Friction reducing additive and method for its preparation

Abstract

A friction reducing additive formed from a mixture obtainable by a self-catalyzed condensation reaction of a fatty acid with an alkanolamine is described, the mixture comprising an amide, one or more carboxylic acid esters and more than 7 wt% oxazoline relative to the total weight of the mixture, wherein the additive is useful in lubricants and fuels.

Description

Technical Field

[0001] This invention relates to friction-reducing additives primarily derived from renewable sources, suitable for lubricating compositions and fuels (including lubricating compositions and fuels from biorenewable sources) and for use in lubricants, such as lubricants for motor vehicles, particularly low and medium saps lubricants (low and medium content of sulfate ash, phosphorus, and sulfur).

[0002] In particular, the present invention relates to additives as defined above, which can advantageously reduce friction in the mechanical moving parts of machines, especially engines, improve their energy efficiency, and thus reduce carbon dioxide emissions.

[0003] More specifically, the present invention relates to friction-reducing additives formed from a mixture of a metal-free organic compound in the form of an amide, one or more carboxylic acid esters, and an oxazoline, said mixture being highly biorenewable because it can be obtained from fatty acids and alkanolamines derived from renewable sources. Background Technology

[0004] Reducing CO2 emissions is a global challenge that involves sectors related to energy production and consumption.

[0005] In the EU, it is estimated that approximately 30% of total CO2 emissions come from the transport sector, with 72% of that being caused by "road transport," distributed as follows:

[0006] 1.2% of motorcycles

[0007] 26.2% of trucks (heavy-duty trucks)

[0008] 11.9% of light trucks

[0009] 60.7% of cars.

[0010] For the reasons mentioned above, the EU has introduced new legal restrictions that, starting in 2021, the CO2 emissions of cars must be equal to or less than 95g CO2 / km.

[0011] Therefore, starting in 2021, manufacturers will have to offer engines on the market that can guarantee a fuel consumption / distance ratio (so-called fuel economy) of 4.1 l / 100 km (Otto cycle engine) and 3.6 l / 100 km (diesel engine).

[0012] In this context, fuels and lubricants from biorenewable sources that can guarantee a lower environmental impact on vehicles will be particularly favored.

[0013] Regarding internal combustion engines, it should be remembered that only 15% of the energy introduced into a car through fuel (according to data from the U.S. Department of Energy) is used to generate the car's motion on the road.

[0014] The remaining percentage of energy (85%) was lost and distributed as follows:

[0015] 20% of the energy is used to start the engine, keep the engine idling, and for auxiliary systems (air conditioning and other electrical devices);

[0016] 35% of the energy is lost due to the heat generated by the engine's thermodynamic cycle;

[0017] 30% of energy is lost due to friction, which is divided into friction of the components that make up the engine and transmission (20%), brake friction (5%), and tire friction (5%).

[0018] Of the energy lost due to friction, it is estimated that about 67% is lost due to friction in the engine and transmission components.

[0019] The friction that causes these energy inefficiencies originates from engine components affected by different load, speed, and temperature operating conditions.

[0020] Since then, research has focused on reducing energy losses caused by friction in internal combustion engines and their transmission systems.

[0021] One of the goals of this study is to reduce the coefficient of friction (COF) between different moving parts without affecting the operation and duration of the moving parts.

[0022] The reduction of COF is usually achieved by acting on the rheological properties of the lubricant (by reducing its viscosity) and using appropriate additives (such as "friction reducers" (FRs), detergents, and viscosity index improvers).

[0023] In fact, by reducing COF, the amount of energy consumed can be reduced, thereby improving fuel economy (distance traveled / fuel used): this reduces fuel consumption per distance traveled, thus reducing CO2 emissions.

[0024] Therefore, fuel economy is a reference parameter for classifying fuels and lubricants based on their energy efficiency and the resulting environmental impact (e.g., reduction of CO2 emissions).

[0025] Additives known as "friction reducers" (FRs) are primarily organic molecules (OFRs), typically amphiphilic, characterized by a hydrocarbon skeleton (>C). 16 And polar heads, such as glycerol monooleate (GMO), or organometallic molecules (MOFR), such as molybdenum dithiocarbamate (MoDTC).

[0026] To date, lubricants have used both metal-organic (MOFR) and organic-free (OFR) friction modifiers (FR).

[0027] The most promising are pure organic additives, as they are more compatible with the most modern exhaust aftertreatment devices, known as "diesel particulate filters" (DPF) and "gasoline particulate filters" (GPF).

[0028] These filters can prevent PM (particulate matter) from entering the atmosphere, thus helping to reduce emissions: however, DPF and GPF not only capture particles, but also all solids emitted in the exhaust gas, including combustion residues from the lubricant portion drawn into the combustion chamber.

[0029] To avoid filter clogging, it is necessary to perform a regeneration cycle at high temperatures (> 600°C) to remove all carbonaceous substances present on the filter.

[0030] Metal elements in lubricants can form non-combustible solid compounds (so-called "ash") at high temperatures.

[0031] Therefore, the metals in the lubricant additives accumulate in the pores of the filter and cannot be removed during normal regeneration cycles.

[0032] Therefore, there is a need for "organic friction modifiers (OFRs)" additives that are free of metal elements, sulfur, and phosphorus, which can produce "low-SAPS" (sulfate ash, phosphorus, and sulfur) lubricants, i.e., lubricants with low sulfate ash, phosphorus, and sulfur content. Lubricants obtained in this way have better compatibility with DPF and GPF filters and significantly delay pore clogging.

[0033] The reduction in the coefficient of friction (COF) after adding a friction reducer (FR) can be evaluated by using one or more suitable friction tests.

[0034] These laboratory tests allow for the estimation of friction and wear associated with lubricants or fuels through the specific measurements reported in the table below (see also the characterization in the examples), and the positive results obtained in all tests are a prerequisite for subjecting lubricants or fuels with additives to more expensive and demanding engine tests.

[0035]

[0036] The HFRR (High Frequency Reciprocating Test Bench) test allows for the evaluation of the lubricity produced by a fuel (generally diesel, but also gasoline), which is assessed as a wear index: the lower the value, the better the fuel performance is considered.

[0037] The SRV test (“Schwingung rei bung und Verschleiss”, or “Vibration, Friction and Wear”), applicable only to lubricants, provides a connection between the sphere and the surface similar to the HFRR test, but the operating conditions developed in-house by the applicant are significantly more demanding.

[0038] At the end of the test, the coefficient of friction (COF, dimensionless) was obtained as an instrument response, and the wear (mm) was measured: again in this case, a low COF and wear value indicate the best performance of the lubricant.

[0039] Another important friction test involves the use of a device called a "miniature traction machine" (MTM) (rig).

[0040] In addition, in this test, COF was measured using a coupling between a loaded steel ball and a steel disc under any slip / roll ratio of up to 100% pure rolling.

[0041] See M. Lattuada and M. Manni, “A new methodology for the experimental evaluation of organic antifriction additives”—The 10th International Symposium on Fuels and Lubricants.

[0042] Because the contact pressure and cutting speed can reach high values ​​in such couplings, very similar to those found in typical gears, rolling bearings and cams of internal combustion engines (ICE), such tests can provide very useful indications about the performance of the lubricant under different lubrication conditions: hydrodynamic (high-thickness friction film between contacting surfaces), mixing (medium-thickness friction film between contacting surfaces), and boundary (thin-thickness friction film between contacting surfaces).

[0043] The “MTM” device is particularly well-suited for constructing Stribek curves, where COF is measured at different sliding velocities between contact surfaces. The area covered by the entire Stribek curve is called the “Stribke coefficient of friction” (SFC), representing a measure of “energy dissipation”.

[0044] Therefore, a low “SFC” value ensures excellent fuel economy, which is typical for lubricants that minimize energy loss due to friction (see features in the examples).

[0045] Typically, when the lubrication state is primarily boundary-type, that is, when the rheological properties (e.g., viscosity) of the lubricant no longer have the same effect as on the hydrodynamic and mixed states, FR additives can reduce COF (see the features described in the examples).

[0046] In the boundary state, the FR additive works according to the mechanism of the adsorption layer, in which the polar part of the molecule is attracted and fixed to the metal surface by strong adsorption forces (hydrogen bonds), while the hydrocarbon part dissolved in the oil is aligned perpendicular to the metal surface (see, for example, Tribology Online, Vol. 5, No. 3 (2010) / 166).

[0047] Furthermore, the polar portions of the FR interact with each other through dipole-dipole interactions, while the nonpolar portions remain aligned and parallel to each other through van der Waals forces. As a result of all this, the ultimate effect is the formation of multi-molecular clusters, which can reduce the coefficient of friction between metal surfaces in a “boundary” lubricated state.

[0048] Different types of organic FR additives derived from renewable raw materials can be categorized into the following chemical classes:

[0049] a) Carboxylic acid esters and alcohols;

[0050] b) Amines, alkanolamines, amides, and imides;

[0051] c) Polymers;

[0052] d) Ionic liquids (IL).

[0053] Of the carboxylic acid esters and alcohols, a) the most well-known and widely used to date are those derived from vegetable oils.

[0054] These substances, such as stearic acid and oleic acid, possess the dual characteristics of being "environmentally friendly" and derived from renewable raw materials, but they also have the drawback of causing potential corrosion, making them incompatible with engine lubricants (ICE). See, for example, Hugh Spikes, "Friction Modifier Additives", Tribol Lett (2015) 60:5, DOI10.1007 / s11249-015-0589.

[0055] Other FRs derived from vegetable oils that were used in the past were monoglycerides, such as GMS (glyceryl monostearate) and GMO (glyceryl monooleate).

[0056] In recent years, modifications to vegetable oils, such as epoxidation, esterification, acylation, hydrogenation, and alkylation, have been proposed to improve their friction-reducing properties. See, for example, the article Sharma BK, Doll KM, Erhan SZ, "Ester hydroxyderivatives of methyl oleate: tribological, oxidation and low temperature properties.", Bioresour Technol 2008;99:7333.

[0057] They also proposed an "environmentally friendly" product derived from the epoxidation of unsaturated fatty acid methyl esters, which has a strong enough interaction with the metal surface to provide good friction reduction properties (Sharma BK, Doll KM, Erhan SZ. "Oxidation, friction reducing, and low temperature properties of epoxy fatty acid methylesters", Green Chem 2007; 9:469).

[0058] Other fuels considered "environmentally friendly" are products derived from the condensation of certain polycarboxylic acids, such as tartaric acid or citric acid, with fatty alcohols and / or fatty amines (see, for example, US 2011 / 0162263 A1).

[0059] Although ester derivatives obtained from the reaction of polycarboxylic acids and fatty alcohols are soluble in both fuels and lubricants, they actually have low friction-reducing properties due to their weak "binding" interaction with the metal surfaces they come into contact with and their lack of "polar" sites.

[0060] On the other hand, amide derivatives obtained by reacting polycarboxylic acids with fatty amines are generally not very soluble in lubricants / fuels, and therefore cannot be effectively used as friction reducers.

[0061] Another renewable source for building environmentally friendly fuels is sugar and more generally carbohydrates.

[0062] For example, esters derived from the esterification or transesterification of sorbitol with fatty acids or fatty acid esters have been proposed (see, for example, US 2010 / 0210487 A1) to achieve functionalization at the primary hydroxyl group, as shown in the figure below:

[0063]

[0064] Among amines, alkanolamines, amides, and imides (b) that can reduce friction, aliphatic amines derived from renewable raw materials and amino alcohol esters derived from fatty acids described in US 2010 / 0132253 A1, having the following formula, may be mentioned.

[0065]

[0066] Furthermore, the highly polar portion is missing in this molecule, which is destined to be used as fuel, which impairs surface bonding.

[0067] Another example of product class b) is an amino alcohol derived from fatty amines and glycerol derivatives, such as those obtained by reacting derivatives of 1,2-propanediol with fatty amines, represented by the following formula.

[0068]

[0069] The products described in US4816037 are particularly effective in reducing friction, but the downside is that they are derived from fatty amines and toxic compounds such as glycidol or chloropropanediol.

[0070] Amides and alkanolamides are also known to be used as fuel FRs, such as those described in US2007 / 0094921A1: oleylamides, which can be considered the progenitor of this group, are very effective in reducing friction, but have been shown to be difficult to dissolve in lubricating oils in tests conducted.

[0071] In reality, lubrication is a complex process, and additives, lubricants, or combinations thereof are not necessarily stable and effective under all conditions.

[0072] The use of imides as additive friction modifiers in transmission fluids was also investigated, particularly those based on succinimides with oil-soluble hydrocarbon chains and having structures similar to the following:

[0073]

[0074] These molecules may be suitable for transmission fluids, but less so for "PCMO" (car engine oil) lubricants, in which, in addition to solubility in the lubricant (usually due to ends of suitable length, such as at least 16 but no more than 24 carbon atoms), additives with strong surface bonding ability (usually due to strongly polar ends) are preferred.

[0075] In polymer c), recently commercialized polymer products may be mentioned, such as Croda (trade name: Perfad), which is a polyester with a complex structure containing only carbon, hydrogen and oxygen.

[0076] However, for such products, the retention of friction-reducing properties after lubricant aging (oxidation test) is unsatisfactory.

[0077] In addition, a common drawback of polymer products is that they are not highly biorenewable.

[0078] In ionic liquids (ILs), these are salts with low melting temperatures and are liquids at room temperature, such as compounds based on alkylimidazolium salts, which have the following formula:

[0079]

[0080] However, the presence of BF4 and PF6 anions promotes water absorption, which subsequently hydrolyzes to form hydrofluoric acid, leading to corrosion and thermochemical reactions (Phillips B, Zabinski J. "Ionic liquid lubrication effects on ceramics in a water environment.", Tribol Lett 2004;17:533). Furthermore, the halogens contained in the anions can lead to the formation of hydrogen halides, which are corrosive and highly toxic to the environment.

[0081] Due to its complex synthesis process, in addition to its relatively high production cost, ILs typically also have the disadvantage of low biorenewability.

[0082] Therefore, the possibility of preparing cheaper ILs based on ammonium alkylbenzene sulfonate with the following structure has been evaluated.

[0083]

[0084] However, the presence of sulfur limits its use in "low saps" lubricants.

[0085] Therefore, there is a need for friction-reducing additives with high biorenewability for use in lubricating oils, including those with "low saps" and "medium saps," and also advantageously for use in fuels, which have one or more of the following properties:

[0086] -Contains no metals;

[0087] - Sulfur-free;

[0088] - Phosphorus-free;

[0089] - Does not contain halogen-containing anions;

[0090] -stability;

[0091] - Not obtained through toxic substances;

[0092] -Solubility in lubricating oils and fuels;

[0093] - The ability to maintain friction-reducing properties over a long period of time;

[0094] - Obtained through a simple process. Summary of the Invention

[0095] Therefore, one object of the present invention is to provide a friction-reducing additive that overcomes the disadvantages of the prior art and has one or more of the above-mentioned properties.

[0096] Another objective is to provide a friction-reducing additive that is highly biorenewable, exhibits solubility in lubricants and fuels, as well as high stability, and is able to pass each of the aforementioned friction tests, particularly showing an improved (i.e., lower) Stribek coefficient of friction (SFC) compared to commercially available nonmetallic OFr.

[0097] Another object of the present invention is to provide a method for preparing such friction-reducing additives, which is simple, economical and easy to manage.

[0098] For these purposes, the present invention relates to a friction-reducing additive suitable for lubricating oils (including "low saps" and "medium saps") and fuels, wherein the additive is free of metals or sulfur and phosphorus, and is in the form of a mixture comprising the following organic compounds:

[0099] Amides of formula (III),

[0100] -and / or

[0101] - One or more carboxylic acid esters of formula (IV),

[0102] and

[0103] Oxazolin of formula (V),

[0104] As described below, relative to the total weight of the mixture, the oxazoline content is greater than 7% by weight, preferably at least 9% by weight, wherein 100% of the remaining portion is represented by amide (III) and / or ester (IV), more preferably 100% of the remaining portion is composed of amide (III) and one or more esters (IV).

[0105] In fact, the applicant has found that the addition of oxazoline (V) to compounds (III) and / or (IV) unexpectedly improves the solubility of compounds (III) and / or (IV), as improvements in the stability of the additive in lubricants and fuels, as well as improvements in friction reduction, have been observed. See examples.

[0106] If the mixture has three components, namely oxazoline, amide and ester, the mixture may advantageously be the product of an autocatalytic condensation reaction of a carboxylic acid (preferably a fatty acid (saturated or unsaturated)) with a primary amino alcohol, wherein preferably at least one of the two reagents is from a renewable source.

[0107] In particular, one object of the present invention is a mixture of organic compounds derived from a fatty carboxylic acid (saturated or unsaturated) or synthetic carboxylic acid (synthetic) of plant or animal origin (preferably derived from renewable sources), or a mixture thereof with fatty acids of plant, animal or synthetic origin (synthetic), also simply referred to as CA:

[0108] (I)

[0109] in

[0110] -R is a group selected from straight-chain or branched alkyl or straight-chain or branched alkenyl groups having 2 to 40 carbon atoms, preferably 2 to 28, more preferably 2 to 20;

[0111] Autocatalytic condensation reaction with amino alcohols (AO) of formula (II) as follows:

[0112] (II)

[0113] The R1 and R2 groups may be the same or different from each other, and are independently selected from hydrogen, hydroxymethylene (-CH2OH), and straight-chain or branched hydrocarbon groups based on carbon and hydrogen (and without heteroatoms) having the following formula: C n H 2n+1 C n H 2n C n H n Where “n” is an integer that can vary between 1 and 40, preferably in the range of 8-12.

[0114] In a preferred embodiment of the invention, the acids of formula (I) may be pure or mixed with each other, and may be saturated or unsaturated.

[0115] In another preferred embodiment, the group R of the carboxylic acid (I) is an alkyl or alkylene group having at least 8 carbon atoms, preferably at least 12, more preferably at least 16, and preferably having a straight chain.

[0116] When component (I) is of plant and / or animal origin, it typically appears as a mixture of similar fatty acids: for example, in the case of oleic acid, it would be a mixture of at least three or four similar C6 fatty acids. 16 –C 20 A mixture of compounds.

[0117] If the carboxylic acid (I) is synthetic, the acid is considered to have a certain technical grade, typically at least 95% by weight, because it is mixed with a minimum amount of one or at most two other compounds as an upper / lower analogue.

[0118] In a preferred embodiment of the invention, the amino alcohol (II) used is ethanolamine (R1, R2 = H) and enantiomeric or racemic aminopropanediol (R1 = H, R2 = -CH2OH) or its isomers (R1 = -CH2OH, R2 = H), which are also referred to as APD below for simplicity.

[0119] As described above, the organic compound mixture of the present invention includes

[0120] -Amides of general formula (III) (AM-AO),

[0121] (III)

[0122] and / or

[0123] - One or more esters of general formula (IV) (E-AO)

[0124] (IV)

[0125] and

[0126] -Oxazoline of general formula (V) (OX-AO)

[0127] (V)

[0128] The R, R1, and R2 groups present in the structures of formulas (III), (IV), and (V) have the meanings described above for formulas I and II.

[0129] In a preferred embodiment of the present invention, the organic compound mixture of the present invention comprises the three compounds shown in formulas (III), (IV), and (V) above, and is preferably obtained by a condensation reaction between the above-described carboxylic acid (I) and alkanolamine (II).

[0130] The amide of formula (III) is present in the above-described mixture of the present invention at a concentration of 1% to 90%, more preferably 20% to 85%, and even more preferably 30% to 75% (expressed as a weight percentage relative to the total weight of the mixture).

[0131] The mixture of the present invention is present in the above-described mixture at a concentration of 1% to 60%, more preferably 3% to 30%, and even more preferably 5% to 20% (expressed as a weight percentage relative to the total weight of the mixture).

[0132] The oxazoline of formula (V) is present in the mixture of the present invention at a concentration of 9% to 80%, more preferably 15% to 70%, and even more preferably 20% to 50% (expressed as a weight percentage relative to the total weight of the mixture).

[0133] In a preferred embodiment, the mixture of the present invention comprises (by weight %) relative to the total weight of the total mixture.

[0134] -30% to 75% amide (III);

[0135] -5% to 20% ester (IV)

[0136] -20% to 50% of oxazoline (V).

[0137] If the additive of the present invention is a product of a condensation reaction, the concentration of one component in the above mixture relative to the other two components will depend on the operating conditions of the preparation process (time, temperature, solvent, molar ratio, equivalence ratio between amino alcohol (II) and carboxylic acid (I), which will be described in detail below.

[0138] In a preferred embodiment of the invention, the mixture comprises the following organic compounds:

[0139] - Amide (III) of specific formula (VI), also abbreviated as "AM-APD".

[0140] (VI)

[0141] and / or

[0142] - The ester (IV) of formula (VII) is also simply referred to as "E1-APD" (first ester).

[0143] (VII)

[0144] and / or

[0145] - Ester (III) of formula (VIII), also simply referred to as "E2-APD" (second ester).

[0146] (VIII)

[0147] and

[0148] -Oxazoline (V) of formula (IX), also abbreviated as "OX-APD"

[0149] (IX)

[0150] In all of the above formulas (from VI to IX), R has the meaning described above for formulas I and II, and preferably R is a hydrocarbon chain derived from oleic acid.

[0151] In one embodiment, the additive of the present invention may be a mixture of oxazoline (IX) and only one of the components shown in formulas (VI), (VII), and (VIII), or a mixture of oxazoline (IX) and a combination of components (VI), (VII), and (VIII).

[0152] In another preferred embodiment, the mixture contains all components (VI), (VII), (VIII), and (IX), and is preferably obtained by the condensation reaction described above, starting from a carboxylic acid (I) and an amino alcohol (II) or aminopropanediol (R1=H, R2=-CH2OH).

[0153] In another preferred embodiment of the invention, the mixture comprises the following organic compounds

[0154] -Amide (III) of specific formula (X)

[0155] (X)

[0156] and / or

[0157] -Ester (III) of specific formula (XI)

[0158]

[0159] (XI)

[0160] and

[0161] -Oxazoline (V) of specific formula (XII) (XII)

[0162]

[0163] (XII)

[0164] In all of the above equations (from X to XII), R has the meaning described above for equations I and II.

[0165] In one embodiment, the additive of the present invention may be a mixture obtained by the condensation reaction of carboxylic acid (I) and ethanolamine as an amino alcohol (II).

[0166] The applicant has surprisingly discovered that this additive, formed from a mixture of compounds of general formulas (III), (IV), and (V) according to the present invention, exhibits the following properties and advantages:

[0167] - The complete solubility of the mixtures of this invention in lubricating oils and fuels: This is unexpected considering the presence of amide compounds (which are generally not very soluble). Lubricants containing the mixtures of this invention have indeed proven to be transparent and free of deposits, especially when containing high concentrations of oxazoline;

[0168] - High friction-reducing ability in lubricant and fuel formulations: This is unexpected because oxazoline itself does not have friction-reducing properties.

[0169] In fact, unlike the techniques reported in the known art, this additive, composed of a mixture of compounds of the above general formulas (III), (IV), and (V), can satisfy all the following desired properties of friction-reducing additives:

[0170] - Organic additives that do not contain metal compounds, sulfur, and phosphorus (i.e., mixtures of organic compounds as defined above) are suitable for lubricant technologies with medium (medium saps) and low (low saps) sulfate ash, phosphorus, and sulfur content, and can significantly reduce friction when used in fuels and lubricants.

[0171] - A biorenewable additive because it can be obtained from biorenewable raw materials such as oleic acid and aminopropylene glycol, as well as from ammonia and ethylene oxide, which is produced by the oxidation of ethylene (bio) and then by the dehydration of (bio)ethanol.

[0172] Other advantages of the organic compound mixtures of the present invention can be summarized as follows.

[0173] The first advantage comes from the comparison of the friction-reducing properties of the mixture of the present invention with those of known art compounds, such as those reported in U.S. Patent US9562207, which claims an organic friction-improving additive that does not contain any metal elements, the additive being formed from a mixture of aliphatic alkanolamides obtained from alkanolamines (e.g., bis-2-hydroxypropylamine) containing a secondary hydroxyl group on an amino-alkyl substituent.

[0174] See the comparative example, in which the commercial product Lanxess MLA-3202 is used as the compound in patent US9562207.

[0175] As demonstrated by the examples, the mixture of compounds of the object of the present invention imparts a lower Stribek coefficient (SFC) value to the lubricant compared to a lubricant containing the Lanxess MLA-3202 additive and another lubricant containing a second commercial OFr-C (i.e., ethoxylated C12-14 alkoxy polyoxypropylene-2-propylamine) called Jeffadd FR-785.

[0176] The mixtures for which this invention is intended also have the advantage of being usable as both fuels and lubricants, whereas many known additives are labeled as being used only as lubricants and not as fuels, such as the Lanxess MLA-3202 product described in US9562207.

[0177] As described above, this additive can be obtained by mixing previously prepared components separately, or more conveniently by a condensation reaction between a carboxylic acid (I) and an alkanolamine (II) as defined above.

[0178] Therefore, another object of the present invention is a method for producing the friction-reducing additive formed from a mixture of compounds of the above general formulas (III), (IV) and (V) by reacting a fatty acid (I) and an alkanolamine (II) as defined above, the method comprising the following steps:

[0179] a) In the presence of an organic solvent immiscible with water, a condensation reaction is carried out between a fatty acid or mixture of fatty acids of formula (I) as defined above and an amino alcohol of formula (II) as defined above to form a mixture of products containing compounds of general formulas (III), (IV) and (V), wherein the amount of oxazoline (V) is greater than 8 by weight.

[0180] Advantageously, in order to obtain a mixture separated from the water formed during the condensation reaction, and a mixture separated from the unreacted reagent and the organic solvent used, step (a) is followed by one or more separation steps, which are carried out without removing one or more compounds of general formulas (III), (IV) and (V) from the mixture.

[0181] In particular, the following steps are advantageously performed sequentially after step (a).

[0182] b) Remove water from the mixture obtained in step (a);

[0183] c) The mixture obtained in (b) is distilled under vacuum to remove the reaction organic solvent, typically at a lower temperature relative to steps (a) and (b);

[0184] d) Remove unreacted amino alcohols from the mixture obtained in (c), for example by distillation at a higher vacuum than in step (c) without increasing the temperature, or by washing;

[0185] If an organic solvent with a boiling point higher than that of the amino alcohol is used, step (d) may optionally be performed before step (c).

[0186] The steps (a), (b), (c), and (d) of the method of the present invention can be carried out continuously in the same reactor or in different reactors, preferably in the same reactor.

[0187] Steps (a) and (b) can be advantageously performed simultaneously, under the same temperature and pressure conditions.

[0188] As an example of a reactor, we can cite a CSTR reactor equipped with a steam line and a condenser.

[0189] Furthermore, the reactor can be managed in a discontinuous and continuous manner: in the first case, once the reagents are loaded, the reaction is expected to be completed, and once the separation operation described above has been performed, the product is recovered from the bottom.

[0190] In the second case, the discharge of reaction products and the supply of reagents are carried out continuously to maintain a constant reaction volume inside the boiler.

[0191] The condensation step (a) is carried out in the absence of a catalyst at a temperature of at least 100°C, preferably 100°C-110°C to 220°C, more preferably 150°C-160°C to 200°C.

[0192] Furthermore, the condensation reaction in step (a) can be carried out under a pressure range of 1 to 5 bar absolute, preferably 1 to 2 bar absolute, and more preferably 1 to 1.2 bar absolute.

[0193] In one implementation, step (a) is performed at at least 160°C and atmospheric pressure.

[0194] The time required for the reaction in step (a) to proceed such that the amino alcohol is cyclized and to obtain an oxazoline content of more than 7% by weight in the mixture of reaction products is: depending on the working conditions (temperature, pressure, molar / equivalent ratio between reagents, type of solvent), it can be between 4 hours and 40 hours, preferably between 4 hours and 15-24 hours, more preferably between 7 hours and 10 hours, even though this is not restrictive to the purposes of the present invention.

[0195] Clearly, all other things being equal, the longer the reaction time, the higher the content of oxazoline (V) in the mixture.

[0196] In fact, the reaction in step (a) is considered complete when water is no longer produced, water being a stoichiometric byproduct that accompanies the formation of all three compounds (ester, amide, oxazoline) that make up the subject mixture of this invention.

[0197] In step (a), as described above, the carboxylic acid (I) may be saturated or unsaturated.

[0198] The preferred saturated carboxylic acid of formula (I) can be selected from decanoic acid, lauric acid, myristic acid, stearic acid, isostearic acid, arachidic acid, behenic acid and lignotaric acid.

[0199] The preferred unsaturated carboxylic acid of formula (I) may be selected from myrcene acid, myristoleic acid, palmitic acid, oleic acid, cod oleic acid, erucic acid, linoleic acid and linolenic acid.

[0200] In a preferred form, a carboxylic acid (I) or fatty acid of a biologically renewable source is used, with oleic acid of animal and plant origin being the most preferred fatty acid, optionally mixed with other carboxylic acids.

[0201] Examples of mixtures of oleic acid with other carboxylic acids include the following three mixtures with the following compositions:

[0202]

[0203] The preferred formula (II) amino alcohol used in step (a) may be selected from ethanolamine and aminopropanediol (specific isomers or mixtures of isomers), both of which are of fossil and biologically renewable origin, in the form of mixtures of isomers or as individuals.

[0204] In a preferred form, the amino alcohol used is aminopropanediol (APD): the product is a viscous compound with a purity of over 99%; the remaining portion (about 1%) consists of the corresponding isomer, referred to as "serine alcohol".

[0205] In step (a), the amount of amino alcohol (II) used (expressed as the ratio of the equivalent of amino alcohol (II) to the equivalent of carboxylic acid (I)) is preferably 1 to 2, more preferably 1.05 to 1.4, and even more preferably 1.1 to 1.35, even though these values ​​are not binding on the purpose of the present invention.

[0206] In fact, higher quantities can be used to facilitate the formation of oxazoline in a short time, even if such conditions are not preferred.

[0207] The water-immiscible reaction solvent in step (a) may be selected from those solvents whose boiling point is equal to or higher than the reaction or working temperature of the condensation reaction between carboxylic acid (I) and amino alcohol (II). The working temperature is given by the boiling point of the mixture. In any case, the working temperature must be at least the lowest temperature at which the stoichiometric amount of water produced from the various condensation reactions is removed.

[0208] The water-immiscible organic solvent in step (a) is chemically inert in the condensation reaction and functions to homogenize the reaction mixture and distribute heat evenly among the reactants. It can preferably be selected from:

[0209] - Aromatic hydrocarbons with 6-16 carbon atoms, more preferably selected from toluene, xylene, and tetrahydronaphthalene or Solvesso™;

[0210] - Aliphatic or alicyclic hydrocarbons with 7-16 carbon atoms, more preferably decane or decahydronaphthalene;

[0211] - Alkyl ethers, aryl-alkyl ethers and aryl ethers having 8-16 carbon atoms, more preferably anisole, phenethyl ether and diphenyl ether;

[0212] - Or a mixture of them.

[0213] In a preferred embodiment, the organic solvent used in step (a) is anisole, phenethyl ether or diphenyl ether, xylene, n-decane, Solvesso™ or a mixture thereof.

[0214] The amount of reaction solvent added in step (a), expressed as a weight percentage of the solvent relative to the amount of reactants added, is preferably 10% to 500%, more preferably 20% to 100%, and even more preferably 25% to 40%.

[0215] In another preferred form, the reaction solvent is anisole, and the amount added corresponds to a weight percentage of 10% to 90%, preferably 30% to 70%, relative to all components of the reaction mixture.

[0216] The step (b) of removing stoichiometric amounts of reaction water is advantageously carried out simultaneously with the reaction step (a), for example, using a reactor with a vapor line flowing into a collection container equipped with a condenser for collecting the heterogeneous mixture of H2O and solvent: the solvent, which is typically less dense than water, will fall back into the reactor, ensuring the continued progress of the reaction.

[0217] Step (c) of distilling the reaction solvent from the reaction product is usually carried out at a lower temperature than steps (a) and (b), at a temperature of 90°C to 180°C, preferably 120°C to 160°C, and under a vacuum, for example by operating at a pressure of 500 mbar to 10 mbar, preferably 300 mbar to 20 mbar.

[0218] The recovered reaction solvent can then be reused in subsequent synthesis.

[0219] Step (d) to remove amino alcohol (II) from the reaction product (mixture) contained in the reactor represents a purification step aimed at removing molar excess of amino alcohol from the mixture: in fact, since amino alcohol is extremely hydrophilic, it is poorly compatible with its final application as an additive in lubricants and fuels.

[0220] This step (d) can be performed in various ways.

[0221] For example, in step (d), the pressure relative to step (c) can be reduced to below 20 mbar, preferably below 10 mbar, while continuing to provide heat.

[0222] Alternatively, after diluting the water in a hydrophobic organic solvent, the amino alcohol (II) can be removed from the reaction mixture by washing it with demineralized water.

[0223] In this case, the removal of amino alcohols can be advantageously carried out using a multiphase low-boiling-point water-solvent mixture consisting of 50% m / m (weight / weight) water and 50% m / m (weight / weight) hydrophobic solvent such as dichloromethane, carbon tetrachloride, diethyl ether, toluene, xylene, cyclohexane or combinations thereof.

[0224] The amount of water-solvent washing mixture added corresponds to a weight percentage of 10% to 90%, preferably 30% to 70%, relative to all components of the mixture (reaction product).

[0225] The washing process is repeated up to three times. At the end of each wash, the aqueous phase containing excess amino alcohol is removed by physical separation.

[0226] At the end of the washing process, the low-boiling-point hydrophobic solvent is removed by distillation.

[0227] In a preferred embodiment, excess amino alcohol in step (d) is removed by distillation by utilizing the high boiling point difference between the amino alcohol and the mixture of organic compounds constituting the reaction product.

[0228] At the end of step (d) of the purification of the reaction product, a mixture containing a group of organic compounds having general formulas III, IV, and V is obtained, the amount of carboxylic acid initially present or fed is completely converted, and there is total selectivity (relative to acid) for the three types of organic compounds that form the mixture of the present invention.

[0229] Clearly, by changing the operating conditions (time, temperature), solvent type, and molar ratio of reactants, the reaction can be pushed toward various products that make up the mixture of organic compounds.

[0230] For example, at a temperature of 160°C to 200°C, an absolute pressure of 1 to 2 bar, and a molar ratio (or equivalent) of 1.1 to 1.35 of amino alcohol / carboxylic acid (AO:CA), using anisole, phenethyl ether, or diphenyl ether as a solvent, and continuing for a time sufficient to convert the reactants, a mixture is obtained, wherein the components of the reaction product (mixture) are in particularly effective amounts for reducing friction.

[0231] -Amide III: 30% to 75%

[0232] -Ester IV: 5% to 20%

[0233] -Oxazoline V: 20% to 50%.

[0234] The method according to the present invention has a number of advantages, including:

[0235] - By appropriately applying process operating conditions (time, temperature, molar excess, amount of water removed from equilibrium), the composition of the reaction products can be controlled, and thus the potential for selectivity for the three types of compounds in the mixture can be controlled.

[0236] - There are no catalysts for the preparation of some known compounds (such as zinc salts like zinc acetate), mild operating conditions, and overall selectivity for the desired mixtures formed from three types of organic compounds;

[0237] - A high reagent / solvent ratio, i.e., reducing the use of solvents and using non-toxic types of solvents.

[0238] In particular, the absence of a catalyst eliminates the need for further purification steps to remove the catalyst from the mixture of the three components.

[0239] According to the invention, another objective also includes a lubricating composition (lubricating agent) comprising...

[0240] - Friction-reducing additives in the form of mixtures of compounds of general formulas (III), (IV) and (V) as defined above;

[0241] - Lubricating base oil or a mixture of lubricating base oils.

[0242] Without departing from the scope of the invention, the mixtures of the invention used as lubricant additives may be two-component mixtures (oxazoline and amide, or oxazoline and ester) or multi-component mixtures as described above.

[0243] Based on their chemical and physical properties and composition, base oils are classified into five categories.

[0244] One method of classifying base oils is defined by the American Petroleum Institute (API) in its publication "Engine Oil Licensing and Certification System" (API EOLCS, 1507 - Industry Services Department, 14th edition, December 1996, Appendix 1, December 1998).

[0245] According to this API classification, the base oils of the lubricating formulations that can be used for the purposes of this invention may belong to all of the above-mentioned API groups, preferably to API groups selected from II, III, IV, and V, and even more preferably to API groups III, IV, and V.

[0246] The base oil of the lubricating composition used for the purposes of this invention may be selected from mineral, synthetic, plant, animal-derived base oils and mixtures thereof.

[0247] Mineral-derived base oils are derived from known petroleum refining processes, such as distillation, dewaxing, deasphalting, dearomatization, and hydrogenation.

[0248] The base oils from which the synthesis is derived preferably include hydrocarbon oils, such as polymerized and hydrogenated terminal or internal olefins; alkylbenzenes; polyphenylene; alkylated diphenyl ethers; polyalkylene glycols and their derivatives, wherein the terminal hydroxyl groups have been modified, for example, by esterification or etherification.

[0249] Another type of synthetic lubricant preferably includes esters of synthetic carboxylic acids or carboxylic acids derived from animal or plant sources with various alcohols or polyols.

[0250] Another type of synthetic lubricant preferably contains carbonates containing various alcohols and polyols.

[0251] Preferably, the plant-based base oil is selected from soybean oil, palm oil, and castor oil, while the animal-based base oil is preferably selected from tallow, lard, and whale oil.

[0252] As described above, the mixture of the aforementioned organic compounds (Formulas III, IV, and V) has been shown to be an additive to base oils, capable of significantly reducing friction between relatively moving metal bodies, improving the energy efficiency of machinery, especially engines, and thus reducing carbon dioxide emissions.

[0253] In addition to mixtures of organic compounds of formulas III, IV and V of the present invention, the lubricating compositions of the present invention may contain one or more other various additives.

[0254] Such additives can be

[0255] - Detergent additives, such as neutral and highly alkaline calcium and magnesium alkylbenzene sulfonates, and calcium or magnesium salts based on calixarenes in detergents.

[0256] - Viscosity index improving additives

[0257] -Dispersant additives,

[0258] - Antioxidant additives,

[0259] - Organometallic friction modifiers

[0260] - Anti-wear and extreme pressure additives (EP additives)

[0261] -Corrosion inhibitors,

[0262] - Additives that lower the pour point

[0263] -Foam inhibitors,

[0264] - Emulsifiers and others.

[0265] The lubricating composition of the present invention contains a mixture of the above-mentioned compounds of formulas (III), (IV), and (V) as friction-reducing additives, and the total concentration is expressed as a weight percentage of the organic compound mixture to the total weight of the final lubricating composition, which is 0.1-50%, preferably 0.3-20%, even more preferably 0.5-5%, advantageously about 1%.

[0266] Another object of the present invention is a lubricating composition containing a mixture of organic compounds (III), (IV), and (V) as described above, for use as a highly fuel-efficient automotive lubricant and highly compatible with automotive exhaust aftertreatment devices to reduce pollutant emissions.

[0267] It is known that in order to reduce pollution emissions, motor vehicles must be equipped with exhaust gas treatment systems consisting of particulate filters and / or devices containing catalysts.

[0268] A small portion of the lubricating oil drawn from the combustion chamber contains elements such as sulfur and phosphorus, as well as metals such as calcium, magnesium, and zinc, which reduces the efficiency of these devices.

[0269] Vehicles equipped with gasoline engines are fitted with precious metal-based three-way catalytic converters to reduce CO, unburned hydrocarbons (HC), and nitrogen oxides (NOx). x Because elements such as sulfur and phosphorus poison the catalyst, this device suffers from a loss of efficiency.

[0270] Vehicles equipped with diesel engines are equipped with devices for controlling NO. x Emissions are catalytic systems (LNT or SCR units) and CO / HC (DOC units), both of which are sensitive to sulfur and phosphorus.

[0271] Diesel engines and more recently, direct-injection gasoline engines also require particulate filters, which can become clogged due to the presence of inorganic metal components (ash) generated from the combustion of lubricant in small amounts that enter the combustion chamber. The tendency of lubricant to form inorganic ash is indicated by the "sulfate ash" parameter.

[0272] To ensure the long-term efficiency of these emission treatment systems, the lubricant must therefore contain low levels of sulfate ash, sulfur, and phosphorus (low / medium SAPS oil, where SAPS refers to sulfate ash, phosphorus, and sulfur).

[0273] In engine oils, phosphorus mainly comes from anti-wear additives (ZDDP or zinc dialkyl dithiophosphate), while sulfur can come not only from anti-wear additives but also from lubricating base oils and detergent compositions, such as those based on calcium sulfonate.

[0274] The metals that produce ash mainly come from anti-wear additives, organometallic additives called "friction reducers," and detergent compositions.

[0275] The friction-reducing additive according to the present invention is free of metals, phosphorus, and sulfur, thus ensuring high compatibility with modern exhaust gas treatment devices.

[0276] As mentioned above, mixtures of organic compounds of formulas III, IV and V can also be added to fuels.

[0277] Another object of the present invention is a fuel formulation containing a mixture of organic compounds of formulas III, IV and V as described above, for use as a friction reducer in, for example, an Otto cycle internal combustion engine.

[0278] Without departing from the scope of the invention, the mixtures of the invention used as fuel additives may be two-component mixtures (oxazoline and amide, or oxazoline and ester) or multi-component mixtures as described above.

[0279] In a preferred embodiment of the invention, a mixture of the organic compounds for which the invention is intended is diluted in a solvent or solvent mixture to a total concentration (expressed as a weight percentage of the mixture of said organic compounds (III), (IV), (V) relative to the total composition of a solution consisting of the organic compound mixture + solvent or solvent mixture) of 1% to 75%, preferably 5% to 60%, even more preferably 10% to 30%, before being used in a fuel, particularly a gasoline formulation.

[0280] The solvent capable of dissolving and diluting mixtures of compounds (III), (IV), and (V) for the purposes of this invention may preferably be selected from:

[0281] - An alcohol containing 1-16 carbon atoms and having an acyclic or cyclic alkyl chain or an alkyl-aryl chain; more preferably selected from methanol, ethanol, propanol, isopropanol, butanol, cyclohexanol, 2-ethylhexanol, dodecyl alcohol, and benzyl alcohol;

[0282] - A polyhydroxy aliphatic hydrocarbon having 2-4 carbon atoms; more preferably selected from ethylene glycol, propylene glycol or glycerol;

[0283] - Dialkylene glycol or trialkylene glycol, wherein the alkylene contains 2-4 carbon atoms, more preferably selected from diethylene glycol, dipropylene glycol or triethylene glycol;

[0284] Monoalkylene glycol alkyl ethers of formula (XIII), or polyalkylene glycol alkyl ethers.

[0285] (XIII)

[0286] R8 is an alkyl group containing 1-6 carbon atoms; R9 is a divalent group containing carbon and hydrogen with 2-4 carbon atoms; R 10 It is hydrogen or an alkyl group having 1 to 6 carbon atoms; r is an integer from 1 to 6; more preferably it is monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether or tetraethylene glycol dimethyl ether, and mixtures thereof.

[0287] - Ketones having alkyl or alkylaryl or aromatic groups each containing 1-10 carbon atoms; more preferably selected from acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone or acetophenone;

[0288] - An ester of an aliphatic or aromatic carboxylic acid having 1-10 carbon atoms, more preferably selected from ethyl acetate and butyl acetate;

[0289] - Straight-chain or branched aliphatic or aromatic hydrocarbons with 4-40 carbon atoms;

[0290] - Lubricating base oil;

[0291] - and its mixtures.

[0292] The aromatic hydrocarbon solvent is preferably selected from benzene, substituted benzene, and mixtures thereof; more preferably, it is selected from toluene, xylene, and mixtures thereof.

[0293] The preferred solvent for the aliphatic hydrocarbon is aliphatic hydrocarbons with 4-30 carbon atoms and mixtures thereof.

[0294] The lubricating base oils that can be used to dissolve the mixtures of the organic compounds of the present invention are those already described above, and may belong to all of the above-mentioned API groups, preferably to API groups selected from I, II, III, IV, V (e.g., polyol esters), and even more preferably to API group V, especially those belonging to ester base oils.

[0295] According to the present invention, a single solvent can be used in the dissolution of a mixture of organic compounds (III), (IV), and (V).

[0296] In a preferred embodiment, a mixture of solubilizing solvents consisting of one or more of the aforementioned types of solubilizing solvents is used.

[0297] In a preferred embodiment, the solubilizing solvent mixture of the mixture of organic compounds (III), (IV), and (V) of the present invention is composed of a mixture selected from the following.

[0298] -A mixture of polyol esters and 2-ethylhexanol;

[0299] -A mixture of fatty acid esters and 2-ethylhexanol;

[0300] -A mixture of polyol esters and octanol;

[0301] -A mixture of fatty acid esters and octanol;

[0302] - A mixture of straight-chain or branched hydrocarbon compounds having 4 to 30 carbon atoms with 2-ethylhexanol;

[0303] - A mixture of straight-chain or branched hydrocarbon compounds with 4 to 30 carbon atoms and octanol.

[0304] In other preferred forms, the solubilizing solvent for the mixture of organic compounds (III), (IV), and (V) is a mixture of a straight-chain or branched hydrocarbon compound of 4 to 30 carbon atoms and 2-ethylhexanol, wherein the solubilizing solvent contains 10% to 80%, preferably 20% to 50%, more preferably 10% to 20% of an alcohol in weight percentage of the solvent mixture.

[0305] In another embodiment, the solubilizing solvent for the additive of the present invention comprises a mixture comprising:

[0306] - 10% to 50% by weight of C8 alcohol (e.g., 2-ethyl-1-hexanol) and 90% to 50% by weight of ester base oil (e.g., polyol ester) or C5-C 30 C5-C is preferred. 20 Even better, C5-C 15 A mixture of hydrocarbons.

[0307] The solution containing the friction-reducing additive of the present invention thus obtained is stable over a long period of time and can be added to fuels such as gasoline or diesel at a concentration of 1 to 10,000 ppm, preferably 10 to 1,000 ppm, or even more preferably 50 to 800 ppm, relative to the total weight of the final fuel composition.

[0308] In one embodiment, such a solution is present at a concentration of 400 to 800 ppm in the fuel.

[0309] Fuels with these additives can reduce friction in engine mechanical parts by reducing fuel consumption, thus offering an advantage over conventional fuel technologies.

[0310] Therefore, another object of the present invention is a fuel formulation containing a mixture of organic compounds III, IV and V, which can improve the energy efficiency of an engine. Attached Figure Description

[0311] Figure 1 Stability test images are shown for a reference blank sample (case a), a stable lubricant formulation (case b), and a formulation that failed the stability test (case c).

[0312] Figure 2 The Stribeck curves obtained from the MTM friction test of the lubricant composition at 45°C are shown.

[0313] Figure 3 The Stribeck curve of the lubricant composition obtained by MTM friction test at 120°C is shown.

[0314] Figure 4 The Stribeck curves obtained from the MTM friction test of the lubricant composition at 150°C are shown.

[0315] Figure 5 The trends in SRV testing of some lubricants with additives versus those without additives (blank sample) are shown.

[0316] Figure 6 A typical coupling for the HFRR test is shown.

[0317] Figure 7 An MTM device is shown, which is formed by a coupling with steel balls loaded on a disk. This device is used to measure COF at any slip / roll ratio up to 100% pure rolling.

[0318] Figure 8 The Stribeck curves under three different lubrication conditions are schematically shown. Detailed Implementation

[0319] Example

[0320] The composition of the reaction mixtures for the following preparation examples was monitored using the following analytical techniques: FT-IR analysis, HPLC analysis, and NMR analysis.

[0321] --FT-IR analysis

[0322] One analytical technique used to monitor reaction processes combines infrared (IR) and Fourier transform (FT).

[0323] Therefore, the instrument used (Perkin Elmer Frontier model) has a typical configuration in which an IR beam source illuminates the sample, and the sample transmits radiation to a detector for simultaneous recording of the corresponding interferogram.

[0324] Table 1: Typical IR absorption of compounds with formulas VI (AM-APD), VII (AM-APD), VIII (E2-APD), and IX (OX-APD)

[0325]

[0326] In formulas VI (AM-APD), VII (E1-APD), VIII (E2-APD), and IX (OX-APD), R is a hydrocarbon chain derived from oleic acid CH3(CH2)7CHCH(CH2)7COOH (see preparation examples).

[0327] HPLC analysis

[0328] Samples (reagent mixture and product mixture) analyzed by HPLC were prepared by completely removing the reaction solvent and diluting the same sample (1 wt%) in THF. The HPLC system used consisted of an HPLC pump, a small oven for column thermostating, a UV-Vis detector for HPLC, an autosampler, and a PC equipped with software for acquiring and processing chromatographic data.

[0329] Specifically, the system used was an Agilent 1260 HPLC Infinity II equipped with Chemstation software. The column used was an Agilent PLRP-S 100TO, 4.6 x 250 mm, 5 µm.

[0330] The HPLC method used provides the following operating conditions:

[0331] - Pump flow rate: 0.6 ml / min

[0332] -Visible UV detector wavelength: 210 nm

[0333] - Column constant temperature: 40°C

[0334] -Injection volume: 5µl

[0335] - Mobile phase: 60 mM acetic acid (A); acetonitrile (B); THF (C)

[0336] -Mobile phase composition (gradient): 0-20 minutes (A from 35% to 0%; B from 60% to 90%; C from 5% to 10%), 20-40 minutes (A from 0% to 35%; B from 90% to 60%; C from 10% to 5%).

[0337] A chromatogram typically contains multiple peaks, the areas of which are compared with the areas of standard solutions of known concentrations to construct a calibration curve for the analyte.

[0338] Table 2 below shows the typical signals used by the applicant to monitor the reaction using HPLC technology.

[0339] Table 2: Typical HPLC elution times for compounds with formulas VI (AM-APD), VII (E1-APD), VIII (E2-APD), and IX (OX-APD)

[0340]

[0341] NMR analysis

[0342] On the other hand, the chemical shifts of the functional groups characterizing the reagents and products covered by this notification were determined and confirmed by 13C-NMR (nuclear magnetic resonance) analysis.

[0343] The sample dissolved in CDCl3 was subjected to 13C-NMR spectroscopy using a Varian-500 instrument.

[0344] Table 3 reports the chemical shifts of the 13C signal used to verify the formation of the compound once the synthesis process of the following embodiments was completed according to the present invention.

[0345] Table 3: Typical chemical shifts of compounds with formulas VI (AM-APD), VII (E1-APD), VIII (E2-APD), and IX (OX-APD)

[0346]

[0347] As shown in Tables 1, 2, and 3, each analytical technique (e.g., IR, HPLC, and NMR) is selective for detecting some typical signals of products having structures VI, VII, VIII, and IX contained in the mixtures obtained in the preparation examples of the method according to the present invention.

[0348] A range of properties were evaluated by conducting a series of tribological laboratory tests and stability tests on lubricants and / or fuels containing the mixtures according to the invention, as described below.

[0349] - HFRR tribological test (applicable to gasoline)

[0350] The HFRR test is typically used for the "lubricity" of diesel fuel, measuring the wear amplitude and calculating the corresponding wear index (μm): the lower the value, the better the fuel performance.

[0351] According to the ISO 12156-1 standard applicable to gasoline, the test was conducted using a PCS instrument kit called the "HFRR Gasoline Conversion Kit" (which, during the test, limits gasoline loss due to the extreme volatility of gasoline itself).

[0352] The HFRR test is characterized by the following steps:

[0353] - Place the test fluid on the test plate;

[0354] - Place a steel ball on the test plate and apply horizontal motion, and

[0355] - Loading on steel balls (see...) Figure 6 , Figure 6 A typical coupling for the HFRR test is shown; in the above Figure 6 In the text: "Load" = load; "Stroke" = stroke; "Plate" = plate; "Fuel" = fuel; "Installation" = installation; "Wear Mark Size" = wear radius.

[0356] A low wear value indicates that the fuel has the best performance in terms of "lubricity" (the lubricating force generated by the fuel).

[0357] - SRV tribological test (For lubricant only)

[0358] A coupling similar to the HFRR test is used, but the test conditions are more stringent (predictable operating conditions based on internally developed methods):

[0359] - Load: 75–200 N

[0360] - Frequency: 25-50Hz

[0361] - Travel: 3 mm

[0362] -Time: 2 hours

[0363] At the end of the experiment, as the instrument response, the coefficient of friction (COF, dimensionless value - COF by ratio F) N / F F Given, where F N = Load applied to the sphere (N); F F =The lateral friction force generated by the friction between surfaces after horizontal oscillating motion) and the wear of the sphere are measured by microscope (mm).

[0364] In the same situation, low COF and wear values ​​indicate optimal lubricant performance.

[0365] - MTM Tribological Test (For lubricant only)

[0366] MTM devices allow you to measure COF at any slip / roll ratio, up to 100% pure roll.

[0367] These characteristics are derived from, for example Figure 7 The load is obtained from the coupling formed between the steel balls and the steel disc.

[0368] In such couplings, contact pressure and cutting speed can reach high values, very similar to those found in typical gears, rolling bearings, and cams of, for example, internal combustion engines (ICE).

[0369] All MTM tests reported in the examples were conducted at three different temperatures (45°C, 120°C, and 150°C), maintaining a load of 30 N and a slip / roll ratio of 50%.

[0370] This test can provide the possibility of qualitatively predicting the fuel economy of automotive lubricants by reconstructing the Stribek curve (which allows obtaining COF as a function of the sliding velocity generated between the contact surfaces) and calculating the Stribek coefficient of friction (SFC) (which provides an indication of the amount of energy absorbed).

[0371] In this application, under the following three different lubrication conditions, from a relatively high speed value (2 m / s, Figure 2-4 Starting from the beginning of the curve, gradually increasing until a very low value (where the velocity almost approaches zero (0.004 m / s)), a Stribek curve is constructed for each experimental composition. Figure 8 (Illustrated schematically).

[0372] More generally, COF trends can be studied under three different lubrication states (hydrodynamic, mixed, and boundary), which are determined by the thickness of the relative "friction film," which is understood as a lubricant film containing friction-reducing additives that is generated between contacting and relatively moving surfaces.

[0373] In fact, the additive can react chemically with the contact surface, resulting in a reduction in the coefficient of friction.

[0374] The three lubrication states described above are defined by parameter Λ, which is obtained by the ratio between the oil film thickness between the contact surfaces and their mean square roughness (the square root of the sum of the squares of the roughnesses of the two surfaces):

[0375] Λ = film thickness / mean square roughness

[0376] When the lubricant film (the middle layer in the attached diagram) is thick enough to completely separate the two surfaces (the opposite outer layers in the diagram below) and prevent contact between the two objects, a "hydrodynamic" state occurs, as illustrated schematically in the diagram below: In this case, the thickness of the film is therefore greater than the surface roughness, with a parameter value Λ of 5 to 100.

[0377]

[0378] Under hydrodynamic conditions, a low coefficient of friction (COF) value is given by the rheological properties of the lubricant, such as a high viscosity index and a low HTHS viscosity value (high temperature, high shear rate), which are measures of the apparent viscosity of multi-grade lubricants.

[0379] Such measurements were performed at high temperatures (150°C) and high shear rates (10). 6 s -1 (This will be carried out below.)

[0380] A "mixed" state occurs when the surface roughness of two objects in relative motion (indicated by arrows pointing in opposite directions in the diagram below) is very close, as shown in the diagram. This condition is typical of couplings using gears and roller / ball bearings, characterized by a parameter value Λ of 2 to 5.

[0381]

[0382] The boundary state determined by relatively low velocity is the formation of a low-thickness friction film between metal surfaces (represented by arrows pointing in opposite directions in the figure below), which leads to an increase in COF.

[0383]

[0384] Under boundary conditions, surface roughness and composition are the main causes of friction, while the viscosity of the lubricant has a relatively small effect on friction behavior.

[0385] The boundary state (Λ value less than 1) is characterized by a very high load (pressure) related to the sliding speed between surfaces.

[0386] The evaluation of the Stribek curve takes into account not only the obtained trend ( Figure 2 , 3 , 4), also according to M.Lattuada, M. Manni "A new methodology for the experimental evaluation oforganic antifriction additives"-10 th The method described in the INTERNATIONAL SYMPOSIUM ON FUELS ANDLUBRICANTS (incorporated in its entirety by reference) calculates the area under the same curve using the trapezoidal method.

[0387] The result of this integral is the Stribek coefficient of friction (SFC): a low SFC value corresponds to excellent fuel economy, which is due to the lubricant's ability to reduce friction between the various couplings present in the engine and transmission.

[0388] - Stability test

[0389] Stability testing is conducted qualitatively, visually assessing the presence (turbidity) or absence (clarity) of deposits in the lubricant formulation sample over a period of two weeks. Figure 1 ).

[0390] The absence of sediment indicates complete solubility of the additive in the lubricating oil.

[0391] - Examples 1-10 of additive preparation

[0392] All preparation examples 1-10 containing mixtures of organic compounds having general formulas (VI), (VII), (VIII), and (IX) were carried out using reactors equipped with steam lines to remove stoichiometric H2O from the reaction.

[0393] The steam line flows into a second collection container equipped with a condenser to collect the heterogeneous mixture H2O-solvent: the solvent, due to its lower density than H2O, falls back into the reaction vessel (boiler) to ensure the continuous progress of the reaction.

[0394] Once the reaction is complete, the solvent is removed and recovered for subsequent synthesis.

[0395] The final stage is refining, which aims to simply remove molar excess of amino alcohols, such as aminopropanediol, from the reaction products.

[0396] All experiments reported below were conducted under the following operating conditions:

[0397] 1) The temperature is 110℃ to 220℃, preferably 150-200℃;

[0398] 2) The reaction time is 5 to 24 hours, preferably 7 to 10 hours;

[0399] 3) The operating pressure is 1-2 bar absolute, preferably 1-1.2 bar absolute.

[0400] Example 1: Synthesis of PC01 mixture

[0401] In a reactor (volume = 500 mL) equipped with a steam line and a condenser, add the following respectively:

[0402] -Industrial grade oleic acid (90g; 0.33mol),

[0403] -Aminopropanediol (40 g, 0.43 mol) and

[0404] - Xylene (160g) as a solvent.

[0405] The operating pressure is atmospheric pressure.

[0406] The reaction mixture was heated to the reflux temperature of the solvent (approximately 160°C) for approximately 40 hours, and the amount of H2O formed (6.5 g) was monitored and continuously removed from the reaction environment.

[0407] Once the reaction was complete, the solvent was removed under vacuum, yielding approximately 122 g of solid product at room temperature.

[0408] The PC01 mixture thus obtained and the mixture obtained after water washing (APD removal) were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0409] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0410] Example 2: Synthesis of PC02 mixture

[0411] In a reactor (volume = 250 mL) equipped with a steam line and a condenser, add the following respectively:

[0412] -Industrial grade oleic acid (45g; 0.17mol),

[0413] -Aminopropanediol (20 g, 0.21 mol) and

[0414] - Phenethyl ether (75g) as a solvent.

[0415] The operating pressure is atmospheric pressure.

[0416] The reaction was heated to the reflux temperature of the solvent (approximately 175°C) for about 30 hours, and the amount of H2O formed (4 g) was monitored and continuously removed from the reaction environment.

[0417] Once the condensation reaction is complete, the reaction water is removed, the solvent is removed under vacuum, and approximately 60 g of solid product is obtained at room temperature.

[0418] The PC02 mixture thus obtained and the mixture obtained after water washing (APD removal) were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0419] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0420] Example 3: Synthesis of PC03 Mixture

[0421] In a reactor (volume = 250 mL) equipped with a steam line condenser, add the following:

[0422] -Industrial grade oleic acid (45g; 0.17mol),

[0423] -Aminopropanediol (20 g, 0.21 mol)

[0424] and

[0425] - 75g of n-decane as a solvent.

[0426] The operating pressure is atmospheric pressure.

[0427] The reaction was heated to the reflux temperature of the solvent (approximately 185°C) for about 30 hours, and the amount of H2O formed (4.1 g) was monitored and continuously removed from the reaction environment.

[0428] Once the reaction was complete, the solvent was removed under vacuum, yielding approximately 60 g of solid product at room temperature.

[0429] The PC03 mixture thus obtained and the mixture obtained after water washing (APD removal) were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0430] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0431] Example 4: Synthesis of PC04 Mixture

[0432] In a reactor (volume = 250 mL) equipped with a steam line and a condenser, add the following respectively:

[0433] -Industrial grade oleic acid (52g; 0.19mol),

[0434] -Aminopropanediol (20 g, 0.21 mol) and

[0435] - Solvesso™ 150 (90 g) as a solvent (a typical industrial solvent produced by Exxon Mobil).

[0436] The operating pressure is atmospheric pressure.

[0437] The reaction was heated to the reflux temperature of the solvent (approximately 195°C) for about 10 hours, and the amount of H2O formed (5.4 g) was monitored and continuously removed from the reaction environment.

[0438] Once the reaction was complete, the solvent was removed under vacuum. Due to the possibility of any remaining solvent, approximately 66 g of fluid product was obtained at room temperature.

[0439] The PC04 mixture thus obtained and the mixture after stripping residual APD were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0440] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0441] Example 5: Synthesis of PC05 Mixture

[0442] In a reactor (volume = 500 mL) equipped with a steam line and a condenser, add the following respectively:

[0443] -Industrial grade oleic acid (110g; 0.41mol),

[0444] -Aminopropanediol (40 g, 0.43 mol) and

[0445] - 75g of n-decane as a solvent.

[0446] The operating pressure is atmospheric pressure.

[0447] The reaction was heated to the reflux temperature of the solvent (approximately 185°C) for about 16 hours, and the amount of H2O formed (7.8 g) was monitored and continuously removed from the reaction environment.

[0448] Once the reaction was complete, the solvent was removed under vacuum, yielding approximately 140 g of solid product at room temperature.

[0449] The PC05 mixture thus obtained and the mixture obtained from the stripping residue APD were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0450] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0451] Example 6: Synthesis of PC06 Mixture

[0452] In a reactor (volume = 500 mL) equipped with a steam line and a condenser, add the following respectively:

[0453] -Industrial grade oleic acid (110g; 0.41mol),

[0454] -Aminopropanediol (40 g, 0.43 mol) and

[0455] - 75g of n-decane as a solvent.

[0456] The operating pressure is atmospheric pressure.

[0457] The reaction was heated to 150°C and held for 8 hours, followed by holding at 180°C for another 10 hours. The amount of H2O formed (7.5 g) was monitored and continuously removed from the reaction environment.

[0458] Once the reaction was complete, approximately 140 g of product was obtained after stripping the solvent, and the residual APD was then removed under vacuum.

[0459] The mixture obtained after solvent removal and the final mixture after stripping residual APD were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0460] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0461] Example 7 (contrast): PC07 mixture synthesis (Solvent-free and oxazoline-free)

[0462] In a reactor (volume = 250 mL) equipped with a steam line and a condenser, add the following respectively:

[0463] -Industrial grade oleic acid (52g; 0.19mol),

[0464] -Aminopropanediol (20 g, 0.21 mol).

[0465] The reaction mixture was heated to 110°C under reduced pressure (100 mbar) and held for 3 hours, then held at 160°C and 1 mbar for another 18 hours, followed by a further 16 hours at 180°C.

[0466] Once the reaction was complete, the resulting product was quantified, and its mass was approximately 61g.

[0467] The PC07 mixture thus obtained and the mixture obtained from the stripping residue APD were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0468] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0469] Example 8: Synthesis of PC08 Mixture

[0470] In a reactor (volume = 500 mL) equipped with a steam line and a condenser, add the following respectively:

[0471] -Industrial grade oleic acid (90g; 0.33mol),

[0472] -Aminopropanediol (40 g, 0.43 mol) and

[0473] - 85g of n-decane as a solvent.

[0474] The operating pressure is atmospheric pressure.

[0475] The reaction was heated to 185°C and held for 55 hours, and the amount of H2O formed (10g) was monitored and continuously removed from the reaction environment.

[0476] Once the reaction was complete, the solvent was removed under vacuum, yielding approximately 119 g of liquid product at room temperature.

[0477] The PC08 mixture thus obtained and the mixture obtained from the stripping residue APD were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0478] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0479] Example 9: Synthesis of PC12 mixture

[0480] In a reactor (volume = 500 mL) equipped with a steam line and a condenser, add the following respectively:

[0481] - Oleic acid of plant origin, with the composition shown in the table in the instructions (90g; 0.34 mol).

[0482] -Aminopropanediol (40 g, 0.43 mol)

[0483] and

[0484] - 85g of n-decane as a solvent.

[0485] The operating pressure is atmospheric pressure.

[0486] The reaction was heated to 185°C and held for 25 hours. The amount of H2O formed (8g) was monitored and continuously removed from the reaction environment.

[0487] Once the reaction was complete, the solvent was removed under vacuum, yielding approximately 120 g of solid product at room temperature.

[0488] The PC12 mixture thus obtained and the mixture obtained from the stripping residue APD were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0489] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0490] Example 10: Synthesis of PC13 Mixture

[0491] In a reactor (volume = 500 mL) equipped with a steam line and a condenser, add the following respectively:

[0492] -Oleic acid of animal origin, with the composition shown in the table in the instructions (145g; 0.54 mol).

[0493] -Aminopropanediol (56 g, 0.60 mol) and

[0494] - Anisole as a solvent (88 g; 0.81 mol).

[0495] The operating pressure is atmospheric pressure.

[0496] The reaction was heated to 170°C and held for 10 hours. The amount of H2O formed (13g) was monitored and continuously removed from the reaction environment.

[0497] Once the reaction was complete, the solvent was removed under vacuum to obtain approximately 187g of product.

[0498] The PC13 mixture thus obtained and the mixture obtained from the subsequent stripping residue APD were then characterized using common analytical techniques such as IR, HPLC and NMR reported in Tables 1, 2 and 3.

[0499] Table 4 shows the product selectivity (AM-APD, E1-APD, E2-APD, Ox-APD).

[0500] Based on data from the aforementioned analytical techniques, the reaction selectivity and residual concentration of molar excess APD can be quantified (Table 4).

[0501] In all embodiments, the conversion of oleic acid, as determined by IR analysis, is complete, and therefore the yield of the mixture product calculated relative to oleic acid is consistent with the selectivity.

[0502] Table 4: Reaction selectivity and residual APD, Examples 1–10

[0503]

[0504] The data reported in Table 4 pertain to the analysis of the mixture after solvent removal (and before removal of residual APD), from which the following parameters were determined:

[0505] 1) Selectivity (wt%) of reaction products (AM-APD, E1-APD, E2-APD, Ox-APD) by NMR analysis;

[0506] 2) Residual APD concentration (wt%) as analyzed by HPLC.

[0507] The mixture was then purified by washing with water (Examples 1, 2 and 3) or by low-pressure stripping (Examples 4-10), resulting in a residual APD concentration of less than 1% by weight in all cases (which can be measured by HPLC).

[0508] The results reported in Table 4 demonstrate that by varying the operating conditions (time, temperature), solvent type, and molar ratio of reactants, this method allows for selective targeting of a variety of products that make up a mixture of organic compounds.

[0509] Furthermore, data from Example 7 show that no oxazoline is formed during the condensation reaction when the process is operated outside the conditions according to the invention.

[0510] Examples 11-13 (comparative) and 14-23: Formulation preparation, stability testing and friction testing

[0511] All product mixtures obtained in Examples 1-10 were subsequently used as FR additives in typical “PCMO” (Passenger Vehicle Engine Oil) formulations of SAE0W-20 grade.

[0512] To compare all the additives prepared in Examples 1-10, lubricant formulations were prepared using the following method.

[0513] Friction reducer FR is added as a final additive to the "master mixture" (MM) consisting of lubricant, viscosity modifier and PPD (pour point depressant), with the concentration of friction reducer equal to 1 wt% relative to the total mixture.

[0514] MM's lubricant is a mixture of a Group III base oil and a Part Package Additive Package (PP), which contains all the additives commonly found in lubricants except for FR friction modifiers (dispersants, detergents, antioxidants, anti-wear agents).

[0515] Therefore, MM contains a total of (by weight):

[0516] -83% to 85% Group III base oil (API classification) (kinematic viscosity at 100°C = 4 cSt);

[0517] -3% to 4% viscosity modifier VM (styrene-butadiene copolymer in Group III base oils);

[0518] -0.1% to 0.5% PPD (pour point depressant), composed of polyalkyl methacrylates from Group I base oils;

[0519] -10.5% to 11.5% of the Part Package.

[0520] In this way, the final formulations of the lubricating compositions reported in Table 5 below (Examples 11-23) were obtained for qualitative stability testing (yes / no) and tribological testing reported below.

[0521] Table 5: Lubricants used for stability and friction tests

[0522]

[0523] All the lubricants listed in the table have the same viscosity range because their formulations conform to the "SAE 0W-20" grade (the range of their property values ​​is listed in the SAE J300 table).

[0524] The first three lubricants (as shown in Table 5 (Mix 35 / 19, Mix 36 / 19, Mix 10 / 19)) are used as references, i.e. as comparative examples that do not constitute part of this invention.

[0525] Mix 35 / 19 (Comparative Example 11) does not contain additive friction modifiers, while Mix 36 / 19 and Mix 10 / 19 (Comparative Examples 12 and 13) contain commercially available organic friction modifiers.

[0526] - In (Mix 36 / 19): OFr-C (Jeffadd FR-785), which is composed of alkyl polyetheramine and ethylene oxide (ethoxylated C). 12 -C 14 The composition of a given compound that reacts with alkoxypolyoxypropylene-2-propylamine;

[0527] - In (Mix 10 / 19): MLA-3202 (C) synthesized by condensation of carboxylic acids and non-primary alkanolamines as described in patent US9562207 16 and C 18 Fatty acid esters and C 18 The amidation product of unsaturated fatty acid esters and 1,1'-aminodiprop-2-ol; the CAS number provided in the MLA-3202 product safety data sheet is 1454803-04-3, through which it can be traced back to the defined friction-reducing additive).

[0528] The latter two commercially available products differ from the mixture according to the invention in that they are linear and do not contain oxazoline cyclic compounds.

[0529] From a qualitative perspective, the results of a stability test (with a time span of two weeks) can be observed... Figure 1 The image shown is better understood and represents

[0530] -Refer to blank (Example 11; Mix 35 / 19 -) Figure 1 Case a);

[0531] -All stable lubricants: Figure 1 Only the sample of Example 18 is shown; Mix 39 / 19 - PC02 - Y - Case b) is also shown as a representative visual example of other stable lubricant formulations Y in Table 5;

[0532] - All formulations that failed stability testing: In Figure 1 Only the sample of Example 21 is shown in Table 5; Mix 42 / 19-PC05-N-Case c) serves as a representative visual example of other unstable lubricant formulations N in Table 5.

[0533] The stability tests of the lubricants in Table 5 have demonstrated that the stability of the formulations of the present invention is strongly dependent on the presence (Comparative Example 20) and concentration of the oxazoline compound “OX-APD”: in fact, it appears that high concentrations of “OX-APD” in the mixture forming the friction-reducing additives allow for the acquisition of lubricating formulations with long-term stability.

[0534] Examples 23-35: MTM Experiments and Calculations of Stribek Coefficient (SFC) at Three Different Temperatures

[0535] According to the above method, MTM friction tests were performed on all the lubricants listed in Table 5. Figure 2 , 3 4).

[0536] from Figure 2 , 3 As can be seen from 4, the trend difference between the reference lubricant (Mix 35 / 19) and the lubricant with additives is smallest at low temperature (45°C) and larger at high temperature (120°C, 150°C).

[0537] This is a typical characteristic of organic friction reducers. At medium to high temperatures (around 80°C), organic friction reducers are often activated, thereby reducing the coefficient of friction (COF).

[0538] To better understand which additive contributes the most, the Stribek coefficient (SFC) for each curve across all three temperature ranges (45°C, 120°C, and 150°C) was calculated using the trapezoidal method (see above).

[0539] The results obtained from the treatment of the compositions of Examples 23-35 are shown in Table 6.

[0540] Table 6: Stribek coefficients obtained at three different temperatures

[0541]

[0542] As can be seen from Table 6, Mix 39 / 19 (Example 27) with PC02 and Mix 40 / 19 (Example 28) with PC03 are characterized by a low “SFC” value compared to the reference lubricant mixture 35 / 19 (Comparative Example 23).

[0543] It should be noted that Mix 39 / 19 with PC02 and Mix 40 / 19 with PC03 have also been shown to be deposit-free lubricants because they are transparent, similar to... Figure 1 The Mix 35 / 19 shown is stable (see Table 5).

[0544] In fact, all lubricants that appear to be stable are visually identical to Mix 35 / 19 and Mix 39 / 19-PC02 (i.e., as shown). Figure 1 The lubricant shown is transparent or substantially transparent, while all lubricants that appear unstable are visually identical to Mix 42 / 19-PC05 (Example 30), i.e., have the same properties as shown. Figure 1 The sediments and turbidity are shown.

[0545] The same stability and SFC results were also observed in lubricant additives containing the friction-reducing additives of the present invention (Example 34: Mix 53 / 19 and Example 35: Mix 55 / 19), which are obtained from commercially available plant and animal carboxylic acids.

[0546] In fact, considering the stable compositions in Table 6, it can be noted that the SFC values ​​obtained in tests 26-35 were generally lower than the control values; that is, in tests 26-35, some values ​​were significantly lower than those of lubricants with commercially available OFR additives. This was more pronounced at higher temperatures, also because 45°C is considered a “cold” temperature at which the additives are less active.

[0547] The results reported under the underlined font were considered to be worse than (better than) the comparison results.

[0548] Examples 36-47: SRV Trials

[0549] Further in-depth friction tests were conducted on the lubricants listed in Table 5 using the “SRV” instrument (see characterization above).

[0550] The instrument used in this test is generally more sensitive to the presence of organometallic “anti-friction” but is also used in “non-damaging” tests, in which a lubricant with additives is compared to a reference “blank” (Mix 35 / 19).

[0551] Table 7 shows the results of the SRV test.

[0552] Table 7: COF and Wear Values ​​from SRV Tests

[0553]

[0554] Figure 5 The trends in the SRV tests shown and the relative values ​​shown in Table 7 demonstrate how the lubricant with the mixture of the present invention gives a slightly lower COF value than the reference "blank" (Mix 35 / 19).

[0555] Similarly, for the SRV test, the best results, namely the lowest COF value (shallower inner pillar) and the lowest wear value (deeper outer pillar), were obtained using the same series of lubricating compositions according to the invention (Mix 39 / 19, Mix 40 / 19, Mix 53 / 19, Mix 55 / 19, where the COF values ​​are underlined in Table 7), which are characterized by low SFC values ​​in the MTM test (see Table 6).

[0556] Examples 48-54: HFRR test of hydrocarbons with added COF reducer

[0557] Further studies have been conducted in other hydrocarbon fluids (fuels) (e.g., gasoline) with the addition of a mixture of PC02, PC12 and PC13, which has proven particularly advantageous in lubricants.

[0558] Specifically, the above-mentioned "COF reducer" additive was appropriately dissolved and added to "Eni regular RON 95" gasoline, and then the corresponding HFRR tribological test was carried out on the gasoline.

[0559] The product consists of 10% to 50% by weight of a C8 alcohol (e.g., 2-ethyl-1-hexanol) and 90% to 50% by weight of a base ester (e.g., a polyol ester) or a product ranging from C5 to C6. 30 C5-C is preferred. 20 Even better, C5-C 15 The solvent is used to solubilize the mixture of hydrocarbons.

[0560] The concentrations of PC02, PC12, and PC13 in the solvent are 10% by weight or 20% by weight.

[0561] The fluid thus obtained was added to ordinary gasoline without additives at concentrations of 800 ppm by weight (Examples 50-52) and 400 ppm by weight (Examples 53 and 54).

[0562] The HFRR results of this experiment are shown in Table 8.

[0563] Table 8: HFRR test results of Examples 48 to 54

[0564]

[0565] As shown in the table, all additives PC02, PC12 and PC13 significantly reduced wear diameter compared to gasoline without additives (Example 48) and gasoline with additives containing only solvent mixtures.

[0566] This final test was conducted to evaluate the effect of the mixture (a mixture of compounds) used to dissolve the friction-reducing additive of the present invention on gasoline (Example 49) in terms of wear and COF.

[0567] Particularly effective are additives made with PC12 and PC13 at different ppm, namely mixtures of organic compounds obtained from plant-derived (PC12, Example 9) and animal-derived (PC13, Example 10) raw materials, particularly carboxylic acids.

[0568] Therefore, the applicant found that the mixtures of organic compounds “PC02”, “PC12” and “PC13” can also be effectively used in fuels, especially gasoline, and these mixtures are the same mixtures that gave the best results in previous lubricant friction tests (MTM, SRV).

[0569] Therefore, this last result, together with the results described above, allows the applicant to demonstrate how the mixture for the purpose of this invention can reduce friction when used in lubricants and fuels.

[0570] Importantly, the synthesis reported in Examples 1-8 was carried out using industrial-grade oleic acid, while the synthesis in Examples 9 and 10 used a mixture of commercial acids of plant (PC12) and animal (PC13) origin, with typical compositions as reported in the tables of the specification.

[0571] Example 55 (Comparative): Lubricant formulations containing essentially only amides and relative stability tests

[0572] To conduct this experimental test, an amide (AM-APD) sample of formula VI with a purity higher than 98% was prepared.

[0573] The procedure for obtaining it includes washing the PC02 sample with petroleum ether (Example 2).

[0574] This method allows the amide (insoluble in petroleum ether) to be separated from the other components of the mixture in Example 2.

[0575] As described in Examples 23-35, the product thus obtained is mixed with a master mixture (MM) to obtain a formulation referred to herein as MIX56 / 19.

[0576] The formulation containing only the amide of formula VI of Example 2 in MIX 56 / 19 was unstable, as precipitation was observed after less than a day, indicating that the amide had poor solubility in the lubricating composition, possibly due to its strong interaction with itself via hydrogen bonds.

[0577] Comparing Comparative Example 55 with the embodiments of the present invention in Tables 5-7, it appears that the addition of oxazoline (V) and (IX) to ester compounds (IV), (VII), (VIII) and amides (III) and (VI) has an unexpected synergistic effect in reducing friction, because MIX 41 / 19 and MIX 45 / 19, which contain the largest amount of oxazoline (about 59-65%), exhibit lower friction-reducing properties compared to mixtures MIX 39 / 19, MIX 40 / 19, MIX 53 / 19 and MIX 55 / 19, which contain smaller amounts of oxazoline (about 25-31%).

[0578] Without being bound by any theory, it can be inferred that oxazoline itself does not have high friction-reducing properties.

[0579] Furthermore, as can be observed again from the comparison between Comparative Example 55 and the examples in Tables 5-7, the use of oxazoline at a concentration of more than 7% by weight relative to the total weight of the mixture imparts a considerable improvement in the stability of the composition due to the improved solubility of the additive in the lubricating composition.

Claims

1. A friction-reducing additive suitable for use in lubricating oils and fuels including "low saps" and "medium saps". The additive is free of metals, sulfur, and phosphorus and is in the form of a mixture of organic compounds, the mixture comprising: -Amide, and / or -Carboxylic acid esters or mixtures of carboxylic acid esters, and -Oxazoline, in an amount of 20% to 70% relative to the total weight of the mixture. in Amides have the general formula (III), (III) Esters have the general formula (IV) (IV) Furthermore, oxazoline has the general formula (V) (V) Where R is a group selected from the group consisting of straight-chain or branched alkyl groups or straight-chain or branched alkenyl groups having 2 to 40 carbon atoms; R1 and R2 groups, which may be the same as or different from each other, are independently selected from the group consisting of: hydrogen, hydroxymethylene (-CH2OH), and straight-chain or branched hydrocarbon groups based on carbon and hydrogen having the following formula: C n H 2n+1 C n H 2n C n H n , where "n" is an integer ranging from 1 to 40.

2. The friction-reducing additive according to claim 1, wherein R is a group selected from the group consisting of straight-chain or branched alkyl groups or straight-chain or branched alkenyl groups having 2 to 28 carbon atoms.

3. The friction-reducing additive according to claim 1, wherein R is a group selected from the group consisting of straight-chain or branched alkyl groups or straight-chain or branched alkenyl groups having 2 to 20 carbon atoms.

4. The friction-reducing additive according to claim 1, wherein "n" is an integer in the range of 8-12.

5. The friction-reducing additive according to claim 1, wherein it is a fatty carboxylic acid of formula (I) or a mixture of a fatty carboxylic acid of formula (I) and fatty acids: (I) in -R is a group selected from the group consisting of straight-chain or branched alkyl groups or straight-chain or branched alkenyl groups having 2 to 40 carbon atoms; The product of the condensation reaction with the amino alcohol of formula (II) (II) The R1 and R2 groups are distinct from each other and are independently selected from the following groups: hydrogen, hydroxymethylene (-CH2OH), and straight-chain or branched hydrocarbon groups based on carbon and hydrogen with the following formula: C n H 2n+1 C n H 2n C n H n , where "n" is an integer ranging from 1 to 40, and if amino alcohol (II) is aminopropanediol, then R1=H and R2=-CH2OH.

6. The friction-reducing additive according to claim 5, wherein R is a group selected from the group consisting of straight-chain or branched alkyl groups or straight-chain or branched alkenyl groups having 2 to 28 carbon atoms.

7. The friction-reducing additive according to claim 5, wherein R is a group selected from the group consisting of straight-chain or branched alkyl groups or straight-chain or branched alkenyl groups having 2 to 20 carbon atoms.

8. The friction-reducing additive according to claim 5, wherein "n" is an integer in the range of 8-12.

9. The friction-reducing additive according to claim 5, wherein the amino alcohol (II) is aminopropylene glycol, R1=H and R2=-CH2OH.

10. The friction-reducing additive according to claim 5 or 9, wherein the carboxylic acid (I) is saturated or unsaturated, and is of plant, animal, or synthetic origin.

11. The friction-reducing additive according to claim 10, wherein the carboxylic acid (I) is selected from the group consisting of: decanoic acid, lauric acid, myristic acid, stearic acid, isostearic acid, arachidic acid, behenic acid and lignotaric acid, myrceneic acid, myristoleic acid, palmitoleic acid, oleic acid, cod oleic acid, erucic acid, linoleic acid and linolenic acid or mixtures thereof.

12. The friction-reducing additive according to claim 5 or 9, wherein the carboxylic acid (I) is oleic acid of animal or plant origin, or a mixture of oleic acid and other carboxylic acids, and the composition of the carboxylic acid (I) is as follows: 。 13. The friction-reducing additive according to claim 1, wherein the mixture comprises the following organic compounds: Amides of formula (VI), (WE) and / or The first ester of formula (VII) (VII) and / or The second ester of formula (VIII) (VIII) and Oxazolin of formula (IX) (IX) Wherein R has the meaning defined in claim 1.

14. The friction-reducing additive according to claim 1, wherein the mixture comprises the following organic compounds: amide of formula (X) (X) and / or Ester of formula (XI) (XI) and Oxazolin of formula (XII) (XII) Wherein R has the meaning defined in claim 1.

15. The friction-reducing additive according to claim 1, wherein, by weight % relative to the total weight of the mixture, the mixture comprises -30% to 75% amide (III); and -5% to 20% of one or more esters (IV); and -20% to 50% of oxazoline (V).

16. A method for preparing a friction-reducing additive in the form of a mixture, said mixture comprising an amide (III), an ester or a mixture of esters (IV), and an oxazoline (V) as defined in any one of the preceding claims, said method comprising the following steps: (a) In the presence of a solvent immiscible with water, a condensation reaction is carried out between a fatty acid or mixture of fatty acids of formula (I) as defined in claim 5 and an amino alcohol of formula (II) as defined in claim 5 to form a mixture of products containing compounds of general formulas (III), (IV) and (V) as defined in any of the preceding claims. (b) Perform one or more separation steps on the mixture with the water, unreacted reagents, and organic solvents formed during the condensation reaction. The separation is carried out under conditions in which one or more of the compounds of general formulas (III), (IV) and (V) are not removed from the mixture.

17. The method of claim 16, wherein the temperature in step (a) is at least 100°C.

18. The method according to claim 16, wherein the temperature in step (a) is 100°C-110°C to 220°C.

19. The method according to claim 16, wherein the temperature in step (a) is 150°C-160°C to 200°C.

20. The method according to claim 16 or 17, wherein the amount of amino alcohol used is expressed as a ratio between amino alcohol equivalents and carboxylic acid equivalents, and is 1 to 2.

21. The method of claim 20, wherein the amount of amino alcohol used is expressed as a ratio between amino alcohol equivalents and carboxylic acid equivalents, and is from 1.05 to 1.

4.

22. The method of claim 21, wherein the amount of amino alcohol used is expressed as a ratio between amino alcohol equivalents and carboxylic acid equivalents, and is from 1.1 to 1.

35.

23. The method according to claim 16 or 17, wherein the solvent in step (a) that is immiscible with the reaction water is selected from... -Aromatic hydrocarbons with 6 to 16 carbon atoms; - Aliphatic or alicyclic hydrocarbons with 7 to 16 carbon atoms; -Alkyl, aryl-alkyl and aryl ethers having 8 to 16 carbon atoms; -A mixture of its components.

24. The method of claim 23, wherein the aromatic hydrocarbon is selected from toluene, xylene, tetrahydronaphthalene, or Solvesso™.

25. The method according to claim 23, wherein the aliphatic or alicyclic hydrocarbon is decane or decahydronaphthalene.

26. The method of claim 23, wherein the alkyl, aryl-alkyl, and aryl ether are anisole, phenethyl ether, and diphenyl ether.

27. The method according to claim 23, wherein the solvent immiscible with the reaction water in step (a) is anisole, phenethyl ether or diphenyl ether, xylene, n-decane, Solvesso™ or a mixture thereof.

28. A lubricating composition comprising... -A mixture of compounds as defined in any of the preceding claims; - Lubricating base oil or a mixture of lubricating base oils.

29. The lubricating composition of claim 28, wherein the lubricating composition is a lubricant for automobiles with high fuel economy, a lubricant highly compatible with motor vehicle exhaust aftertreatment devices for reducing pollutant emissions, and a lubricant for Otto cycle internal combustion engines.

30. The lubricating composition according to claim 28, wherein the mixture of said compounds is a mixture of compounds of general formulas (III), (IV) and (V).

31. The lubricating composition according to claim 28, wherein the lubricating base oil or mixture of lubricating base oils is selected from mineral, synthetic, plant, animal-derived base oils and mixtures thereof.

32. The lubricating composition of claim 28, wherein the mixture of said compounds is present at a total concentration of 0.1 to 50% by weight relative to the weight of said lubricating composition.

33. The lubricating composition of claim 28, wherein the mixture of said compounds is present at a total concentration of 0.3 to 20% by weight relative to the weight of said lubricating composition.

34. The lubricating composition of claim 28, wherein the mixture of said compounds is present at a total concentration of 0.5 to 5% by weight relative to the weight of said lubricating composition.

35. A fuel composition comprising a mixture of organic compounds as defined in any one of the preceding claims.

36. The fuel composition of claim 35, wherein the fuel composition is a gasoline composition.

37. The fuel composition of claim 35, wherein the mixture of said organic compounds is in the form of a mixture dissolved in a solvent.

38. The fuel composition according to claim 37, wherein the additive solution is present in the fuel composition at a concentration of 1 to 10,000 ppm relative to the total weight of the composition.

39. The fuel composition according to claim 38, wherein the additive solution is present in the fuel composition at a concentration of 10 to 1000 ppm relative to the total weight of the composition.

40. The fuel composition of claim 39, wherein the additive solution is present in the fuel composition at a concentration of 50 to 800 ppm relative to the total weight of the composition.

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