JPS6046155B2 - hydraulic oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to hydraulic fluids, and more particularly to hydraulic fluids containing certain silane derivatives.

Hydraulic oils based on glycol ether have been used in automobile brake and clutch systems for many years and are the most widely used.

However, hydraulic manufacturers and The Society
Of Automotive Engineers (TheSO
societyOfAutOmOtiveEngineer
s), U●S●Department●of●Transportation (U.S.DepartmentOfTr
The quality standards set by public institutions such as AnspOrtatiOn) are becoming increasingly strict. In particular, there is an increasing demand for higher boiling point hydraulic fluids and, more importantly, higher vapor lock, both for hydraulic fluids formulated by the manufacturer and for fluids that are also used in the presence of water. temperature is required. Glycol ether based oils are known to absorb moisture from the atmosphere due to their hygroscopic nature and are therefore unsuitable for such requirements. The absorption of water lowers the boiling point and vapor lock temperature of the hydraulic fluid, and with use, the water content of the hydraulic fluid reaches such a level that its boiling point and vapor lock temperature drop to a dangerous level. If it encounters the heat generated when applying strong brakes, the hydraulic fluid boils or vaporizes, causing significant brake malfunction.
In order to solve this problem, low hygroscopic hydraulic fluids based on glycol esters have also been developed.

Although this fluid is relatively insensitive to atmospheric moisture, it is more expensive than glycol ether-based oils and has technical drawbacks, such as its viscosity characteristics that differ from glycol ether-based oils. is inferior to
Therefore, the use of such low hygroscopic oils is limited to cases where the desired high boiling point, high vapor lock temperature, etc. properties outweigh their disadvantages. Other moisture-insensitive hydraulic fluids have also been developed. However, manufacturers are seeking new hydraulic oils that combine the good properties of both glycol ether-based oils and low hygroscopic oils, yet have even higher boiling points and vapor lock temperatures than the low hygroscopic oils. Recently, the power steering and shock absorbers, which were operated by separate hydraulic systems,
There is a tendency to design cars in which brakes and other functions are operated by a single hydraulic system.

This has important implications for the formulation of suitable hydraulic fluids. Mineral oil-based oils, which have been used in power steering systems and shock absorbers, can be used satisfactorily in the nitrile rubber and chloropropylene rubber used in seals and gaskets of these systems, but they have not been used in hydraulic brakes and clutch systems. It is extremely harmful to natural rubber, styrene/butadiene rubber, etc. As a result, the latter seal expands abnormally, resulting in severe malfunction of the brake and clutch systems. Therefore, hydraulic oils based on glycols, glycol ethers, and glycol ether esters, which have been widely used in brake and clutch systems, have been replaced by nitrile rubber and chloroprene rubber used in power steering and shock absorbers. Harmful, leading to malfunction of those systems. In vehicle operation, reliability of operation (which is desirable in all mechanical devices) is considered more important as an essential condition from the viewpoint of safety. Therefore, this request
It is also given to hydraulic fluids that can be used satisfactorily in central systems that control the operation of various devices. The inventors have discovered that certain silicon compounds are useful as components of hydraulic fluids used in hydraulic brakes, clutch systems, and central hydraulic systems. These compounds improve the swelling properties of various natural and synthetic rubbers used in hydraulic structures and are relatively water-insensitive.
The compound has the formula [wherein (a) R is a group represented by R4-(0R5)n1-0R6-; (b) R1 and R2 are each lower alkyl, -0R
3 or a group represented by R4-(0R5)m-0R6-;
(c) R3 is the same or different and R4-(0R5)
．． A group represented by n-; (d) R4 is the same or different and is alkyl having 1 to 18 carbon atoms; (e) R5 is the same or different and is ethylene or propylene; (f) R6
are the same or different alkylene having up to 6 carbon atoms;
(g) m is the same or different and is a silane derivative represented by 0 or an integer of 1 to 4;

The silane derivative of formula (1) in which m is other than 0 is a new compound. When this silane derivative is used in hydraulic brake and clutch systems, the terminal alkyl group must have a relatively short chain, e.g. 1-4
, more preferably 1 or 2 alkyl.
However, when used in central systems, there are often competing requirements for each type of seal and gasket.
It is desirable to meet the requirements. In this case, some or all of the terminal alkyl groups may be replaced with longer chain alkyl groups,
For example, it may have up to 6 carbon atoms, sometimes as many as 8 carbon atoms. Furthermore, in mineral oil-based hydraulic fluids, longer chain terminal alkyl groups, e.g.
From the viewpoint of oil solubility, it is necessary to use 18 caps, sometimes 18 caps. The terminal alkyl group may be either straight chain or branched, but branched alkyl is preferred from the viewpoint of oil solubility (particularly in mineral oil). The silane derivatives of the present invention are easily produced from appropriate haloalkylsilanes by known methods.

The silane derivatives are used as additives in hydraulic fluids, base oils or as a component of base oil mixtures. The dosage ranges over a wide range, from 0.5 to 99% (based on the total amount of hydraulic fluid).
% by weight, hereinafter the same). When used as a base oil, this silane derivative becomes the main constituent of the hydraulic fluid and, based on its total weight, for example 75 or 80
Included within 99% of the range. The remainder is known hydraulic fluid additives and/or other hydraulic fluid base oils. When used as a component of a base oil mixture, the entire base oil mixture becomes the main component of the hydraulic fluid, in which case the base oil consists primarily of one or more silane derivatives;
A smaller amount of one or more other base oils is added to this to modify the properties of the silane derivative.

The hydraulic fluid thus contains, for example, 55-75%, based on the total weight, of one or more silane derivatives. - Smaller amounts of silane derivatives may also be mixed in to modify the properties of one or more other base oils, in which case the hydraulic oil contains, for example, 20 to 40% of silane derivatives.
Furthermore, in order to balance the properties of the silane derivative and other base oils, they may be mixed in approximately equal amounts so that the silane derivative content is 40 to 55%. Also,
When used to reduce the sensitivity of hydraulic fluids to water, especially with regard to their boiling point and vapor lock temperature, the silane derivatives may be present in an amount of 20 to 50%, more preferably 20%.
It is desirable to use it in the range of ~40%.

Additionally, smaller amounts, such as 0.5-15% or 2
Although there is an improvement effect even if silane derivatives are used up to 0%,
The higher doses mentioned above are more preferred. The main component of the hydraulic oil in this case is one or more of the other base oils described below. When a silane derivative is used as one component of a base oil mixture, known hydraulic oil additives may be added, as in the case of a base oil consisting essentially of a silane derivative. Similarly, when used as additives, silane derivatives may be used in combination with other known hydraulic fluid additives, if desired. Known additives are usually used in small amounts in the range 0.05-10%, for example 0.1-2%.

Base oils which can be mixed with silane derivatives or can be formulated with silane derivatives as additives include mineral oils, polyoxyalkylene glycols and their ethers, alkyl and polyoxyalkylene mono-, di- or polycarboxylic acids or boric acids. Included are glycol ether esters, formals, acetals, phosphate esters, silicones, monocarboxylic acid esters of di- or polyalcohols, and other known base oils.

In one preferred embodiment of the present invention, the formula (1)
5 to 30% of at least one silane derivative of the following formula Rl
l-Si--0R12, R11-Si-0R12 again?
Ma people Pl2 big! ? 12 [In the formula, Rll is alkyl (
(preferably alkyl having 1 to 18 carbon atoms) or aryl (preferably phenyl): Rl2 is alkyl (preferably alkyl having 1 to 18 carbon atoms), aryl (preferably phenyl), alkaryl (preferably 1 to 12 carbon atoms);
phenyl substituted with alkyl), aralkyl (preferably benzyl) or R4-(0R5). A group represented by n-; Rl3 is an alkyl group (preferably a group having 1 to 18 carbon atoms)
alkyl), aryl (preferably phenyl), alkaryl (preferably phenyl substituted with alkyl having 1 to 12 carbon atoms), aralkyl (preferably benzyl)
or a group represented by R4-(0R5)m-0-; R4,
A hydraulic oil is provided in which 5 to 30% of at least one of the known base oil compounds represented by R5 and m are the same as defined for formula (1) above is blended with a glycol ether base oil.

In yet another preferred embodiment, substantially the formula (1)
10-90% of at least one silane derivative of the formula (■
), (■) or (■) 90
Provide a hydraulic oil consisting of ~10%.

In either composition, the hydraulic oil of the present invention is
The kinematic viscosity at is 5000:) Sζ especially 2000:)
It is desirable not to exceed St. Furthermore, it is preferred that the hydraulic oil of the present invention has a boiling point of at least 260°C.
In yet another aspect of the present invention, there is provided a hydraulic system for transmitting power by hydraulic means, which includes the above-mentioned hydraulic fluid as a functional fluid.

In yet another aspect, there is provided a method for operating a hydraulic system, which comprises introducing the above-mentioned hydraulic oil into the hydraulic system, applying pressure to the hydraulic oil, and transmitting power.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 In a glass flask with a 1 foot packed column,
Tris(methoxy)-3-chloropropylsilane 794
y (4 mol) and methyl triglycol 2296y (14
188.1 mol) of methanol from the mixture.
Heat under nitrogen atmosphere until g is removed.

The column was removed and heating was continued at a minimum temperature of 200° C. to obtain 317.4y (theoretical value: 384f) of the reactant. Dissolve 101.2 g (4.4 gram atoms) of sodium in 1000 y (6.1 mol) of methyl triglycol,
After adding the obtained slurry to the above reaction mixture, 10
Hold at 0°C for 3 hours.

The product was collected and the minimum temperature was 180℃, 0.17177!
Distill with Hg and filter again. Si content 4.20% [
A dark liquid with theoretical Si content of tris(methyltriglycol)-3-methyltriglycolpropylsilane: 3.88% is obtained. This product has a boiling point of 320°C and a viscosity of (-
40℃) 2306CS. This thing is SBR-
G9 (4.2%) and Natural R32 (-1.0%
) was tested for rubber expansibility, and good results were obtained. Example 2 Tris(methoxy)-3-chloropropylsilane 198.5y (1 mol), methyldiglycol 396y (3.3 mol) and sodium 25f (
400 g (1.1 g atom) of methyl diglycol (3
．． Tris(methyldiglycol)-3-methyldiglycolpnolopylsilane is obtained using a slurry in 4 mol).

77 g of methanol (theoretical: 96 g) are collected in the first step.

A product 409y (75%) is obtained with a Si content of 6.092% (theoretical value: 5.12%) and a chlorine content of 0.2%. This product has a viscosity (-40°C) of 1051 CS1 and a boiling point of 310
°C, SBRG9 (8.9%) and Natural R
32 (2.0%) gave good results in the rubber expansivity test. Example 3 In the same manner as above, 3-chloropropyltrimethoxysilane 397y (2 mol), tridecanol 1400f
Tris(tridecanoxy)-3-tridecanoxypropyl using a slurry of 1 (7 moles), 0.2y p-toluenesulfonic acid and 50.6y (2.2 gram atoms) of sodium in 800ml (4 moles) of tridecanol. Take silane.

168y (theoretical amount: 192y) of methanol is obtained.
Product 7 with Si content 3.46% (theoretical value: 3.23%)
11f (82%) is obtained. A blend of this product (50%) and DTD585 mineral oil (50%) has a viscosity (-
The vapor lock temperature was 225°C after heating it with 0.5% H2O at 100°C for n hours.

Examples 4-26 Hydraulic oils of the present invention were subjected to the following tests.

(a) Kinematic viscosity (-400C) in centistokes (CS)
It was measured by the method described in the SAEl7O3C' specifications.

(b) Rubber expansibility was determined by styrene/butadiene rubber (SBR).
), nitrile rubber and ethylene/propylene rubber.

In the case of SBR, it was performed using a standard SAESBR cup as described in the FMVSSll6DOT3/4 specification. For the rubber expansibility of nitrile rubber, use a nitrile rubber test piece (2.54d square, 2? thickness) as a test liquid! 5
It was determined by the increase in capacity when held at 120°C in 0ml for 7 hours. Regarding ethylene/propylene rubber, ethylene/propylene rubber such as that used in the aircraft industry
The same procedure as in the case of nitrile rubber was carried out in Step 5 except that a propylene rubber ring gel was used. (c) Vapor lock temperature was measured after subjecting the test liquid to a humidity test as described in the FMVSSII Annex (without using a control liquid).

For hydraulic fluids consisting of glycol ether base oils, SAE Jl7O5ft for silicone brake fluids
The Markey Vapor Lock test is performed using the equipment and method described in the specification.
The vapor lock temperature was measured by r'LOckTest). The vapor lock temperature of non-glycol ether-based oils is determined by the Gilpin Vapor Lock Test (Gilp
inVapOurOckTest).

The Gilpin vapor lock temperature is the temperature at which bubbles 3r1LL occur. (d) Hydrolytic stability was measured as follows.

That is, add 10% water to the test solution, and add 10% water in a sealed ampoule.
After heating at 00° C. for 24 hours, the mixture was cooled and the appearance of gelation or separation was checked. Expression (■), (■) or (
(2) Silane alone or a mixture thereof with a glycol ether base oil generally gels under such conditions. These results are shown in Tables 1 to 3.

The abbreviations and commercially available products in the table mean the following. Butyl monoglycol diethylene glycol monobutyl ether DPM: Dipropylene glycol monomethyl ether MTG: Triethylene glycol monomethyl ether MDG: Diethylene glycol monomethyl ether Mineral oil A: Naphthenic acid mineral oil, viscosity: 130CS (-40°F)
), 3.5CS (100°F), 1.31CS (210
'F); Pour point: 〉-705F; Boiling point: 248FC; Flash point: 208℃; Aniline point: 76FC Mineral oil D: Ditridecyl dodecanedioate refrigerant oil B: Commercially available refrigerant oil (B
ZERICES53 made by ritishPetrOIeum
), considered to be a mixture of alkylated benzenes.

Refrigerant oil C: 1 product of naphthenic acid mineral oil, relative density: 0.9
20; viscosity 63. CCS (100°F), 6.1CS (
210°F); Flash point: 183°C; Pour point: -36°C Silicone oil: Commercially available silicone brake oil (DOwCO
ming 02-1062) E555: Commercially available ethylene/propylene glycol ether (Dow Chemical
alCO. Co., Ltd.), molecular weight: approximately 243; the terminal ether alkyl group is thought to be mainly methyl, but a portion is thought to be ethyl.

A79 Nitrile Rubber A commercially available nitrile rubber used in Girling brake systems.

Claims (1)

[Claims] 1 Formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) [In the formula, R
is a group represented by R^4-(OR^5)_m-OR^6-; R^1 and R^2 are each lower alkyl, -OR^3
or a group represented by R^4-(OR^5)_mOR^6-; R^3 is the same or different and R^4-(OR^5)_mOR^6-;
5) Group represented by _m-; R^4 is the same or different alkyl having 1 to 18 carbon atoms; R^5 is the same or different and ethylene or propylene; R^6 is the same or different , alkylene having up to 6 carbon atoms; m is the same or different and means 0 or an integer from 1 to 4]
A hydraulic fluid containing 0.5 to 99% by weight of at least one silane derivative represented by the following formula based on the total amount. 2. Hydraulic oil according to claim 1, containing at least one known hydraulic oil additive and/or base oil. 3 5-30% by weight of at least one of the compound (I)
and formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II), ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IV) [In the formula, R^1 ^1 is alkyl or aryl; R^1^2 is alkyl, aryl, alkaryl, aralkyl or R^4-(OR^
5) Group represented by __m-; R^1^3 is alkyl, aryl, alkaryl, aralkyl or R^4-(OR
^5) _m-O- group; R^4, R^5 and m are the same as described in claim 1] 5 to 30% by weight of at least one compound represented by the group represented by _m-O- is a glycol ether. The hydraulic oil according to claim 1, which is blended with base oil. 4. Operation according to claim 3, consisting of 10 to 90% by weight of at least one compound (I) and 90 to 10% by weight of at least one compound of formula (II), (III) or (IV). oil.