Conveyor belt

Abstract

To provide a conveyor belt exhibiting excellent anti-static property on a conveyance surface while being provided with an anti-static layer at a place separated from the conveyance surface.SOLUTION: This conveyor belt comprises: an anti-static layer containing conductive particles; and a cover layer having a conveyance surface and stuck on the anti-static layer. The cover layer contains a thermoplastic elastomer as a main component, and has a thickness of 300 μm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a conveyor belt.

Background Art

[0002] Conventionally, a conveyor system including a conveyor belt has been used. The conveyor system generally includes a conveyor belt and a pulley around which the conveyor belt is wound. Since the conveyor belt is bent around the pulley, it is preferably made of a material having excellent flexibility such as rubber or elastomer. On the other hand, such a conveyor belt has a problem that it is likely to be charged due to high electrical resistance values of rubber or the like in addition to friction with the pulley.

[0003] In order to solve such a problem, it is known to include a conductive agent such as carbon black together with rubber or elastomer. For example, the conveyor belt described in Patent Document 1 includes a core layer made of a fiber material, a cover layer having a conveying surface and made of a rubber material, and an adhesive rubber layer for adhering the cover rubber layer to the core layer, and the adhesive rubber layer contains carbon black. In the conveyor belt of Patent Document 1, the adhesive rubber layer serves as an antistatic layer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Like the conveyor belt of Patent Document 1, in order to exhibit its specific performance in the cover layer forming the conveying surface, an antistatic layer may be formed at a location away from the conveying surface, such as inside the belt or on the inner peripheral surface of the pulley side. In this way, when the antistatic layer is formed at a location away from the conveying surface, that is, when the antistatic layer is not the layer forming the conveying surface, the antistatic property of the conveying surface may become insufficient. And this can cause the adhesion of foreign substances to the conveyed object placed on the conveying surface, the generation of sparks due to the contact of the conveyed object to be placed with the conveying surface, and the like.

[0006] In view of the above circumstances, an object of the present invention is to provide a conveyor belt that has an antistatic layer at a location away from the conveying surface and is excellent in antistatic property of the conveying surface.

Means for Solving the Problems

[0007] The conveyor belt according to the present invention comprises an antistatic layer containing conductive particles and a cover layer laminated on the antistatic layer and having a conveying surface. The cover layer contains a thermoplastic elastomer as a main component and has a thickness of 300 μm or less.

[0008] Such a conveyor belt is excellent in antistatic property of the conveying surface because the cover layer contains a thermoplastic elastomer and its thickness is 300 μm or less.

[0009] Further, in the conveyor belt according to one aspect of the present invention, the resistance value of the conveying surface is 1.0×10 10 less than Ω.

[0010] According to the above aspect, since the resistance value of the conveying surface is less than 1.0×10 10 Ω, the conveying surface has sufficient antistatic property.

[0011] Further, in the conveyor belt according to one aspect of the present invention, the thickness of the antistatic layer is 1.5 times or more the thickness of the cover layer.

[0012] According to the above aspect, it becomes further excellent in antistatic property of the conveying surface.

[0013] Moreover, the conveyor belt according to one aspect of the present invention includes a core layer on which the antistatic layer is laminated. The core layer has a canvas containing conductive yarns.

[0014] According to the above aspect, since the canvas contains conductive yarns, the resistance value of the conveying surface can be further reduced, and the antistatic property on the conveying surface can be improved.

[0015] Moreover, the conveyor belt according to one aspect of the present invention The antistatic layer contains 3 mass% or more of carbon black, The color difference ΔE between the conveying surface and the antistatic layer, calculated by the following mathematical formula conforming to JIS Z8781-4:2013 * is 5 or more. ΔE * =[(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2 1 / 2

[0016] According to the above aspect, since the color difference ΔE between the antistatic layer that contains 3 mass% or more of carbon black and exhibits black and the conveying surface is 5 or more, the visibility for black conveyed objects in visual inspection can be enhanced. * is 5 or more, the visibility for black conveyed objects in visual inspection can be enhanced.

[0017] Moreover, the conveyor belt according to one aspect of the present invention has a content of the black component in the cover layer of 0.2 mass% or less.

[0018] According to the above aspect, since the content of the black component in the cover layer is 0.2 mass% or less, the visibility of black conveyed objects can be further improved.

[0019] Moreover, the conveyor belt according to one aspect of the present invention has a JIS A hardness of the conveying surface of 95 or more.​

[0020] According to the above aspect, in addition to the thickness of the cover layer being 300 μm or less, the JIS A hardness of the conveying surface is 95 or more, so that the occurrence of warping in the width direction of the conveyor belt is suppressed, and the conveying surface has excellent wear resistance.

Effect of the Invention

[0021] As described above, according to the present invention, it is possible to provide a conveyor belt that has excellent antistatic properties on the conveying surface while having an antistatic layer at a location away from the conveying surface.

Brief Description of the Drawings

[0022]

Figure 1

Mode for Carrying Out the Invention

[0023] Hereinafter, a conveyor belt according to an embodiment of the present invention will be described with reference to the drawings.

[0024] As shown in FIG. 1, the conveyor belt 1 includes a core layer 10, an antistatic layer 20 laminated on the core layer 10, and a cover layer 30 laminated on the antistatic layer 20. The conveyor belt 1 is used as an endless flat belt. Since the conveyor belt 1 is wound around a plurality of pulleys and used, it has an inner peripheral surface 11 that abuts against the pulleys and a conveying surface 31 that is the outer peripheral surface opposite to the inner peripheral surface 11.

[0025] The conveyor belt 1 may be for the purpose of conveying a black conveyed object. In a conveying method using such a conveyor belt 1, a visual inspection is performed on the conveyed object placed on the conveyor belt 1 (conveying surface 31). Therefore, it is preferable that the conveying surface 31 is designed to exhibit a color other than black.

[0026] The core layer 10 may have a canvas. The canvas is composed of conductive yarn containing carbon black as a conductive agent and non-conductive yarn not containing a conductive agent. The conductive yarn and the non-conductive yarn may be spun yarns or filament yarns. Examples of the resin constituting the conductive yarn and the non-conductive yarn include polyester-based resins, nylon-based resins, acrylic-based resins, aramid-based resins, and the like.

[0027] The core layer 10 may be a layer having an inner peripheral surface 11. The resistance value of the inner peripheral surface 11 is preferably less than 1.0×10 10 Ω, and more preferably 1.0×10 6 Ω or less. Thereby, the core layer 10 can exhibit an antistatic function particularly on the inner peripheral surface 11. Here, the resistance value can be measured by the measurement method specified in ISO21178, with the back surface (the surface that becomes the inner peripheral surface 11) of the laminate composed of the core layer 10 and the antistatic layer 20 as the measurement object.

[0028] The thickness of the core layer 10 is preferably 400 to 1000 μm. The thickness of the core layer 10 can be obtained by magnifying and observing the cross-section of the conveyor belt 1, measuring the thicknesses at 20 arbitrarily selected locations, and calculating the average value thereof.

[0029] The antistatic layer 20 may contain a thermoplastic elastomer as a main component and carbon black as conductive particles.

[0030] The thermoplastic elastomer of the antistatic layer 20 is preferably thermoplastic polyurethane, and more preferably polyester-based polyurethane. The polyester-based polyurethane may be a copolymer obtained by polymerizing a polyester polyol and a polyisocyanate in the presence of a cross-linking agent.

[0031] Examples of the polyester polyol include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene / butylene adipate diol, polyneopentyl / hexyl adipate diol, poly-3-methylpentane adipate diol, and polybutylene isophthalate diol.

[0032] Examples of the polyisocyanate include aromatic diisocyanates such as toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4'-methylenebis(phenylene isocyanate) (MDI), durylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate, benzidine diisocyanate, o-nitrobenzidine diisocyanate, 4,4'-diisocyanate dibenzyl; aliphatic diisocyanates such as methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,10-decamethylene diisocyanate; and alicyclic diisocyanates such as 1,4-cyclohexylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, hydrogenated MDI, and hydrogenated XDI.

[0033] The content of the thermoplastic elastomer in the antistatic layer 20 is preferably 85% by mass or more, more preferably 90% by mass or more and 95% by mass or less, based on the total mass of the antistatic layer 20.

[0034] The antistatic layer 20 may exhibit black color by containing carbon black which is a black component. The carbon black may be Ketjen black. Thereby, the antistatic property on the conveying surface 31 can be enhanced. Note that the antistatic layer 20 may contain channel black, furnace black, acetylene black, etc. as the carbon black. Further, the antistatic layer 20 may contain an ionic conductive agent such as sodium perchlorate as a conductive agent other than carbon black.

[0035] The content of the carbon black is preferably 1% by mass or more and 15% by mass or less, more preferably 3% by mass or more and 12% by mass or less, and particularly preferably 5% by mass or more and 10% by mass or less with respect to the total mass of the antistatic layer 20.

[0036] The surface of the antistatic layer 20 on the conveying surface 31 side preferably has a resistance value of 1.0×10 5 Ω or less, and more preferably 5.0×10 4 Ω or less. Thereby, the resistance value of the conveying surface 31 is likely to decrease, and the antistatic function can be exerted on the conveying surface 31. Note that the resistance value here is measured for the surface (the surface opposite to the back surface) of the laminate composed of the core layer 10 and the antistatic layer 20, and can be measured by the measuring method specified in ISO21178.

[0037] The thickness of the antistatic layer 20 is preferably 100 μm or more and 500 μm or less. The thickness of the antistatic layer 20 may be larger than the thickness of the cover layer 30. The thickness of the antistatic layer 20 is preferably 1.5 times or more, more preferably 2 times or more, and still more preferably 3 times or more with respect to the thickness of the cover layer 30. The thickness of the antistatic layer 20 can be obtained by observing the cross section of the conveyor belt 1 in an enlarged manner, measuring the thicknesses at 20 arbitrarily selected locations, and calculating the average value thereof.

[0038] The cover layer 30 may contain a thermoplastic elastomer as a main component and a pigment other than black. Preferably, the cover layer 30 does not substantially contain a black component such as carbon black. On the other hand, the cover layer 30 may contain a black component in an amount that does not make it black. For example, the cover layer 30 may exhibit a light gray color by containing 0.01% by mass or less of carbon black based on its total mass. As another aspect, the cover layer 30 preferably exhibits a green color, that is, preferably contains a green pigment.

[0039] As the pigment, a plurality of types of pigments may be used in combination. For example, by using a white-based pigment and a black-based pigment in combination, the cover layer 30 can be made to exhibit a gray color. Furthermore, by using pigments of other colors such as green and blue in combination and adjusting the blending ratio of each pigment, the cover layer 30 can be made to exhibit a desired color tone. The content (total mass) of the pigment in the cover layer 30 is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the cover layer 30 from the viewpoint of processability.

[0040] If the conveyor belt 1 does not include the cover layer 30 or if the cover layer 30 is colorless and transparent, when the antistatic layer 20 exhibits a black color, the conveying surface 31 will also exhibit the same black color as the antistatic layer 20. Therefore, when the purpose is to convey black objects (for example, black electronic components such as battery packs), it is difficult to visually recognize the black objects placed on the conveyor belt 1, which hinders visual inspection. In such a case, the conveying surface 31 is preferably designed to exhibit a color different from the black color of the antistatic layer 20. Specifically, the color difference ΔE * between the conveying surface 31 and the antistatic layer 21, calculated by the following mathematical formula in accordance with JIS Z8781-4:2013, * is preferably 5 or more, more preferably 12 or more. Also, with respect to the antistatic layer 20 containing the carbon black and having a lightness L * of less than 10, the lightness L *It is more preferable that the difference from [the other] is 5 or more. ΔE * =[(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2 1 / 2 Such a color difference can be realized by appropriately adjusting the type and content of the pigment contained in the cover layer 30 as described above. Of course, when the conveyed object is not black, or even when it is black and visual inspection is not required, the cover layer 30 may be a colorless and transparent cover layer 30 that does not contain a pigment.

[0041] Examples of the thermoplastic elastomer of the cover layer 30 include polyester-based polyurethane, polycarbonate-based polyurethane, and polyether-based polyurethane. The cover layer 30 may contain the same type of polyester-based polyurethane as the antistatic layer 20.

[0042] The content of the thermoplastic elastomer in the cover layer 30 is preferably 90% by mass or more, more preferably 95% by mass or more, based on the total mass of the cover layer 30. Also, the content may be 100% by mass.

[0043] The thickness of the cover layer 30 is preferably 30 μm or more. Thereby, the conveying surface 31 is likely to exhibit a hardness of a predetermined value or more, and the wear resistance is improved. Also, when embossing is applied to the conveying surface 31, the performance derived from the embossing is likely to be exhibited.

[0044] The thickness of the cover layer 30 is 300 μm or less, preferably 250 μm or less, and more preferably 200 μm or less. Thereby, the antistatic property on the conveying surface 31 is improved, and the warping of the belt is suppressed. The thickness of the cover layer 30 can be obtained by observing the cross section of the conveyor belt 1 in an enlarged manner, measuring the thicknesses at 20 arbitrarily selected locations, and calculating the average value thereof.​

[0045] The total thickness of the antistatic layer 20 and the cover layer 30 of the conveyor belt 1 may be smaller than the thickness of the core layer 10. The total thickness is preferably 90% or less, more preferably 80% or less, and even more preferably 70% or less of the thickness of the core layer 10. Thereby, the warp of the belt is suppressed.

[0046] The resistance value of the conveying surface 31 is preferably less than 1.0×10 10 Ω, more preferably 5.0×10 9 Ω or less, even more preferably 1.0×10 9 Ω or less, and particularly preferably 1.0×10 8 Ω or less. Thereby, the adhesion of foreign matters to the conveyed object placed on the conveying surface 31 is suppressed, and the generation of sparks due to the contact of the conveyed object with the conveying surface 31 is prevented. The resistance value of the conveying surface 31 can be measured by the measuring method specified in ISO21178.

[0047] The JIS A hardness of the conveying surface 31 is preferably 95 or more. Thereby, the abrasion resistance of the conveying surface 31 can be improved. The JIS A hardness of the conveying surface 31 is preferably 98 or less. Increasing the hardness of the conveying surface 31 causes warping in the width direction of the conveyor belt 1 as a flat belt (a state where both end portions in the width direction are lifted with respect to the central portion), but when the JIS A hardness is 98 or less, the occurrence of such warping can be suppressed. And the conveyor belt 1 with suppressed warping can contact the pulley appropriately, so that it can run at a stable speed and is easy to control the conveying amount.

[0048] In applications where the gripping force of the conveying surface 31 on the conveyed object is to be increased, the maximum static friction coefficient of the conveying surface 31 is preferably 0.6 or more. On the other hand, in applications where the conveyed object placed on the conveying surface 31 is stopped by a stopper or the like so that sliding friction occurs between the conveyed object and the conveying surface 31, the maximum static friction coefficient of the conveying surface 31 is preferably 0.6 or less. Note that the maximum static friction coefficient of the conveying surface 31 can be measured by the method specified in JIS K 6378-2:2012 (Light conveyor belt - Method for determining the coefficient of friction).

[0049] Next, a method for manufacturing the conveyor belt 1 will be described. The conveyor belt 1 can be manufactured by applying a resin composition for forming the cover layer 30, which is heated so as to be extrudable by a coater or the like, to an antistatic layer 20 whose surface (the surface on the conveying surface 31 side) is melted by heating. By such a manufacturing method, a boundary portion where the respective components are mixed is formed between the antistatic layer 20 and the cover layer 30. By forming such a boundary portion, peeling of the cover layer 30 from the antistatic layer 20 can be suppressed.

[0050] As described above, the embodiments have been shown as examples, but the conveyor belt according to the present invention is not limited to the configuration of the above embodiments. Also, the conveyor belt according to the present invention is not limited by the above-described effects. The conveyor belt according to the present invention can be variously modified without departing from the gist of the present invention.

[0051] This specification includes the following disclosures. (1) An antistatic layer containing conductive particles, and a cover layer laminated on the antistatic layer and having a conveying surface. The cover layer contains a thermoplastic elastomer as a main component and has a thickness of 300 μm or less, the conveyor belt. (2) The resistance value of the conveying surface is 1.0×10 10 Ω or less, the conveyor belt according to (1) above. (3) The conveyor belt according to (1) or (2) above, wherein the thickness of the antistatic layer is 1.5 times or more the thickness of the cover layer. (4) The conveyor belt includes a core layer on which the antistatic layer is laminated. The conveyor belt according to any one of (1) to (3) above, wherein the core layer has a canvas containing conductive yarns. (5) The antistatic layer contains 3% by mass or more of carbon black. The color difference ΔE between the conveying surface and the antistatic layer, calculated by the following formula in accordance with JIS Z8781-4:2013 * is 5 or more, and the conveyor belt according to any one of (1) to (4) above. ΔE * =[(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2 1 / 2 (6) The conveyor belt according to any one of (1) to (5) above, wherein the content of the black component in the cover layer is 0.2% by mass or less. (7) The conveyor belt according to any one of (1) to (6) above, wherein the JIS A hardness of the conveying surface is 95 or more.

Example

[0052] Next, examples will be shown for more specific description, but the present invention is not limited thereto.

[0053] (Example 1) Using the members shown in Table 1 below, a laminate was prepared in which an antistatic layer containing thermoplastic polyurethane and Ketjen black was laminated on one side of a canvas (thickness of about 700 μm) containing conductive yarns as a core layer. Next, the surface of the antistatic layer was heated to melt the thermoplastic polyurethane, and a resin composition containing the thermoplastic polyurethane was applied using a coater to form a cover layer with a thickness of 50 μm.

[0054] ​

Table 1

[0055] (Examples 2 to 5) As shown in Table 2 below, conveyor belts (samples) as Examples 2 to 5 were produced in the same manner as in Example 1, except that the thickness of the cover layer or the thickness of the antistatic layer was changed. (Comparative Example 1) A conveyor belt (sample) as Comparative Example 1 was produced in the same manner as in Example 1, except that the thickness of the cover layer was changed to 310 μm. (Comparative Example 2) A conveyor belt (sample) as Comparative Example 2 was produced in the same manner as in Example 1, except that a cover layer with a thickness of 300 μm was formed without providing an antistatic layer on one side of the core layer.

[0056] (Reference Example 1) The laminate, that is, the conveyor belt in which the antistatic layer forms the conveying surface, was evaluated as Reference Example 1.

[0057] (Evaluation 1: Antistatic property on the conveying surface) Based on the measurement method specified in ISO 21178, the resistance value on the conveying surface of each conveyor belt was measured to evaluate the antistatic property on the conveying surface. Also, the resistance values of the antistatic layer and the core layer were measured. The evaluation criterion was that the resistance value on the conveying surface was less than 1.0×10 10 Ω. The results are as shown in Table 2.

[0058] (Evaluation 2: Antistatic property of the conveyor belt) Based on the measurement method specified in ISO 21179, the running charge voltage was measured to evaluate the antistatic property of the entire conveyor belt. The results are as shown in Table 2.

[0059] (Evaluation 3: Abrasion resistance of the conveying surface) The JIS A hardness of the conveying surface was measured, and the abrasion resistance of the conveying surface was evaluated. The evaluation criterion was that the hardness of the conveying surface was 95 or higher. Also, the JIS A hardness of the surface on the conveying surface side of the antistatic layer was measured. The results are as shown in Table 2.

[0060] (Evaluation 4: Warping of the conveyor belt) Samples cut into a 30 cm × 30 cm square shape were placed stationary on a flat plate, and the lifting height from the plate surface at the end was measured with a ruler. Samples that lifted 10 mm or more at the location where the lifting was highest were judged as nonconforming. The results are as shown in Table 2.

[0061]

Table 2

[0062] (Examples of conveyor belt samples with the color tone of the conveying surface changed) In order to be used for the evaluation regarding the visibility when visually inspecting a black conveyed object, conveyor belt samples with the color tone of the conveying surface changed were produced as follows by using various cover layers to which pigments were added.

[0063] (Example 6) A conveyor belt (sample) as Example 6 presenting the color tone of the conveying surface as shown in Table 3 below was produced in the same manner as Example 1 except that titanium oxide, carbon black, and red iron oxide as pigments were added to the thermoplastic elastomer for the cover layer.

[0064] (Example 7) A conveyor belt (sample) as Example 7 presenting the color tone of the conveying surface as shown in Table 3 below was produced in the same manner as Example 6 except that the thickness of the cover layer was changed.

[0065] (Example 8) A conveyance belt (sample) as Example 8 presenting a color tone of a conveyance surface as shown in Table 3 below was produced in the same manner as in Example 1, except that a thermoplastic elastomer for a cover layer was made by adding titanium oxide as a pigment to a polyether-based polyurethane.

[0066] (Example 9) A conveyance belt (sample) as Example 9 presenting a color tone of a conveyance surface as shown in Table 3 below was produced in the same manner as in Example 8, except that the thickness of the cover layer was changed.

[0067] (Example 10) A conveyance belt (sample) as Example 10 presenting a color tone of a conveyance surface as shown in Table 3 below was produced in the same manner as in Example 1, except that titanium oxide, carbon black, and cyanine blue were added as pigments to the thermoplastic elastomer for the cover layer and the thickness of the cover layer was changed.

[0068] (Example 11) A conveyance belt (sample) as Example 11 presenting a color tone of a conveyance surface as shown in Table 3 below was produced in the same manner as in Example 1, except that titanium oxide, carbon black, and cyanine blue were added as pigments to the thermoplastic elastomer for the cover layer.

[0069] (Examples 12 - 14) Conveyance belts (samples) as Examples 12 - 14 presenting a color tone of a conveyance surface as shown in Table 3 below were produced in the same manner as in Example 11, except that the thickness of the cover layer was changed.

[0070] (Example 15) A conveyance belt (sample) as Example 15 presenting a color tone of a conveyance surface as shown in Table 3 below was produced in the same manner as in Example 1, except that titanium oxide, carbon black, and cyanine green were added as pigments to the thermoplastic elastomer for the cover layer.

[0071] (Examples 16 - 18) Except for changing the thickness of the cover layer, in the same manner as in Example 15, conveyor belts (samples) as Examples 16 to 18 presenting the color tone of the conveying surface as shown in Table 3 below were produced.

[0072] (Evaluation 5: Color tone of the conveying surface) Regarding the conveyor belts (samples) of Reference Example 1 and Examples 6 to 18, the color tone of the conveying surface (the antistatic layer in Reference Example 1) was measured with a color difference meter (ZE6000 manufactured by Nippon Denshoku Industries Co., Ltd.). C / 2 was used as the light source, the measurement method was reflection, and the reflection measurement diameter was 10 mmφ. From the obtained measurement values, the color difference from the antistatic layer (Reference Example 1) was calculated. The results are as shown in Table 3 below.

[0073] (Evaluation 6: Visibility of the black conveyed object) As a sample of the black conveyed object, a piece of the conveyor belt (sample) of Reference Example 1 cut into a 3 cm × 3 cm square shape was used. This was placed on the conveyor belts (samples) of Reference Example 1 and Examples 6 to 18 cut into a 20 cm × 20 cm square shape, and visually observed with the naked eye from about 1 m above a position horizontally about 1 m away. The visibility of the black conveyed object was determined according to the following criteria. The results are as shown in Table 3. (Judgment criteria) ○: The black conveyed object can be easily discriminated on the belt surface. △: It can be discriminated but is slightly difficult to see. ×: Difficult to discriminate.

[0074]

Table 3

Explanation of symbols

[0075] 1: Conveyor belt, 10: Core layer, 11: Inner peripheral surface, 20: Antistatic layer, 30: Cover layer, 31: Conveying surface

Claims

1. A conveyor belt comprising an antistatic layer containing conductive particles and a cover layer laminated on the antistatic layer and having a conveying surface. The cover layer contains a thermoplastic elastomer as a main component and has a thickness of 300 μm or less.

2. The conveyor belt according to claim 1, wherein the resistance value of the conveying surface is less than 1.0×10 １０ Ω.

3. The conveyor belt according to claim 1 or 2, wherein the thickness of the antistatic layer is 1.5 times or more the thickness of the cover layer.

4. The conveyor belt according to claim 1 or 2, further comprising a core layer on which the antistatic layer is laminated. The core layer has a canvas containing conductive yarns.

5. The antistatic layer contains 3% by mass or more of carbon black, and the color difference ΔE between the conveying surface and the antistatic layer is calculated by the following formula in accordance with JIS Z8781-4:2013. The conveyor belt according to claim 1 or 2, wherein the color difference ΔE is 5 or more. ＊ ΔE ＊ = [(ΔL ＊ ) ２ + (Δa ＊ ) ２ + (Δb * ) ２ ] １／２

6. The conveyor belt according to claim 5, wherein the content of the black component in the cover layer is 0.2% by mass or less.

7. The conveyor belt according to claim 1 or 2, wherein the JIS A hardness of the conveying surface is 95 or more.

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