JPS633083A - Wet friction member - Google Patents

Abstract

PURPOSE:To obtain the titled pollution-free member keeping both grip performance and dynamic coefficient of friction equal to those of conventional one, free from development of debonding for a long time, useful for automobile clutch, etc., by incorporating a base material with specific alumina fiber. CONSTITUTION:The objective friction member consisting of (A) a base material prepared by incorporating a combination of (i) fiber, (ii) powdery filler and (iii) friction regulating agent with (iv) alumina fiber whose zeta-potential in water of pH5.5 is positive and (B) a binder mutually connecting the components (i), (ii) and (iii). Said component (iv) is pref. such that zeta-potential in water of pH5.5 is <=+20mV, content in the base material is 0.5-15wt%, diameter is 1-5mum, and length is 0.3-2mm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wet friction member used in vehicles such as automobiles. The present invention can be used, for example, in a wet friction clutch for power transmission that is used in a vehicle transmission while being immersed in oil.

[Prior art] Conventionally, this type of wet friction member consists of fibers, fillers, and 51Mg.
It is manufactured by mixing a conditioning agent in water and making paper into a base material, then impregnating it with a binder and curing it.

This filler and friction modifier are Iff! It is an important component that determines the quality of paper and must be integrally fixed to the fibers when paper is made. Conventionally, in order to fix these fillers and friction modifiers to fibers, for example, asbestos is used as a fixing material, and something that fixes by utilizing the entanglement with mH, or a sulfur band is mixed, and the filler and There are known methods in which the 1γ■ regulator is fixed between the fibers by agglomerating it, or in which a cationizing agent such as a cationic polymer is blended to lower the surface potential of the 111 fibers.

[Problems to be solved by the invention] In the above-mentioned various fixing methods, when asbestos is used, there are problems in terms of pollution, and when sulfuric acid band is used, red changes such as discoloration occur due to acidic papermaking. occurs. Further, when a cationizing agent is used, there is a problem that the fixing strength is low.

The present invention was made in view of the above circumstances, and uses a new fixing material without using asbestos. J
l! 'It provides parts.

[Means for solving the problems] The wet type f@ cavity member of the present invention includes U&fiber, powdery filler,
a base material consisting of a friction modifier, the fibers of the group H, the filler and the friction modifier g! A binder that binds XgJ water and such a wet friction member are characterized in that the base material contains alumina fibers having a positive ζ potential in water with a pH of 5.5.

As the fibers forming the base of the wet friction member of the present invention, both organic fibers and inorganic fibers can be used, as in the past. Examples of organic fibers include link valves, wood valves, synthetic valves, polyester fibers, acrylic fibers, fat [1/j group borif 7mid 4Bm, polyvinyl alcohol modified fibers, polyvinyl chloride 111, polypropylene fibers, and aromatic polyamide fibers. , carbon $31 N,
It is possible to use one species or a mixture of two or more species. In addition, titanium potassium fiber, glass fiber, kaolin XHN, silica fiber, bauxite mi, kyanite IIN, boron 4M cloth, magnesia fiber, rock wool fiber, metal! One or more kinds of miscellaneous materials can be used. It is preferable that the organic fiber is 10 to 70% by weight in the friction member, and has no IR.
It is preferable to use the fiber in an amount of 2 to 50%.

As the filler, either an organic filler or an M machine filler can be used as in the conventional case. For example, silica, talc, magnesium oxide, kaolin, barium sulfate, quicklime, calcium phosphate, calcium carbonate, diatomaceous earth, etc. can be used.

Note that it is desirable that this filler be contained in the paper in an amount of 5 to 550% by weight.

Friction modifiers are used to improve or stabilize the coefficient of friction, and include, for example, metal powders such as aluminum powder, copper powder, and iron powder, rubber powder, cashew dust, and graphite powder. This friction modifier can be blended in an amount of 5 to 30% by weight as in the conventional case.

The greatest feature of the present invention is that the 4M material contains alumina uxm whose ζ potential is a positive potential. Note that this ζ potential is measured under conditions in water of pH 5.5, and it is desirable to have a potential of +20 mV or more.

Conventionally, for example, in Japanese Patent Application Laid-Open No. 57-85876, I? ! A rubbing member is disclosed. However, for this type of PJ material, alumina is 1! The fibers are used as heat-resistant U&fibers, and are not used for the purpose of improving the yield of fillers and friction modifiers during paper making.

The ζ potential of conventionally used fibers and fillers in water at pH 5.5 is generally negative.

For example, glass fiber has a voltage of -59 mV, and alumina silica! ! Navy blue is -4 mV.

Therefore, in the present invention, by using alumina fibers with a positive potential, fibers, fillers, and 11! The friction modifier and alumina fibers are electrically bonded and fixed together. In this sense, if the ζ potential of the alumina fiber is less than +20 mV, the fixing effect will be reduced, which is not preferable. In addition, asbestos that is conventionally used is +
It has a ζ potential of 27 mV, which is presumed to contribute to the fixing effect. However, asbestos has problems in terms of pollution, and as a result of intensive research, the present inventors found that
The present invention was completed by discovering that alumina fibers with a positive ζ potential give good results in fixing.

Alumina fiber is straight 1! 1~5 μm 1 length 0.3 layer 2 Peng
Preferably. Preferably, this alumina at, G[ is contained in a small amount of 0.5 to 15% by weight in the friction member. If it exceeds 15,000%, the aggressiveness towards the mating material becomes noticeable, which is not desirable.

In addition, the friction member of the present invention contains 0.1 to 5% by weight of a paper strength agent such as acrylic resin, polyamide resin, polyacrylamide resin, or melamine resin in order to increase the strength during paper making.
It is also preferable to use

The binder is used to integrally bind the base material made of paper-made fibers, fillers, S original water content, etc., and as in the past, phenol resin, epoxy riAln, melamine resin, urea resin, polyimide resin, etc. Generally, 20 to 40% by weight of R can be used based on the base material from which the paper is made. In some cases, a non-isolated binder such as colloidal silica may also be used.

To manufacture the ME member of the present invention, first, IJA miscellaneous material is put into water and beaten by repeating compression and recovery.

Next, the alumina fibers are added, followed by the filler material and friction modifier. At this time, U&fiber, filler and I#J
Friction modifiers generally have a negative ζ potential, and alumina fibers have a positive potential, so the friction modifiers are attracted to and fixed on the alumina fibers. The friction member of the present invention can be manufactured by making paper, drying it, impregnating it with a liquid binder, and then curing the binder.

[Actions and Effects of the Invention] The present invention! 1! In the m1 layer, alumina sum having a positive ζ potential is used in the fiber. When in a suspended state before papermaking, AI#1 with a negative ζ potential, the filler, and the friction modifier are attracted to the alumina m fibers. This fixes the filler and friction modifier, and improves the yield of the filler and we modifier during paper making. Therefore, there is no need to use asbestos as in the past, so the yield of fillers, etc. can be maintained at the same level as in the past, and J! A J gap member can be manufactured. Furthermore, since there is no need to use the 11A11 band, changes over time such as discoloration can be reduced.

[Example〕 This will be explained in detail below using examples.

(Example 1) Link pulp 50 weight parts and aramid fiber 10 type assembled parts 6
000 Judenbu 0 Put it in water and use the beater to or+s L
tc. Next Near) LtmitmNS a f f i l
I (eta, manufactured by IC1, 0.5 parts by weight of ζ electricity (Q +48 m V > in water with pH 5.5) was added and mixed uniformly, then 15 parts by weight of cashew dust, 5 parts by weight of potassium titanate , and 25 parts by weight of diatomaceous earth,
Furthermore, two small peaks of paper strength agent made of acrylic resin were added and the beater was operated until they were uniformly mixed. This suspension is then made into paper using a circular mesh paper machine and dried to a basis weight of 200 (]/
A Km member base material having a thickness of 0.6 mm and a thickness of 0.6 mm was obtained. This base material was impregnated with 30% resol type phenolic resin and heated at 180° C. for 20 minutes to obtain the friction member of Example 1.

The yield rate, dynamic friction coefficient, and peeling resistance of the obtained friction member were measured and shown in the table and figure.

The yield rate is determined by the ratio of the remaining φ after heating at 600°C for 1 hour in a Matsufuru furnace to the proportion of solids in the suspension before papermaking. . Also dynamic S
The friction coefficient was determined by SAE #2 test machine at 3 rotations in ATF oil.
The peeling resistance test was conducted under the following conditions: 600 rpm, a load of 7゜2 kg/Crn'', an inertia of ?2.5 kg・cm・sec', and a temperature of 120℃.The peeling resistance test was conducted under the following conditions: the inertia in the dynamic friction coefficient was set to 3.5 kg-cm- The measurement of the dynamic coefficient of friction was carried out in the same manner as in the measurement except that the coefficient of friction was set to 5ec2, and the rotational speed at the time when spot peeling occurred was fixed at 3111.

(Example 2) The friction member of Example 2 was prepared in the same manner as in Example 1 except that 2 parts by weight of alumina fiber was used, beaten and paper-made, and impregnated with a binder and solidified to obtain a friction member of Example 2 with an IQ of 1ζ. The yield rate and dynamic a! of the obtained friction member were the same as in Example 1. The friction coefficient and peel resistance test were measured and the results are shown in the table and figure.

(Example 3) The FJv1 member of Example 3 was obtained by beating and paper-making in the same manner as in Example 1, except that the alumina fiber was used in an amount of 10 parts by weight, and then impregnated with a binder and solidified.

Then C1! As in Example 1, the yield rate and dynamic I! The J friction coefficient and peel resistance test were measured and the results are shown in the table and figure.

(Comparative Example 1) Beating and papermaking were carried out in the same manner as in Example 1, except that no alumina fiber was used and a cationic fixing agent (Arafix 1001 manufactured by Arakawa Chemical Industry Co., Ltd.) was used in two parts. A friction member of Comparative Example 1 was obtained by impregnating and solidifying a binder. Then, the yield rate, dynamic friction coefficient, and peeling resistance test were measured for the obtained friction member in the same manner as in Example 1, and the results are shown in the table and the figure.

(Comparative Example 2) Example 1 except that the alumina fiber was 0.2 parts by weight
A friction member of Comparative Example 2 was obtained by beating, paper-making, impregnating and solidifying a binder with the same formulation as above.

Then, the yield rate, dynamic friction coefficient, and peeling resistance test were measured for the obtained friction member in the same manner as in Example 151111, and the results are shown in the table and the figure.

(Comparative Example 3) The alumina fibers were used in the same manner as in Example 1 except that the alumina fiber was used at 20 weights and 1 part, the beating and paper making were carried out in the same manner, and the binder was impregnated and assimilated. I got one house part.

Then, the yield rate, dynamic friction coefficient, and peeling resistance test were measured for the obtained friction member in the same manner as in Example 1, and the results are shown in the table and the figure.

(Evaluation) It is clear from the table that the friction members of the examples of the present invention have substantially the same yield rate as the comparative examples. In other words, it has the same fixing performance as the conventional one even without using asbestos or sulfuric acid band.

Also, it is clear from the figure that the dynamic friction coefficients of the friction member of the example and the friction member of the comparative example are almost the same, and iN
JM occurs at a lower rotational speed in the friction member of the comparative example. In addition, Comparative Example 2 had a low yield rate and poor peeling resistance because of the small amount of alumina fiber, and Comparative Example 3
In this case, peeling resistance could not be measured because the mating material was worn.

In other words, a! of this example! The rubbing member improves fixing performance and dynamic I! j! In addition to maintaining the same therapeutic coefficient as before, there is no pollution problem, and the occurrence of IL peeling can be prevented for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the measurement results of the dynamic coefficient of friction, and FIG. 2 is a graph showing the results of the peeling resistance test. Patent applicant Aisin Kako Co., Ltd. agent
Patent Attorney Hirodo Okawa Patent Attorney Akio Maruyama

Claims (4)

[Claims] (1) A wet friction member consisting of a base material made of fibers, a powdery filler, and a friction modifier, and a binder that binds the fibers, the filler, and the friction modifier of the base material. A wet friction member characterized in that the base material contains alumina fibers having a positive ζ potential in water of pH 5.5. (2) Alumina fiber is +20 in water with pH 5.5
The wet friction member according to claim 1, which has a ζ potential of mV or more. (3) The wet friction member according to claim 1, wherein the base material contains 0.5 to 15% by weight of alumina fibers. (4) Alumina fiber has a diameter of 1 to 5 μm and a length of 0.3 to 2
The wet friction member according to claim 1, which is mm.