New low viscosity functional fluid

Abstract

The present invention relates to low viscosity functional fluids, particularly brake fluids, based on organosilicon compounds and alkoxy glycols.

Description

[Technical field]

[0001] The present invention describes low viscosity functional fluids, particularly brake fluids, based on organosilicon compounds and alkoxy glycols.

[0002] These brake fluids have high dry and wet boiling points and low low temperature viscosities which make them particularly suitable for modern braking systems. [Background technology]

[0003] A typical functional fluid includes a mixture of alkoxy glycols and their borate esters. They are widely used as brake fluids. The increasing demand for brake fluids requires higher dry and wet boiling points and at the same time reduced viscosity.

[0004] The current requirements of DOT5.1 are dry and wet boiling points greater than 260°C and 180°C, respectively, and a kinematic viscosity of 900mm at -40°C. 2 It is stipulated that the frequency must be less than / s.

[0005] At least one silicone ester-based brake fluid is freely available on the market, which has a silicon content of 8% by weight, i.e. is essentially a pure reaction product of an organosilicon compound with an alkoxy glycol.

[0006] According to the product data sheet, the dry and wet boiling points of this product are very high at 320°C and 270°C, respectively, but the kinetic viscosity at -40°C is 1300mm 2 / s, which means it does not meet the requirements of DOT5.1.

[0007] Such silicone ester-based fluids and their use as hydraulic oils are known from DE 2147853 A. Silicone esters are used in the examples in pure form or as blends with boric acid esters and alkoxy glycols. Blends of silicone esters and alkoxy glycols are not described.

[0008] Research Disclosure 694049, published on January 17, 2022, describes compositions consisting of silicone esters and alkoxy glycols. Neither the wet or dry boiling points of these compositions nor their viscosities are reported, so the suitability of the compositions as brake fluids cannot be evaluated. Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to maintain the advantages of the high dry and wet boiling points of silicone ester based compounds and to reduce the viscosity to at least the low level required by DOT 5.1, preferably 750 cSt (mm) at -40°C as specified by ISO 4925, Class 6. 2 The objective of the study was to develop a brake fluid with a kinetic viscosity of less than 1000 g / s. [Means for solving the problem]

[0010] This object is achieved by a functional fluid having a viscosity according to FMVSS 116 of less than or equal to 750 cSt at -40°C, said functional fluid comprising: (A) Formula (I) H 3 CO-[-CH 2 -CH 2 -O-] n -H (In the formula, n is an integer from 2 to 5, and For at least 30% by weight of all components of formula (I), n=3. at least one alkoxy glycol of (B) Formula (II) R 1 -O-[-CH 2 -CH 2 -O-] m -H (In the formula, R 1 is C 2 ~C 4 -alkyl, m is an integer from 2 to 6, and For at least 65% by weight of all components of formula (II), m=3. at least one alkoxy glycol of (C) optionally, a compound of formula (III) HO-[-CH 2 -CH 2 -O-] k -H (In the formula, k is an integer of at least 2; and For at least 80% by weight of all components of formula (III), k=2 or 3. at least one glycol of (D) at least one additive selected from the group consisting of corrosion inhibitors, amines, stabilizers, antifoam agents, and lubricants; (E) Formula (IV) R 11 x -Si(-[-O-CH 2 -CH 2 -] z -OR 12 ) 4-x (In the formula, x is a positive integer 1, 2 or 3, preferably 2; z is an integer from 2 to 4; R 11 is C 1 ~C 4 - alkyl, in particular methyl or ethyl, more preferably methyl, and R 12 is C 1 ~C 4 -alkyl, in particular methyl or n-butyl, more preferably methyl). At least one organosilicon compound of Including, The proportion of (E) is 40% by weight to 55% by weight, preferably 43% by weight to 55% by weight, more preferably 45% by weight to 53% by weight, and most preferably 47% by weight to 52% by weight, The proportion of (A) is 24% by weight to 45% by weight, The proportion of (B) is 5% by weight to 20% by weight, preferably 7% by weight to 15% by weight, The proportion of (C) is 0% by weight to 10% by weight, preferably 0% by weight to 5% by weight, The proportion of (D) is more than 0% by weight and 5% by weight, However, the total of all components (A) to (E) must always be 100% by weight, In components (A) to (C) and (E), - the sum of all alkoxy glycols or glycols where n, m, k and z=2 is greater than 0 (zero) mol % and less than or equal to 10 mol %; - the sum of all alkoxy glycols or glycols where n, m, k and z=3 is at least 60 mol %; and - the sum of all alkoxy glycols or glycols where n, m, k and z=4 is greater than 0 mol % to 20 mol %; and the proportion of alkoxy glycols or boric acid esters with glycols is not more than 3% by weight; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Silicone ester-based compounds have high dry and wet boiling points, but are too viscous, whereas low molecular weight glycols or alkoxy glycols have low viscosity and low boiling points.However, the higher the selected level of alkoxylation of alkoxy glycols, the greater the increase in their boiling point, but at the same time the advantage of low viscosity is lost.

[0012] The functional fluids of the present invention have low viscosities that meet the above requirements, despite their high dry and wet boiling point values. These properties are achieved by selecting a balanced combination of compounds that exhibit high dry and wet boiling points and low viscosity. In particular, the alkoxylation level of the glycols or alkoxy glycols is selected so that these compounds achieve a compromise between a sufficiently high boiling point and a sufficiently low viscosity.

[0013] Triethylene glycol-based glycols and alkoxy glycols have been found to provide this compromise between low viscosity and high dry or wet boiling points, and therefore these species make up the majority of functional fluids, at least 60%.

[0014] Glycols and alkoxy glycols based on diethylene glycol have a low viscosity, but because of the low boiling points required, their proportion is 10% or less.

[0015] Conversely, glycols and alkoxy glycols based on tetraethylene glycol have a high boiling point but at the same time a relatively high viscosity, and therefore their proportion is less than 20%.

[0016] Glycol has a relatively high viscosity due to its two free hydroxyl groups, so the proportion of glycol in the functional fluid should not exceed 10% by weight, preferably 5% by weight.

[0017] The percentages herein are based on the mole percent of the oligomers of each of components (A), (B), (C) and (E), taking into account that the alkoxy glycol in component (E) is incorporated at (4-x) times.

[0018] These components are described individually as follows: Component (A) is a compound represented by the formula (I) H 3 CO-[-CH 2 -CH 2 -O-] n -H (In the formula, n is an integer from 2 to 5, preferably from 2 to 4, more preferably 3 or 4; and For at least 30% by weight of all components of formula (I), n=3. At least one alkoxy glycol selected from the group consisting of

[0019] These may be 1 to 4, preferably 1 to 3, more preferably 1 or 2, most preferably 1 alkoxy glycol.

[0020] Exemplary components (A) are diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether and pentaethylene glycol monomethyl ether.

[0021] Of these, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether and tetraethylene glycol monomethyl ether are preferred, triethylene glycol monomethyl ether and tetraethylene glycol monomethyl ether are particularly preferred, and triethylene glycol monomethyl ether is very particularly preferred.

[0022] Typically, component (A) is a mixture primarily consisting of triethylene glycol monomethyl ether and tetraethylene glycol monomethyl ether, with the higher and lower alkylene glycol monomethyl ethers each accounting for less than 10% by weight, more preferably less than 10% by weight in total. Most preferably, component (A) is primarily triethylene glycol monomethyl ether, with the higher and lower alkylene glycol monomethyl ethers each accounting for less than 20% by weight, more preferably less than 10% by weight in total.

[0023] The proportion of triethylene glycol monomethyl ether in component (A) is at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, most preferably at least 60% by weight.

[0024] In a preferred embodiment, the proportion of triethylene glycol monomethyl ether in component (A) is at least 75% by weight, more preferably at least 85% by weight, even more preferably at least 90% by weight and in particular at least 95% by weight.

[0025] Component (B) is a compound represented by the formula (II) R 1 -O-[-CH 2 -CH 2 -O-] m -H (In the formula, R 1 is C 2 ~C 4 -alkyl, preferably ethyl, n-propyl, n-butyl, more preferably ethyl and n-butyl, most preferably n-butyl; m is an integer from 2 to 6, preferably from 2 to 5, more preferably from 2 to 4, and most preferably 3 or 4; and For at least 65% by weight of all components of formula (II), m=3. At least one alkoxy glycol selected from the group consisting of

[0026] These may be 1 to 5, preferably 1 to 4, more preferably 1 to 3, most preferably 1 or 2, especially 1 alkoxy glycol.

[0027] Preferred compounds (B) are the corresponding oligoethylene glycol monoethyl ethers, oligoethylene glycol mono-n-propyl ethers and oligoethylene glycol mono-n-butyl ethers, more preferably oligoethylene glycol monoethyl ether and oligoethylene glycol mono-n-butyl ether, most preferably oligoethylene glycol mono-n-butyl ether.

[0028] The oligoethylene glycol monoalkyl ethers are preferably diethylene glycol monoalkyl ethers, triethylene glycol monoalkyl ethers, tetraethylene glycol monoalkyl ethers and pentaethylene glycol monoalkyl ethers, more preferably diethylene glycol monoalkyl ethers, triethylene glycol monoalkyl ethers and tetraethylene glycol monoalkyl ethers, even more preferably triethylene glycol monoalkyl ethers and tetraethylene glycol monoalkyl ethers, in particular triethylene glycol monoalkyl ethers.

[0029] In a preferred embodiment, component (B) is a mixture consisting essentially of triethylene glycol mono-n-butyl ether and tetraethylene glycol mono-n-butyl ether, with the higher and lower alkylene glycol monoalkyl ethers each comprising less than 10% by weight, more preferably less than 10% by weight in total. Most preferably, component (B) is primarily triethylene glycol mono-n-butyl ether, with the higher and lower alkylene glycol monoalkyl ethers each comprising less than 20% by weight, more preferably less than 10% by weight in total.

[0030] The proportion of triethylene glycol monoalkyl ether in component (B) is at least 65% by weight, preferably at least 70% by weight, more preferably at least 75% by weight, most preferably at least 80% by weight.

[0031] Optional component (C) is a compound represented by formula (III): HO-[-CH 2 -CH 2 -O-] k -H (In the formula, k is an integer of at least 2; and For at least 80% by weight of all components of formula (III), k=2 or 3. For example, the compound contains 1 to 4, preferably 1 to 3, more preferably 1 or 2, and most preferably 1 compound.

[0032] Examples of such compounds are diethylene glycol, triethylene glycol, tetraethylene glycol and pentaethylene glycol, preferably diethylene glycol, triethylene glycol and tetraethylene glycol, more preferably diethylene glycol and triethylene glycol.

[0033] Preferably, at least 80% by weight, more preferably at least 85% by weight, even more preferably at least 90% by weight, especially at least 95% by weight of all components (C) are diethylene glycol and triethylene glycol. In a preferred embodiment, at least 60% by weight, preferably at least 75% by weight, even more preferably at least 85% by weight, especially at least 90% by weight of component (C) is diethylene glycol.

[0034] Furthermore, the brake fluid of the present invention also contains, as component (D), at least one additive selected from the group consisting of corrosion inhibitors, amines, stabilizers, antifoam agents and lubricants.

[0035] Component (D) is selected from the group consisting of alkylamine ethoxylates, alkanolamines, fatty acids, phosphonates, phosphates, heterocyclic nitrogen-containing organic compounds, alkylamines, phenothiazines, phenolic compounds, ricinoleic acid, alkoxylates of castor oil or any other ricinoleic acid esters and ethoxylated phenols and C esters having an ethoxylation level of 10 to 100. 1 -C 20 -alkanols.

[0036] Component (D) which may be present in the functional fluid composition is preferably an additive package comprising one or more additives having a corrosion inhibitory effect. Preferably, at least one additive having a corrosion inhibitory effect is selected from alkylamine ethoxylates and alkanolamines, preferably from the group consisting of alkylamine ethoxylates and trialkanolamines.

[0037] The alkylamine group in the aforementioned alkylamine ethoxylates can be a secondary or preferably primary aliphatic monoamine that can be ethoxylated.Typically, a secondary or preferably primary aliphatic monoamine is used, but it is also possible to use a polyamine having at least one secondary and / or primary amino group that can be ethoxylated.The alkyl group of the nitrogen atom usually comprises a saturated linear or branched alkyl group, but an unsaturated linear or branched alkyl group or a saturated or unsaturated cycloalkyl group can also be included in the term "alkyl group".

[0038] In a preferred embodiment, the alkylamine ethoxylate comprises at least one linear or branched C 3 ~C 20 - alkyl chains, preferably at least one linear or branched 6 ~C 13 - an alkyl chain, more preferably at least one linear or branched C 7 ~C 12 - an alkyl chain, most preferably at least one linear or branched C 8 ~C 10 -Alkyl chains, particularly preferably linear C 8 -alkyl chains. In this specification, the term "alkyl chain" preferably means a saturated and non-cyclic hydrocarbyl group, more preferably a straight-chain unbranched alkyl group. The alkylamine ethoxylates may also contain mixtures of such alkyl chains, for example mixtures of homologous alkyl groups, depending on the particular technical or natural origin of the alkylamine used.

[0039] Suitable examples of individual alkylamine molecules that can be ethoxylated and are also suitable as surfactants in the present invention are n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-pentylamine, tert-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-ethylhexylamine, n-nonylamine, n-decylamine, 2-propylheptylamine, n-un ... Decylamine, n-dodecylamine, n-tridecylamine, isotridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-nonadecylamine, n-eicosylamine, di(n-hexyl)amine, di(n-heptyl)amine, di(n-octyl)amine, di(2-ethylhexyl)amine, di(n-nonyl)amine, di(n-decyl)amine, di(2-propylheptyl)amine )amine, di(n-undecyl)amine, di(n-dodecyl)amine, di(n-tridecyl)amine, di(isotridecyl)amine, di(n-tetradecyl)amine, di(n-pentadecyl)amine, di(n-hexadecyl)amine, di(n-heptadecyl)amine, di(n-octadecyl)amine, di(n-nonadecyl)amine, di(n-eicosyl)amine, n-hexylmethylamine, n-heptylmethylamine, n-octylmethylamine, (2-ethylhexyl) )methylamine, n-nonylmethylamine, n-decylmethylamine, (2-propylheptyl)methylamine, n-undecylmethylamine, n-dodecylmethylamine, n-tridecylmethylamine, isotridecylmethylamine, n-tetradecylmethylamine, n-pentadecylmethylamine, n-hexadecylmethylamine, n-heptadecylmethylamine, n-octadecylmethylamine, n-nonadecylmethylamine and n-eicosylmethylamine.

[0040] Such alkyl groups are found in petrochemicals, e.g., industrial grade C 8 ~C 15The alkylamine ethoxylates may be derived entirely from alkyl amine mixtures, 2-ethylhexyl or 2-propylheptyl, or may be based wholly or partially on renewable raw materials, for example fatty amines such as stearyl, and the base used in the alkylamine ethoxylates may be amine, oleylamine or tallowamine.

[0041] The ethoxylation level is generally 1 to 35 ethylene oxide ("EO") units per alkylamine molecule, meaning that at least one alkylamine ethoxylate contains 1 to 35 EO units, preferably 1.5 to 15 EO units, more preferably 1.8 to 9 EO units, and most preferably 2 to 6 EO units. The aforementioned ethoxylation levels are statistical values, i.e., alkylamine ethoxylates should usually be considered as a mixture of species (homologs) having different numbers of EO units. In a particularly preferred embodiment of the present invention, at least one alkylamine ethoxylate contains at least one linear C 3 ~C 20 -alkyl chain and 1 to 35 EO units, and at least one alkylamine ethoxylate is more preferably at least one linear C 6 ~C 13 -alkyl chain and 1.5 to 15 EO units, and at least one alkylamine ethoxylate is most preferably at least one linear C 7 ~C 11 - alkyl chain and 1.8 to 9 EO units, in particular at least one alkylamine ethoxylate having at least one linear C 8 ~C 10 -containing an alkyl chain and 2 to 6 EO units.

[0042] Such alkylamine ethoxylates have the general formula alkyl-NH-(CH 2 CH 2 O) m -H, or a primary amine with one oxyethylene chain of the general formula alkyl-N[(CH 2 CH 2 O) p H][(CH 2 CH2 O) q -H], or a primary amine having two oxyethylene chains of the general formula (alkyl) 2 N-(CH 2 CH 2 O) m H secondary amines, or mixtures of these primary amines having one oxyethylene chain and these primary amines having two oxyethylene chains, or mixtures of such primary and secondary amines, where m and (p+q) are the total ethoxylation levels. The "alkyl" in the above formula is usually a C, as defined above. 3 ~C 20 -Alkyl, preferably C 6 ~C 13 -alkyl, more preferably C 7 ~C 12 -alkyl, most preferably C 8 ~C 10 -alkyl. Other alkylamine species may also be present in relatively small amounts, especially when the total degree of ethoxylation is low, below 2.

[0043] A typical suitable alkylamine ethoxylate is octylamine (caprylamine), which has two EO units, and is commercially available.

[0044] The aforementioned alkylamine ethoxylates can be prepared by conventional methods, such as the reaction of alkylamines with ethylene oxide catalyzed by alkali metal hydroxides or double metal cyanides, as known to those skilled in the art. Some alkylamine ethoxylates have corrosion inhibition properties, and some have solvent properties for the functional fluid composition or brake fluid according to the present invention.

[0045] Component (D) of the functional fluid composition of the present invention may contain, in addition to the alkylamine ethoxylate, at least further additives having a corrosion inhibitor action.

[0046] Suitable conventional additives having corrosion inhibiting properties include fatty acids such as lauric acid, palmitic acid, stearic acid or oleic acid, esters of phosphonic or phosphoric acid with fatty alcohols, phosphites and phosphites such as ethyl phosphite, dimethyl phosphite, isopropyl phosphite, n-butyl phosphite, triphenyl phosphite and diisopropyl phosphite, reaction products of phosphorus pentoxide with the alkoxy glycols mentioned above as component (A) or (B), heterocyclic nitrogen-containing organic compounds such as benzotriazole, tolutriazole, 1,2,4-triazole, benzimidazole, purine, adenine and derivatives of such heterocyclic organic compounds, mono- and di-(C 4 ~C 20 amines, such as n-butylamine, n-hexylamine, n-octylamine, 2-ethylhexylamine, isononylamine, n-decylamine, n-dodecylamine, oleylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, di-n-amylamine, cyclohexylamine and salts of such alkylamines, and alkanolamines, such as mono-, di- and trimethanolamine, mono-, di- and triethanolamine, mono-, di- and tri-n-propanolamine and mono-, di- and triisopropanolamine. Triethanolamine and triisopropanolamine are preferred, and triisopropanolamine is particularly preferred.

[0047] Naturally, it is also possible to use mixtures of the aforementioned additives which have a corrosion-inhibiting effect.

[0048] In addition to the alkylamine ethoxylates and any additives with corrosion-inhibiting action, the additive package of component (D) can contain further customary additives, for example stabilizers, such as pH stabilizers, antioxidants, such as phenothiazines and phenolic compounds, for example hydroxyanisole and bisphenol A, antifoam agents and dyes.

[0049] In a preferred embodiment, component (D) comprises as lubricant at least one alkoxylate of ricinoleic acid, castor oil or any other ricinoleic acid ester, preferably ricinoleic acid or castor oil, most preferably castor oil, which in the context of this specification is an at least partially, preferably fully esterified acylglycerol, in which at least one of the acyl groups, preferably at least two of the acyl groups, is ricinoleic acid or isoricinoleic acid, preferably ricinoleic acid.

[0050] For example, the mixture of fatty acids preferably comprises a mixture of two molecules of ricinoleic acid with a fatty acid that does not have a hydroxyl group selected from the group consisting of oleic acid, linoleic acid, palmitic acid and stearic acid.

[0051] In a preferred embodiment, the OH value of the castor oil is 160-173 mg KOH / g. The alkoxylates of ricinoleic acid, castor oil or any other ricinoleic acid esters may be saturated or unsaturated hydroxy-substituted C 8 ~C 22 It is preferably prepared by conversion of a fatty acid or its ester, in particular by reaction of ricinoleic acid, castor oil or some other ricinoleic acid ester with at least one alkylene oxide. The alkylene oxide may be propylene oxide, butylene oxide, styrene oxide or preferably ethylene oxide. Mixtures of such alkylene oxides resulting in random or block structures of alkylene oxide units may be used as well.

[0052] Specifically, the structure of the alkoxylate preferably comprises, when a free carboxylic acid functional group is present in the molecule, a saturated or unsaturated C 8 ~C 22 Aliphatic monocarboxylic acid or at least one saturated or unsaturated C 8 ~C 22The alkoxylates are based on saturated or unsaturated hydroxy-substituted C alkoxylates, which contain aliphatic monocarboxylic acid units and have hydroxyl groups present on the fatty acid side chains of the alkoxylates etherified with one or more oxyalkylene units. 8 ~C 22 Aliphatic monocarboxylic acids or units thereof, preferably saturated or unsaturated hydroxy-substituted C 14 ~C 20 Examples of aliphatic monocarboxylic acids or units thereof are 10-hydroxystearic acid, 12-hydroxystearic acid, and in particular ricinoleic acid. 8 ~C 22 Aliphatic monocarboxylic acids can be used as free carboxylic acids or the corresponding esters for the preparation of alkoxylates. In the case of ricinoleic acid, castor oil in the form of its naturally occurring triglyceride can be advantageously reacted with alkylene oxide in the form of transesterification to obtain the desired ricinoleic acid alkoxylates and glycerol. The reactants used in the transesterification can be any other esters of ricinoleic acid, such as the corresponding diglycerides or monoglycerides or the corresponding methyl, ethyl, propyl or butyl esters. Depending on the conditions of the alkoxylation reaction of the esters of ricinoleic acid, especially with castor oil, the esters can retain their carboxyl esters, especially their glycerol triester functions, and are mono- or polyalkoxylated by oxyalkylene units only at the hydroxyl groups of the fatty acid side chains.

[0053] The aforementioned alkoxylates, in particular the alkoxylates of ricinoleic acid, castor oil or any other ricinoleic acid ester, typically contain 2 to 200, preferably 4 to 100, more preferably 6 to 80, most preferably 10 to 50, especially 20 to 40, alkylene oxide units, preferably ethylene oxide units. The "number of alkylene oxide units" refers to the number of saturated or unsaturated hydroxyl-substituted C alkylene oxide units on which the alkoxylate is based. 8 ~C 22It means the number of moles of alkylene oxide per mole of aliphatic monocarboxylic acid or its unit. When using castor oil, which is a triglyceride of ricinoleic acid, the amount of alkylene oxide used for alkoxylation is based on three equivalents of ricinoleic acid or its unit to be alkoxylated. At high degrees of alkoxylation, the number of alkylene units is an average as a statistical number, as a result of the distribution of alkoxylated homologues in the product. There may be two types of hydroxyl groups in the molecule to be alkoxylated, i.e., one is esterified (or transesterified) and the other is etherified; esterification may or may not occur, but etherification always occurs.

[0054] Methods for the alkoxylation, and in particular the ethoxylation, of carboxylic acids or esters thereof, such as castor oil, are known in the prior art and therefore do not require further description in the present application.

[0055] In a preferred embodiment, the functional fluid of the present invention comprises at least one compound selected from the group consisting of benzotriazole, tolutriazole, 1,2,4-triazole and benzimidazole.

[0056] In a further preferred embodiment, the functional fluid of the present invention additionally or independently preferably comprises linear C 8 ~C 10 - at least one compound selected from the group consisting of alkylamine ethoxylates having an alkyl chain and 2 to 6 EO units, mono-, di- and triisopropanolamines.

[0057] In a further preferred embodiment, the functional fluid of the present invention additionally or independently preferably further comprises at least one 10-50 fold ethoxylated alkoxylate of ricinoleic acid, castor oil or other ricinoleic acid ester.

[0058] The defoamers as component (D) are typically ethoxylated phenols and C 2 hydroxyl groups having an ethoxylation level of 10 to 100 ethylene oxide ("EO") units per hydroxyl group. 1 ~C 20 Alkanol, preferably 15-75 times ethoxylated C 1 ~C 20 It is an alkanol.

[0059] In addition, the brake fluid of the present invention comprises a compound represented by the formula (IV) R 11 x -Si(-[-O-CH 2 -CH 2 -] z -OR 12 ) 4-x (In the formula, x is a positive integer 1, 2 or 3, preferably 1 or 2, more preferably 2; z is an integer from 2 to 4, preferably 3; R 11 is C 1 ~C 4 - alkyl, in particular methyl or ethyl, more preferably methyl, and R 12 is C 1 ~C 4 -alkyl, in particular methyl or n-butyl, more preferably methyl). The compound also contains at least one organosilicon compound (E).

[0060] As mentioned above, these organosilicon compounds, especially those with x=1 and 2, especially those with x=2, have high wet and dry boiling points. The presence of these compounds (E) in brake fluids increases their boiling points, but also generally increases their viscosity. The goal is therefore to select the proportion of component (E) as high as necessary to achieve the desired boiling point, while selecting the type and amount of components (A)-(C), especially (A) and (B), to reduce the high viscosity of component (E) while at the same time having wet and dry boiling points high enough to meet the desired parameters themselves.

[0061] For this purpose, the brake fluid according to the invention comprises at least one organosilicon compound (E), preferably 1 to 4, more preferably 1 to 3, even more preferably 1 or 2, in particular 1.

[0062] In compound (E), R 11 The group is C 1 ~C 4 -alkyl, preferably methyl, ethyl or n-butyl, more preferably methyl or ethyl, most preferably methyl. 11 The groups can independently be the same or different, but are preferably the same.

[0063] R 11 The number x of groups is 1 to 3, preferably 1 or 2, and more preferably 2.

[0064] Substructure H-[-O-CH 2 -CH 2 -] z -OR 12 is the alkylene glycol monoalkyl ether as described above for compounds (A) and (B), and R 12 is preferably C 1 ~C 4 -alkyl, preferably methyl, ethyl or n-butyl, more preferably methyl or n-butyl, most preferably methyl. The serial index z is a positive integer from 2 to 4, preferably 3 or 4, more preferably 3.

[0065] In a preferred embodiment, the substructure H-[-O-CH 2 -CH 2 -] z -OR 12is selected from the group consisting of diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, diethylene glycol mono n-butyl ether, triethylene glycol mono n-butyl ether and tetraethylene glycol mono n-butyl ether, preferably triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, triethylene glycol mono n-butyl ether and tetraethylene glycol mono n-butyl ether, more preferably triethylene glycol monomethyl ether and triethylene glycol mono n-butyl ether.

[0066] In a preferred embodiment, the substructure H-[-O-CH 2 -CH 2 -] z -OR 12 is the same alkylene glycol monoalkyl ether used as component (A) and / or (B), more preferably the same alkylene glycol monoalkyl ether used as component (A).

[0067] The composition of the functional fluid of the present invention, preferably the brake fluid of the present invention, is as follows: Component (E) is 40% by weight to 55% by weight, preferably 43% by weight to 55% by weight, more preferably 45% by weight to 53% by weight, and most preferably 47% by weight to 52% by weight; Component (A) is 24% by weight to 45% by weight, preferably 24% by weight to 40% by weight, more preferably 24% by weight to 35% by weight, and most preferably 24% by weight to 30% by weight, (B) is 5% by weight to 20% by weight, preferably 7% by weight to 15% by weight, (C) is 0% by weight to 10% by weight, preferably 0% by weight to 5% by weight, (D) is from more than 0% by weight to 5% by weight, preferably from 1% by weight to 4% by weight; However, the total of all components (A) to (E) must always be 100% by weight.

[0068] In a preferred embodiment of the present invention, the content of glycol (C) in the functional fluid of the present invention does not exceed the proportion of glycol resulting from the production of components (A) and (B), i.e. no additional glycol (C) is added to the functional fluid. More preferably, the proportion of glycol (C) in the functional fluid of the present invention is less than 1% by weight, preferably less than 0.75% by weight, most preferably less than 0.5% by weight.

[0069] In another preferred embodiment of the invention, at least one glycol (C) is present, more preferably in an amount that exceeds the proportion of glycols resulting from the production of components (A) and (B), most preferably in an amount of from 1% to 10% by weight, in particular from 1% to 5% by weight.

[0070] This embodiment is particularly preferred when the presence of a polynuclear organosilicon compound (see below) is desired.

[0071] However, in components (A) to (C) and (E), - the sum of all alkoxy glycols or glycols where n, m, k and z=2 is greater than 0 (zero) mol % and less than or equal to 10 mol %, - the sum of all alkoxy glycols or glycols where n, m, k and z=3 is at least 60 mol %; and - with the proviso that the sum of all alkoxy glycols or glycols where n, m, k and z=4 is greater than 0 mol % to 20 mol %.

[0072] In addition, the proportion of alkoxy glycols or boric acid esters with glycols is at most 3% by weight, preferably at most 2.5% by weight, more preferably at most 2% by weight, even more preferably at most 1.5% by weight, in particular at most 1% by weight, especially at most 0.5% by weight.

[0073] Since components (A), (B) and (C) contain reactive groups capable of reacting with the organosilicon compound (E), the composition of the functional fluid of the present invention may vary, for example, at temperatures above room temperature and / or under the influence of storage. In addition, such reactions may be accelerated by the presence of an amine as additive (D).

[0074] This variation in composition is due first to the partial structure H-[-O-CH 2 -CH 2 -] z -OR 12 with alkylene glycol monoalkyl ethers (A) and (B), such that the alkylene glycol monoalkyl ethers (A) and (B) are incorporated into component (E) and the free alkylene glycol monoalkyl ethers H-[-O-CH 2 -CH 2 -] z -OR 12 is formed in the composition. Meanwhile, in the presence of difunctional diglycol (C), polynuclear organosilicon compounds, i.e. compounds with more than one silicon atom, can also be formed. For example, binuclear or trinuclear silicon compounds can be formed, and those with a large number of nuclei are only formed in small amounts, and preferably binuclear silicon compounds are formed.

[0075] The structure of such a dinuclear silicon compound is, for example, as follows: R 11 x -Si(-[-O-CH 2 -CH 2 -] z -OR 12 ) 4-x-1 -(-O-[-CH 2 -CH 2 -O-] k -)-Si R 11 x (-[-O-CH 2 -CH 2 -] z -OR 12 ) 4-x-1 where the variables are as defined above, and where x must be at least 2.

[0076] The structure of the trinuclear silicon compound is, for example, as follows: R 11 x -Si(-[-O-CH 2 -CH 2 -] z -OR 12 ) 4-x-1 -(-O-[-CH 2 -CH 2 -O-] k -)-Si R 11 x (-[-O-CH 2 -CH 2 -] z -OR 12 ) 4-x-2 -(-O-[-CH 2 -CH 2 -O-] k -)-Si R 11 x (-[-O-CH 2 -CH 2 -] z -OR 12 ) 4-x-1 where the variables are as defined above, and where x must be at least 2.

[0077] This variation reaches its highest degree in the composition of the mixture of all components (A)-(E) established in a thermodynamic equilibrium progression from the initial composition.

[0078] Thus, the present invention further provides a reaction mixture obtainable by the mutual reaction of components (A) to (E). When diglycol (C) is present, the reaction mixture may also contain polynuclear silicon compounds, such as dinuclear and trinuclear, preferably dinuclear silicon compounds.

[0079] The composition of the reaction mixture is between the initial composition and the composition at thermodynamic equilibrium.

[0080] The mixtures of the present invention may be used as functional fluids, such as hydraulic fluids, in particular brake fluids.

[0081] Brake fluids can be used advantageously in particular in vehicles equipped with hydraulic brake systems, such as passenger cars or utility vehicles, and are particularly suitable for electronic or automatic brake systems equipped with anti-lock systems, which require a brake fluid with low viscosity even at low temperatures.

[0082] The following examples are intended to illustrate the scope and advantages of the compositions of the present invention, but are not intended to be limiting. EXAMPLES

[0083] The brake fluid used as an example was Castrol React SRF Racing with a Si content of about 8.0 wt% + / - 0.3 wt% (within the measurement accuracy) as determined by ICP-OES. In theory, this is essentially the same as for x=2, z=3 and R 11 and R 12 are C 1 ~C 4 This corresponds to a pure silicone ester having triethylene glycol monoalkyl ether as the incorporated alkoxy glycol (compound (E)) which is -alkyl, and is referred to herein as component 1.

[0084] The following formulations were made and their properties determined as follows: Dry boiling point (ERBP) conforms to ASTM D1120. Wet boiling point (WERBP) conforms to SAE J1703. Kinematic viscosity according to ASTM D445, at -40°C unless otherwise stated.

[0085] Example 1

[0086] [Table 1]

[0087] MTG: Triethylene glycol monomethyl ether (compound (A), n=3) BTG: Triethylene glycol monobutyl ether (compound (B), m = 3, R 1 = n-butyl) MTG Borate: A borate ester of MTG (B(MTG) 3 )

[0088] It can be seen that the pure silicone ester has slightly higher ERBP and WERBP values ​​but a much higher low temperature viscosity compared to the pure borate ester (entry 1 vs. 4).

[0089] When blended with alkyl glycol ethers, the silicone ester-based mixtures maintain and even extend those advantages of ERBP and WERBP, and the viscosity can be substantially reduced to the level of the borate ester-based mixtures (entries 2 vs. 5 and 3 vs. 6).

[0090] Example 2 A formulation of the following composition (by weight) was prepared:

[0091] [Table 2]

[0092] BTG: Triethylene glycol mono-n-butyl ether (compound (B), m = 3, R 1 = n-butyl) MTG: Triethylene glycol monomethyl ether (compound (A), n=3) MTeG: Tetraethylene glycol monomethyl ether (compound (A), n=4) DEG: Diethylene glycol (compound (C), k=2) Additive mixture: 2.5% corrosion inhibitor, 2.5% and 10.0% lubricant, composition FFC4, 0.25% anionic wetting aid, 1.5% amine antioxidant as heat stabilizer, as described in WO 2015 / 052234, dissolved in 83.25% MTG.

[0093] In addition, Examples 3, 4, 6 and 8 reported in Research Disclosure 694049 published on January 17, 2022 were reprocessed to obtain a viscosity at -40°C [mm 2 / s], ERBP [°C] and WERBP [°C] were determined in the same manner as in Example 2.

[0094] [Table 3]

[0095] Comparative Example RD3 has a similar content of Component 1 and MTG as Example 2, but contains 24 wt. % BTG, whereas Example 2 contains only 10 wt. % BTG, but also 10 wt. % MTaG.

[0096] This results in roughly comparable viscosity and dry boiling point (ERBP) at -40°C, but invention example 2 has a 13°C higher wet boiling point (WERBP) than comparative example RD3.

[0097] Therefore, MTaG as component (A) of the present invention with n=4 shows a more favorable effect on the wet boiling point than increasing the content of triethylene glycol mono-n-butyl ether (BTG), while at the same time maintaining good values ​​of viscosity and dry boiling point.

[0098] Comparative Example RD8 has a similar content of component 1 and MTG as Example 3, but contains only 2 wt% BTG, whereas the BTG content of Example 2 is 10 wt%.

[0099] This results in roughly comparable viscosity and dry boiling points (ERBP) at -40°C, but invention example 3 has a 4°C higher wet boiling point (WERBP) than comparative example RD8.

[0100] Therefore, the increase in BTG content (component (B), m = 3, R 1butyl) has a favorable effect on the wet boiling point while at the same time maintaining good values ​​of viscosity and dry boiling point.

Claims

1. At -40°C, 750 cSt (mm ２ A functional fluid having a viscosity of FMVSS116 of less than or equal to / s, (A) Formula (I) H ３ C-O-[-CH ２ -CH ２ -O-] ｎ -H (In the formula, n is an integer between 2 and 5, and (For at least 30% by weight of all components of formula (I) above, n = 3) at least one alkoxy glycol, (B) Formula (II) R １ -O-[-CH ２ -CH ２ -O-] ｍ -H (In the formula, R １ C ２ ~C ４ -It is alkyl, m is an integer between 2 and 6, and (For at least 65% by weight of all components of formula (II) above, m = 3.) at least one alkoxy glycol, (C) Optionally, equation (III) H-O-[-CH ２ -CH ２ -O-] ｋ -H (In the formula, k is an integer of at least 2, and At least 80% by weight of all components of the above formula (III) is at least one glycol of (k = 2 or 3), (D) At least one additive selected from the group consisting of corrosion inhibitors, amines, stabilizers, defoamers and lubricants, (E) Formula (IV) R １１ ｘ -Si(-[-O-CH ２ -CH ２ -] ｚ -O-R １２ ) ４－ｘ (In the formula, x is a positive integer 1, 2, or 3, preferably 2. z is an integer between 2 and 4. R １１ C １ ~C ４ - Alkyl, particularly methyl or ethyl, more preferably methyl, and R １２ C １ ~C ４ - Alkyl, particularly methyl or n-butyl, more preferably methyl) at least one organosilicon compound Includes, The proportion of (E) is 40% to 55% by weight, preferably 43% to 55% by weight, more preferably 45% to 53% by weight, and most preferably 47% to 52% by weight. The proportion of (A) is between 24% by weight and 45% by weight. The proportion of (B) is 5% to 20% by weight, preferably 7% to 15% by weight. The proportion of (C) is 0% to 10% by weight, preferably 0% to 5% by weight. The proportion of (D) is greater than 0% by weight and 5% by weight. However, the sum of all components (A) to (E) must always be 100% by weight. In components (A) to (C) and (E), - The total amount of all alkoxy glycols or glycols where n, m, k, and z = 2 is greater than 0 mol% and 10 mol% or less. - The total amount of all alkoxy glycols or glycols where n, m, k, and z = 3 is at least 60 mol%, and - The total amount of all alkoxy glycols or glycols where n, m, k, and z = 4 is greater than 0 mol% and 20 mol%, and - A functional fluid in which the proportion of alkoxy glycol or glycol to boric acid ester is 3% by weight or less.

2. The composition according to claim 1, wherein component (A) mainly consists of triethylene glycol monomethyl ether and tetraethylene glycol monomethyl ether.

3. The composition according to claim 1, wherein the proportion of triethylene glycol monomethyl ether in component (A) is at least 75% by weight, more preferably at least 85% by weight, even more preferably at least 90% by weight, and particularly at least 95% by weight.

4. The composition according to claim 1, wherein component (B) is selected from the group consisting of triethylene glycol mono-n-butyl ether and tetraethylene glycol mono-n-butyl ether.

5. The composition according to claim 1, wherein component (C) is selected from the group consisting of diethylene glycol and triethylene glycol.

6. The composition according to claim 1, wherein component (D) comprises at least one compound selected from the group consisting of alkylamine ethoxylates, alkanolamines, heterocyclic nitrogen-containing organic compounds, and alkoxylates of ricinoleic acid, castor oil, or any other ricinoleic acid ester.

7. The composition according to claim 1, wherein x = 2 in component (E).

8. In component (E), R １１ The composition according to claim 1, wherein is methyl.

9. The composition according to claim 1, wherein z = 3 in component (E).

10. In component (E), R １２ The composition according to claim 1, wherein is methyl.

11. Substructure of component (E) H-[-O-CH ２ -CH ２ -] ｚ -O-R １２ The composition according to claim 1, wherein is the same alkylene glycol monoalkyl ether used as component (A) and / or (B), more preferably the same alkylene glycol monoalkyl ether used as component (A).

12. A reaction mixture that can be obtained by the mutual reaction of components (A) to (E) described in claim 1.

13. The reaction mixture according to claim 12, comprising at least one diglycol (C) and at least one polynuclear silicon compound, for example, a dinuclear or trinuclear, preferably a dinuclear silicon compound.

14. The aforementioned polynuclear silicon compound is R １１ ｘ -Si(-[-O-CH ２ -CH ２ -] ｚ -O-R １２ ) ４－ｘ－１ -( -O-[ -CH ２ -CH ２ -O-] ｋ -)-Si R １１ ｘ (-[-O-CH ２ -CH ２ -] ｚ -O-R １２ ) ４－ｘ－１ and R １１ ｘ -Si(-[-O-CH ２ -CH ２ -] ｚ -O-R １２ ) ４－ｘ－１ -(-O-[-CH ２ -CH ２ -O-] ｋ -)-Si R １１ ｘ (-[-O-CH ２ -CH ２ -] ｚ -O-R １２ ) ４－ｘ－２ -(-O-[-CH ２ -CH ２ -O-] ｋ -)-Si R １１ ｘ (-[-O-CH ２ -CH ２ -] ｚ -O-R １２ ) ４－ｘ－１ The reaction mixture according to claim 13, selected from the group consisting of, wherein the variable is as described in claim 1, and x is at least 2.

15. Use of the composition and reaction mixture according to any one of claims 1 to 14 as a functional fluid, preferably a hydraulic fluid or brake fluid.