Ether carboxylic acid composition

Abstract

The present invention relates to a composition comprising at least an ether carboxylic acid. The present invention also relates to a process for obtaining said composition and to the use of said composition in industrial applications such as engine oil compositions, metalworking compositions, lubricant compositions and oil fuel compositions.

Description

Technical Field

[0001] The present invention relates to a composition comprising at least an ether carboxylic acid. The present invention also relates to a process for obtaining said composition and to the use of said composition in industrial applications such as engine oil compositions, metalworking compositions, lubricant compositions and oil fuel compositions. Background Art

[0002] Ether carboxylic acids are organic carboxylic acids which, in addition to the carboxyl group, also have one or more ether bridges. Ether carboxylic acids or their alkali metal or amine salts are known to be mild detergents with a high lime soap dispersibility. They are used as multifunctional tools in formulations, for example as cleaning agents, emulsifiers, dispersants, solubilizers or hydrotropes. Therefore, they are used in laundry detergents and cosmetic formulations, and also for industrial applications.

[0003] The relevant properties of ether carboxylic acids and the methods of obtaining them make it easy for the user to manage the residual salt content, water content, selectivity and degree of carboxymethylation, as well as to obtain the products at lower raw material costs and using more environmentally friendly processes.

[0004] Ether carboxylic acids are used in different applications due to their associated properties. For example, they are used in cosmetic applications due to their mildness, easy application, good detergency and cleaning power, fluidity, being uniform at room temperature and exhibiting good foaming properties. Ether carboxylic acids are also of particular interest in industrial applications, such as in metalworking fluids, engine oils, oilfield applications, drilling fluids or lubricant applications due to their following properties: good solubility behavior, viscosity, thermal stability, hygroscopicity, foam control ability, lime soap dispersion, electrolyte stability, hydrotropy, good emulsifier, water hardness stability, improved lubricity and corrosion inhibition.

[0005] There are known processes for the preparation of ether carboxylic acids. The two main preparation processes are: the Williamson ether synthesis or carboxyalkylation, which consists in alkylating alcohols or fatty alcohol alkoxylates with chloroacetic acid derivatives; and a second preparation process which consists in oxidizing the same starting materials with various agents (atmospheric oxygen, hypochlorites, chlorites) under the catalysis of various catalysts.

[0006] The Williamson ether synthesis is the most common process for obtaining ether carboxylic acids. It can be carried out as a solid / solid process, ie, where the starting materials (chloroacetic acid and alkaline source) are in solid form.

[0007] EP1574560 describes a process for the preparation of ether carboxylic acid compounds, wherein the process comprises the steps of alkylating an oxoalkylated alcohol with sodium chloroacetate and sodium hydroxide in the solid state, then converting the obtained ether carboxylate into the free ether carboxylic acid by adding an acid, then liberating water from the obtained ether carboxylic acid by distillation under reduced pressure without washing, and finally removing the precipitated metal salt by filtration, obtaining a product with low residual water content and residual salt content values.

[0008] Williamson ether synthesis can also be carried out as a liquid / liquid process, in which the starting materials (chloroacetic acid and alkali source) are in liquid form. US4625057 describes a process for obtaining ether carboxylic acids, which comprises the reaction of an ether alcohol with a stoichiometric amount of free chlorocarboxylic acid and an aqueous solution of twice the stoichiometric amount of an aqueous base. The water content is maintained at 0.3-1.5% by weight, and the process results in an improved selectivity.

[0009] In addition, US3992443 describes a hybrid process in which an alcohol, preferably an ethoxylated alcohol, is carboxymethylated by reacting a mixture of an ethoxylated alcohol and a salt of chloroacetic acid with an alkaline hydroxide, the alkaline hydroxide being used both in solid form and in aqueous solution. An equimolar mixture of the starting alcohol and the chloroacetate is usually employed; however, depending on the intended effect, a molar excess of alcohol or a molar excess of chloroacetate may be used.

[0010] However, there is still a need for ether carboxylic acids which meet the requirements of industrial applications, in particular water hardness stability and improved lubricity.

[0011] The present invention provides a composition comprising at least ether carboxylic acid, a method for preparing the ether carboxylic acid and use thereof in engine oil applications, metal processing applications, lubricant applications and oil fuel applications, wherein the composition comprising the ether carboxylic acid meets the requirements of water hardness stability and improved lubricity. Summary of the invention

[0012] A first object of the present invention is a composition comprising an ether carboxylic acid.

[0013] Another object of the invention is a process for obtaining said composition.

[0014] Another object of the present invention is the use of said composition in industrial applications such as engine oils, metalworking compositions, lubricant compositions and oil fuel compositions.

[0015] Another object of the invention is a process for obtaining engine oil compositions, metalworking compositions, lubricant compositions and oil fuel compositions, based on the application of the composition according to the invention to these compositions. DETAILED DESCRIPTION

[0016] The main object of the present invention is a composition comprising an ether carboxylic acid of formula (I).

[0017] Ether carboxylic acid:

[0018] Ether carboxylic acid is represented by formula (I):

[0019] Formula (I)

[0020] R1-OP-CH2-COOX

[0021] wherein R1 is a straight or branched alkyl or alkenyl chain having 1 to 30 carbon atoms, preferably 3 to 24 carbon atoms, more preferably 6 to 22 carbon atoms; P comprises an average of n -(CH2CH2O)- units and / or an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units and / or an average of q -(CH2CHR3O)- or -(CHR3CH2O)- units, wherein n represents a value in the range of 0 to 50, m represents a value in the range of 0 to 50, and q represents a value in the range of 0 to 50; and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 100; R2 represents a -CH3 group, and R3 represents a -CH2CH3 group; and X represents a hydrogen atom, or a cation selected from the group consisting of an alkali metal, an alkaline earth metal, ammonium, an alkylammonium, an alkanolammonium or glucammonium.

[0022] The ether carboxylic acids of formula (I) are usually mixtures of compounds which satisfy formula (I) but have different meanings of R1, m, n and q. The ranges specified above and below for m, n and q define the average values ​​of the units in this mixture.

[0023] In one embodiment of the present invention, P comprises an average of n -(CH2CH2O)- units and / or an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units and / or an average of q -(CH2CHR3O)- or -(CHR3CH2O)- units, wherein n represents a value in the range of 0 to 50, preferably in the range of 0 to 30, more preferably in the range of 0 to 25, even more preferably in the range of 0 to 20; m represents a value in the range of 0 to 50, preferably in the range of 0 to 30, more preferably in the range of 0 to 25, even more preferably in the range of 0 to 20; q represents a value in the range of 0 to 50, preferably in the range of 0 to 30, more preferably in the range of 0 to 25, even more preferably in the range of 0 to 20; and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 100, preferably from 1 to 50, more preferably from 1 to 30, even more preferably from 1 to 25.

[0024] In one embodiment of the present invention, the ether carboxylic acids of formula (I) may be ethoxylated and / or propoxylated and / or butoxylated. Both ether carboxylic acids according to formula (I) comprising ethylene and / or propylene oxide and / or butylene oxide groups in individual blocks and ether carboxylic acids according to formula (I) comprising randomly distributed ethylene oxide and / or propylene oxide and / or butylene oxide groups can be used in the composition according to the present invention.

[0025] In one embodiment of the present invention, P comprises an average of n -(CH2CH2O)- units, wherein n represents a value in the range of 0 to 50, preferably in the range of 1 to 30, more preferably in the range of 1 to 25, even more preferably in the range of 1 to 20; and m and q represent 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 50, preferably 1 to 30, more preferably 1 to 25, even more preferably 1 to 20.

[0026] In another embodiment of the present invention, P comprises an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units, wherein m represents a value in the range of 0 to 50, preferably in the range of 1 to 30, more preferably in the range of 1 to 25, even more preferably in the range of 1 to 20; and n and q represent 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 50, preferably 1 to 30, more preferably 1 to 25, even more preferably 1 to 20.

[0027] In another embodiment of the present invention, P comprises an average of q -(CH2CHR3O)- or -(CHR3CH2O)- units, wherein q represents a value in the range of 0 to 50, preferably in the range of 1 to 30, more preferably in the range of 1 to 25, even more preferably in the range of 1 to 20; and n and m represent 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 50, preferably 1 to 30, more preferably 1 to 25, even more preferably 1 to 20.

[0028] In another embodiment of the present invention, P comprises an average of n -(CH2CH2O)- units and an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units, wherein n represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; m represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; q represents 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 100, preferably from 1 to 50, more preferably from 1 to 35, even more preferably from 1 to 25.

[0029] In one embodiment of the present invention, the ether carboxylic acid of formula (I) comprises ethylene oxide and propylene oxide groups. Ether carboxylic acid compounds of formula (I) comprising ethylene oxide and propylene oxide groups in separate blocks and ether carboxylic acid compounds of formula (I) comprising randomly distributed ethylene oxide and propylene oxide groups can be used in the composition according to the present invention.

[0030] In a preferred embodiment of the present invention, the ether carboxylic acids of formula (I) comprise ethylene oxide and propylene oxide groups.Ether carboxylic acids of formula (I) comprising ethylene oxide and propylene oxide in separate blocks can be used in the composition according to the present invention.

[0031] In another preferred embodiment of the present invention, the ether carboxylic acid of formula (I) comprises ethylene oxide and propylene oxide groups. The ether carboxylic acid of formula (I) comprises ethylene oxide and propylene oxide groups in different groups, wherein the ethylene oxide group is closer to the carboxyl group. The preferred compound of this embodiment is a compound of formula (Ia):

[0032] Formula (Ia)

[0033] R1-O-(CH2CHR2O)m1-(CHR2CH2O)m2-(CH2CH2O)n-CH2-COOX

[0034] wherein R1, R2, X and n have the same meanings as in formula (I), and wherein m1 and m2 each represent a value within the range of 0 to 50, wherein m1+m2 is a value within the range of 0 to 50.

[0035] In another embodiment of the present invention, P comprises an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units and an average of q -(CH2CHR3O)- or -(CHR3CH2O)- units, wherein m represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; q represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; n represents 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 100, preferably 1 to 50, more preferably 1 to 35, even more preferably 1 to 25.

[0036] In another embodiment of the present invention, P comprises an average of n -(CH2CH2O)- units and an average of q -(CH2CHR3O)- or -(CHR3CH2O)- units, wherein n represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; q represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; m represents 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 100, preferably from 1 to 50, more preferably from 1 to 35, even more preferably from 1 to 25.

[0037] In another embodiment of the present invention, R1 is a straight chain or branched alkyl group containing 1 to 30 carbon atoms or a straight chain alkenyl group containing 1 to 30 carbon atoms and 1 to 3 double bonds; preferably, the alkyl or alkenyl group contains 4 to 28 carbon atoms, more preferably 6 to 18 carbon atoms.

[0038] In another embodiment of the present invention, R1 is a straight or branched alkyl or straight alkenyl group derived from natural fats and oils and synthetic sources. Preferred fats and oils include palm oil, coconut oil, sunflower oil, rapeseed oil, castor oil, olive oil, soybean oil; animal fats, such as tallow, bone oil, fish oil, their hardened oils and semi-hardened oils, and mixtures thereof. Due to their natural origin, fats and oils may contain a wide variety of alkyl and / or alkenyl groups, which are straight or branched, saturated or unsaturated.

[0039] In another embodiment of the present invention, the ether carboxylic acid of formula (I) is derived from C1-C 30 Fatty alcohol, preferably C4-C 28 Fatty alcohols, preferably derived from natural fats and oils as well as synthetic sources. Preferred fats and oils include palm oil, coconut oil, sunflower oil, rapeseed oil, castor oil, olive oil, soybean oil; animal fats, such as tallow, bone oil, fish oil, hardened oils and semi-hardened oils thereof; and mixtures thereof. Due to their natural origin, fatty alcohols may contain a wide variety of alkyl and / or alkenyl groups, which are linear or branched, saturated or unsaturated.

[0040] In a particularly preferred embodiment, the ether carboxylic acid of the formula (I) is an ether carboxylic acid in which n represents a value in the range from 0 to 10, m represents a value in the range from 0 to 8, q represents 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 2 to 12.

[0041] In another preferred embodiment, the ether carboxylic acid compound of formula (I) is an ether carboxylic acid compound wherein m represents a value in the range of 0 to 10, preferably 1 to 8, more preferably 1 to 5, n and q represent 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 10, preferably 1 to 8, more preferably 1 to 5.

[0042] Preparation method

[0043] The ether carboxylic acid of formula (I) according to the present invention can be prepared by a process comprising at least the steps of alkoxylating a fatty alcohol to obtain a mixture containing alkoxylated fatty alcohols, and alkylating the mixture with a halogenated carboxylic acid.

[0044] i. Alkoxylation of fatty alcohols

[0045] The alkoxylation of alcohols can be carried out under standard conditions known to those skilled in the art. For example, polyalkoxylated groups are obtained by adding ethylene oxide and / or propylene oxide and / or butylene oxide to fatty alcohols, mostly using basic catalysts such as NaOH, KOH, Na2CO3, K2CO3, KOCH3 and solutions thereof in methanol, or NaOCH3 and solutions thereof in methanol, to provide a broad polyalkoxylated oxide distribution (broad degree of alkoxylation). For special applications, the alkoxylation can be catalyzed by Lewis acids or by using metallic Na or NaH to achieve a narrow range distribution (narrow degree of alkoxylation). Suitable examples of usable alkoxylated alcohols are ROX RLM 80V(Laureth-8), ROX RLM 22 (Laureth-2), ROX RS-0602N (alkoxylated stearyl alcohol), ROXRC-0960N (alkoxylated cetyl alcohol), both sold by Kao Chemicals Europe.

[0046] The products obtained from the alkoxylation reaction comprise a mixture of alkoxylated fatty alcohols (ethoxylated and / or propoxylated and / or butoxylated) and non-alkoxylated fatty alcohols.

[0047] In one embodiment of the present invention, the order of addition of ethylene oxide and / or propylene oxide and / or butylene oxide to the fatty alcohol is random.

[0048] In another embodiment of the present invention, the propylene oxide and / or butylene oxide groups are added first and then the ethylene oxide groups are added.

[0049] In one embodiment of the present invention, the alkoxylated fatty alcohol is represented by formula (II):

[0050] Formula (II)

[0051] R1-OPH

[0052] wherein R1 is a straight or branched alkyl or alkenyl chain having 1 to 30 carbon atoms, preferably 3 to 24 carbon atoms, more preferably 6 to 22 carbon atoms; P comprises an average of n -(CH2CH2O)- units and / or an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units and / or an average of q -(CH2CHR3O)- or -(CHR3CH2O)- units; wherein n represents a value in the range of 0 to 50, m represents a value in the range of 0 to 50, and q represents a value in the range of 0 to 50; and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 60; R2 represents a -CH3 group, and R3 represents a -CH2CH3 group.

[0053] Suitable fatty alcohols according to formula (II) are n-butanol, n-hexanol, n-octanol, 2-ethylbutanol, 2-methylpentanol, 2-ethylhexanol, 2-methylheptanol, n-decanol, 2-methyl-4-nonanol, 3,7-dimethyl-3-octanol, 3,7-dimethyl-1-octanol, 3,6-dimethyl-3-octanol, lauryl alcohol (1-dodecanol), myristyl alcohol (1-tetradecanol), cetyl alcohol (1-hexadecanol), palmitoleyl alcohol (cis-9-hexadecane-1-ol), stearyl alcohol (1-octadecane-1-ol), isostearyl alcohol (16-methylheptadecan-1-ol), oleyl alcohol (cis-9-octadecene-1-ol), isostearyl alcohol (1-octadecene-1-ol), cis-9-octadecene-1-ol, ... 1-ol), linoleyl alcohol (9Z, 12Z-octadecadien-1-ol), octadecadien-1-ol), linoleyl alcohol (9Z, 12Z-octadecadien-1-ol), octadecadien-1-ol), linoleyl alcohol (9E, 12E-octadecadien-1-ol), linoleyl alcohol (9Z, 12Z, 15Z-octadecatriene-1-ol), octadecatrien-1-ol (9E, 12E, 15-E-octadecatriene-1-ol), ricinoleyl alcohol (12-hydroxy-9-octadecene-1-ol), arachidyl alcohol (1-eicosanol), behenyl alcohol (1-docosanol), erucyl alcohol (cis-13-eicosan-1-ol) or mixtures thereof; and their corresponding alkoxylated (ethoxylated and / or propoxylated and / or butoxylated) alcohols or mixtures thereof.

[0054] In one embodiment of the present invention, the fatty alcohol is cetyl alcohol, stearyl alcohol, oleyl alcohol or mixtures thereof, their corresponding alkoxylated (ethoxylated and / or propoxylated and / or butoxylated) alcohols or mixtures thereof.

[0055] In another embodiment of the present invention, the fatty alcohols are derived from natural fats and oils as well as synthetic sources. Preferred fats and oils include palm oil, coconut oil, sunflower oil, rapeseed oil, castor oil, olive oil, soybean oil; animal fats, such as tallow, bone oil, fish oil, their hardened oils and semi-hardened oils; and mixtures thereof. Due to their natural origin, fats and oils may contain a wide variety of alkyl and / or alkenyl groups, which are linear or branched, saturated or unsaturated.

[0056] In one embodiment of the present invention, the alkoxylated fatty alcohol compound of formula (II) may be ethoxylated and propoxylated. Fatty alcohol compounds comprising ethylene oxide and propylene oxide groups in separate blocks and fatty alcohols comprising randomly distributed ethylene oxide and propylene oxide groups may be used in the present invention.

[0057] In one embodiment of the present invention, the alkoxylated fatty alcohol compounds of formula (II) may be ethoxylated and propoxylated.Fatty alcohol compounds comprising ethylene oxide and propylene oxide in separate blocks may be used in the composition according to the present invention.

[0058] In another embodiment of the present invention, the alkoxylated fatty alcohol compound of formula (II) comprises ethylene oxide and propylene oxide groups in separate groups, wherein the ethylene oxide group is closer to the free hydroxyl group. The preferred compound of this embodiment is a compound of formula (IIa):

[0059] Formula (IIa)

[0060] R1-O-(CH2CHR2O)m1-(CHR2CH2O)m2-(CH2CH2O)nH

[0061] wherein R1, R2 and n have the same meanings as in formula (I), and wherein m1 and m2 each represent a value within the range of 0 to 50, wherein m1+m2 is a value within the range of 0 to 50.

[0062] ii. Carboxyalkylation reaction:

[0063] An alkoxylated (ethoxylated and / or propoxylated and / or butoxylated) fatty alcohol is reacted with a halogenated carboxylic acid, wherein there is an initial charge of an alkaline solution to the mixture before the halogenated carboxylic acid is added to the reaction, and wherein the initial charge of the alkaline solution comprises from 5% to 50% by weight of the total amount of the alkaline solution, preferably from 3% to 25% by weight of the total amount of the alkaline solution.

[0064] In the carboxyalkylation reaction, the molar ratio between the halogenated carboxylic acid and the alkali salt in the alkali solution is higher than 1:2.05 to 1:3, preferably 1:2.15 to 1:2.5.

[0065] In one embodiment of the present invention, the halocarboxylic acid is a C2 to C5 chlorocarboxylic acid. In a preferred embodiment of the present invention, the halocarboxylic acid is monochloroacetic acid.

[0066] In one embodiment of the present invention, the carboxyalkylation reaction is a carboxymethylation reaction.

[0067] In one embodiment of the present invention, the halocarboxylic acid is an aqueous solution of the halocarboxylic acid.

[0068] In another embodiment of the present invention, the concentration of the halogenated carboxylic acid in the aqueous solution is 60 wt % to 85 wt %. In another embodiment of the present invention, the concentration of the halogenated carboxylic acid in the aqueous solution is 70 wt % to 80 wt %.

[0069] In one embodiment of the present invention, the aqueous halogenated carboxylic acid is an aqueous C2 to C5 chlorocarboxylic acid. In a preferred embodiment of the present invention, the aqueous halogenated carboxylic acid is an aqueous monochloroacetic acid.

[0070] In one embodiment of the present invention, the alkaline solution is an aqueous alkaline solution.

[0071] In another embodiment of the present invention, the concentration of the alkaline solution is 30% to 60% by weight of the alkali metal hydroxide or alkaline earth metal hydroxide in the aqueous alkaline solution. In another embodiment of the present invention, the concentration of the alkaline solution is 40% to 55% by weight of the alkali metal hydroxide or alkaline earth metal hydroxide in the aqueous alkaline solution.

[0072] In another embodiment of the present invention, the alkaline solution is an alkali metal hydroxide or an alkaline earth metal hydroxide, such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, lithium hydroxide, barium hydroxide. In one embodiment of the present invention, the preferred alkaline solution is sodium hydroxide and potassium hydroxide.

[0073] In a preferred embodiment of the present invention, all reagents in the carboxyalkylation reaction are in aqueous solution.

[0074] In one embodiment of the present invention, the feeding time of the initial charge of the alkaline solution accounts for 1% to 50% of the total time of the carboxyalkylation reaction, preferably 5% to 25% of the total time of the carboxyalkylation reaction.

[0075] In one embodiment of the present invention, the alkoxylated (ethoxylated and / or propoxylated and / or butoxylated) alcohol to be reacted with the halocarboxylic acid is prepared in situ prior to the carboxyalkylation reaction.

[0076] In another embodiment of the present invention, the alkoxylated (ethoxylated and / or propoxylated and / or butoxylated) alcohol reacted with the halocarboxylic acid is commercially available.

[0077] According to the present invention, the aqueous base solution and the halocarboxylic acid are preferably fed continuously to the reaction.

[0078] The continuous feed of the alkaline solution begins before the feed of the halocarboxylic acid but continues during the feed of the halocarboxylic acid.

[0079] In one embodiment of the present invention, the process comprises the step iii) of converting the alkali metal ether carboxylate into the free ether carboxylic acid by acidification with any acid, preferably HCl, after the carboxyalkylation reaction.

[0080] The composition obtained from the carboxyalkylation reaction comprises ether carboxylic acids, unreacted materials in the process for obtaining the ether carboxylic acids (such as alkoxylated fatty alcohols that have not been carboxyalkylated), free fatty alcohols, esters or by-products from the same reaction (such as sodium glycolate, sodium diglycolate), materials with low vapor pressure, high boiling point materials, oligomers and polymers, and inorganic halides (such as sodium chloride) and water.

[0081] In one embodiment of the present invention, the method further comprises: step iv) comprising a washing step.

[0082] In one embodiment of the present invention, the method further comprises: step v) comprising a distillation step.

[0083] In another embodiment of the present invention, the degree of conversion of the ether carboxylic acid is higher than 40%, preferably higher than 60%, more preferably higher than 70%, even more preferably higher than 80%.

[0084] The degree of conversion is calculated as the number of moles of ether carboxylic acid obtained divided by the number of moles of initial alkoxylated fatty alcohol used.

[0085] According to the described procedure, the amount of oxidizable species present in the reaction mixture can be quantified, i.e. the amount of oxygen that can be consumed by the reaction in the solution. This chemical oxygen demand (COD) can be expressed as the mass of oxygen consumed relative to the volume of the solution, which is expressed in SI units as milligrams O2 / liter (mg O2 / L).

[0086] In one embodiment of the present invention, the chemical oxygen demand of the solution is measured in the aqueous phase obtained after step iv) comprising a washing step.

[0087] In one embodiment of the present invention, the chemical oxygen demand of the solution after the process for obtaining ether carboxylic acid is below 45000 mg O2 / L, preferably below 40000 mg O2 / L.

[0088] In one embodiment of the present invention, the content of inorganic salts after the washing step is less than 1% by weight.

[0089] In one embodiment of the present invention, the water content in the organic phase after the washing stage is below 5% by weight.

[0090] The composition of the present invention:

[0091] The composition of the present invention contains the ether carboxylic acid of formula (I). This composition can be prepared by the above-mentioned method.

[0092] In another embodiment of the present invention, the composition comprises at least 40% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight of ether carboxylic acid of formula (I), relative to the total active materials of the composition of the present invention.

[0093] As active material it is to be understood a specific group of components which are responsible for a specific action; within the scope of the present application, active materials are all surfactants present in the composition.

[0094] In a preferred embodiment of the present invention, the composition comprises an ether carboxylic acid of formula (I), wherein P comprises n -(CH2CH2O)- units and n represents a value in the range of 0 to 50, preferably in the range of 1 to 30, more preferably in the range of 1 to 25, even more preferably in the range of 1 to 20; m and q represent 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 50, preferably 1 to 30, more preferably 1 to 25, even more preferably 1 to 20, and wherein the composition comprises at least 40% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight of ether carboxylic acid compounds of formula (I), relative to the total active materials of the composition of the present invention.

[0095] In another preferred embodiment of the present invention, the composition comprises an ether carboxylic acid of formula (I), wherein P comprises an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units, and m represents a value in the range of 0 to 50, preferably in the range of 1 to 30, more preferably in the range of 1 to 25, even more preferably in the range of 1 to 20; n and q represent 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 50, preferably 1 to 30, more preferably 1 to 25, even more preferably 1 to 20, and wherein the composition comprises at least 40% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight of ether carboxylic acid compounds of formula (I), relative to the total active materials of the composition of the present invention.

[0096] In another preferred embodiment of the present invention, the composition comprises an ether carboxylic acid of formula (I), wherein P comprises an average of n -(CH2CH2O)- units and an average of m -(CH2CHR2O)- or -(CHR2CH2O)- units, and n represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; and m represents a value in the range of 0 to 50, preferably in the range of 1 to 25, more preferably in the range of 1 to 20, even more preferably in the range of 1 to 15; q represents 0, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value of 1 to 100, preferably 1 to 50, more preferably 1 to 35, even more preferably 1 to 25, and wherein the composition comprises at least 40% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight of ether carboxylic acid compounds of formula (I), relative to the total active materials of the composition of the present invention.

[0097] The compositions of the present invention have good water hardness stability and improved lubricity.

[0098] Furthermore, the composition of the present invention also preferably meets the requirements of solubility, viscosity, thermal stability, hygroscopicity, foam control ability, lime soap dispersion, electrolyte stability, hydrotropy, good emulsifier and corrosion inhibition.

[0099] Use of the composition according to the invention in industrial applications:

[0100] The composition according to the invention may be used in industrial applications, such as in engine oils, lubricants, metalworking fluids or oilfield applications.

[0101] The use of compositions containing ether carboxylic acids in industrial applications can be explained by their foam control capabilities, lime soap dispersion, high thermal stability, electrolyte stability, hydrotropy, solubilizing properties, good emulsifier, water hardness stability, and improved lubricity and corrosion inhibition.

[0102] The composition according to the invention comprising the ether carboxylic acid of formula (I) can be used as an additive in formulations for industrial applications. That is, the composition according to the invention can be used as an additive in engine oil formulations, lubricant formulations, metalworking fluid formulations or oilfield formulations.

[0103] In one embodiment of the present invention, the composition comprising the ether carboxylic acid of formula (I) according to the present invention can be used as an additive in a preparation for industrial application, wherein the amount of the composition is 0.1% to 10% by weight, preferably 1% to 5% by weight, based on the total weight of the preparation for industrial application.

[0104] A further aspect of the invention is the use of a composition according to the invention in an engine oil.

[0105] Another aspect of the invention is the use of a composition according to the invention in a lubricant.

[0106] A further aspect of the invention is the use of a composition according to the invention in a metalworking fluid.

[0107] Another aspect of the invention is the use of a composition according to the invention in an oil field.

[0108] Another aspect of the present invention is a method for preparing an engine oil, the method comprising adding a composition according to the present invention to the engine oil.

[0109] Another aspect of the present invention is a method for preparing a lubricant, the method comprising adding the composition according to the present invention to the lubricant.

[0110] Another aspect of the present invention is a method for preparing a metalworking fluid, the method comprising adding a composition according to the present invention to the metalworking fluid.

[0111] Another aspect of the invention is a method of preparing an oilfield composition, the method comprising adding a composition according to the invention to an oilfield composition.

[0112] In order to provide those skilled in the art with a sufficiently clear and complete description of the present invention, the following examples are given, but should not be considered to limit the basic aspects of its subject matter, as set forth in the previous part of this specification.

[0113] Example:

[0114] The first part of the Examples section deals with the preparation of the compositions of the invention.

[0115] The second part of the Examples section deals with the performance of the compositions of the invention in industrial applications.

[0116] 1. Preparation of a composition comprising an ether carboxylic acid compound according to the present invention.

[0117] Example 1 (Comparative Example C1):

[0118] 692 grams (1 mol) of cetyl / stearyl fatty alcohol alkoxylated with 6 propoxylated units and 2 ethoxylated units were introduced into a double-walled reactor. The reactor was heated to 105° C. and the pressure was set to 20 mbar. The mixture was stirred (600 rpm) and 126 grams (1 mol) of an aqueous solution (75%) of monochloroacetic acid (MCA) and 160 grams (2 mol) of an aqueous solution (50%) of sodium hydroxide (NaOH) were separately and simultaneously introduced into the reactor. Monochloroacetic acid was introduced into the reactor at a feed rate of 30 mmol / min, and sodium hydroxide was introduced into the reactor at a feed rate of 60 mmol / min. Water was removed and collected in a downstream cooling trap. After a reaction time of 33 minutes, an aging step of 30 minutes was performed. Then, warm hydrochloric acid (30%) was added to the reaction mixture until a pH below 3 was obtained. The reaction mixture was transferred to a heated separation container and additional water was added to reach a NaCl concentration of approximately 20% in the water layer. The phase separation was carried out without stirring at a temperature of 100-105° C. After separation of the lower aqueous phase, 702 g of a pale yellow liquid were obtained.

[0119] Embodiment 2 (comparative example C2):

[0120] 692 grams (1 mol) of cetyl / stearyl fatty alcohol alkoxylated with 6 propoxylated units and 2 ethoxylated units were introduced into a double-walled reactor. The reactor was heated to 105° C. and the pressure was set to 20 mbar. The mixture was stirred (600 rpm) and 126 g (1 mol) of an aqueous solution (75%) of monochloroacetic acid (MCA) and 160 g (2 mol) of an aqueous solution (50%) of sodium hydroxide were introduced into the reactor separately. Monochloroacetic acid was introduced into the reactor at a feed rate of 30 mmol / min, and sodium hydroxide was introduced into the reactor at a feed rate of 60 mmol / min. The addition of NaOH was started earlier (3.3 minutes before the start of the addition of monochloroacetic acid), and a total of 10% by weight of NaOH was fed into the reactor during the early feeding step. Water was removed and collected in a downstream cooling trap. After a reaction time of 33 minutes, an aging step of 30 minutes was performed. Then, warm hydrochloric acid (30%) was added to the reaction mixture until a pH below 3 was obtained. The reaction mixture was transferred to a heated separation vessel and additional water was added to reach a NaCl concentration of about 20% in the aqueous layer. The phase separation was carried out without stirring at a temperature of 100 to 105° C. After separation of the lower aqueous phase, the product was obtained as 712 g of a light yellow liquid.

[0121] Example 3 (Comparative Example C3):

[0122] 692 grams (1 mol) of cetyl / stearyl fatty alcohol alkoxylated with 6 propoxylated units and 2 ethoxylated units are introduced into a double-walled reactor. The reactor is heated to 105° C. and the pressure is set to 20 mbar. The mixture is stirred (600 rpm) and 126 g (1 mol) of an aqueous solution (75%) of monochloroacetic acid (MCA) and 169 g (2,1 mol) of an aqueous solution (50%) of sodium hydroxide are introduced separately and simultaneously into the reactor. Monochloroacetic acid is introduced into the reactor at a feed rate of 30 mmol / min, and sodium hydroxide is introduced into the reactor at a feed rate of 63 mmol / min. Water is removed and collected in a downstream cooling trap. After a reaction time of 33 minutes, an aging step of 30 minutes is performed. Then, warm hydrochloric acid (30%) is added to the reaction mixture until a pH below 3 is obtained. The reaction mixture is transferred to a heated separation container and additional water is added to reach a NaCl concentration of approximately 20% in the water layer. The phase separation was carried out without stirring at a temperature of 100 to 105° C. After separation of the lower aqueous phase, the product was obtained as 709 g of a light yellow liquid.

[0123] Embodiment 4 (comparative example C4):

[0124] 692 grams (1 mol) of cetyl / stearyl fatty alcohol alkoxylated with 6 propoxylated units and 2 ethoxylated units were introduced into a double-walled reactor. The reactor was heated to 105° C. and the pressure was set to 20 mbar. The mixture was stirred (600 rpm) and 126 g (1 mol) of an aqueous solution (75%) of monochloroacetic acid (MCA) and 167 g (2.075 mol) of an aqueous solution (50%) of sodium hydroxide were introduced into the reactor separately. Monochloroacetic acid was introduced into the reactor at a feed rate of 30 mmol / min and sodium hydroxide was introduced into the reactor at a feed rate of 62,3 mmol / min. The addition of NaOH was started earlier (5 minutes before the start of the addition of monochloroacetic acid) and a total of 15% by weight of NaOH was fed into the reactor during the early feeding step. Water was removed and collected in a downstream cooling trap. After 33 minutes of reaction time, an aging step of 30 minutes was carried out. Then, warm hydrochloric acid (30%) was added to the reaction mixture until a pH below 3 was obtained. The reaction mixture was transferred to a heated separation vessel and additional water was added to reach a NaCl concentration of about 20% in the aqueous layer. The phase separation was carried out without stirring at a temperature of 100 to 105° C. After separation of the lower aqueous phase, the product was obtained as 729 g of a light yellow liquid.

[0125] Embodiment 5 (comparative example 5):

[0126] The procedure of Example 3 (Comparative 3) was repeated using cetyl / stearyl fatty alcohol alkoxylated with 9 ethoxylation units as starting material for the synthesis.

[0127] Embodiment 6 (comparative example 6):

[0128] The procedure of Example 4 (Comparative 4) was repeated using cetyl / stearyl fatty alcohol alkoxylated with 9 ethoxylation units as starting material for the synthesis.

[0129] Example 7 (according to the present invention A):

[0130] 692 grams (1 mol) of cetyl / stearyl fatty alcohol alkoxylated with 6 propoxylated units and 2 ethoxylated units were introduced into a double-walled reactor. The reactor was heated to 105° C. and the pressure was set to 20 mbar. The mixture was stirred (600 rpm) and 126 g (1 mol) of an aqueous solution (75%) of monochloroacetic acid (MCA) and 173 g (2.15 mol) of an aqueous solution (50%) of sodium hydroxide were introduced into the reactor separately. Monochloroacetic acid was introduced into the reactor at a feed rate of 30 mmol / min and sodium hydroxide was introduced into the reactor at a feed rate of 64,5 mmol / min. The addition of NaOH was started earlier (5 minutes before the start of the addition of monochloroacetic acid) and a total of 15% by weight of NaOH was fed into the reactor during the early feeding step. Water was removed and collected in a downstream cooling trap. After a reaction time of 33 minutes, an aging step of 30 minutes was carried out. Then, warm hydrochloric acid (30%) was added to the reaction mixture until a pH below 3 was obtained. The reaction mixture was then transferred to a heated separation vessel and additional water was added to reach a NaCl concentration of about 20% in the aqueous layer. The phase separation was carried out at a temperature of 100 to 105° C. without stirring. After separation of the lower aqueous phase, the product was obtained as 720 g of a light yellow liquid.

[0131] Example 8 (according to the present invention B):

[0132] 692 grams (1 mol) of cetyl / stearyl fatty alcohol alkoxylated with 6 propoxylated units and 2 ethoxylated units were introduced into a double-walled reactor. The reactor was heated to 105° C. and the pressure was set to 20 mbar. The mixture was stirred (600 rpm) and 126 g (1 mol) of an aqueous solution (75%) of monochloroacetic acid (MCA) and 179 g (2.225 mol) of an aqueous solution (50%) of sodium hydroxide were introduced separately into the reactor. Monochloroacetic acid was introduced into the reactor at a feed rate of 30 mmol / min and sodium hydroxide was introduced into the reactor at a feed rate of 66,8 mmol / min. The addition of NaOH was started earlier (5 minutes before the start of the addition of monochloroacetic acid) and a total of 15% by weight of NaOH was fed into the reactor during the early feeding step. Water was removed and collected in a downstream cooling trap. After a reaction time of 33 minutes, an aging step of 30 minutes was carried out. Then, warm hydrochloric acid (30%) was added to the reaction mixture until a pH below 3 was obtained. The reaction mixture was then transferred to a heated separation vessel and additional water was added to reach a NaCl concentration of about 20% in the aqueous layer. The phase separation was carried out at a temperature of 100 to 105° C. without stirring. After separation of the lower aqueous phase, the product was obtained as 720 g of a light yellow liquid.

[0133] Example 9 (according to the present invention C):

[0134] The procedure of Example 7 (Invention A) was repeated using cetyl / stearyl fatty alcohol alkoxylated with 9 ethoxylation units as starting material for the synthesis.

[0135] Example 10 (according to the present invention D):

[0136] The procedure of Example 8 (Invention B) was repeated using cetyl / stearyl fatty alcohol alkoxylated with 9 ethoxylation units as starting material for the synthesis.

[0137] Table 1 summarizes all prepared compositions (molar ratio NaOH:MCA, initial charge of NaOH) as well as the degree of conversion.

[0138] Table 1:

[0139]

[0140] Table 2 summarizes the chemical oxygen demand (COD) of Examples C1 to C4, A and B:

[0141] Table 2

[0142]

[0143] The oxygen demand is determined according to standard DIN 38409-H41 and is measured in the aqueous phase after the washing step.

[0144] 2. Performance of the composition of the present invention in industrial applications:

[0145] Relevant properties for industrial applications are lubricity and water hardness stability.

[0146] The lubricity of the compositions prepared in Examples 1 to 6 can be measured using a Microtap TTT Tapping-Torque-Testsystem. The detailed parameters of the TTT test apparatus are listed in Table 3.

[0147] Table 3:

[0148] Depth [mm] 8000 Speed ​​[1 / min.] 800 Torque [Ncm] 400 Thread Right Return rate (%) 100 Starting conditions Manual First slice pressure Fz 5 Lubrication tact none relaxation 0

[0149] For the torque test, 10 w / w% of the composition of the example was diluted in Marcol 52 (Exxon Mobil white oil). In addition, a blank containing only oil was measured. The instrument used for the TTT test was:

[0150] Test rod: AlZnMgCu01, 5 / 3.4365 / 7075

[0151] Tool: TTT_M4F-NT HSSE

[0152] Table 4 summarizes the results obtained for the compositions of Examples C1 to C4, A and B:

[0153] Table 4:

[0154] Average torque [Ncm] Marcol 52 94.3 C1 97.0 C2 95.0 C3 94.6 C4 93.3 A 91.2 B 92.4

[0155] From these results it can be seen that the composition according to the present invention shows lower results in terms of torque and therefore shows better results in terms of lubricity compared to the blank or comparative example.

[0156] Another relevant property for industrial applications is water hardness stability. Table 5 shows the water hardness stability of the compositions of Examples C5, C6, C and D.

[0157] Table 5:

[0158] Example Water hardness stability [%] C5 57,1 C6 72,9 C 95,3 D 97,1

[0159] DIN 51367 / 51368 was used to determine the water hardness stability.

[0160] From these results it can be seen that the composition according to the present invention shows better water hardness stability.

Claims

1. A method for preparing a composition, the method comprising the following steps: i. providing an oxyalkylated alcohol compound of formula (II) in a reactor, Formula (II) R1-OPH wherein R1 is a straight or branched alkyl or alkenyl chain having 1 to 30 carbon atoms; P comprises an average of n –(CH2CH2O)- units and / or an average of m –(CH2CHR2O)- or –(CHR2CH2O)- units and / or an average of q –(CH2CHR3O)- or –(CHR3CH2O)- units; wherein n represents a value in the range of 0 to 50, m represents a value in the range of 0 to 50, and q represents a value in the range of 0 to 50, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 60; R2 represents a –CH3 group, and R3 represents a –CH2CH3 group; ii. feeding the base solution into the oxyalkylated alcohol compound of formula (II); as well as iii. carboxylating the oxyalkylated alcohol compound of formula (II) with a C2 to C5 chlorocarboxylic acid, wherein the molar ratio between the C2 to C5 chlorocarboxylic acid and the alkali salt in the alkali solution is 1:2.15 to 1:2.5; The composition comprises at least an ether carboxylic acid of formula (I): Formula (I) R1-OP-CH2-COOX wherein R1 is a straight or branched alkyl or alkenyl chain having 1 to 30 carbon atoms; P comprises an average of n –(CH2CH2O)- units and / or an average of m –(CH2CHR2O)- or –(CHR2CH2O)- units and / or an average of q –(CH2CHR3O)- or –(CHR3CH2O)- units, wherein n represents a value in the range of 0 to 50, m represents a value in the range of 0 to 50, and q represents a value in the range of 0 to 50, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 100; R2 represents a –CH3 group, and R3 represents a –CH2CH3 group; and X represents a hydrogen atom or a cation selected from the group consisting of an alkali metal, ammonium, alkylammonium, alkanolammonium or gluconammonium. 2 . The preparation method according to claim 1 , wherein 5 to 50 wt % of the total amount of the alkaline solution is fed into the reactor before the C2 to C5 chlorocarboxylic acid is added.

3. The preparation method according to claim 1, wherein the feeding time of the feeding of the alkali solution before adding the C2 to C5 chlorocarboxylic acid accounts for 5% to 50% of the total time of the feeding step (ii) and the carboxyalkylation step (iii).

4. The preparation method according to claim 1, wherein the method further comprises the following steps: (iv) adding an acid after the carboxyalkylation step (iii) to convert the ether carboxylate obtained into the free ether carboxylic acid.

5. The preparation method according to any one of claims 1 to 4, wherein the method further comprises a washing step and / or a distillation step.

6. A method for preparing an oilfield composition, the method comprising adding a composition to an oilfield composition, the composition comprising at least an ether carboxylic acid of formula (I): Formula (I) R1-OP-CH2-COOX wherein R1 is a straight or branched alkyl or alkenyl chain having 1 to 30 carbon atoms; P comprises an average of n –(CH2CH2O)- units and / or an average of m –(CH2CHR2O)- or –(CHR2CH2O)- units and / or an average of q –(CH2CHR3O)- or –(CHR3CH2O)- units, wherein n represents a value in the range of 0 to 50, m represents a value in the range of 0 to 50, and q represents a value in the range of 0 to 50, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 100; R2 represents a –CH3 group, and R3 represents a –CH2CH3 group; and X represents a hydrogen atom or a cation selected from the group consisting of an alkali metal, ammonium, alkylammonium, alkanolammonium or gluconammonium, The composition comprising at least the ether carboxylic acid of formula (I) is prepared by a process comprising the following steps: i. providing an oxyalkylated alcohol compound of formula (II) in a reactor, Formula (II) R1-OPH wherein R1 is a straight or branched alkyl or alkenyl chain having 1 to 30 carbon atoms; P comprises an average of n –(CH2CH2O)- units and / or an average of m –(CH2CHR2O)- or –(CHR2CH2O)- units and / or an average of q –(CH2CHR3O)- or –(CHR3CH2O)- units; wherein n represents a value in the range of 0 to 50, m represents a value in the range of 0 to 50, and q represents a value in the range of 0 to 50, and the sum of n+m+q represents an average degree of alkoxylation corresponding to a value from 1 to 60; R2 represents a –CH3 group, and R3 represents a –CH2CH3 group; ii. feeding a base solution into the oxyalkylated alcohol compound of formula (II); and iii. Carboxylating the oxyalkylated alcohol compound of formula (II) with a C2 to C5 chlorocarboxylic acid, wherein the molar ratio between the C2 to C5 chlorocarboxylic acid and the alkali salt in the alkali solution is 1:2.15 to 1:2.5.

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