U.S. patent application number 10/477251 was filed with the patent office on 2004-10-28 for lubricating oil composition comprising an additive combination of a carboxylic acid and an amine as ant-rust agent.
Invention is credited to Baba, Yoshiharu.
Application Number | 20040214733 10/477251 |
Document ID | / |
Family ID | 18988568 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040214733 |
Kind Code |
A1 |
Baba, Yoshiharu |
October 28, 2004 |
Lubricating oil composition comprising an additive combination of a
carboxylic acid and an amine as ant-rust agent
Abstract
A lubricating oil composition is provided containing a major
amount of a lubricating oil base oil and a minor amount of an
additive combination containing (i) a carboxylic acid-based or
carboxylic acid ester based anti-rust agent; (ii) at least one type
of amine selected from among the group comprising (A) the alkyl
amines which can be represented by general formula (1)
(R.sup.1).sub.nNH.sub.3-n (1) wherein R.sup.1 represents a
saturated or unsaturated alkyl group which has from 12 to 30 carbon
atoms, and n is an integer of value 1 or 2; and (B) the
N-alkylpolyalkylenediamines which can be represented by general
formula (2) R.sup.2NH(CH.sub.2).sub.mNH.sub.2 (2) wherein R.sup.2
represents a saturated or unsaturated alkyl group which has from 12
to 30 carbon atoms, and m is an integer of value from 2 to 5.
Inventors: |
Baba, Yoshiharu; (Kanagawa,
JP) |
Correspondence
Address: |
Yukiko Iwata
Shell Oil Company
Intellectual Property
PO Box 2463
Houston
TX
77252-2463
US
|
Family ID: |
18988568 |
Appl. No.: |
10/477251 |
Filed: |
June 1, 2004 |
PCT Filed: |
May 7, 2002 |
PCT NO: |
PCT/EP02/05066 |
Current U.S.
Class: |
508/430 ;
508/433; 508/436; 508/545; 508/558 |
Current CPC
Class: |
C10M 129/40 20130101;
C10M 2223/047 20130101; C10M 137/04 20130101; C10M 2207/146
20130101; C10N 2030/12 20130101; C10M 141/10 20130101; C10M
2207/287 20130101; C10M 2207/16 20130101; C10M 2207/027 20130101;
C10M 2215/22 20130101; C10M 2207/125 20130101; C10M 2215/082
20130101; C10M 2219/10 20130101; C10M 2223/042 20130101; C10M
2223/10 20130101; C10M 2215/26 20130101; C10M 129/76 20130101; C10M
2215/062 20130101; C10M 2223/04 20130101; C10M 2207/262 20130101;
C10M 2219/085 20130101; C10N 2040/046 20200501; C10M 133/16
20130101; C10M 137/02 20130101; C10M 2223/049 20130101; C10M
2215/12 20130101; C10N 2040/044 20200501; C10M 137/105 20130101;
C10M 2215/064 20130101; C10M 2215/28 20130101; C10M 2203/10
20130101; C10M 2215/122 20130101; C10M 2219/106 20130101; C10M
2207/288 20130101; C10N 2040/04 20130101; C10M 2207/026 20130101;
C10M 2215/066 20130101; C10M 2219/108 20130101; C10M 135/26
20130101; C10M 2203/102 20130101; C10M 2215/225 20130101; C10M
2223/041 20130101; C10M 129/58 20130101; C10M 2207/124 20130101;
C10M 2215/30 20130101; C10M 2215/226 20130101; C10M 2205/02
20130101; C10M 2207/289 20130101; C10M 129/36 20130101; C10M
2219/102 20130101; C10N 2040/042 20200501; C10M 2207/144 20130101;
C10M 2207/129 20130101; C10M 2215/065 20130101; C10M 2215/08
20130101; C10M 2219/104 20130101; C10M 2229/041 20130101; C10M
2207/024 20130101; C10M 2207/126 20130101; C10M 2215/04 20130101;
C10N 2040/08 20130101; C10M 2223/02 20130101; C10M 2215/221
20130101; C10M 2219/044 20130101; C10M 2219/046 20130101; C10M
2207/028 20130101; C10M 2215/086 20130101 |
Class at
Publication: |
508/430 ;
508/433; 508/436; 508/545; 508/558 |
International
Class: |
C10M 141/00; C10M
141/06 |
Foreign Application Data
Date |
Code |
Application Number |
May 11, 2001 |
JP |
2001-142228 |
Claims
1. A lubricating oil composition comprising a minor amount of an
additive combination comprising (i) a carboxylic acid-based or
carboxylic acid ester-based anti-rust agent; (ii) at least one type
of amine selected from the group consisting of (A) alkyl amines
which can be represented by general formula
(1),(R.sup.1).sub.nNH.sub.3-n (1)wherein R.sup.1 represents a
saturated or unsaturated alkyl group which has from 12 to 30 carbon
atoms, and n is an integer of value 1 or 2; and (B)
N-alkylpolyalkylenediamines which can be represented by general
formula (2),R.sup.2NH(CH.sub.2).sub.mNH.sub.2 (2)wherein R.sup.2
represents a saturated or unsaturated alkyl group which has from 12
to 30 carbon atoms, and m is an integer of value from 2 to 5; and a
major amount of a lubricating oil base oil, wherein said
composition comprises from 0.001 to 0.5 part by weight of the
carboxylic acid-based or carboxylic acid ester-based anti-rust
agent; and from 0.001 to 0.05 part by weight of the at least one
type of amine, per 100 parts by weight of lubricating oil base
oil.
2. The lubricating oil composition of claim 1 wherein said
composition comprises from 0.001 to 0.05 part by weight of the
carboxylic acid-based or carboxylic acid ester-based anti-rust
agent, per 100 parts by weight of lubricating oil base oil.
3. The lubricating oil composition of claim 1, which further
comprises, as an extreme pressure additive, at least one compounds
selected from .beta.-dithiophosphorylpropionic acids which can be
represented by general formula
(3),S.dbd.P(--O--R.sup.3).sub.2SCH.sub.2CH(R.sup.4)COOH (3)wherein
R.sup.3 represents a branched alkyl group which has from 3 to 8
carbon atoms, and R.sup.4 is a hydrogen atom or a group selected
from among the linear chain or branched alkyl groups which have
from 1 to 4 carbon atoms; triaryl phosphorothioates which can be
represented by general formula (4)S.dbd.P(O--Ph--R.sup.5).sub.3
(4)wherein Ph represents a phenyl group, and R.sup.5 is a hydrogen
atom or a linear chain or branched alkyl group which has from 1 to
9 carbon atoms; and acidic phosphate esters which can be
represented by general formula
(5),O.dbd.P(OR.sup.6).sub.3-r(OH).sub.r (5)wherein R.sup.6 is a
linear chain or branched alkyl group which has from 3 to 13 carbon
atoms, and r is an integer of value 1 or 2.
4. The lubricating oil composition of claim 1, wherein the base oil
is a petroleum based and/or synthetic hydrocarbon based oil.
5. The lubricating oil composition of claim 3, wherein said
composition comprises from 0.001 to 0.05 part by weight of the
carboxylic acid-based or carboxylic acid ester-based anti-rust
agent, per 100 parts by weight of lubricating oil base oil.
6. A process for producing a lubricating oil composition comprising
compounding a minor amount of (i) a carboxylic acid-based or
carboxylic acid ester-based anti-rust agent; and (ii) at least one
type of amine selected from the group consisting of (A) alkyl
amines which can be represented by general formula
(1),(R.sup.1).sub.nNH.sub.3-n (1)wherein R.sup.1 represents a
saturated or unsaturated alkyl group which has from 12 to 30 carbon
atoms, and n is an integer of value 1 or 2; and (B)
N-alkylpolyalkylenediamines which can be represented by general
formula (2),R.sup.2NH(CH.sub.2).sub.mNH.sub.2 (2)wherein R.sup.2
represents a saturated or unsaturated alkyl group which has from 12
to 30 carbon atoms, and m is an integer of value from 2 to 5, as an
anti-rust additive combination in a major amount of a lubricating
oil base oil.
7. The process of claim 6 wherein the carboxylic acid-based or
carboxylic acid ester-based anti-rust agent is present in an amount
of from 0.001 to 0.5 part by weight; and the at least one type of
amine is present in an amount of from 0.001 to 0.2 part by weight,
per 100 parts by weight of lubricating oil base oil.
8. The process of claim 6 wherein the at least one type of amine is
present in an amount of from 0.001 to 0.05 part by weight, per 100
parts by weight of lubricating oil base oil composition.
9. The process of claim 6 wherein the process further comprises,
adding as an extreme pressure additive at least one compound
selected from the group consisting of
.beta.-dithiophosphorylpropionic acids which can be represented by
general formula (3),S.dbd.P(--O--R.sup.3).sub.2SCH.sub.2CH-
(R.sup.4)COOH (3)wherein R.sup.3 represents a branched alkyl group
which has from 3 to 8 carbon atoms, and R.sup.4 is a hydrogen atom
or a group selected from among the linear chain or branched alkyl
groups which have from 1 to 4 carbon atoms; triaryl
phosphorothioates which can be represented by general formula
(4)S.dbd.P(O--Ph--R.sup.5).sub.3 (4)wherein Ph represents a phenyl
group, and R.sup.5 is a hydrogen atom or a linear chain or branched
alkyl group which has from 1 to 9 carbon atoms; and acidic
phosphate esters which can be represented by general formula
(5),O.dbd.P(OR.sup.6).sub.3-r(OH).sub.r (5)wherein R.sup.6 is a
linear chain or branched alkyl group which has from 3 to 13 carbon
atoms, and r is an integer of value 1 or 2.
10. A hydraulic oil composition comprising a lubricating oil
composition of claim 1.
11. A compressor oil composition comprising a lubricating oil
composition of claim 1.
12. A turbine oil composition comprising a lubricating oil
composition of claim 1.
13. A bearing oil composition comprising a lubricating oil
composition of claim 1.
14. A gear oil composition comprising a lubricating oil composition
of claim 1.
15. A compressor oil composition comprising a lubricating oil
composition of claim 3.
16. A turbine oil composition comprising a lubricating oil
composition of claim 3.
17. A bearing oil composition comprising a lubricating oil
composition of claim 3.
18. A gear oil composition comprising a lubricating oil composition
of claim 3.
19. A hydraulic oil composition comprising a lubricating oil
composition of claim 3.
20. A lubricating oil composition of claim 3 wherein the extreme
pressure additive is a .beta.-dithiophosphorylpropionic acid which
can be represented by general formula
(3),S.dbd.P(--O--R.sup.3).sub.2SCH.sub.2CH- (R.sup.4)COOH
(3)wherein R.sup.3 represents a branched alkyl group which has from
3 to 8 carbon atoms, and R.sup.4 is a hydrogen atom or a group
selected from among the linear chain or branched alkyl groups which
have from 1 to 4 carbon atoms.
21. A lubricating oil composition of claim 3 wherein the extreme
pressure additive is a triaryl phosphorothioate which can be
represented by general formula (4)S.dbd.P(O--Ph--R.sup.5).sub.3
(4)wherein Ph represents a phenyl group, and R.sup.5 is a hydrogen
atom or a linear chain or branched alkyl group which has from 1 to
9 carbon atoms.
22. A lubricating oil composition of claim 3 wherein the extreme
pressure additive is an acidic phosphate ester which can be
represented by general formula
(5),O.dbd.P(OR.sup.6).sub.3-r(OH).sub.r (5)wherein R.sup.6 is a
linear chain or branched alkyl group which has from 3 to 13 carbon
atoms, and r is an integer of value 1 or 2.
23. A lubricating oil composition of claim 1 wherein the
lubricating oil base oil has a kinematic viscosity of from 2 to 680
mm.sup.2/s (40.degree. C.), a total sulfur content of from 0 to 1
wt. %, a total nitrogen content of from 0 to 100 ppm, and an
aniline point of from 80 to 130.degree. C.
Description
[0001] The present invention relates to a lubricating oil
composition which has excellent anti-rust properties in severe
operating environments in which water or seawater is admixed, and
which also exhibits excellent properties in terms of both the
lubricating properties and anti-corrosion properties in various
types of machinery.
[0002] Anti-rust agents are added to lubricating oils to protect
the mechanical parts from rusting when water or seawater is
admixed. In general, anti-rust agents are strongly adsorbed on the
metal surface to form a rust-proof film on the metal surface thus
preventing direct contact between the metal and water from
occurring and thereby inhibiting the formation of rust.
[0003] On the other hand, the wear surfaces of equipment are being
subjected to ever more severe conditions as a result of increased
running speeds, increased loads and increases in efficiency which
have arisen in recent times, and scorching of the wear surfaces is
likely to occur as a result of the breakdown of the lubricating oil
film.
[0004] Consequently, extreme pressure additives, which react with
the metal surface and maintain the lubricating properties at the
wear surface, are added in suitable amounts to the lubricating oils
which are used under such severe conditions in order to prevent
sticking of the wear surfaces.
[0005] EP-A-0744456 describes a lubricant which comprises at least
one oil of lubricating viscosity and at least (a) at least one
oil-soluble metal-free sulphur-containing anti-wear and/or extreme
pressure agent having a copper corrosion test activity of not more
than 65; (b) at least one oil soluble metal-free phosphorus- and
nitrogen-containing antiwear and/or extreme pressure agent; (c) at
least one oil-soluble organic carboxylic acid; and (d) at least one
oil-soluble organic amine.
[0006] U.S. Pat. No. 5,152,908 discloses a gear lubricant
comprising a major amount of an oil of lubricating viscosity and a
minor amount of an additive package which is comprised of (a) a
treated zinc dithiophosphate, (b) an overbased carboxylate which is
preferably borated, (c) an alkylamine and (d) a sulphurised
olefin.
[0007] WO-A-00/11122 discloses a lubricating oil composition
comprising (I) 100 parts by weight of a base oil for a lubricating
oil; (II) as an anti-wear agent, (i) (a) from 0.05 to 10 parts by
weight of a phosphorothionate as described therein, and (b) from
0.01 to 1.0 part by weight of an amine salt of a phosphorus
compound which phosphorus compound is as described therein, and/or
(ii) from 0.05 to 10 parts by weight of a dithiophosphate as
described therein; (III) as a rust preventing agent, from 0.01 to
1.0 part by weight of a polyalkylene polyamide obtained by reacting
(a) a polyalkylene polyamine as described therein, and (b) a
carboxylic acid having from 4 to 30 carbon atoms.
[0008] EP-A-0434464 describes a lubricant composition which
comprises (a) a metal-free anti-wear or load carrying additive
containing sulphur and/or phosphorus, and (b) a corrosion inhibitor
in the form of an amino succinate ester of formula
R.sub.1OOC(CR.sub.3R.sub.4)CR.sub.5(NR.sub.6R.- sub.7)COOR.sub.2 in
which R.sub.1 and R.sub.2 are each alkyl of 1 to 30 carbon atoms,
R.sub.3, R.sub.4 and R.sub.5 are each hydrogen or alkyl of 1 to 4
carbon atoms, and R.sub.6 and R.sub.7 are each hydrogen, alkyl of 1
to 30 carbon atoms, or an acyl group derived from a saturated or
unsaturated carboxylic acid of up to 30 carbon atoms, at least one
of R.sub.6 and R.sub.7 being an acyl group.
[0009] However, it is known that the compounding of an anti-rust
agent impedes the reaction between the metal surface and an extreme
pressure additive at the wear surface and that the effect of the
extreme pressure additive is to a large extent lost as a
result.
[0010] It is therefore desirable to provide ashless lubricating oil
compositions which contain no metal and which, from the viewpoints
of the lubrication performance and the anti-rust performance of the
lubricating oil, maintain excellent extreme pressure performance
even under severe lubrication conditions and at the same time have
excellent anti-rust properties.
[0011] It has now been surprisingly discovered that the amount of
anti-rust agent added can be greatly reduced by combining specific
alkylamines with the anti-rust agents, with the result that the
reduction in the extreme pressure performance caused by the
anti-rust agent can be suppressed to a minimum level.
[0012] The present invention provides a lubricating oil composition
comprising a minor amount of an additive combination comprising
[0013] (i) a carboxylic acid-based or carboxylic acid ester-based
anti-rust agent;
[0014] (ii) at least one type of amine selected from among the
group comprising (A) the alkyl amines which can be represented by
general formula (1),
(R.sup.1).sub.nNH.sub.3-n (1)
[0015] wherein R.sup.1 represents a saturated or unsaturated alkyl
group which has from 12 to 30 carbon atoms, and n is an integer of
value 1 or 2, and (B) the N-alkylpolyalkylenediamines which can be
represented by general formula (2),
R.sup.2NH(CH.sub.2).sub.mNH.sub.2 (2)
[0016] wherein R.sup.2 represents a saturated or unsaturated alkyl
group which has from 12 to 30 carbon atoms, and m is an integer of
value from 2 to 5; and a major amount of a lubricating oil base
oil.
[0017] By "major amount" in the present invention is meant at least
50 wt. %, with respect to the total weight of the lubricating oil
composition.
[0018] Said composition generally comprises from 0.001 to 0.5 part
by weight of the carboxylic acid-based or carboxylic acid
ester-based anti-rust agent; and from 0.001 to 0.2 part by weight
of the at least one type of amine, per 100 parts by weight of
lubricating oil base oil.
[0019] Preferably, said composition comprises from 0.001 to 0.05
part by weight of the carboxylic acid-based or carboxylic acid
ester-based anti-rust agent, per 100 parts by weight of lubricating
oil base oil. More preferably, said composition comprises from
0.005 to 0.05 part by weight of said anti-rust agent, per 100 parts
by weight of lubricating oil base oil.
[0020] Preferably, said composition comprises from 0.001 to 0.05
part by weight of the at least one type of amine, per 100 parts by
weight of lubricating oil base oil.
[0021] In a further embodiment of the present invention, the
lubricating oil composition comprises, as an extreme pressure
additive, a .beta.-dithiophosphorylpropionic acid which can be
represented by general formula (3),
S.dbd.P(O--R.sup.3).sub.2SCH.sub.2CH(R.sup.4)COOH (3)
[0022] wherein R.sup.3 represents a branched alkyl group which has
from 3 to 8 carbon atoms, and R.sup.4 is a hydrogen atom or a group
selected from among the linear chain or branched alkyl groups which
have from 1 to 4 carbon atoms.
[0023] Said extreme pressure additive of formula (3) is preferably
present in an amount in the range of from 0.001 to 0.5 part by
weight, more preferably from 0.001 to 0.02 part by weight, per 100
parts by weight of lubricating oil base oil.
[0024] In a still further embodiment of the present invention, the
lubricating oil composition comprises, as an extreme pressure
additive, a triaryl phosphorothioate which can be represented by
general formula (4),
S.dbd.P(O--Ph--R.sup.5).sub.3 (4)
[0025] wherein Ph represents a phenyl group, and R.sup.5 is a
hydrogen atom or a linear chain or branched alkyl group which has
from 1 to 9 carbon atoms.
[0026] Said extreme pressure additive of formula (4) is preferably
present in an amount in the range of from 0.05 to 5 parts by
weight, more preferably from 0.05 to 0.5 part by weight, per 100
parts by weight of lubricating oil base oil.
[0027] In another embodiment of the present invention, the
lubricating oil composition comprises, as an extreme pressure
additive, an acidic phosphate ester which can be represented by
general formula (5),
O.dbd.P(OR.sup.6).sub.3-r(OH).sub.r (5)
[0028] wherein R.sup.6 is a linear chain or branched alkyl group
which has from 3 to 13 carbon atoms, and r is an integer of value 1
or 2.
[0029] Said extreme pressure additive of formula (5) is preferably
present in an amount in the range of from 0.01 to 0.5 part by
weight, more preferably from 0.01 to 0.1 part by weight, per 100
parts by weight of lubricating oil base oil.
[0030] The lubricating oil composition of the present invention may
optionally comprise one or more of compounds of formulae (3) to (5)
as extreme pressure additives.
[0031] The lubricating oil base oil from which the lubricating oil
composition of the present invention is constituted is not subject
to any particular limitation, provided that it comprises
petroleum-based oil and/or synthetic hydrocarbon-based oil.
[0032] Lubricating oil base oils having a kinematic viscosity of
from 2 to 680 mm.sup.2/s (40.degree. C.), preferably of from 5 to
320 mm.sup.2/s (40.degree. C.), and most preferably of from 8 to
220 mm.sup.2/s (40.degree. C.); a total sulphur content (wt. %) of
from 0 to 1 wt. %, and preferably of from 0 to 0.3 wt. %; a total
nitrogen content (wt. ppm) of from 0 to 100 ppm, and preferably of
from 0 to 30 ppm; and an aniline point of from 80 to 130.degree.
C., and preferably of from 100 to 125.degree. C., are
preferred.
[0033] The petroleum-based lubricating oil base oils which can be
used in the present invention may be, for example, individual
solvent refined base oils, hydrogenation refined base oils or
highly hydrogenated and cracked base oils, or mixtures of such
oils. Highly hydrogenated cracked base oils are lubricating oil
base oils which have a viscosity index of at least 130 (typically
from 145 to 155) obtained with a slack wax which has been cracked
and solvent de-waxed as the raw material by isomerizing the linear
chain paraffins to branched paraffins by hydrogenation cracking in
the presence of a catalyst (contact cracking), or lubricating base
oils which have a viscosity index of at least 130 (typically from
145 to 155) obtained using heavy linear chain paraffins which have
been obtained by Fischer-Tropsch polymerization using the carbon
monoxide and hydrogen obtained by a gasification process (partial
oxidation) of a natural gas (such as methane) and subjecting this
to catalytic cracking and isomerization in the same way as
above.
[0034] Furthermore, the synthetic hydrocarbon-based base oils which
may be used in the present invention include the olefin oligomers
obtained by the homopolymerization or copolymerization of monomers
which have been selected from among the linear chain and branched
olefinic hydrocarbons which have from 3 to 15 carbon atoms, and
preferably from 4 to 12 carbon atoms.
[0035] In the present invention, the petroleum based lubricating
oil base oils and synthetic hydrocarbon based base oils can be used
individually or in the form of mixtures.
[0036] The carboxylic acid based or carboxylic acid ester-based
anti-rust agents which can be used in the present invention have a
carboxylic acid or carboxylic acid ester group in the anti-rust
agent molecule and they are widely used generally in lubricating
oils.
[0037] Said anti-rust agents include, for example, monocarboxylic
acids which have from 8 to 30 carbon atoms, alkyl or alkenyl
succinates or partial esters thereof, hydroxy-fatty acids which
have from 12 to 30 carbon atoms and derivatives thereof, sarcosines
which have from 8 to 24 carbon atoms and derivatives thereof, amino
acids and derivatives thereof, naphthenic acid and derivatives
thereof, lanolin fatty acid, mercapto-fatty acids and paraffin
oxides.
[0038] Particularly preferred anti-rust agents are indicated
below.
[0039] Examples of Monocarboxylic Acids (C8-C30)
[0040] Caprylic acid, pelargonic acid, decanoic acid, undecanoic
acid, lauric acid, myristic acid, palmitic acid, stearic acid,
arachic acid, behenic acid, cerotic acid, montanic acid, melissic
acid, oleic acid, docosanic acid, erucic acid, eicosenic acid, beef
tallow fatty acid, soy bean fatty acid, coconut oil fatty acid,
linolic acid, linoleic acid, tall oil fatty acid, 12-hydroxystearic
acid, laurylsarcosinic acid, myritsylsarcosinic acid,
palmitylsarcosinic acid, stearylsarcosinic acid, oleylsarcosinic
acid, alkylated (C8-C20) phenoxyacetic acids, lanolin fatty acid
and C8-C24 mercapto-fatty acids.
[0041] Examples of Polybasic Carboxylic Acids
[0042] The alkenyl (C20-C100) succinic acids indicated in CAS No.
27859-58-1 and ester derivatives thereof, dimer acid,
N-acyl-N-alkyloxyalkyl aspartic acid esters (U.S. Pat. No.
5,275,749) which have the structural formula indicated below and
the compounds of CAS No. 68906-34-3. 1
[0043] wherein R.sup.7 and R.sup.8 each independently represent
hydrogen or a group selected from among the C1 to C30 alkyl groups,
the C1 to C30 acyl groups and the alkyloxide groups, and R.sup.9 to
R.sup.13 each independently represent hydrogen or a group selected
from among the C1 to C30 alkyl groups.)
[0044] Examples of the aforementioned alkylamines represented by
general formula (1) include primary amines such as laurylamine,
coconut-amine, n-tridecylamine, myristylamine, n-pentadecylamine,
palmitylamine, n-heptadecylamine, stearylamine, n-nonadecylamine,
n-eicosylamine, n-heneicosylamine, n-docosylamine, n-tricosylamine,
n-pentacosylamine, oleylamine, beef tallow-amine, hydrogenated beef
tallow-amine and soy bean-amine. Examples of the secondary amines
include dilaurylamine, di-coconut-amine, di-n-tridecylamine,
dimyristylamine, di-n-pentadecylamine, dipalmitylamine,
di-n-pentadecylamine, distearylamine, di-n-nonadecylamine,
di-n-eicosylamine, di-n-heneicosylamine, di-n-docosylamine,
di-n-tricosylamine, di-n-pentacosyl-amine, dioleylamine, di-beef
tallow-amine, di-hydrogenated beef tallow-amine and di-soy
bean-amine.
[0045] Examples of the aforementioned N-alkylpolyalkyenediamines
which can be represented by general formula (2) include
ethylenediamines such as laurylethylenediamine, coconut
ethylenediamine, n-tridecylethylenediamine- ,
myristylethylenediamine, n-pentadecylethylenediamine,
palmitylethylenediamine, n-heptadecylethylenediamine,
stearylethylenediamine, n-nonadecylethylenediamine,
n-eicosylethylenediamine, n-heneicosylethylenediamine,
n-docosylethylendiamine, n-tricosylethylenediamine,
n-pentacosylethylenediamine, oleylethylenediamine, beef
tallow-ethylenediamine, hydrogenated beef tallow-ethylenediamine
and soy bean-ethylenediamine; propylenediamines such as
laurylpropylenediamine, coconut propylenediamine,
n-tridecylpropylenediamine, myristylpropylenediamine,
n-pentadecylpropylenediamine, palmitylpropylenediamine,
n-heptadecylpropylenediamine, stearylpropylenediamine,
n-nonadecylpropylenediamine, n-eicosylpropylenediamine,
n-heneicosylpropylenediamine, n-docosylpropylendiamine,
n-tricosylpropylenediamine, n-pentacosylpropylenediamine,
oleylpropylenediamine, beef tallow-propylenediamine, hydrogenated
beef tallow-propylenediamine and soy bean-propylenediamine;
butylenediamines such as laurylbutylenediamine, coconut
butylenediamine, n-tridecylbutylenediamine- ,
myristylbutylenediamine, n-pentadecylbutylenediamine,
stearylbutylenediamine, n-eicosylbutylenediamine,
n-heneicosylbutylenedia- mine, n-docosylbutylendiamine,
n-tricosylbutylenediamine, n-pentacosylbutylenediamine,
oleylbutylenediamine, beef tallow-butylenediamine, hydrogenated
beef tallow-butylenediamine and soy bean butylenediamine; and
pentylenediamines such as laurylpentylenediamine, coconut
pentylenediamine, myristylpentylenediamin- e,
palmitylpentylenediamine, stearylpentylenediamine,
oleyl-pentylenediamine, beef tallow-pentylenediamine, hydrogenated
beef tallow-pentylenediamine and soy bean pentylenediamine.
[0046] In addition to the aforementioned components, suitable
amounts of supplementary additives of the various types which are
generally used can be added to the lubricating oil composition of
the present invention, as required, in order to further improve the
performance thereof. Supplementary additives that may be added to
the lubricating oil composition of the present invention include
the known lubricating oil additives such as antioxidants, metal
deactivators, extreme pressure additives, antifoaming agents,
viscosity index increasing agents, flow-point reducing agents,
cleaning and dispersing agents, anti-rust agents and
anti-emulsification agents.
[0047] Examples of amine-based antioxidants include
dialkyldiphenylamines such as p,p'-dioctyldiphenylamine
(manufactured by the Seiko Kagaku Co. under the trade designation
"Nonflex OD-3"), p,p'-di-.alpha.-methylbenzyl- diphenylamine and
N-p-butylphenyl-N-p'-octylphenylamine; monoalkyldiphenylamines such
as mono-t-butyldiphenylamine, and monooctyldiphenylamine;
bis(dialkylphenyl)amines such as di(2,4-diethylphenyl)amine and
di(2-ethyl-4-nonylphenyl)amine; alkylphenyl-1-naphthylamines such
as octylphenyl-1-naphthylamine and
N-t-dodecylphenyl-1-naphthylamine; arylnaphthylamines such as
1-naphthylamine, phenyl-1-naphthylamine, phenyl-2-naphthylamine,
N-hexylphenyl-2-naphthylamine and N-octylphenyl-2-naphthylamine,
phenylenediamines such as N,N'-diisopropyl-p-phenylenediamine and
N,N'-diphenyl-p-phenylenediamine, and phenothiazines such as
phenothiazine (manufactured by the Hodogaya Kagaku Co.:
Phenothiazine) and 3,7-dioctylphenothiazine.
[0048] Examples of sulphur-based antioxidants include
dialkylsulphides such as didodecylsulphide and dioctadecylsulphide;
thiodipropionic acid esters such as didodecyl thiodipropionate,
dioctadecyl thiodipropionate, dimyristyl thiodipropionate and
dodecyloctadecyl thiodipropionate, and 2-mercaptobenzimidazole.
[0049] Examples of phenol-based antioxidants include
2-t-butylphenol, 2-t-butyl-4-methylphenol,
2-t-butyl-5-methylphenol, 2,4-di-t-butylphenol,
2,4-dimethyl-6-t-butylphenol, 2-t-butyl-4-methoxyphenol,
3-t-butyl-4-methoxyphenol, 2,5-di-t-butylhydroquinone (manufactured
by the Kawaguchi Kagaku Co. under trade designation "Antage DBH"),
2,6-di-t-butylphenol and 2,6-di-t-butyl-4-alkylphenols such as
2,6-di-t-butyl-4-methylphenol and 2,6-di-t-butyl-4-ethylphenol;
2,6-di-t-butyl-4-alkoxyphenols such as
2,6-di-t-butyl-4-methoxyphenol and 2,6-di-t-butyl-4-ethoxyphenol,
3,5-di-t-butyl-4-hydroxybenzylmercaptoocty- l acetate,
alkyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionates such as
n-octyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate (manufactured
by the Yoshitomi Seiyaku Co. under the trade designation "Yonox
SS"), n-dodecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and
2'-ethylhexyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate;
2,6-di-t-butyl-.alpha.-dimethylamino-p-cresol,
2,2'-methylenebis(4-alkyl-- 6-t-butylphenol) compounds such as
2,2'-methylenebis(4-methyl-6-t-butylphe- nol) (manufactured by the
Kawaguchi Kagaku Co. under the trade designation "Antage W-400")
and 2,2'-methylenebis(4-ethyl-6-t-butylphenol) (manufactured by the
Kawaguchi Kagaku Co. under the trade designation "Antage W-500");
bisphenols such as 4,4'-butylidenebis(3-methyl-6-t-butyl- phenol)
(manufactured by the Kawaguchi Kagaku Co. under the trade
designation "Antage W-300"),
4,4'-methylenebis(2,6-di-t-butylphenol) (manufactured by Laporte
Performance Chemicals under the trade designation "Ionox 220AH"),
4,4'-bis(2,6-di-t-butylphenol), 2,2-(di-p-hydroxyphenyl)propane
(Bisphenol A), 2,2-bis(3,5-di-t-butyl-4-h- ydroxyphenyl)propane,
4,4'-cyclohexylidenebis(2,6-di-t-butylphenol), hexamethylene glycol
bis[3, (3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by
the Ciba Speciality Chemicals Co. under the trade designation
"Irganox L109"), triethylene glycol bis[3-(3-t-butyl-4-hydrox-
y-5-methylphenyl)propionate] (manufactured by the Yoshitomi Seiyaku
Co. under the trade designation "Tominox 917"),
2,2'-thio[diethyl-3-(3,5-di-t- -butyl-4-hydroxyphenyl)propionate]
(manufactured by the Ciba Speciality Chemicals Co. under the trade
designation "Irganox L115"),
3,9-bis{1,1-dimethyl-2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)-propionylo-
xy]ethyl}2,4, 8, 10-tetraoxaspiro[5,5]undecane (manufactured by the
Sumitomo Kagaku Co. under the trade designation "Sumilizer GA80")
and 4,4'-thiobis(3-methyl-6-t-butylphenol) (manufactured by the
Kawaguchi Kagaku Co. under the trade designation "Antage RC"),
2,2'-thiobis(4,6-di-t-butylresorcinol); polyphenols such as
tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionato]methane
(manufactured by the Ciba Speciality Chemicals Co. under the trade
designation "Irganox L101"),
1,1,3-tris(2-methyl-4-hydroxy-5-t-butylpheny- l)butane
(manufactured by the Yoshitomi Seiyaku Co. under the trade
designation "Yoshinox 930"),
1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-- hydroxybenzyl)benzene
(manufactured by Ciba Speciality Chemicals under the trade
designation "Irganox 330"),
bis[3,3'-bis(4'-hydroxy-3'-t-butylpheny- l)butyric acid] glycol
ester, 2-(3',5'-di-t-butyl-4-hydroxyphenyl)-methyl--
4-(2",4"-di-t-butyl-3"-hydroxyphenyl)methyl-6-t-butylphenol and
2,6-bis(2'-hydroxy-3'-t-butyl-5'-methylbenzyl)-4-methylphenol; and
phenol/aldehyde condensates such as the condensates of
p-t-butylphenol and formaldehyde and the condensates of
p-t-butylphenol and acetaldehyde.
[0050] Examples of phosphorus-based antioxidants include triaryl
phosphites such as triphenyl phosphite and tricresyl phosphite,
trialkyl phosphites such as trioctadecyl phosphite and tridecyl
phosphite, and tridodecyl trithiophosphite.
[0051] These antioxidants can be used individually or in the form
of mixtures, conveniently in amounts within the range of from 0.01
to 2.0 parts by weight, per 100 parts by weight of base oil.
[0052] The metal deactivating agents which can be used in the
lubricating oil a composition of the present invention include
benzotriazole and the 4-alkylbenzotriazoles such as
4-methylbenzotriazole and 4-ethylbenzotriazole;
5-alkylbenzotriazoles such as 5-methylbenzotriazole,
5-ethylbenzotriazole; 1-alkylbenzotriazoles such as
1-dioctylauainomethyl-2,3-benzotriazole; benzotriazole derivatives
such as the 1-alkyltolutriazoles, for example,
1-dioctylaminomethyl-2,3-t- olutriazole; benzimidazole and
benzimidazole derivatives such as 2-(alkyldithio)-benzimidazoles,
for example, such as 2-(octyldithio)-benzimidazole,
2-(decyldithio)benzimidazole and 2-(dodecyldithio)-benzimidazole;
2-(alkyldithio)-toluimidazoles such as
2-(octyldithio)-toluimidazole, 2-(decyldithio)-toluimidazole and
2-(dodecyldithio)-toluimidazole; indazole and indazole derivatives
of toluimidazoles such as 4-alkylindazole, 5-alkylindazole;
benzothiazole, 2-mercaptobenzothiazole derivatives (manufactured by
the Chiyoda Kagaku Co. under the trade designation "Thiolite
B-3100") and 2-(alkyldithio)benzothiazoles such as
2-(hexyldithio)benzothiazole and 2-(octyldithio)benzothiazole;
2-(alkyl-dithio)toluthiazoles such as 2-(benzyldithio)toluthiazole
and 2-(octyldithio)toluthiazole,
2-(N,N-dialkyldithiocarbamyl)benzothiazoles such as
2-(N,N-diethyldithiocarbamyl)benzothiazole,
2-(N,N-dibutyldithiocarbamyl)- benzotriazole and
2-N,N-dihexyl-dithiocarbamyl)benzotriazole; benzothiazole
derivatives of 2-(N,N-dialkyldithiocarbamyl)toluthiazoles such as
2-(N,N-diethyldithiocarbamyl)toluthiazole,
2-(N,N-dibutyldithiocarbamyl)toluthiazole,
2-(N,N-dihexyl-dithiocarbamyl)- toluthiazole;
2-(alkyldithio)benzoxazoles such as 2-(octyldithio)benzoxazo- le,
2-(decyldithio)-benzoxazole and 2-(dodecyldithio)benzoxazole;
benzoxazole derivatives of 2-(alkyldithio)toluoxazoles such as
2-(octyldithio)toluoxazole, 2-(decyldithio)toluoxazole,
2-(dodecyldithio)toluoxazole;
2,5-bis(alkyldithio)-1,3,4-thiadiazoles such as
2,5-bis(heptyldithio)-1,3,4-thiadiazole, 2,5-bis-(nonyldithio)-1,-
3,4-thiadiazole, 2,5-bis(dodecyldithio)-1,3,4-thiadiazole and
2,5-bis-(octadecyldithio)-1,3,4-thiadiazole;
2,5-bis(N,N-dialkyl-dithioca- rbamyl)-1,3,4-thiadiazoles such as
2,5-bis(N,N-diethyldithiocarbamyl)-1,3,- 4-thiadiazole,
2,5-bis(N,N-dibutyldithiocarbamyl)-1,3,4-thiadiazole and
2,5-bis(N,N-dioctyldithiocarbamyl)1,3,4-thiadiazole; thiadiazole
derivatives of
2-N,N-dialkyldithiocarbamyl-5-mercapto-1,3,4-thiadiazoles such as
2-N,N-dibutyldithiocarbamyl-5-mercapto-1,3,4-thiadiazole and
2-N,N-dioctyl-dithiocarbamyl-5-mercapto-1,3,4-thiadiazole, and
triazole derivatives of 1-alkyl-2,4-triazoles such as
1-dioctylaminomethyl-2,4-tri- azole.
[0053] These metal deactivating agents can be used individually or
in the form of mixtures, conveniently in an amount within the range
of from 0.01 to 0.5 parts by weight, per 100 parts by weight of
base oil.
[0054] The materials which can be used as anti-foaming agents
include, for example, dimethylpolysiloxane, organosilicates such as
diethylsilicate, the fluorosilicones, and non-silicone based
anti-foaming agents such as poly(alkylene acrylate). These can be
added and used individually or in the form of mixtures,
conveniently in an amount of from 0.0001 to 0.1 part by weight, per
100 parts by weight of base oil.
[0055] The viscosity index increasing agents which can be used
include, for example, polymethacrylates and ethylene/propylene
copolymers, other non-dispersion type viscosity index increasing
agents such as olefin copolymers like styrene/diene copolymers, and
dispersible type viscosity index increasing agents where a nitrogen
containing monomer has been copolymerized in such materials. These
materials can be added and used individually or in the form of
mixtures, conveniently in an amount within the range of from 0.05
to 20 parts by weight per 100 parts by weight of base oil.
[0056] Examples of flow-point reducing agents include
polymethacrylate based polymers. These materials can be added and
conveniently used in an amount within the range from 0.01 to 5
parts by weight per 100 parts by weight of base oil.
[0057] Examples of the cleaning and dispersing agents which can be
used include metal-based detergents such as the neutral and basic
alkaline earth metal sulphonates, alkaline earth metal phenates and
alkaline earth metal salicylates alkenylsuccinimide and
alkenylsuccinimide esters and their borohydrides, and ashless
dispersing agents which have been modified with sulphur compounds.
These agents can be added and used individually or in the form of
mixtures, conveniently in an amount within the range of from 0.01
to 1 part by weight per 100 parts by weight of base oil.
[0058] Examples of extreme pressure additives include sulphur-based
extreme pressure additives such as dialkyl sulphides, dibenzyl
sulphide, dialkyl polysulphides, dibenzyl disulphide, alkyl
mercaptans, dibenzothiophene and 2,2'-dithiobis(benzothiazole);
phosphorus-based extreme pressure additives such as trialkyl
phosphates, triaryl phosphates, trialkyl phosphonates, trialkyl
phosphites, triaryl phosphites and dialkylhydrozine phosphites, and
phosphorus- and sulphur-based extreme pressure additives such as
zinc dialkyldithiophosphates, dialkylthiophosphoric acid, trialkyl
thiophosphate esters, acidic thiophosphate esters and trialkyl
trithiophosphates. These extreme pressure additives can be used
individually or in the form of mixtures, conveniently in an amount
within the range from 0.1 to 2 parts by weight, per 100 parts by
weight of the base oil.
[0059] The known anti-emulsifying agents which are generally used
as lubricating oil additives can also be used. These agents may be
conveniently added and used in an amount within the range from
0.0005 to 0.5 part by weight, per 100 parts by weight of the base
oil.
[0060] Examples of anti-emulsifying agents include polyalkylene
glycol-based non-ionic surfactants, for example,
polyoxyethylenealkyl ethers, polyoxyethylene alkylphenyl ethers and
polyoxyethylene alkylnaphthyl ethers.
[0061] The lubricating oil composition of the present ivnention is
useful as a hydraulic oil composition, a compressor oil
composition, a turbine oil composition, a bearing oil composition
and/or a gear oil composition.
[0062] The present invention will now be described with reference
to the following Examples which are not intended to limit the scope
of the present invention in any way.
ILLUSTRATIVE EXAMPLES
[0063] Sample oils were prepared by compounding extreme pressure
additives and carboxylic acid based and carboxylic acid ester-based
anti-rust agents and amines at various concentrations as shown in
Table 1 in a hydrogenation refined base oil of kinematic viscosity
31 mm.sup.2/s at 40.degree. C. with a viscosity index of 107, a
sulphur content of less than 5 ppm, a nitrogen content of less than
1 ppm and an aniline point of 112.degree. C. as the base oil.
[0064] The effect of the invention was investigated in terms of the
anti-rust agent performance and the extreme pressure
performance.
[0065] The test methods used for assessing performance in the
Examples and Comparative Examples were as indicated below.
[0066] Anti-rust Test
[0067] In order to evaluate the anti-rust performance of the sample
oils, an anti-rust test was carried out for 24 hours at 60.degree.
C. in the presence of artificial seawater in accordance with ASTM
D665. It was investigated whether or not rust had formed on the
steel specimen after the test.
[0068] FZG Gear Wheel Test
[0069] In order to evaluate the lubrication performance of the
sample oils in gear wheel equipment, the A test gear wheels were
used in accordance with ISO/WD14635-1 and the gears were run for 15
minutes at each loading stage at an initial oil temperature of
90.degree. C. and a motor speed of 1450 rpm. The loading stage at
which scorching occurred on the tooth surfaces of the test gear
wheel as the load was being increased in stages was observed.
Examples 1 to 9 and Comparative Examples 1 to 9
[0070] The compositions and test results are shown in Tables 1 to
3.
1TABLE 1 Comp. Comp. Comp. Comp. Comp. Comp. Comp.
Example/Comparative Example Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex.
7 Base Oil, wt % 99.98 99.93 99.93 99.94 99.94 99.94 99.78 Extreme
Pressure Additive, wt % 0.02 0.02 0.02 0.02 0.02 0.02 0.02
3(O,O-diisobutyl-dithiophosphoryl)-2-methyl- propionic acid
Triphenyl phosphothioate -- -- -- -- -- -- -- Isobutyl acidic
phosphate ester -- -- -- -- -- -- -- Carboxylic Acid-, Carboxylic
Acid Ester-Based Anti-rust Agent Component, wt % Polyalkylene
succinic acid half ester (1) -- -- 0.05 -- -- -- -- N-Oleyl
sarcosinic acid (2) -- -- -- 0.04 -- -- -- Nonyl phenoxyacetate (3)
-- -- -- -- 0.04 -- -- N-Acyl-N-alkoxyalkyl aspartic acid ester A
(4) -- -- -- -- -- 0.04 -- N-Acyl-N-alkoxyalkyl aspartic acid ester
B (5) -- -- -- -- -- -- 0.20 Amine Component, wt % Coconut-amine --
0.05 -- -- -- -- -- Oleylamine -- -- -- -- -- -- --
Di-coconut-amine -- -- -- -- -- -- -- Beef Tallow propylenediamine
-- -- -- -- -- -- -- Anti-rust Test Results Rust Rust No No No No
No formed Formed Rust Rust Rust Rust Rust FZG Gear Wheel Test
Results >12 >12 8 8 8 9 9 Minimum Failing Load Stage
[0071]
2TABLE 2 Comp. Comp. Example/Comparative Example Ex. 8 Ex. 9 Ex. 1
Ex. 2 Ex. 3 Ex. 4 Ex. 5 Base Oil, wt % 99.53 99.35 99.95 99.955
99.95 99.955 99.88 Extreme Pressure Additive, wt % -- -- 0.02 0.02
0.02 0.02 0.02 3(O,O-diisobutyl-dithiophosphoryl)-2-methyl-
propionic acid Triphenyl phosphothioate 0.50 0.50 -- -- -- -- --
Isobutyl acidic phosphate ester 0.10 0.10 -- -- -- -- Carboxylic
Acid-, Carboxylic Acid Ester-Based Anti-rust Agent Component, wt %
Polyalkylene succinic acid half ester (1) -- -- 0.01 -- -- -- --
N-Oleyl sarcosinic acid (2) -- -- -- 0.005 -- -- -- Nonyl
phenoxyacetate (3) -- -- -- -- 0.01 -- -- N-Acyl-N-alkoxyalkyl
aspartic acid ester A (4) 0.05 -- -- -- -- 0.005 --
N-Acyl-N-alkoxyalkyl aspartic acid ester B (5) -- -- -- -- -- --
0.05 Amine Component, wt % Coconut-amine -- 0.05 0.02 0.02 0.02
0.02 0.05 Oleylamine -- -- -- -- -- -- -- Di-coconut-amine -- -- --
-- -- -- -- Beef Tallow propylenediamine -- -- -- -- -- -- --
Anti-rust Test Results No Rust No No No No No Rust Formed Rust Rust
Rust Rust Rust FZG Gear Wheel Test Results Minimum Failing 9 >12
11 11 10 >12 11 Load Stage
[0072]
3TABLE 3 Example/Comparative Example Example 6 Example 7 Example 8
Example 9 Base Oil, wt % 99.955 99.945 99.955 99.37 Extreme
Pressure Additive, wt % 3(O,O-diisobutyl- 0.02 0.02 0.02 --
dithiophosphoryl)- 2-methyl- propionic acid Triphenyl
phosphothioate -- -- -- 0.50 Isobutyl acidic phosphate -- -- --
0.10 ester Carboxylic Acid-, Carboxylic Acid Ester-Based Anti-rust
Agent Component, wt % Polyalkylene succinic -- -- -- -- acid half
ester (1) N-Oleyl sarcosinic -- -- -- -- acid (2) Nonyl
phenoxyacetate -- -- -- -- (3) N-Acyl-N-alkoxyalkyl 0.005 0.005
0.005 0.01 aspartic acid ester A (4) N-Acyl-N-alkoxyalkyl -- -- --
-- aspartic acid ester B (5) Amine Component, wt % Coconut-amine --
-- -- 0.02 Oleylamine 0.02 -- -- -- Di-coconut-amine -- 0.03 -- --
Beef Tallow -- -- 0.02 -- propylenediamine Anti-rust Test Results
No Rust No Rust No Rust No Rust FZG Gear Wheel Test >12 >12
>12 >12 Results Minimum Failing Load Stage NOTES: (1)
manufactured by the Lubrizol Co under the trade designation
"Lubrizol 859". (2) manufactured by the Ciba Speciality Chemicals
Co. under the trade designation "Sarcosil O". (3) manufactured by
the Ciba Speciality Chemicals Co. under the trade designation
"Irgacore NPA". (4) manufactured by the Colonial Chemical Co. under
the trade designation "Korakoa 93". (5) CAS No. 68906-34-3,
27136-73-8. (6) manufactured by the King Industries Co. under the
trade designation "K-CORR 100". Anti-rust agent disclosed in
US-A-5,275,749.
[0073] Comparative Example 1 had only the extreme pressure additive
compounded therein. Whilst said example and exhibited good extreme
pressure performance in the gear wheel test, rust formed in the
anti-rust test as no anti-rust agent and amine had been added
thereto.
[0074] In contrast, in Comparative Examples 3 to 8 the minimum
amount of carboxylic acid-based or carboxylic acid ester-based
anti-rust agent had been added thereto and thus no rust formed in
the anti-rust test. However, there was a marked fall in the durable
load in the FZG gear wheel test as a result of the addition of the
anti-rust agent.
[0075] Furthermore, only the amine had been added in Comparative
Examples 2 and 9, with no carboxylic acid-based or carboxylic acid
ester-based anti-rust agent also being added. Adequate anti-rust
effect was not obtained.
[0076] With Examples 1 to 9, which are according to the present
invention, the amount of carboxylic acid-based or carboxylic acid
ester-based anti-rust agent required was greatly reduced as a
result of the synergistic effect between the amine and the
carboxylic acid-based or carboxylic acid ester-based anti-rust
agent which are essential components of the invention, and there
was a great improvement in respect of the fall in the extreme
pressure performance which was caused by the anti-rust agent.
[0077] The lubricating oil compositions of the present invention
are virtually free, or completely free, of metals which are harmful
in respect of both the environment and safety and they maintain a
good anti-rust performance whilst also having good extreme pressure
performance to match the increased speeds, higher pressures, more
compact nature and improvement in durability requirements of modern
industrial machinery.
[0078] Furthermore, the amount of anti-rust agent added can be
reduced by means of the present invention and lubricating oil
compositions which have excellent performance can be provided more
cheaply.
[0079] The lubricating oil compositions of the present invention
are useful as lubricating oil compositions where both anti-rust
performance and extreme pressure performance are required and they
can be used as hydraulic working oils, gear wheel oils, compressor
oils, turbine oils and bearing oils.
* * * * *