JP2002068439A - Antistatic carrier belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide an antistatic carrier belt excellent in conductivity and adhesive strength without staining a carrier article. SOLUTION: The carrier belt made of a core body 3 made of a textile material, a cover rubber layer 2 to form a carrier surface and an adhesive rubber layer 4 between the core body 3 and the cover rubber layer 2 and using color rubber as the cover rubber layer is constituted by blending a 10-40 pts.wt. of carbon black having conductivity of a particle diameter of 20-40 nm to rubber 100 pts.wt. in the adhesive rubber layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyor belt used for manufacturing cardboard, etc., and more particularly to an antistatic conveyor belt capable of preventing static electricity generated during traveling by imparting conductivity.

[0002]

2. Description of the Related Art As shown in FIG. 2, a belt for transporting articles generally has a belt 1 stretched between two pulleys 10 at least one of which is a driving pulley provided at both ends. The table 11 is arranged and configured. In such a transport belt, the friction between the belt 1 and the pulley 10 during transport or between the table 11 and the belt 1 disposed on the back surface of the belt during travel. Can generate static electricity. For example, such a conveyor belt is also used in the process of manufacturing cardboard, but the static electricity generated as described above leads to a malfunction of a computer that controls the machine, or draws rubber such as paper powder to the surface of the cardboard, and There is a problem that dust adheres and hinders printing on cardboard.

In order to solve these problems, it has been considered variously to make the belt itself conductive so that static electricity is not accumulated on the belt. For example, a non-conductive fibrous tensile member is made of carbon having conductivity. A powder such as black is adhered to form a core body (see Japanese Utility Model Publication No. 50-18032), or a highly conductive carbon black or the like is blended into the tooth side rubber of the toothed belt for conveyance (Japanese Patent Application Laid-Open No. -772
No. 44) has been proposed.

However, in the case of a belt used for conveying cardboard as described above, it is not preferable to mix carbon black in the cover rubber layer which is the conveying surface in order to prevent the cardboard from being stained with black. Usually, a color rubber other than black which does not contain carbon black is used. Since carbon black cannot be blended in the cover rubber layer as described above, it is difficult to impart conductivity. Of course, this does not mean that it is not possible to actually impart conductivity, but using a conductive agent other than carbon black is disadvantageous in terms of rubber properties, such as insufficient strength of the cover rubber, early abrasion, and generation of cracks. There are problems and problems that lead to increased costs.

In order to prevent carbon black from being contaminated by carbon black from the belt surface, a conductive thin film or resin not using carbon black is used (Japanese Patent Application Laid-Open Nos. 9-166183 and 3-277850).
Further, a tensile body and a conductive layer in which carbon black is mixed with a flexible rubber-like elastic substance are alternately polymerized and adhered to form a belt base, and the surface thereof is covered with a rubber-like elastic body coating layer. (Microfilm No. 53-13779) has been attempted.

[0006]

However, the above-mentioned conductive thin film not using carbon black is intended for an endless rubber belt without a core or a cover cloth, and the resin is intended for a flat belt made of resin. Layer, adhesive rubber layer,
It is completely different from the belt structure consisting of a core body, and the antistatic belt in which carbon black is mixed in the conductive layer of the belt base simply mixes carbon black. Not resolved.

In view of the above situation, the present invention pays particular attention to the adhesive rubber layer in the conveyor belt, and pursues an appropriate particle size and blending amount of the carbon black to find the carbon black, thereby contaminating the conveyed object. SUMMARY OF THE INVENTION It is an object of the present invention to provide an antistatic conveyance belt which conveys the belt without charge, and which has conductivity at a low cost.

[0008]

According to the present invention, in order to achieve the above object, a core body made of a fiber material and a cover rubber layer forming a conveying surface, and the core body and the cover rubber are provided. A conveyor belt comprising a color rubber as a cover rubber layer, wherein the particle diameter is 20 to 100 parts by weight of rubber in the adhesive rubber layer.
Conductive carbon black having a thickness of 50 nm
Approximately 40 parts by weight are blended to form an antistatic conveyance belt.

By blending carbon black having conductivity of the above-mentioned particle size into the adhesive rubber layer at a predetermined ratio, conductivity can be imparted to the belt. Even if static electricity is generated due to friction between the belts, the belt is not charged, troubles of machinery due to static electricity and the like can be prevented, and black stains can be prevented even when cardboard is transported.

[0010] In claim 2, it is more preferable that the conductive carbon black to be blended has a bulk specific gravity of 0.4 or less.

[0011]

According to the present invention, by mixing a predetermined ratio of carbon black having a required particle diameter into the adhesive rubber layer,
The performance required for the adhesive rubber layer includes an adhesive force with a core made of a fiber material. In addition, conductivity is imparted. When compounding carbon black, the use of carbon black having a small particle diameter in the above range can greatly improve the conductivity.However, when using carbon black having a large particle diameter beyond this, sufficient conductivity is obtained. I can't. Further, if a large amount of carbon black having a too small particle diameter is used, the adhesive force of the adhesive rubber layer becomes insufficient, so that 10 to 40 parts by weight is appropriate. By using carbon black having such specifications, it is possible to obtain an adhesive rubber layer having excellent adhesiveness as well as conductivity.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. The antistatic conveyor belt 1 of the present invention is shown in FIG.
As shown in the cross section, the uppermost cover rubber layer 2 which forms the conveying surface and the core body 3 which bears the tensile strength of the belt
And an adhesive rubber layer 4 disposed between the cover rubber layer 2 and the core body 3 and between the core bodies 3 and serving as an adhesive.

In FIG. 1, the heart 3 has three plies.
This number of layers can be changed as needed,
Usually, about 1 to 5 plies are used. The cover rubber layer 2 is made of a rubber that does not contain a large amount of carbon black, so that the conveyed material is not stained with carbon black. Color rubber.

The type of rubber is not particularly limited, and natural rubber (NR), styrene butadiene rubber (S
A simple rubber such as BR), acrylonitrile rubber (NBR), ethylene propylene rubber (EPR), butadiene rubber (BR), or a rubber obtained by blending these rubbers can be used. Further, compounding agents that are usually compounded with rubber, such as plasticizers, zinc oxide, silica, calcium carbonate, sulfur, and vulcanization accelerators are used. However, carbon black is less than 2 parts by weight, based on 100 parts by weight of rubber, even if it is blended for the purpose of preventing the above-mentioned dirt. In addition, pigments such as inorganic pigments and organic pigments are appropriately blended for coloring. It is also possible to use rubber which has been used. In addition, although it is a color rubber, it is not always necessary to mix a pigment for coloring, but rather, for the purpose of reducing stains due to the adhesion of carbon black to a conveyed product, the compounding amount of carbon black is It is important that the amount is less than the predetermined amount.

As the core 3, a rope or canvas made of a fiber material can be used. These materials include fibers such as polyamide, polyester, and cotton. For canvas, those obtained by plain weaving, twill weaving, and satin weaving of these fibers are used.

The adhesive rubber layer 4 is a characteristic part of the present invention, in which 10 to 40 parts by weight of conductive carbon black having a particle diameter of 20 to 50 nm is compounded with respect to 100 parts by weight of rubber. ing. Examples of the type of rubber used include a simple substance of natural rubber (NR), styrene butadiene rubber (SBR), acrylonitrile rubber (NBR), butadiene rubber (BR), and butyl rubber (IIR), or a blend thereof.

The types of conductive carbon black compounded in the rubber include SAF, ISAF, and carbon black.
IISAF-HS, HAF, HAF-HS, MAF, F
EF, a bulk specific gravity of 0.4 or less, and a particle size of 20
~ 50 nm, oil absorption of 1.0 cc / g or more, iodine adsorption of 40 mg / g or more, and DBP absorption of 1.0 cc / g or more are preferably used. In particular, the particle diameter is a numerical value relating to conductivity, and is an important numerical value for obtaining a belt having an antistatic function as in the present invention. The particle diameter of carbon black is generally not uniform, but is dispersed over a certain width.In the present invention, carbon black having a uniform particle diameter is required. Rather, it is sufficient that the numerical value serving as the center of dispersion is in the range of 20 to 50 nm.

If the particle size is less than 20 nm, the adhesion state of the adhesive rubber layer to the core 3 and the cover rubber layer 2 becomes poor, and
When the thickness exceeds 0 nm, adhesive strength can be obtained but conductivity is insufficient. Further, it is more preferable that the bulk specific gravity of carbon black is 0.4 or less, and if it exceeds 0.4, conductivity becomes insufficient. As described above, the carbon black is blended in an amount of 10 to 40 parts by weight with respect to 100 parts by weight of rubber, but if the amount of carbon black is less than 10 parts by weight with respect to 100 parts by weight of rubber, the adhesive rubber layer 4 When the content exceeds 40 parts by weight, the conductivity is sufficient, but the adhesiveness is deteriorated, and the adhesion between the cores 3 and between the core 3 and the cover rubber layer 2 is not sufficient. It is not preferable because it becomes sufficient. The types of carbon black that are not particularly suitable for use in the present invention are GPF, SRF-HS,
It is SRF-LM, and even if these carbon blacks are similarly blended in the adhesive rubber layer 4, sufficient conductivity cannot be obtained, so that the antistatic effect cannot be exhibited.

As described above, by adding a predetermined amount of carbon black to the adhesive rubber layer 4, a sufficient conductivity can be imparted to the transport belt, and a color rubber is used for the cover rubber of the transport surface. In the case of application, there is no black stain, it can prevent electrostatic charging of the belt, adversely affect surrounding control equipment, etc., and dust such as paper dust adheres to the belt and contaminates the conveyed goods It can be a belt without.

[0020]

EXAMPLES In order to confirm the effects of the present invention, the following tests were conducted for the following Examples and Comparative Examples.

Example 1 In Example 1, the following belt was used. The belt has a cover rubber layer (6.0 mm thick) on the surface as shown in FIG. 1 and a plain woven canvas (0.5 mm thick) made of five polyamide fibers and an adhesive rubber layer (0.9 mm thick). ) Are laminated and integrated. The rubber composition of the cover rubber layer is as shown in Table 1, and the rubber composition of the adhesive rubber layer is as shown in Table 2. Further, carbon black having a particle diameter of 30 nm was used as the carbon black to be mixed in the adhesive rubber layer.

(Example 2) As in Example 1, the belt of Example 2 has a belt structure as shown in FIG. 1, and the carbon black blended in the adhesive rubber layer has a particle diameter of 38 nm. All were the same as Example 1 except for using the same.

(Comparative Example 1) On the other hand, for comparison, the belt of Comparative Example 1 has a belt structure as shown in FIG. 1 as in Example 1, and carbon black particles mixed in the adhesive rubber layer. All the procedures were the same as in Example 1 except that the diameter was 15 nm.

Comparative Example 2 The belt of Comparative Example 2 has a belt structure as shown in FIG. 1 as in Example 1, and the particle diameter of the carbon black compounded in the adhesive rubber layer is 68 nm. Example 1 except for using
Same as.

The belt based on each of the above Examples and Comparative Examples was wound around a driving pulley of 100 mmφ and a driven pulley of 100 mmφ, and was run in an environment of a temperature of 31 ° C. and a humidity of 79% to form a STATILON S type The running belt voltage of the belt was measured using an electrostatic company. The distance between the belt and the measuring device is 50 mm. Further, a peeling test was performed to measure the adhesive strength. Table 3 shows the results of running band voltage and peel adhesion.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

As can be seen from the results in Table 3, in Comparative Example 1 in which the particle size of the carbon black compounded in the adhesive rubber layer is less than 20 nm, the running charge voltage is a sufficiently low value, but the adhesiveness is low. Insufficient, particle size 50nm
On the other hand, in Comparative Example 2 which exceeds, the traveling band voltage becomes large, and a sufficient antistatic function is not obtained. 20 ~
In Examples 1 and 2 of the present invention within the range of 50 nm, both the running band voltage and the peeling adhesive strength were good values.

[0030]

As described above, the present invention according to claim 1 comprises a core body made of a fiber material, a cover rubber layer forming a conveying surface, and an adhesive rubber layer between the core body and the cover rubber layer, In a transport belt using a color rubber as a cover rubber layer, the adhesive rubber layer is formed by blending 10 to 40 parts by weight of conductive carbon black having a particle diameter of 20 to 50 nm with respect to 100 parts by weight of rubber. By blending the conductive rubber black into the adhesive rubber layer, the conveyed material is not contaminated, and the belt can be provided with conductivity. Even if static electricity is generated due to friction between the belt and the belt, the belt will not be charged, and a remarkable effect can be achieved that can prevent malfunctions of machinery due to static electricity.

Further, if the carbon black having conductivity according to the second aspect of the present invention has a bulk specific gravity of 0.4 or less, there is an advantage that the above-mentioned effect can be exhibited without further shortage of conductivity.

[Brief description of the drawings]

FIG. 1 is a sectional view of an antistatic conveyance belt of the present invention.

FIG. 2 is a side view showing an example using the antistatic conveyance belt of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antistatic conveyance belt 2 Cover rubber layer 3 Core body 4 Adhesive rubber layer 10 Pulley 11 Table

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuya Fukaya, Inventor 4-1-1-21 Hamazoedori, Nagata-ku, Kobe Mitsusei Belt Co., Ltd. (72) Inventor Kazuyuki Kondo 4-1-1, Hamazoedori, Nagata-ku, Kobe-shi Mitsuhoshi Belt Co., Ltd. (72) Koichi Kitano, Inventor 4-1-1-21 Hamazoedori, Nagata-ku, Kobe Mitsuhoshi Belt Co., Ltd. (72) Inventor, Yoshimitsu Nakano Tarumachi, Kohoku-ku, Yokohama, Kanagawa Prefecture 3-7-16 Inside Tomoko Yokohama Plant, Ltd. (72) Inventor Tokuo Akita 7-17-23 Ikegami, Ota-ku, Tokyo Shinoda Corporation F-term (reference) 3F024 AA06 CA08 CB03 4J002 AC011 AC031 AC071 AC081 BB181 DA036 FD116 GM01

Claims (2)

[Claims] 1. A conveyor belt comprising a core made of a fiber material, a cover rubber layer forming a conveyance surface, and an adhesive rubber layer between the core and the cover rubber layer, wherein a color rubber is used as the cover rubber layer. 3. The antistatic transport belt according to claim 1, wherein 10 to 40 parts by weight of conductive carbon black having a particle diameter of 20 to 50 nm is mixed with 100 parts by weight of the rubber in the adhesive rubber layer. 2. The antistatic transport belt according to claim 1, wherein the conductive carbon black has a bulk specific gravity of 0.4 or less.