DE2828918A1 - PROCESS FOR MANUFACTURING A PAPER-BASED FRICTION MATERIAL, IN PARTICULAR A CLUTCH COVERING FOR AUTOMATIC MOTOR VEHICLE TRANSMISSIONS - Google Patents

Description

TD IX patent attorneys:

IEDTKE - DÜHLING - IVlNNE Dipl .- 'ng. H. Tiedtke

Gr% Dipl.-Chem. G. Buehling

RUPE- Κ ELLMANN Dipl.-Ing. R. Kinne

2-828918 ^Di P '" ⁱⁿ 9- ^RGrLJ P ^e

* ■ ' ^w Dipl.-Ing. B. Pellmann

Bavariaring 4, Postfach 20 2403 8000 Munich 2

Tel .: 0 89-53 96 53

Telex: 5-24845 tipat

cable: Germaniapatent Munich

June 30, 1978

B 8985 / case v-012

AISIN CHEMICAL CO., Ltd. Kariya city / Japan

Process for the production of a paper-based friction material, in particular a clutch lining for automatic motor vehicle transmissions

The invention relates to a paper-based friction material, in particular to a clutch lining for automotive automatic transmissions, etc., and more particularly to a method of making such a friction material.

Clutch linings for automatic motor vehicle transmissions are generally made of a paper-based friction material in which, to improve the friction properties, for example the coefficient of friction and / or the abrasion resistance, contain certain components are.

809883/0909

Deutsche Bank (Munich) Kto 51/61070 Dresdner Bank (Munchunj Kto 'V119 614 Postscheck [Munihi-m Kto.

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2828S iti

In the known method of manufacturing a paper-based friction material (hereinafter referred to as
Referred to as "friction material"), known as the wet process, is used as a binder a resin in the liquid
State mixed in.

The friction materials are produced according to the known method as follows: Wood pulp, a lubricant, organic fibers and other components are mixed in a mixing device. By means of a
Paper machine, a paper is made from which by means of a paper stripping machine, z. Bj. By means of a £ r
Crank press, a product that has the required shape, is punched out. The punched product is soaked in a solution consisting of a binder, for example a phenolic resin, and a solvent. That
soaked product is dried and the dried product is preheated in a drying oven. The preheated product and a core plate are by means of a
And the contacted product is pressed and heated in a metal mold installed in a compression molding machine. This product is heated in a drying oven to produce the finished friction material. One task of the step in which the product is heated in the drying oven is to completely harden the binder and the adhesive, if they were not yet hardened.

There is much wood pulp, an organic compound, e.g. B. organic fibers, and a
Contain binders to achieve the desired friction properties. The desired frictional properties are achieved by charring a desired proportion of the wood pulp, etc.

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In the known method of manufacturing the friction material, however, the heating step is on The air carried out, whereby it comes to an oxidative decomposition of the material, so that the desired Frictional properties cannot be achieved. It is therefore common practice to complete the heating step before applying the Charring has reached the desired proportions of the wood pulp, etc. For these reasons it was on the market so far a friction material was available that did not yet have the desired frictional properties.

The above-described method is associated with difficulties that result in the friction material initially shows a low value of the coefficient of friction, so that it leads to the appearance of the "Looping in" is coming. Under the expression "appearance of the Grinding "is a property related to the power transmission to be understood through the friction material caused. This property is expressed in the fact that the coefficient of friction is low at the beginning, so that over a considerable number of hours the desired constant value for the coefficient of friction cannot be obtained, thereby causing a squeaking sound (crank sound).

It is assumed that the crank noise arises when the ratio of the static to the dynamic coefficient of friction of the friction material is greater than 1.30.

Accordingly, there is still a need to find a method by which a friction material can be produced that allows the desired, constant value of the coefficient of friction to be set right at the beginning achieve.

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The object of the invention is accordingly a method for producing a friction material, by means of which it is possible will achieve the desired, constant value of the coefficient of friction right from the start.

The invention relates to a wet process for producing a paper-based friction material, in particular of a material for use in a motor vehicle automatic transmission using a paper machine producing a paper which is characterized in that a semi-finished product of the friction material is produced paper-based before or after molding by means of heat and pressure in a vacuum-kept state Air, in an inert gas and / or in a heated liquid.

The preferred embodiments of the method according to the invention are explained in more detail below. at Investigations according to the invention with the aim of overcoming the difficulties encountered in the known method associated with the heating step, it has been found that the wood pulp and the others mentioned above Materials contained in the friction material are oxidized by the oxygen contained in the air and are also decomposed when the heat treatment is carried out. The friction material initially shows a low one Value of the coefficient of friction, therefore the desired constant value of the coefficient of friction and others desired Properties cannot be achieved.

The heat treatment is therefore according to the invention, such as mentioned above, in the air kept under reduced pressure, in the liquid and / or in the inert gas carried out. In the term "heat treatment" used according to the invention are a preheating, a heating and a post-heating step included.

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The preheating step is a process step in which an unremoved solvent with which the Friction material is soaked and which adheres to the friction material is removed from this, and in which the friction material obtained thereby is preheated so that the next step, the heating step, is carried out smoothly can be.

The heating step is the process step in which the desired proportions of the wood pulp and the other materials mentioned above without being oxidative Decomposition to be charred.

The post-heating step is the process step in which an uncured binder and an uncured adhesive are fully cured to bring the paper base of the friction material and a core plate into contact.

The term "liquid" used in the description includes various types of fluid, whose temperature can be increased, the fluid from the group of natural oils or by refining and Modifying a petroleum or a coal is obtained.

The group of natural oils includes non-drying, semi-drying and drying oils that are too belong to the vegetable oils.

Camellia oil, coconut oil, Olive oil, castor oil, etc. can be used.

Soybean oil, sesame oil, rapeseed oil, Cottonseed oil, etc. can be used.

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Safflower oil, linseed oil, tung oil, etc. can be used as the drying oil.

Animal oil is not preferred because it is generally in solid form, however whale oil can be used as a lubricant is used.

Other liquids can be selected from the group of oils or other liquids that can be obtained by refining and Modifying petroleum or coal preserves can be selected.

The named group of oils includes silicone oils, fluorinated oils, etc.

As silicone oil, the various modified oils of dimethyl and phenylmethyl types, etc. can be used.

A low molecular weight polymer can be used as the fluorinated oil of chlorotrxfluoroethylene etc. can be used.

Examples of the other liquids are plasticizers such as phosphoric acid esters, polyester, phthalates, esber based on Fefctsäurebasis etc. Other examples of a such liquid are polyethylene glycol, polybiphenyl chloride, etc.

Particularly preferred are the above-mentioned nondrying oils or a silicone oil.

In the term "inert gas" used in the description are noble gases such as helium, neon or argon and thermal stable gases such as carbon dioxide gas, nitrogen gas, etc. included.

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Gaseous nitrogen or gaseous carbon dioxide are particularly preferred in terms of cost and operation.

The expression "air held under reduced pressure" is to be understood as meaning air which is known according to known Process has been brought from atmospheric pressure to reduced pressure. .

The air kept under reduced pressure is therefore used because their oxygen content compared to that The oxygen content of the air under atmospheric pressure is reduced.

In the step where a semi-finished product of the friction material is kept under reduced pressure The air is heated, the better the heat treatment, the lower the oxygen concentration. Deciding to what extent the pressure is relieved depends on the quality required for the friction material or on the temperature and duration of the heat treatments. It is preferred to use atmospheric pressure to less than 293 mbar, in particular to less than 93 mbar, and to carry out the heat treatment.

The term "charring" used in the description is to be understood as meaning that the Wood pulp and the other materials mentioned above are decomposed by the heat and turned into a carbon-rich one Material, d. H. into an amorphous carbon, if the wood pulp and those mentioned above Materials are heated. The friction material can only have the desired coefficient of friction as above obtained when its charring is carried out in a suitable manner.

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It is difficult to precisely describe the preferable conditions in terms of the degree of char. It should a sufficient degree of charring can be determined, depending on the type of wood pulp used and the type of wood used, above-mentioned materials, in particular the wood pulp, the organic fibers or de.S binders ^ or on the heating temperature of the liquid.

The term "oxidation" used in the description is to be understood as meaning that the Combine wood pulp and the above-mentioned materials with the oxygen contained in the air. This appearance does not affect the properties of the friction material. According to the invention it has been found that it is larger Part of the wood pulp and the other materials mentioned above show signs of oxidation when the Heat treatment continuously at 130 ° C for about 30 minutes is carried out in the air.

The term "oxidative decomposition" used in the specification means the phenomenon which occurs when the above-mentioned heating step associated with the oxidation is carried out continuously for an extended period of time. This phenomenon has an influence on the properties of the friction material, which results from considerations and observations. According to the invention, it has been found that in the greater part of the ground wood and the above-mentioned materials, the phenomenon of oxidative decomposition occurs if the heat treatment is carried out continuously for about 2 hours at 200 ^° C. in air.

The method according to the invention is explained in more detail below.

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In the process according to the invention are in general The known process steps described below include: Mixing wood pulp with a Lubricants, organic fibers, and other ingredients in a blending device that uses paper making a paper machine, die-cutting by means of a paper stripping machine such as B. a crank press forming the required shape and soaking of the punched out product in a solution composed of a binder such as e.g. B. a phenolic resin and a solvent consists.

Then the heat treatment is carried out as mentioned above in the air kept under reduced pressure, in the liquid and / or in the inert gas until one a desired friction material is obtained in the desired proportions of the wood pulp and the other materials is charred. It is not possible to use all combinations of the aforementioned heat treatment steps and others Steps such as A drying process or a molding process carried out with the application of heat and pressure because there are many different types of these combinations. The following combinations are examples listed:

a) The above-mentioned soaked product is dried by means of a drying device, the dried one Product becomes in air, in air kept under reduced pressure or in an inert gas in the preheating step heated, then the dried product is molded using heat and pressure, whereupon the molded Product is heated in an inert gas or in air kept under reduced pressure, at the same time the heating and performing the post-heating step.

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b) The soaked product is sufficiently dried while the preheating step is carried out at the same time will. The dried product is heated in an inert gas or in air kept under reduced pressure, the reheating step being carried out at the same time. The heated product is made using heat and pressure molded.

c) The soaked product is sufficiently dried while the preheating step is carried out at the same time will. The dried product is heated in an inert gas or in air kept under reduced pressure. That heated product is molded using heat and pressure. The molded product is in the air, in under reduced Pressurized air or heated in an inert gas, the latter step being the post-heating step represents.

d) The soaked product is dried. The dried product is in the air, in under reduced Pressurized air or heated in an inert gas, this being a preheating step. That heated Product is molded using heat and pressure, and. then in a further preheating step heated by the air. The heated product is reheated in an inert gas or in air kept under reduced pressure, wherein the heating and the post-heating step are carried out at the same time.

e) The soaked product is dried. The dried product is in an inert gas or in under reduced Air is heated under pressure, this step being the preheating step. The heated product will molded using heat and pressure. The molded product is immersed in one of the liquids mentioned above

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heated to simultaneously the heating and the post-heating step perform. The liquid is removed from the heated product, if necessary.

f) The soaked product is sufficiently dried while the preheating step is carried out at the same time will. The dried product is heated in a liquid. The liquid will, if necessary, out removed from the heated product. The heated product is molded using heat and pressure.

g) The soaked product is sufficiently dried. The dried product is in a liquid heated. The liquid is removed from the heated product, if necessary. The heated product is under Using heat and pressure molded.

It is an important characteristic of these processes that there is no oxidative decomposition of the wood pulp and the above materials mentioned is caused when the product is preheated in air.

The above-mentioned air preheating step is preferably less than 1.5 hours carried out at 200 ° C for a long time.

A drying process step is also carried out, a low-boiling solvent such as. B. Remove methanol from the soaked product. That Solvent can be absorbed by and adhere to the die cut product while the die cut product is running is soaked in the solution containing the binder.

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The method step of drying v / ill generally with the soaked product at 30 ° C to 8O ⁰ C carried out for 20 minutes to 120 minutes in air.

The preheating step is generally carried out on the dried product for 0.5 h to 5 h at about 120 ° C. to 250 ° C.

The heating step is generally performed on the preheated product for 0.5 to 20 hours at about 120 ° C to 500 ° C.

The step of Nacherhitzens / ill generally with the molded product 0.5 conducted v h to 2 h at about 120 ⁰ C to 200 ° C.

The molding step is generally with the heated product by means of a molding machine such as e.g. B. a compression molding machine or by means of a roller such as z. B. by means of a pressure roller machine at 130 ° C to 200 ° C Carried out for 0.5 minutes to 5 minutes under a pressure of 49 bar to 118 bar.

A thermosetting resin such as. B, a phenolic resin or a polyimide resin is used.

The following describes the procedure by which the liquid is removed from the soaked product.

It is generally not necessary to use this process step because the liquid and the Most of the lubricants in the automatic vehicle transmission dissolve into one another and do not exert any influence, even if · the property of the friction material worsened.

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However, it happens that the environment deteriorates during the operation and that the liquid for Swelling of the friction material leads. In this way, the removal of the fluid from the friction material is required.

The first procedure for doing this is done by the heated product with the liquid in a solvent with a low boiling point such. B. methanol, ethanol, Xylene or toluene is immersed in order to thereby extract the liquid, and then by adding the extracted product to it dry in air or in an inert gas. The second method for doing this is done by putting the heated product with the liquid by means of a machine such as e.g. B. a roller or a compression molding machine to thereby to squeeze the liquid out of the heated product.

The combination of the first and second of the methods described above is also related to removal of the liquid effectively.

Under the term "semi-finished product of the paper-based friction material" used in the description are the above-mentioned soaked product, the dried one Understand product, preheated product, or molded product.

The invention is illustrated by the following examples explained in more detail.

Example 1_

Wood pulp in a fibrous state, a clay and diatomaceous earth were mixed in a mixer. Then became a paper is made from the mixture by means of a paper machine

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posed. Loops or rings were punched out of the paper using a crank press. The punched out product was in soaked in a solution of phenolic resin and methanol for 1 min. The soaked product was exposed to air at 70 ° C dried until the surface of the soaked product dried out.

The dried product was preheated in air at 160 ° C. for a further 50 minutes. The preheated product was brought into contact with a core plate by means of an adhesive. The contacted product was at 170 ° C Molded for 2 minutes in the metal mold of a compression molding machine under a pressure of 49 bar.

The molded product was immersed in preheated coconut oil at a temperature of 260 ° C. for 5 hours. That heated product was cooled in air to give the finished friction material.

Example 2

A molded product was prepared by the same procedure as described in Example 1, which was then immersed 7 h in preheated soybean oil having a temperature of 200 ⁰ C.

The heated product was immersed in soybean oil at room temperature and cooled therein, whereby the finished friction material was obtained.

Example 3

In the same manner as described in Example 1, a molded product was produced, which was then immersed in preheated ricinus oil at a temperature of 270 ° C. for 3 hours. The heated product was

809883/0909

pressed at room temperature for 1 hour by means of a compression molding machine under a pressure of 49 bar to the larger part remove the castor oil from the heated product.

Example 4

Following the same procedure as described in Example 1, a molded product was prepared which then immersed in the plasticizer tricresyl phosphate for 8 hours. The heated product was at room temperature cooled in air until it reached room temperature.

The cooled product was immersed in methanol at room temperature to remove the tricresyl phosphate dissolve and extract from the product. The product from which the tricresyl phosphate is dissolved and extracted was air dried at room temperature to give the finished friction material.

Example 5

By the same procedure as described in Example 1, a molded product was prepared, which then Was allowed to stand in the air at 170 ° C. for 1 hour.

After standing in the air, the product was immersed in preheated dimethyl silicone oil at one temperature for 5 hours immersed at 25O ° C. The heated product was cooled in air at room temperature, making the finished product Received friction material.

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Example 6

A molded product was produced by the same procedure as in Example 1, which was then used for 1 hour in gaseous nitrogen with a temperature of 170 ° C was left standing. After standing in nitrogen, the product was soaked in preheated methylphenyl silicone oil for 5 hours immersed at a temperature of 250 ° C.

The heated product was molded by means of a compression molding machine for 1 minute at 170 ° C. under a pressure of 49 bar pressed to the greater part of the methylphenylsilicon oil from the product and the finished friction material was obtained.

Example 7

A soaked product as mentioned above was obtained by the same method as described in Example 1 and then air-dried ^{at 60 ° C. for 1 hour.} The dried product was preheated in air at 160 ° C. for 1 hour.

The preheated product was brought into contact with a core plate by means of an adhesive. The product brought into contact was ^{molded for 2 minutes at 170 °} C. under a pressure of 98 bar.

The molded product was preheated to 270 ° C for 5 hours, heated with gaseous nitrogen. The heated product was cooled in air at room temperature, thereby obtaining the finished friction material.

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Example 8

A soaked product was obtained by the same procedure as described in Example 1 and then Air dried for 1 hour at 80 ° G.

The dried product was heated in gaseous nitrogen preheated to 280 ° C. for 3 hours. That heated Product was brought into contact with a core plate by means of an adhesive. The contacted product was at 170 ° C for 2 minutes using a compression molding machine a pressure of 98 bar.

The molded product was for 1 hour in preheated to 180 ° C, reheated with gaseous nitrogen. The post-heated product was cooled in the air, whereby the finished friction material received.

Example 9

A soaked product was obtained by the same method as described in Example 1 and then ^{air-dried at 70 °} C. for 30 minutes. The dried product was preheated in air at 160 ° C for 50 minutes.

The preheated product was brought into contact with a core plate by means of an adhesive. The product was brought into contact is formed at 170 ⁰ C for 2 minutes by means of a compression molding machine under a pressure of 49 bar.

The molded product was for 8 hours in preheated to 250 ° C, post-heated nitrogen gas to give the finished friction material.

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Example 10

A preheated product was prepared by the same procedure as described in Example 9 obtained, which was then heated for 1 hour with preheated to 300 ⁰ C, gaseous nitrogen. The heated product was brought into contact with a core plate by means of an adhesive. The contacted product was molded at 200 ° C. for 2 minutes by means of a compression molding machine under a pressure of 98 bar.

The molded product was post-heated for 1 hour in air preheated to 200 ° C and at room temperature on the Air cooled to give the finished friction material.

Example 11

A soaked product was obtained by the same procedure as described in Example 1 and then air-dried at 60 ° C for 1 hour. The dried product was preheated 1 hour at 160 ⁰ C in air.

The preheated product was brought into contact with a core plate by means of an adhesive. This in Contacted product was molded at 170 ° C. for 2 minutes by means of a compression molding machine under a pressure of 98 bar.

The molded product was heated for 2 hours at 270 ° C. in air kept under the reduced pressure of 133 mbar became. The heated product was gradually cooled in the air kept under reduced pressure, thereby the finished friction material was obtained.

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A soaked product was obtained by the same procedure as described in Example 1 and then Air dried for 1 hour at 80 ° C. The dried product was heated in air at 280 ° C. for 2 hours under the reduced pressure of 80 mbar was maintained.

The heated product was brought into contact with a core plate by means of an adhesive. That in contact Brought product was molded at 170 ° C for 2 minutes by means of a compression molding machine under a pressure of 98 bar.

The molded product was left in air at 180 ° C for 1 hour reheated, which was kept under the reduced pressure of 80 mbar. The post-heated product gradually became cooled to give the finished friction material.

Example 13

A soaked product was obtained by the same procedure as described in Example 1 and then Air dried for 30 minutes at 70 ° C. The dried product was preheated in air at 160 ° C for 50 minutes.

The preheated product was brought into contact with a core plate by means of an adhesive. The product was brought into contact is formed at 170 ⁰ C for 2 minutes by means of a compression molding machine under a pressure of 49 bar.

The molded product was heated at 300 ° C. for 3 hours in air kept under the reduced pressure of 27 mbar became. The heated product was gradually cooled in the air kept under reduced pressure, whereby received the finished friction material.

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A preheated product was obtained by the same procedure as described in Example 13 and then Heated for 5 hours at 250 ° C. in air which was kept under the reduced pressure of 200 mbar.

The heated product was brought into contact with a core plate by means of an adhesive. The product was brought into contact is formed at 200 ⁰ C for 2 minutes by means of a compression molding machine under a pressure of 49 bar.

The molded product was kept at 170 ° C. for 1 hour Air is reheated. The post-heated product was gradually cooled to give the finished friction material.

Comparative example 1

A molded product as mentioned above was obtained as described in Example 1 by the same procedure and then post-baked for 1 hour h in preheated to 180 ⁰ C air to obtain the final friction material,

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Table 1

Degree of wear

(mm)

Deceleration time (s)

number of
Operations
the clutch

2000

5000

100

200

1000 2000 3000 4000

5000

O
CO
CO
00

O
CO
O
CO

example

10
11
12th
13th
14th

Comparative example

0.042
0.039
0.036
0.039
0.030
C, O45
0.032
0.028
0.033
0.031
0.032
0.030
O, C39
0.033

0.06 2 0.058 0.054 0.058 0.048 0.057 0.053 0.046 0.052 0.049 0.049 0.045 0.058 0.045

1.05 1, 04 1, 00 0.98 1. 01 0.97 1, 03 1, 00 1, 04 1, 01 1, 03 1, 01 0.98 1.05

1, 03 1, 02 1, 02

0.97

1, 03 0.98 1, 03 1, 01 1, 05 1, 03 1, 02 1, 01 0.98 1, 04

1, 00 1, 02 1, 01 0.99 1, 02 1, 00 1, 05 1, 01 1, 05 1, 00 1, 03 1, 00 0.99 1, 04

, 01
, 01
, 00
, 01
, 02
, 01
, 03
, 00
, 02
0.99
, 04
, 02
, 00
, 02

, 01
, 00
, 01
, 00
, 01
0.99
, 02
, 02
, 01
, 00
, 04
, 01
0.99
, 02

, 01, 01, 00, 01, 01, 00, 03, 01, 00, 00, 04, 00, 00, 03

, 01 0.99, 00, 01, 02, 02, 03, 00, 03 0.99, 04, 01, 00, 03

, 00, 00, 02, 00, 00, 01, 02, 01, 02, 01, 03, 02, 01, 02

1, 01 1, 01 1, 00 1, 00 1, 01 1, 01 1, 03 1, 01 1, 03 1, 00 1, 03 T, 02 1, 00 1, 02

0.040 0.060

1.11 1.09 1.08 1.04 1.05 0.99 1.00 0.99 1.01

Tabel

Ratio of the static to the dynamic coefficient of friction

OT O CD OO CO CO

O CD O CO

number of
Operations of the
coupling 25th 100 200 500 1000 2000 3000 4000 5000 ho 1 example CQ
KJ ts) 1 1, 30 1, 28 1.25 1, 16 1.15 1.12 1, 10 1.13 1.11 I ^s ^ "
CO I. 2 1, 26 1.21 1, 20 1, 18 1.18 1.13 1, 09 1, 10 1, 09 CD 3 1, 18 1.19 1, 16 1.15 1.12 1, 10 1, 09 1, 10 1, 10 4th 1.27 1, 23 1, 24 1, 20 1.19 1.15 1, 16 1.13 1.13 5 1, 20 1.27 1, 18 1, 16 1, 16 1.14 1.13 1.14 1.15 CTl 1, 25 1.23 1.21 1, 17th 1, 16 1.13 1.14 1.12 1.14 7th 1, 20 1, 20 1, 18 1.17 1.15 1, 16 1.13 1.15 1.12 8th 1, 16 1.15 1.14 1.12 1.13 1.12 1, 10 1.12 1, 10 CB
co
VO 9 1.19 1.21 1.17 1, 18 1.15 1.13 1.11 1.14 1.13 10 1, 18 1, 16 1.15 1.13 1.14 1, 10 1.12 1.11 1, 09 11 1, 24 1.21 1, 20 1.19 1.17 1.15 1, 16 1, 18 1.15 12th 1.17 1.15 1.14 1.14 1.15 1.14 1.13 1.13 1, 10 13th 1, 18 1, 16 1.13 1.13 1.11 1, 10 1, 08 1, 10 1, 09 14th 1, 28 1, 25 1, 20 1.15 1, 16 1.15 1.12 1.13 1.13 Comparison
example 1 1.52 1, 59 1, 30 1.17 1.17 1, 12 1.11 1, 10 1.13

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A body of revolution that rotates at 3600 rpm in dynamic engagement and has a moment of inertia of

0.247 kg-m is made by a coupling with an inner diameter of 103 mm and an outer diameter of 127 mm under the action of a contact pressure of 3.07 kN braked and brought to a standstill.

The rotational energy (kinetic energy: 4A4.6 J) of the rotating body is taken up by the coupling. A clutch of this type is used for automotive automatic transmissions used. The oil used is kept at a temperature of around 120 ° C. The time for one cycle is 30 seconds, and a series of 5000 cycles is carried out. During the aforementioned test the braking time, the degree of wear, the static and the dynamic coefficient of friction are measured. In the Tables 1 and 2 each show the average value of five measurements.

The properties shown in Tables 1 and 2 are evaluated as follows:

After the lapse of 5000 cycles, a degree of wear of less than 0.06 mm is considered excellent, a degree of wear between 0.06 mm and 0.08 mm is considered good and a degree of wear greater than 0.08 mm is considered bad.

It is considered excellent if the deceleration time has a maximum value from the first to the five thousandth cycle of less than 1.10 s and a minimum value of more than 0.97 s, while the values 1.15 s and 0.95 s as to be viewed well. A maximum value for the deceleration time that is greater than 1.15 s is considered a bad value.

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For the ratio of the static to the dynamic coefficient of friction, a maximum value (from the first
up to the five thousandth cycle) of less than 1.2O is considered excellent, a maximum value between 1.20 and 1.3O is considered good, and a maximum value above 1.3O is considered bad.

809883/0909

Claims (32)

Claims 1. Method of making a friction material based on paper, in particular a clutch lining, characterized by a step in which a semi-finished product of the paper-based friction material in a liquid, in air maintained under reduced pressure and / or heated in an inert gas. 2. The method according to claim 1, characterized in that a natural oil is used as the liquid. 3. The method according to claim 2, characterized in that the natural oil used is a vegetable oil. 4. The method according to claim 3, characterized in that a non-drying oil is used as the vegetable oil. 5. The method according to claim 4, characterized in that the non-drying oil is Caiuellia oil, coconut oil, Olive oil or castor oil is used. 6. The method according to claim 3, characterized in that that a skin-drying oil is used as the vegetable oil. XI / so 809883/0909 ORIGINAL INSPECTED - 2 - B 8985 7. The method according to claim 6, characterized in that there is used as the semi-drying oil soybean oil, sesame oil, rapeseed oil or Cottonseed oil is used. 8. The method according to claim 3, characterized in that a drying oil is used as the vegetable oil. 9. The method according to claim 8, characterized in that the drying oil is safflower oil, linseed oil or a tung oil begins. 10. The method according to claim 2, characterized in that a whale oil is used as the liquid. 11. The method according to claim 2, characterized in that a fluid is used as the liquid, the temperature of which can be increased and which has been obtained by refining and modifying a petroleum or a coal. 12. The method according to claim 11, characterized in that a silicone oil is used as the fluid. 13. The method according to claim 12, characterized in that that the silicone oil that is used from various modified silicone oils of the dimethyl and phenylmethyl type selects. 14. The method according to claim 11, characterized in that a fluorinated oil is used as the fluid. 15. The method according to claim 14, characterized in that that a low molecular weight polymer of chlorotrifluoroethylene is used as the fluorinated oil. 809883/0909 - 3 - B 8985 2828316 16. The method according to claim 11, characterized in that that a plasticizer is used as the fluid. 17. The method according to claim 16, characterized in that that the fluid used is a plasticizer selected from phosphoric acid esters, polyesters and phthalates or esters based on fatty acids. 18. The method according to claim 11, characterized in that that a polyethylene glycol or a polybiphenyl chloride is used as the fluid. 19. The method according to claim 1, characterized in that a noble gas is used as the inert gas. 20. The method according to claim 19, characterized in that that helium, neon or argon are used as the noble gas. 21. The method according to claim 1, characterized in that the inert gas used is carbon dioxide or nitrogen. 22. The method according to claim 1, characterized in that that the semifinished product of the paper-based friction material is preheated in the form of a dried product, one Product, a heated product, a molded product or a post-heated product. 23. The method according to claim 1, characterized in that the semi-finished product is heated ^{to about 120 °} C. to 500 ^{° C.} 809883/0909 - 4 - B 8985 24. The method according to claim 23, characterized in that the semi-finished product to about 200 ° c heated to 35O ° C. 25. The method according to claim 24, characterized in that heating the semi-finished product to about 25O ° C to 300 ⁰ C. 26. The method according to claim 23, characterized in that the semi-finished product is about 0.5 h to Heated for 20 hours. 27. The method according to claim 26, characterized in that the semi-finished product for about 2 h to 8 h heated for a long time. 28. The method according to claim 27, characterized in that the semi-finished product for about 2 h to 5 h heated for a long time. 29. The method according to claim 1, characterized in that air is reduced below a to less than 293 mbar Pressure starts. 30. The method according to claim 29, characterized in that air is reduced to less than 93 mbar Pressure starts. 31. The method according to claim 1, characterized in that that the semi-finished product contains an organic compound. 32. The method according to claim 31, characterized in that that the semi-finished product is heated and then part of it is charred. 809883/0909