U.S. patent application number 10/496234 was filed with the patent office on 2005-01-27 for aqueous functional fluids with antioxidants.
Invention is credited to Evans, Samuel, Laeuger, Stefan, Rohrbach, Peter.
Application Number | 20050020457 10/496234 |
Document ID | / |
Family ID | 8184256 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050020457 |
Kind Code |
A1 |
Rohrbach, Peter ; et
al. |
January 27, 2005 |
Aqueous functional fluids with antioxidants
Abstract
The present invention relates to an aqueous functional fluid
comprising an antioxidant of the hindered phenol type and a
water-soluble polyalkylene glycol. The aqueous functional fluids
are especially suitable for use as hydraulic or metal working
fluids. The present invention also relates to the use of the
aqueous functional fluid for improving the performance properties
of hydraulic or metal working fluids.
Inventors: |
Rohrbach, Peter; (Liestal,
CH) ; Evans, Samuel; (Marly, CH) ; Laeuger,
Stefan; (Rheinfelden-Degerfelden, DE) |
Correspondence
Address: |
CIBA SPECIALTY CHEMICALS CORPORATION
PATENT DEPARTMENT
540 WHITE PLAINS RD
P O BOX 2005
TARRYTOWN
NY
10591-9005
US
|
Family ID: |
8184256 |
Appl. No.: |
10/496234 |
Filed: |
May 19, 2004 |
PCT Filed: |
November 13, 2002 |
PCT NO: |
PCT/EP02/12681 |
Current U.S.
Class: |
508/478 ;
508/501; 508/579 |
Current CPC
Class: |
C10M 169/04 20130101;
C10M 2209/1045 20130101; C10M 2207/289 20130101; C10M 2209/105
20130101; C10M 2209/104 20130101; C10M 173/02 20130101; C10N
2040/08 20130101; C10N 2030/64 20200501; C10M 2209/109 20130101;
C10N 2030/10 20130101; C10N 2040/20 20130101 |
Class at
Publication: |
508/478 ;
508/501; 508/579 |
International
Class: |
C10M 173/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 21, 2001 |
EP |
01811119.5 |
Claims
1. A functional fluid comprising a) A 4-hydroxyphenylpropionic acid
ester: 7wherein one of R.sub.1 and R.sub.2 represents hydrogen or
C.sub.1-C.sub.9alkyl; and the other one represents
C.sub.3-C.sub.9alkyl; R.sub.3 represents hydrogen or methyl;
R.sub.4 represents hydrogen, C.sub.1-C.sub.30alkyl,
(C.sub.1-C.sub.4alkyl).sub.1-3phenyl, phenyl or a group: 8wherein
R.sub.1' and R.sub.2' have the same meanings as R.sub.1 and R.sub.2
defined above; and n represents a numeral from 1 to 60; b) Water
soluble polyalkylene glycol or mixtures thereof; and c) Water.
2. A functional fluid according to claim 1 comprising as component
a) a 4-hydroxyphenylpropionic acid ester (I), wherein one of
R.sub.1 and R.sub.2 represents methyl; and the other one represents
tert-butyl; or both of R.sub.1 and R.sub.2 represent tert-butyl;
R.sub.3 represents hydrogen or methyl; R.sub.4 represents hydrogen,
C.sub.1-C.sub.9alkyl, or the group (A), wherein one of R.sub.1' and
R.sub.2' represents methyl; and the other one represents
tert-butyl; or both of R.sub.1' and R.sub.2' represent tert-butyl;
and n represents a numeral from 2 to 15.
3. A functional fluid according to claim 1 comprising as component
a) a 4-hydroxyphenylpropionic acid ester: 9wherein one of R.sub.1
and R.sub.2 represents methyl and the other one represents
tert-butyl; R.sub.1' and R.sub.2' are as defined as R.sub.1 and
R.sub.2; and the index n represents a numeral from 2 to 15; or
R.sub.1, R.sub.1', R.sub.2 and R.sub.2' represent tert-butyl; or
the index n represents a numeral from 2 to 15.
4. A functional fluid according to claim 1 comprising as component
a) a compound: 10
5. A functional fluid according to claim 3 comprising a) A
4-hydroxyphenylpropionic acid ester (I'); b) High viscosity, water
soluble polyalkylene glycol or mixtures thereof; c) Water; and,
optionally, d) Further additives suitable for aqueous hydraulic or
metal working fluids.
6. A concentrate comprising a) A 4-hydroxyphenylpropionic acid
ester (I), wherein R.sub.1-R.sub.4 and n are as defined in claim 1;
b) High viscosity, water soluble polyalkylene glycol or mixtures
thereof; and d) Further additives suitable for aqueous hydraulic or
metal working fluids.
7. A method for improving the performance properties of a
functional fluid which comprises adding to an aqueous phase a
4-hydroxyphenylpropionic acid ester (I), wherein R.sub.1-R.sub.4
and n are as defined in claim 1.
8. A method for improving the performance properties of a
functional fluid which comprises adding to an aqueous phase a
concentrate according to claim 6.
9. The use of an aqueous functional fluid according to claim 1 for
improving the performance properties of hydraulic or metal working
fluids.
Description
[0001] The invention relates to aqueous functional fluids
comprising 4-hydroxyphenylpropionic acid esters and water-soluble
polyalkylene glycols and to the use of these aqueous functional
fluids for improving the performance properties of metalworking
fluids or hydraulic fluids.
[0002] Additives are added to functional fluids, such as hydraulic
or metal working fluids, in order to improve the antioxidative
properties of the fluid or to comply with demanding technical and
ecological requirements, such as high load-carrying capacity or
protection against corrosion and wear. Zinc dialkyl
dithiophosphates are commonly used, but due to environmental
reasons, various attempts have been made to replace these compounds
with metal-free compounds. The use of metal-free hydraulic fluids
is mandatory, especially in agricultural machinery or generally in
mobile hydraulic units, where leakages present the ecological risk
of contamination of soil or water with zinc compounds. Therefore,
there is a need for metal-free and ashless additives. Suitable
hydraulic fluids should also comply with the specifications of the
leading hydraulic machine manufacturers, for example Denison HFO
(Denison Hydraulics) or Vickers M-2980-S (Vickers), and need to be
compatible with water. In addition, in accordance with the
specifications of DIN 51524 and Denison HFO, they should achieve a
failure load stage (FLS) of at least 10 in the FZG test.
[0003] U.S. Pat. No. 5,531,911 discloses zinc-free hydraulic fluids
based on oil that comprise phosphorus- and sulphur-containing
additive components. One component is a thiophosphoric acid ester
of the triphenylthiophosphate type, e.g. Irgalube.RTM. (trade mark
of Ciba Specialty Chemicals) TPPT. This component is combined with
dithiophosphoric acid esters of the IRGALUBE 63 type and with other
optional oil additive components, for example ammonium
sulphonates.
[0004] A disadvantage of oily formulations is their flammability,
especially at higher working temperatures of the machinery
employed. Fire resistant hydraulic fluids are mandatory in many
applications to minimise the problems associated with leaks of
hydraulic fluid from high pressure lines coming in contact with hot
equipment, e.g. welding machines, machine tools or die casting
machines in the automotive and steel industries.
[0005] Further disadvantages of oily formulations relate to the
high costs of waste disposal of used oily liquids and the lack of
compatibility with water. The contamination of hydraulic oils with
water occurs frequently, especially when mobile hydraulic units are
used. The presence of phosphorus and sulphur containing additives
causes hydrolytic degradation with subsequent formation of
corrosive decomposition products. They may attack the metals used
in the hydraulic units, e.g. steel and copper alloys, and cause
damage to hydraulic pumps. In addition, agglomerations of
decomposition products may also block the filters of by-pass
filtration units. It is known that the service life of hydraulic
units can be significantly extended by means of very fine
filtering. Therefore, the filter pore sizes of by-pass filtration
units have been reduced from 30.mu. to 6.mu.. Consequently, only
hydraulic oils that form only extremely small amounts of insoluble
hydrolytic decomposition products when contaminated with water can
efficiently be used.
[0006] Hydraulic fluids having water as a base are disclosed in
U.S. Pat. Nos. 4,151,059 and 4,138,346. While hydraulic fluids of
any type are primarily used to transmit forces, fluids additionally
have to provide lubrication of the mechanical parts of the
equipment in order to prevent excessive wear.
[0007] Driven by environmental, economic and safety aspects the use
of water based fluids, instead of neat oils, is also recommended
for quenching and cooling operations in metal working processes.
One type of fluids that satisfy these requirements is polyalkylene
glycols combined with water in various proportions. Due to the
relatively high temperatures involved in the quenching process, the
polyalkylene glycols are degraded by oxidation. To overcome this
problem, various antioxidants have been proposed.
[0008] According to U.S. Pat. No. 4,686,058 high viscosity water
hydraulic fluids are prepared by blending water, organic
thickeners, such as polyoxyalkylene polyols, and conventional
hydraulic fluid additives, such as hindered phenols.
[0009] The problem underlying the present invention is the
preparation of aqueous functional fluids useful as hydraulic or
metal working fluids that have improved compatibility with water
and a significantly lower tendency to form undesirable oxidation
and hydrolysis products.
[0010] It has surprisingly been found that the addition of a
suitable antioxidant of the hindered phenol type to an aqueous
fluid comprising water soluble polyalkylene glycol or mixtures
thereof produces compositions that meet the above-mentioned
specifications and have a significantly lower tendency to form
corrosive hydrolysis products.
[0011] Therefore, the present invention relates to a functional
fluid comprising
[0012] a) A 4-hydroxyphenylpropionic acid ester: 1
[0013] wherein
[0014] one of R.sub.1 and R.sub.2 represents hydrogen or
C.sub.1-C.sub.9alkyl; and the other one represents
C.sub.3-C.sub.9alkyl;
[0015] R.sub.3 represents hydrogen or methyl;
[0016] R.sub.4 represents hydrogen, C.sub.1-C.sub.30alkyl,
(C.sub.1-C.sub.4alkyl).sub.1-3phenyl, phenyl or the group: 2
[0017] wherein
[0018] R.sub.1' and R.sub.2' have the same meanings as R.sub.1 and
R.sub.2 defined above; and
[0019] n represents a numeral from 1 to 60;
[0020] b) Water soluble polyalkylene glycol or mixtures thereof;
and
[0021] c) Water.
[0022] The aqueous functional fluids are especially suitable for
use as hydraulic or metal working fluids. Therefore, the present
invention also relates to the use of the aqueous functional fluid
defined above for improving the performance properties of hydraulic
or metal working fluids.
[0023] These fluids are substantially ashless and metal free and
meet the above-mentioned specifications.
[0024] The terms and definitions used in the context of the
description of the present invention preferably have the following
meanings:
[0025] Component a)
[0026] In a compound (I) R.sub.1 and R.sub.2 defined as
C.sub.1-C.sub.9alkyl comprise unbranched and branched (where
possible) groups, for example methyl, ethyl, isopropyl, n-butyl,
isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, n-hexyl,
2-ethylbutyl, 1-methylpentyl, 1,3-dimethylbutyl, n-heptyl,
3-heptyl, 1-methylhexyl, isoheptyl, n-octyl, 2-ethylhexyl,
1,1,3,3-tetramethylbutyl, 1-methylheptyl, n-nonyl or
1,1,3-trimethylhexyl.
[0027] R.sub.1 and R.sub.2 defined as C.sub.3-C.sub.9alkyl
comprises unbranched and preferably branched groups, e.g.
isopropyl, isobutyl, tert-butyl, neopentyl, isopentyl,
2-ethylbutyl, 1-methylpentyl, 1,3-dimethyl-butyl, 3-heptyl,
1-methylhexyl, isoheptyl, 2-ethylhexyl, 1,1,3,3-tetramethylbutyl,
1-methylheptyl or 1,1,3-trimethylhexyl.
[0028] In a preferred embodiment of the invention one of R.sub.1
and R.sub.2 represents in a compound (I) hydrogen or
C.sub.1-C.sub.9alkyl, particularly methyl or tert-butyl, and the
other one represents C.sub.3-C.sub.9alkyl, particularly
tert-butyl.
[0029] R.sub.4 defined as C.sub.1-C.sub.30alkyl comprises
unbranched and branched (where possible) groups, for example
C.sub.1-C.sub.9alkyl with the above-mentioned meanings, or
C.sub.10-C.sub.30alkyl, particularly straight chain
C.sub.10-C.sub.30alkyl, e.g. n-decyl, n-dodecyl, n-tetradecyl,
n-hexadecyl or n-octadecyl or higher homologues thereof.
[0030] R.sub.4 defined as (C.sub.1-C.sub.4alkyl).sub.1-3phenyl
comprises phenyl that is substituted by 1 to 3 C.sub.1-C.sub.4alkyl
groups, e.g. methyl or tert-butyl.
[0031] In the group (A) R.sub.1' and R.sub.2' have the same
definitions as R.sub.1 and R.sub.2 defined above. In a preferred
embodiment of the invention one of R.sub.1' and R.sub.2' represents
in a group (A) hydrogen or
[0032] C.sub.1-C.sub.9alkyl, particularly methyl, and the other one
represents C.sub.3-C.sub.9alkyl, particularly tert-butyl. According
to another preferred embodiment of the invention both R.sub.1' and
R.sub.2' represent in a group (A) C.sub.3-C.sub.9alkyl,
particularly tert-butyl.
[0033] In a compound (I) the index n represents a numeral from 1
through 60 and defines the number of repeating units derived from
ethylene or propylene oxide or ethylene or propylene glycol. In a
preferred embodiment of the invention, n represents numerals from 2
to 20, particularly numerals from 2 to 15.
[0034] A preferred embodiment of the invention relates to an
aqueous functional fluid that comprises as component a) a
4-hydroxyphenylpropioni- c acid ester (I), wherein
[0035] one of R.sub.1 and R.sub.2 represents methyl; and the other
one represents tert-butyl; or
[0036] both of R.sub.1 and R.sub.2 represent tert-butyl;
[0037] R.sub.3 represents hydrogen or methyl;
[0038] R.sub.4 represents hydrogen, C.sub.1-C.sub.9alkyl, or the
group (A), wherein
[0039] one of R.sub.1' and R.sub.2' represents methyl; and the
other one represents tert-butyl; or
[0040] both of R.sub.1' and R.sub.2' represent tert-butyl; and
[0041] n represents a numeral from 2 to 15.
[0042] A particularly preferred embodiment of the invention relates
to an aqueous functional fluid that comprises as component a) a
compound: 3
[0043] wherein
[0044] one of R.sub.1 and R.sub.2 represents methyl and the other
one represents tert-butyl;
[0045] R.sub.1' and R.sub.2' are as defined as R.sub.1 and R.sub.2;
and the index n represents a numeral from 2 to 15;
[0046] or R.sub.1, R.sub.1', R.sub.2 and R.sub.2' represent
tert-butyl; and the index n represents a numeral from 2 to 15.
[0047] In a particularly preferred embodiment of the invention the
aqueous functional fluid comprises as component a) a compound:
4
[0048] The compounds (I) are known and can be produced by known
methods, such as the ones described in U.S. Pat. Nos. 4,032,562 and
5,696,281.
[0049] Component a) is present in the composition in an amount from
0.002 to 10.0%, preferably 0.002 to 5.0%, and most preferably 0.002
to 1.0%, based on the total weight of the composition.
[0050] Component a) is present in the concentrate described below
in an amount from 0.01 to 10.0%, preferably 0.02 to 5.0%, and most
preferably 0.01 to 2.0%, based on the total weight of the
composition.
[0051] Component b)
[0052] Polyalkylene glycol (polyalkylene oxides) or mixtures
thereof are derived from polyethylene glycol or polypropylene
glycol (=polyethylene oxide or polypropylene oxide) or mixed
polymerisates thereof and are represented by the formula 5
[0053] wherein n is a numeral from 1 to about 1.0.times.10.sup.6
and R.sub.a and R.sub.b represent hydrogen or methyl. Suitable
water soluble polyalkylene glycol (polyalkylene oxides) or mixtures
thereof are used as heat transfer fluids in the plastics industry
and in the reflowing of printed circuit boards at temperatures of
200.degree. C. to 240.degree. C. They show improved performance
over petroleum oils or non-aqueous solutions of polyethylene
glycols because of their good thermal and oxidative stability, good
heat transfer characteristics, high flash points, low tendency to
sludge formation, non staining behaviour or low pour point.
[0054] Particularly preferred are high viscosity polyalkylene
glycols that meet the following specifications:
[0055] Viscosity range according to ASTM D445 at 40.degree. C.
between 10 000 and 200 000 (cSt) and at 100.degree. C. between 1
000 and 180 000;
[0056] Pour point according to ASTM D97 between 0.degree. C. and
20.degree. C.;
[0057] Flash point (open cup) above 200.degree. C.;
[0058] Cloud point between 50-80.degree. C.
[0059] Suitable water-soluble polyalkylene glycols are commercially
available from ICI Corp. under the product name Emkarox.RTM.
(Trademark ICI Corp.), particularly the specific products EMKAROX
HV 19, 20, 26, 45, 105, 165.
[0060] Component b) is present in the composition in an amount from
0.5 to 95.0%, preferably 0.5 to 75.0%, and most preferably 0.1 to
50.0%, based on the total weight of the composition.
[0061] Component b) is present in the concentrate described below
in an amount from 5.0 to 95.0%, preferably 10.0 to 90.0%, and most
preferably 10.0 to 50.0%, based on the total weight of the
composition.
[0062] Component c)
[0063] The functional fluids contain about 60.0 to 99.0% water and
about 40.0 to 1.0% concentrate. Preferably, the fluids contain
about 75.0 to 99.0% water and about 25.0 to 1.0% concentrate. As a
means of reducing corrosion, the pH of the fluid is maintained
above 7. The fluids are easily formulated using tap water although
distilled or deionised water is preferred.
[0064] Component d)
[0065] The addition of at least one additional additive to the
functional fluid is optional but preferred.
[0066] Therefore, the invention also relates to an aqueous
functional fluid comprising
[0067] a) A 4-hydroxyphenylpropionic acid ester (I');
[0068] b) High viscosity, water soluble polyalkylene glycol or
mixtures thereof;
[0069] c) Water; and, optionally,
[0070] d) Further additives suitable for aqueous hydraulic or metal
working fluids.
[0071] The above-mentioned functional fluids, e.g. metal-working
fluids or hydraulic fluids, may additionally comprise further
additives that are added in order to improve their basic properties
still further. Such additives include: further antioxidants, metal
passivators, corrosion inhibitors, pour-point depressants,
dispersants, detergents, further extreme-pressure additives and
anti-wear additives. Such additives are added in the amounts
customary for each of them, which range in each case approximately
from 0.01 to 10.0%, preferably 0.1 to 1.0% by weight. Examples of
further additives are given below:
[0072] 1 Phenolic Antioxidants
[0073] 1.1 Alkylated Monophenols
[0074] 2,6-Di-tert-butyl-4-methylphenol,
2-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol,
2,6-di-tert-butyl-4-n-butylphenol,
2,6-di-tert-butyl-4-isobutylphenol,
2,6-dicyclopentyl-4-methylphenol,
2-(.alpha.-methylcyclohexyl)-4,6-dimethylphenol,
2,6-dioctadecyl-4-methyl- phenol, 2,4,6-tricyclohexylphenol,
2,6-di-tert-butyl-4-methoxymethylphenol- , linear nonylphenols or
nonylphenols branched in the side chain, such as
2,6-dinonyl-4-methylphenol,
2,4-dimethyl-6-(1'-methyl-undec-1'-yl)-phenol- ,
2,4-dimethyl-6-(1'-methylheptadec-1'-yl)-phenol,
2,4-dimethyl-6-(1'-meth- yltridec-1'-yl)-phenol and mixtures
thereof.
[0075] 1.2 Alkylthiomethylphenols
[0076] 2,4-Dioctylthiomethyl-6-tert-butylphenol,
2,4-dioctylthiomethyl-6-m- ethylphenol,
2,4-dioctylthiomethyl-6-ethylphenol, 2,6-didodecylthiomethyl--
4-nonylphenol.
[0077] 1.3 Hydroquinones and Alkylated Hydroquinones
[0078] 2,6-Di-tert-butyl-4-methoxyphenol,
2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone,
2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-tert-butylhydroquinone,
2,5-di-tert-butyl-4-hydroxyanisole,
3,5-di-tert-butyl-4-hydroxyanisole,
3,5-di-tert-butyl-4-hydroxyphenyl stearate,
bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate.
[0079] 1.4 Tocopherols
[0080] .alpha.-, .beta.-, .gamma.- or .delta.-Tocopherol and
mixtures thereof (vitamin E).
[0081] 1.5 Hydroxylated Thiodiphenyl Ethers
[0082] 2,2'-Thio-bis(6-tert-butyl-4-methylphenol),
2,2'-thio-bis(4-octylph- enol),
4,4'-thio-bis(6-tert-butyl-3-methylphenol),
4,4'-thio-bis(6-tert-bu- tyl-2-methylphenol),
4,4'-thio-bis(3,6-di-sec-amylphenol),
4,4'-bis(2,6-dimethyl-4-hydroxyphenyl)-disulphide.
[0083] 1.6 Alkylidene Bisphenols
[0084] 2,2'-Methylene-bis(6-tert-butyl-4-methylphenol),
2,2'-methylene-(6-tert-butyl-4-ethylphenol),
2,2'-methylene-bis[4-methyl-- 6-(.alpha.-methylcyclohexyl) phenol],
2,2'-methylene-bis(4-methyl-6-cycloh- exylphenol),
2,2'-methylene-bis(6-nonyl-4-methylphenol),
2,2'-methylene-bis(4,6-di-tert-butylphenol),
2,2'-ethylidenebis(4,6-di-te- rt-butylphenol),
2,2"-ethylidene-bis(6-tert-butyl-4-isobutylphenol),
2,2'-methylene-bis[6-(.alpha.-methylbenzyl)-4-nonylphenol],
2,2'-methylene-bis[6-(.alpha.,.alpha.-dimethylbenzyl)-4-nonylphenol],
4,4'-methylenebis(2,6-di-tert-butylphenol),
4,4'-methylene-bis(6-tert-but- yl-2-methylphenol),
1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,
2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,
1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,
1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane,
ethylene glycol
bis[3,3-bis(3'-tert-butyl-4'-hydroxyphenyl)butyrate],
bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene,
bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphe-
nyl]-terephthalate, 1,1-bis(3,5-dimethyl-2-hydroxyphenyl)butane,
2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane,
1,1,5,5-tetra(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.
[0085] 1.7 O-, N- and S-Benzyl Compounds
[0086] 3,5,3',5'-Tetra-tert-butyl-4,4'-dihydroxydibenzyl ether,
octadecyl-4-hydroxy-3,5-dimethylbenzyl-mercaptoacetate,
tridecyl-4-hydroxy-3,5-di-tert-butylbenzyl-mercaptoacetate,
tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine,
bis(4-tert-butyl-3-hydroxy-- 2,6-dimethylbenzyl)
dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybe- nzyl)
sulphide,
isooctyl-3,5-di-tert-butyl-4-hydroxybenzyl-mercaptoacetate- .
[0087] 1.8 Hydroxybenzylated Malonates
[0088] Dioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)
malonate, dioctadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)
malonate,
didodecylmercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)
malonate,
di-[4-(1,1,3,3-tetramethylbutyl)-phenyl]-2,2-bis(3,5-di-tert-bu-
tyl-4-hydroxybenzyl) malonate.
[0089] 1.9 Hydroxybenzyl Aromatic Compounds
[0090]
1,3,5-tris(3,5-Di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzen-
e,
1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,
2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.
[0091] 1.10 Triazine Compounds
2,4-bis-Octylmercapto-6-(3,5-di-tert-butyl--
4-hydroxyanilino)-1,3,5-triazine,
2-octylmercapto-4,6-bis(3,5-di-tert-buty-
l-4-hydroxyanilino)-1,3,5-triazine,
2-octylmercapto-4,6-bis-(3,5-di-tert-b-
utyl-4-hydroxyphenoxy)-1,3,5-triazine,
2,4,6-tris(3,5-di-tert-butyl-4-hydr- oxyphenoxy)-1,2,3-triazine,
1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate,
1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocya-
nurate,
2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,
1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-tr-
iazine,
1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.
[0092] 1.11 Acylaminophenols
[0093] 4-Hydroxylauric acid anilide, 4-hydroxystearic acid anilide,
N-(3,5-di-tert-butyl-4-hydroxyphenyl)-carbamic acid octyl ester.
1.12 Esters of .beta.-(5-tert-butyl-4-hydroxy-3-methylphenyl)
Propionic acid
[0094] With polyhydric alcohols, e.g. with 1,6-hexanediol,
1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol,
thiodiethylene glycol, diethylene glycol, triethylene glycol,
pentaerythritol, tris(hydroxyethyl)isocyanurate,
tris(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol,
3-thiapentadecanol, trimethylhexanediol, trimethylolpropane,
4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]o- ctane.
[0095] 1.13 Esters of .beta.-(3,5-di-tert-butyl-4-hydroxyphenyl)
propionic acid, .beta.-(3,5-dicyclohexyl-4-hydroxyphenyl) propionic
acid, 3,5-di-tert-butyl-4-hydroxyphenylacetic acid
[0096] With mono- or polyhydric alcohols, e.g. with methanol,
ethanol, n-octanol, isooctanol, octadecanol, 1,6-hexanediol,
1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol,
thiodiethylene glycol, diethylene glycol, triethylene glycol,
pentaerythritol, tris(hydroxyethyl)isocyanurate,
N,N'-bis-hydroxyethyl oxalic acid diamide, 3-thiaundecanol,
3-thiapentadecanol, trimethylhexanediol, trimethylolpropane,
4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]o- ctane.
[0097] 1.14 Amides of .beta.-(3,5-di-tert-butyl-4-hydroxyphenyl)
propionic acid
[0098] N,N'-bis(3,5-Di-tert-butyl-4-hydroxyphenylpropionyl)
hexamethylenediamine,
N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl- )
trimethylenediamine,
N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl-
)hydrazine.
[0099] 1.15 Ascorbic Acid (Vitamin C)
[0100] 1.16 Aminic Antioxidants
[0101] N,N'-Diisopropyl-p-phenylenediamine,
N,N'-di-sec-butyl-p-phenylened- iamine,
N,N'-bis-(1,4-dimethylpentyl)-p-phenylenediamine,
N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine,
N,N'-bis(1-methylheptyl)-p-phenylenediamine,
N,N'-dicyclohexyl-p-phenylen- e-diamine,
N,N'-diphenyl-p-phenylenediamine, N,N'-di-(naphth-2-yl)-p-pheny-
lenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine,
N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine,
N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine,
N-cyclohexyl-N'-phenyl-p- -phenylenediamine,
4-(p-tolueneonamido)-diphenylamine,
N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine,
N-allyldiphenylamine, 4-isopropoxydiphenylamine,
4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol,
4-dodecanoylaminophenol, 4-octadecanoylaminophenol,
di-(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomethyl
phenol, 2,4'-diaminodiphenylmetha- ne, 4,4'-diaminodiphenylmethane,
N,N,N',N'-tetramethyl-4,4'-diaminodipheny- lmethane,
1,2-di-[(2-methylphenyl)amino]ethane, 1,2-diphenylaminopropane,
o-tolylbiguanide, di-[4-(1',3'-dimethylbutyl)phenyl]amine,
tert-octylated N-phenyl-1-naphthylamine, mixture of mono- and
di-alkylated tert-butyl/tert-octyl-diphenylamines, mixture of mono-
and di-alkylated nonyldiphenylamines, mixture of mono- and
di-alkylated dodecyidiphenylamines, mixture of mono- and
di-alkylated isopropyl/isohexyl-diphenylamines, mixtures of mono-
and di-alkylated tert-butyldiphenylamines,
2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine,
mixture of mono- and di-alkylated tert-butyl/tert-octyl-ph-
enothiazines, mixtures of mono- and di-alkylated
tert-octylphenothiazines, N-allylphenothiazine,
N,N,N',N'-tetraphenyl-1,4-diaminobut-2-ene,
N,N-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine,
bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate,
2,2,6,6-tetramethylpiperi- din-4-one,
2,2,6,6-tetramethylpiperidin-4-ol.
[0102] 2 Further Antioxidants
[0103] Aliphatic or aromatic phosphites, esters of thiodipropionic
acid or thiodiacetic acid or salts of dithiocarbamic acid,
2,2,12,12-tetramethyl-5,9-dihydroxy-3,7,11-trithiatridecane and
2,2,15,15-tetramethyl-5,12-dihydroxy-3,7,10,14-tetrathiahexadecane.
[0104] 3 Metal Deactivators (e.g. for Copper)
[0105] 3.1 Benzotriazoles and Derivatives Thereof
[0106] 2-Mercaptobenzotriazole, 2,5-dimercaptobenzotriazole, 4- or
5-alkylbenzotriazoles (e.g. tolutriazole) and derivatives thereof,
4,5,6,7-tetrahydrobenzotriazole, 5,5'-methylene-bis-benzotriazole;
Mannich bases of benzotriazole or tolutriazole, such as
1-[di-(2-ethylhexyl)aminomethyl]tolutriazole and
1-[di-(2-ethylhexyl)amin- omethyl]benzotriazole;
alkoxyalkylbenzotriazoles, such as 1-(nonyloxymethyl)
benzotriazole, 1-(1-butoxyethyl)-benzotriazole and
1-(1-cyclohexyloxybutyl)-tolutriazole.
[0107] 3.2 1,2,4-Triazoles and Derivatives Thereof
[0108] 3-Alkyl- (or -aryl-) 1,2,4-triazoles, Mannich bases of
1,2,4-triazoles, such as
1-[di-(2-ethyl-hexyl)aminomethyl]-1,2,4-triazole- ;
alkoxyalkyl-1,2,4-triazoles, such as
1-(1-butoxyethyl)-1,2,4-triazole; acylated
3-amino-1,2,4-triazoles.
[0109] 3.3 Imidazole Derivatives
[0110] 4,4'-Methylene-bis(2-undecyl-5-methyl) imidazole and
bis[(N-methyl)imidazol-2-yl]-carbinol-octyl ether.
[0111] 3.4 Sulphur-Containing Heterocyclic Compounds
[0112] 2-Mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole,
2,5-dimercaptobenzothiadiazole and derivatives thereof;
3,5-bis[di-(2-ethylhexyl)aminomethyl]-1,3,4-thiadiazolin-2-one.
[0113] 3.5 Amino Compounds
[0114] Salicylidene-propylenediamine, salicylaminoguanidine and
salts thereof.
[0115] 4. Corrosion Inhibitors
[0116] 4.1 Organic acids, their esters, metal salts, amine salts
and anhydrides
[0117] Alkyl- and alkenyl-succinic acids and their partial esters
with alcohols, diols or hydroxycarboxylic acids, partial amides of
alkyl- and alkenyl-succinic acids, 4-nonylphenoxyacetic acid,
alkoxy- and alkoxyethoxy-carboxylic acids, such as dodecyloxyacetic
acid, dodecyloxy (ethoxy) acetic acid and amine salts thereof, and
also N-oleoyl-sarcosine, sorbitan monooleate, lead naphthenate,
alkenylsuccinic acid anhydrides, e.g. dodecenylsuccinic acid
anhydride, 2-(2-carboxyethyl)-1-dodecyl-3-methylglycerol and salts
thereof, especially sodium and potassium triethanolamine salts
thereof.
[0118] 4.2 Nitrogen-Containing Compounds
[0119] Tertiary aliphatic or cycloaliphatic amines and amine salts
of organic and inorganic acids, e.g. oil-soluble alkyl ammonium
carboxylates, and
1-[N,N-bis(2-hydroxyethyl)amino]-3-(4-nonylphenoxy)prop- an-2-ol;
heterocyclic compounds: substituted imidazolines and oxazolines,
e.g. 2-heptadecenyl-1-(2-hydroxyethyl)-imidazoline.
[0120] 4.3 Sulphur Containing Compounds
[0121] Barium dinonylnaphthalene sulphonates, calcium petroleum
sulphonates, alkylthio-substituted aliphatic carboxylic acids,
esters of aliphatic 2-sulphocarboxylic acids and salts thereof.
[0122] 5. Viscosity Index Enhancers
[0123] Polyacrylates, polymethacrylates,
vinylpyrrolidone/methacrylate copolymers, polyvinylpyrrolidones,
polybutenes, olefin copolymers, styrene/acrylate copolymers,
polyethers.
[0124] 6. Pour-Point Depressants
[0125] Poly(meth)acrylates, ethylene/vinyl acetate copolymers,
alkyl polystyrenes, fumarate copolymers, alkylated naphthalene
derivatives.
[0126] 7. Dispersants/Surfactants
[0127] Polybutenylsuccinic acid amides or imides, polybutenyl
phosphonic acid derivatives, basic magnesium, calcium and barium
sulphonates and phenolates.
[0128] 8. Extreme-Pressure and Anti-Wear Additives
[0129] Sulphur- and halogen-containing compounds, e.g. chlorinated
paraffins, sulphurised olefins or vegetable oils (soybean oil, rape
oil), alkyl- or aryl-di- or -tri-sulphides, benzotriazoles or
derivatives thereof, such as bis(2-ethylhexyl)-aminomethyl
tolutriazoles, dithiocarbamates, such as
methylene-bis-dibutyidithiocarbamate, derivatives of
2-mercaptobenzothiazole, such as 1-[N,N-bis(2-ethylhexyl)a-
minomethyl]-2-mercapto-1H-1,3-benzothiazole, derivatives of
2,5-dimercapto-1,3,4-thiadiazole, such as
2,5-bis(tert-nonyldithio)-1,3,4- -thiadiazole.
[0130] 9. Coefficient of Friction Reducers
[0131] Lard oil, oleic acid, tallow, rape-oil, sulphurised fats,
amides, and amines. Further examples are given in EP-A-0 565
487.
[0132] 10. Special Additives for Use in Water/Oil Metalworking
Fluids and Hydraulic Fluids
[0133] Emulsifiers, e.g. petroleum sulphonates, amines, such as
polyoxyethylated fatty amines, non-ionic surface-active substances;
buffers, e.g. alkanolamines; biocides, e.g. triazines,
thiazolinones, tris-nitromethane, morpholine, sodium pyridenethiol;
processing speed improvers, e.g. calcium and barium
sulphonates.
[0134] The above-mentioned components may be admixed with the
above-mentioned components a)-c) in a manner known per se according
to prior art methods for preparing hydraulic or metal working
fluids. It is also possible to prepare a concentrate or a so-called
"additive package" that can be diluted to give the working
concentrations for the intended lubricant.
[0135] Therefore, the invention also relates to a concentrate
comprising
[0136] a) A 4-hydroxyphenylpropionic acid ester (I), wherein
R.sub.1-R.sub.4 and n are as defined above;
[0137] b) A high viscosity, water soluble polyalkylene glycol or
mixtures thereof; and
[0138] c) The above-mentioned further additives suitable for
aqueous hydraulic or metal working fluids.
[0139] The concentrates of the aqueous functional fluids can be
made up free of water or contain any desired amount of water, but
preferably contain up to 85% by weight of water to increase
fluidity and provide ease of blending at the point of use. As
pointed out above, these concentrates are diluted with water in the
proportion of 1.0:99.0% to 40.0:60.0% to make up the final
hydraulic or metal working fluid.
[0140] The aqueous functional fluids according to the present
invention are transparent liquids being stable over long periods of
storage and ambient temperature. In addition, the aqueous
functional fluids are oil-free, do not support combustion, are
ecologically clean and non-polluting as compared with existing
functional fluids based on oil.
[0141] Another embodiment of the invention relates to a method for
improving the performance properties of an aqueous functional fluid
which comprises adding to an aqueous phase a
4-hydroxyphenylpropionic acid ester (I), wherein R.sub.1-R.sub.4
and n are as defined above.
[0142] The examples are intended for the purpose of illustration.
Throughout the application, all parts, proportions and percentages
are by weight and all temperatures are in degrees centigrade unless
otherwise noted.
EXAMPLES
[0143] Stabilisation of hydraulic and metal working fluids with
selected 4-hydroxyphenylpropionic acid esters
[0144] a) Materials and Methods
[0145] Induction Temperature Measured Under PDSC Conditions
[0146] PDSC Test Conditions
1 DSC cell METTLER DSC27HP Pan Seiko Instrument Open Sample Pan
diameter 5 mm, aluminium Method Dynamic method Start temperature
50.degree. C. Heating rate 5.degree. C./min End temperature
250.degree. C. Sample size 2.7 +/- 0.1 mg Gas Oxygen 50 ml/min, 1
MPa (10 bar)
[0147] Test Compounds 6
[0148] b) Results
2TABLE Demln Test Test Induction Example EMKAROX Water Compound 1
Compound 2 Temperature No. HV45 [%] [%] [%] [%] Aspect [.degree.
C.] 1 80.0 20.0 -- -- -- 146.9 2 79.2 19.8 1.0 -- -- 172.7 3 79.2
19.8 -- 1.0 Clear thick 158.19 liquid 4 60.0 40.0 -- -- -- 137.9 5
59.4 39.6 1.0 -- -- 177.8 6 50.0 50.0 -- -- -- 143.2 7 49.5 49.5
1.0 -- -- 177.9 8 40.0 60.0 -- -- -- 140.3 9 39.6 59.4 1.0 -- --
180.2 10 20.0 80.0 -- -- -- 135.9 11 19.8 79.2 1.0 -- -- 193.2 12
19.8 79.2 -- 1.0 Hazy 165.01 13 19.8 80.0 0.2 -- Completely 182.14
clear Overall concentration of Test Compound 1 = 0.2 weight %
* * * * *