U.S. patent application number 14/878923 was filed with the patent office on 2016-06-16 for low viscosity gear oil composition providing enhanced fuel efficiency.
The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Sung Uk LEE.
Application Number | 20160168504 14/878923 |
Document ID | / |
Family ID | 56110555 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160168504 |
Kind Code |
A1 |
LEE; Sung Uk |
June 16, 2016 |
LOW VISCOSITY GEAR OIL COMPOSITION PROVIDING ENHANCED FUEL
EFFICIENCY
Abstract
A gear oil composition includes base oil including
poly-alpha-olefin (PAO) synthetic oil in 70 to 95% by weight and
oil-soluble polyalkylene glycol (OSP) synthetic oil in 5 to 30% by
weight based on the weight of the base oil. The gear oil further
includes a polyalkyl methacrylate-based Viscosity modifer in 5 to
20 parts by weight, based on 100 parts by weight of the base
oil.
Inventors: |
LEE; Sung Uk; (Boryeong-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Family ID: |
56110555 |
Appl. No.: |
14/878923 |
Filed: |
October 8, 2015 |
Current U.S.
Class: |
508/505 |
Current CPC
Class: |
C10M 2209/084 20130101;
C10M 2223/045 20130101; C10N 2030/08 20130101; C10M 2209/106
20130101; C10N 2030/02 20130101; C10N 2010/04 20130101; C10N
2020/011 20200501; C10N 2020/02 20130101; C10M 169/041 20130101;
C10M 2223/047 20130101; C10M 2219/08 20130101; C10M 2215/28
20130101; C10N 2040/04 20130101; C10M 111/04 20130101; C10M
2209/1065 20130101; C10M 2205/0285 20130101; C10N 2030/06 20130101;
C10M 2223/04 20130101 |
International
Class: |
C10M 145/14 20060101
C10M145/14 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 2014 |
KR |
10-2014-0177652 |
Claims
1. A gear oil composition comprising: base oil including
poly-alpha-olefin (PAO) synthetic oil in 70 to 95% by weight and
oil-soluble polyalkylene glycol (OSP) synthetic oil in 5 to 30% by
weight based on the weight of the base oil; and a polyalkyl
methacrylate-based Viscosity modifer in 5 to 20 parts by weight,
based on 100 parts by weight of the base oil.
2. The gear oil composition of claim 1, further comprising:
additives in 3 to 20 parts by weight, based on 100 parts by weight
of the base oil.
3. The gear oil composition of claim 1, wherein the
poly-alpha-olefin (PAO) synthetic oil has an average kinematic
viscosity of 3 to 8 cSt at 100.degree. C., a viscosity index of 130
or greater, and a pour point of -50.degree. C. or lower.
4. The gear oil composition of claim 1, wherein the oil-soluble
polyalkylene glycol (OSP) synthetic oil has an average kinematic
viscosity of 6 to 12 cSt at 100.degree. C., a viscosity index of
140 or greater, and a pour point of -40.degree. C. or lower.
5. The gear oil composition of claim 1, wherein the polyalkyl
methacrylate-based Viscosity modifer has a kinematic viscosity of
650 cSt or greater at 100.degree. C.
6. The gear oil composition of claim 1, wherein the polyalkyl
methacrylate-based Viscosity modifer has a number average molecular
weight range of 300,000 to 400,000, and has 4 to 10 C.sub.12 to
C.sub.15 polymer chains.
7. The gear oil composition of claim 6, wherein the C.sub.12 to
C.sub.15 polymer chains include alkyl methacrylate in 60 to 80% by
weight and 2-ethylhexyl methacrylate in 20 to 40% by weight.
8. The gear oil composition of claim 2, wherein the additives are
one or more selected from the group consisting of a
dithiophosphate-based abrasion resistant agent, a calcium-based
detergent and dispersant, a phosphate ester-based friction
modifier, a bis-succinimide-type ashless dispersant, a
polysulfide-based extreme pressure agent, and an anti-oxidant.
9. The gear oil composition of claim 1, having an average kinematic
viscosity of 7 to 11 cSt at 100.degree. C., an average kinematic
viscosity of 30 to 60 cSt at 40.degree. C., and an average absolute
viscosity of 10,000 to 50,000 cP at -40.degree. C.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims under 35 U.S.C. .sctn.119(a) the
benefit of priority to Korean Patent Application No. 1 0-201 4-01
77652 filed on Dec. 10, 2014, the entire contents of which are
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a gear oil composition
having enhanced fuel efficiency and low viscosity. More
particularly, it relates to a gear oil composition having enhanced
fuel efficiency and low viscosity formed with base oil, a Viscosity
modifer and additives, and capable of enhancing fuel efficiency and
durability of vehicles by mixing and using poly-alpha-olefin (PAO)
synthetic oil and oil-soluble polyalkylene glycol (OSP) synthetic
oil in a specific content ratio as the base oil.
BACKGROUND
[0003] In general gear lubrication, engagement of gear is a line
contact and large weight and pressure are applied to the gear, and
therefore, an extreme pressure property is particularly required
for gear oil. In this regard, gear oil has compositional
characteristics in that an extreme pressure agent is included,
which is different from other lubricants. In addition, for gear
oil, viscosity capable of distributing sufficient lubricants to all
friction parts, and capable of forming suitable oil films for the
pressure, the rate and the temperature is required.
[0004] Gear oil has been manufactured using combinations of
petroleum-derived base oil, and as a typical example, Chevron
Tegra.TM. gear oil has been manufactured including highly purified
petroleum-derived Group III base oil and 20% by weight of greater
of a viscosity index improver.
[0005] Prior inventions relating to gear oil are as follows. The
European Patent Application Laid-Open Publication No. 1,570,035
(Patent Document 1) discloses a technology of manufacturing gear
oil having low Brookfield viscosity using base oil having low CCS
viscosity. The U.S. Patent Application Laid-Open Publication No.
2005-0133407 (Patent Document 2) discloses a technology of
manufacturing gear oil having low Brookfield viscosity from
Fischer-Tropsch-derived base oil. The U.S. Patent Application
Laid-Open Publication No. 2005-0258078 (Patent Document 3)
discloses that a mixture of base oil manufactured from high
paraffin wax prepared using Group II or Group III base oil has very
low Brookfield viscosity.
[0006] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
invention and therefore it may contain information that does not
form the prior art that is already known in this country to a
person of ordinary skill in the art.
SUMMARY
[0007] Embodiments of the present invention have been made in an
effort to solve the above-described problems associated with prior
art, and inventors of the present invention have found out that
fuel efficiency and durability of vehicles are simultaneously
enhanced when poly-alpha-olefin (PAO) synthetic oil and oil-soluble
polyalkylene glycol (OSP) synthetic oil are mixed and used in a
specific content ratio as base oil, and a polyester-based Viscosity
modifer and additives are mixed thereto.
[0008] Accordingly, an object of certain embodiments of the present
invention is to provide a gear oil composition having average
kinematic viscosity of 7 to 11 cSt at 100.degree. C., average
kinematic viscosity of 30 to 60 cSt at 40.degree. C., and having
low viscosity of average absolute viscosity of 10,000 to 50,000 cP
at -40.degree. C., and capable of enhancing fuel efficiency of
vehicles by 1 to 2%.
[0009] In certain embodiments, the present invention provides a
gear oil composition including (A) base oil including
poly-alpha-olefin (PAO) synthetic oil in 70 to 95% by weight and
oil-soluble polyalkylene glycol (OSP) synthetic oil in 5 to 30% by
weight, and, based on 100 parts by weight of the base oil, (B) a
polyalkyl methacrylate-based Viscosity modifer in 5 to 20 parts by
weight and, in certain embodiments, (C) additives in 3 to 20 parts
by weight.
[0010] In certain embodiments, the poly-alpha-olefin (PAO)
synthetic oil may have an average kinematic viscosity of 3 to 8 cSt
at 100.degree. C., a viscosity index of 130 or greater, and a pour
point of -50.degree. C. or lower.
[0011] In certain embodiments, the oil-soluble polyalkylene glycol
(OSP) synthetic oil may have an average kinematic viscosity of 6 to
12 cSt at 100.degree. C., a viscosity index of 140 or greater, and
a pour point of -40.degree. C. or lower.
[0012] In certain embodiments, the polyalkyl methacrylate-based
Viscosity modifer may have a kinematic viscosity of 650 cSt or
greater at 100.degree. C.
[0013] In certain embodiments, the polyalkyl methacrylate-based
Viscosity modifer may have a number average molecular weight range
of 300,000 to 400,000, and may have 4 to 10 C.sub.12 to C.sub.15
polymer chains.
[0014] In certain embodiments, the C.sub.12 to C.sub.15 polymer
chains may include alkyl methacrylate in 60 to 80% by weight and
2-ethylhexyl methacrylate in 20 to 40% by weight.
[0015] In certain embodiments, the additives may be one or more
selected from the group consisting of a dithiophosphate-based
abrasion resistant agent, a calcium-based detergent and dispersant,
a phosphate ester-based friction modifier, a bis-succinimide-type
ashless dispersant, a polysulfide-based extreme pressure agent, and
an anti-oxidant.
[0016] In certain embodiments, the gear oil composition may have an
average kinematic viscosity of 7 to 11 cSt at 100.degree. C., an
average kinematic viscosity of 30 to 60 cSt at 40.degree. C., and
an average absolute viscosity of 10,000 to 50,000 cP at -40.degree.
C.
[0017] Other aspects and preferred embodiments of the invention are
discussed infra.
[0018] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicles in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (e.g. fuels derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example both
gasoline-powered and electric-powered vehicles.
DETAILED DESCRIPTION
[0019] Hereinafter reference will now be made in detail to various
embodiments of the present invention, examples of which are
described below. While the invention will be described in
conjunction with exemplary embodiments, it will be understood that
present description is not intended to limit the invention to those
exemplary embodiments. On the contrary, the invention is intended
to cover not only the exemplary embodiments, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
[0020] A gear oil composition according to the present invention
includes (A) base oil, (B) a Viscosity modifer and, in certain
embodiments, (C) additives.
[0021] Each constituent forming the gear oil composition of
embodiments of the present invention is described in more detail as
follows.
(A) Base Oil
[0022] An embodiment of present invention uses a mixture of
poly-alpha-olefin (PAO) synthetic oil and oil-soluble polyalkylene
glycol (OSP) synthetic oil as base oil. In certain embodiments, a
mixture including PAO in 70 to 95% by weight and OSP in 5 to 30% by
weight is used as base oil. In using a mixture of PAO and OSP as
base oil, an effect of enhancing fuel efficiency and durability may
not be expected when the OSP content is less than the
above-mentioned weight ratio, and a problem of additive
precipitation may occur when the OSP content is greater than the
above-mentioned weight ratio and is excessively used.
[0023] In certain embodiments, the poly-alpha-olefin (PAO)
synthetic oil used as the base oil in the present invention may
have an average kinematic viscosity of 3 to 8 cSt at 100.degree.
C., a viscosity index of 130 or greater, and a pour point of
-50.degree. C. or lower.
[0024] In certain embodiments, the poly-alpha-olefin (PAO)
synthetic oil used as the base oil has average kinematic viscosity
of 3 to 8 cSt at 100.degree. C., a viscosity index of 130 to 150,
and a pour point of -70 to -50.degree. C.
[0025] In addition, certain embodiments of the present invention
use oil-soluble polyalkylene glycol (OSP) synthetic oil as the base
oil. Polyalkylene glycol is a polymer copolymerizing an alkylene
oxide such as ethylene oxide (EO), propylene oxide (PO) and
butylene oxide (BO), and the oil-soluble polyalkylene glycol (OSP)
used in the present invention as the base oil is a polymer
copolymerizing butylene oxide, styrene oxide and the like having
higher carbon components than ethylene oxide and propylene oxide,
and has fluidity by having solubility for oil, which is different
from existing polyalkylene glycol. In certain embodiments,
theoil-soluble polyalkylene glycol (OSP) synthetic oil may have an
average kinematic viscosity of 6 to 12 cSt at 100.degree. C., a
viscosity index of 140 or greater, and a pour point of -40.degree.
C. or lower. In certain embodiments, the oil-soluble polyalkylene
glycol (OSP) synthetic oil has average kinematic viscosity of 6 to
12 cSt at 100.degree. C., a viscosity index of 140 to 160, and a
pour point of -60 to -40.degree. C.
[0026] In the poly-alpha-olefin (PAO) synthetic oil and the
oil-soluble polyalkylene glycol (OSP) synthetic oil used as the
base oil in the present invention, when the kinematic viscosity at
100.degree. C. is less than the above-mentioned range, there is a
problem in that gear abrasion may increase, and when the kinematic
viscosity is greater than the above-mentioned range, a viscosity
increase at low temperatures may intensify, which may cause a
problem of operability decline at low temperatures and a fuel
efficiency decrease.
[0027] The gear oil composition of certain embodiments of the
present invention may include a mixture of the poly-alpha-olefin
(PAO) synthetic oil and the oil-soluble polyalkylene glycol (OSP)
synthetic oil in a range of 65 to 90% by weight, and, in certain
embodiments, in a range of 75 to 85% by weight as the base oil.
(B) Viscosity modifer
[0028] In certain embodiment of the present invention, a Viscosity
modifer is included in order to increase viscosity of gear oil, and
increase a viscosity index by suppressing a viscosity increase at
low temperatures. A polyalkyl methacrylate-based Viscosity modifer
may be used as the Viscosity modifer. In certain embodiments, as
the polyalkyl methacrylate-based Viscosity modifer, a polymer
material having a number average molecular weight ranging from
300,000 to 400,000, and having 4 to 10 C.sub.12 to C.sub.15 polymer
chains may be used. In certain embodiments, the C.sub.12 to
C.sub.15 polymer chain may include alkyl methacrylate in 60 to 80%
by weight and 2-ethylhexyl methacrylate in 20 to 40% by weight. In
addition, the polyalkyl methacrylate-based Viscosity modifer may
have a kinematic viscosity of 650 cSt or greater at 100.degree. C.,
and, in certain embodiments, may have a kinematic viscosity of 650
to 1000 cSt at 100.degree. C.
[0029] The gear oil composition of certain embodiments of the
present invention may include the polyalkyl methacrylate-based
Viscosity modifer in a range of 5 to 20 parts by weight, and, in
certain embodiments, in a range of 10 to 15 parts by weight based
on 100 parts by weight of the base oil. When the content of the
Viscosity modifer is small, which is less than 5 parts by weight,
viscosity may not be suitably increased at room temperature and
high temperatures causing an excessive viscosity increase at low
temperatures, and when the content is greater than 15 parts by
weight, viscosity increases both at high temperatures and low
temperatures, and a problem of durability decline may occur due to
a viscosity decrease by shear during a durability progress.
(C) Additives
[0030] In the gear oil composition of the present invention,
additives, which may include additives commonly used in the art,
may be properly selected and added as necessary. Additives approved
of an API GL-5 grade or SAE J 2360 may be used.
[0031] The gear oil composition of the present invention may
include additives out of choice, and the amount of the additives
used is not particularly limited in the present invention. If the
amount is limited nonetheless, the additives may be included in a
range of 3 to 20 parts by weight and, in certain embodiments, in a
range of 5 to 10 parts by weight based on 100 parts by weight of
the base oil.
[0032] In certain embodiments, the additives may include a
dithiophosphate-based abrasion resistant agent, a calcium-based
detergent and dispersant, a phosphate ester-based friction
modifier, a bis-succinimide-type ashless dispersant, a
polysulfide-based extreme pressure agent, or an anti-oxidant.
However, the additives used are not limited to the above
examples.
[0033] The gear oil composition of certain embodiments of the
present invention having constituents and compositions as described
above may have an average kinematic viscosity of 7 to 11 cSt at
100.degree. C., and an average kinematic viscosity of 30 to 60 cSt
at 40.degree. C. It may have low viscosity. For example, its
average absolute viscosity may be 10,000 to 50,000 cP at
-40.degree. C. When comparing to high viscosity oil having average
kinematic viscosity of 13 to 17 cSt at 100.degree. C., average
kinematic viscosity of 60 to 150 cSt at 40.degree. C., and average
absolute viscosity of 50,000 to 200,000 at -40.degree. C. used in
existing gear oil due to a durability problem, the gear oil
composition of the present invention maintains low viscosity, and a
result of enhancing fuel efficiency of vehicles by 1 to 2% is
obtained.
EXAMPLES
[0034] Hereinafter, embodiments of the present invention will be
described in more detail with reference to the following examples.
However, the following examples are for illustrative purposes only,
and the scope of the present invention is not limited thereto.
[0035] Examples 1 to 3 and Comparative Examples 1 to 5.
[0036] Gear oil was prepared using constituents and content ratios
shown in the following Table 1.
TABLE-US-00001 TABLE 1 Gear Oil Composition Example Comparative
Example Category 1 2 3 1 2 3 4 5 Base PAO.sup.1) 95 90 70 100 -- 97
60 90 Oil OSP.sup.2) 5 10 30 -- 100 3 40 10 (% by Weight) Viscosity
10 10 10 10 10 10 10 30 modifer.sup.3) (Parts by Weight)*
Additives.sup.4) (Parts 10 10 10 10 10 10 10 10 by Weight)*
.sup.1)Poly-alpha-olefin, PAO4 manufactured by Eneos (kinematic
viscosity at 100.degree. C.: 3.9 cSt, viscosity index: 130, pour
point: -69.degree. C.) .sup.2)Polyalkylene glycol, OSP-32 product
manufactured by Dow Chemical Company (kinematic viscosity at
100.degree. C.: 6.5 cSt, viscosity index: 146, pour point:
-50.degree. C.) .sup.3)Polyalkyl methacrylate, 0-050 manufactured
by Evonik Industries .sup.4)Additive package: Anglamol 6043
manufactured by Lubrizol Corporation (products approved of an API
GL-5 grade or SAE J2360) *The content of the Viscosity modifer and
the additives is the amount used based on 100 parts by weight of
the base oil written in parts by weight
[0037] For the gear oil prepared according to Examples 1 to 3 and
Comparative Examples 1 to 5, physical properties were measured
using the following methods. The results are shown in the following
Table 2.
[Physical Property Measurement Method]
[0038] (1) Kinematic viscosity measurement method: it was measured
using an ASTM D 445 measurement method.
[0039] (2) Low temperature viscosity measurement method: it was
measured using an ASTM D 2983 measurement method.
[0040] (3) FZG gear durability test: it was measured using an FVA
No.2/IV measurement method.
[0041] (4) Axle delivery efficiency (%) measurement method: a
percentage of power input to a transmission and power output from
the transmission was measured.
TABLE-US-00002 TABLE 2 Target Example Comparative Example Category
Value 1 2 3 1 2 3 4 5 Kinematic 100.degree. C. Lower the 7 9 11 6
Precipitation 7 Precipitation 15 Viscosity Better (cSt) 40.degree.
C. Lower the 30 45 60 28 -- 40 -- 130 Better Low -40.degree. C.
Lower the 10,000 30,000 50,000 10,000 -- 20,000 -- 150,000
Temperature Better Viscosity (cP) FZG Gear Limit (gear) Higher 12
12 12 10 -- 11 -- 12 the Better FZG Gear Durability (hr) Higher 72
72 84 48 -- 48 -- 60 the Better Axle Efficiency Higher 96 97 97 96
-- 96 -- 93 the Better In the compositions in Comparative Example 2
and Comparative Example 4, precipitate production was identified,
and physical properties were not measured.
[0042] As shown from the results in Table 2, durability of
Comparative Example 1 including PAO alone as base oil and
Comparative Example 3 having low OSP content was low compared to
the examples. In addition, precipitation of the additives was
observed in Comparative Example 2 including OSP alone and
Comparative Example 4 excessively using OSP. Furthermore, in
Comparative Example 5, a phenomenon of an excessive kinematic
viscosity increase was identified due to the excess Viscosity
modifer. As a result, it can be seen that a problem of durability
decline or additive precipitation occurs in a gear oil composition
outside the bounds of the content ranges proposed in the present
invention.
[0043] Meanwhile, the gear oil compositions of Examples 1 to 3 had
average kinematic viscosity of 7 to 11 cSt at 100.degree. C. and
average kinematic viscosity of 30 to 60 cSt at 40.degree. C., and
had average absolute viscosity of 10,000 to 50,000 cP at
-40.degree. C.
[0044] According to the results described above, it was identified
that the gear oil composition according to certain embodiments of
the present invention had relatively low viscosity, but was capable
of securing gear durability, and fuel efficiency was enhanced by 1
to 2%.
[0045] Accordingly, the gear oil composition according to the
present invention is particularly effective in improving gear
fitting/scoring by increasing abrasion resistance of a transmission
and an oil film despite having low viscosity, and in enhancing fuel
efficiency as well.
[0046] The gear oil composition according to certain embodiments of
the present invention has average kinematic viscosity of 7 to 11
cSt at 100.degree. C., and average kinematic viscosity of 30 to 60
cSt at 40.degree. C., and average absolute viscosity of 10,000 to
50,000 cP at -40.degree. C.
[0047] The gear oil of the present invention having compositional
characteristics as above has low viscosity compared to existing
gear oil, but has enhanced durability, and is effective in
enhancing fuel efficiency by 1 to 2%.
[0048] The invention has been described in detail with reference to
preferred embodiments thereof. However, it will be appreciated by
those skilled in the art that changes may be made in these
embodiments without departing from the principles and spirit of the
invention, the scope of which is defined in the appended claims and
their equivalents.
* * * * *