JPH07208555A - Fiber-reinforced rubber product - Google Patents

Abstract

PURPOSE:To improve the abrasion resistance of a reinforced body and the antiflexural fatigue performance of a rubber product, and improve the close adhesiveness of the reinforced body with the rubber layer by closely attaching a cord and a tube through heating, when the linear reinforced body embedded into a rubber product body is formed by inserting the cord into the tube. CONSTITUTION:Having the fiber-reinforced rubber product which is constituted so that the linear reinforcing bodies 5 are embedded in the product body of a rubber product, as objective product, the cord 6 consisting of the fiber bundles 6a as reinforcing body 5 is used by inserting it into the hollow part 7a of a tube 7 made of resin. In this case, the cord 6 and the tube 7 are closely attached through heating. Accordingly, the application of tension to the cord 6 through the tube 7 is prevented, and the tension distribution is made uniform, and the antiflexural fatigue performance of the fiber-reinforced rubber product is improved. Further, since the cord 6 is covered by the tube, the cord 6 is protected by the tube 7, and the abrasion of a strongly attached part in the early stage is prevented, even if the cord 6 has the locally strongly attached part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of fiber reinforced rubber products, and more particularly to measures for strengthening a linear fiber reinforced body embedded in a product body and measures for conforming to a rubber layer.

[0002]

2. Description of the Related Art Conventionally, rubber products such as belts, tires and hoses are required to have characteristics such as high strength, high elastic modulus and high dimensional stability. A reinforcing body such as a reinforcing cord made of a fiber bundle or a cloth-like material is embedded in the product body made of the product.

However, in a fiber reinforced rubber product in which the reinforcing body is composed of a reinforcing cord made of a fiber bundle, there is a portion where the filaments strongly contact each other at a deep angle inside the cord. There is a problem that it is likely to wear early.

Further, in the fiber reinforced rubber product using this cord, since the filaments constituting the cord are adhered and fixed to each other, uneven tension sharing occurs in the filament, causing breakage or reduction in strength and bending resistance. There is also the problem that fatigue becomes worse.

Therefore, as a measure for improving the above-mentioned problems such as abrasion resistance and bending fatigue resistance, it has been proposed to attach a wax-based oil agent which imparts smoothness to the fiber surface (Japanese Patent Application Laid-Open No. Hei 10 (1999) -242945). No. 2-210072, Japanese Patent Laid-Open No. 3-202
872, JP-A-3-873, and JP-A-3-873.
167376).

[0006]

However, in the fiber-reinforced rubber product of the above-mentioned proposal example, the use of an oil agent reduces the friction coefficient between filaments to solve the problems such as abrasion resistance and bending fatigue resistance. Although you can
This time, there is a problem that the adhesiveness to the rubber layer (product body) is hindered by the oil agent. Further, in the fiber reinforced rubber product using this oil agent, when the reinforcing agent is subjected to an adhesive treatment by RFL (resorcin-formalin-rubber latex) or the like, the oil agent adhered at the corner is sufficiently detached during the treatment process. It becomes impossible to exert a smooth sliding effect.

The present invention has been made in view of the above points, and an object thereof is to replace a cord made of a fiber bundle as a linear reinforcing member with an oil agent and replace the cord with a special material. By adopting the one covered with a material, in addition to improving the wear resistance of the reinforcement and the bending fatigue resistance of the fiber reinforced rubber product, the adhesion of the reinforcement to the rubber layer (product body) is also improved. There is something to do.

[0008]

In order to achieve the above object, the present invention is directed to a fiber reinforced rubber product in which a linear reinforcing body is embedded in a rubber product body. Was taken.

That is, the first solving means of the present invention employs a cord made of a fiber bundle inserted into the hollow portion of a resin tube as the reinforcing body. At this time, the cord and the tube are heated and brought into close contact with each other.

A second solving means of the present invention is characterized in that, in the first solving means, a lubricant is impregnated between the filaments constituting the fiber bundle of the cord.

The fiber-reinforced rubber products to which the present invention is applied include, for example, toothed belts, V-belts, flat belts and V-belts.
Examples of the belt include, but are not limited to, a transmission belt such as a ribbed belt, a conveyor belt, and tires and hoses other than the belt.

The rubber material constituting the rubber product body in the present invention is not particularly limited,
NR (natural rubber) and SBR commonly used for rubber products
(Styrene-butadiene rubber), NBR (nitrile rubber), H-NBR (hydrogenated nitrile rubber), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), ethylene propylene copolymer (EPM),
Ethylene propylene diene copolymer (EPDM), polybutadiene rubber (BR), polyisoprene rubber (I
R), fluororubber (FKR) and the like.

As the fiber material of the cord made of the fiber bundle which constitutes the linear reinforcing member in the present invention, for example, inorganic fibers, organic fibers and metal fibers are used.
It may be any spun yarn composed of long fibers and short fibers or a mixed yarn thereof. Examples of the cord structure include, but are not limited to, single twist, ply twist, rung twist, core yarn, and braid. Further, the total number of denier cords, the number of monofilament denier numbers, etc. may be appropriately selected according to the required performance of the fiber reinforced rubber product.

As the resin material of the resin tube in the present invention, nylon 6, nylon 6.6, nylon 6.
However, it is not limited to these. However, in order to heat the tube and bring it into close contact with the cord, it is necessary to select, as the resin species forming the tube, a resin whose softening temperature does not affect the cord. Further, the wall thickness and diameter of this tube may be appropriately selected according to the required performance of the fiber reinforced rubber product.

In the present invention, the lubricant to be impregnated between the filaments constituting the fiber bundle of the cord is, for example, silicone oil or the like which can obtain the lubricity between the filaments.

The reinforcing body formed by inserting the tube into the hollow portion of the cord is made of, for example, an epoxy resin, an isocyanate compound, an ethyleneurea compound and RFL before being embedded in the rubber layer as the product body. Adhesive treatment and stretching treatment are performed by a combination of adhesives.
As the adhesive treatment method, the dipping method is preferable because it is necessary to uniformly attach the adhesive to the reinforcing body.

[0017]

With the above structure, according to the first solution of the present invention, the cord made of fiber bundles is inserted into the hollow portion of the resin tube in the linear reinforcing member embedded in the rubber product body. Since the cord and the tube are heated and brought into close contact with each other, the tension is applied to the cord through the tube and is not directly applied to the cord. It is less likely to decrease, and the bending fatigue resistance of the fiber reinforced rubber product is improved.

Further, since the cord is covered with the tube, even if the cord has a locally strong adhesion portion between filaments, the cord is protected by the tube and the strong adhesion portion is not prematurely worn. .

Furthermore, by using an easily adhering tube such as nylon for a fiber having poor adhesiveness such as aramid fiber, the adhesiveness between the rubber layer and the reinforcing body constituting the product body is improved, Flexural fatigue resistance of fiber reinforced rubber products is significantly improved.

In the second solution of the present invention, the lubrication agent impregnated between the filaments constituting the fiber bundle of the cord and enclosed in the hollow portion of the tube further improves the lubricity between the filaments, and Flex fatigue and wear resistance are further improved.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a toothed belt A as a fiber reinforced rubber product according to an embodiment of the present invention. The toothed belt A is
The extension rubber layer 1 and a plurality (only two are shown in FIG. 3) integrally formed of rubber of the same material as the extension rubber layer 1 on one side (lower side in FIG. 3) of the extension rubber layer 1. Teeth 2,2
And a belt body 3 as a product body, and a tooth cloth 4 is integrally attached to the surface of the tooth portion 2 of the belt body 3. A plurality of linear reinforcing members 5 are embedded in the stretched rubber layer 1 of the belt main body 3 along the longitudinal direction of the belt. As shown in enlarged detail in FIGS. As a feature of the present invention, four fiber bundles 6a,
A cord 6 composed of 6a, ... Is inserted into a hollow portion 7a of a resin tube 7, and the cord 6 and the tube 7 are heated and brought into close contact with each other.

Next, the present embodiment 1, constructed as described above,
The flexural fatigue test of the toothed belt A according to No. 2 was performed under the following conditions and procedures together with the comparative example, and the results are shown in Table 1. The data in Table 1 is the belt strength maintenance rate (%).
Is.

[Construction of the toothed belt according to the first embodiment] As the cord 6 constituting the reinforcing member 5, Technora (trade name: Teijin Ltd.) 1500 de 4-strand braid cord (total denier: 6000 de) is used. I was there. As the tube 7, a general-purpose nylon 6.6 tube having an outer diameter of 1.5 mm and an inner diameter of 1.0 mm was used. The braided cord was inserted into the hollow portion of a nylon 6.6 tube, passed through an oven at 250 ° C. for 2 minutes, and heated and adhered to each other. The reinforcing body 5 was first dipped in an isocyanate compound adhesive and then in an RFL adhesive to form a second cord layer, and then heat-treated under tension. A plurality of the treated reinforcing bodies 5 are spirally arranged on the rubber-coated tooth portion 2,
After adhering a CR rubber sheet on it, pressurization and press-in vulcanization are carried out, so that the plurality of reinforcing bodies 5 are attached to the belt main body 3
A toothed belt A embedded in the stretched rubber layer 1 was obtained.

[Structure of Toothed Belt of Comparative Example] The same as in Example 1 except that the tube was not used, that is, the cord was used as a reinforcing member without inserting the cord into the hollow portion of the tube. Is.

[Structure of Toothed Belt of Second Embodiment] The same as the first embodiment except that general-purpose silicone oil is impregnated as a lubricant between the filaments constituting the fiber bundle 6a of the cord 6. is there.

[Procedure for Bending Fatigue Test] As shown in FIG. 4, four large pulleys 8, 8, ...
A belt bending tester provided with four small pulleys 9, 9, ... Arranged between 8 is prepared, and the toothed belt A is hung over the large and small pulleys 8 and 9 of the belt bending tester to weight 1.
At 0, the toothed belt A was run with a predetermined tension applied. The diameter of each small pulley 9 is 30 mm.
Is. Further, one cycle of the toothed belt A passes through each of the above four small pulleys 9, 9, ..., That is, the number of times the small pulley 9 bends the belt 4 times constitutes one cycle.

[0028]

[Table 1]

As is clear from the test data of Table 1, this Example 1 was superior to the comparative example in the belt strength maintenance rate.

Further, as can be seen from the test data of Example 2, by impregnating the filaments of the cord with the lubricant, the effect of the belt strength maintenance rate is further improved.

As described above, the strength of the belt 5 is higher in Examples 1 and 2 than in Comparative Example because the reinforcing member 5 is used.
This is because the cord 6 is inserted into the hollow portion 7a of the tube 7 and heated and brought into close contact therewith. That is, by protecting the cord 6 constituting the reinforcing body 5 with the tube 7, the wear resistance of the cord 6 can be improved, and the tension of the filament can be shared by eliminating the direct action of the tension on the cord 6. This is because the toothed belt A can be made uniform and the bending fatigue resistance of the toothed belt A can be made excellent. Further, the easily adhering nylon 6.6 tube can improve the adhesiveness between the reinforcing body 5 and the belt body 3 and greatly improve the bending fatigue resistance of the toothed belt A. Further, the lubricating effect of the silicone oil can further improve the bending fatigue resistance and abrasion resistance.

[0032]

As described above, according to the first aspect of the present invention, a cord made of a fiber bundle is used as a linear reinforcing member embedded in a rubber product main body and a cord made of a fiber bundle is hollow in a resin tube. Since the cord and the tube are heated and brought into close contact with each other, the cord can be protected by the tube to reduce the abrasion of the cord and improve the flex fatigue resistance of the fiber reinforced rubber product. Furthermore, the adhesion between the rubber layer and the reinforcing body can be improved by selecting the material of the tube.

According to the second aspect of the present invention, since a lubricant is impregnated between the filaments forming the fiber bundle of the cord, sufficient lubricity between the filaments can be obtained,
It is possible to further improve the bending fatigue resistance and wear resistance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a reinforcing body used in this example.

FIG. 2 is a perspective view of a reinforcing body used in this example.

FIG. 3 is a sectional view of a toothed belt.

FIG. 4 is a schematic configuration diagram of a belt bending tester.

[Explanation of symbols]

 3 Bell body (product body) 5 Reinforcement body 6 Cord 6a Fiber bundle 7 Tube 7a Hollow part A Toothed belt (fiber reinforced rubber product)

Claims (2)

[Claims] 1. A fiber reinforced rubber product in which a linear reinforcing member is embedded in a rubber product main body, wherein the reinforcing member has a cord made of a fiber bundle inserted into a hollow portion of a resin tube. A fiber reinforced rubber product, characterized in that the cord and the tube are adhered by heating. 2. The fiber-reinforced rubber product according to claim 1, wherein a lubricant is impregnated between the filaments forming the fiber bundle of the cord.