JPH01268725A - Production of friction material - Google Patents

Abstract

PURPOSE:To obtain the title industrially suitable material having excellent friction characteristics, juddering properties, rotary fracture strength, etc., and light weight of product, by impregnating combined yarn of specific sliver yarn and continuous yarn with a binder, drying and molding. CONSTITUTION:(A) A non-asbestos base material such as glass fibers is blended with (B) organic fibers such as acrylic fibers to give slivers, which are twisted to give sliver yarn. The sliver yarn is combined with (C) continuous yarn such as carbon yarn having preferably 3-20mu fiber diameter to give combined yarn, which is impregnated or covered with (D) a binder such as rubber composition or phenolic resin, wound in a twilled state, premolded, then pressed in a mold and molded under heating to give the aimed friction material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing friction materials such as clutch facings and brake linings.

(Prior Art) Conventional methods for manufacturing friction materials 1, such as clutch facings, include a semi-molding method as disclosed in JP-A-49-119044 and a special woven method as disclosed in JP-A-53-27756. is generally known.

Among these methods, the semi-molding method involves impregnating continuous yarns of non-asbestos base materials such as glass fibers and carbon fibers with binders such as inorganic fillers, rubber, rubber compositions containing vulcanizing agents, and thermosetting resins. Or covered.

This is wrapped concentrically or in a twill pattern at a certain angle in the circular direction, then preformed, and then pressed.

This is a method of heat forming.

On the other hand, the special woven method involves blending the same non-asbestos base material and organic fibers as above and then making a sliver.
In this method, the slivers are further twisted together to form a sliver yarn, and then this sliver yarn is impregnated with a binder such as a thermosetting resin, and the sliver yarn is wound concentrically and preformed, followed by pressurization and heat molding.

(Problems to be solved by the invention) Among these, the semi-molding method has advantages such as good wear resistance and less distortion, but it has the disadvantages of heavy product weight, low 9-turn breaking strength, poor shudder properties, etc. There are drawbacks.

On the other hand, the special woven method generally uses less binder than the semi-mold method, so the weight of the product is lighter.Since the sliver yarn is wrapped concentrically and molded, it has high rotational breaking strength. ), but its wear resistance is poorer than that of the semi-mold method.

Since the yarns are wound concentrically, the yarns have weak glabella strength and are easily distorted.

(Means for Solving Problem 81) As a result of various studies in view of the above-mentioned problems, the inventors of the present invention have discovered that K. 2. Strength, friction properties 9. Problems related to weight were resolved and 9% properties were found to be improved.

The present invention involves blending a non-asbestos base material with organic fibers to create a post-mortem sliver, then twisting the sliver to form a sliver yarn, and then combining the sliver yarn with other continuous yarns to form a nine-merged yarn. Impregnated or coated with agent.

The present invention relates to a method of manufacturing a friction material which is then dried and molded.

In the present invention, non-asbestos base materials include glass fibers, carbon fibers, steel shreds, etc. other than asbestos.

The organic fiber used in the present invention is natural cotton.

Synthetic fibers such as cloth, acrylic fibers with excellent heat resistance, and aramid fibers are used.

In the present invention, in the sliver yarn, friction modifiers such as hardened cashew shell oil, cork powder, and wood flour, brass wire,
Metal wires such as zinc wires and copper wires are added.

On the other hand, continuous yarn is a convergence of non-asbestos base materials and/or organic fibers such as glass fibers, carbon fibers, and steel shattered fibers with a fiber diameter of 3 to 20μ, and can be formed by roving or crimping. There is a yarn that has been processed to have a high bulk that has a certain shape. Further, the continuous yarn may be used as a single yarn, or a twisted yarn obtained by twisting a plurality of single yarns together, and there is no particular restriction. Friction modifiers such as hardened cashew shell oil, cork powder, and wood flour, and metal wires such as brass wire, zinc wire, and steel wire are added to the continuous yarn as necessary.

As a binder, inorganic filler and NBR rubber are used.

Rubber compositions such as SBR rubber, vulcanizing agents, vulcanization aids, and vulcanization accelerators, and thermosetting resins such as phenolic resins, melamine resins, and epoxy resins are used. When a rubber composition is used as the binder, it is preferable to pre-treat the thermosetting resin before impregnating and coating with the rubber composition. As the filler of the rubber composition, barium sulfate, calcium carbonate, magnesium carbonate, alumina, graphite, carbon, etc. are used, and as the vulcanizing agent, for example, sulfur is used.

The method of impregnating or coating with the binder is not particularly limited, and any conventionally known method may be used. There are also no restrictions on the forming method, but 2 For example, a sliver yarn impregnated or coated with a binder and a continuous yarn are wound in a twill pattern at an angle in the circumferential direction, preformed, and then placed in a mold. It is preferable to pressurize and heat to shape.

It is preferable that the continuous yarn content be 4 to 40% by weight relative to the friction material, since this provides high rotational breaking strength, a light product weight, and excellent shudder properties.

The content of the binder is 10 to 80% by weight based on the friction material.
If so, it is preferable because it has a high rotational fracture strength and is excellent in wear resistance and strength.

(Example) The present invention will be explained in detail below.

Example I Chopped strands of E glass fiber with a length of 4 cm (manufactured by Fuji Fiber Glass, trade name FE8-13)
-0408) 60% by weight and 40% by weight of Souf (manufactured by Toho Rayon, trade name Tobis) were mixed, and this was applied to a carding machine to make a sliver, and then sliver 8
Cashew shell oil hardened product (manufactured by Tohoku Kako, trade name F) to 0% by weight
20 wt. Thereafter, the three yarns obtained above and one brass wire (manufactured by Narita Shinsen) with a diameter of 0.16 n+sa were twisted together to obtain a sliver yarn.

On the other hand, a continuous glass yarn (manufactured by Fuji Fiberglass Co., Ltd., trade name: FEB-1450-0990) having a diameter of 6 μm was converged and subjected to roving processing to obtain a continuous glass yarn (Bl) of 1450 tex.

Next, the two sliver yarns (A) obtained above and the two continuous glass yarns (B) were impregnated with phenolic resin (manufactured by our company, not for sale), and then dried at 100°C for 2 minutes to form sliver yarns ( 3) and continuous glass yarn (
A phenolic resin-impregnated yarn was obtained in which 10% by weight of phenolic resin was adhered to B+ in terms of solid content. Thereafter, the rubber composition was impregnated with a diluted solution, and then dried at 100°C for 2 minutes to infuse the phenolic resin-impregnated yarn with 50% by weight of the rubber composition in terms of solid content.
A deposited coated yarn was obtained. What is the diluted solution of the rubber composition?

A rubber composition obtained by mixing 80% by weight of trichlorethylene (manufactured by Kanto Denka Co., Ltd.) with 20% by weight of the solid content of the rubber composition and uniformly dissolving it was used. The rubber composition is 20% by weight of SBR rubber (Japan Synthetic Rubber Backing, trade name J8 1502), 10% by weight of sulfur (manufactured by Hosoi Chemical Co., Ltd., trade name Fine Sulfur), and zinc white (Tokyo Kasei, trade name Zinchua). 6 weights of phenolic resin (
(manufactured in-house, not for sale) 8% by weight, barium sulfate (manufactured by Sakai Chemical, product names B and C) 30% by weight, carbon (manufactured by Tokai Carbon).

A mixture of 10% by weight of calcium carbonate (product name: Sheath) 3), 10% by weight of calcium carbonate (manufactured by Hitachi Kansuiseki, product name: Ultrafine Powder), and 6% by weight of graphite (homemade, not for sale) was used.

Next, this coated yarn was wound in a twill pattern at an angle of 30 degrees with respect to the circumferential direction, and preforming was performed. This is then heated to a pressure of 150 k in a mold set at a mold temperature of 160°C.
Pressure and heat molding were carried out at 180g/am".
Post-curing was carried out at ℃ for 2 hours.

Furthermore, the surface is polished to an outer diameter of 200 m + a x inner diameter of 130 x
A clutch facing body with a thickness of 3.5 mm was obtained.

The content of continuous glass yarn (B) in the naori latch facing (5) was 20% by weight.

Comparative Example 1 Example 1 was applied to two sliver yarns (A) obtained in Example 1.
The coated yarn was impregnated with the same 7-enol resin as used in the above, and then dried at 100° C. for 2 minutes to obtain a coated yarn in which 30 weight solids of phenol resin was adhered to the sliver yarn. The coated yarn was then concentrically wound and preformed.

The clutch facing [B
I got l.

Comparative Example 2 The same rubber as that used in Example 1 was prepared by preparing two continuous glass yarns (obtained in Example 1) and one brass wire (manufactured by Narita Wire Co., Ltd.) with a diameter of 0.16 mm. impregnated with a diluted composition;
The coated yarn was then dried at 100° C. for 2 minutes to obtain a coated yarn having 60% by weight of the rubber composition adhered to the continuous glass yarn field (solid content). Thereafter, preforming was performed in the same manner as in Example 1.

Clutch facing fc was then applied in the same manner as in Example 1.
) was obtained.

Example 2 Continuous glass yarn obtained in Example 1 (B170% by weight)
Tofu (manufactured by Toho Rayon, product name: Tobis) 30% by weight
A continuous yarn fC of 3000 tex is twisted with
) was obtained.

Next, one continuous yarn (C) and one sliver yarn (A) obtained in Example 1 were arranged and impregnated using the same material as in Example 1 and in the same manner as in Example 1. , dried and molded to obtain a clutch facing (■).

Nine consecutive yarns (in Naori latch facing (D)
The content of C1 was 28% by weight.

Next, various tests were conducted on the clutch facings obtained in each Example and Comparative Example. The results are shown in Table 1.

Table 1 The test conditions are as follows.

■ 250°C pliers test: Tested 10,000 times at 250°C using an inertial dynamotister.

■ Clutch interface for two-wheel drive passenger cars.

The longitudinal vibration acceleration was measured during the first start.

■ Rotational fracture strength: Measured after being held at 200°C for 5 minutes.

As is clear from Table 1, the clutch facings according to the embodiments of the present invention are excellent in all characteristics. On the other hand, it can be seen that the conventional (comparative example) clutch facing has a defect in either friction characteristics, shudder two-turn fracture strength, or density.

(Effect of the invention)

Claims (1)

[Claims] 1. A sliver is made after blending a non-asbestos base material and an organic fiber, the sliver is further twisted to form a sliver yarn, and then the combined yarn, which is a combination of this sliver yarn and another continuous yarn, is impregnated with a binder. Or a method for producing a friction material, which comprises coating, followed by drying and molding.