Grease Thickening Agent

This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/351,582 entitled “GREASE THICKENING AGENT,” filed Jun. 13, 2022, the disclosure of which is incorporated herein in its entirety by reference. This application further claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/423,815 entitled “GREASE THICKENING AGENT,” filed Nov. 9, 2022, the disclosure of which is incorporated herein in its entirety by reference. This application further claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/463,576 entitled “GREASE THICKENING AGENT,” filed May 3, 2023, the disclosure of which is incorporated herein in its entirety by reference.

Grease compositions provide lubrication for a variety of articles. While it is important for the grease composition to include adequate lubricating and base oils, a grease thickening agent is needed to provide mechanical properties to the grease composition.

The present disclosure provides a polyamide grease thickening agent having the structure according to Formula I.

In Formula I, at each occurrence PCA is independently a reacted polycarboxylate, at each occurrence MCA is independently a reacted monocaboxylate, at each occurrence DA is independently a reacted diamine, and y is 0 or a non-zero integer. Additionally, in Formula I, a weight-average molecular weight of the polyamide grease thickener is in a range of from about 450 g/mol to about 3500 g/mol. Additionally, in Formula I, the structure includes at least 4 amide bonds and at least two internal aromatic moieties are di-substituted in a para position.

Surprisingly and unexpectedly, according to various aspects of the present disclosure, the grease thickening compositions are able to perform at least substantially equivalently to a corresponding grease thickening agent that includes lithium, polyurea, or both. Thus it is possible to formulate grease compositions that are substantially free of lithium, polyurea, or both.

Reference will now be made in detail to certain embodiments of the disclosed subject matter. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” or “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

In the methods described herein, the acts can be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. The term “substantially free of” as used herein can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that about 0 wt % to about 5 wt % of the composition is the material, or about 0 wt % to about 1 wt %, or about 5 wt % or less, or less than or equal to about 4.5 wt %, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt % or less, or about 0 wt %.

The term “organic group” as used herein refers to any carbon-containing functional group. Examples can include an oxygen-containing group such as an alkoxy group, aryloxy group, aralkyloxy group, oxo(carbonyl) group; a carboxyl group including a carboxylic acid, carboxylate, and a carboxylate ester; a sulfur-containing group such as an alkyl and aryl sulfide group; and other heteroatom-containing groups. Non-limiting examples of organic groups include OR, OOR, OC(O)N(R), CN, CF, OCF, R, C(O), methylenedioxy, ethylenedioxy, N(R), SR, SOR, SOR, SON(R), SOR, C(O)R, C(O)C(O)R, C(O)CHC(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R), OC(O)N(R), C(S)N(R), (CH)N(R)C(O)R, (CH)N(R)N(R), N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)CON(R), N(R)SOR, N(R)SON(R), N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(O)N(R), N(R)C(S)N(R), N(COR)COR, N(OR)R, C(═NH)N(R), C(O)N(OR)R, C(═NOR)R, and substituted or unsubstituted (C-C)hydrocarbyl, wherein R can be hydrogen (in examples that include other carbon atoms) or a carbon-based moiety, and wherein the carbon-based moiety can be substituted or unsubstituted.

The term “substituted” as used herein in conjunction with a molecule or an organic group as defined herein refers to the state in which one or more hydrogen atoms contained therein are replaced by one or more non-hydrogen atoms. The term “functional group” or “substituent” as used herein refers to a group that can be or is substituted onto a molecule or onto an organic group. Examples of substituents or functional groups include, but are not limited to, a halogen (e.g., F, Cl, Br, and I); an oxygen atom in groups such as hydroxy groups, alkoxy groups, aryloxy groups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groups including carboxylic acids, carboxylates, and carboxylate esters; a sulfur atom in groups such as thiol groups, alkyl and aryl sulfide groups, sulfoxide groups, sulfone groups, sulfonyl groups, and sulfonamide groups; a nitrogen atom in groups such as amines, hydroxyamines, nitriles, nitro groups, N-oxides, hydrazides, azides, and enamines; and other heteroatoms in various other groups. Non-limiting examples of substituents that can be bonded to a substituted carbon (or other) atom include F, Cl, Br, I, OR, OC(O)N(R), CN, NO, NO, ONO, azido, CF, OCF, R, O (oxo), S (thiono), C(O), S(O), methylenedioxy, ethylenedioxy, N(R), SR, SOR, SOR, SON(R), SOR, C(O)R, C(O)C(O)R, C(O)CHC(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R), OC(O)N(R), C(S)N(R), (CH)N(R)C(O)R, (CH)N(R)N(R), N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)CON(R), N(R)SOR, N(R)SON(R), N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(O)N(R), N(R)C(S)N(R), N(COR)COR, N(OR)R, C(═NH)N(R), C(O)N(OR)R, and C(═NOR)R, wherein R can be hydrogen or a carbon-based moiety; for example, R can be hydrogen, (C-C)hydrocarbyl, alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl; or wherein two R groups bonded to a nitrogen atom or to adjacent nitrogen atoms can together with the nitrogen atom or atoms form a heterocyclyl.

The term “alkyl” as used herein refers to straight chain and branched alkyl groups and cycloalkyl groups having from 1 to 40 carbon atoms, 1 to about 20 carbon atoms, 1 to 12 carbons or, in some embodiments, from 1 to 8 carbon atoms. Examples of straight chain alkyl groups include those with from 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Examples of branched alkyl groups include, but are not limited to, isopropyl, iso-butyl, sec-butyl, t-butyl, neopentyl, isopentyl, and 2,2-dimethylpropyl groups. As used herein, the term “alkyl” encompasses n-alkyl, isoalkyl, and anteisoalkyl groups as well as other branched chain forms of alkyl. Representative substituted alkyl groups can be substituted one or more times with any of the groups listed herein, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups.

The term “alkenyl” as used herein refers to straight and branched chain and cyclic alkyl groups as defined herein, except that at least one double bond exists between two carbon atoms. Thus, alkenyl groups have from 2 to 40 carbon atoms, or 2 to about 20 carbon atoms, or 2 to 12 carbon atoms or, in some embodiments, from 2 to 8 carbon atoms. Examples include, but are not limited to vinyl, —CH═CH(CH), —CH═C(CH), —C(CH)=CH, —C(CH)═CH(CH), —C(CHCH)=CH, cyclohexenyl, cyclopentenyl, cyclohexadienyl, butadienyl, pentadienyl, and hexadienyl among others.

The term “alkynyl” as used herein refers to straight and branched chain alkyl groups, except that at least one triple bond exists between two carbon atoms. Thus, alkynyl groups have from 2 to 40 carbon atoms, 2 to about 20 carbon atoms, or from 2 to 12 carbons or, in some embodiments, from 2 to 8 carbon atoms. Examples include, but are not limited to —CH, —C(CH), —C(CHCH), —CHCH, —CHC(CH), and —CHC(CHCH) among others.

The term “acyl” as used herein refers to a group containing a carbonyl moiety wherein the group is bonded via the carbonyl carbon atom. The carbonyl carbon atom is bonded to a hydrogen forming a “formyl” group or is bonded to another carbon atom, which can be part of an alkyl, aryl, aralkyl cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclylalkyl, heteroaryl, heteroarylalkyl group or the like. An acyl group can include 0 to about 12, 0 to about 20, or 0 to about 40 additional carbon atoms bonded to the carbonyl group. An acyl group can include double or triple bonds within the meaning herein. An acryloyl group is an example of an acyl group. An acyl group can also include heteroatoms within the meaning herein. A nicotinoyl group (pyridyl-3-carbonyl) is an example of an acyl group within the meaning herein. Other examples include acetyl, benzoyl, phenylacetyl, pyridylacetyl, cinnamoyl, and acryloyl groups and the like. When the group containing the carbon atom that is bonded to the carbonyl carbon atom contains a halogen, the group is termed a “haloacyl” group. An example is a trifluoroacetyl group.

The term “cycloalkyl” as used herein refers to cyclic alkyl groups such as, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. In some embodiments, the cycloalkyl group can have 3 to about 8-12 ring members, whereas in other embodiments the number of ring carbon atoms range from 3 to 4, 5, 6, or 7. Cycloalkyl groups further include polycyclic cycloalkyl groups such as, but not limited to, norbornyl, adamantyl, bornyl, camphenyl, isocamphenyl, and carenyl groups, and fused rings such as, but not limited to, decalinyl, and the like. Cycloalkyl groups also include rings that are substituted with straight or branched chain alkyl groups as defined herein. Representative substituted cycloalkyl groups can be mono-substituted or substituted more than once, such as, but not limited to, 2,2-, 2,3-, 2,4- 2,5- or 2,6-disubstituted cyclohexyl groups or mono-, di- or tri-substituted norbornyl or cycloheptyl groups, which can be substituted with, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups. The term “cycloalkenyl” alone or in combination denotes a cyclic alkenyl group.

The term “aryl” as used herein refers to cyclic aromatic hydrocarbon groups that do not contain heteroatoms in the ring. Thus aryl groups include, but are not limited to, phenyl, azulenyl, heptalenyl, biphenyl, indacenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl, naphthacenyl, chrysenyl, biphenylenyl, anthracenyl, and naphthyl groups. In some embodiments, aryl groups contain about 6 to about 14 carbons in the ring portions of the groups. Aryl groups can be unsubstituted or substituted, as defined herein. Representative substituted aryl groups can be mono-substituted or substituted more than once, such as, but not limited to, a phenyl group substituted at any one or more of 2-, 3-, 4-, 5-, or 6-positions of the phenyl ring, or a naphthyl group substituted at any one or more of 2- to 8-positions thereof.

The term “aralkyl” as used herein refers to alkyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to an aryl group as defined herein. Representative aralkyl groups include benzyl and phenylethyl groups and fused (cycloalkylaryl)alkyl groups such as 4-ethyl-indanyl. Aralkenyl groups are alkenyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to an aryl group as defined herein.

The term “heterocyclyl” as used herein refers to aromatic and non-aromatic ring compounds containing three or more ring members, of which one or more is a heteroatom such as, but not limited to, N, O, and S.

The term “heteroaryl” as used herein refers to aromatic ring compounds containing 5 or more ring members, of which, one or more is a heteroatom such as, but not limited to, N, O, and S; for instance, heteroaryl rings can have 5 to about 8-12 ring members. A heteroaryl group is a variety of a heterocyclyl group that possesses an aromatic electronic structure.

The term “heterocyclylalkyl” as used herein refers to alkyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group as defined herein is replaced with a bond to a heterocyclyl group as defined herein. Representative heterocyclyl alkyl groups include, but are not limited to, furan-2-yl methyl, furan-3-yl methyl, pyridine-3-yl methyl, tetrahydrofuran-2-yl ethyl, and indol-2-yl propyl.

The term “heteroarylalkyl” as used herein refers to alkyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to a heteroaryl group as defined herein.

The term “alkoxy” as used herein refers to an oxygen atom connected to an alkyl group, including a cycloalkyl group, as are defined herein. Examples of linear alkoxy groups include but are not limited to methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and the like. Examples of branched alkoxy include but are not limited to isopropoxy, sec-butoxy, tert-butoxy, isopentyloxy, isohexyloxy, and the like. Examples of cyclic alkoxy include but are not limited to cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and the like. An alkoxy group can include about 1 to about 12, about 1 to about 20, or about 1 to about 40 carbon atoms bonded to the oxygen atom, and can further include double or triple bonds, and can also include heteroatoms. For example, an allyloxy group or a methoxyethoxy group is also an alkoxy group within the meaning herein, as is a methylenedioxy group in a context where two adjacent atoms of a structure are substituted therewith.

The term “amine” as used herein refers to primary, secondary, and tertiary amines having, e.g., the formula N(group)wherein each group can independently be H or non-H, such as alkyl, aryl, and the like. Amines include but are not limited to R—NH, for example, alkylamines, arylamines, alkylarylamines; RNH wherein each R is independently selected, such as dialkylamines, diarylamines, aralkylamines, heterocyclylamines and the like; and RN wherein each R is independently selected, such as trialkylamines, dialkylarylamines, alkyldiarylamines, triarylamines, and the like. The term “amine” also includes ammonium ions as used herein.

The term “amino group” as used herein refers to a substituent of the form —NH, —NHR, —NR, —NR*, wherein each R is independently selected, and protonated forms of each, except for —NR*, which cannot be protonated. Accordingly, any compound substituted with an amino group can be viewed as an amine. An “amino group” within the meaning herein can be a primary, secondary, tertiary, or quaternary amino group. An “alkylamino” group includes a monoalkylamino, dialkylamino, and trialkylamino group.

The terms “halo,” “halogen,” or “halide” group, as used herein, by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom.

The term “haloalkyl” group, as used herein, includes mono-halo alkyl groups, poly-halo alkyl groups wherein all halo atoms can be the same or different, and per-halo alkyl groups, wherein all hydrogen atoms are replaced by halogen atoms, such as fluoro. Examples of haloalkyl include trifluoromethyl, 1,1-dichloroethyl, 1,2-dichloroethyl, 1,3-dibromo-3,3-difluoropropyl, perfluorobutyl, and the like.

The term “hydrocarbon” or “hydrocarbyl” as used herein refers to a molecule or functional group that includes carbon and hydrogen atoms. The term can also refer to a molecule or functional group that normally includes both carbon and hydrogen atoms but wherein all the hydrogen atoms are substituted with other functional groups. The term “hydrocarbyl” refers to a functional group derived from a straight chain, branched, or cyclic hydrocarbon, and can be alkyl, alkenyl, alkynyl, aryl, cycloalkyl, acyl, or any combination thereof. Hydrocarbyl groups can be shown as (C-C)hydrocarbyl, wherein a and b are integers and mean having any of a to b number of carbon atoms. For example, (C-C)hydrocarbyl means the hydrocarbyl group can be methyl (C), ethyl (C), propyl (C), or butyl (C), and (C-C)hydrocarbyl means in certain embodiments there is no hydrocarbyl group. A hydrocarbylene group is a diradical hydrocarbon, e.g., a hydrocarbon that is bonded at two locations.

The term “weight-average molecular weight” as used herein refers to M, which is equal to ΣMn/ΣMn, where nis the number of molecules of molecular weight M. In various examples, the weight-average molecular weight can be determined using light scattering, small angle neutron scattering, X-ray scattering, and sedimentation velocity.

The polymers described herein can terminate in any suitable way. In some embodiments, the polymers can terminate with an end group that is independently chosen from a suitable polymerization initiator, —H, —OH, a substituted or unsubstituted (C-C)hydrocarbyl (e.g., (C-C)alkyl or (C-C)aryl) interrupted with 0, 1, 2, or 3 groups independently selected from —O—, substituted or unsubstituted —NH—, and —S—, a poly(substituted or unsubstituted (C-C)hydrocarbyloxy), and a poly(substituted or unsubstituted (C-C)hydrocarbylamino).

The origin of any reactant, feedstock, and/or material can be from any available source. Without limitation, examples of such sources can include, natural products, synthetic products, petrochemicals, bio-renewables, recycled materials, or a mixture thereof.

Various aspects of the present disclosure relate to a grease thickening agent. The grease thickening agent is characterized as a polyamide grease thickening agent. It has been found that successful grease thickening agents are those that result in a grease composition having a dropping point greater than 200° C., 220, 240, 260, or 280° C. as well as having a NLGI rating as a group 2 or greater. Structural features of the grease thickener that are found to help achieve these characteristics include that any aliphatic moieties in monomers that are internally disposed in the grease thickener molecule and are n-alkyl (linear), additionally the grease thickener should include at least two para-substituted aromatic moieties, the grease thickener should have a molecular weight in a range of from 450 g/mol to 3500 g/mol, and the grease thickener should include at least four amide bonds. These structural features were found to achieve the desirable physical properties when the grease thickener is incorporated into a grease composition in a concentration in a range of from about 10 wt % to 20 wt %, about 10 wt % to about 15 wt %, less than, equal to, or greater than about 10 wt %, 11, 12, 13, 14, 15, 16, 17, 18, 19, or about 20 wt %.

Various examples of grease thickening agents are described herein. Some of the structures described may not possess each of the aforementioned desirable structural features. However, some grease thickening agents that include at least some of the aforementioned desirable features may provide a grease thickening agent that may perform adequately. Additionally, in various aspects, it can be desirable for a grease composition to include a mixture of grease thickening components. In such a mixture, at least one grease thickening agent can include all of the aforementioned desirable structural features. Additionally, the mixture can include another grease thickener agent that may include fewer than all of the aforementioned structural features or even any of the structural features. However, the mixture itself may still yield desirable properties in the grease composition to which it is incorporated.

The polyamide grease thickening agent can have the structure according to Formula VIII:

In Formula I, at each occurrence ZZ is

at each occurrence PCA is independently a reacted polycarboxylate (e.g., reacted with DA), at each occurrence MCA is independently a reacted monocaboxylate, at each occurrence DA is independently a reacted diamine (e.g., reacted with MCA and one of ZZ or PCA), x is a non-zero integer, y is 0 or a non-zero integer, and z is 0 or a non-zero integer. In some examples, x, y, and z are independently in a range of from 1 to 10, 1 to 3, less than, equal to, or greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The bonds between MCA and DA are amide bonds. The bonds between DA and ZZ or DA and PCA are either amide bonds or imide bonds. As used herein “reacted” means that that the identified starting material has reacted to become part of the grease thickening agent.

The polyamide grease thickening agent can have the structure according to Formula I:

In still further examples, the polyamide grease thickening agent can have the structure according to Formula II:

In Formula II, n is in a range of from 2-4. In still further examples, the polyamide grease thickening agent has the structure according to Formula III:

The reacted polycarboxylate can be a polycarboxylic acid, polycarboxylic ester, polycarboxylic acid chloride, or an anhydride. At each occurrence, PCA can independently include 3 to 50 carbon atoms 6 to 10 carbon items, or 6, 8, or 9 carbon atoms. For example, at each occurrence, PCA can include a reacted polycarboxylate having the structure according to the following Formulas: