JPH09126280A - Tension member for belt, and belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve waterproof of the tension member for a glass fiber belt by bring a plural number of glass fibers into lines, dipping them into an adhesion processing fluid, whose principal component is a mixture of an initial condensation product of a resorcinol formalin and a hydro-nitrile rubber latex, pulling them up and giving a heat treatment. SOLUTION: A tension member 7 is made by bringing into lines eleven pieces of strands (first twist thread) 8 respectively given RFL treatment and giving final twist in the reverse direction of the first twist. In other words, the strand 8 is made by bringing into lines a fiber bundle made by focusing a plural number of non-alkali glass fibers 6 and giving a first twist. At the time of final twist, eleven pieces of these strands 8 are brought into line, clipped in an RFL fluid which is a mixture of an initial condensation product of a resorcinol and a formalin and hydro-nitrile rubber latex, pulling them up and giving a heat treatment, after which a glass cord is obtained by giving a final twist in the reverse direction of the first twist. A toothed belt is made by using the glass cord as the tension member 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt tension member used for various belts such as a toothed belt, a V-belt, a flat belt, and a speed belt, and the toothed belt using the belt tensioned member. Etc. regarding the belt.

[0002]

2. Description of the Related Art Transmission belts such as toothed belts are widely reinforced by using glass cords as tensile members in order to improve toughness or dimensional stability. For example, in the case of a transmission belt used for driving an OHC (overhead cam) of an automobile, it is usually ECG150-3.
/ 13 (Glass fiber bundles with a fiber diameter of 9 μm and 200 fibers are collected and twisted under to form a child lasso.
A cord obtained by gathering three strands and twisting them is adopted as a tensile member, and therefore, it has a twist and a twist.

As such glass cords, those treated with resorcin / formalin / rubber latex (hereinafter abbreviated as RFL) in order to improve the adhesion to the rubber of the belt body are generally used (for example, Japanese Patent Publication No. 3-422
90, JP-A-4-59640, and JP-A-4-59640.
50144). The RFL process is performed on the glass fiber bundle. That is, the glass fiber bundle is dipped in the RFL solution, pulled up, heated and dried, and then the above-mentioned twisting and twisting are performed.

[0004] Recently, as the temperature around the engine of an automobile rises, hydrogenated nitrile rubber, which is more excellent in heat resistance than conventional chloroprene rubber, has been used as a rubber for automobile belts. The hydrogenated nitrile rubber has a lower adhesion to the tensile body than other rubbers. Therefore, there is also a proposal of further applying rubber glue to the above-mentioned twisted yarn (see JP-A-2-4715 and JP-A-3-170534).

However, the RFL used for these glass cords has poor heat resistance. Therefore, it has also been proposed to treat with RFL using a hydrogenated nitrile rubber (H-NBR) latex having excellent heat resistance and low water absorption as a latex component (JP-A-63-270877).

[0006]

However, the glass cord obtained by treating with such a hydrogenated nitrile rubber latex type RFL, and then subjecting the lower twist and the upper twist to each other is such that the twist tends to return (easy to unwind), The code is not well-aligned. Therefore, although the belt using this as a tensile body can obtain expected performance in terms of heat resistance, when it is used under high temperature and high humidity such as in rainy weather, the tensile body deteriorates early and the belt There is a problem that the strength is remarkably lowered, and the bending fatigue resistance of the belt is also lowered, so that the belt is easily cut. That is, the object of the present invention is to improve the heat resistance and water resistance of the glass fiber tensile member for a belt, and further to improve the heat resistance and water resistance of the belt.

[0007]

The inventor of the present invention has begun to investigate the cause of the above-mentioned problems from early on, and the adhesion between the above-mentioned twisted yarns (3/0 fiber bundles) is low, and the water inside the tensile body is also reduced. It has been found that the adhesion is greatly reduced by the penetration of

That is, the glass fibers of the glass fiber bundle are adhered to each other by the above-mentioned H-NBR type RFL, and the glass fiber bundles forming the undertwist are also closely adhered to each other via the RFL of the surface. There is. However, the surface itself of the ply-twisted yarn has almost no adhesiveness, and therefore, even if several more ply-twisted yarns are aligned and ply-twisted, the twist is likely to return and the form of the cord is not stable. Moreover, since the surface of each ply-twisted yarn has minute irregularities due to twisting, the ply-twisted yarns do not completely adhere to each other, and when moisture enters the tensile body, this moisture causes the adhesion between the ply-twisted yarns. It means that the lower twisted yarns having a large degree of freedom are displaced from each other and damage each other. Hereinafter, means for solving the above problems will be specifically described.

First, the invention according to claim 1 is a belt tension member composed of a plurality of glass fibers, wherein the plurality of glass fibers are aligned and hydrogenated with an initial condensate of resorcin-formalin. By being immersed in an adhesive treatment liquid containing a mixture of nitrile rubber latex as a main component, pulled up, and heat-treated, it is adhered to each other by an adhesive containing the mixture as a main component impregnated between the glass fibers. , A belt tension member characterized by being twisted in one direction.

The invention according to claim 2 is a belt tension member which is also composed of a plurality of glass fibers, wherein a plurality of pretwisted glass fiber bundles are aligned and the initial condensation of resorcin-formalin is performed. And a hydrogenated nitrile rubber latex mixture are immersed in an adhesive treatment liquid containing the mixture as a main component, and the mixture is pulled up and heat-treated, so that the mixture containing the mixture impregnated between the glass fiber bundles as the main component It is characterized in that, in a bonded state, it is twisted in the opposite direction to the lower twist.

The invention according to claim 3 is characterized in that the surface of the tensile member for a belt according to claim 1 or 2 is covered with a film containing rubber as a main component. Is a tensile body.

The invention according to claim 4 is a belt characterized by comprising the belt tension member according to any one of claims 1 to 3.

The glass fiber used in each of the above inventions is not particularly limited, and generally called non-alkali glass fiber can be used.

The RFL of each of the first and second aspects of the invention is
An initial condensate of resorcin and formalin is mixed with hydrogenated nitrile rubber latex, but an additive such as a softening agent can be added if necessary.

In the invention according to claim 3, the rubber material forming the film is not particularly limited, but in consideration of the adhesiveness with the belt main body rubber, chlorinated rubber, polyvinyl chloride, Halogen-containing substances such as chloroprene rubber and chlorosulfonated polyethylene are preferred.
Further, in forming the above-mentioned film, the solvent for dissolving rubber or the like is not particularly limited, but aromatic hydrocarbons such as benzene, toluene, xylene, ethers, halogenated aliphatic hydrocarbons such as trichloroethylene, etc. Etc. are preferably used.

(Operation) In the invention according to claim 1, the belt tension member draws a plurality of glass fibers in parallel, and R
Since it is made by twisting in one direction after FL treatment, there is no problem of peeling between the undertwisted yarns in the first place, and when this is used as a tensile member for a transmission belt, the weakness of glass cord has been The water resistance to bending fatigue is improved. That is, even if the RFL latex is hydrogenated nitrile rubber, water resistance can be obtained. On the contrary, since the latex of the RFL is hydrogenated nitrile rubber, the tensile body has high heat resistance and the water absorption of the hydrogenated nitrile rubber latex is low, so that the moisture content between the glass fibers that are bound together is high. This prevents the belt from unraveling, which is advantageous for improving the above water bending fatigue resistance of the belt.

According to the second aspect of the invention, a plurality of ply-twisted yarns, each ply-twisted, are aligned and subjected to RFL treatment, and then ply-twisted in the opposite direction to the ply-twisted yarn is added. Even if the latex of RFL is hydrogenated nitrile rubber, the ply-twisted yarns are closely adhered to each other via the RFL, water is prevented from entering between the ply-twisted yarns, and the water resistance is increased. Moreover, the tensile member has low rigidity, and when it is used as a tensile member for a transmission belt, bending fatigue resistance is high. Then, since the latex of the RFL is hydrogenated nitrile rubber, like the invention according to claim 1,
It is advantageous for improving heat resistance and water bending fatigue resistance.

In the invention according to claim 3, since the rubber film is formed on the surface of the belt tension member, the adhesion between the tension member and the belt main body rubber is enhanced and the belt running stability is improved. , Water flexion fatigue resistance is dramatically improved.

Since the invention according to claim 4 is a belt using the tensile member for a belt according to any one of claims 1 to 3, the action of the invention according to each of the above claims The effect can be obtained.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Example 1 A belt 1 is shown in FIG. The belt 1 is a toothed belt (transmission belt), and includes a tensile body 2 provided in the circumferential direction of the belt, a back rubber 3 provided on one side (rear side) of the tensile body 2, and a back rubber 3. A tooth rubber 4 is provided on the side opposite to the rubber 3 at a predetermined pitch in the circumferential direction of the belt, and the tooth rubber 4 side is covered with a tooth cloth 5.

FIG. 2 shows the tensile body 2. This tensile body 2 is made by aligning 33 fiber bundles each of which is formed by bundling 200 alkali-free glass fibers (E glass having a diameter of 9 μm) 6 and using H-NBR (hydrogenated nitrile rubber) as latex. The glass cord is formed by immersing in an RFL liquid having the following composition used, pulling it up, heat-treating it at 250 ° C. for 1 minute, and then twisting it at a twisting frequency of 2.0 times / inch.

-H-NBR RFL formulation (weight ratio) -Resorcin 7.2 37% formalin 7.6 10% NaOH aqueous solution 7.0 H-NBR latex 401.7 (Zetpol 2020: manufactured by Zeon Corporation) Ionized water 465 The back rubber 3 and the tooth rubber 4 are formed of a rubber composition containing hydrogenated nitrile rubber as a main raw material. Further, in the above-mentioned tooth cloth 5, 6,6-nylon yarn is used for the yarn extending in the belt width direction, and industrial 6,6-nylon woolly processed yarn is used for the yarn extending in the belt longitudinal direction.

The above-mentioned toothed belt 1 is formed by the usual press-fitting method using each of the above-mentioned materials, and the tooth pitch is 8 mm.
It is a TS tooth type having 113 teeth and a belt width of 19 mm.

<Embodiment 2> As shown in FIG. 3, the tensile member 7 of this embodiment is the reverse of the undertwist by aligning 11 strands (undertwisted yarn) 8 each subjected to RFL treatment. It is twisted in the direction.

That is, the above-mentioned strands 8 are prepared by bundling three fiber bundles each of which is made by bundling 200 alkali-free glass fibers 6 (similar to those in Example 1), and twisting 2.0 times.
It is made by twisting at a twist of 1 inch. At the time of the upper twist, 11 strands 8 were aligned and immersed in the same RFL solution as in Example 1, pulled up and subjected to heat treatment at 250 ° C. for 1 minute, and then twisted in the opposite direction to the lower twist. A glass cord was obtained by performing twisting at 2.0 times / inch. Then, the toothed belt 1 similar to that in Example 1 was prepared by using the glass cord as the tensile body 7.

Example 3 The twisted glass cord of Example 1 was dipped in a 20% by weight solution of a rubber paste containing chlorosulfonated polyethylene as a main component and pulled up to 150
By drying for 1 minute in an atmosphere of ° C, a rubber film 9 was formed on the surface of the glass cord as shown in Fig. 4. Then, this was used as a belt tension member 10 to prepare a toothed belt 1 similar to that in Example 1.

Example 4 The same glass paste treatment as in Example 3 was applied to the glass cord after the overtwisting of Example 2 to form a rubber film on the surface thereof, which was used as a belt tension member. A toothed belt similar to that in Example 1 was prepared.

<Comparative Example 1> Three fiber bundles each containing 200 non-alkali glass fibers (E glass) having a diameter of 9 μm are aligned and immersed in the same RFL solution as in Example 1,
Number of twists 2.0 after heat treatment at 250 ° C for 1 minute
Twisted / inch and twisted into a lasso. This child rope 1
Collect one strand and twist it in the opposite direction to the above-mentioned twist, 2.0 times / in
A glass cord was created by twisting it on the ch. Then, using this as a belt tension member, a toothed belt similar to that of Example 1 was prepared.

<Comparative Example 2> A rubber coating is formed on the surface of the glass cord after the upper twist of Comparative Example 1 in the same manner as in Example 3, and this is used as a belt tension member, and the same tooth as in Example 1 is used. The attached belt 1 was created.

<Comparative Example 3> In Example 3, H-NB
Instead of R type RFL, the latex component is Vp-SBR
(Vinyl pyridine-styrene-butadiene latex)
A glass cord was prepared under the same conditions and method as in Example 3 except that the above Vp-SBR RFL was used, and the same toothed belt as in Example 1 was prepared using this as a belt tension member.

<Comparative Example 4> In Comparative Example 2, H-NB
Vp-SBR system R in the same manner as in Comparative Example 3 instead of R system RFL
A glass cord was prepared under the same conditions and method as in Comparative Example 2 except that FL was used, and this was used as a belt tension member to prepare a toothed belt similar to that in Example 1.

(Water Injection Bending Fatigue Test) A bending fatigue test was performed on each of the belts of the above Examples and Comparative Examples. That is, the toothed belt A is wound around four large pulleys 31 constituting the belt bending tester shown in FIG. 5 and four small pulleys 32 (diameter 30 mm) arranged between the adjacent large pulleys 31, 40 kgf on the toothed belt A with the weight 33
With the tension applied to the toothed belt A at a rate of 1 liter per hour, 55
The belt was run at a cutting speed of 00 rpm, and the number of times the belt was bent up to the cutting was examined.

(Bending test after heat aging) 150 test belts
It was kept in an oven at ℃ for 168 hours, and thereafter, this was put into a running tester having the same layout as in FIG. 5, and the belt strength maintenance ratio after bending and running 1 × 10 ⁸ times was examined. Water was not dropped in the running test. The test results are shown in Table 1 together with the results of the water-filled flex fatigue test.

[0034]

[Table 1]

As is clear from the test results shown in Table 1,
It was found that the use of the tensile body according to the present invention in a belt as in Examples 1 to 4 dramatically improves the water resistance of the belt as compared with Comparative Examples 1 and 2, and Comparative Example 3, As can be seen from the comparison with 4, heat resistance is maintained.

Example 1 and Example 2 are different in only the presence or absence of undertwisting before RFL treatment, and the relationship between Example 3 and Example 4 is also the same. Comparing each of these, the ply-twisted one has a larger number of flexing times before cutting, and the belt strength maintenance rate after heat aging running is also higher. Therefore, it is understood that it is more advantageous to improve the flex resistance of the belt by subjecting the glass fiber to the initial twist and then performing the RFL treatment.

The relationship between Example 1 and Example 3 is different only in the presence or absence of the rubber film on the surface of the tensile body, and the relationship between Example 2 and Example 4 is also the same. Comparing each of these, the one having a rubber coating has a greater number of flexing times before cutting. It is considered that this is because the rubber film stabilizes the adhesive force between the tensile body and the belt body rubber (back rubber and tooth rubber), and the water resistance of the belt is improved.

[0038]

According to the first aspect of the present invention, a plurality of glass fibers are aligned, treated with an RFL liquid using hydrogenated nitrile rubber latex, and unidirectionally twisted. Therefore, the heat resistance is good, and the adhesion of the fibers is not impaired even in the presence of water. As a result, when this is used as a tensile member for a belt, the water resistance flexing running performance is dramatically improved compared to the conventional one. Is improved.

According to the second aspect of the present invention, a plurality of the pretwisted glass fiber bundles are aligned and treated with the RFL liquid using hydrogenated nitrile rubber latex, and the upper twist is carried out in the direction opposite to the lower twist. Therefore, the rigidity of the tensile body can be softened, and the bending fatigue resistance is improved.

According to the third aspect of the invention, since the rubber film is provided on the surface of the tensile body, the adhesion between the tensile body and the rubber of the belt body is improved, and the running stability of the belt is improved.

According to the invention of claim 4, there is obtained a belt exhibiting the effects of the inventions of claims 1 to 3.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a toothed belt.

FIG. 2 is a partial cross-sectional perspective view showing the belt tension member of the first embodiment.

FIG. 3 is a partially sectional perspective view showing a belt tension member of Example 2.

FIG. 4 is a partially sectional perspective view showing a belt tension member of Example 3.

FIG. 5 is a schematic configuration diagram of a belt bending fatigue testing machine.

[Explanation of symbols]

 1 Toothed belt 2, 7 Tensile body 3 Back rubber 4 Tooth rubber 5 Tooth cloth 6 Glass fiber 8 Wool (bottom twisted yarn) 9 Rubber glue layer 31 Large pulley 32 Small pulley 33 Weight 34 Water A Test belt

Claims (4)

[Claims] 1. A belt tensile member comprising a plurality of glass fibers, wherein the plurality of glass fibers are aligned and mainly composed of a mixture of a resorcin-formalin precondensate and a hydrogenated nitrile rubber latex. It is twisted in one direction in a state where it is adhered to each other by an adhesive containing the above mixture impregnated between the glass fibers as a main component by being immersed in a bonding treatment liquid as a component, pulled up, and heat-treated. A belt tension member characterized in that 2. A belt tension member comprising a plurality of glass fibers, wherein a plurality of pretwisted glass fiber bundles are aligned and pre-condensate of resorcin-formalin and hydrogenated nitrile rubber latex. By being immersed in an adhesion treatment liquid whose main component is a mixture of
A tensile member for a belt, wherein the tensile member for a belt is obtained by twisting the glass fiber bundles in an opposite direction to the lower twist in a state where they are adhered to each other by an adhesive containing the above mixture as a main component. 3. A belt tension member according to claim 1, wherein the surface of the belt tension member is covered with a film containing rubber as a main component. 4. A belt comprising the belt tension member according to any one of claims 1 to 3.