Low viscosity functional fluid composition

Abstract

This invention relates to a functional fluid, comprising (A) from 70 to 90, preferably 75-87 wt.-% of alkoxy glycol according to formula (I) CH.sub.3O(CH.sub.2CH.sub.2O).sub.nH wherein n is a number from 2 to 5, with the proviso that in at least 30 wt.-% of all compounds according to formula (I) n is 3, and that 15 to 65 wt.-% of all compounds according to formula (I) have n=4 or 5, and (B) less than 1.0 wt.-% of alkoxy glycol according to formula (II) R.sub.1O(CH.sub.2CH.sub.2O).sub.mH wherein R.sub.1 is a C.sub.2 to C.sub.8 alkyl residue, m is a number from 2 to 6, (C) from 8 to 25, preferably 12-23 wt.-% of at least one compound according to formula (III) HO(CH.sub.2CH.sub.2O).sub.kH wherein k is a number of 2 or higher, with the proviso that in at least 80 wt.-% of all compounds according to formula (III) k is 2 or 3, (D) at least one additive, selected from the group consisting of corrosion inhibitors, alkalinity agents, aging protection agents, defoamers and lubricants, the lubricants being selected from the group consisting of propylene oxide containing alkylene oxide polymers that are optionally substituted with a C.sub.1 to C.sub.4 alkyl group, triglycerides, castor oil, ricinoleic acid, and ethoxylates of castor oil or ricinoleic acid, and mixtures thereof, the fluid comprising at most 3 wt.-% of an ester between boric acid and a glycol or alkylpolyglycol compound.

Claims

1. A functional fluid, comprising (A) from 70 to 90 wt.-% of alkoxy glycol according to formula (I)
CH.sub.3O(CH.sub.2CH.sub.2O).sub.nH(I) wherein n is a number from 2 to 5, with the proviso that in at least 30 wt.-% of all compounds according to formula (I) n is 3, and that 15 to 65 wt.-% of all compounds according to formula (I) have n=4 or 5, (B) less than 1.0 wt.-% of alkoxy glycol according to formula (II)
R.sub.1O(CH.sub.2CH.sub.2O).sub.mH(II) wherein R.sub.1 is a C.sub.2 to C.sub.8 alkyl residue, m is a number from 2 to 6, (C) from 8 to 25 wt.-% of at least one compound according to formula (III)
HO(CH.sub.2CH.sub.2O).sub.kH(III) wherein k is a number of 2 or higher, with the proviso that in at least 80 wt.-% of all compounds according to formula (III) k is 2 or 3, and (D) at least one additive, selected from the group consisting of corrosion inhibitors, alkalinity agents, aging protection agents, defoamers and lubricants, the lubricants being selected from the group consisting of propylene oxide containing alkylene oxide polymers that are optionally substituted with a C.sub.1 to C.sub.4 alkyl group, triglycerides, castor oil, ricinoleic acid, and ethoxylates of castor oil or ricinoleic acid, and mixtures thereof, and wherein the fluid comprises at most 3 wt.-% of an ester between boric acid and a glycol or alkylpolyglycol compound.

2. The functional fluid according to claim 1, wherein the components (A) to (D) add up to 100 wt.-%.

3. The functional fluid according to claim 1, wherein 30-85 wt.-% of all compounds according to formula (I) have n=3.

4. The functional fluid according to claim 1, wherein 18-62 wt.-% of all compounds according to formula (I) have n=4 or 5.

5. The functional fluid according to claim 1, wherein 2.5 wt.-% or less of all compounds according to formula (I) have n=2.

6. The functional fluid according to claim 1, wherein the content of component (A) in compounds according to formula (I) wherein n=1 is 1 wt.-% or less.

7. The functional fluid according to claim 1, wherein the content of component (A) in compounds according to formula (I) wherein n=6 or higher is 3 wt.-% or less.

8. The functional fluid according to claim 1, wherein the content in component (B) is at most 0.99 wt.-%.

9. The functional fluid according to claim 1, wherein R.sub.1 is C.sub.2 to C.sub.4 alkyl.

10. The functional fluid according to claim 1, wherein the content in component (B) is from 0.01 to 0.99 wt.-%.

11. The functional fluid according to claim 1, wherein the total amount of compounds according to formula (III), wherein k=2 is 1 to 15 wt.-% of the total fluid.

12. The functional fluid according to claim 1, wherein the total amount of compounds according to formula (III) wherein k=3 is 6 to 16 wt.-% of the total fluid.

13. The functional fluid according to claim 1, wherein the total amount of compounds according to formula (III) with k=4 or higher is 5 wt.-% or less of the total fluid.

14. The functional fluid according to claim 1, wherein the weight ratio between compounds according to formula (I) with n=3 and n=4 or higher is (n=3):(n=4, or higher)=1:2 to 6:1.

15. The functional fluid according to claim 1, wherein the weight ratio between component (A) and component (C) is (A):(C)=3:1 to 10:1.

16. The functional fluid according to claim 1, wherein component (D) is present in an amount of 0.4 to 6 wt.-%.

17. The functional fluid according to claim 1, wherein the corrosion inhibitor is selected from the group consisting of C.sub.8 to C.sub.22 fatty acids, esters of phosphorus or phosphoric acid with C.sub.1 to C.sub.18 aliphatic alcohols, phosphites having at least one C.sub.1 to C.sub.12 hydrocarbon residue; heterocyclic organic compounds having at least one nitrogen atom as heteroatom, and mixtures thereof.

18. The functional fluid according to claim 1, wherein the amine is selected from the group consisting of alkyl or cycloalkyl amines, alkanol amines, alkyl amine ethoxylates and their mixtures.

19. The functional fluid according to claim 1, wherein the stabilizer is selected from the group consisting of substituted phenols, sterically hindered amines and mixtures thereof.

20. The functional fluid according to claim 1, wherein the defoamer is selected from the group consisting of glycerides, waxes, fine powdered silica, ethylene oxide/propylene oxide block copolymers, silicone based defoamer and mixtures thereof.

21. The functional fluid according to claim 1, wherein the lubricant is selected from the group consisting of homopolymers of propylene oxide, copolymers of propylene oxide with ethylene oxide and/or butylene oxide, mono C.sub.1 to C.sub.4 alkyl substituted homopolymers of propylene oxide, mono C.sub.1 to C.sub.4 alkyl substituted copolymers of propylene oxide with ethylene oxide and/or butylene oxide, triglycerides, castor oil, ricinoleic acid, and ethoxylates of castor oil or ricinoleic acid, and mixtures thereof.

22. The functional fluid according to claim 1, comprising 0.3 to 3 wt.-% of an amine within the component (D), weight-% being relative to the fluid weight.

23. The functional fluid according to claim 1, wherein the fluid's content of in esters between boric acid and glycol or alkyl polyglycol compounds is less than 3 wt.-%.

24. The functional fluid according to claim 1, wherein the functional fluid has a kinematic viscosity of less than 800 centistokes at ?40? C., on an dry equilibrium reflux boiling point (ERBP) of at least 255? C. and a wet equilibrium reflux boiling point (WERBP) of at least 155? C., both ERBP and WERBP to be determined according to Federal Motor Vehicle Safety Standards (FMVSS) No 116.

25. A brake fluid comprising a functional fluid, wherein the functional fluid comprises (A) from 70 to 90 wt.-% of alkoxy glycol according to formula (I)
CH.sub.3O(CH.sub.2CH.sub.2O).sub.nH(I) wherein n is a number from 2 to 5, with the proviso that in at least 30 wt.-% of all compounds according to formula (I) n is 3, and that 15 to 65 wt.-% of all compounds according to formula (I) have n=4 or 5, and (B) less than 1.0 wt.-% of alkoxy glycol according to formula (II)
R.sub.1O(CH.sub.2CH.sub.2O).sub.mH(II) wherein R.sub.1 is a C.sub.2 to C.sub.8 alkyl residue, m is a number from 2 to 6, (C) from 8 to 25 wt.-% of at least one compound according to formula (III)
HO(CH.sub.2CH.sub.2O).sub.kH(III) wherein k is a number of 2 or higher, with the proviso that in at least 80 wt.-% of all compounds according to formula (III) k is 2 or 3, (D) at least one additive, selected from the group consisting of corrosion inhibitors, alkalinity agents, aging protection agents, defoamers and lubricants, the lubricants being selected from the group consisting of propylene oxide containing alkylene oxide polymers that are optionally substituted with a C.sub.1 to C.sub.4 alkyl group, triglycerides, castor oil, ricinoleic acid, and ethoxylates of castor oil or ricinoleic acid, and mixtures thereof, and wherein the fluid comprises at most 3 wt.-% of an ester between boric acid and a glycol or alkylpolyglycol compound.

26. A method of operating a vehicular brake, the method comprising transmitting hydraulic pressure by a functional fluid, wherein the functional fluid comprises (A) from 70 to 90 wt.-% of alkoxy glycol according to formula (I)
CH.sub.3O(CH.sub.2CH.sub.2O).sub.nH(I) wherein n is a number from 2 to 5, with the proviso that in at least 30 wt.-% of all compounds according to formula (I) n is 3, and that 15 to 65 wt.-% of all compounds according to formula (I) have n=4 or 5, and (B) less than 1.0 wt.-% of alkoxy glycol according to formula (II)
R.sub.1O(CH.sub.2CH.sub.2O).sub.mH(II) wherein R.sub.1 is a C.sub.2 to C.sub.8 alkyl residue, m is a number from 2 to 6, (C) from 8 to 25 wt.-% of at least one compound according to formula (III)
HO(CH.sub.2CH.sub.2O).sub.kH(III) wherein k is a number of 2 or higher, with the proviso that in at least 80 wt.-% of all compounds according to formula (III) k is 2 or 3, (D) at least one additive, selected from the group consisting of corrosion inhibitors, alkalinity agents, aging protection agents, defoamers and lubricants, the lubricants being selected from the group consisting of propylene oxide containing alkylene oxide polymers that are optionally substituted with a C.sub.1 to C.sub.4 alkyl group, triglycerides, castor oil, ricinoleic acid, and ethoxylates of castor oil or ricinoleic acid, and mixtures thereof, and wherein the fluid comprises at most 3 wt.-% of an ester between boric acid and a glycol or alkylpolyglycol compound.

Description

(1) According to the present invention, a functional fluid composition being essentially free from borates and butoxy glycols has been found which exhibits superior values of ERBP and of WERBP and for low temperature kinematic viscosity, while maintaining excellent resistance to corrosion, high stability and meeting other physical property requirements such as pH, reserve alkalinity and rubber swell. Especially very high WERBP values are achieved.

(2) In a first aspect, this invention relates to a functional fluid, comprising (A) from 70 to 90, preferably 75-87 wt.-% of alkoxy glycol according to formula (I)
CH.sub.3O(CH.sub.2CH.sub.2O).sub.nH(I) wherein n is a number from 2 to 5, with the proviso that in at least 30 wt.-% of all compounds according to formula (I) n is 3, and (B) less than 1.0 wt % of alkoxy glycol according to formula (II)
R.sub.1O(CH.sub.2CH.sub.2O).sub.mH(II) wherein R.sub.1 is a C.sub.2 to C.sub.8 alkyl residue, m is a number from 2 to 6, (C) from 8 to 25, preferably 12-23 wt.-% of at least one compound according to formula (III)
HO(CH.sub.2CH.sub.2O).sub.kH(III) wherein k is a number of 2 or higher, with the proviso that in at least 80 wt.-% of all compounds according to formula (III) k is 2 or 3, (D) from 0.4 to 6 wt.-% of at least one additive, selected from the group consisting of corrosion inhibitor, alkalinity agents, aging protection agents, defoamers and lubricants, the fluid comprising at most 3 wt.-% of an ester between boric acid and a glycol or polyglycol compound.

(3) In a second aspect, this invention provides the use of the functional fluid of the first aspect as a brake fluid for vehicular brakes.

(4) In a third aspect, this invention provides for a method of operating a vehicular brake that transmits braking force through a hydraulic system, the method comprising filling the hydraulic system with a functional fluid according to the first aspect.

(5) The functional fluid will be referred to as fluid in the following.

(6) Component (A) of the functional fluid according to this invention is a methyl-terminated polyglycol according to formula (I). Suitable compounds according to formula (I) comprise 2, 3, 4 or 5 ethoxy units. Compounds with a higher number of ethoxy units than 5, i.e. 6 ethoxy units or more, may be present but should be restricted to a content of 3 wt.-% at most, relative to the total weight of all compounds according to formula (I).

(7) The total amount of all compounds according to formula (I) in the fluid is from 70 to 90 wt.-%, relative to the weight of the fluid, preferably 75-87 wt.-%. The relative amount of any formula (I) component with n=2 preferably is not more than 2.5 wt.-%. The relative amount of any formula (I) component with n=3 is at least 32 wt.-%, preferably 35 to 85 wt.-%, more preferably 38-81 wt.-%. The relative amount of any formula (I) component with n=4 and 5 is preferably 15-65 wt.-%, more preferably 18-62 wt.-%. In component (A), species with n=1 are preferably not present in quantities higher than 1 wt.-%. In component (A), species with n=6 or higher are preferably not present in quantities higher than 3 wt.-%. All such relative amounts are relative to the total amount of formula (I) compounds, such total amount being 100 wt.-%.

(8) An increased amount of formula (I) components with n=4 or higher may rise the viscosity of the fluid.

(9) The functional fluid composition is free or essentially free of component (B). Essentially free means that component (B) is present in an amount that does not influence the application properties of the functional fluid composition as a brake fluid. It is assumed that a content of component (B) of less than 1.0 wt.-% does not influence such properties of the functional fluid composition. Component (B) of the functional fluid composition, according to formula (II), is present in an amount of less than 1.0 wt.-%, the total weight of the functional fluid composition being 100 wt.-%. Preferably, component (B) is present in an amount of 0 to 0.99 wt.-%.

(10) Another preferred range for the content of component (B) in the functional fluid composition is for example 0.01 to 0.99 wt.-%.

(11) Component (B) of the functional fluid composition, according to formula (II), comprises species of ethoxylation degrees of from m=2 to m=6, preferably of from m=2 to m=4. Component (B) may be a single species or a mixture of different species with regard to the ethoxylation degree and/or to radical R.sub.1. Radical R.sub.1 is preferably a C.sub.2- to C.sub.4-alkyl radical. R.sub.1 for example may be ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl. Ethyl, and especially butyl, are most preferred.

(12) Examples of alkoxy glycols making up component (B) of the present invention include ethyldiglycol, ethyltriglycol, ethyltetraglycol, ethylpentaglycol, ethylhexaglycol, n-propyldiglycol, n-propyltriglycol, n-propyltetraglycol, n-propylpentaglycol, n-propylhexaglycol, n-butyldiglycol, n-butyltriglycol, n-butyltetraglycol, n-butylpentaglycol, n-butylhexaglycol and mixtures thereof. For the avoidance of doubt, glycol always means ethylene glycol. Most important are butyltriglycol and butyltetraglycol.

(13) The component (B) may comprise a mixture of alkoxy glycols of general formula (II) comprising solely or predominantly species with m=3. Predominantly means that at least 65% by weight, more preferably at least 75% by weight, of component (B) comprises species with m=3. Species with m=4 are in one embodiment present in an amount of 10 wt.-% or more. Also, alkoxy glycol species with m=2 and/or m=5 and/or m=6 may be present in minor amounts. Species with m=2 are usually present in an amount not exceeding 3 wt.-%. Species with m=5, 6 or higher are usually present in an amount of less than 5 wt.-% in total. Weight percentages of species of component (B) are given in wt.-% with the total amount of component (B) being 100 wt.-%.

(14) Component (C) is a polyethylene glycol according to formula (III). In formula (III), k is a number of 2, or higher. It is preferred, that k is a number from 2-4. More preferably, k is 2 or 3. In one preferred embodiment, component (C) is a mixture of compounds according to formula (III) wherein k is 2 or 3.

(15) It is required that in at least 80 wt.-% of all compounds according to formula (III) k is 2 or 3, the wt.-% being relative to the total weight of all compounds according to formula (III). This means that compounds according to formula (III) wherein k is 2 or 3 make up 6.4 to 20 wt.-%, preferably 9.6 to 18.4 wt.-% of the fluid, the total fluid weight being 100 wt.-%.

(16) The total amount of component (C) in the fluid is from 8 to 25 wt.-%, preferably 12-23 wt.-% of the weight of the fluid, i.e. the total weight of the fluid being 100 wt.-%.

(17) In one preferred embodiment, the amount of species of formula (III) wherein k=2 is 6-12 wt.-%. In one other preferred embodiment, the amount of species of formula (III) wherein k=3 is 6-16 wt.-%. In one other preferred embodiment, the total amount of species according to formula (III) wherein k is 4 or higher than 4 is at most 10 wt.-%, more preferably at most 6 wt.-%. Said weight percentages provided for species according to formula (III) are provided as weight percentages of the fluid, i.e. the total weight of the fluid is 100 wt.-%. They are not provided as weight percentages of the total weight of component (C).

(18) Component (D) is an additive that is required to impart particular properties to the functional fluid for performing on specifications to be fulfilled for brake fluids according to the current norms and standards FMVSS, SAE J 1703 and ISO 4925. The total amount of all components (D) in the fluid is from 0.4 to 6 wt.-%, preferably from 0.5 to 5 wt.-%.

(19) Component (D) comprises one or more additives selected from the group consisting of corrosion inhibitors, amines as reserve alkalinity agents, stabilizing antioxidants, defoamers, lubricants and dyes.

(20) Component (D) may comprise an amine. Amines are preferably alkyl or cycloalkyl amines, alkanol amines, alkyl amine ethoxylates and their mixtures. Preferred alkyl amines are mono- and di-(C.sub.4- to C.sub.20-alkyl)amines. Examples of suitable alkyl or cycloalkyl amines are n-butylamine, n-hexylamine, n-octylamine, 2-ethylhexylamine, isononylamine, n-decylamine, n-dodecylamine, oleylamine, d-n-propylamine, di-isopropylamine, di-n-butylamine, tri-n-butylamine, di-n-amylamine, cyclohexylamine, and salts of such amines. Examples of suitable alkanolamines are mono-, di- and trimethanolamine, mono-, di- and triethanolamine, mono-, di- and tri-n-propanolamine and mono-, di- and tri-isopropanolamine. Examples of suitable alkyl amine ethoxylates are such linear or branched alkylamine ethoxylates carrying 1.5 to 5 EO moieties and an alkyl chain having 8 to 18 carbon atoms.

(21) Component (D) of the present functional fluid composition may comprise, besides the Amine, at least one additive with corrosion inhibition action, although the alkylamine ethoxylates exhibit corrosion inhibition properties themselves. Suitable customary additives with corrosion inhibition properties include fatty acids such as lauric, palm itic, stearic or oleic acid; esters of phosphorus or phosphoric acid with aliphatic alcohols or aliphatic alcohol ethoxylates; phosphites such as ethyl phosphate, dimethyl phosphate, isopropyl phosphate, n-butyl phosphate, triphenyl phosphite and diisopropyl phosphite; heterocyclic nitrogen containing organic compounds such as benzotriazole, tolyltriazole, 1,2,4-triazole, benzoimidazole, purine, adenine and derivatives of such heterocyclic organic compounds. Of course, mixtures of the above additives with corrosion inhibition action can be used.

(22) Defoamers may be selected from groups of oil based defoamers, such as natural oils, glycerides, waxes, fine powdered silica, alkoxylates such es EO/PO block copolymers, silicone based defoamers, preferably polyether modified or silicone derivatives and mixtures thereof.

(23) The fluid may include from 0 to 5% by weight, based on the total weight of the fluid, of a lubricant. Suitable lubricants are for example, propylene oxide containing alkylene oxide polymers that are optionally substituted with a C.sub.1 to C.sub.4 alkyl group, triglycerides, castor oil, ricinoleic acid, and ethoxylates of castor oil or ricinoleic acid and mixtures thereof. In a preferred embodiment, the lubricants are homopolymers of propylene oxide, copolymers of propylene oxide with ethylene oxide and/or butylene oxide, mono C.sub.1 to C.sub.4 alkyl substituted homopolymers of propylene oxide, mono C.sub.1 to C.sub.4 alkyl substituted copolymers of propylene oxide with ethylene oxide and/or butylene oxide, triglycerides, castor oil, ricinoleic acid, and ethoxylates of castor oil or ricinoleic acid and mixtures thereof. In case of such ethoxylates, 1 to 50 ethoxy units are preferred. In another preferred embodiment, the propylene oxide containing alkylene oxide polymers that are optionally substituted with a C.sub.1 to C.sub.4 alkyl group have a number average molecular weight in the range of 150 to 3000 g/mol.

(24) Suitable stabilizers or antioxidants are phenolic stabilizers like Bisphenols (e.g. Bisphenol A or Bisphenol M), butyl hydroxytoluene, methoxy phenols, butylated hydroxy anisole, hydroquinone derivatives; sterically hindered amines such as benzylated, alkylated or styrenated diphenylamine, styrenated phenylamine, substituted piperidine derivatives, phenothiazine derivatives or quinoline derivatives and mixtures thereof. In general, any literature known glycol stabilizing agents could be used herein.

(25) In one preferred embodiment, the % values (A)-(D) add up to 100% by weight.

(26) The total content of the fluid in boric acid esters is at most 3 wt.-%, preferably less than 0.3 wt.-%.

(27) In one preferred embodiment, the weight ratio between compounds according formula (I) with n=3 and n=4 or higher is (n=3):(n=4, or higher)=1:2 to 6:1.

(28) In one preferred embodiment, the weight ratio between component (A) and component (C) is (A):(C)=3:1 to 10:1.

(29) The functional fluid composition of the present invention exhibits superior behavior in ERBP and WERBP temperature and simultaneously in low temperature viscosity performance. It exhibits an ERBP of at least 255? C., more preferably of at least 260? C. and a WERBP of at least 155? C., more preferably at least 160? C. The functional fluid composition of the present invention exhibits a low temperature kinematic viscosity of less than 800 centistokes (cSt) (=mm.sup.2/s), more preferably of less than 750 cSt, each determined at a temperature of ?40? C. Selected examples of the functional fluid composition of the present invention may even meet the requirements of ISO 4925 class 6 brake fluids of ERBP min 250? C., WERBP of min 165? C. and a maximum viscosity at ?40? C. of 750 cSt. All analytical methods are described in FMVSS to which reference is made. For the purpose of this specification, ERBP and WERBP are to be determined according to FMVSS.

(30) The low viscosity functional fluid composition of the present invention is especially useful as a brake fluid, for example for vehicles such as passenger cars and trucks, especially for new electronic or automated anti-lock brake systems which require lower viscosity fluids for satisfactory operation at low temperatures.

(31) Besides its superior behavior in ERBP and WERBP temperature and its low temperature viscosity performance, the functional fluid composition of the present invention exhibits a good corrosion protection, a good water compatibility, a mild pH value, a good stability with regard to low and high temperatures, a good oxidation stability, a good chemical stability, a good behavior towards rubber and elastomers. a good lubrication performance and good foaming behavior.

EXAMPLES

(32) Table 1 shows functional fluid compositions and their performance. Numbers are provided in wt.-%, unless noted otherwise.

(33) TABLE-US-00002 TABLE 1 Example 1 Example 2 Example 3 Example 4 (?) (?) (?) (?) Component A 81.1385 79.2385 86.1685 75.9987 n = 3 31.1385 39.2385 51.1685 60.9987 n = 4 and 5 50 40 35 15 (>60% n = 4) Component B 0 0 0.98 0 (R.sub.1 = n-butyl) m = 3 0.98 m = 4 and higher (>80% m = 4) Component C 18 18 12 23 k = 2 (DEG) 10 9.5 6.6 9.5 k = 3 (TEG) 8 8.5 5.4 9.5 k = 4 and higher 4 Component D 0.8615 2.7615 0.8515 1.0013 Lubricant EO/PO random 0.1 0.15 copolymer mono butyl ether Castor Oil 1.5 ethoxylate (20 EO) Additives Diisopropanolamine 0.5 0.5 0.5 Octylamine + 2EO 1 Dibutylamine Defoamer 0.001 0.001 0.001 0.001 (polyether modified siloxane) Stabilizer BHT 0.2 0.2 Stabilizer 0.2 0.2 styrenated diphenylamine Stabilizer Bisphenol A Sodium nitrate Oleic acid 0.1 0.1 Phosphoric acid 0.06 0.06 0.05 0.05 ester dye stuff 0.0005 0.0005 0.0005 0.0003 Total 100 100 100 100 wERBP [? C.] 159 (?) 161 (?) 161 (?) 161 (?) ERBP [? C.] 267 (?) 263 (?) 261 (?) 258 (?) viscosity (?40? C.) 790 (?) 747 (?) 582 (?) 666 (?) [mm.sup.2/s] Component ratios Component A 0.62 0.98 1.46 4.07 n = 3/n = 4 or higher Component A:C 4.51 4.4 7.18 3.3 Comparative Comparative Comparative Comparative example 1 (?) example 2 (?) example 3 (?) example 4 (?) (EP-0129240 ex. 1) (Buty) (MTeG) (MTG) Component A 69.4 70.9385 80.9885 86.9885 n = 3 33.2 30.9385 25.9885 81.9885 n = 4 and 5 36.2 40 55 5 (>60% n = 4) Component B 0 10 0 0 (R.sub.1 = n-butyl) m = 3 7 m = 4 and higher 3 (>80% m = 4) Component C 30 18 18 12 k = 2 (DEG) 30 9.9 9.9 6.6 k = 3 (TEG) 8.1 8.1 5.4 k = 4 and higher Component D 0.6 1.0615 1.0115 1.0115 Lubricant EO/PO random 0.15 0.15 copolymer mono butyl ether Castor Oil ethoxylate (20 EO) Additives Diisopropanolamine 0.5 0.5 0.5 Octylamine + 2EO Dibutylamine 0.3 Defoamer 0.001 0.001 0.001 (polyether modified siloxane) Stabilizer BHT 0.2 0.2 Stabilizer 0.2 0.2 styrenated diphenylamine Stabilizer 0.28 Bisphenol A Sodium nitrate 0.02 Oleic acid 0.1 0.1 0.1 Phosphoric acid 0.06 0.06 0.06 ester dye stuff 0.0005 0.0005 0.0005 Total 100 100 100 100 wERBP [? C.] 160 (?) 157 (?) 159 (?) 154 (?) ERBP [? C.] 251 (?) 266 (?) 266 (?) 252 (?) viscosity (?40? C.) 1240 (?) 922 (?) 922 (?) 453 (?) [mm.sup.2/s] Component ratios Component A 0.92 0.77 0.47 16.4 n = 3/n = 4 or higher Component A:C 2.31 3.94 4.5 7.25 (?) = according to the present invention, or according to the required specification (?) = not according to the invention, or not according to the required specification