Ashless ionic liquid

1 . An ionic liquid comprising:

an anionic portion that is selected from one or more of formula Ia or formula Ic:

wherein:

x is an integer of 3;

each R 1 is independently selected from a linear, branched or cyclic C 1 -C 20 aliphatic hydrocarbyl group that is saturated or unsaturated, a C 6 -C 10 aryl group, and a 5-10 membered heteroaromatic ring system;

R 2 is selected from the group consisting of a linear, branched or cyclic C 1 -C 40 aliphatic hydrocarbyl group that is saturated or unsaturated, a linear or branched C 2 -C 40 polyalkyleneglycol group, a C 6 -C 22 aryl group, a moiety formed by removing two hydroxyl groups from a sugar alcohol, and a moiety formed by removing two hydroxyl groups from a dehydrated sugar alcohol or isosorbide;

R 5 is selected from the group consisting of a linear, branched or cyclic C 1 -C 20 aliphatic hydrocarbyl group that is saturated or unsaturated, a linear or branched C 2 -C 20 polyalkyleneglycol group, a C 6 -C 22 aryl group, a moiety formed by removing x hydroxyl groups from a sugar alcohol, and a moiety formed by removing x hydroxyl groups from a dehydrated sugar alcohol; and

each R 6 independently represents a linear, branched or cyclic C 1 -C 20 aliphatic hydrocarbyl group that is saturated or unsaturated,

wherein for each of R 1 , R 2 , R 5 and R 6 :

each of the C 1 -C 20 aliphatic hydrocarbyl group, C 1 -C 40 aliphatic hydrocarbyl group, C 2 -C 40 polyalkyleneglycol group, and C 2 -C 20 polyalkyleneglycol group are not interrupted or are interrupted by one or more groups selected from an aromatic or non- aromatic ring system having from 5 to 14 atoms, an ester group, an amide group, and a carbamate group, and

each of the C 1 -C 20 aliphatic hydrocarbyl group, C 1 -C 40 aliphatic hydrocarbyl group, C 2 -C 40 polyalkyleneglycol group, C 2 -C 20 polyalkyleneglycol group, and C 6 -C 22 aryl group are unsubstituted or substituted by one or more groups selected from the group consisting of hydroxyl, primary amino, secondary amino and tertiary amino, where the secondary and tertiary amino groups are substituted by one or two C 1-10 hydrocarbyl groups, respectively; and

each J independently represents O or NRN, where RN represents H or a C 1 -C 18 alkyl or alkenyl group

a cationic portion having formula A:

(

X

)

n

a

+

,

A

where:

X represents a cationic species; and

a and n are selected to approximately balance the charge of the ionic liquid, wherein the ionic liquid is ashless.

2 . The ionic liquid according to claim 1 , wherein one or more of the following applies:

(a) each R 1 is independently selected from a phenyl group, a furan group or, more particularly, a linear or branched C 4 -C 18 aliphatic hydrocarbyl group that is saturated or unsaturated;

(b) R 2 is a moiety formed by removing both hydroxyl groups from isosorbide, or more particularly, a linear or branched C 2 -C 20 aliphatic hydrocarbyl group, or a linear or branched C 2 -C 20 polyalkyleneglycol,

where the linear or branched C 2 -C 20 aliphatic hydrocarbyl group and the linear or branched C 2 -C 20 polyalkyleneglycol are saturated or unsaturated,

where the linear or branched C 2 -C 20 aliphatic hydrocarbyl group and the linear or branched C 2 -C 20 polyalkyleneglycol are not interrupted or is interrupted by one or more groups selected from an aromatic or non-aromatic ring system having 5 or 6 atoms, an amide group, and a carbamate group;

(c) R 5 is selected from the group consisting of a linear or branched C 3 -C 14 aliphatic hydrocarbyl group that is saturated or unsaturated, a C 6 -C 10 aryl group, a moiety formed by removing x hydroxyl groups from a sugar alcohol, and a moiety formed by removing x hydroxyl groups from a dehydrated sugar alcohol; and

(d) each R 6 is independently selected from a phenyl group, a furan group or, more particularly, a linear or branched C 4 -C 18 aliphatic hydrocarbyl group that is saturated or unsaturated.

3 . The ionic liquid according to claim 1 , wherein one or more of the following applies:

(a) each R 1 independently represents a moiety formed by removing both carboxylic acid groups from a compound selected from the list consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,18-octadecanedioic acid, terephthalic acid, isophthalic acid, phthalic acid, and 2,5-furandicarboxylic acid;

(b) each J represents O and R 2 is a group formed by removing two hydroxyl groups from a compound selected from the following:

neopentyl glycol, 1,5-pentanediol, 1,9-nonanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 2,5-hexanediol, 2,7-octanediol, a saturated straight chain C 28 1,14-diol, an unsaturated straight chain C 28 1,14-diol,

where each Z independently represents a C 1 to C 12 aliphatic hydrocarbyl group;

(c) one of the following applies:

R 2 represents a C 4-16 alkylene group and each J represents NH; or

R 2 represents propylene, one J represents NH and the other J represents NR N where R N represents oleyl;

(d) R 5 is selected from the group consisting of a phenyl ring, and a branched C 3 -C 10 aliphatic group; and

(e) each R 6 independently represents a moiety formed by removing both carboxylic acid groups from a compound selected from the list consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,18-octadecanedioic acid, terephthalic acid, isophthalic acid, phthalic acid, and 2,5-furandicarboxylic acid.

4 . The ionic liquid according to claim 1 , wherein:

R 5 is a moiety formed by removing three hydroxyl groups from a compound selected from the group consisting of trimethylolpropane, glycerol, pyrogallol, hydroxyquinol, phloroglucinol, and 3-methylpentane-1,3,5-triol.

5 . The ionic liquid according to claim 1 , wherein R 2 represents a branched alkylene group

6 . The ionic liquid according to claim 1 , wherein R 5 represents a branched group

7 . The ionic liquid according to claim 1 , wherein the anionic portion is of formula Ia.

8 . The ionic liquid according to claim 1 , wherein the anionic portion is of formula Ic and has the structure:

9 . The ionic liquid according to claim 1 , wherein the cationic portion is selected from one or more of the group consisting of a quaternary phosphonium cation, a quaternary sulphonium cation, a quaternary ammonium cation comprising at least one amide group, a quaternary ammonium cation comprising at least one ester group, a substituted quaternary imidazolium cation comprising at least one ester group, a substituted quaternary imidazolium cation comprising at least one alkyleneglycol group, a substituted quaternary imidazolium cation comprising at least one amide group, azaannulenium, azathiazolium, benzimidazolium, benzofuranium, benzothiophenium, benzotriazolium, borolium, cinnolinium, diazabicyclodecenium, diazabicyclononenium, 1,4- diazabicyclo [2.2.2]octanium, diazabicyclo-undecenium, dibenzofuranium, dibenzothiophenium, dithiazolium, dithiazolium, furanium, guanidinium, imidazolium, indazolium, indolinium, indolium, morpholinium, oxaborolium, oxaphospholium, oxazinium, oxazolium, iso-oxazolium, oxazolinium, pentazolium oxothiazolium, phospholium, phosphonium, phthalazinium, piperazinium, piperidinium, pyranium, pyrazinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, pyrrolium, quinazolinium, quinolinium, isoquinolinium, quinoxalinium, quinuclidinium, selenazolium, sulfonium, tetrazolium, thiadiazolium, iso-thiadiazolium, thiazinium, thiazolium, iso-thiazolium, thiophenium, thiuronium, triazadecenium, triazinium, triazolium, iso-triazolium, combinations thereof, and cationic molecules comprising more than one of the foregoing.

10 . The ionic liquid according to claim 1 , wherein the cationic portion has the formula [YX 3 X 4 X 5 X 6 ] + ,

wherein:

Y represents N, P or S; and

(a) each of X 3 to X 6 are independently selected from C 1 to C 30 straight chain or branched alkyl and alkenyl groups; C 3 to C 6 cycloalkyl groups; C 1 to C 30 arylalkyl groups; C 1 to C 30 alkylaryl groups; aryl groups; or any two of X 3 to X 6 combine to form an alkylene chain —(CH 2 ) q — wherein q is from 3 to 6; wherein any one or more of said straight or branched chain alkyl and alkenyl groups, cycloalkyl groups, arylalkyl groups, alkylaryl groups; aryl groups or alkylene chains are optionally substituted by one to three groups selected from: C 1 to C 4 alkoxy, C 2 to C 8 alkoxyalkoxy, C 3 to C 6 cycloalkyl, —OH, —NH 2 , —SH, —CO 2 (C 1 to C 6 )alkyl, and —OC(O)(C 1 to C 6 )alkyl; or

(b) at least one of X 3 to X 6 have the formula —X 7 O(C═O)X 8 or —X 7 (C═O)—O—X 8 , wherein X 7 is a C 1 to C 10 straight chain or branched alkyl or alkenyl group, or a C 3 to C 6 cycloalkyl or cycloalkenyl group; and X 8 is a C 1 to C 30 straight chain or branched alkyl or alkenyl group; a C 3 to C 6 cycloalkyl group; a C 1 to C 30 arylalkyl group; a C 1 to C 30 alkylaryl group; an aryl group; or any two respective X 8 groups combine to form an alkylene chain —(CH 2 ) q — wherein q is from 3 to 6; wherein X 7 and/or X 8 are optionally substituted by one to three groups selected from: C 1 to C 4 alkoxy, C 2 to C 8 alkoxyalkoxy, C 3 to C 6 cycloalkyl, —OH, —NH 2 , —SH, —CO 2 (C 1 to C 6 )alkyl, and —OC(O)(C 1 to C 6 )alkyl;

and wherein the other of X 3 to X 6 that are not as defined above are independently selected from C 1 to C 30 straight chain or branched alkyl and alkenyl groups such as C 1 to C 10 alkyl or alkenyl groups; C 3 to C 6 cycloalkyl groups; C 1 to C 30 arylalkyl groups; C 1 to C 30 alkylaryl groups; aryl groups; or any two of X 3 , X 4 , X 5 and X 6 combine to form an alkylene chain —(CH 2 ) q — wherein q is from 3 to 6; wherein any one or more of said straight or branched chain alkyl and alkenyl groups, cycloalkyl groups, arylalkyl groups, alkylaryl groups; aryl groups or alkylene chains is optionally substituted by one to three groups selected from: C 1 to C 4 alkoxy, C 2 to C 8 alkoxyalkoxy, C 3 to C 6 cycloalkyl, —OH, —NH 2 , —SH, —CO 2 (C 1 to C 6 )alkyl, and —OC(O)(C 1 to C 6 )alkyl.

11 . The ionic liquid according to claim 10 , wherein option (a) applies.

12 . A composition comprising:

a base fluid, and

an liquid as defined in claim 1 .

13 . A method of reducing the friction of a base fluid or of a polyol ester, said method comprising the steps:

(i) providing a base oil or a polyol ester;

(ii) mixing the base oil or polyol ester with an amount of an ionic liquid as defined in claim 1 .

14 . A method of preparing an ionic liquid as defined in any one of claim 1 , said method comprising the steps:

(i) providing an intermediate product comprising:

an ester group or an amide group; and

a carboxylic acid group (ii) converting the intermediate product to an ionic liquid by either:

(a) directly reacting the intermediate product with a cationic base;

(b) deprotonating the intermediate esters with a base to form an ester alkaline/metal salts, subsequently conducting a metathesis reaction between the ester salt with a salt compound that comprises a cationic portion having formula A; or (c) reacting the intermediate product with an alkylamine or arylamine.

15 . A salt comprising:

an anionic portion as defined in claim 1 , and

a cationic portion comprising one or more alkali metal cations.

16 . A method of preparing a salt as defined in claim 15 , said method comprising the steps:

(i) reacting an alcohol with a dicarboxylic acid to produce an intermediate product comprising an ester group and a carboxylic acid group;

ii) reacting the intermediate product with a basic salt of an alkali metal to form a salt as defined in claim 15 .