JPH0735834B2 - Rubber mold clutch facing manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a rubber mold clutch facing, and more specifically, it has excellent judder performance, excellent temperature dependence of friction coefficient (μ) in stable period, and wear. TECHNICAL FIELD The present invention relates to a method for manufacturing a rubber mold clutch facing having improved properties.

The present invention relates to an improvement in a method for manufacturing a clutch facing of a clutch disc for connecting and disconnecting power transmission used in an automobile or the like, and the clutch facing is a clutch for connecting or disconnecting power between an engine and a transmission in an automobile or the like. Used as a disk component.

[Prior Art] As a friction material used for a conventional clutch facing, one having a glass long fiber or a glass cloth as a base material is generally known. Further, there is also known a vehicle friction material characterized by using a bulked glass fiber such as glass fiber as a base material (JP-A-56-167934).
Issue).

Another conventional friction material is glass fiber chopped strands or milled fibers with a length of 1-6 mm.
There is also known a product obtained by blending a synthetic rubber and a synthetic resin using the above as a base material, molding the mixture, and then firing the mixture (JP-A-51-87549).

Further, as a conventional dry friction material composition used for clutch facing or the like, a binder composition, a combination of pulp-like aromatic polyamide and chopped glass fiber is used, and asbestos having good burst strength and abrasion resistance is used. Those that do not contain are known (Japanese Patent Laid-Open No. 59-45383).
Issue). Furthermore, as the glass fiber used here
Also disclosed are chopped strands having a length of 2.54 to 25.4 mm.

[Problems to be Solved by the Invention] As a conventional method for manufacturing a clutch facing, generally, a base material is impregnated with a resin, pre-cured, pre-cured with rubber, further pre-cured, wound and molded. It is manufactured by heat-treating, then polishing, and optionally rust-proofing. Further, since long glass fibers and glass cloth are used as the base material, there are many processes and the cost is high. Further, since the long glass fiber is used for this clutch facing, this fiber is exposed on the surface, so that there is a problem that the influence of the glass on μ is great and the judder performance is bad.

Further, in the above-mentioned JP-A-56-167934, when the rubber is attached to the glass fiber that has been subjected to the bulking process, a covering or dipping is often performed, and in this case, the degree of freedom of the blending amount of the base material and the rubber is high. There was a problem that it was small and lacked in uniformity.

Further, in the case of JP-A-51-87549, glass fibers having a fiber length of 1 to 6 mm are used, and since this is too short, there is a problem that the rotational burst strength is weak.

Further, in the case of producing a clutch facing using the dry friction material composition disclosed in JP-A-59-453835, as the binder, nitrile rubber and thermosetting phenolic resin are used in the examples, both of which are powders. In addition, the composition is disclosed as being all solid ingredients and is described as being mixed in a sigma mixer to form a dry mixture.

When the composition is produced using this composition, it is only in a liquid state at the time of molding due to powder molding, and the dispersibility of the fiber is poor, and the resin and the rubber, particularly the rubber uniformly and sufficiently cover the fiber. It is not configured to protect. Although the glass fiber used is disclosed to be 2.5 to 25.4 mm, it is said that the range of 1 to 6 mm is more preferable in the range of practical examples. However, in this known technique, the resin is first impregnated into the fiber and then the rubber. Therefore, especially one rubber
It cannot be said that it shows sufficient friction material properties because it does not sufficiently enter into one fiber.

The present invention has been made in view of the above viewpoint, and an object thereof is to provide a method for manufacturing a rubber clutch facing having excellent judder performance, improved temperature dependence of the stable period μ, and further improved wear resistance. And

[Means for Solving the Problems] The production method of the present invention comprises a base material containing inorganic fibers, a rubber agent,
A method for producing a rubber mold clutch facing composed of a reinforcing agent, an inorganic filler and a vulcanizing agent, wherein the inorganic fiber is a short fiber having a length of 7 to 30 mm, and each composition except at least the inorganic fiber. After mixing the materials and then swelling the rubber agent by adding a solvent for the rubber agent, at least the inorganic fibers are mixed and kneaded to carry out kneading rubber sheet, after which precuring, molding and heat treatment are performed. And According to this manufacturing method, for example, the first
The rubber mold clutch facing of the invention can be manufactured.

The length of the inorganic fiber is set to 7 to 30 mm when the burst strength is weak when the length is less than 7 mm, and when the length exceeds 30 mm, the fibers are too long at the time of feeding the rubber sheet, and thus the entanglement of the fibers in the rubber does not occur. This is because the sheets are too large to print out properly. That is, within the scope of the present invention, it can be said that the length is the longest length that allows good sheet ejection while maintaining the burst strength, and that the fibers can be uniformly dispersed without breaking.

In the production method of the present invention, a compounding agent component having the following compounding ratios can be used. That is, with respect to 100 parts by weight of the rubber agent, the inorganic fiber is 25 to 150 parts by weight, the reinforcing agent is 10
~ 30 parts by weight, 100-200 parts by weight of inorganic filler, vulcanizing agent
15 to 30 parts by weight.

As the inorganic fiber, one kind or two or more kinds of glass fiber, ceramic fiber, silica fiber, alumina fiber and the like can be used as in the conventional case. Carbon black or the like can be used as the reinforcing agent. Inorganic fillers include
Calcium carbonate, barium sulfate, diatomaceous earth, molybdenum disulfide, lead sulfide and the like can be used.

As the rubber agent, SBR, NBR, EPDM, NR, IR, BR, IIR
Etc. can be used. Sulfur as the cross-linking agent,
Zinc oxide or the like can be used.

Further, in the present invention, in addition to the above, a crosslinking aid, a resin binder, an organic fiber or an organic filler may be contained.

As this cross-linking aid, active zinc white or cashew-modified resin or the like can be used. As the vulcanization accelerator, TURAM-based TT, TS, sulfenamide-based CZ, DZ and the like can be used.

As the resin binder, a phenol resin-based one, a melamine resin-based one, or the like is used, and usually a phenol resin-based one is used. Further, as the binder, a modified phenol resin modified with cashew nut oil, poly (vinyl butyral), vegetable oil, melamine, epoxy compound or the like may be used. The unmodified phenolic resin is preferable in that the fade phenomenon does not easily occur.

As the organic fiber, a fiber having heat resistance is desirable, for example, aromatic polyamide fiber, polyimide fiber,
One or two or more of polyamideimide fiber, phenol fiber, and carbon fiber can be used.

As the organic filler, cashew dust and other various organic compounding agents can be used.

[Examples] Hereinafter, the present invention will be described with reference to Examples.

In this Example, Table 1 shows the kinds of compounding agent components and the compounding ratio of the compounding agent components as shown in Table 1.
As the compounding agent component, SBR as a rubber agent, carbon black "HAF-70" (manufactured by Asahi Carbon Co., Ltd.) as a reinforcing agent, calcium carbonate as an inorganic filler, glass fiber as an inorganic fiber, sulfur as a crosslinking agent, and Activated zinc white and cashew-modified resin were used as the vulcanization aid, and sulfenamide-based CZ and TS were used as the vulcanization accelerator. The glass fiber used is 30 mm in Examples 1 to 4 and 6 mm in Comparative Example 1.
As Comparative Example 2, a long fiber was used.

Clutch facings of this example and comparative example 1 were manufactured by using the components having the above-described composition as follows. In addition, about the comparative example 2, it manufactured similarly using the glass long fiber.

First, all of the compounding agent components excluding the vulcanizing agent and the glass fiber were weighed and compounded in the amounts shown in Table 1, and kneaded with a rubber using a pressure kneader, and then vulcanized using a nipple roll. The agents were blended and kneaded. Then, these were used to swell the SBR using toluene as a rubber solvent.

Next, a predetermined amount of glass fiber was introduced using an opening kneader and kneading was carried out to obtain a kneaded rubber sheet. Then, precure was performed under the condition of 60 to 90 ° C., and solvent removal was also performed. Then a predetermined disc shape (outer diameter 200 mmφ,
Punching to an inner diameter of 140 mmφ and a thickness of 3.0 mm)
Heat treatment was carried out by pressure molding at a temperature of 90 ° C. and a pressure of 90 kg / cm ² .
Then, this was heat-treated under the condition of 230 ° C. × 8 Hhs, and further the surface was polished and rust-proofed to manufacture each clutch facing having the same shape.

Then, a full size dynamo test was performed to evaluate the performance of the products of Examples 1 to 4 and Comparative Examples 1 and 2. The conditions for this dynamo test are I = 0.2 kg · m · sec ² , n = 1800 r
pm, N = 2000 times (the number of engagements at 300 ° C.). In addition, as the evaluation performance, initial μ, minimum μ, stable period μ, wear resistance, burst strength, judder performance of actual vehicle,
The results are shown in Table 2. The burst intensity is
Performed at 200 ° C.

In Examples 1 to 3, when the glass fiber having a glass fiber of 30 mm was used, all performances were good. Further, in Example 4, the glass fiber was 30 mm and the cashew-modified resin was not blended, but the minimum μ was slightly small and slipping tended to occur, but other performances were good.

On the other hand, in Comparative Example 1, the burst strength was small, in Comparative Example 2, the stable period μ showed a large value, and the actual vehicle judder performance also showed a large value, indicating that the judder performance was not excellent.

From the above, when using a glass fiber of 30 mm to swell the rubber with a solvent, and when kneading by adding short fibers with an open kneader, this short fiber can be broke well and a rubber sheet can be taken out well. Since the SBR was well coated on the surface, the performance as a friction material was all good except for the minimum μ of Example 4.

[Effects of the Invention] The production method of the present invention is produced by using inorganic fibers having a length of 7 to 30 mm and swelling the rubber agent with a solvent, and then adding and kneading the fibers. Therefore, according to the present manufacturing method, since the effect that the inorganic short fibers are uniformly coated with the rubber is further increased, the influence of the inorganic fibers on μ is further reduced, and therefore the clutch facing in which the judder performance is further improved can be manufactured.

Further, in the present manufacturing method, since the inorganic short fibers are uniformly coated with rubber, it is possible to manufacture the clutch facing in which the inorganic fibers do not fall off and the abrasion resistance is further improved.

Further, in the present manufacturing method, the rubber used is swelled with a solvent, and then predetermined short fibers are added to manufacture. That is, in the present invention, sufficiently loosened short fibers such as those obtained by loosening long fibers are used, and after swelling with a solvent, short fibers are mixed under kneading and kneading conditions to carry out kneading rubber sheet delivery. Therefore, rubber is more than enough adhered to the surface of each fiber. On the other hand, in the friction material disclosed in JP-A-59-453835, glass fibers having a diameter of 2 to 25 mm can be used. However, resin is mainly used as the binder. In addition, the rubber and phenolic resin used are all solid components mixed to form a relatively uniform dry mixture, ie powder molding. Therefore, although it is possible that it will be in a liquid state at the time of molding,
Under these conditions it is difficult for rubber to adhere well around the glass fibers. Therefore, it is considered that both structures of the manufactured clutch facing are basically different. Therefore, the clutch facing produced by the present invention exhibits sufficiently good friction material characteristics unlike this reference. That is, the rubber mold clutch facing obtained by the present invention is composed of short fibers having a length of the inorganic fiber of 7 to 30 mm and each of the compounding components of the inorganic fiber and the rubber agent having a predetermined mixing ratio. There is. Therefore, in the present clutch facing, since the inorganic short fibers are easily uniformly coated with rubber, the influence on μ of the inorganic fibers is reduced, so that the judder performance is improved and the falling of the inorganic fibers is reduced, and the abrasion resistance is improved. improves.

Claims (1)

[Claims] 1. A method for producing a rubber mold clutch facing comprising a base material containing inorganic fibers, a rubber agent, a compulsory agent, an inorganic filler and a vulcanizing agent, wherein the inorganic fibers have a length of 7 to 30 mm. It is a short fiber, at least each compounding agent component excluding the inorganic fiber is mixed, then a solvent for a rubber agent is added to swell the rubber agent, and then at least the inorganic fiber is compounded and kneaded to carry out kneading a rubber sheet. And then pre-cured, molded, and further heat-treated, a method for producing a rubber mold clutch facing.