JPS59170541A - Clutch facing with improved rust proofing property - Google Patents

Abstract

PURPOSE:To improve the judder resistance and at the same time prevent the clutch facing from rusting by a method wherein the contents of Cl<-> ion, SO4<2-> ion, and sodium nitrite ion and the hydrogen ion concentration, and the pH and the rate of moisture absorption of wear-resistant powder are set to specified values respectively. CONSTITUTION:The content of binding agent resin is set to 10-20wt% of clutch facing and at the same time the contents of Cl<-> ion and SO4<2-> ion in the clutch facing are respectively set to 0.2mg or less per gram of clutch facing. The content of sodium nitrite ion is set to 1.0-7.0mg per gram of clutch facing and the hydrogen ion concentration and rate of moisture absorption of wear-resistant powder in the clutch facing are set 10wt% or less and a pH to 6-9 respectively. In this case, the clutch facing contains fibrous substance and the like excluding said resin. Further, phenol-formaldehyde resin or the like is employed as said resin. Due to the materials as mentioned above, the judder resistance can be improved and at the same time the rusting of the clutch facing can be prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch facing with improved rust resistance.

Clutch facing, asbestos, suf.

It is molded using a formaldehyde condensation resin binder with a fibrous material such as polyamide fiber, phenol type, melamine type, etc.

The clutch facings obtained in this way are important parts of automobiles and have excellent wear resistance during driving.

In addition to having excellent shudder resistance, the clutch facing and mating material (
flywheel or pressure plate), there is no rust between the clutch facing and the mating material even in such conditions, and the latch operation is smooth even when starting to use after long-term storage. Must be possible.

However, actual clutch facings are molded products made of composite materials as mentioned above, and shudder resistance is important, so reducing the content of binder resin will cause rust to occur between the facing and the clutch facing. It may rust to the extent that it is difficult to operate.

Of course, to prevent these adverse effects, sodium nitrite I is added to the molded product.
Jum-based rust preventive treatment is also used,
Depending on the conditions of use, satisfactory results may not always be obtained.

An object of the present invention is to provide a clutch facing that has excellent shudder resistance and is rust-free.

The present inventors have determined that the cause of rusting on clutch facings is due to the content of Cl-S04 in the clutch facings.
As a result of detailed research in relation to the content of sodium nitrite, the pH of the anti-wear powder, and the moisture absorption rate, it was possible to obtain a clutch facing with excellent shudder resistance and improved rust resistance.

In the present invention, a binder resin is contained in the clutch facing in a weight ratio of 10 to 20%, and the clutch facing contains carbon dioxide.
The content of both F and S O"4- is 0.2 to less than 1 ψ of clutch facing, and sodium nitrite is contained 1.0 to 7.0 μ per 1 g of clutch facing. Adjust the pH of wear-resistant powder to 6~
9, and relates to a clutch facing with improved rust prevention properties and a moisture absorption rate of 10% by weight or less.

The clutch facing of the present invention contains fibrous substances, metal wires, wear-resistant powder, etc. in addition to the above binder resin, and the fibrous substances include asbestos, glass fibers, potassium titanate fibers, polyamide resin fibers, etc. are used, and the metal wire is made of steel,
Brass, zinc, etc. are used, and phenol, alkylphenol, cashew shell oil-based resin cured products, etc. are used as the wear-resistant powder.

As binder resins, phenol/formaldehyde sti, alkylphenol/formaldehyde resins,
Melamine formaldehyde resin.

Formaldehyde condensation resins such as benzoguanamine formaldehyde resin, urea formaldehyde resin, alcohol-modified amino resin, furan formaldehyde resin, and ketone formaldehyde resin are available, and mixtures thereof or cocondensation resins thereof can also be used. Further, rubbers such as styrene, butadiene, rubber, and acrylonitrile rubber can also be used in combination, but formaldehyde-based condensation resins are preferred from the viewpoint of heat resistance and wear resistance properties of the clutch facing. This condensing agent resin has a weight ratio of 10 to 20 for the clutch facing,
If it exceeds 20% by weight, the shudder resistance will be poor and
If it is less than 96, the function as a clutch facing will be poor.

The content of CI- and SO'24- in the clutch facing is set to be less than 0.2m9 per 1ψ of the clutch facing, and if it exceeds 0.2cm, rust prevention becomes difficult.

This content can be achieved by using a raw material that satisfies this condition, or by washing the clutch facing with ion-exchanged water during or after the manufacturing process of the clutch facing.

Is the content of sodium nitrite in clutch facing 1? The area is 1.0 to 7.0 m9, preferably 2.0 to 5.0 m9.

The content of IJium (nitrite) is less than 1.04.

It is difficult to prevent rusting, and rust will not occur due to the hygroscopicity of sodium nitrite itself when the temperature exceeds 7.0■, but depending on the environment, the adhesion force between the clutch facing and the mating material may increase. tends to occur.

The content of CJ- and SO'4- and the content of sodium nitrite in the clutch facing were determined by adding ion-exchanged water to 1ψ of the clutch facing and heating and boiling the mixture.

It can be confirmed by measurement using ion chromatography after extraction.

The clutch facing of the present invention requires the pH of the wear-resistant powder in the clutch facing to be in the range of 6 to 9. If acidic wear-resistant powder with a pH of less than 6 is used, the clutch facing must be Treatment with an alkaline substance during or after the manufacturing process 9 For example, by adding an alkaline substance such as sodium carbonate or magnesia, or using an aqueous solution of these alkaline substances, the pH is adjusted to a range of 6 to 9. Preferably, after producing the clutch facing, the pH is adjusted to a range of 6 to 9 by adding an alkaline substance or using an aqueous solution of the alkaline substance. In addition to the above, a rust prevention treatment liquid may be used to adjust the pH to a range of 6 to 96-.

Wear-resistant powder has a pH of 6 to 9 in clutch facing.
It is fine as long as it is within the range of , and is not necessarily wear resistant.

It is not necessary to use the flour at a pH of 6-9 beforehand.

The fact that the wear-resistant powder in the clutch facing has a pH of 6 to 9 means that the wear-resistant powder in the clutch facing can be separated and pH
Confirmed by measuring H. When a sodium nitrite-based rust preventive is used at a pH of less than 6, nitrous acid (IJ) undergoes a chemical change, resulting in depletion and generation of some nitrate ions (NO3). In such a system, it can be determined whether the pH is within the range of 6 to 9 by examining the amount of sodium nitrite depleted or the amount of nitrate ions produced.

If the pH is within the range of 6 to 9, the production of nitrate ions is extremely small. The amount of nitrate ions produced can be measured by ion chromatography or the like, and the amount of sodium nitrite depleted can be confirmed by measuring the content of nitrite ions by ion chromatography.

In the present invention, the wear-resistant powder in the clutch facing is p
The pH range is from 6 to 9, and if the pH is less than 6, more nitrate ions are produced and rust is likely to occur. Furthermore, if the pH exceeds 9, depending on the chemical reaction between the alkaline substance and asbestos and the properties of the alkaline substance itself, there is a tendency for adhesive force to occur between the clutch facing and the mating material even if no red rust is formed.

Already known methods can be used to prevent rust on the clutch facing obtained in the present invention. For example, a method can be used in which the clutch facing is immersed in a sodium nitrite-based rust preventive solution and then dried.

The moisture absorption rate of the clutch facing is 10% by weight or less, preferably 5% by weight or less. Moisture absorption rate is 10% by weight
If the value exceeds 0.05%, an adhesion force will occur between the clutch facing and the mating material. The moisture absorption rate described here is when the clutch facing is at a temperature of 30°C.

This is the moisture absorption rate of the clutch facing when it is left standing for 24 hours in an environment with a relative humidity of 95 degrees.

The present invention will be explained below with reference to Examples.

Example 1 Asbestos yarn [80% by weight of asbestos, 10% by weight of cashew shell oil-based resin cured product (phenol-based resin cured product) (pH 9.0 of extracted water), 10% by weight of cloth and metal wire] with melamine/formaldehyde resin [Formaldehyde/melamine = 3/1 (mole ratio) 20 weight ratio solution pH 10,
5] was impregnated with a mixture of water and methanol solution at a solid content of 20% by weight.9 Then, it was dried, and this was heated (150°C).
The mold was cured for 30 minutes under pressure (50hf/cm9) L.

Thereafter, the surface was polished to obtain a clutch facing N.

Clutch facing (C1- and SO per 11 of Al
The contents of ; and - were 0.09 and 0.19, respectively. Next, this clutch facing A) nitrous acid)
After being immersed in a rust prevention treatment solution containing 2% by weight of IJum (manufactured by Mitsubishi Kasei) for 5 minutes, it was dried at 80'C for 1 hour to obtain a clutch facing (Bl).

The content of sodium nitrite per y of this clutch facing (B) was 3.5 ■. The moisture absorption rate was 5% by weight. Furthermore, the rusting force measured by the clutch facing 9- (Bl rusting test method is 0 to 0)
, OI V4f/lyn'. The shudder resistance tested in an actual vehicle was good. The clutch facing collar wear-resistant powder 1f was taken out, 10 ml of water was added thereto, heated and extracted, and then the pH was measured at room temperature and found to be 8.5.

Example 2 Asbestos yarn [asbestos 70% by weight, cafni shell oil-based resin cured product 20% by weight (extracted water pH 4.0).

10% by weight of fabric and metal wire] with glycine at a pH of 0.4
R, added melamine/formaldehyde resin [formaldehyde/melamine-3/1 (molar ratio).

Glycine 0.4% PHR (0.4% based on resin solid content)
pH 8.6 of the 20-weight adsorption resin solution to which 4% by weight) was added.
] was impregnated with a solid content of 20% by weight, followed by drying, followed by the same steps as in Example 1 to obtain a clutch facing fcl.

C/- per 1z of clutch facing FC+ and 80
The content of 2- is 0.09■ and 0.26Tng, respectively.
Met. Next, this clutch facing (C) was treated with 10-nolamine (Wako reagent grade 1) 2% by weight (pH 10.6).
) for 90 minutes to perform neutralization treatment. Thereafter, the clutch facing C1 was soaked in ion-exchanged water for 90 minutes and then washed with water. 80℃ after water washing
After drying for 1 hour, the clutch facing (D) was obtained. As a result, CZ per 1y of clutch facing (D)
The contents of - and SO knee are 0.09■ and 0.2, respectively.
It was 6 mg, but it became 0.07 mg, 0.20Q;'. Next, this clutch facing (Dl?'J
A clutch facing (E) was obtained by applying rust prevention treatment in the same manner as in Example 1.
The content of sodium nitrite per y was 3.2 . The moisture absorption rate was 6% by weight. Clutch facing (El rusting force is 0 to 0. OI Kgf/cm'
Met. The shudder resistance tested on an actual vehicle was extremely good. In addition, the pH of the wear-resistant powder was adjusted in the same manner as in Example 1.
When measured, the pH was 6.3.

Comparative Example 1 The clutch facing obtained in Example 1 (clutch facing F was obtained by immersing the body in a rust prevention treatment solution containing 5% by weight of sodium nitrite for 5 minutes and then drying it at 80° C. for 1 hour). 1y- of this clutch facing (F)
The content of IJium is 8. It was OTv. The moisture absorption rate was 111% by weight.

Although no rust occurred on this clutch facing (F'l), it produced a sticking force of 0.3 to 0.8 Kpf/crn'.The shudder resistance conducted on an actual vehicle was poor due to the occurrence of shudder. Further, when the pH of the wear-resistant powder was measured in the same manner as in Example 1, it was found to be 8.5.

Comparative Example 2 The clutch facing tc) obtained in Example 2 was washed with ion-exchanged water for 90 minutes. After washing with water, drying was carried out at 80°C for 1 hour to obtain clutch facings (Gl). Next, this clutch facing 0 was subjected to anti-corrosion treatment in the same manner as in Example 1 to obtain a clutch facing round.The content of sodium nitrite per unit 11 of this clutch facing round was 3.31n9. The moisture absorption rate was 7% by weight.The rusting force of the clutch facing (2) was 0.15 to 0.45 Kyf/crn', which was poor.

The shudder resistance tested in an actual vehicle was good. In addition, the pH of the wear-resistant powder was measured using the same method as in Example 1.
H was 5.2.

Comparative Example 3 The clutch facing (3) obtained in Example 1 was immersed in a rust prevention treatment solution containing 1.0% by weight of 13 um for 1 minute, and then dried at 80°C for 1 hour to prepare a clutch facing. Po) was obtained. This clutch facing (I
The sodium nitrite content per ψ of ) was 0.8η. Moisture absorption rate 1d: 4% by weight.

The rusting force of the clutch facing (I) is 0.02 to 0.
It was found to be defective at 05Kof/cm'. The shudder resistance tested in an actual vehicle was good. Further, when the pH of the wear-resistant powder was measured in the same manner as in Example 1, the pH was 8.6.

<Rust test method> The clutch facing was cut into 154m square pieces with the original thickness, and was brought into close contact with cast iron FC-25 of the same size. 2. Apply a load of "OKgf/m". This is placed in a constant temperature and humidity chamber (50°C, 90% RH) and a dryer (60°C
) for 12 hours each cycle for a total of 15 days.

After that, remove the load and connect the clutch facing and cast iron FC-
The rust adhesion force was determined by measuring the adhesion force in the shear direction between 25 and 25 using a spring scale.

<Method for Measuring Moisture Absorption> The entire clutch facing was dried at 100° C. for 3 hours to determine its dry weight, and then left to stand in a constant temperature and humidity chamber maintained at a temperature of 30° C. and a humidity of 95° C. After 24 hours, the dampened clutch facing was taken out and its moisture absorption weight was completely measured to determine the moisture absorption rate.

As is clear from the comparison between Examples and Comparative Examples, the binder resin was contained in an amount of 10% by weight based on the clutch facing,
The content of C1-8Q knee in the clutch facing is 0.21n9 or less per 1ψ of the clutch facing, and the content of sodium nitrite is 1.0 to 7.0 per 14 clutch facings. By setting the pH of the wear powder to 6 to 9 and suppressing the moisture absorption rate to 10% by weight or more, a clutch facing with good shudder resistance and improved rust prevention can be obtained.

The clutch facing obtained by the present invention has improved rust prevention without impairing the friction characteristics, and is therefore an industrially extremely effective latch facing.

15-

Claims (1)

[Scope of Claims] 1. Apply binder resin to clutch facing of 10
Contains ~20% by weight, C/- in clutch facing
The content of and SO'4- is 0.2 or less per 1y of clutch facing, and 1.0 to 7.0η of sodium nitrite is contained per 1z of clutch facing.
And the pH of the wear-resistant powder in the clutch facing is 6 to 9.
A clutch facing with improved anti-corrosion properties and a moisture absorption rate of 10% by weight or less. 2. A clutch facing with improved rust prevention properties according to claim 1, wherein the binder resin is a formaldehyde condensation resin.