JPH0649804B2 - Transmission belt - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission belt, and more particularly to a power transmission belt having a low friction sliding surface.

[0002]

2. Description of the Related Art Noise and alignment of a transmission V-belt are related to the surface frictional resistance of the sliding surface of the belt.
By reducing the friction coefficient, it is possible to reduce noise and improve the alignment property. For this reason, it has been attempted, for example, to immerse the belt in a lubricant such as silicone oil prior to its use. However, according to this treatment, the use of the belt causes the adhesion of the belt surface. Since the silicone oil that is being scattered quickly spreads, the effect of reducing the friction coefficient of the belt sliding surface is
It disappears quickly and is not maintained for a long time.

On the other hand, since silicone oil has poor compatibility with rubber, the amount that can be directly kneaded with unvulcanized rubber is generally limited. For 100 parts by weight of rubber, 3 parts by weight or more are kneaded. Then, the bleeding on the rubber surface is remarkable, and the belt surface becomes sticky, and the function and product value of the belt are deteriorated. Further, it is not easy to directly knead silicone oil, which has poor compatibility with rubber, directly into the rubber, and as the compounding amount into the rubber increases, for example, in the case of kneading by the most common roll, the rubber is rolled. The roll operability, such as slipping on the roll or coming off the roll, deteriorates remarkably and cannot be uniformly dispersed in the rubber. As a result, the power transmission belt obtained from such an unvulcanized rubber composition lacks quality stability, and due to the intense bleeding of silicone oil, the effect of reducing the friction coefficient of the belt sliding surface is short-term. Disappears in the meantime.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned various problems, in which a lubricating agent made of silicone oil, which originally has poor compatibility with rubber, is porous. Adsorbed by the particles and evenly dispersed in the rubber, the lubrication agent bleeds onto the belt surface at a small speed that is substantially constant over a long period of time, and thus the belt surface is extended over a long period of time. Therefore, an object of the present invention is to provide a transmission belt having a substantially constant small friction coefficient, that is, a transmission belt having a low friction sliding surface.

[0005]

A transmission belt having a low-friction sliding surface according to the present invention has 100 parts by weight of rubber,
It is characterized in that 1 to 10 parts by weight of a lubricating agent made of silicone oil is adsorbed on the porous particles and is made of a vulcanized rubber of a rubber composition blended with the rubber. In the power transmission belt according to the present invention, the slipping agent means a compound which migrates to the belt surface due to poor compatibility with the rubber constituting the belt, reduces its frictional resistance, and makes the surface slippery. However, in the present invention, silicone oil is used as such a lubricant. Such a slipping agent is mixed with rubber by adsorbing it on the porous particles as a solution dissolved in an appropriate organic solvent or as an aqueous emulsion.

[0006] In the rubber industry, it is common practice to blend mineral oil into rubber as a process oil or a softening agent. However, process oils and softeners are essentially
It has good compatibility with rubber and is evenly dispersed in rubber.
It is used to soften the rubber and improve its processability and should not migrate to the rubber surface. On the other hand, when added to the rubber, the lubricant used in the present invention deteriorates the processability such as roll operability and easily migrates to the rubber surface.

According to the present invention, a slipping agent having a poor compatibility with rubber is adsorbed on the porous particles, so that the workability in kneading with rubber is not deteriorated and, on the other hand, it is applied to a transmission belt. After the vulcanization and molding, the transfer to the belt surface is controlled and, so to speak, is gradually released. Therefore, the lubricating agent made of silicone oil according to the present invention has a different purpose and function from the process oil and the softening agent, and should be distinguished from these.

In the present invention, the porous particles for adsorbing the above-mentioned lubricating agent have an average particle size of 1
Inorganic porous particles in the range of μm to 30 μm, preferably 10 μm to 25 μm are preferably used. Specific preferred examples of such inorganic porous particles include activated carbon, diatomaceous earth, and synthetic hydrated calcium silicate. In the present invention, in particular, activated carbon having an average particle size of 1 to 100 mμ and an average particle size of 1
Diatomaceous earth having a particle size of 0 to 30 μm and synthetic hydrated calcium silicate having an average particle size of 1 to 5 μm are preferably used.

In order to adsorb the lubricating agent made of silicone oil to such porous particles, they may be mixed by a usual method, for example, a method using a closed blender. The amount of the lubricating agent adsorbed to the porous particles depends on the types of the porous particles and the lubricating agent used, but is usually 100 to 1000 parts by weight, preferably 200 to 100 parts by weight of the porous particles. It is 500 parts by weight.

In order to knead the porous particles having the lubricant adsorbed therein to the unvulcanized rubber, conventional kneading means such as a kneading roll, a Banbury mixer, an intermixer or a spar mixer may be used. You can As the rubber, natural rubber, styrene-butadiene rubber, butadiene rubber, chloroprene rubber, ethylene-propylene-
Diene rubber, butyl rubber, isobutylene rubber, nitrile rubber, chlorosulfonated polyethylene rubber, polysulfide rubber, silicone rubber, urethane rubber, acrylic rubber and the like are used.

The amount of the lubricant added to the unvulcanized rubber may range from 1 to 10 parts by weight, preferably 2 to 8 parts by weight, particularly preferably 100 parts by weight of the unvulcanized rubber. Is 3 to 6 parts by weight. When the amount of the slipping agent is too small, the surface of the resulting vulcanized rubber transmission belt is insufficiently lubricated, and there is no effect in reducing the surface frictional resistance. The reason is that a lubricant having poor compatibility with rubber is excessively bleeding on the belt surface, which is not preferable.

In the present invention, the unvulcanized rubber composition may contain a vulcanizing agent, a vulcanization accelerator, an antiaging agent, a reinforcing agent, a filler, a lubricant and the like, which are usually blended with the rubber. . The unvulcanized rubber may be compounded with the unvulcanized rubber in combination with the unvulcanized rubber of the porous particles having the slipping agent adsorbed thereon, and the unvulcanized rubber may be previously compounded with the unvulcanized rubber. After blending the reinforcing agent, the filler, and the like, the porous particles having the slipping agent adsorbed thereon may be kneaded.

The transmission belt according to the present invention can be obtained by vulcanizing and molding such an unvulcanized rubber composition according to a conventional method.

[0014]

EFFECTS OF THE INVENTION In the power transmission belt according to the present invention, the lubricating agent made of silicone oil, which is originally poor in compatibility with rubber, is adsorbed on the porous particles, and the particles are uniformly dispersed in the rubber. It is obtained by vulcanizing and molding a vulcanized rubber. Therefore, in the transmission belt made of such a vulcanized rubber, the bleeding of the lubricant on the surface thereof is performed at a substantially constant small speed over a long period of time,
As a result, the surface of the power transmission belt has a small, substantially constant coefficient of friction over time.

Therefore, such a transmission belt suppresses noise during use and improves alignment.
Also, from the viewpoint of its production, generally, liquid chemicals such as silicone oil having poor compatibility with rubber are difficult to directly knead with rubber, but according to the present invention, porous particles Since it is adsorbed on, the kneading can be easily carried out by an ordinary method and a large amount can be blended.

[0016]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. In the following, "part" means "part by weight".

Example A synthetic hydrated calcium silicate (Jo
10 parts of Micro-Cel manufactured by hn Manville was mixed with 30 parts of silicon oil (KM722 manufactured by Toshiba Silicon Co., Ltd.) to obtain a slightly moist powder. Separately, 500 parts of neoprene GRT (manufactured by Showa Neoprene Co., Ltd.), 5 parts of stearic acid,
20 parts of magnesia, 25 parts of Zinc Hua No. 3, 5 parts of octylated diphenylamine and 250 parts of carbon FEF were kneaded with a roll, the powder obtained above was added to this kneaded rubber, and the kneaded with a roll to obtain an unvulcanized rubber composition. I got a thing.

This unvulcanized rubber composition was cut to a predetermined size, mounted on a Williams abrasion test mold, and vulcanized at a temperature of 148 ° C. for 3 minutes to obtain a vulcanized rubber test piece. The test piece was abraded with a Williams abrasion tester at a load of 2.6 kg, the polished surface was replaced with an iron piece, and the surface abrasion resistance was measured at a load of 4.1 kg. FIG. 1 shows the relationship between the rotation speed of the polished surface and the frictional resistance of the test piece. As a comparative example, 500 parts of the above-mentioned kneaded rubber and 30 parts of silicon oil were directly kneaded by a roll, and similarly, a vulcanized rubber test piece was obtained. However, the kneading was extremely difficult, and there were inconveniences such as the rubber coming off the roll, and the time required was 1.5 times as long as the above. Also for this test piece, after vulcanization in the same manner as above, the relationship between the rotation speed of the polishing surface and the friction resistance of the test piece is shown in FIG.

As is clear from the results shown in the figure, according to the present invention, the surface of the vulcanized rubber has a substantially constant surface friction resistance which is small over a long period of time. On the other hand, in the vulcanized rubber according to the comparative example, silicone oil was bleeding on the surface, and the surface frictional resistance increased rapidly.

[0020]

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between a polishing surface rotation speed and a surface friction resistance of a vulcanized rubber containing a lubricant made of silicon according to the present invention by a Williams abrasion tester together with a comparative example.

Claims (3)

[Claims] 1. A rubber composition comprising a vulcanized rubber having a rubber composition in which 1 to 10 parts by weight of a lubricating agent made of silicone oil is adsorbed on porous particles with respect to 100 parts by weight of rubber, and the surface is A transmission belt having a low friction sliding surface, characterized in that the lubricant is bleeded at a substantially constant small speed. 2. A transmission belt having a low friction sliding surface according to claim 1, wherein 100 to 1000 parts by weight of a lubricating agent is adsorbed on 100 parts by weight of the porous particles. . 3. The transmission belt according to claim 1, wherein the porous particles are activated carbon, diatomaceous earth or synthetic hydrated calcium silicate.