JPH08254249A - Treatment method for canvas for belt - Google Patents

Abstract

PURPOSE: To provide a treatment method for canvas for a belt which can improve mechanical characteristics and heat resistance of the canvas which are the weakest points of the belt using nitrile rubber hydride and bonding property of the canvas and nitrile rubber hydride, particularly, wear resistance and bending property of the canvas. CONSTITUTION: This is a treatment method of a canvas 14 for belt 11 made of nitrile rubber hydride mostly. Resorcinol-formalin-latex component containing nitrile rubber hydride is used as its latex component to cover the canvas 14 for belt. The amount of resorcinol-formalin-latex component adhered to the canvas 14 is approximately 10 to 50weight% for the weight of basic cloth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of treating a canvas which constitutes a part of a belt and is used to reinforce the belt.

[0002]

2. Description of the Related Art Conventionally, chloroprene rubber has been mainly used for belts such as toothed belts, V-belts and flat belts, but in recent years performances required for belts in various fields, such as mechanical characteristics, Heat resistance is increasing. Therefore, in place of the conventional chloroprene rubber belt, a material that can meet the above requirements, for example, hydrogenated nitrile rubber (H-NBR) has been put into practical use, and a belt canvas using this hydrogenated nitrile rubber. As before, rubber glue was used for the treatment.

However, the belt (11) having the canvas treated by the above conventional technique (see FIG. 1) is a belt even if the hydrogenated nitrile rubber (12) and the glass fiber cord (13) satisfy the new required performance. There is a problem that the sailcloth (14) does not satisfy the performance, and during use of the belt (11), the sailcloth (14) is cracked and the belt (11) is damaged.

That is, when the broken state of the belt (11) is analyzed for a toothed belt used as a timing belt in an automobile engine, first, the root portion of the canvas (14) covering the surface of the belt (11) is rooted. The most frequent weakness of the belt (11) is the most frequent weakness of the belt (11), which is caused by cracking from the (15), and then the tooth (16) of the belt (11) itself is lost and finally the belt (11) is damaged. Is considered to be in the canvas (14), and the V-belt and flat belt are also considered to be weak points in the canvas (14). That is, it is considered that the various properties (adhesiveness, wearability, bending fatigue property, mechanical properties such as the strength of the canvas) of the canvas (14) under the thermal environment are important.

[0005]

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is the most weak point of the belt using the hydrogenated nitrile rubber. It is an object of the present invention to provide a method for treating a belt canvas that can improve the mechanical properties of the canvas, the heat resistance, the adhesion between the canvas and the hydrogenated nitrile rubber, and especially the abrasion resistance and the flexibility of the canvas.

[0006]

[Means for Solving the Problems] In order to achieve the above object, a method for treating a belt canvas to obtain a canvas in which mechanical properties, heat resistance and adhesiveness are well-balanced is provided. I took technical measures such as.

That is, the present invention is a method for treating a canvas for a belt, which is mainly composed of hydrogenated nitrile rubber, wherein the latex component (hereinafter, appropriately referred to as L component) has hydrogenated nitrile rubber (hereinafter appropriately referred to as L component). (Abbreviated as H-NBR)
A resorcinol-formalin latex (hereinafter abbreviated as RFL) composition containing the above is used to coat a belt cloth, and the resorcinol-formalin
The amount of the latex composition deposited is about 1 with respect to the weight of the base fabric.
It is characterized in that it is 0 to 50% by weight.

As the L component, carboxylated NBR latex, chlorosulfonated polyethylene latex,
H-NBR latex, vinyl pyridine-styrene butadiene latex and the like are considered, among which H-N
The BR gave the best results as detailed below.

A base cloth is coated with an RFL composition having H-NBR in the L component. The amount of the composition adhered to the base fabric is 10 to 50% by weight, preferably 20 to 30% by weight, based on the weight of the base fabric. Here, the base cloth is RF
The L-treated product is a canvas, and the base fabric is a fabric before the RFL treatment.

The amount of adhesion is controlled by the ratio of the solid content of the RFL processing liquid and the gap amount of the squeezing roll during dip processing. Here, if the adhesion amount is less than 10% by weight, the adhesiveness between the canvas and the rubber or the abrasion resistance of the canvas decreases, and
On the other hand, if the content is more than 10% by weight, the mechanical properties and flexibility of the canvas will deteriorate.

[0011]

EXAMPLES Examples of the present invention will be shown below.

In the following description, numerical values are based on weight unless otherwise specified. (1) First, an RF solution is prepared, and an RFL composition is prepared with a latex containing H-NBR (hydrogenated nitrile rubber) as an L (latex) component.

(A) Preparation of RF Solution The R / F molar ratio is preferably 1: 1 to 5, more preferably 1: 1 to 2, and the RF solution was prepared at the ratios shown below.

Resorcin ... 17.3 g Formalin (35%) ... 13.2 g Water ... 340.5 g NaOH aqueous solution (10%) ... 3.7 g (total ... 374.7 g) (b) Preparation of RFL composition RF / L The solid content weight ratio is preferably 1: 4 to 20, more preferably 1: 5 to 10, and the RFL composition was adjusted so that the pH was 10 to 11 at the ratios shown below.

The RF liquid: 374.7 g * latex (L): 556.0 g Ammonia water (28%): 10.0 g Water: 282.6 g (total: 1223.2 g) As the * latex (L), Japan Zetpol from Zeon
2020 latex was used.

(C) Coating of the base cloth with the RFL composition Using the RFL composition, a base cloth made of nylon 6, nylon 66, etc. is squeezed during the dip treatment with the solid content ratio of the RFL processing liquid. Dip treatment is performed by controlling the amount of adhesion by the roll gap so as to be 30% by weight with respect to the weight of the base fabric, followed by drying at 110 ° C and heat treatment at 220 ° C. I got a canvas. (2) Evaluation test The following various tests were carried out using the canvas produced as described above or the belt produced by the following method using this canvas. The results of the examples are shown in (1) in the table and the figures showing the results. [Preparation of Belt] A timing belt was prepared by a known method using the following rubber compounds.

(Compounding ratio of hydrogenated nitrile rubber) * Hydrogenated nitrile rubber: 100 parts ZnO: 5.0 parts Carbon black: 40.0 parts Stearic acid: 1.0 parts Plasticizer: 10 parts Anti-aging agent: 2 .0 parts Sulfur ... 0.5 parts Accelerator (TT) ... 2.0 parts Accelerator (M) ... 0.5 parts (total ... 161.0 parts) Said * hydrogenated nitrile rubber, Zetpol of Zeon Corporation
2020 was used.

As comparative examples (2) to (4), L
An RFL composition was prepared using carboxylated NBR latex (2), chlorosulfonated polyethylene latex (3) and vinylpyridine-styrene butadiene latex (4) as the (latex) component. A compounding example is shown in Table 1.

Further, as another comparative example (5), a rubber mixture compounded in the following ratio was dissolved in 2.0 to 3.5 times its solvent, and then phenol resin was added to 20 parts of the rubber mixture.
About 35% was added and dissolved to prepare a rubber paste, which was prepared as a treating agent.

(Rubber mixture compounding ratio) * Hydrogenated nitrile rubber: 100 parts ZnO: 5.0 parts Carbon black: 40.0 parts Stearic acid: 1.0 parts Anti-aging agent: 2.0 parts Sulfur: 0. 5 parts Accelerator (TT) ... 2.0 parts Accelerator (CZ) ... 1.0 parts (total ... 151.5 parts) As * hydrogenated nitrile rubber, Zetp of Zeon Corporation
ol 2020 was used. Peeling test on adhesive strength between canvas and the rubber a. Peeling test at normal temperature A sample was prepared by pressing and vulcanizing canvas on hydrogenated nitrile rubber, and a peeling test between canvas and hydrogenated nitrile rubber was carried out at room temperature to measure the adhesive strength (test condition; tensile speed 50 mm /
min).

As is clear from the results shown in Table 2, the adhesive strength between the canvas according to this example and the hydrogenated nitrile rubber is much stronger than that using the conventional RFL composition. .

B. Peeling test for examining heat deterioration with lapse of time at 120 ° C. The width of the belt is adjusted to 19.1 mm and left in a gear oven at 120 ° C. for a predetermined period of time, and a peeling test for the bottom of the belt after heat deterioration is conducted. It performed at normal temperature and measured the adhesive strength. The results are shown in Fig. 2 (test conditions; pulling speed 50 mm /
min).

C. Peeling test for examining heat deterioration with time at 100 ° C in an oil atmosphere at regular intervals The width of the belt is adjusted to 19.1 mm, the belt is immersed in oil at about 100 ° C, and the canvas at the bottom of the belt is lapped at regular intervals. The peeling test was conducted at room temperature to measure the adhesive strength. The results are shown in Fig. 3.

D. Peeling test for examining heat deterioration with time at 100 ° C under boiling water atmosphere Aligning the width of the belt to 19.1 mm, immersing the belt in water at about 100 ° C, and removing the belt bottom of the belt at regular intervals. The peeling test was performed at room temperature to measure the adhesive strength. Fig. 4 shows the results.
Shown in

From FIG. 2 to FIG. 4, one of the above-mentioned adhesive strengths is obtained.
It is clear that the adhesive strength due to the heat deterioration at 20 ° C., the oil heat resistance deterioration at 100 ° C. and the boiling water heat deterioration at 100 ° C. is higher than the conventional one. That is,
It can be said that the canvas according to this example is suitable even under the condition of being exposed to oil or steam at high temperature.

Further, in any of the above graphs, the initial adhesive strength is particularly excellent. In this way, if the belt is excellent in adhesive strength during the initial operation (so-called running-in operation) when the belt and the member with which the belt engages are less familiar and unreasonable force is applied, deterioration at this time occurs. Is minimal, which has a particularly negative effect on the durability of the belt thereafter. Tensile test for examining the temporal deterioration of mechanical strength of canvas at a constant temperature of 120 ° C Aligning the width of the canvas to 25 mm, the canvas alone is press-vulcanized at 150 ° C for 20 minutes, and then placed in an oven at 120 ° C. After being left for each time, a tensile test in the expansion and contraction direction of the canvas after heat deterioration with time was performed at room temperature, the breaking strength was measured, and the rate of heat deterioration with time was calculated by comparison with the initial value (test condition; tensile speed 200 mm / Min).

From the results shown in FIG. 5, high temperature (120 ° C.)
It can be seen that the rate of thermal deterioration of mechanical strength below is also superior to that of conventional canvas. Abrasion resistance test a. Taber-type abrasion resistance test at room temperature Using a sample that has been subjected to press vulcanization treatment with a canvas alone at 150 ° C for 20 minutes, a Taber abrasion tester (model 5150)
A wear test was performed using The evaluation was based on the wear weight (loss weight) (test conditions; load 500 g, wear wheel H-18, rotation speed 4,000 rotations). The results are shown in Fig. 6.

B. Abrasion resistance test by changing thickness at constant time under 100 ° C. moist heat atmosphere A belt was laid over a pair of pulleys, and a running test was conducted in a tank in which water was boiled at the bottom. The evaluation was based on the degree of decrease in the thickness of the canvas at the tooth bottom of the belt after running. The result
As shown in FIG.

From the results shown in FIGS. 6 and 7, it can be seen that both the wear resistance at room temperature and the deterioration with time of the wear characteristics in a 100 ° C. moist heat atmosphere are superior to the belt using the conventional canvas. Endurance test by bending fatigue at 140 ° C Using a belt, using a DeMatcha bending tester (model; FT-202 [special]: manufactured by Ueshima Seisakusho) at an ambient temperature of 140 ° C, a bending test of canvas at the root of the belt I went. The evaluation was based on the number of times that cracks were formed on the canvas at the root portion of the belt over the entire cloth thickness. (Test condition: number of flexing 300 times per minute [one reciprocating motion is one time]; distance between gripping chucks of sample, maximum 75 mm, minimum 19 mm) The results are as shown in FIG. The durability of the belt using is obviously superior to the conventional belt. Running Test The following two types of running tests were performed using the timing belt. The running life was determined by the crack generation time over the entire thickness of the canvas at the root of the belt.

B. Heat-resistant running test at 110 ° C. The belt was stretched between a pair of pulleys at an ambient temperature of 110 ° C., and the crack life of the canvas at the root of the belt was evaluated by the crack generation time.

B. Root durability test at 80 ° C The belt was bridged between three pulleys at an ambient temperature of 80 ° C, and the crack life of the canvas at the root portion of the belt was evaluated by the crack generation time.

From the results shown in Table 2, it can be seen that the durability under high temperature operation is much better than that of the conventional belt.

Table 2 shows the test results of the above-mentioned a, b, and b.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

EFFECT OF THE INVENTION The belt using the canvas treated by the method for treating a belt canvas according to the present invention has the mechanical weakness of the canvas, which is the weakest point of the belt, as is clear from the test results shown in the table and the figures. It has the effect of being able to improve the properties, heat resistance, adhesiveness between the canvas and hydrogenated nitrile rubber, and especially the abrasion resistance and flexibility of the canvas.

[Brief description of drawings]

FIG. 1 is a perspective view showing a cross-sectional state of a toothed belt having a canvas treated by a method for treating a belt canvas according to the present invention.

FIG. 2 is a graph showing the results of a peel test on heat aging of the adhesive strength at 120 ° C.

FIG. 3 is a graph showing the results of a peeling test regarding heat aging of adhesive strength in an oil atmosphere at 100 ° C.

FIG. 4 is a graph showing the results of a peeling test regarding heat aging of adhesive strength in a boiling water atmosphere at 100 ° C.

FIG. 5 is a graph showing the results of a tensile test regarding heat aging of mechanical properties at 120 ° C.

FIG. 6 is a graph showing the results of tests on wear resistance at room temperature.

FIG. 7 is a graph showing the results of a durability test on wear resistance in a boiling water atmosphere at 100 ° C.

FIG. 8 is a graph showing the results of a durability test regarding bending fatigue at 140 ° C.

[Explanation of symbols]

 11 belt 14 canvas

Claims (2)

[Claims] 1. A method for treating a canvas for a belt mainly composed of hydrogenated nitrile rubber, which comprises resorcinol-formalin-containing latex hydrogenated nitrile rubber.
The belt composition is coated with a latex composition, and the amount of the resorcinol-formalin latex composition attached to the canvas is about 10 to 50% by weight based on the weight of the base fabric.
The method for treating a belt canvas according to claim 1. 2. The belt canvas according to claim 1, wherein the resorcin-formalin latex composition has an R / F molar ratio of 1: 1 to 5 and an RF / L solid content weight ratio of 1: 4-20. Processing method.