or alkenyl group has from 2 to 36 carbon atoms, such as from 4 to 22 carbon atoms, for example from 6 to 18 carbon atoms.
6. A use or method according to claim 4, wherein the alkyl or alkenyl group is a polyisobutenyl group.
7. A use or method according to any preceding claim, wherein the salt of the optionally substituted polycarboxylic acid or the anhydride thereof or the salt of the reaction product comprises an alkali metal salt and/or an amine salt.
8. A use or method according to claim 7, wherein the amine salt comprises an ammonium salt, a primary amine salt, or a tertiary amine salt.
9. A use or method according to claim 8, wherein the amine used to form the salt is selected from ammonia, isopropanolamine, aminomethyl propanol, triethanolamine, and N,N-bis(2-hydroxyethyl)taurine.
10. A use or method according to any preceding claim, wherein the compound comprises a mono amine salt of a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof
11. A use or method according to any preceding claim, wherein the alcohol comprises a polyalkylene glycol.
12. A use or method according to claim 11, wherein the polyalkylene glycol comprises polyethylene glycol having a number average molecular weight of from 60 to 370 or from 400 to 950.
13. A use or method according to any preceding claim, wherein the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a polyethylene glycol, wherein the acid/anhydride and the polyethylene glycol are reacted in a molar ratio of from 1.1:1 to 1:1.1.
14. A use or method according to any preceding claim, wherein the amine comprises a primary or secondary amine.
15. A use or method according to any preceding claim, wherein the amine is substituted with at least one hydroxyalkyl group.
16. A use or method according to any preceding claim, wherein the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and a dihydroxyalkylamine, wherein the acid/anhydride and the dihydroxyalkylamine are reacted in a molar ratio of from 1.5:1 to 1:1.5.
17. A use or method according to any preceding claim, wherein the compound comprises a salt of the reaction product of reactants comprising a hydrocarbyl substituted dicarboxylic acid or an anhydride thereof and an amino acid, wherein the acid/anhydride and the amino acid are reacted in a molar ratio of from 1:1.5 to 1:2.5.
18. A use or method according to claim 17, wherein the amino acid is selected from aspartic acid, glutamic acid, glutamine, asparagine, serine, threonine, tyrosine, histidine, tryptophan, lysine, and arginine, preferably lysine and arginine.
19. A use or method according to any preceding claim, wherein the compound comprises a compound of formula (I): (I) wherein X is a linking group; R1 is 0-M+, 0(R30)nR4, or NR5R6; and R2 is OH, ant, 0(R30)nR4, or NR5R6; wherein each kith is independently a cation; each R3 is independently an optionally substituted alkylene group; each R4 is independently hydrogen or an optionally substituted hydrocarbyl group; each R5 is independently hydrogen or an optionally substituted hydrocarbyl group; each R6 is independently an optionally substituted hydrocarbyl group; each n is independently 0 or a positive integer, provided that n is not 0 when R4 is hydrogen.
20. A use or method according to claim 19, wherein X is CH2CHR or CHRCH2 wherein R is an optionally substituted hydrocarbyl group.
21. A use or method according to any one of claims 1 to 9, wherein the alcohol and/or the amine is selected from dodecanol, furfuryl alcohol, benzylamine, PEG 200, monoethanolamine, diethanolamine, lysine, and arginine.
22. A use or method according to any preceding claim, wherein the metallic surface comprises aluminium, stainless steel, copper, silver, tin, and/or gold.
23. A use or method according to claim 22, wherein the metallic surface comprises aluminium. 5
24. A use or method according to claim 22, wherein the metallic surface is a silver surface and the use or method prevent or reduce corrosion, preferably tarnishing, of the silver surface.
25. A use or method according to any preceding claim, wherein the metallic surface is a surface of equipment selected from a washing machine, a sink, a pipe, an automatic dishwasher, a kitchen utensil, tableware, and cookware.
26. A use or method according to claim 25, wherein the metallic surface is a surface of equipment selected from an automatic dishwasher, a kitchen utensil, tableware, and cookware. 15
27. A use or method according to any one of claims 1 to 26, wherein the cleaning process is an automatic dishwashing process.
28. An automatic dishwashing composition for inhibiting corrosion and/or staining of a metallic surface, the composition comprising: (a) a compound comprising: (i) a salt of an optionally substituted polycarboxylic acid or an anhydride thereof; (ii) the reaction product of reactants comprising an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol and/or an amine, or a salt of the reaction product; or (iii) a combination of (i) and (ii); and (b) a builder.
29. A composition according to claim 28, wherein the composition further comprises: (c) an additive selected from anti-tarnishing agents, pH control agents, bleaching agents, bleach activating agents, surfactants, silicates, fillers, pearlescent agents, anti-bacterial agents, softening agents, thickening agents, stabilising agents, defoaming agents, bleach scavenging agents, solvents or hydrotropes, flow control agents, enzymes, enzyme stabilising agents, solid suspending agents, anti-redeposition agents, dispersing agents, anti-scaling agents, colourants, perfumes, dishwasher salts, and rinse aids.