Oil-resistant and acid-and-alkali-resistant conveying belt and preparation method thereof

Abstract

The application relates to the technical field of conveying belts, and discloses an oil-resistant and acid-alkali-resistant conveying belt and a preparation method thereof. The covering rubber comprises upper covering rubber and lower covering rubber. Raw materials of the covering rubber comprise the following components in parts by weight: 40-50 parts of butyronitrile rubber, 10-15 parts of a softening agent, 15-25 parts of modified white carbon black, 15-20 parts of a corrosion-resistant agent A, 0.5-1 part of a vulcanizing agent A, 1-2 parts of an accelerator A and 1.5-2 parts of an activator A. The modified white carbon black is obtained by modifying white carbon black with 5-amino isophthalic acid. The technical scheme solves the problem of poor oil resistance and acid-alkali resistance of the conveying belt in the prior art.

Description

Technical Field

[0001] This invention relates to the field of conveyor belt technology, specifically to an oil-resistant and acid / alkali-resistant conveyor belt and its preparation method. Background Technology

[0002] Rubber conveyor belts, the second largest product in the rubber industry, are mainly used for material transportation in mines, docks, metallurgy, machinery, and warehousing. There are many types of conveyor belts, classified by core material as fabric core conveyor belts, steel cord core conveyor belts, traction steel cord core conveyor belts (steel cable conveyor belts), and steel mesh conveyor belts, and by shape as tubular conveyor belts, sidewall conveyor belts, patterned conveyor belts, lifting conveyor belts, and cover conveyor belts, among others.

[0003] However, in some special scenarios, conveyor belts with special functions are required. For example, when using ordinary conveyor belts to transport oils, organic solvents, or acid and alkali media, the swelling and corrosiveness of the cover rubber on the belt surface can easily cause the cover rubber to expand and deform, and the compounding agents inside the cover rubber to be extracted, resulting in a decrease in the physical properties of the cover rubber layer and a shortened service life. Summary of the Invention

[0004] This invention proposes an oil-resistant and acid / alkali-resistant conveyor belt and its preparation method, which solves the problem of poor oil-resistant, acid / alkali-resistant performance of conveyor belts in related technologies.

[0005] The technical solution of the present invention is as follows:

[0006] This invention proposes an oil- and acid / alkali-resistant conveyor belt, comprising a steel wire rope core, core rubber, and cover rubber. The cover rubber includes an upper cover rubber and a lower cover rubber. The raw materials of the cover rubber include the following components by weight: 40-50 parts nitrile rubber, 10-15 parts softener A, 15-25 parts modified silica, 15-20 parts corrosion resistant agent A, 0.5-1 part vulcanizing agent A, 1-2 parts accelerator A, and 1.5-2 parts activator A; wherein the modified silica is silica modified with 5-aminoisophthalic acid.

[0007] The raw materials of the core rubber include the following components by weight: 35-45 parts nitrile rubber, 10-15 parts softener B, 5-8 parts resin, 10-15 parts silica, 5-8 parts adhesive, 10-15 parts corrosion resistant agent B, 0.5-1 part vulcanizing agent B, 1-1.5 parts accelerator B, 1-3 parts activator B, and 0.5-1 part antioxidant.

[0008] As a further technical solution, the amount of 5-aminoisophthalic acid added is 3-5% of the carbon black.

[0009] As a further technical solution, the preparation method of the modified silica includes the following steps:

[0010] 5-Aminophthalic acid was added to an ethanol solution, followed by the addition of silica and thorough mixing. After modification, the mixture was filtered and dried to obtain modified silica.

[0011] As a further technical solution, the modification temperature is 50~60℃ and the modification time is 1~2h.

[0012] As a further technical solution, the ethanol solution is a 95wt% aqueous ethanol solution.

[0013] As a further technical solution, the raw material of the core adhesive also includes 4 to 6 parts of butyramic acid.

[0014] The core adhesive in this invention also includes butyramic acid. The addition of butyramic acid can not only further improve the bonding strength between the core adhesive and the cover adhesive, but also further improve the oil resistance, acid and alkali resistance of the conveyor belt and extend the service life of the conveyor belt.

[0015] As a further technical solution, both the vulcanizing agent A and the vulcanizing agent B are sulfur.

[0016] As a further technical solution, both corrosion resistant agent A and corrosion resistant agent B are composed of iron oxide and barium sulfate.

[0017] As a further technical solution, the mass ratio of iron oxide to barium sulfate is 1:1.

[0018] As a further technical solution, the method for preparing the covering adhesive includes the following steps:

[0019] S1. After mixing nitrile rubber, softener, modified silica, corrosion resistant agent A, and activator A, a mixture is obtained;

[0020] S2. After adding vulcanizing agent A and accelerator A for vulcanization, the product is extruded, sheeted, and coated to obtain the cover rubber.

[0021] As a further technical solution, the accelerator A and accelerator B are each independently one or more of accelerator M, accelerator DM, and accelerator CZ.

[0022] As a further technical solution, the antioxidant includes one or more of antioxidant MB, antioxidant RD, and antioxidant 4020.

[0023] As a further technical solution, the softener A and softener B are each independently one or two of C5 petroleum resin and paraffin oil.

[0024] As a further technical solution, the resin is epoxy resin E20.

[0025] As a further technical solution, the adhesive is cobalt borylate.

[0026] As a further technical solution, both activator A and activator B are composed of zinc oxide and stearic acid.

[0027] As a further technical solution, the mass ratio of zinc oxide to stearic acid is 3~5:1.

[0028] The present invention also proposes a method for preparing an oil-resistant and acid-alkali-resistant conveyor belt, comprising the following steps: after bonding the upper cover rubber and the core rubber, and the lower cover rubber and the core rubber respectively into a mold, pressing them into a mold in the order of upper cover rubber, core rubber, steel wire rope core, core rubber, and lower cover rubber from top to bottom, and then vulcanizing them to obtain an oil-resistant and acid-alkali-resistant conveyor belt.

[0029] As a further technical solution, the thickness of both the upper and lower cover adhesives is 1.5 mm, and the thickness of the core adhesive is 1 mm.

[0030] The working principle and beneficial effects of this invention are as follows:

[0031] 1. In this invention, both the cover rubber and the core rubber are based on nitrile rubber, which has excellent oil resistance. Corrosion resistant agents are also added to improve the oil, acid and alkali resistance of the conveyor belt. After the silica in the cover rubber is modified with 5-aminoisophthalic acid, the cover rubber can maintain high tensile strength and elongation at break, and further reduce the volume expansion rate and tensile strength change rate after acid treatment, thereby improving the acid resistance of the conveyor belt and extending its service life. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] In the following embodiments and comparative examples:

[0034] Nitrile rubber: NBR2808, manufactured by Lanzhou Petrochemical;

[0035] Paraffin oil: 26#, manufactured by Guangzhou Tongxin Chemical Co., Ltd.

[0036] Silica: SiO≥98%, particle size 3000 mesh;

[0037] Iron oxide: purity 99.9%, particle size 500 mesh;

[0038] Barium sulfate: BaSO4 ≥ 98%, particle size 3000 mesh;

[0039] Zinc oxide; purity 99.9%, particle size 1200 mesh.

[0040] Example 1

[0041] A method for preparing an oil-resistant and acid / alkali-resistant conveyor belt includes the following steps:

[0042] S1. Mix 40 parts nitrile rubber, 10 parts paraffin oil, 15 parts modified silica, 7.5 parts iron oxide, 7.5 parts barium sulfate, and 1.5 parts activator at 135°C for 20 minutes to obtain a mixture; add 0.5 parts sulfur and 1 part accelerator DM to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a cover rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 3:1.

[0043] S2. Mix 35 parts of nitrile rubber, 10 parts of paraffin oil, 5 parts of epoxy resin E20, 10 parts of silica, 5 parts of cobalt borate, 5 parts of iron oxide, 5 parts of barium sulfate, 1 part of activator, and 0.5 parts of antioxidant MB at 135°C for 20 minutes to obtain a mixture; add 0.5 parts of sulfur and 1 part of accelerator DM to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a core-supported rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 3:1.

[0044] S3. After bonding the upper cover rubber and the core rubber, and the lower cover rubber and the core rubber separately, press them into shape in the following order from top to bottom: upper cover rubber, core rubber, steel wire rope core, core rubber, and lower cover rubber. After vulcanization, an oil-resistant and acid- and alkali-resistant conveyor belt is obtained. The thickness of the upper cover rubber and the lower cover rubber is 1.5 mm, and the thickness of the core rubber is 1 mm.

[0045] The preparation method of modified silica includes the following steps:

[0046] 1.2 g of 5-aminoisophthalic acid was added to 300 mL of 95 wt% ethanol aqueous solution, and then 40 g of silica was added and mixed evenly. After modification at 50 °C for 2 h, the mixture was filtered and dried to obtain modified silica.

[0047] Example 2

[0048] A method for preparing an oil-resistant and acid / alkali-resistant conveyor belt includes the following steps:

[0049] S1. Mix 55 parts of nitrile rubber, 12 parts of paraffin oil, 20 parts of modified silica, 8 parts of iron oxide, 8 parts of barium sulfate, and 1.8 parts of activator at 135°C for 20 minutes to obtain a mixture; add 0.8 parts of sulfur and 1.5 parts of accelerator CZ to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a cover rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 4:1.

[0050] S2. Mix 40 parts nitrile rubber, 12 parts paraffin oil, 7 parts epoxy resin E20, 12 parts silica, 7 parts cobalt borate, 6 parts iron oxide, 6 parts barium sulfate, 2 parts activator, and 0.8 parts antioxidant RD at 135°C for 20 minutes to obtain a mixture; add 0.8 parts sulfur and 1.3 parts accelerator CZ to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a core-supported rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 4:1.

[0051] S3. After bonding the upper cover rubber and the core rubber, and the lower cover rubber and the core rubber separately, press them into shape in the following order from top to bottom: upper cover rubber, core rubber, steel wire rope core, core rubber, and lower cover rubber. After vulcanization, an oil-resistant and acid- and alkali-resistant conveyor belt is obtained. The thickness of the upper cover rubber and the lower cover rubber is 1.5 mm, and the thickness of the core rubber is 1 mm.

[0052] The preparation method of modified silica includes the following steps:

[0053] 1.2 g of 5-aminoisophthalic acid was added to 300 mL of 95 wt% ethanol aqueous solution, and then 40 g of silica was added and mixed evenly. After modification at 55 °C for 1.5 h, the mixture was filtered and dried to obtain modified silica.

[0054] Example 3

[0055] A method for preparing an oil-resistant and acid / alkali-resistant conveyor belt includes the following steps:

[0056] S1. Mix 50 parts of nitrile rubber, 15 parts of paraffin oil, 25 parts of modified silica, 10 parts of iron oxide, 10 parts of barium sulfate, and 2 parts of activator at 135°C for 20 minutes to obtain a mixture; add 1 part of sulfur and 2 parts of accelerator M to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a cover rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 5:1.

[0057] S2. Mix 45 parts nitrile rubber, 15 parts paraffin oil, 8 parts epoxy resin E20, 15 parts silica, 8 parts cobalt borate, 7.5 parts iron oxide, 7.5 parts barium sulfate, 3 parts activator, and 1 part antioxidant MB at 135°C for 20 minutes to obtain a mixture; add 1 part sulfur and 1.5 parts accelerator M to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a core-supported rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 5:1.

[0058] S3. After bonding the upper cover rubber and the core rubber, and the lower cover rubber and the core rubber separately, press them into shape in the following order from top to bottom: upper cover rubber, core rubber, steel wire rope core, core rubber, and lower cover rubber. After vulcanization, an oil-resistant and acid- and alkali-resistant conveyor belt is obtained. The thickness of the upper cover rubber and the lower cover rubber is 1.5 mm, and the thickness of the core rubber is 1 mm.

[0059] The preparation method of modified silica includes the following steps:

[0060] 1.2 g of 5-aminoisophthalic acid was added to 300 mL of 95 wt% ethanol aqueous solution, and then 40 g of silica was added and mixed evenly. After modification at 60 °C for 1 h, the mixture was filtered and dried to obtain modified silica.

[0061] Example 4

[0062] The only difference between this embodiment and Example 1 is that the amount of 5-aminoisophthalic acid added is 1.6g.

[0063] Example 5

[0064] The only difference between this embodiment and Example 1 is that the amount of 5-aminoisophthalic acid added is 2g.

[0065] Example 6

[0066] The only difference between this embodiment and Example 1 is the core rubber. The preparation method of the core rubber in this embodiment includes the following steps: 35 parts of nitrile rubber, 10 parts of paraffin oil, 5 parts of epoxy resin E20, 10 parts of silica, 5 parts of cobalt borate, 5 parts of iron oxide, 5 parts of barium sulfate, 1 part of activator (composed of zinc oxide and stearic acid in a mass ratio of 3:1), 0.5 parts of antioxidant MB, and 4 parts of butyramic acid are mixed at 135°C for 20 minutes to obtain a mixture; 0.5 parts of sulfur and 1 part of accelerator DM are added to the mixture, and after vulcanization at 150°C for 20 minutes, the mixture is extruded and sheeted to obtain the core rubber.

[0067] Example 7

[0068] The only difference between this embodiment and Example 6 is that the amount of butyramic acid is 5 parts.

[0069] Example 8

[0070] The only difference between this embodiment and Example 6 is that the amount of butyramic acid is 6 parts.

[0071] Comparative Example 1

[0072] A method for preparing an oil-resistant and acid / alkali-resistant conveyor belt includes the following steps:

[0073] S1. Mix 40 parts nitrile rubber, 10 parts paraffin oil, 15 parts silica, 7.5 parts iron oxide, 7.5 parts barium sulfate, and 1.5 parts activator at 135°C for 20 minutes to obtain a mixture; add 0.5 parts sulfur and 1 part accelerator DM to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a cover rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 3:1.

[0074] S2. Mix 35 parts of nitrile rubber, 10 parts of paraffin oil, 5 parts of epoxy resin E20, 10 parts of silica, 5 parts of cobalt borate, 5 parts of iron oxide, 5 parts of barium sulfate, 1 part of activator, and 0.5 parts of antioxidant MB at 135°C for 20 minutes to obtain a mixture; add 0.5 parts of sulfur and 1 part of accelerator DM to the mixture, vulcanize at 150°C for 20 minutes, extrude, and sheet to obtain a core-supported rubber; wherein the activator is composed of zinc oxide and stearic acid in a mass ratio of 3:1.

[0075] S3. After bonding the upper cover rubber and the core rubber, and the lower cover rubber and the core rubber separately, press them into shape in the following order from top to bottom: upper cover rubber, core rubber, steel wire rope core, core rubber, and lower cover rubber. After vulcanization, an oil-resistant and acid- and alkali-resistant conveyor belt is obtained. The thickness of the upper cover rubber and the lower cover rubber is 1.5 mm, and the thickness of the core rubber is 1 mm.

[0076] Comparative Example 2

[0077] The only difference between this comparative example and Example 6 is that 5-aminoisophthalic acid is replaced with an equal amount of silane coupling agent Si 69.

[0078] Test case

[0079] The performance of the conveyor belts in Examples 1-8 and Comparative Examples 1-2 was determined. The acid resistance of the cover rubber was determined according to the test method in HG / T3782-2015 "Acid and Alkali Resistant Conveyor Belts" (test conditions: immersion in 50wt% sulfuric acid, 50℃×96h). The adhesive strength of the cover rubber and the core rubber was determined according to the test method in GB / T 17044-2020 "Test on Adhesion Strength between Cover Layer and Core Layer of Steel Wire Rope Conveyor Belt". The test results are shown in Tables 1-2.

[0080] Table 1. Performance of the covering adhesives in Examples 1-6 and Comparative Examples 1-2

[0081]

[0082] Compared with the cover adhesive in Example 6, the silica in Comparative Example 1 was not modified, while the silica in Comparative Example 2 was modified with silane coupling agent Si 69. The results showed that the tensile strength and elongation at break of the cover adhesives in Comparative Examples 1 and 2 were lower than those in Example 6, and the volume expansion rate and tensile strength change rate of the cover adhesives after sulfuric acid immersion were greater than those in Example 6. This indicates that the silica modified with 5-aminoisophthalic acid in the cover adhesive of the present invention can give the cover adhesive higher tensile strength and elongation at break, and further reduce the volume expansion rate and tensile strength change rate of the cover adhesive after acid treatment.

[0083] Table 2. Adhesive strength between cover adhesive and core adhesive in Examples 1, 6-8 and Comparative Examples 1-2

[0084]

[0085] Compared with Example 1, butyramic acid was added in Examples 6-8. As a result, the bonding strength of the cover adhesive and the core adhesive in Examples 6-8 was higher than that in Example 1, indicating that adding butyramic acid to the core adhesive can improve the bonding strength between the cover adhesive and the core adhesive.

[0086] Compared with Example 6, the silica in Comparative Example 1 was not modified, while the silica in Comparative Example 2 was modified with silane coupling agent Si69. The results showed that the bonding strength of the cover rubber and the core rubber in Comparative Examples 1 and 2 was lower than that in Example 6. This indicates that when the silica in the cover rubber is modified with 5-aminoisophthalic acid and butyramic acid is added to the core rubber, the bonding strength of the cover rubber and the core rubber can be further improved, the oil and acid and alkali resistance of the conveyor belt can be further improved, and the service life of the conveyor belt can be extended.

[0087] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oil- and acid- and alkali-resistant conveyor belt, comprising a steel wire rope core, core rubber, and cover rubber, characterized in that, The cover rubber includes an upper cover rubber and a lower cover rubber; the raw materials of the cover rubber include the following components by weight: 40-50 parts nitrile rubber, 10-15 parts softener A, 15-25 parts modified silica, 15-20 parts corrosion resistant agent A, 0.5-1 part vulcanizing agent A, 1-2 parts accelerator A, and 1.5-2 parts activator A; The modified silica is obtained by modifying silica with 5-aminoisophthalic acid; The raw materials of the core rubber include the following components by weight: 35-45 parts nitrile rubber, 10-15 parts softener B, 5-8 parts resin, 10-15 parts silica, 5-8 parts adhesive, 10-15 parts corrosion resistant agent B, 0.5-1 part vulcanizing agent B, 1-1.5 parts accelerator B, 1-3 parts activator B, and 0.5-1 part antioxidant.

2. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 1, characterized in that, The amount of 5-aminoisophthalic acid added is 3-5% of the carbon black.

3. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 1, characterized in that, The raw materials for the core adhesive also include 4 to 6 parts of butyramic acid.

4. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 1, characterized in that, Both sulfurizing agent A and sulfurizing agent B are sulfur.

5. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 1, characterized in that, Both corrosion resistant agent A and corrosion resistant agent B are composed of iron oxide and barium sulfate.

6. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 1, characterized in that, The method for preparing the cover adhesive includes the following steps: S1. After mixing nitrile rubber, softener, modified silica, corrosion resistant agent A, and activator A, a mixture is obtained; S2. After adding vulcanizing agent A and accelerator A for vulcanization, the product is extruded, sheeted, and coated to obtain the cover rubber.

7. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 1, characterized in that, The accelerator A and accelerator B are each independently one or more of accelerator M, accelerator DM, and accelerator CZ.

8. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 1, characterized in that, Both activator A and activator B are composed of zinc oxide and stearic acid.

9. The oil-resistant and acid / alkali-resistant conveyor belt according to claim 8, characterized in that, The mass ratio of zinc oxide to stearic acid is 3~5:

1.

10. A method for preparing an oil-resistant and acid / alkali-resistant conveyor belt according to any one of claims 1 to 9, characterized in that, The process includes the following steps: After bonding the upper cover rubber and the core rubber, and the lower cover rubber and the core rubber separately, they are pressed and molded in the following order from top to bottom: upper cover rubber, core rubber, steel wire rope core, core rubber, and lower cover rubber. After vulcanization, an oil-resistant and acid- and alkali-resistant conveyor belt is obtained.

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