JPS58109306A - Conveyer belt - Google Patents

Abstract

PURPOSE:To suppress generation of rust to a steel cord core body due to permeation of water into a core body layer of steel cords, by coating the core body layer of the steel cord with a layer of rubber composed material. CONSTITUTION:A core body layer 1 of steel cords consists of an adhesive rubber layer 3 embedded with the plural steel cords 2. This core body layer 1 is coated by intermediate rubber layers 4 consisting of rubber composed material, which suppresses generation of rust to the steel cord 2 due to permeation of water, further coated by cover ruber layer 5. In this way, rubber composed material layers suppressing the generation of rust to a core body of the steel cord are interposed as the intermediate rubber layers 4 between the layer 1 and layers 5. Thus the generation of rust to the steel cord 2 resulting from permeation of water into the layer 1 from the layer 5 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conveyor belt having a steel cord core layer, and more specifically, the present invention relates to a conveyor belt having a steel cord core layer. Therefore, the conveyor belt K11 can be stably used even in a humid place for a long period of time without deterioration of the steel cord core layer.

Conventionally, a conveyor belt is known in which a five-layer cover covers an adhesive rubber core layer in which a large number of steel cords are arranged in the longitudinal direction. Jin-type conveyor belts have excellent elongation, bending resistance, and impact resistance, but when used for long periods in humid places such as coal mines and tunnels,
Moisture that has penetrated from the belt surface into the core layer corrodes the steel cord, reducing the adhesive strength between the steel cord and the surrounding rubber layer, which may cause problems in the durability of the belt.

The present invention was made to improve the above situation, and
At least in conveyor belts made of upper and lower cutting rubber and steel cord core layers, suppressing the formation of rust on the steel cord core due to moisture permeation into the steel cord core layer will prevent the steel cord from corroding. This prevents the adhesive strength between the steel cord and the surrounding rubber layer from decreasing, and maintains the adhesive strength of the steel cord stably for a long time, making it more durable and suitable for use in hot places. It provides a good conveyor belt.

Hereinafter, one embodiment of the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a steel cord core layer, and this steel cord core layer 111tll also includes an adhesive rubber layer 3 in which several threaded cords 2 are embedded. Further, the steel cord core layer 1 is covered with the intermediate rubber layer 4 made of a rubber composition that suppresses the formation of rust on the steel cord 2 due to the permeation of 4#i moisture. Furthermore, 5 is a cover rubber layer that covers this intermediate rubber layer 4, and in this way, between the steel cord core layer 1 and the cover rubber layer 5 is a rubber composition layer that suppresses rust formation on the steel cord core. By interposing it as the intermediate rubber layer 4, rust formation on the steel cord 2 due to K is prevented when moisture permeates from the cover rubber layer 5 to the steel cord core layer 1.

In this case, the rubber composition forming the intermediate rubber layer 4 is
Butyl-based rubbers can be preferably used, and among these, brominated butyl rubbers and chlorinated butyl rubbers containing halogenated butyl rubbers can be preferably used. By using these butyl-based rubbers, moisture permeation can be suppressed. It is possible to suppress rust formation on the steel cord core.

These butyl rubbers can constitute 100% of the rubber component in the rubber composition forming the intermediate rubber layer 4, but
It can also be blended with natural fm1 synthetic rubber such as ■ or 81B. When blending butyl rubber such as halogenated butyl rubber with other rubber, the amount of butyl rubber is preferably 20 parts or more, especially 50 parts or more out of 100 parts of the total fm component. If the amount is less than 20 parts, moisture permeation may not be sufficiently suppressed. In addition, if a hygroscopic metal oxide such as magnesium oxide or calcium oxide and/or an electrolyte such as magnesium chloride is mixed with the rubber component, rust will occur on the steel cord core due to moisture permeation through the intermediate rubber layer 4. However, it is also possible to have five layers.

When forming a rubber composition that suppresses rust formation on the steel cord core due to moisture permeation by blending hygroscopic metal oxides such as magnesium oxide and calcium oxide or electrolytes such as magnesium chloride, the amount of hygroscopic metal oxides to be blended is The amount of electrolyte to be blended is preferably 0.1 to 20 parts per 100 parts of the mu component, from the viewpoint of the effect of suppressing complex formation and the physical properties of the product. In this case, the shim component shall contain at least 20 parts of butyl rubber based on 100 parts of the rubber component, and the shim component shall contain 20 parts or more of butyl rubber based on 100 parts of the rubber component. By adding 0.1 to 20 parts to the rubber composition, a rubber composition having an extremely excellent complex formation inhibiting effect can be obtained.

Note that the components of the adhesive rubber and cover rubber are not particularly limited, and commonly used known components may be used. Further, the steel cord used preferably has been surface-treated with zinc plating.

FIG. 2 shows another embodiment of the present invention, in which a steel cord core layer 1 is covered with a cover rubber layer 5. The rubber composition is made of a rubber composition that suppresses the formation of rust on the steel cord core, and this also makes it possible to effectively prevent the formation of rust on the steel cord.

It should be noted that the conveyor belt structure according to the present invention can of course be applied to the entire conveyor belt, but it is also highly effective when applied only to the grooves and edges during endless processing of the belt. Therefore, it can also be applied partially to desired locations in this way.

Therefore, the conveyor belt according to the present invention is based on the fact that the steel cord core layer is coated with a rubber composition layer that suppresses complex formation of the steel cord core due to moisture permeation.
When used for long periods in humid places such as coal mines or tunnels, the steel cord is less prone to rust and is highly durable.

EXAMPLES Hereinafter, the present invention will be explained in more detail by showing Examples and Comparative Examples.

[Examples 1 to 4. Comparative Example 1] A core layer 1 having a thickness of 4 cm and consisting of an adhesive layer 0, 5 layers, and 3 layers, in which a galvanized steel wire 2 with a diameter of 0.39 mm was embedded, was formed into a core layer 1 having a thickness of X cm (4≧X≧ 0) is coated with an intermediate barrier layer 4, which is further coated with a thickness of 4-X
covered with a cover shim layer 5 of thickness 12 as shown in FIG.
Samples of 60 widths and 210 lengths were prepared, and their steel wire adhesion strength and moisture permeability to the adhesive rubber layer were evaluated by the following test method.

The composition of each rubber layer is as shown in Table 1.

Table 1 [Test Method] Adhesive Strength Retention Rate The above sample was cut in the length direction at a distance of 40 mm from one end (1!-) of the total length. Peel off all the rubber except for 10cm from one end of this cut sample.
The exposed steel wire and the remaining part of the rubber are fixed in separate jigs, and the steel wire is pulled out from the rubber.

The pulling force required at this time is defined as the initial (before deterioration) adhesive strength.

Next, leave the sample of the residue cut in step 1 above in an atmosphere of constant temperature and humidity, take out the sample after a certain period of time, cut one end at 40 strips, and leave rubber up to 10 strips from the cut end. , the pull-out force is measured in the same manner as above, and this is taken as the adhesive strength after deterioration for a certain period of time. The remaining sample was further left in a constant temperature and humidity atmosphere, and after a certain period of time, it was taken out and the adhesive strength was measured in the same manner. Regarding the last sample, 10 pieces are cut off from one end, and 10 pieces are cut from there.
The pull-out force in the part (■) was measured.

The adhesive strength of the steel wire was evaluated using the ratio of the adhesive strength after deterioration measured as described above to the adhesive strength before deterioration as the adhesive strength retention rate.

In addition, the state of adhesion of rubber to the steel wire after drawing was examined and evaluated using the following criteria.

A: HN rate of rubber to wire 1oo~80%
B2 80-60%
C: 60-40%D
: 40~20
%E: 20~ OS
Note that the test conditions were 11t, 70°C, 95°C, and left in an RH atmosphere.

Moisture increase rate Accurately weigh 0.1 g of adhesive rubber cut out from the center of each sample (at a depth of 5.5 to 6.5 mm from the surface, indicated by 6 in Figure 3). , 150℃ using a moisture measuring device using the Karl Fischer amperometric titration method manufactured by Mitsubishi Chemical Corporation.
The increased moisture content was determined by measuring the amount of moisture generated by heating, and the moisture permeability to the adhesive layer was evaluated.

The above results are shown in Table 2.

[Examples 5 and 6, Comparative Example 2] The compositions of the cover gym layer and the five adhesive layers were the same as in Example 1, and samples were manufactured in which the intermediate rubber layer had the following composition,
A test similar to that described above was conducted.

Intermediate rubber layer composition Chlorinated butyl rubber 60 parts NR4Q Cargane black 50 Oil 15 Stearic acid 1 Anti-aging agent 1 Resin 5 Zinc white 5 Sulfur 1 Vulcanization accelerator 1.5 Organic crosslinking agent 1 The test conditions were 70°C x It was left in a 90% RH atmosphere.

The results are shown in Table 3.

31st! [Examples 7-10. Comparative Examples 3 and 4] The compositions of the force bar rubber layer and the five adhesive layers were the same as in Example 1, and the middle layer had a composition in which ~10 parts of magnesium oxide fθ was added to the cover gym layer of Example 1. It was manufactured and tested in the same way as above.

Note that the test conditions were to leave the sample in an atmosphere of 70° C. and 9096 RH.

The results are shown in Table 4.

[Example 11t12, Comparative Example 5] The composition of the cover rubber layer and the adhesive rubber layer was the same as in Example 1, and the intermediate rubber layer had the composition of the cover rubber layer of Example 1 with the addition of 5 parts of calcium oxide. It was manufactured and tested in the same way as above.

Note that the test conditions were to leave the sample in an atmosphere of 70° C. and 9096 RH.

The results are shown in Table 5.

Table 5 [Examples 13 to 16, Comparative Example 6] The compositions of the cover rubber layer and the adhesive rubber layer were the same as in Example 1, and 0 to 10 parts of magnesium chloride were added to the cover rubber layer. A sample was prepared in which one cover rubber layer was coated on each of the upper and lower sides of the adhesive rubber layer 2, and its steel wire adhesion strength and moisture permeability to the adhesive shim layer were evaluated in the same manner as in Example 1 ( However, test conditions: 50℃
×95% RH atmosphere). The results are shown in Table 6.

From the above results, it is recognized that the quantity of the present invention maintains the adhesion force of the steel wire well and has high durability.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted perspective view showing a conveyor belt according to one embodiment of the present invention, FIG. 2 is a partially omitted perspective view showing a conveyor belt according to another embodiment of the present invention, and FIG. 3 is an adhesive FIG. 3 is a cross-sectional view showing a sample used when measuring force retention and moisture increase rate. DESCRIPTION OF SYMBOLS 1... Steel cord core layer, 2... Steel cord, 4... Intermediate comb layer, 5... Cover rubber. Applicant: Pride's Tire Co., Ltd. 4R Agent Patent Attorney: Takashi Kojima Patent Attorney: Hajime Takahata

Claims (1)

[Claims] 1. A conveyor belt comprising at least upper and lower cover rubber and a steel cord core layer, which suppresses the formation of rust on the steel cord core due to moisture permeation into the steel cord core layer. 2. The conveyor belt according to claim 1, wherein the steel cord core layer is coated with a five composition layer that suppresses rust formation on the steel cord core layer. 3. The conveyor belt according to claim 2, wherein the rubber composition layer for suppressing rust formation on the steel cord core is interposed between the rubber and the steel cord core layer, with five intermediate layers. . 4. The conveyor belt according to claim 2 or 3, wherein the rubber composition layer that suppresses rust formation on the steel cord core contains butyl rubber. 5. The conveyor belt according to any one of claims 2 to 4, wherein the rubber composition layer that suppresses rust formation on the steel cord core contains a hygroscopic metal fluoride. 6. The conveyor belt according to any one of claims 2 to 5, wherein the rubber composition layer that suppresses rust formation on the steel cord core contains an electrolyte.