JPS58121325A - Clutch facing having improved rust preventive property - Google Patents

Abstract

PURPOSE:To obtain the clutch facing having excellent judder-resistant property and improved rust preventive property by preparing the quantity of a binder used and the state of curing of the binder indicated at the rate of extraction of methanol under predetermined conditions and bringing the pH of abrasion-resistant powder to 6-10. CONSTITUTION:Resin for the binder to which a component which can be extracted by methanol is used by 8-15wt% is made contain to the clutch facing by 10-20wt%, and the pH of abrasion-resistant powder in the clutch facing is brought to 6-10. The judder-resistant property of the resin for the binder is inferior when the resin is used to the clutch facing by a value less than 20wt% in the resin, and the state of curing of the resin is improper when the component which can be extracted by methanol is used to the resin section for the binder within a range except the range of 8-15wt% and the component is undesired to judder-resistant property in the component. When the pH of abrasion resistant powder in the clutch facing is less than 6, the formation of nitric ions is increased, and rust tends to be generated easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a friction material and a clutch facing having improved shudder resistance and rust resistance.

Clutch 7 Acing is made of 9 asbestos and glass fiber.

Fibrous substances such as potassium titanate fibers, starch fibers, polyimide fibers, abrasion-resistant powder made of cured phenolic resin, and other noodle machine or organic modifiers are used as constituents, such as phenolic and melamine. It is molded using a formaldehyde condensation type resin binder such as

The nine clutch facings manufactured in this manner are important parts of automobiles and are required to have excellent wear resistance, shudder resistance, etc. during driving. Furthermore, during long-term storage, the clutch 7 acing and the mating material (flywheel or pressure plate) come into close contact.

Even in such a state, there must be no rust between the clutch facing and the mating material, and smooth latching operation must be possible even when starting use after long-term storage.

However, in actual clutch facing.

As mentioned above, this is a molded product made from a composite material, and in order to emphasize shudder resistance, the content of binder resin was reduced, which resulted in rust occurring between the parts and the mating material, making clutch operation difficult. may become rusty. Of course, in order to prevent these adverse effects, molded products are treated with nitrite-based rust preventive agents, but depending on the conditions of use, satisfactory results may not always be obtained.

The inventors of the present invention conducted a thorough investigation into the cause of the occurrence of # marks, and found that the source was asbestos, anti-wear powder, etc., which are raw materials for clutch facings (J-).

So4'-, formic acid, etc. promote rusting, and 4I, when the pH of the clutch facing when absorbing moisture is less than 6, rusting is likely to occur, and the rust preventive effect of rust preventive agents such as sodium nitrite is inhibited. I discovered that.

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

As a result of detailed research into the rusting of the clutch 7 acing, including investigation of the rust-causing substance, the present inventors were able to obtain a clutch facing with excellent shudder resistance and improved rust resistance.

1 The present invention contains 10 to 20 parts by weight of a binder resin containing 8 to 15 parts by weight of components extractable with methanol relative to the binder resin, and reduces wear-resistant powder in the clutch facing. pH6~
This invention relates to a clutch facing with improved rust prevention properties.

In addition to the above-mentioned components, the clutch 7 acing of the present invention contains a fibrous substance, a wear-resistant powder, etc. Asbestos, glass fiber, and potassium titanate-based fibers are used as the fibrous substance, and phenol is used as the wear-resistant powder.

Alkylphenol, cashew shell oil-based resin cured products, etc. are used.

As binder resins, phenol/formaldehyde ml alkylphenol/formaldehyde resin, melamine/formaldehyde resin, benzoguanamine/formaldehyde resin, do resin, urea/formaldehyde resin,
Formaldehyde condensation resins such as alcohol-based amino resins, furan-formaldehyde resins, and ketone formaldehyde resins, mixtures thereof, and cocondensation resins thereof can also be used. Furthermore, styrene,
Rubbers such as butadiene, rubber, and acrylonitrile rubber can also be used in combination, but formaldehyde condensation resins are preferred from the viewpoint of heat resistance and abrasion resistance properties of the rubber facing. This binder resin is 1% for the clutch facing.
The weight range is from 0 to 20 weight, and if it exceeds 20 weight, the shudder resistance will be poor, and if the iD is less than 10 weight, the function as a clutch facing will be poor.

The amount of components extractable with methanol is in the range of 8 to 15% by weight relative to the binder resin, and outside this range, the resin will not be in an appropriate cured state and will be unfavorable for shudder resistance. The content of components extractable with methanol can be adjusted by changing the type of binder resin and curing conditions. In the case of formaldehyde condensation resins, suitable curing accelerators may also be used.

The amount of components extractable with methanol is determined by extracting the clutch facing in a Soxhlet extractor under methanol reflux.

In the clutch facing of the present invention, the wear-resistant powder in the clutch facing has a pH of 6 to 10.
During the manufacturing process of the clutch 7 acing, if an anti-wear powder with a pH of 10 is used or an acidic anti-wear powder with a pH below 7 is used.

Treatment with alkaline substances 9 For example, adding alkaline substances such as sodium carbonate and magnesia to yarn, etc., or using aqueous solutions of these alkaline substances to adjust the pH to 6 to 10.
The range of

Wear-resistant powder has a pH of 6 to 10 on clutch facings.
pH 6 is fine as long as it is within the range of pH 6.
There is no need to use it as ~10.

It is confirmed that the wear-resistant powder in the clutch facing has a pH of 6 to 1O by separating the wear-resistant powder in the clutch facing and measuring its pH.

If a sodium nitrite-based rust inhibitor is used at a pH below 6, nitrite (IJ) will be depleted as a result of a chemical change, and some nitrate ions (N) will be produced.

In such a system, it can be determined whether the pH is within the range of 6 to 10 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 10, the production of nitrate ions is extremely small.

The amount of nitrate ions produced can be measured using ion chromatography, etc., and the amount of sodium nitrite destroyed can be measured.

The content of nitrite ions can be measured and confirmed using Ion Chroma Dog 2F.

In the present invention, the wear-resistant powder in the clutch facing is p
The pH range is from 6 to 10, and when the pH is less than 6, a large amount of nitrate ions are likely to occur. Furthermore, if the pH exceeds 10, 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.

As a method for preventing clutch 7 acing obtained in the present invention, a known method can be used.

For example, a method can be used in which the clutch facing is immersed in a nitrite-based rust preventive solution and then dried.

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

Example 1 Memelamine was added to asbestos yarn [stone 480 weight or more, cashew shell oil-based resin cured product (phenolic resin cured product >10 weight 1 weight (extracted water pH: 4.5), stapler and metal wire 10 weight -)] Resin Hitachi Chemical VU-5711N) and 7
A mixture of water and methanol solution of enol resin (VP-51IN) was impregnated with a solid content of 20% by weight, then dried, heated (150°C), and pressurized (50Kff/
l:x'') and cured in a mold for 30 minutes.The surface was then polished to obtain Clutch 7 Acing (5).

Next, this clutch facing was impregnated with an aqueous solution containing 2% by weight (pH 10.5) of triethanolamine (Wako reagent grade 1) for 90 minutes to perform a neutralization treatment. After this.

The clutch facing was soaked in ion-exchanged water for 90 minutes and then washed with water. After washing with water, it was dried at 70°C for 1 hour to obtain a clutch facing (B). Next, this was immersed in a rust-preventing aqueous solution containing sodium nitrite (Mitsubishi Kasei $1/10 weight) for 1 minute, and then dried at 70°C for 1 hour to obtain a clutch facing (C). When C) was extracted using a Soxhlet extractor under methanol reflux, the amount of components extractable with methanol (methanol extraction rate) was 15% by weight based on the blended binder resin.

The rusting force measured by the clutch facing (C) casting test method is 0 to 0.05 Kff/in''.

NO8″ in clutch facing + C1 after rust test
The content was less than α02 weight. The shudder resistance tested on an actual vehicle was poor. Wear-resistant powder was taken out from the clutch 7 acing, added with 1Qm of water, heated and boiled. After extraction, the pH was measured at room temperature and found to be 6.
It was 5.

Example 2 Asbestos yarn (stone 1s 70wt., alkali washed and water washed cashew hardened product 20wt.).

A mixture of water and methanol solution of melamine resin (VU-5711N manufactured by Hitachi Chemical Co., Ltd.) and phenol resin (VP-511N manufactured by Hitachi Chemical Co., Ltd.) was impregnated with a solid content of 10% by weight along with a hardening accelerator and Dry and heat (150°C).

Cured for 30 minutes in a pressurized (501'4 f/cnl) mold.

Thereafter, the surface was polished to obtain a clutch facing (■).

Next, this clutch facing () was subjected to antirust treatment with sodium nitrite in the same manner as in Example 1 to obtain a clutch facing (E). This clutch facing (E
) methanol extraction rate is 8% by weight based on the nine binder resins. The rusting force of the clutch facing (E) was O ~ 0.05 Kff/in'', and the NO3- content in the clutch facing (E) after the rusting test was less than α02 weight. The shudder resistance was excellent.The pH of the wear-resistant powder was measured in the same manner as in Example 1, and the pH was 7.0.

Example 3 Clutch facing (3) obtained according to Example 1
was immersed in a heated aqueous solution (approximately 70° C.) containing 2 g of sodium carbonate (pH 11) for 90 minutes for neutralization. After this, clean the clutch facing with ion exchange water.
A clutch facing (F) was obtained by immersing and rinsing in water for 0 minutes (40°C) and drying at 70°C for 1 hour. The pH of the wear-resistant powder was measured in the same manner as in Example 1, and the pH was found at nine points.
Fi 6.7 and nine.

This product was subjected to the same rust prevention treatment as in Example 1.

A clutch facing (G) was obtained. The methanol extraction rate of clutch facing (Gl) is 15% by weight relative to the blended binder resin. The rusting force of this clutch facing (G) is OK g'/in''.

The amount of Non- in the clutch facing 0) after the rust test was 6 and 9 with α02 weight or less. The shudder resistance tested on an actual vehicle was good, with a score of 6/9.

Comparative Example 1 Clutch facing (5) obtained according to Example IK
After that, the same anti-rust treatment as in Example 1 was applied without performing "neutralization and water washing treatment", and a clutch 7A was obtained.

When the pH of the wear-resistant powder was measured in the same manner as in Example 1, the pH was 5.1. The methanol extraction rate of this clutch facing round is 15% compared to 9 binder resins.
The weight was -.

The rusting force of clutch 7 acing circle is 6~a Kti f
/In'', and red rust had occurred on the entire surface.

The NO content in the clutch 7 acing circle after the rusting test was determined by α5 weight. The shudder resistance tested on an actual vehicle was good.

Comparative Example 2 A clutch facing (I) obtained in the same manner as in Example 2 was subjected to the same rust prevention treatment as in Example 1, except that a binder resin containing no curing accelerator was used, and a clutch facing (J ). This clutch facing (J
) had a methanol extraction rate of 3% by weight based on the blended binder resin. The rusting force of the clutch 7 x sink (J) was relatively good at 0 to α05 Kff/in, but the shudder property tested on an actual vehicle was poor with shudder occurring.After the rusting test The N01 content in the clutch facing (J) was less than α02 weight.

<Rust test method> Cut the clutch facing into 1-inch square pieces while keeping it thick, and attach it to cast iron FC-25 of the same size + 2"
Apply a load of 11'/in''. Place the product in a constant temperature and humidity chamber (50°C, 90°RH) and in a dryer (60°C).
It was incubated for a total of 15 days in 2 hour cycles. After standing still, the load was removed, and the adhesion force in the shear direction between the clutch 7 acing and cast iron PC-25 was measured using a spring scale to determine the rusting force.

As is clear from the comparison between Examples and Comparative Examples, the hardened part of the binder, which is indicated by the amount of binder used and the methanol extraction rate, is maintained under certain conditions, and the anti-wear powder in the clutch facing is adjusted to pH 6 to IOK. As a result, 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 properties without impairing the friction characteristics, making it an industrially extremely effective latch facing.

Agent Patent Attorney: Kunihiko Hayashi

Claims (1)

[Scope of Claims] 1. A component extractable with methanol is contained by weight of 8 to 15% by weight based on the binder resin and 10% to 20% by weight based on the clutch facing of the binder resin. Clutch facing with improved anti-corrosion properties by adjusting the pH of the wear-resistant powder inside to 6 to 10. The clutch facing with improved rust prevention properties according to claim 1, wherein the resin for the λ binder is a formaldehyde condensation resin.