U.S. patent application number 16/302128 was filed with the patent office on 2019-09-19 for lubricating oil composition containing an antifoaming agent.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Hiroyuki Kaneko, Hiroshi Seto.
Application Number | 20190284501 16/302128 |
Document ID | / |
Family ID | 59738370 |
Filed Date | 2019-09-19 |
United States Patent
Application |
20190284501 |
Kind Code |
A1 |
Seto; Hiroshi ; et
al. |
September 19, 2019 |
LUBRICATING OIL COMPOSITION CONTAINING AN ANTIFOAMING AGENT
Abstract
Provided is a lubricating oil composition containing an
antifoaming agent having high antifoaming performance even when the
lubricant base oil has low viscosity. The lubricating oil
composition comprises a lubricant base oil and drops of an
antifoaming agent dispersion system dispersed in the lubricant base
oil, wherein the antifoaming agent dispersion system comprises a
dispersion medium mixture and an antifoaming agent dispersed in the
dispersion medium mixture, and the dispersion medium mixture
comprises a dispersion medium and an additive for dispersion.
Inventors: |
Seto; Hiroshi;
(Kawasaki-shi, JP) ; Kaneko; Hiroyuki;
(Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annadale |
NJ |
US |
|
|
Family ID: |
59738370 |
Appl. No.: |
16/302128 |
Filed: |
May 19, 2017 |
PCT Filed: |
May 19, 2017 |
PCT NO: |
PCT/IB2017/000600 |
371 Date: |
November 16, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2030/18 20130101;
C10M 169/04 20130101; C10N 2040/04 20130101; C10N 2020/02 20130101;
C10M 2203/1025 20130101; C10N 2040/042 20200501; C10N 2070/02
20200501; C10M 169/044 20130101; C10M 177/00 20130101; C10M 2215/28
20130101; C10M 2229/051 20130101; C10M 2203/1006 20130101; C10M
2205/0285 20130101 |
International
Class: |
C10M 177/00 20060101
C10M177/00; C10M 169/04 20060101 C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 20, 2016 |
JP |
2016-101673 |
Claims
1. A lubricating oil composition comprising a lubricant base oil
and an antifoaming agent contained in the lubricant base oil,
wherein the lubricating oil composition comprises a lubricant base
oil and drops of an antifoaming agent dispersion system dispersed
in the lubricant base oil; the antifoaming agent dispersion system
comprises a dispersion medium mixture and an antifoaming agent
dispersed in the dispersion medium mixture; and the dispersion
medium mixture comprises a dispersion medium and an additive for
dispersion.
2. The lubricating oil composition according to claim 1, wherein
the antifoaming agent is fluoroalkylpolysiloxane.
3. The lubricating oil composition according to claim 1, wherein
the additive for dispersion is at least one selected from the group
consisting of an ashless dispersant, a metallic detergent, an
antiwear agent, a friction conditioner and an extreme pressure
agent.
4. The lubricating oil composition according to claim 3, wherein
the ashless dispersant is selected from a succinimide compound, a
succinamide compound and combinations thereof.
5. The lubricating oil composition according to claim 1, wherein
the dispersion medium mixture has a kinematic viscosity of 5-50,000
mm.sup.2/s at 40.degree. C.
6. The lubricating oil composition according to claim 1, wherein
the dispersion medium is selected from a mineral oil, a synthetic
oil and combinations thereof.
7. The lubricating oil composition according to claim 1, wherein an
antifoaming agent content in the lubricating oil composition is
0.01-500 ppm in terms of elemental fluorine (F) and 0.05-400 ppm in
terms of elemental silicon (Si).
8. The lubricating oil composition according to claim 1, which is
for a transmission, for a gear, for gear oil, for a gear box, for
an automotive gear box, for an industrial gear box, or for a
transmission fluid.
9. A method for manufacturing a lubricating oil composition
comprising a lubricant base oil and an antifoaming agent contained
in the lubricant base oil, comprising the steps of mixing a
dispersion medium and an additive for dispersion to prepare a
dispersion medium mixture; mixing an antifoaming agent with the
dispersion medium mixture and dispersing the antifoaming agent in
the dispersion medium mixture to prepare an antifoaming agent
dispersion system; and then dispersing the antifoaming agent
dispersion system in a lubricant base oil.
10. The method for manufacturing a lubricating oil composition
according to claim 9, wherein the antifoaming agent is
fluoroalkylpolysiloxane.
11. The method for manufacturing a lubricating oil composition
according to claim 9, wherein the additive for dispersion is at
least one selected from the group consisting of an ashless
dispersant, a metallic detergent, an antiwear agent, a friction
conditioner and an extreme pressure agent.
12. The method for manufacturing a lubricating oil composition
according to claim 11, wherein the ashless dispersant is selected
from a succinimide compound, a succinamide compound and
combinations thereof.
13. The method for manufacturing a lubricating oil composition
according to claim 9, wherein the dispersion medium mixture has a
kinematic viscosity of 5-50,000 mm.sup.2/s at 40.degree. C.
14. The method for manufacturing a lubricating oil composition
according to claim 9, wherein the dispersion medium is selected
from a mineral oil, a synthetic oil and combinations thereof.
15. The method for manufacturing a lubricating oil composition
according to claim 9, wherein an antifoaming agent content in the
lubricating oil composition is 0.01-500 ppm in terms of elemental
fluorine (F) and 0.05-400 ppm in terms of elemental silicon
(Si).
16. The method for manufacturing a lubricating oil composition
according to claim 9, wherein the lubricating oil composition is
for a transmission, for a gear, for gear oil, for a gear box, for
an automotive gear box, for an industrial gear box, or for a
transmission fluid
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Stage of International
Application No. PCT/IB2017/000600 filed on May 19, 2017, which
claims priority to Japanese Patent Application No. 2016-101673
filed on May 20, 2016, the entire contents of which are hereby
incorporated by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a lubricating oil
composition and a method for manufacturing a lubricating oil
composition; more specifically, it relates to a lubricating oil
composition having excellent initial antifoaming performance,
capable of maintaining its antifoaming performance in storage, due
to the use of a specific antifoaming agent dispersion system, and a
method for manufacturing the lubricating oil composition.
BACKGROUND ART
[0003] In order to inhibit foaming during usage and maintain the
various characteristics of lubricating oil, an antifoaming agent
has always been added to the lubricant base oil.
[0004] A method for diluting and dispersing polydimethylsiloxane
having a specific molecular weight, used as an antifoaming agent,
in kerosene or gas oil, and mixing it into the lubricating oil, is
known, and polydimethylsiloxane is considered to be finely
dispersed in lubrication oil (JP 2008-120889 A). A method of
dissolving and dispersing perfluoroalkyl-modified
organopolysiloxane, as an antifoaming agent, in kerosene, and
mixing it into the lubricating oil, is known (JP 2010-116493 A). A
lubricating oil composition, comprising a base oil having high
solubility for additives and polyfluoroalkyl-modified
organopolysiloxane as an antifoaming agent, is known, and a mode
whereby polyfluoroalkylsiloxane is mixed beforehand into a base oil
at approximately 1% by weight, finely dispersed to .ltoreq.10
.mu.m, using a homomixer or a homogenizer, to yield a concentrate,
and then mixed, at a specific quantity, into the base oil, was
disclosed (JP 2000-087069 A). The addition of an antifoaming agent
solution, consisting of a combination of fluorinated silicone, a
specific fluorine-containing organic compound and a
hydrocarbon-based or alcohol-based organic solvent, to the
lubricant base oil, is known (JP 2010-132792 A). A method for
diluting and dispersing perfluoropolyether polysiloxane block
copolymer as an antifoaming agent in kerosene, gas oil or another
organic solvent, adjusting the mean particle size of the block
copolymer to .ltoreq.0.1 .mu.m and adding it to a base oil is
disclosed (JP 2012-062350 A).
SUMMARY
Problem(s) to be Solved
[0005] In recent years there has been progress in lowering the
viscosity of lubricating oil compositions, especially of
lubricating oil compositions for automobiles, such as lubricating
oil compositions for internal combustion engines, lubricating oil
compositions for transmissions and lubricating oil composition for
gears. The problem was, however, that the antifoaming performance
could not be maintained by using existing antifoaming agents. This
is because antifoaming agents are not moderately dispersed in the
lubricant base oil. In order to improve their dispersion,
techniques of dispersing the antifoaming agent in a solvent and
then adding and dispersing it in the lubricant base oil have been
disclosed.
[0006] While dispersion is improved by conventional techniques in
the case of lubricant base oils having somewhat low viscosity, when
the viscosity is decreased in order to further improve the fuel
efficiency, the dispersibility in the lubricant base oil
deteriorates. A new technique of further decreasing viscosity was
therefore sought after.
Means for Solving the Problem(s)
[0007] In light of this problem, the inventors discovered that
antifoaming agents can be well dispersed in lubricating oil
compositions and their antifoaming performance can be improved by
using a specific dispersion medium mixture and mixing it with an
antifoaming agent to obtain an antifoaming agent dispersion system,
which is then mixed with the lubricating oil composition.
[0008] A first embodiment of the present disclosure is a
lubricating oil composition comprising a lubricant base oil and an
antifoaming agent contained in the lubricant base oil, wherein the
lubricating oil composition comprises a lubricant base oil and
drops of an antifoaming agent dispersion system dispersed in the
lubricant base oil; the antifoaming agent dispersion system
comprises a dispersion medium mixture and an antifoaming agent
dispersed in the dispersion medium mixture; and the dispersion
medium mixture comprises a dispersion medium and an additive for
dispersion.
[0009] A second embodiment of the present disclosure is a method
for manufacturing a lubricating oil composition comprising a
lubricant base oil and an antifoaming agent contained in the
lubricant base oil, comprising the steps of mixing a dispersion
medium and an additive for dispersion to prepare a dispersion
medium mixture; mixing an antifoaming agent with the dispersion
medium mixture and dispersing the antifoaming agent in the
dispersion medium mixture to prepare an antifoaming agent
dispersion system; and then dispersing the antifoaming agent
dispersion system in a lubricant base oil.
[0010] A third embodiment of the present disclosure is a method for
preparing an antifoaming agent dispersion system, comprising the
steps of mixing a dispersion medium and an additive for dispersion
to prepare a dispersion medium mixture; and mixing an antifoaming
agent with the dispersion medium mixture to disperse the
antifoaming agent in the dispersion medium mixture.
Effect of the Disclosure
[0011] The lubricating oil composition containing an antifoaming
agent has a high antifoaming performance even when the lubricant
base oil has low viscosity.
DETAILED DESCRIPTION
[0012] The present disclosure will now be described in detail.
[0013] A first embodiment of the present disclosure is a
lubricating oil composition comprising a lubricant base oil and an
antifoaming agent contained in the lubricant base oil, wherein the
lubricating oil composition comprises a lubricant base oil and
drops of an antifoaming agent dispersion system dispersed in the
lubricant base oil; the antifoaming agent dispersion system
comprises a dispersion medium mixture and an antifoaming agent
dispersed in the dispersion medium mixture; and the dispersion
medium mixture comprises a dispersion medium and an additive for
dispersion.
[0014] Some aspects of the first embodiment may be as follows:
[0015] (1) The above-mentioned antifoaming agent is
fluoroalkylpolysiloxane.
[0016] (2) The above-mentioned additive for dispersion is at least
one selected from the group consisting of an ashless dispersant, a
metallic detergent, an antiwear agent, a friction conditioner and
an extreme pressure agent.
[0017] (3) The ashless dispersant, mentioned in (2), is selected
from a succinimide compound, a succinamide compound and
combinations thereof.
[0018] (4) The above-mentioned dispersion medium mixture has a
kinematic viscosity of 5-50,000 mm.sup.2/s at 40.degree. C.
[0019] (5) The above-mentioned dispersion medium is selected from a
mineral oil, a synthetic oil and combinations thereof.
[0020] (6) The antifoaming agent content in the above-mentioned
lubricating oil composition is 0.01-500 ppm in terms of elemental
fluorine (F) and 0.05-400 ppm in terms of elemental silicon
(Si).
[0021] (7) The above-mentioned lubricating oil composition is for a
transmission, for a gear, for gear oil, for a gear box, for an
automotive gear box, for an industrial gear box, or for a
transmission fluid.
[0022] A second embodiment of the present disclosure is a method
for manufacturing a lubricating oil composition comprising a
lubricant base oil and an antifoaming agent contained in the
lubricant base oil, comprising the steps of mixing a dispersion
medium and an additive for dispersion to prepare a dispersion
medium mixture; mixing an antifoaming agent with the dispersion
medium mixture and dispersing the antifoaming agent in the
dispersion medium mixture to prepare an antifoaming agent
dispersion system; and then dispersing the antifoaming agent
dispersion system in a lubricant base oil.
[0023] Some aspects of the second embodiment may be as follows:
[0024] (1) The above-mentioned antifoaming agent is
fluoroalkylpolysiloxane.
[0025] (2) The above-mentioned additive for dispersion is at least
one selected from the group consisting of an ashless dispersant, a
metallic detergent, an antiwear agent, a friction conditioner and
an extreme pressure agent.
[0026] (3) The ashless dispersant, mentioned in (2), is selected
from a succinimide compound, a succinamide compound and
combinations thereof.
[0027] (4) The above-mentioned dispersion medium mixture has a
kinematic viscosity of 5-50,000 mm.sup.2/s at 40.degree. C.
[0028] (5) The above-mentioned dispersion medium is selected from a
mineral oil, a synthetic oil and combinations thereof.
[0029] (6) The antifoaming agent content in the above-mentioned
lubricating oil composition is 0.01-500 ppm in terms of elemental
fluorine (F) and 0.05-400 ppm in terms of elemental silicon
(Si).
[0030] (7) The above-mentioned lubricating oil composition is for a
transmission, for a gear, for gear oil, for a gear box, for an
automotive gear box, for an industrial gear box, or for a
transmission fluid.
[0031] A third embodiment of the present disclosure is a method for
preparing an antifoaming agent dispersion system, comprising the
steps of mixing a dispersion medium and an additive for dispersion
to prepare a dispersion medium mixture; and mixing an antifoaming
agent with the dispersion medium mixture to disperse the
antifoaming agent in the dispersion medium mixture.
[0032] Some aspects of the third embodiment may be as follows:
[0033] (1) The above-mentioned antifoaming agent is
fluoroalkylpolysiloxane.
[0034] (2) The above-mentioned additive for dispersion is at least
one selected from the group consisting of an ashless dispersant, a
metallic detergent, an antiwear agent, a friction conditioner and
an extreme pressure agent.
[0035] (3) The ashless dispersant, mentioned in (2), is selected
from a succinimide compound, a succinamide compound and
combinations thereof.
[0036] (4) The above-mentioned dispersion medium mixture has a
kinematic viscosity of 5-50,000 mm.sup.2/s at 40.degree. C.
[0037] (5) The above-mentioned dispersion medium is selected from a
mineral oil, a synthetic oil and combinations thereof.
[0038] (A) Antifoaming Agent
[0039] An antifoaming agent used in the present disclosure is, but
not limited to, fluoroalkylpolysiloxane.
[0040] Examples of an antifoaming agent include compounds having
any one of the structures of formulas (1) to (5).
##STR00001##
where m+n=8 to 45 and m/n=20 to 100.
##STR00002##
where o=7 to 60.
X--CF.sub.2--O CF.sub.2--CF.sub.2--O .sub.p CF.sub.2--O
.sub.qCH.sub.2--X.sup.1 (3)
where p+q=40 to 180 and p/q=0.5 to 2.
X CF.sub.2--CF.sub.2--CF.sub.2--O .sub.rCF.sub.2--CF.sub.2--X.sup.1
(4)
where r=10 to 50.
[0041] In the above formulas (1) to (4), X and X1 are each
independently selected from
(i) a fluorine atom, and (ii) the group consisting of following (a)
to (g):
(a) --CH.sub.2OH
[0042] (b) --CH.sub.2 (OC.sub.2H.sub.4).sub.tOH (c)
##STR00003##
(d)
##STR00004##
(e) --CH.sub.2COOH
(f) --CF.sub.2COOH
[0043] (g) --CF.sub.2COONH.sub.3-- (CH.sub.2).sub.5--CH.sub.3
##STR00005##
where R is an organic group. An example of the organic group R in
formula (5) is C.sub.xH.sub.2xC.sub.yF.sub.2y+1, where x is an
integer of 1 to 6 and y is an integer of 1 to 14. For m and n,
m:n=95:5 to 0:100. The organic group R may be linear or branched.
In some embodiments y is an integer of 1 to 8, and in some other
embodiments an integer of 1 to 6.
[0044] (B) Dispersion Medium Mixture
[0045] The dispersion medium mixture comprises an additive for
dispersion and a dispersion medium.
[0046] (B1) Dispersion Medium
[0047] The dispersion medium in the dispersion medium mixture is,
but not limited to, a dispersion medium usually used as a lubricant
base oil. In some embodiments, the dispersion medium is selected
from a mineral oil, a synthetic oil and combinations thereof.
[0048] The mineral oil used as a dispersion medium includes, but is
not limited to, paraffinic mineral oils, naphthenic mineral oils,
normal paraffins, isoparrafins, etc., obtained by distilling a
crude oil at a normal atmospheric pressure or under vacuum to
prepare a lubricating oil fraction and subjecting the lubricating
oil fraction to one or more of purification treatments such as
solvent deasphalting, solvent extraction, hydrogenolysis, solvent
dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid
treatment and clay treatment.
[0049] A method for manufacturing the mineral oil includes, but is
not limited to, a method comprising the steps of distilling a crude
oil at a normal atmospheric pressure or under vacuum to obtain a
lubricating oil fraction and subjecting the lubricating oil
fraction to one or more of purification treatments such as solvent
deasphalting, solvent extraction, hydrogenolysis, solvent dewaxing,
catalytic dewaxing, hydrorefining, sulfuric acid treatment and clay
treatment.
[0050] Moreover, a single mineral oil may be used alone, or two or
more mineral oils may be used in combination at any ratio.
[0051] The synthetic oil used as a dispersion medium includes, but
is not limited to, poly-.alpha.-olefins or hydrogenated products
thereof, isobutene oligomers or hydrogenated products thereof,
isoparaffin, alkylbenzene, alkylnaphthalene, diesters (such as
ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate,
ditridecyl adipate and di-2-ethylhexyl sebacate), polyol esters
(such as trimethylolpropane caprylate, trimethylolpropane
pelargonate, pentaerythritol 2-ethylhexanoate and pentaerythritol
pelargonate), polyoxyalkylene glycol, dialkyl diphenyl ether and
polyphenyl ether.
[0052] In some embodiments, the synthetic oil includes
poly-.alpha.-olefin. Examples of poly-.alpha.-olefin include
oligomers or co-oligomers of .alpha.-olefin having 2 to 32 carbon
atoms, 2 to 16 carbon atoms (such as 1-octene oligomer, 1-decene
oligomer and ethylene-propylene oligomer) and hydrogenated products
thereof.
[0053] The method for manufacturing poly-.alpha.-olefin includes,
but is not limited to, .alpha.-olefin polymerization in the
presence of a polymerization catalyst such as a Friedel-Crafts
catalyst including aluminum trichloride, boron trifluoride or a
complex of boron trifluoride with water, an alcohol (such as
ethanol, propanol or butanol), a carboxylic acid or an ester (such
as ethyl or ethyl acetate propionate).
[0054] The kinematic viscosity of the dispersion medium at
100.degree. C. is, but not limited to, from 2 to 1,000 mm.sup.2/s
in some embodiments, from 5 to 500 mm.sup.2/s in some embodiments,
from 10 to 500 mm.sup.2/s in some embodiments and from 20 to 300
mm.sup.2/s in some embodiments.
[0055] (B2) Additive for Dispersion
[0056] In some embodiments, the additive for dispersion is an agent
having a function of raising the viscosity of a mixture of the
dispersion medium and the agent above the viscosity of the
dispersion medium alone when it is mixed with the dispersion
medium. In some embodiments, the additive for dispersion is at
least one selected from the group consisting of an ashless
dispersant, metallic detergent, friction conditioner, antiwear
agent and extreme pressure agent among additives usually added to
lubricating oil, but is not limited to these.
[0057] In some embodiments, the additive for dispersion is an
ashless dispersant. A variety of ashless dispersants may be used.
The ashless dispersant includes, but is not limited to, products
obtained by modifying a nitrogen-containing compound having at
least one linear or branched C.sub.40-400 alkyl or alkenyl group in
one molecule or derivatives thereof or alkenylsuccinimide with
boron, etc. The ashless dispersant also includes products modified
with carboxylic acid, alcohol, aldehyde, ketone or alkylphenol, but
a boron-modified product (hereinafter referred to as a "boronated
ashless dispersant") is specifically used in some embodiments. One
ashless dispersant may be used alone, or two or more ashless
dispersants may be used in combination. The boronated ashless
dispersant is a product obtained by boronating any ashless
dispersant used in lubricating oil. Boronation is generally
conducted by reacting a nitrogen-containing compound with boric
acid to neutralize some or all of the remaining amino groups and/or
imino groups.
[0058] In some embodiments, the carbon number of the above alkyl
group or alkenyl group is from 40 to 400, and in some other
embodiments from 60 to 350. If the carbon number of the alkyl group
or alkenyl group is below the above lower limit, the solubility of
the compound in the lubricant base oil tends to decrease. If, on
the other hand, the carbon number of the alkyl group or alkenyl
group exceeds the above upper limits, the low-temperature fluidity
of the lubricating oil composition tends to deteriorate. The above
alkyl group and alkenyl group may have a straight chain structure
or a branched chain structure. Examples thereof include branched
alkyl groups or branched alkenyl groups, derived from oligomers of
olefin, such as propylene, 1-butene and isobutylene, and
co-oligomers of ethylene and propylene.
[0059] Examples of succinimide include a so-called monotype
succinimide, which is a reaction product of one end of a polyamine
and succinic anhydride, and a so-called bis-type succinimide, which
is a reaction product of both ends of polyamine and succinic
anhydride. The lubricating oil composition of the present
disclosure may contain either the monotype or the bis-type, or it
may contain both.
[0060] The above modified alkenylsuccinimide may be, for example, a
product obtained by modifying a succinimide compound containing an
alkenyl group with a boron compound (hereinafter referred to as
"boronated succinimide"). One boronated succinimide may be used
alone, or two or more boronated succinimides may be used in
combination. A boronated succinimide and an unboronated succinimide
may be used in combination, and a combination of two or more types
of boronated succinimide may be used. Furthermore, combined use of
a monotype and a bis-type, combined use of two monotypes or
combined use of two bis-types is possible.
[0061] Examples of a method for manufacturing a boronated
succinimide include methods disclosed in Japanese Examined Patent
Publication Nos. S42-8013 and S42-8014, Japanese Unexamined Patent
Publication Nos. S51-52381 and S51-130408, etc. Specifically, it
can be obtained, for example, by mixing polyamine,
polyalkenylsuccinic acid or anhydride, and a boron compound such as
boric acid, borate ester or borate salt with an organic solvent
such as alcohols, hexane or xylene, a light lubricant base oil,
etc., and heat-treating them. The boron content of the boronated
succinimide, obtained in this way, can usually be from 0.1 to 4% by
weight. A boron-modified alkenylsuccinimide compound, such as a
boronated succinimide in some embodiments, may have superior heat
resistance, oxidation resistance and wear prevention.
[0062] The boron content of the boronated ashless dispersant is,
but not limited to, 0.1 to 3% by weight based on the weight of the
ashless dispersant. In some embodiments, the boron content of the
ashless dispersant is not less than 0.2% by weight, in some
embodiments not less than 0.4% by weight, and in some embodiments
not more than 2.5% by weight, in some embodiments not more than
2.0% by weight and in some embodiments not more than 1.5% by
weight. In some embodiments, the boronated ashless dispersant is
boronated succinimide, and in some embodiments is boronated
bis-succinimide.
[0063] In some embodiments, the boronated ashless dispersant has a
boron/nitrogen weight ratio (B/N ratio) of not less than 0.1, in
some embodiments not less than 0.2, and in some embodiments less
than 1.0, and in some embodiments not more than 0.8.
[0064] In some embodiments, a metallic detergent may also be used
as the additive for dispersion in the dispersion medium mixture. An
example of a metallic detergent is a detergent containing an alkali
metal or an alkaline earth metal.
[0065] Examples of alkali metals and alkaline earth metals include,
but are not limited to, magnesium, barium, sodium and calcium.
[0066] Examples of the metallic detergent include, but are not
limited to, sulfonates containing an alkali metal or an alkaline
earth metal, salicylates containing an alkali metal or an alkaline
earth metal, and phenates containing an alkali metal or an alkaline
earth metal.
[0067] Examples of a sulfonate containing an alkali metal or an
alkaline earth metal include, but are not limited to, calcium
sulfonate and magnesium sulfonate.
[0068] Examples of a salicylate containing an alkali metal or an
alkaline earth metal include, but are not limited to, calcium
salicylate and magnesium salicylate.
[0069] Examples of a phenate containing an alkali metal or an
alkaline earth metal include, but are not limited to, calcium
phenate and magnesium phenate.
[0070] The content of the alkali metal or an alkaline earth metal
in the metallic detergent is, but is not limited to, from 0.1 to
20% by weight, in some embodiments from 0.5 to 15% by weight and in
some embodiments from 1.0 to 15% by weight. The metallic detergent
has a total base number of, but not limited to, from 10 to 500
mgKOH/g, in some embodiments from 50 to 400 mgKOH/g and in some
embodiments from 150 to 400 mgKOH/g.
[0071] An antiwear agent may also be used as the additive for
dispersion in the dispersion medium mixture. A variety of antiwear
agents may be used.
[0072] In some embodiments, the antiwear agent is a
phosphorus-containing antiwear agent. For example, zinc
dithiophosphate (ZnDTP, also referred to as "ZDDP"), represented by
following formula (6), may be used.
##STR00006##
In formula (6), R.sup.1 and R.sup.2 may be different or the same,
and are a hydrogen atom or a C.sub.1-26 monovalent hydrocarbon
group. Examples of a monovalent hydrocarbon group include a
C.sub.1-26 primary or secondary alkyl group; a C.sub.2-26 alkyenyl
group; a C.sub.6-26 cycloalkyl group; a C.sub.6-26 aryl group,
alkylaryl group or arylalkyl group; or a hydrocarbon group
containing an ester bond, ether bond, alcohol group or a carboxyl
group. In some embodiments, R.sup.1 and R.sup.2 may be a C.sub.2-12
primary or secondary alkyl group, C.sub.8-18 cycloalkyl group or
C.sub.818 alkylaryl group, and they may be different or the same.
In some embodiments, the antiwear agent is Zinc
dialkyldithiophosphate, and in some embodiments the primary alkyl
group has 3 to 12 carbon atoms, and in some embodiments 4 to 10
carbon atoms. In some embodiments, the secondary alkyl group has 3
to 12 carbon atoms, and in some embodiments 3 to 10 carbon atoms.
Zinc dialkyldithiophosphate having a secondary alkyl group may be
used to increase the torque reduction rate. One of the
above-mentioned zinc thiophosphates may be used alone or two or
more thereof may be used in mixture. Moreover, zinc dithiocarbamate
(ZnDTC) may be used in combination therewith.
[0073] In some embodiments, at least one compound selected from
phosphate- and phosphite-based phosphorus compounds represented by
formulas (7) and (8) below and metal salts and amine salts thereof
may be used.
##STR00007##
In formula (7), R.sup.3 is a C.sub.1-30 monovalent hydrocarbon
group, R.sup.4 and R.sup.5 are each independently a hydrogen atom
or a C.sub.1-30 monovalent hydrocarbon group, and m is 0 or 1.
##STR00008##
In formula (8), R.sup.6 is a C.sub.1-30 monovalent hydrocarbon
group, R.sup.7 and R.sup.8 are each independently a hydrogen atom
or a C.sub.1-30 monovalent hydrocarbon group, and n is 0 or 1.
[0074] Examples of the C.sub.1-30 monovalent hydrocarbon group
represented by R.sup.3 to R.sup.8 in formulas (7) and (8) include
an alkyl group, cycloalkyl group, alkenyl group, alkyl-substituted
cycloalkyl group, aryl group, alkyl-substituted aryl group and
arylalkyl group. In some embodiments, it is a C.sub.1-30 alkyl
group or a C.sub.6-24 aryl group, in some embodiments it is a
C.sub.3-18 alkyl group, and in some embodiments it is a C.sub.4-15
alkyl group.
[0075] Examples of the phosphorus compound represented by formula
(7) include monoesters of phosphorous acid and
hydrocarbylphosphonous acids having one of the above C.sub.1-30
hydrocarbon groups; diesters of phosphorous acid, diesters of
monothiophosphorous acid and monoesters of hydrocarbylphosphonous
acid having two of the above C.sub.1-30 hydrocarbon groups;
triesters of phosphorous acid and diesters of
hydrocarbylphosphonous acid having three of the above C.sub.1-30
hydrocarbon groups; and mixtures thereof.
[0076] Metal salts or amine salts of the phosphorus compounds
represented by formulas (7) or (8) can be obtained by reacting the
phosphorus compounds represented by formulas (7) and (8) with a
metallic base, such as a metal oxide, metal hydroxide, metal
carbonate, and metal chloride, a nitrogen compound, such as
ammonia, and an amine compound having, in its molecule, only a
C.sub.1-30 hydrocarbon group or a hydroxyl group-containing
hydrocarbon group, or the like, and neutralizing part or all of the
remaining acidic hydrogen. Examples of a metal in the
above-mentioned metallic base include an alkali metal such as
lithium, sodium, potassium, and cesium; an alkaline earth metal
such as calcium, magnesium, and barium; a heavy metal such as zinc,
copper, iron, lead, nickel, silver, and manganese (except for
molybdenum). Of these, an alkaline earth metal, such as calcium and
magnesium, and zinc is used in some embodiments, and zinc is used
in some embodiments.
[0077] A friction conditioner may also be used as the additive for
dispersion in the dispersion medium mixture. Examples of the
friction conditioner include, but are not limited to, a
molybdenum-based friction conditioner. Moreover, friction
conditioners other than a molybdenum-based friction conditioner may
also be used, and examples thereof include ester-based friction
conditioners, amine-based friction conditioners and ether-based
friction conditioners.
[0078] A variety of molybdenum-based friction conditioners can be
used. Examples of a molybdenum-based friction conditioner include,
but are not limited to, sulfur-containing organomolybdenum
compounds such as molybdenum dithiophosphate (MoDTP) and molybdenum
dithiocarbamate (MoDTC); complexes of a molybdenum compound with a
sulfur-containing organic compound or another organic compound;
complexes of sulfur-containing molybdenum compounds, such as
molybdenum sulfide andsulfurized molybdenum acid, with
alkenylsuccinimide; etc. Examples of the above molybdenum compounds
include molybdenum oxides such as molybdenum dioxide and molybdenum
trioxide; molybdic acids such as orthomolybdic acid, paramolybdic
acid, and molybdic acid (poly)sulfide; salts of molybdic acid such
as metal salts and ammonium salts of the above molybdic acids;
molybdenum sulfides such as molybdenum disulfide, molybdenum
trisulfide, molybdenum pentasulfide, and molybdenum polysulfide;
molybdic sulfide acid; metal salts or amine salts of sulfurized
molybdic acid; molybdenum halides such as molybdenum chloride; etc.
Examples of the above sulfur-containing organic compounds include
alkyl(thio)xanthate, thiadiazole, mercaptothiadiazole,
thiocarbonate, tetrahydrocarbylthiuram disulfide,
bis(di(thio)hydrocarbyl dithiophosphonate) disulfide,
organo(poly)sulfide, sulfurized esters, etc. Organomolybdenum
compounds such as molybdenum dithiophosphate (MoDTP) and molybdenum
dithiocarbamate (MoDTC) are used in some embodiments.
[0079] Molybdenum dithiocarbamate (MoDTC) is a compound represented
by following formula [I] and molybdenum dithiophosphate (MoDTP) is
a compound represented by following formula [II].
##STR00009##
[0080] In formulas [I] and [II], R.sub.1 to R.sub.8 may be
different or the same, and are a C.sub.1-30 monovalent hydrocarbon
group. The hydrocarbon group may be linear or branched. Examples of
the monovalent hydrocarbon group include a C.sub.1-30 linear or
branched alkyl group; a C.sub.2-30 alkyenyl group; a
C.sub.4-30cycloalkyl group; a C.sub.6-30 aryl group, alkylaryl
group or arylalkyl group; etc. In the arylalkyl group, the aryl may
bond to any position of the alkyl group. In the alkylaryl group,
the alkyl may bond to any position of the aryl group. More
specifically, examples of the alkyl group include a methyl group,
ethyl group, propyl group, butyl group, pentyl group, hexyl group,
heptyl group, octyl group, nonyl group, decyl group, undecyl group,
dodecyl group, tridecyl group, tetradecyl group, pentadecyl group,
hexadecyl group, heptadecyl group, octadecyl group, etc., and
branched alkyl groups thereof, and some embodiments include a
C.sub.3-8 alkyl group. Moreover, X.sub.1 and X.sub.2 are oxygen
atoms or sulfur atoms, and Y.sub.1 and Y.sub.2 are oxygen atoms or
sulfur atoms.
[0081] In addition, organomolybdenum compounds not containing
sulfur may also be used. Examples of such compounds include
molybdenum-amine complexes, molybdenum-succinimide complexes,
molybdenum salts of organic acids, molybdenum salts of alcohols,
etc.
[0082] An extreme pressure agent may also be used as the additive
for dispersion in the dispersion medium mixture. An extreme
pressure agent is, but not limited to, at least one extreme
pressure agent selected from the group consisting of
phosphorus-based extreme pressure agent, sulfur-based extreme
pressure agent and phosphorus-sulfur-based extreme pressure
agent.
[0083] Examples of phosphorus-based extreme pressure agents include
phosphoric acid, phosphorous acid, and phosphates and phosphites
having a C.sub.2-30, phosphates and phosphites having a C.sub.3-20
hydrocarbon group, and salts thereof.
[0084] Examples of sulfur-based extreme pressure agents include
sulfurized oils and fats, sulfurized olefins, dihydrocarbyl
polysulfides, dithiocarbamates, thiadiazoles and
benzothiazoles.
[0085] Moreover, examples of phosphorus-sulfur-based extreme
pressure agents include thiophosphoric acid, thiophosphorous acid,
thiophosphates and thiophosphites having a C.sub.2-30,
thiophosphates and thiophosphites having a C.sub.3-20 hydrocarbon
group, and salts thereof, and zinc dithiophosphate.
[0086] Examples of suitably used extreme pressure agents include at
least one phosphorus-based extreme pressure agent selected from
phosphorous acid, monoesters of phosphorous acid, diesters of
phosphorous acid, triesters of phosphorous acid and salts thereof;
at least one sulfur-based extreme pressure agent selected from
sulfurized fats and oils, olefin sulfides, dihydrocarbyl
polysulfides, dithiocarbamates, thiadiazoles and benzothiazoles;
and/or at least one phosphorus-sulfur-based extreme pressure agent
selected from thiophosphorous acid, monoesters of thiophosphorous
acid, diesters of thiophosphorous acid, triesters of
thiophosphorous acid, dithiophosphorous acid, monoesters of
dithiophosphorous acid, diesters of dithiophosphorous acid,
triesters of dithiophosphorous acid, trithiophosphorous acid,
monoesters of trithiophosphorous acid, diesters of
trithiophosphorous acid, triesters of trithiophosphorous acid, and
salts thereof.
[0087] Examples of the above-mentioned C.sub.2-30 hydrocarbon group
include an alkyl group, cycloalkyl group, alkylcycloalkyl group,
alkenyl group, aryl group, alkylaryl group and arylalkyl group.
[0088] Examples of the alkyl group include ethyl group, propyl
group, butyl group, pentyl group, hexyl group, heptyl group, octyl
group, nonyl group, decyl group, undecyl group, dodecyl group,
tridecyl group, tetradecyl group, pentadecyl group, hexadecyl
group, heptadecyl group, octadecyl group, etc. These alkyl groups
may be linear or branched.
[0089] Examples of the cycloalkyl group include a C.sub.5-7
cycloalkyl group such as a cyclopentyl group, cyclohexyl group, and
cycloheptyl group.
[0090] Examples of the alkylcycloalkyl group include a C.sub.6-11
alkylcycloalkyl group such as methylcyclopentyl group,
dimethylcyclopentyl group, methylethylcyclopentyl group,
diethylcyclopentyl group, methylcyclohexyl group,
dimethylcyclohexyl group, methylethylcyclohexyl group,
diethylcyclohexyl group, methylcycloheptyl group,
dimethylcycloheptyl group, methylethylcycloheptyl group and
diethylcycloheptyl group. The alkyl group(s) may bond to any
position on the cycloalkyl group.
[0091] Examples of the alkenyl group include a butenyl group,
pentenyl group, hexenyl group, heptenyl group, octenyl group,
nonenyl group, decenyl group, undecenyl group, dodecenyl group,
tridecenyl group, tetradecenyl group, pentadecenyl group,
hexadecenyl group, heptadecenyl group and octadecenyl group. These
alkenyl groups may be linear or branched, and the double bond may
exist at any position of the group.
[0092] Examples of the aryl group include a phenyl group, naphthyl
group, etc.
[0093] Examples of the alkylaryl group include a C.sub.7-18
alkylaryl group such as a tolyl group, xylyl group, ethylphenyl
group, propylphenyl group, butylphenyl group, pentylphenyl group,
hexylphenyl group, heptylphenyl group, octylphenyl group,
nonylphenyl group, decylphenyl group, undecylphenyl group and
dodecylphenyl group. The alkyl group may be linear or branched, and
may bond to any position of the aryl group.
[0094] Examples of the arylalkyl group include a C.sub.7-12
arylalkyl group such as a benzyl group, phenylethyl group,
phenylpropyl group, phenylbutyl group, phenylpentyl group, and
phenylhexyl group. The alkyl group may be linear or branched.
[0095] Concrete examples of the phosphorus-based extreme pressure
agent include monobutyl phosphate, monooctyl phosphate, monolauryl
phosphate, dibutyl phosphate, dioctyl phosphate, dilauryl
phosphate, tributyl phosphate, trioctyl phosphate, trilauryl
phosphate, triphenyl phosphate; monobutyl phosphite, monooctyl
phosphite, monolauryl phosphite, dibutyl phosphite, dioctyl
phosphite, dilauryl phosphite, tributyl phosphite, trioctyl
phosphite, trilauryl phosphite, triphenyl phosphite; and salts
thereof. Some embodiments use phosphite-based extreme pressure
agents, and some embodiments use extreme pressure agents based on
diester of phosphorous acid.
[0096] Concrete examples of the phosphorus-sulfur-based extreme
pressure agent include monobutyl thiophosphate, monooctyl
thiophosphate, monolauryl thiophosphate, dibutyl thiophosphate,
dioctyl thiophosphate, dilauryl thiophosphate, tributyl
thiophosphate, trioctyl thiophosphate, triphenyl thiophosphate,
trilauryl thiophosphate; monobutyl thiophosphite, monooctyl
thiophosphite, monolauryl thiophosphite, dibutyl thiophosphite,
dioctyl thiophosphite, dilauryl thiophosphite, tributyl
thiophosphite, trioctyl thiophosphite, triphenyl thiophosphite,
trilauryl thiophosphite having one to three, two to three, or three
sulfur atoms per molecule; and salts thereof. Some embodiments use
thiophosphite-based extreme pressure agents, and some embodiments
use trithiophosphite-based extreme pressure agents.
[0097] Moreover, examples of salts of (thio)phosphates and
(thio)phosphites include salts obtained by reacting a
(thio)phosphate monoester, (thio)phosphate diester, (thio)phosphite
monoester, (thio)phosphite diester, etc., with a nitrogen compound
such as ammonia and an amine compound containing only a C.sub.1-8
hydrocarbon group or hydroxyl-containing hydrocarbon group in its
molecule, or a metallic base such as zinc oxide and zinc chloride
to neutralize part or all of the remaining acidic hydrogen.
[0098] Specific examples of the above nitrogen compound include
ammonia; alkylamines, in which the alkyl group may be linear or
branched, such as monomethylamine, monoethylamine, monopropylamine,
monobutylamine, monopentylamine, monohexylamine, monoheptylamine,
monooctylamine, dimethylamine, methylethylamine, diethylamine,
methylpropylamine, ethylpropylamine, dipropylamine,
methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine,
dipentylamine, dihexylamine, diheptylamine, and dioctylamine;
alkanolamines, in which the alkanol group may be linear or
branched, such as monomethanolamine, monoethanolamine,
monopropanolamine, monobutanolamine, monopentanolamine,
monohexanolamine, monoheptanolamine, monooctanolamine,
monononanolamine, dimethanolamine, methanolethanolamine,
diethanolamine, methanolpropanolamine, ethanolpropanolamine,
dipropanolamine, methanolbutanolamine, ethanolbutanolamine,
propanolbutanolamine, dibutanolamine, dipentanolamine,
dihexanolamine, diheptanolamine, and dioctanolamine; and mixtures
thereof.
[0099] Examples of sulfurized fats and oils include oils such as
sulfurized lard, sulfurized rapeseed oil, sulfurized castor oil,
sulfurized soybean oil, and sulfurized rice bran oil; fatty acid
disulfide such as oleic acid sulfide; and sulfurized esters such as
sulfurized methyl oleate.
[0100] Examples of olefin sulfides include compounds represented by
following formula (9).
R.sup.11--S.sub.x--R.sup.12 (9)
In formula (9), R.sup.11 is a C.sub.2-15 alkenyl group, R.sup.12 is
a C.sub.2-15 alkyl group or alkenyl group, and x is an integer of 1
to 8.
[0101] This compound can be obtained by reacting a C.sub.2-15
olefin or a dimer, trimer or tetramer thereof with a sulfurizing
agent such as sulfur and sulfur chloride. Examples of the olefin
include propylene, isobutene and diisobutene.
[0102] Dihydrocarbyl polysulfide is a compound represented by
following formula (10).
R.sup.13--S.sub.y--R.sup.14 (10)
In formula (10), R.sup.13 and R.sup.14 represent each independently
a C.sub.1-20 alkyl group (including cycloalkyl group), a C.sub.6-20
aryl group and a C.sub.7-20 arylalkyl group, and they may be
different or the same, and y is an integer of 2 to 8.
[0103] Examples of R.sup.13 and R.sup.14 include a methyl group,
ethyl group, n-propyl group, isopropyl group, n-butyl group,
isobutyl group, sec-butyl group, tert-butyl group, various pentyl
groups, various hexyl groups, various heptyl groups, various octyl
groups, various nonyl groups, various decyl groups, various dodecyl
groups, cyclohexyl group, phenyl group, naphthyl group, tolyl
group, xylyl group, benzyl group, phenethyl group, etc.
[0104] Examples of dihydrocarbyl polysulfide include dibenzyl
polysulfide, di-tert-nonyl polysulfide, didodecyl polysulfide,
di-tert-butyl polysulfide, dioctyl polysulfide, diphenyl
polysulfide, dicyclohexyl polysulfide, etc.
[0105] Regarding the weight ratio of the additive for dispersion to
the dispersion medium in the dispersion medium mixture, in some
embodiments the dispersion medium mixture comprises, but not
limited to, 5 to 95% by weight of the additive for dispersion and
95 to 5% by weight of the dispersion medium, in some embodiments 10
to 90% by weight of the additive for dispersion and 90 to 10% by
weight of the dispersion medium, and in some embodiments 20 to 80%
by weight of the additive for dispersion and 80 to 20% by weight of
the dispersion medium.
[0106] The dispersion medium mixture can be obtained by mixing and
stirring the dispersion medium with the additive for dispersion at
a temperature within the range of 30 to 80.degree. C. Into the
dispersion medium mixture obtained in this way, an antifoaming
agent is added at a quantity of 0.1 to 10% by weight, and in some
embodiments 0.3 to 2% by weight, and dispersed using a homogenizer
or a nozzle injector. Since the kinematic viscosity of the
dispersion medium mixture has increased, the antifoaming agent
disperses better than when an antifoaming agent is dispersed in a
solvent such as kerosene.
[0107] In some embodiments, when a homogenizer is used, they are
stirred at a high-speed rotation of 8,000 to 24,000 rpm for 1 to 15
minutes, and in some embodiments at 15,000 to 20,000 rpm for 5 to
10 minutes, but the rotating speed and stirring duration are not
limited to these.
[0108] When a nozzle injector is used, the liquid pressure and the
liquid flow rate are not limited. In some embodiments, the liquid
pressure is from 30 MPa to 200 MPa, and in some embodiments from
100 MPa to 200 MPa.
[0109] In other words, provided is a method for producing an
antifoaming agent dispersion system, comprising the steps of mixing
an antifoaming agent with a dispersion medium mixture comprising an
additive for dispersion and a dispersion medium, and dispersing the
antifoaming agent in the dispersion medium mixture using a
homogenizer or a nozzle injector.
[0110] Thus, the initial dispersion performance and the dispersion
performance after storage of the antifoaming agent in the
dispersion medium mixture are increased.
[0111] Moreover, when a lubricating oil composition is made using
the antifoaming agent dispersion system, the dispersion performance
of the antifoaming agent in the lubricating oil composition is good
not only initially but also after long-term storage.
[0112] The lubricating oil composition of the present disclosure
can be suitably used as lubricating oil compositions for an
automobile, such as lubricating oil compositions for internal
combustion engines, lubricating oil compositions for transmissions
and lubricating oil composition for gears. The lubricating oil
composition for transmissions can be used for any of non-stage
transmission oil, stage transmission oil and motor speed changer
oil.
[0113] (C) Lubricant Base Oil
[0114] In some embodiments, the lubricant base oil used in a
lubricating oil composition is selected from, but not limited to,
mineral oils, synthetic oils and combinations thereof.
[0115] The mineral oil used as a lubricant base oil include, but
not limited to, paraffinic, naphthenic and other mineral oils and
normal paraffin, isoparrafin, etc., obtained by distilling crude
oil at a normal atmospheric pressure or under vaccum to obtain a
lubricating oil distillate fraction and purifying the lubricating
oil distillate fraction by use of one or a combination of two or
more of purification treatments such as solvent deasphalting,
solvent extraction, hydrogenolysis, solvent dewaxing, catalytic
dewaxing, hydrorefining, sulfuric acid treatment and clay
treatment.
[0116] An example of a method for manufacturing the mineral oil
includes, but is not limited to, a method comprising the steps of
distilling crude oil at a normal atmospheric pressure or under
vacuum to obtain a lubricating oil fraction; and purifying the
lubricating oil fraction by use of one or a combination of two or
more of purification treatments such as solvent deasphalting,
solvent extraction, hydrogenolysis, solvent dewaxing, catalytic
dewaxing, hydrorefining, sulfuric acid treatment and clay
treatment.
[0117] Moreover, one of these mineral oils may be used alone, or
two or more thereof may be used in combination at any ratio.
[0118] The synthetic oil used as a lubricant base oil includes, but
not limited to, poly-.alpha.-olefins or hydrogenated products
thereof, isobutene oligomers or hydrogenated products thereof,
isoparaffin, alkylbenzene, alkylnaphthalene, diesters (such as
ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate,
ditridecyl adipate and di-2-ethylhexyl sebacate), polyol esters
(such as trimethylolpropane caprylate, trimethylolpropane
pelargonate, pentaerythritol 2-ethylhexanoate and pentaerythritol
pelargonate), polyoxyalkylene glycol, dialkyl diphenyl ether,
polyphenyl ether, etc.
[0119] In some embodiments, a synthetic oil includes
poly-.alpha.-olefin. Typical examples of poly-.alpha.-olefin
include oligomers or co-oligomers of .alpha.-olefins having 2 to 32
carbon atoms, oligomers or co-oligomers of .alpha.-olefins having 2
to 16 carbon atoms (such as 1-octene oligomer, 1-decene oligomer
and ethylene-propylene oligomer) and hydrogenated products
thereof.
[0120] An example of a method of manufacturing poly-.alpha.-olefin
include, but are not limited to, a method comprising the step of
polymerizing .alpha.-olefin in the presence of a polymerization
catalyst such as a Friedel-Crafts catalyst including aluminum
trichloride, boron trifluoride or a complex of boron trifluoride
with water, an alcohol (such as ethanol, propanol or butanol), a
carboxylic acid or an ester (such as ethyl acetate or ethyl
propionate).
[0121] One of these synthetic oils may be used alone, or two or
more synthetic oils may be used in combination at any ratio.
[0122] Moreover, the above mineral oil(s) and synthetic oil(s) may
be used in combination at any ratio, wherein one mineral or
synthetic oil may be used, or two or more mineral or synthetic oils
may be used.
[0123] The kinematic viscosity of the lubricant base oil at
100.degree. C. is, but not limited to, from 1 to 300 mm.sup.2/s, in
some embodiments from 1 to 100 mm.sup.2/s, in some embodiments from
1 to 50 mm.sup.2/s and in some embodiments from 1 to 30
mm.sup.2/s.
[0124] (D) Additives to the Lubricant Base Oil
[0125] In addition to the antifoaming agent, a variety of additives
may be added to the lubricant base oil.
[0126] Examples of the additive include, but are not limited to, an
ashless dispersant, metallic detergent, antiwear agent, friction
conditioner, extreme pressure agent, viscosity index improver,
metal deactivator, pour point depressant, antioxidant, etc.
[0127] A variety of ashless dispersants, metallic detergents,
antiwear agents, friction conditioners and extreme pressure agents
may be used, and no particular restrictions are placed on it.
Specifically, the additives for dispersion described above may be
suitably used.
[0128] Examples of a viscosity index improver include
polymethacrylate, dispersed polymethacrylate, olefin copolymer
(polyisobutylene, ethylene-propylene copolymer), dispersed olefin
copolymer, polyalkylstyrene, hydrogenated styrene-butadiene
copolymer, styrene-maleic anhydride ester copolymer, star isoprene,
etc. In addition, a comb polymer, whose backbone comprises at least
a repeating unit based on polyolefin macromer and a repeating unit
based on alkyl (meth)acrylate having a C.sub.1-30 alkyl group, can
be also used.
[0129] Examples of a metal deactivator include imidazoline,
pyrimidine derivatives, alkylthiadiazole, mercaptobenzothiazole,
benzotriazole or derivatives thereof, 1,3,4-thiadiazole
polysulfide, 1,3,4-thiadiazolyl-2,5-bis-dialkyl dithiocarbamate,
2-(alkyldithio)benzimidazole,
.beta.-(o-carboxybenzylthio)propiononitrile, etc.
[0130] As a pour point depressant, for example, a
polymethacrylate-based polymer that suits a used lubricant base
oil, etc. can be used.
[0131] Examples of an antioxidant include phenol-based or
amine-based ashless antioxidants, and metal-based antioxidants such
as copper-based and molybdenum-based antioxidants. Examples of
phenol-based ashless antioxidants include
4,4'-methylene-bis(2,6-di-tert-butylphenol),
4,4'-bis(2,6-di-tert-butylphenol), isooctyl
3-(3,5-di-t-butyl-4-hydroxyphenyl)proprionate, and the like.
Examples of amine-based ashless antioxidants include
phenyl-.alpha.-naphthylamine, alkylphenyl-.alpha.-napthylamine,
dialkyldiphenylamine, etc.
[0132] These additives may be suitably added according to the
intended usage. The quantity added depends on the usage, but in
some embodiments is from 0 to 20% by weight of the lubricating oil
composition.
[0133] A lubricating oil composition is provided by mixing an
antifoaming agent with a dispersion medium mixture consisting of an
additive for dispersion and a dispersion medium, and dispersing the
antifoaming agent in the dispersion medium mixture using a
homogenizer or a nozzle injector to form an antifoaming agent
dispersion system, and mixing the antifoaming agent dispersion
system with a lubricant base oil.
[0134] Moreover, a method of manufacturing a lubricating oil
composition, comprising mixing an antifoaming agent with a
dispersion medium mixture consisting of an additive for dispersion
and a dispersion medium, and dispersing the antifoaming agent in
the dispersion medium mixture using a homogenizer or a nozzle
injector to form an antifoaming agent dispersion system, and mixing
the antifoaming agent dispersion system with a lubricant base oil,
is provided.
EXAMPLES
[0135] Embodiments of the present disclosure will now be explained
by means of examples and comparative examples.
[0136] Lubricating oil compositions for transmissions are
illustrated in the following examples, but the present disclosure
is not limited to or by these examples.
Example 1
[0137] FA-630.RTM. (Shin-Etsu Chemical Co., Ltd.), which is one of
fluoroalkylpolysiloxanes, was used as an antifoaming agent. Its
structure is as follows:
##STR00010##
where R is C.sub.xH.sub.2xC.sub.yF.sub.2y+1.
[0138] 49.5 parts by weight of poly-.alpha.-olefin oil having a
kinematic viscosity at 100.degree. C. of 100 mm.sup.2/s used as a
dispersion medium, and 49.5 parts by weight of
polybutenylsuccinimide having a molecular weight of the polybutenyl
group of 3000, a nitrogen content of 2.0% by weight, and a boron
content of 1.0% by weight, which is an ashless dispersant used as
an additive for dispersion, were mixed to prepare a dispersion
medium mixture. One part by weight of the above-mentioned
fluoroalkylpolysiloxane was added to the dispersion medium mixture,
and the mixture was jetted at a liquid pressure of 100 MPa, using a
nozzle injector (Nanomizer, Nanofuel Co., Ltd.), to obtain an
antifoaming agent dispersion system, in which the antifoaming agent
was dispersed in the dispersion medium mixture.
[0139] When the antifoaming agent dispersion system was put into a
beaker and left to stand for one week, no precipitation of the
antifoaming agent was observed.
[0140] To a mineral oil having a kinematic viscosity of 15
mm.sup.2/s at 40.degree. C. used as a lubricant base oil, an
additive package for ATF (T4278 of Infineum Co.) was added at a
quantity of 10% by weight based on the total weight of the
lubricating oil composition, and the above-mentioned antifoaming
agent dispersion system was added at a quantity of 0.4% by weight,
and the mixture was heated to 60.degree. C. and mixed by stirring,
using a propeller, to prepare a lubricating oil composition.
[0141] 3.3 kg thereof were moved to a 4 L can and the static
stability was evaluated; in the early phase, the whippability was
10 mm, and after 84 days (12 weeks) the whippability remained at 13
mm. In other words, the antifoaming performance was maintained.
[0142] The whippability after 84 days was measured by putting 200
cm.sup.3 of sample into a 500 cm.sup.3 tall beaker, raising the
temperature to 140.degree. C. on a hot plate, stirring it for 5
minutes at 11,600 rpm by use of a homogenizer (manufactured by IKA)
while blowing air at 200 mL/min, and measuring the increase in the
height of the liquid level.
[0143] The lubricating oil composition thus obtained is useful as a
lubricating oil composition for transmissions.
Example 2
[0144] An antifoaming agent dispersion system was obtained using
the same method as in Example 1, except that a homogenizer was used
for dispersion instead of the nozzle injector.
[0145] When the antifoaming agent dispersion system was put into a
beaker and left to stand for one week, no precipitation of the
antifoaming agent was observed. Using the obtained antifoaming
agent dispersion system with the same lubricant base oil and
additive as used in Example 1, a lubricating oil composition was
obtained in the same way as in Example 1. 3.3 kg thereof were moved
to a 4 L can and the static stability was evaluated; in the early
phase, the whippability was 13 mm, and after 84 days (12 weeks) it
remained at 15 mm. In other words, the antifoaming performance was
maintained. The lubricating oil composition thus obtained is useful
as a lubricating oil composition for transmissions.
Comparative Example 1
[0146] Forty (40) parts by weight of fluoroalkylpolysiloxane used
in the above Example 1 was added to 60 parts by weight of kerosene,
and an antifoaming agent dispersion system was obtained in the same
way as in Example 1.
[0147] When put into a beaker and left to stand, precipitation of
the antifoaming agent was observed after 30 minutes, and after one
hour all the antifoaming agent precipitated. For this reason, it
was unsuitable for use as a lubricating oil composition.
[0148] The above results showed that the antifoaming agent
dispersion system used in the present disclosure enables dispersion
of an antifoaming agent without precipitation over a long time. As
the result, it is not necessary to produce a lubricating oil
composition immediately after the production of an antifoaming
agent dispersion system, thus improving the production efficiency
of an lubricating oil composition.
[0149] Moreover, it was found that in the lubricating oil
composition of the present disclosure, the antifoaming performance
of the antifoaming agent is maintained over a long time.
INDUSTRIAL APPLICABILITY
[0150] The lubricating oil composition of the present disclosure
can be used in a wide variety of fields, in which a lubricating oil
is needed. While the above examples relate to lubricating oil
compositions for transmissions, the disclosure is not limited to or
by them; it is applicable to all lubricating oil compositions, and
can be suitably used especially to lubricating oil compositions for
automobiles, more especially to lubricating oil compositions for
internal combustion engines, lubricating oil compositions for
transmissions, and lubricating oil composition for gears. The
lubricating oil composition for transmissions includes non-stage
transmission oil, stage transmission oil and motor speed changer
oil.
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