Coating processes – With post-treatment of coating or coating material – Heating or drying
Reexamination Certificate
2001-11-13
2004-07-06
Cameron, Erma (Department: 1762)
Coating processes
With post-treatment of coating or coating material
Heating or drying
C427S387000, C427S411000
Reexamination Certificate
active
06759093
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for manufacturing a wet type friction material, particularly used in a wet type clutch.
2. Related Background Art
In automatic transmissions of vehicles, for example, motor vehicles, a multi-plate clutch or a lock-up clutch has been used, and wet type friction materials have been used in frictional engagement elements for such a clutch.
FIG. 3
is a front view of a friction plate used in a multi-plate clutch. The friction plate
1
is constituted by adhering wet type friction material(s)
3
to one side or both sides of a core plate
2
.
The wet type friction material
3
is generally produced by making paper comprised of fiber base material such as natural pulp fibers, organic synthetic fibers or inorganic fibers and filler/friction adjusting agent such as diatom earth or cashew resin in a wetting manner and then by immersing resin binding agent comprised of thermosetting resin into it and by thermosetting it.
There are various thermosetting resin materials, and such resin materials have been developed more and more, but they have inherent merit(s) and demerit(s).
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a method for manufacturing a wet type friction material, in which demerit of one binding agent is compensated by the other binding agent thereby to provide excellent effect. More specifically, an object of the present invention is to suppress weakness or tenderness which is demerit of silicon resin by using phenol resin while maintaining elasticity or flexibility which is merit of the silicon resin and high coefficient of friction accordingly, and to provide a method for manufacturing a wet type friction material in which tenderness is suppressed.
To achieve the above object, the present invention provides a wet type friction material having fiber base material, filler and binding agent and comprising a first layer including first binding agent and a second layer including second binding agent.
Further, the present invention provides a method for manufacturing a friction plate obtained by fixing a wet type friction material to a core plate, in which the wet type friction material includes a first layer immersed by phenol resin and a second layer immersed by phenol resin and silicon resin and the first layer side is secured to the core plate and the second layer side is used as a frictional engagement surface.
Further, the present invention provides a method for manufacturing a wet type friction material obtained by immersing binding agent into a paper body comprised of fiber base material and filler, comprising a first immersing step for immersing first binding agent into the paper body, a second immersing step for immersing second binding agent into the paper body after the first immersing step, and heating and curing step for heating and curing the paper into which the first and second binding agents are immersed.
In order to manufacture the wet type friction material according to the present invention, a paper body is firstly formed. The paper body is formed by making paper, in normal manner, from slurry liquid obtained by dispersing fiber base material and filler/friction adjusting agent into water at a predetermined ratio and drying the paper. The paper body is not limited to the above-mentioned one.
As the fiber base material, for example, one or more of inorganic fibers such as glass fiber, rock wool, potassium titanate fiber, ceramic fiber, silica fiber, silica/alumina fiber, calion fiber, bauxite fiber, kayanoid fiber, boron fiber, magnesia fiber, metallic fiber and the like and organic fibers such as link pulp, wood pulp, synthetic pulp, polyester fiber, polyamide fiber, polyimide fiber, polyvinyl denaturation alcohol, polyvinyl chloride fiber, polypropylene fiber, polybenzo imidal fiber, acrylic fiber, carbon fiber, phenol fiber nylon fiber, cellulose fiber, aramid fiber and the like may be used.
As the filler/friction adjusting agent, for example, one or more of barium sulfate, calcium carbonate, magnesium carbonate, silicon carbide, boron carbide, titanium carbide, silicon nitride, boron nitride, alumina, silica, zirconia, cashew dust, rubber dust, diatom earth, talc, calion, magnesium oxide, molybdenum disulfide, nitrile rubber, acrylonitrile butadiene rubber, styrene butadiene rubber, silicon rubber, fluororubber and the like may be used.
Phenol resin is used as the first binding agent. The phenol resin is not particularly limited, but, for example, pure phenol resin or epoxy denaturation phenol resin may be used.
Silicon resin is used as the second binding agent. Cured material of hydrolysis liquid of silane coupling agent is used as the silicon resin. The hydrolysis liquid of silane coupling agent can be obtained by pouring silane coupling agent (as main material) and water (and solvent, if necessary) by mixing and agitating these substances for a predetermined time period (for example, about 3 to 5 hours) under a room temperature or a relatively low temperature (lower than boiling point of the solvent (low class alcohol); for example, about 40 to 50° C.).
The silane coupling agents having the following chemical formulae (1) and (2) were used.
(R
1
)(R
2
)
n
Si(OR
3
)
3−n
(1 )
(In the above formula, R
1
represents alkyl-amino group having first class amine at its end, R
2
and R
3
represent alkyl group having independent carbon number of 1 to 3, respectively, and n is the integral number of 0 or 1)
(R
4
)
m
Si(OR
5
)
4−n
(2)
(In this formula, R
4
and R
5
represent alkyl group having independent carbon number of 1 to 3, respectively, and m is the integral number of 1 or 2)
In the mixture of the silane coupling agents, silane coupling agent having three or more hydrolysis groups is used as at least one of the silane coupling agents represented by the formula (1) or (2). In the hydrolysis liquid of silane coupling agent, it is preferable that blending is effected so that ratio of molar number of the silane coupling agent shown by the formula (2) with respect to molar number of the silane coupling agent shown by the formula (1) becomes 0.1 to 10. Further, in the hydrolysis liquid of silane coupling agent, it is preferable that an adding amount of water is greater than an amount by which half or more of hydrolysis groups in the silane coupling agent an be subjected hydrolysis and smaller than twice of an amount by which all of hydrolysis groups in the silane coupling agent can be subjected to hydrolysis.
More specifically, in the silane coupling agent shown by the above formula (1), as amino silane having three alkoxy group within one molecule, 3-amino propyl trimethoxy silane, 3-amino propyl triethoxy silane, N2-(amino ethyl) 3-amino propyl trimethoxy silane and the like can be listed up, and one of them or mixture thereof can be used. Further, as amino silane having two alkoxy group within one molecule, 3-amino propyl methyl dimethoxy silane, 3-amino propyl methyl diethoxy silane, N-2-(amino ethyl) 3-amino propyl methyl dimethoxy silane, N-2-(amino ethyl) 3-amino propyl methyl diethoxy silane and the like can be listed up, and one of them or mixture thereof can be used.
On the other hand, in the silane coupling agent shown by the above formula (2), 3-functional methyl trimethoxy silane, 3-functional methyl triethoxy silane, 2-functional dimethyl dimethoxy silane, 2-functional dimethyl diethoxy silane can be listed up, and monomer thereof or low compression substance (for example, about 2 to 5 parts) of one or more mixture thereof can be used. Further, silane coupling agent having three or more hydrolysis groups is used as at least one of the silane coupling agents shown by the formulae (1) and (2). It is preferable that the silane coupling agents are compounded so that a ratio of molar number of the silane coupling agent shown by the formula (2) with respect to molar number of the silane coupling agent shown by the formula (1) becomes 0.1 to 10. If the ratio between the molar numb
Matsuda Shunya
Takahara Hiroshi
Cameron Erma
Miles & Stockbridge P.C.
NSK-Warner K.K.
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