JPH0434253A - Toothed belt - Google Patents

Abstract

PURPOSE:To obtain a toothed belt, whose wear resistance is improved, by impregnating the inside of a reinforced canvas layer, which coats a tooth part rubber layer, with rubber mix-provided with gas phase growth carbon fiber. CONSTITUTION:The inside of a reinforced canvas layer 7 for coating surfaces of a tooth part rubber layer 3 is mix-provided with VGCF6. This reinforcing adhesive rubber 4 is laminated so that it is provided in a surface at a side brought into contact with at least a pulley of the reinforced canvas layer 7, that is, external surface of the reinforced canvas layer 7. Further by description in detail, adhesive rubber 5 of the reinforced adhesive rubber layer 14 and the VGCF6 are provided not only in the external surface of the reinforced canvas layer 7 but also in its inside and in the side brought into contact with a tooth part rubber layer 3 of the reinforced canvas layer 7, and the reinforced adhesive rubber layer 4 is constituted of these total units.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a toothed belt in which the surfaces of toothed portions are covered with a reinforcing woven fabric.

(Prior art) Conventionally, in order to improve wear resistance, general carbon fibers (short fibers) such as PAN type were mixed in (for example, Japanese Patent Laid-Open No. 5
9-65644), and those to which a lubricant such as graphite is added (for example, see Japanese Patent Laid-Open No. 48-41176) are known.

(Problems to be Solved by the Invention) However, in the case where carbon fiber is mixed, the carbon fiber manufacturing process is complicated and the manufacturing cost increases. In addition, the fiber diameter is large and the dispersibility in rubber is poor. On the other hand, when a lubricant such as graphite is added, since the particle size is very large, the dispersibility is poor and the particles tend to form lumps, making it difficult to obtain uniform performance.

Therefore, although a large amount of compounding is required to obtain the required performance, a large amount of compounding has poor dispersibility and is difficult to obtain uniform performance, resulting in a decrease in the physical properties of the rubber. Desired wear resistance cannot be obtained. That is, the wear resistance of the tooth portion is insufficient, and cracks are likely to occur at the base of the tooth due to wear of the tooth cloth.

In addition, when conventional carbon fibers are mixed in a large amount, the tan δ of the rubber decreases, causing shake phenomena in the low frequency range, and insufficient meshing.
Causes premature lifespan.

The present invention has been made in view of this point, and an object of the present invention is to provide a toothed belt with improved wear resistance.

(Means for Solving the Problems) The present invention is a wear resistance improving agent that is produced by vapor phase pyrolysis of hydrocarbons and growing carbon fibers on a substrate in which a catalyst is dispersed. Carbon fiber (hereinafter referred to as VGCF), preferably a graphitized product thereof, is used.

The invention of claim (1) is based on a toothed belt in which the surface of the toothed rubber layer is covered with a reinforcing canvas layer, and vapor-grown carbon fibers are mixed in the reinforcing canvas layer that covers the toothed rubber layer. The structure is impregnated with rubber.

In the invention according to claim (2), a reinforcing adhesive rubber layer in which vapor-grown carbon fibers are mixed is further formed on the side of the reinforcing canvas layer that contacts the pulley.

(Function) According to the invention of claim (1), the wear resistance of the tooth portion is improved by the VGCF impregnated into the reinforcing canvas layer, and the strength is increased by reducing the wear of the tooth portion. In addition, rubber containing VGCF has a large tan δ, has a vibration-proofing effect, stabilizes the meshing of the teeth, and extends the belt life.

According to the invention of claim ('2J), by the reinforcing adhesive rubber layer laminated on the side of the reinforcing canvas layer that contacts the pulley,
Wear resistance is further improved.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

In Fig. 1 showing the toothed belt, 1 is a tensile cord;
2.3 is the upper and lower upper rubber layer and the toothed rubber layer of the tensile cord 1; 4 is the reinforcing adhesive rubber layer in which VGCF6 is mixed in the adhesive rubber 5; and 7 is the surface of the toothed rubber layer 3. Reinforced canvas layer with VGCF6 mixed inside.

The reinforcing adhesive rubber layer 4 is, as shown in detail in FIG.
The reinforcing canvas layer 7 is laminated so as to be present at least on the side of the reinforcing canvas layer 7 that contacts the pulley, that is, on the outer surface of the reinforcing canvas layer 7. More specifically, the adhesive rubber 5 and VGCF 6 of the reinforcing adhesive rubber layer 4 are applied not only to the outer surface of the reinforcing canvas layer 7, but also to the inside of the reinforcing canvas layer 7 and the side of the reinforcing canvas layer 7 that contacts the toothed rubber layer 3. They also exist, and together constitute the reinforcing adhesive rubber layer 4.

As is well known, the tooth rubber of the tooth rubber layer 3 and the adhesive rubber 5 of the reinforcing adhesive rubber layer 4 are made of chloroprene rubber or hydrogenated NB.
R is used, but is not particularly limited thereto. In addition, necessary additives (usually silica, a methylene acceptor and a methylene donor are used to constitute the so-called HRH formulation, where the methylene acceptor is resorcinol or its derivatives, and the methylene donor is hexamethylenetetramine or its derivatives). derivatives) are used.

Furthermore, the adhesive rubber 5 may contain fillers, softeners,
Additives such as a vulcanizing agent, a vulcanization accelerator, and an anti-aging agent may be included as appropriate.

The canvas constituting the reinforced canvas layer 7 is made of polyamide, polyester, etc., and the weave shape is appropriately selected depending on the purpose.

A well-known method is used to impregnate the canvas constituting the reinforced canvas layer 7 with rubber. For example, a rubber composition may be dissolved in a suitable organic solvent to form a rubber paste and then coated and impregnated using a coating machine such as a roll coater, or it may be impregnated by being immersed in a rubber paste. It is customary. The solvent is usually used in an amount of 600 to 900 parts by weight per 100 parts by weight of the rubber composition.

The amount of VGCF6 added is in the range of 10 to 50 phr, and VGCF6 preferably has a diameter of 0.05 to 1 μm, a length of 0.1 to 10 μm, and an aspect ratio of 1 to 200.

Subsequently, Torayca MLD-
30 (PAN-based carbon fiber milled fiber manufactured by Toshiku Co., Ltd.), physical properties of rubber to which a fired product of VGCF or a graphitized product thereof is added, and a toothed belt manufactured using the same using a well-known method. The results of the belt running test conducted are shown in the following table.

The running test was carried out using belt tooth profile ZA type and tooth pitch 9°525.
1-. A toothed belt with a belt width of 19°0 and 11 teeth and 95 teeth was wound between a driving pulley (rotation speed 600 orpm) and a driven pulley (load power 2.5 PS), and the ambient temperature was 80°C, and the belt was The test was carried out by running the vehicle with an initial tension of 25 kgf.

The William abrasion test was carried out at a load of 3. 62kg, 240
No. Sandpeper, conducted under the conditions of 200 times of this, DI
The N wear test was conducted under the conditions of a load of 1 kg and a running distance of 40 m. Tan δ was determined using a viscoelastic spectrometer (YES-F) manufactured by Wakagi Seisakusho, giving a sinusoidal elongation-compressive strain of 5% initial strain and 1% dynamic strain. Note that the measurement is in the grain direction.

From the table above, when using VGCF, the amount of wear is considerably lower than when using conventional PAN-based carbon fiber, and among VCCF, graphitized products are even better than fired products. . Regarding tan δ, when VCCF is used, it is higher than when using conventional PAN-based carbon fiber, especially graphitized products, which are advantageous in terms of vibration-proofing and sound-proofing effects.

Furthermore, as for the running test results, the system using VCCF has a lower canvas wear residual rate and a longer durability life in the load test.

(Effect of the invention) The invention of claim (1) has V in the reinforcing fabric as described above.
Since it is impregnated with GCF, the wear resistance of the teeth improves, and the strength increases due to the reduction in tooth wear. Also, V
Rubber containing GCF has a large tan δ, has vibration and soundproofing effects, stabilizes meshing, and extends belt life.

In the invention of claim (2), the above effect is further enhanced by the reinforcing adhesive rubber layer laminated on the side of the reinforcing canvas layer that comes into contact with the pulley.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of a toothed belt, and FIG. 2 is an enlarged detailed view of section A in FIG. 1. 1...Toothed belt 3...Tooth rubber layer 4...Reinforcement adhesive rubber layer 6...Vapour-grown carbon fiber (VGCF) 7...・
... Reinforcement canvas layer 1 ... Toothed belt 3 ... Tooth rubber layer 4 ... Reinforcement adhesive rubber layer 6 ... Vapor-grown carbon fiber 7... Reinforced canvas layer (VG CF) Fig. 1 Fig. 2

Claims (2)

[Claims] (1) In a toothed belt in which the surface of the toothed rubber layer is covered with a reinforcing canvas layer, the reinforcing canvas layer covering the toothed rubber layer is impregnated with rubber in which vapor-grown carbon fibers are mixed. A toothed belt characterized by: (2) The toothed belt according to claim (1), wherein a reinforcing adhesive rubber layer containing vapor-grown carbon fibers is laminated on the side of the reinforcing canvas layer that contacts the pulley.