JPH0539365A - Production of clutch facing - Google Patents

Abstract

PURPOSE:To produce a clutch facing which exhibits a high burst strength and little warpage by coating and impregnating chopped strands of a glass fiber with a friction-controlling agent, molding the strands, and thermally treating the resulting molding. CONSTITUTION:A fibrous substrate consisting of chopped strands 3 of a glass fiber is coated and impregnated with a binder 1 contg. a friction-controlling agent on a coating and impregnating machine, then molded, and thermally treated to give the objective clutch facing. Pref., the agent contains a melamine dust to reduce the wt. of the facing and to improve the burst strength. The binder is prepd. by mixing specified amts. of a thermoplastic resin, a synthetic rubber, the agent contg. the dust, and a solvent. A horizontal coating and impregnating machine is pref. since it enables a uniform coating, hardly generates stress in the strands, hence keeps the strands orderly arranged, and hardly allows the binder to flow after being applied.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for manufacturing a clutch facing.

[0002]

2. Description of the Related Art In recent years, the production volume of automobiles has increased remarkably, supported by the booming economy, and in particular, sales of high-output vehicles such as large vehicles, turbo vehicles, and 4WD vehicles have been favorable. Along with this, as clutch facings to be mounted on high-powered vehicles, the emergence of important parts of automobiles with improved burst strength (rotational breaking strength) and less warpage is strongly desired.

The current mainstream of clutch facings is the semi-mold type, which is a yarn made of glass fiber or a composite of glass fiber and organic fiber in the form of a string, a thermosetting resin, rubber or rubber. A rubber composition containing a vulcanizing agent and various friction modifiers are evenly mixed with a solvent to apply a binder, and then the solvent is removed and wound into a predetermined shape, followed by heating and pressing, post-curing, polishing and rivets. It is manufactured through the process of drilling.

[0004]

However, the clutch facing produced by the above-mentioned method is different in the type of yarn to be used, the compatibility between the yarn and the binder, the impregnation time of the binder into the yarn, and the binder-coated yarn. It is very difficult to manage the winding method of the rubber, and the thermal properties of the rubber used,
It is difficult to improve the burst strength and reduce the warp due to problems such as a long manufacturing process. Therefore, as measures for improving the burst strength, JP-A-62-266237 and JP-A-1 are available.
Japanese Patent Laid-Open No. 210631, Japanese Patent Laid-Open No. 2-36292, and the like have been proposed, but all of them have problems such as a long manufacturing process and easy occurrence of warpage.

Further, there are patent applications closely related to the present invention, which are Japanese Patent Laid-Open Nos. 62-86820, 63-56534, and 63.
-140133 and JP-A-63-251432. In JP-A-62-86820, the glass fiber of the base material is a filament, and the basis weight is 1,000 g / m ² , and the thickness is 2-3 mm.
Since it is thick and clogged, the particles of the friction modifier contained in the binder do not penetrate into the inside of the base material, and the friction coefficient tends to be unstable. Further, when a relatively large amount of friction modifier is added, a layer of the base material and the friction modifier is formed, and the interlaminar strength of the layer is decreased, so that the burst strength is also decreased. The glass fiber disclosed in JP-A-63-56534 has two or more glass fibers.
The length is as long as 20 mm, and the basis weight is good at around 100 g / m ^2. However, since the filament is used, the non-woven fabric is clogged and it is difficult to impregnate the mixture containing the particulates even into the inside of the base material. When forcedly impregnated, randomly arranged fibers face the flow direction of the resin and lack isotropy, resulting in deterioration of strength and warpage. In Japanese Patent Laid-Open No. 63-140133, chopped strands are used to manufacture a friction material for a brake by molding. However, the clutch facing manufactured by molding has a low burst strength and cannot be applied to high-power vehicles. In Japanese Patent Laid-Open No. 63-251432, the base fiber is a non-woven fabric, and the particles of the friction modifier contained in the binder do not penetrate into the inside of the base material, resulting in a non-uniform structure and burst strength. It is not possible to expect improvement of

The present invention provides a method of manufacturing a clutch facing which has a simple manufacturing process, is excellent in burst strength, and has less warp.

[0007]

According to the present invention, a chopped strand of glass fiber is used as a base fiber, and a binder containing a friction modifier is impregnated and applied to the base fiber by using an impregnation coater, followed by molding and heat treatment. The present invention relates to a method for manufacturing a clutch facing.

In the present invention, the chopped strands of glass fibers used are such that the individual fibers are randomly oriented and the length is preferably 1 to 10 cm. The filament diameter and hardness, the number of filaments forming the strands. The type of surface treatment agent is not limited. Further, it is not prepared as chopped strands from the beginning, and for example, glass rovings may be cut into the above lengths and randomly oriented for use. The brand of chopped strands is not limited, but CS6PE-22 manufactured by Nitto Boseki Co., Ltd.
1, CS6E-401, CS6PB-542, CS6P
E-231, CS6PE-401, CS6PE-40
3, CS6PE-471, CS6PE-472, CS6
PE-422, CS50E-221, CS25E-22
1, CS13E-221, CS6E-221, CS3E
-221, CS6PA-401, CS25Z-700, etc. are used.

The resin component in the binder is not particularly limited, but a thermosetting resin is preferable. The thermosetting resin may be solid, powdery or liquid (if solid or powdery, it is diluted with a solvent before use), for example solid phenolic resin, powdery phenolic resin, solid epoxy resin, liquid phenolic resin. , Liquid epoxy resin is used. Economy, workability,
In consideration of heat resistance and adhesiveness with chopped strands, a solvent-diluted type such as powdered phenolic resin or powdered modified phenolic resin is preferable. As the powdery phenolic resin, Praiophen J-36 manufactured by Dainippon Ink and Chemicals, Inc.
3, the same J-375, the same J-5510, TD-2040
C, TD-2018, TD-2003, TD-203
3, TD-696, TD-697, TD-787, Sumilite resin PR-12687 manufactured by Sumitomo Bakelite Co., Ltd.
Etc.

In addition, it is 2 to 100 parts by weight of the resin component.
It is preferable to use 40 parts of synthetic rubber because the holding power of the friction modifier is enhanced. There are no particular restrictions on the type of synthetic rubber, for example, Nippol 1041 and 10 of Nippon Zeon Co., Ltd.
42, same 1043, same 1042AL, same 1052J, same 1032, DN201, DN202, DN202H, D
N204, DN206, DN207, DN211, DN
223, DN103, DN115, Clinac 801 manufactured by Polcer, and N220SH manufactured by Japan Synthetic Rubber Co., Ltd. are used. Two or more types of rubber components may be used in combination as necessary. Further, in order to cure the synthetic rubber, a vulcanizing agent, a vulcanization aid, and, if necessary, a vulcanization accelerator are used. As the vulcanizing agent, colloidal sulfur, precipitated sulfur, etc. are used,
Zinc white is used as a vulcanization aid. As the vulcanization accelerator, for example, Nox Cellar M, DM, TT, TET, TS, TRA, P, PZ and BZ manufactured by Ouchi Shinko Co., Ltd. are used.

The friction modifier preferably contains melamine dust (a melamine resin cured, crushed and classified) in order to reduce the weight of the clutch facing and improve the burst strength. The melamine resin used for dust is not particularly limited, but powdery melamine resin is preferable, and examples thereof include S260 and S306 manufactured by Nippon Carbide Co. There are no particular restrictions on the curing conditions for the melamine resin, and the temperature and time at which the melamine resin is completely cured are selected. The pulverization conditions of the melamine resin cured product and the method of adjusting the particle size distribution are also not particularly limited, and usually, they are pulverized by a pulverizer, classified by a sieving machine, and mixed. The particle size of the melamine dust is preferably 10 to 500 μm. Other organic and inorganic friction modifiers used are not particularly limited as long as they improve friction characteristics and do not reduce burst strength, and cashew dust, graphite, carbon black, barium sulfate, calcium carbonate, magnesium carbonate. , Titanium oxide, copper powder, alumina, silica and the like.

The binder is obtained by weighing the friction modifier containing the above-mentioned thermosetting resin, synthetic rubber and melamine dust, adding a solvent and mixing. The amount of the friction modifier in the binder is 100 to 5 with respect to 100 parts by weight of the resin in consideration of the permeability to the chopped strands and the coating property.
00 parts is preferred. The viscosity of the binder is preferably 100 to 800 poises in order to uniformly impregnate the chopped strands and bring out the desired properties. If the viscosity of the binder is too small, in the step of drying the binder-impregnated coated chopped strand to remove the solvent, the viscosity of the binder is too low, and the strand cannot be well impregnated with the binder,
No improvement in burst strength or warpage can be expected. On the other hand, when the viscosity of the binder is too high, the penetrability into the strand and the coatability are drastically lowered, and again, the burst strength and the warp cannot be expected to be improved.

The ratio of binder to chopped strands (% by weight) in the case of impregnation coating is preferably 20/80 to 80/20 binder / chopped strands. When the amount of the binder is small, the binding action is weak and the burst strength is reduced. On the contrary, when the amount of the binder is too large, the organic component becomes excessive and the warp increases.

The coating machine for impregnating and coating the chopped strands with the binder is capable of uniform coating, stress is not easily applied to the chopped strands, and therefore the base fibers are not disturbed, and the binder is not applied after coating. A horizontal type impregnating coater with less flow is preferable. An example of a coating machine is shown in FIGS. 1, 2 and 3.
FIG. 1 shows a horizontal impregnation coater, in which a belt conveyer 7 is operated to feed a film 4 such as polypropylene in the direction of the arrow, the binder 1 is first applied onto the film 4a, and the thickness is adjusted with a knife coater 2. Then, the chopped strands 3 are supplied, a film 4b such as polyethylene is adhered on the chopped strands 3 and is crimped with a crimping roll 5, and a plurality of fine holes for solvent drying are punched with a puncher 6, and then the drying furnace 8 is provided. Send it to dry,
The solvent is removed. Figure 2 is also a horizontal impregnation coating machine,
The chopped strands 3 are impregnated and coated with the binders 1a and 1b from both upper and lower surfaces. FIG. 3 shows a vertical type impregnation coating machine, which is different from the horizontal type impregnation coating machine, in which the film 4 is fed from the lower side to the upper side as shown by the arrow, and the Bebicon 9 is operated to coat the chopped strands 3 from the spraying machine 10. After spraying, press-bonding, and punching on the binder 1, the mixture is fed from the upper part to the drying oven 8 which is adjacent to and parallel to the operating direction of the belt conveyor 7. Molding and heat treatment are performed by known methods.

[0015]

EXAMPLES Next, examples of the present invention will be described.

Example 1 Glass chopped strand (CS13 manufactured by Nitto Boseki Co., Ltd.
E-221, cutting length 12.5 mm) was prepared. on the other hand,
Phenolic resin (TD2040C manufactured by Dainippon Ink and Chemicals)
606 g, synthetic rubber (NBR manufactured by Zeon Corporation, Nippol
1041) finely chopped 172.5 g, sulfur (Hosoi Chemical Co., Ltd.) 30.75 g, zinc oxide (Tokyo Kasei Co., Ltd.) 30.75 g, melamine dust (Nippon Carbide Co., S260) 312 g, cashew dust ( Tohoku Kako Co., Ltd., FF1350) 52.5 g, barium sulfate (Sakai Chemical Co., Ltd.) 105 g, alumina powder (BACO, MA6)
5) 105 g and 55.5 g of copper powder (manufactured by Wako Pure Chemical Industries, Ltd.)
It was taken in a liter metal container, MEK (methyl ethyl ketone) was added as a solvent, and well stirred by a stirrer until Nippol 1041 was completely dissolved. MEK was then added little by little to obtain a binder adjusted to have a viscosity of 350 poise at room temperature. Next, using the horizontal impregnation coater shown in FIG. 1, after uniformly applying the binder 1 to the film 4a,
The chopped strands 3 in which glass fibers were randomly dispersed were impregnated with the binder 1, and a large number of small holes for solvent removal were formed on the film 4b and dried to obtain a binder-impregnated coated base fiber. The weight of the glass component / binder component at this time was 50/50.

Next, after peeling off the film from the binder-impregnated coating base fiber and processing it, it was processed into a donut shape having an outer diameter of 225 mm, and 5 sheets of this were piled up and the temperature was raised to 160 ° C. for 10 minutes with a breath. Pressurize and heat-treat at 200 ° C for 3 hours and 220 ° C for 2 hours in this order to form a 3.7 mm thick molded body, which is further polished to a thickness of 3.5 mm for clutch facing. I made one.

Example 2 A binder-impregnated coating base fiber was obtained in the same manner as in Example 1 except that the horizontal impregnation coating machine shown in FIG. 2 was used for the impregnation coating in Example 1. Processing, molding, heat treatment and polishing were carried out in the same manner as in 1 to obtain three clutch facings.

Example 3 Glass chopped strand (CS25 manufactured by Nitto Boseki Co., Ltd.
Three clutch facings were obtained in exactly the same manner as in Example 1 except that E-221 and a cut length of 25 mm) were used.

Example 4 Three clutch facings were obtained in exactly the same manner as in Example 3, except that the horizontal impregnation coating machine shown in FIG. 2 was used for the impregnation coating in Example 3.

Comparative Example 1 Three clutch facings were obtained in exactly the same manner as in Example 1, except that the melamine dust in Example 1 was replaced with barium sulfate.

Comparative Example 2 Three clutch facings were obtained in exactly the same manner as in Example 1 except that the vertical impregnation coating machine shown in FIG. 3 was used for the impregnation coating in Example 1.

Comparative Example 3 The substrate fiber was replaced with the glass chopped strand of Example 1 and glass roving (E, manufactured by Fuji Fiber Glass Co., Ltd.
Glass) was used. The binder was prepared in the same manner as in Example 1, transferred to the impregnated coating layer, passed through the glass roving, ironed, and dried to remove the solvent.
A binder-impregnated coated base fiber was obtained. The weight of the glass component / binder component at this time was 50/50. Next, the binder-impregnated coated base fiber is wound in a spiral shape, and molding, heat treatment and polishing are performed under the same conditions as in Example 1 to obtain Example 1.
Three pieces of clutch facings having the same size as were obtained.

Comparative Example 4 The method of winding the binder-impregnated coated base fiber in Comparative Example 3 was
Other than changing from spiral to scatter (dispersed),
Three clutch facings were obtained in exactly the same manner as in Comparative Example 3.

With respect to the clutch facings obtained in each of the above Examples and Comparative Examples, an evaluation test of each performance was conducted. The results are shown in Table 1. In the table, the impregnating property is determined by visually observing the degree of penetration of the binder into the base fiber, ⊚ indicates very good penetration, ◯ indicates good penetration, Δ indicates slightly poor penetration, and × indicates poor penetration. The degree of warp (deformation) is visually judged in four stages of large, medium, small and none. The burst strength is the bench test result in an atmosphere of 200 ° C.
It is the average number of rotations (rpm) of the sheet.

[0026]

[Table 1]

As is clear from Table 1, the impregnating coatability of the binder to the base fiber is superior to the roving of chopped strands as the base fiber, and the horizontal impregnating coater is used as the impregnating coater. Be improved by As a result,
The clutch facing of the example has a higher burst strength than that of the comparative example, and the warping (deformation) of the clutch facing is eliminated.

[0028]

According to the present invention, glass chopped strands are used as the base fibers, and the binder is impregnated and coated on the glass chopped strands, so that the clutch facing having a high burst strength and no warp can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an impregnation coating method using a horizontal impregnation coating machine.

FIG. 2 is a diagram illustrating an impregnation coating method using a horizontal impregnation coating machine.

FIG. 3 is a diagram illustrating an impregnation coating method using a vertical type impregnation coating machine.

[Explanation of symbols]

 1 ... Binder 2 ... Knife Coater 3 ... Chopped Strand 4 ... Film 4 ... Crimping Roll 6 ... Puncher 7 ... Belt Conveyor 8 ... Drying Furnace 9 ... Babycon 10 ... Spraying Machine

Claims (3)

[Claims] 1. A clutch facing characterized in that a chopped strand of glass fiber is used as a base fiber, a binder containing a friction modifier is impregnated and coated on the base fiber with an impregnating coater, and then molding and heat treatment are performed. Manufacturing method. 2. The method for producing a clutch facing according to claim 1, wherein the friction modifier is a friction modifier containing melamine dust. 3. The method for producing a clutch facing according to claim 1, wherein the impregnation coating machine is a horizontal type impregnation coating machine.