Chemistry of hydrocarbon compounds – Compound or reaction product mixture – Alicyclic
Reexamination Certificate
1999-09-16
2001-02-20
McAvoy, Ellen M. (Department: 1764)
Chemistry of hydrocarbon compounds
Compound or reaction product mixture
Alicyclic
C585S020000, C585S022000, C508S110000, C508S591000, C252S073000
Reexamination Certificate
active
06191330
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fluids for traction drives, and more particularly to such traction drive fluids which can be used not only for the driving force transmitting mechanism but also for the hydraulic pressure controlling mechanism and the friction characteristics controlling mechanism of the wet clutch, of the continuously variable transmissions of traction drive type of automobiles.
2. Description of Prior Art
In the field of industrial machines, traction drive fluids have already been used in traction drive type power transmitting apparatuses which transmit power via the film of the traction drive fluids. Such traction drive fluids are required to be high in traction coefficient which indicates power transmission capability.
In recent years, extensive studies and investigations on a traction drive fluid have progressed for its use of continuously variable transmissions of automobiles. The traction drive fluids to be used for an automobile are expected to be used not only in the power transmitting mechanism but also in the hydraulic controlling mechanism and the friction characteristics controlling mechanism for the wet clutch thereof.
Automatic transmission fluid (ATF) is known as a lubricant used for the hydraulic controlling mechanism of the transmission of an automobile and the friction characteristics controlling mechanism of the wet clutch of the same. It is a well-known fact that such ATF is required to be higher in a kinematic viscosity at elevated temperatures than a certain level and superior in flowability at low temperatures for performing the role of the hydraulic controlling mechanism. It is also well known that ATF needs to be blended with additives which are excelled in friction characteristics, particularly in anti-shudder characteristics for fulfilling requirements in performing the role of the friction characteristics controlling mechanism, particularly the controlling mechanism having in addition slip controlling capabilities.
SANTOTRAC is a commercially available traction drive fluid and widely known to have an excellent power transmitting capability. Traction drive fluids to be used for automobile continuously variable transmissions are required to fulfill requirements in flowability at low temperatures and other performances, but such traction drive fluids have not been placed on the market yet.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a traction drive fluid which is superior not only in power transmitting capability but also has capabilities required as a fluid for a hydraulic controlling mechanism, i.e., flowability at low temperatures and capabilities required as a fluid for a wet type friction material controlling mechanism.
Therefore, the present invention seeks to provide a traction drive fluid particularly suitable for a continuously variable transmission of traction drive type which can be used for the power transmitting mechanism and also applicable to the hydraulic controlling mechanism and friction characteristics controlling mechanism of the transmission.
According to one embodiment of the invention, there is provided a traction drive fluid which comprises (A) one or more than two compounds selected from the group consisting of saturated polycyclic hydrocarbon compounds represented by the formulae
wherein R
1
and R
2
are each independently hydrogen or a methyl group, provided that the case where R
1
and R
2
are a methyl group at the same time is excluded, and R
3
and R
4
are each independently hydrogen or a methyl group;
wherein R
5
and R
6
are each independently hydrogen or a methyl group, provided that the case where R
5
and R
6
are a methyl group at the same time is excluded, and R
7
and R
8
are each independently hydrogen or a methyl group; and
wherein R
9
, R
10
and R
11
are each independently hydrogen or a methyl group.
According to another embodiment of the present invention, there is provided a traction drive fluid which comprises (A) the aforesaid polycyclic hydrocarbon compounds of formulae (1)-(3) and one or more than two compounds selected from the group consisting of polycyclic hydrocarbon compounds represented by the formula
wherein R
12
, R
13
and R
14
are each independently hydrogen or a methyl group.
According to further embodiment of the present invention, there is provided a traction drive fluid which comprises (A) the aforesaid polycyclic hydrocarbon compounds of formulae (1)-(3), (B) the aforesaid polycyclic hydrocarbon compounds of formula (4) and (C) at least one member selected from the group consisting of a mineral oil and a synthetic oil having an molecular weight of 150-800.
The traction drive fluid according to the present invention is preferably blended with (D) a viscosity index improver. Preferred viscosity index improvers are ethylene-&agr;-olefin copolymers having a number average molecular weight of 800-150,000 or hydrogenated products thereof.
Alternatively, the traction drive fluid of the present invention is preferably blended with (E) an ashless dispersant and (F) a phosphorus-containing additive.
Further alternatively, the traction drive fluid of the present invention is preferably blended with (G) a friction modifier having in its molecules at least one C
6
-C
30
alkyl or alkenyl group and no hydrocarbon groups of more than 31 carbon atoms.
Further alternatively, the traction drive fluid of the present invention is preferably blended with (H) a metal-containing detergent having a total base number of 20-450 mgKOH/g.
DETAILED DESCRIPTION OF THE INVENTION
The traction drive fluid of the present invention comprises (A) one or more than two compounds selected from the group consisting of saturated polycyclic hydrocarbon compounds represented by the formulae
wherein R
1
and R
2
are each independently hydrogen or a methyl group, provided that the case where R
1
and R
2
are a methyl group at the same time is excluded, and R
3
and R
4
are each independently hydrogen or a methyl group;
wherein R
5
and R
6
are each independently hydrogen or a methyl group, provided that the case where R
5
and R
6
are a methyl group at the same time is excluded, and R
7
and R
8
are each independently hydrogen or a methyl group; and
wherein R
9
, R
10
and R
11
are each independently hydrogen or a methyl group.
Alternatively, the inventive traction drive fluid may further contains (B) one or more than two compounds selected from the group consisting of polycyclic hydrocarbon compounds of the formula
wherein R
12
, R
13
and R
14
are each independently hydrogen or a methyl group.
The saturated polycyclic hydrocarbon compounds of formulae (1)-(3) can be produced by various methods. In general, the saturated polycyclic hydrocarbon compounds may be produced by synthesizing unsaturated polycyclic hydrocarbons by Diels-Alder reaction and subsequently hydrogenating the unsaturated polycyclic hydrocarbons, as specifically described below.
The Diels-Alder reaction of butadiene and/or isoprene with cyclopentadiene and/or methylcyclopentadiene proceeds to give norbornene compounds of formula (5), as shown in the following formula [I];
wherein R
1
and R
2
are each independently hydrogen or a methyl group, provided that the case where R
1
and R
2
are a methyl group at the same time is excluded, and R
3
is hydrogen or a methyl group.
Further Diels-Alder reaction of the norbornene compounds of formula (5) with butadiene or isoprene proceeds as shown in the following formula [II] thereby obtaining a 1:1 adduct of formula (6) of the norbornene compounds and butadiene and/or isoprene;
wherein R
1
and R
2
are each independently hydrogen or a methyl group, provided that the case where R
1
and R
2
are a methyl group at the same time is excluded, and R
3
and R
4
are each independently hydrogen or a methyl group.
When the norbornene compounds are subjected to Diels-Alder reaction with cyclopentadiene and/or methylcyclopentadiene, the reaction proceeds as shown in formula [III] the
Kiyota Takashi
Matsuno Mitsuo
Okawa Tetsuo
Shirahama Shinichi
Akin Gump Strauss Hauer & Feld L.L.P.
McAvoy Ellen M.
Nippon Mitsubishi Oil Corporation
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