A PVC / PVG solid woven flame-retardant conveyor belt joint adhesive, its preparation method, and its application.

Abstract

This invention discloses an adhesive for PVC / PVG solid-core flame-retardant conveyor belt joints, its preparation method, and its application, belonging to the field of new materials technology. By weight, the adhesive comprises the following components: 60-80 parts of polyvinyl chloride paste resin, 20-40 parts of vinyl chloride-vinyl acetate copolymer paste resin, 50-70 parts of phosphate esters, 10-20 parts of polyester plasticizer, 5-10 parts of epoxidized soybean oil, 3-5 parts of organotin stabilizer, 2-3 parts of hexamethoxymethyl melamine, 10-20 parts of bio-based modified adhesive resin, and 2-4 parts of anti-fatigue agent. This invention provides an adhesive suitable for joint fabrication under short-time, low-temperature, and low-pressure conditions, exhibiting good fatigue resistance and low cost.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, and specifically relates to a PVC / PVG solid woven flame-retardant conveyor belt joint adhesive, its preparation method, and its application. Background Technology

[0002] In the coal mining industry, PVC (polyvinyl chloride) / PVG solid woven flame-retardant conveyor belts are widely used as important transportation equipment in coal mining, transportation, and processing. To ensure stable and efficient operation of the conveyor belt, the quality of the joint technology directly affects its overall performance and safety. The joints of PVC / PVG solid woven flame-retardant conveyor belts are typically bonded using specialized adhesives to ensure the strength and durability of the connection.

[0003] The splicing of solid woven conveyor belts generally uses a vulcanized splicing method. This involves cutting both ends of the conveyor belt into finger-shaped structures according to the splicing process requirements, then removing the surface cover rubber, grinding, applying adhesive, covering with mesh fabric, and finally applying a cover rubber and vulcanizing. The adhesive is used to firmly bond the splice areas at both ends of the conveyor belt, ensuring the continuity and stability of the conveyor belt during operation.

[0004] Although existing PVC / PVG solid woven conveyor belt splice adhesives have achieved certain technical improvements, they still have shortcomings in fatigue resistance. Conveyor belts experience frequent vibrations and oscillations, especially under high-intensity operations or high-speed running. Due to the significant dynamic loads, the splice area is subjected to repeated tensile, compressive, bending, and shear stresses in different directions. The adhesive at the splice needs to withstand these complex stresses, and over long-term use, the fatigue resistance of the splice is easily affected. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides an adhesive for PVC / PVG solid woven flame-retardant conveyor belt joints, its preparation method, and its application. This invention focuses on developing an adhesive suitable for joint fabrication under short-time, low-temperature, and low-pressure conditions, exhibiting good fatigue resistance.

[0006] This invention provides an adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts, comprising the following components by weight:

[0007] The mixture contains 60-80 parts of polyvinyl chloride paste resin, 20-40 parts of vinyl chloride-vinyl acetate copolymer paste resin, 50-70 parts of phosphate esters, 10-20 parts of polyester plasticizer, 5-10 parts of epoxidized soybean oil, 3-5 parts of organotin stabilizer, 2-3 parts of hexamethoxymethyl melamine, 10-20 parts of bio-based modified adhesive resin, and 2-4 parts of anti-fatigue agent.

[0008] In some embodiments, the polyvinyl chloride paste resin has an average degree of polymerization of 1200-1400 and a type B viscosity of 2000-6000 mPa·s at 30°C.

[0009] In some embodiments, the average degree of polymerization of the vinyl chloride-vinyl acetate copolymer paste resin is 900~1100, and the type B viscosity at 30°C is 1500~4000 mPa·s.

[0010] In some embodiments, the phosphate esters are triaryl phosphate esters and / or trihaloalkyl phosphate esters.

[0011] In some embodiments, the viscosity of the polyester plasticizer at 25°C is 2700~3500 cPS; the epoxy value of the epoxidized soybean oil is greater than 6.

[0012] In some embodiments, the organotin heat stabilizer is thiol methyltin.

[0013] In some embodiments, the adhesive also includes 4 to 6 parts of black paste.

[0014] In some embodiments, the adhesive does not include powdered flame retardants.

[0015] This invention provides a method for preparing the adhesive for the splice of a PVC / PVG solid woven flame-retardant conveyor belt, comprising:

[0016] Weigh out the following components by weight: polyvinyl chloride paste resin, vinyl chloride-vinyl acetate copolymer paste resin, phosphate esters, polyester plasticizer, epoxidized soybean oil, organotin stabilizer, hexamethoxymethyl melamine, bio-based modified adhesive resin, and anti-fatigue agent. Mix them together to obtain the adhesive paste.

[0017] Furthermore, the present invention provides the application of the adhesive as described above in the vulcanization preparation of PVC / PVG solid woven flame-retardant conveyor belt joints.

[0018] Currently, the formulations and components of most domestically produced PVC / PVG solid-woven flame-retardant conveyor belt joint adhesives are kept secret, resulting in a certain degree of technological monopoly in their application. There is an urgent need for research, improvement, and optimization to achieve domestic production. Furthermore, the high procurement cost of existing adhesives on the market increases the overall manufacturing cost of the conveyor belt joint. This places additional economic pressure on coal mining enterprises during application, especially in large-scale applications where cost issues become more prominent.

[0019] This invention provides an adhesive for bonding PVC / PVG solid-core flame-retardant conveyor belt joints. The main components are polyvinyl chloride paste resin and vinyl chloride-vinyl acetate copolymer paste resin in a certain proportion, along with plasticizers, heat stabilizers, adhesives, and other additives. The main component of this invention is the blending of vinyl chloride-vinyl acetate copolymer paste resin, which facilitates the fabrication of joints under short-time, low-temperature, and low-pressure conditions, while also improving the impact resistance of the joints. In this invention, phosphate esters serve as the main plasticizer, with polyester plasticizers and epoxidized soybean oil as auxiliary plasticizers. This plasticizer system, used in conjunction with organotin heat stabilizers, achieves a significant synergistic effect, improving the fatigue resistance of the joints. Therefore, the vulcanized joints fabricated using the adhesive developed in this invention under short-time, low-temperature, and low-pressure conditions exhibit good fatigue resistance. Furthermore, this invention reduces costs and facilitates application. Detailed Implementation

[0020] The technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] This invention provides an adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts, comprising the following components by weight:

[0022] The mixture contains 60-80 parts of polyvinyl chloride paste resin, 20-40 parts of vinyl chloride-vinyl acetate copolymer paste resin, 50-70 parts of phosphate esters, 10-20 parts of polyester plasticizer, 5-10 parts of epoxidized soybean oil, 3-5 parts of organotin stabilizer, 2-3 parts of hexamethoxymethyl melamine, 10-20 parts of bio-based modified adhesive resin, and 2-4 parts of anti-fatigue agent.

[0023] The adhesive provided by this invention can be used for joint construction under short-time, low-temperature, and low-pressure conditions, and has good fatigue resistance and low cost.

[0024] In a specific embodiment of the present invention, the main material of the adhesive is selected from polyvinyl chloride paste resin and vinyl chloride-vinyl acetate copolymer paste resin. That is, the adhesive comprises 60-80 parts by weight of polyvinyl chloride paste resin and 20-40 parts by weight of vinyl chloride-vinyl acetate copolymer paste resin.

[0025] The polyvinyl chloride paste resin is typically a paste form of polyvinyl chloride (PVC) plastic, with a particle size range generally between 0.1 and 2.0 μm, making it easy to form a paste and process. The average degree of polymerization of the polyvinyl chloride paste resin is 1200–1400, primarily between 1300 ± 100; its type B viscosity at 30°C is 2000–6000 mPa·s (obtained using a type B viscometer). For example, the weight parts of the polyvinyl chloride paste resin can be 60 parts, 73 parts, 75 parts, 80 parts, etc.

[0026] In this embodiment of the invention, 20-40 parts by weight of vinyl chloride-vinyl acetate copolymer paste resin are incorporated, for example, 20 parts, 25 parts, 30 parts, and 40 parts. The vinyl chloride-vinyl acetate copolymer paste resin can be abbreviated as VC-VAC copolymer paste resin, and its performance mainly depends on the average degree of polymerization of the copolymer. Because the macromolecules of vinyl chloride-vinyl acetate copolymer paste resin have an amorphous structure, the distance between polymer chains is increased, increasing molecular flexibility and retaining the advantages of PVC resin to a certain extent. Simultaneously, it improves the performance of PVC through internal plasticizing, having a lower melting temperature than PVC resin, thereby improving processing performance and reducing the plasticizing temperature of the adhesive, allowing it to meet the requirements for joint fabrication under short-time, low-temperature, and low-pressure conditions, and also improving the impact resistance of the joint. Preferably, the average degree of polymerization of the vinyl chloride-vinyl acetate copolymer paste resin is 900-1100, mainly within 1000±100; its type B viscosity at 30°C can be 1500-4000 mPa·s.

[0027] Regarding the selection of the plasticizing component system, the adhesive formulation of a specific embodiment of the present invention includes: 50-70 parts of phosphate esters, 10-20 parts of polyester plasticizer, and 5-10 parts of epoxidized soybean oil. The phosphate esters primarily function as plasticizers. As the main plasticizer, phosphate esters exhibit good heat and chemical resistance, excellent flame retardancy, and higher durability than traditional plasticizers. Furthermore, when used as the main plasticizer, the adhesive no longer requires the use of powdered flame retardants such as antimony trioxide, zinc borate, and aluminum hydroxide, reducing stress concentration caused by these powdered flame retardants and thus improving the fatigue resistance of the applied joint.

[0028] In some preferred embodiments, the phosphate ester is a triaryl phosphate ester and / or a trihaloalkyl phosphate ester, and may further be a triaryl phosphate ester and a trichloroethyl phosphate ester.

[0029] In a specific embodiment of the present invention, the polyester plasticizer and epoxidized soybean oil are used as auxiliary plasticizers. Compared with traditional plasticizers, polyester plasticizers have more polar groups and larger molecular weights, exhibiting low volatility, oil resistance, solvent extraction resistance, and migration resistance. They can be combined with low molecular weight plasticizers to ultimately impart durable stability to the joint. Epoxidized soybean oil has good compatibility with PVC resin, low volatility, low migration, excellent thermal and light stability, and good water and oil resistance. When used in conjunction with other plasticizers in the adhesive, it can reduce plasticizer migration; and when used with organotin heat stabilizers, it has a significant synergistic effect.

[0030] Furthermore, the polyester plasticizer is preferably adipic acid polyester with a viscosity of 2700~3500 cPS at 25°C; and the epoxy value of the epoxidized soybean oil is greater than 6, for example, 7~9.

[0031] The adhesive described in specific embodiments of the present invention includes 3 to 5 parts of an organotin stabilizer; in some embodiments, the organotin heat stabilizer is preferably methyl tin mercaptan.

[0032] In this embodiment of the invention, the following are also specifically selected for addition: 2-3 parts of hexamethoxymethyl melamine and 10-20 parts of bio-based modified adhesive resin. The bio-based modified adhesive resin can be AltertackEco 11-A from Shanghai Changyu Chemical Co., Ltd., whose main component is lignin, with an ash content ≤7.0% and a bulk density of 0.4-0.5 g / cm³. 3 Resorcinol is commonly used in the industry as a methylene receptor adhesive. However, resorcinol irritates the skin and mucous membranes and can be rapidly absorbed through the skin, causing poisoning symptoms. Furthermore, resorcinol requires grinding before being formulated into adhesives, increasing production costs. In addition to hexamethoxymethyl melamine, this invention uses a bio-based modified adhesive resin to enhance adhesion, offering advantages such as being environmentally friendly and having abundant raw material sources.

[0033] Furthermore, the adhesive specifically includes an anti-fatigue agent (also known as a fatigue-resistant agent) and other additives such as color paste. In some embodiments, the anti-fatigue agent is preferably 2-4 parts; it can be PL-600 fatigue-resistant agent from Taizhou Huangyan Donghai Chemical Co., Ltd., which is a complex composed of methyl citrileimide or citrileimide methylene, activated phenolic resin, and a meta-methyl-white adhesive system, with a heating loss ≤4.5% at 60°C / 1h. Preferably, the adhesive also includes 4-6 parts of black paste, which can be HJ6-08 from Hengyang Lihui Environmental New Materials Co., Ltd., mainly composed of a mixture of pigment carbon black and dioctyl terephthalate, with a fineness ≤15μm.

[0034] Accordingly, the present invention provides a method for preparing the adhesive for the splice of the PVC / PVG solid woven flame-retardant conveyor belt, comprising:

[0035] Weigh out the following components by weight: polyvinyl chloride paste resin, vinyl chloride-vinyl acetate copolymer paste resin, phosphate esters, polyester plasticizer, epoxidized soybean oil, organotin stabilizer, hexamethoxymethyl melamine, bio-based modified adhesive resin, and anti-fatigue agent. Mix them together to obtain the adhesive paste.

[0036] This invention relates to a method for designing and preparing an adhesive for joints of PVC / PVG solid-core flame-retardant conveyor belts used in coal mines, using raw materials such as vinyl chloride-vinyl acetate copolymer paste resin, polyester plasticizer, phosphate esters, and bio-based modified adhesive resin.

[0037] In some embodiments, the preparation method of the adhesive paste is carried out using conventional stirring and mixing equipment, and the specific steps may be as follows:

[0038] Step 1: Add phosphate esters, polyester plasticizer, epoxidized soybean oil, organotin stabilizer and black paste into a dispersing mixer and stir for 1-5 minutes;

[0039] Step 2: Add vinyl chloride-vinyl acetate copolymer paste resin and 1 / 2 of polyvinyl chloride paste resin into a dispersing mixer and stir for 3-10 minutes;

[0040] Step 3: Raise the dispersion disc and scrape the wall, then add the bio-based modified adhesive resin and the remaining 1 / 2 of the polyvinyl chloride paste resin into the dispersion mixer and stir for 3-10 minutes.

[0041] Step 4: Raise the dispersion disc and scrape the wall. Add hexamethoxymethyl melamine and the anti-fatigue agent into the dispersion mixer and stir for 3-10 minutes. Raise the dispersion disc and scrape the wall.

[0042] Step 5: Turn on the vacuum and stir for 30-60 minutes to obtain the product.

[0043] The embodiments of the present invention do not impose any special restrictions on the order of addition of the raw material components or the mixing method, but it is preferred to prepare the mixture according to the above steps; the adhesive remains soft after curing. In some embodiments, the viscosity of the adhesive can be 5000~9000 cPS / 25℃ (e.g., 6000~7000 cPS); its fineness is ≤50μm.

[0044] Furthermore, embodiments of the present invention provide the application of the adhesive as described above in the vulcanization preparation of PVC / PVG solid woven flame-retardant conveyor belt joints.

[0045] Most vulcanizing adhesives currently on the market require long vulcanization times, high vulcanization temperatures, and high vulcanization pressures, increasing construction time and energy costs. However, some customers require short time, low temperature, and low pressure when making joints. For example, in Australia, when making joints in underground coal mines, the time, temperature, and pressure settings of the vulcanizing machine are much lower than in China.

[0046] In some specific embodiments of the present invention, a 1800S*1600mm (2+2) PVG solid woven conveyor belt (with a longitudinal tensile strength of 1800N / mm, a width of 1600mm, and a thickness of 2mm for both the upper and lower cover rubber layers) can be used. The aforementioned adhesive is then applied under vulcanization conditions of 150-160℃ / 0.7-1.8MPa / 20-23min to prepare a PVC / PVG solid woven flame-retardant conveyor belt joint sample. Durability testing showed that the adhesive strength of the cover rubber at the joint remained good.

[0047] To better understand the technical content of this invention, specific embodiments are provided below for further explanation. All raw materials are commercially available. The polyvinyl chloride paste resin is LF-51L from Langhui Petrochemical Co., Ltd., with an average degree of polymerization of 1300±100; the vinyl chloride-vinyl acetate copolymer paste resin is PCMA-12 from Shenyang Chemical Co., Ltd., with an average degree of polymerization of 1000±100. The polyester plasticizer is adipic acid polyester (UN620 from Liancheng Chemical Technology Co., Ltd.), with a viscosity of 2700~3500 cPS / 25℃; the epoxidized soybean oil is ESO-KLO1 from Zibo Kailian Chemical Co., Ltd., with an epoxy value ≥6.1%. The organotin stabilizer is methyl tin mercaptan, specifically methyl tin mercaptan heat stabilizer JX-181 from Taian Lantian Additives Co., Ltd., with a tin content of 19±0.5% and a sulfur content of 12±0.5%; the bio-based modified adhesive resin is Altertack Eco 11-A from Shanghai Changyu Chemical Co., Ltd.; the fatigue resistant agent is PL-600 from Taizhou Huangyan Donghai Chemical Co., Ltd.; and the black paste is HJ6-08 from Hengyang Lihui Environmental New Materials Co., Ltd.

[0048] Example 1

[0049] The adhesive formulation ratio is based on parts by weight:

[0050] 80 parts of polyvinyl chloride paste resin, 20 parts of vinyl chloride-vinyl acetate copolymer paste resin, 30 parts of triaryl phosphate (triisopropylphenyl phosphate, the same below), 10 parts of trichloroethyl phosphate, 20 parts of polyester plasticizer, 10 parts of epoxidized soybean oil, 3 parts of organotin stabilizer, 3 parts of hexamethoxymethyl melamine, 20 parts of bio-based modified adhesive resin, 2 parts of anti-fatigue agent, and 6 parts of black paste.

[0051] The preparation method of the adhesive for the joint of the PVC / PVG solid woven flame-retardant conveyor belt includes the following steps:

[0052] Step 1: Add phosphate esters, polyester plasticizer, epoxidized soybean oil, organotin stabilizer, and black paste into a dispersing mixer and stir for 2 minutes;

[0053] Step 2: Add vinyl chloride-vinyl acetate copolymer paste resin and 1 / 2 of polyvinyl chloride paste resin into a dispersing mixer and stir for 5 minutes;

[0054] Step 3: Raise the dispersion disc and scrape the wall, then add the bio-based modified adhesive resin and the remaining 1 / 2 of the polyvinyl chloride paste resin into the dispersion mixer and stir for 5 minutes;

[0055] Step 4: Raise the dispersion disc and scrape the wall. Add hexamethoxymethyl melamine and the anti-fatigue agent into the dispersion mixer and stir for 5 minutes. Raise the dispersion disc and scrape the wall.

[0056] Step 5: Turn on the vacuum and stir for 40 minutes to obtain the paste; its viscosity is 5000~9000 cPS / 25℃ and its fineness is ≤50μm.

[0057] Note: The temperature inside the mixing vessel must be controlled below 40℃ in all the above steps; the dispersion mixer is a concentric double-shaft frame-type mixing blade (the same applies below).

[0058] Take an 1800S*1600mm (2+2) PVG solid core strip, use the joint adhesive in Example 1, prepare a joint sample under vulcanization conditions of 150℃ / 0.7MPa / 20min, and conduct the following durability test (the test conditions are based on industry standard MT / T318).

[0059] ①Joint dynamic durability test: The joint dynamic durability strengthening test was carried out on a double-drum dynamic fatigue test bench; the test results showed that the joint remained intact and did not break when the number of tension pulsation cycles was greater than 40,000.

[0060] ② Adhesion test of the cover adhesive before and after the joint dynamic durability test: The test results show that the adhesive strength of the cover adhesive at the joint did not decrease significantly.

[0061] Table 1 Test results of Example 1

[0062]

[0063] Example 2

[0064] The adhesive formulation ratio is based on parts by weight:

[0065] 75 parts polyvinyl chloride paste resin, 25 parts vinyl chloride-vinyl acetate copolymer paste resin, 30 parts triaryl phosphate, 15 parts trichloroethyl phosphate, 17 parts polyester plasticizer, 8 parts epoxidized soybean oil, 4 parts organotin stabilizer, 2.5 parts hexamethoxymethyl melamine, 17 parts bio-based modified adhesive resin, 3 parts anti-fatigue agent, and 5 parts black paste.

[0066] The preparation method of the adhesive for the joint of the PVC / PVG solid-core flame-retardant conveyor belt for coal mines includes the following steps:

[0067] Step 1: Add phosphate ester, polyester plasticizer, epoxidized soybean oil, organotin stabilizer, and black paste into a dispersing mixer and stir for 2 minutes;

[0068] Step 2: Add vinyl chloride-vinyl acetate copolymer paste resin and 1 / 2 of polyvinyl chloride paste resin into a dispersing mixer and stir for 5 minutes;

[0069] Step 3: Raise the dispersion disc and scrape the wall, then add the bio-based modified adhesive resin and the remaining 1 / 2 of the polyvinyl chloride paste resin into the dispersion mixer and stir for 5 minutes;

[0070] Step 4: Raise the dispersion disc and scrape the wall. Add hexamethoxymethyl melamine and the anti-fatigue agent into the dispersion mixer and stir for 5 minutes. Raise the dispersion disc and scrape the wall.

[0071] Step 5: Turn on the vacuum and stir for 40 minutes to obtain the adhesive.

[0072] Note: The temperature inside the stirring vessel should be controlled below 40℃ in all the above steps.

[0073] Using the joint adhesive from Example 1, 1800S*1600mm (2+2) PVG solid core tape, joint samples were prepared under vulcanization conditions of 150℃ / 0.7MPa / 20min, and the following durability tests were performed:

[0074] ①Joint dynamic durability test: The joint dynamic durability strengthening test was carried out on a double-drum dynamic fatigue test bench. The test results showed that when the number of tension pulsation cycles was greater than 40,000, the joint was intact and did not break.

[0075] ② Adhesion test of the cover adhesive on the samples before and after the joint dynamic durability test; the test results show that the adhesive strength of the cover adhesive at the joint did not decrease significantly.

[0076] Table 2 Test Results of Example 2

[0077]

[0078] Example 3

[0079] The adhesive formulation ratio is based on parts by weight:

[0080] 70 parts polyvinyl chloride paste resin, 30 parts vinyl chloride-vinyl acetate copolymer paste resin, 30 parts triaryl phosphate, 20 parts trichloroethyl phosphate, 15 parts polyester plasticizer, 5 parts epoxidized soybean oil, 5 parts organotin stabilizer, 2 parts hexamethoxymethyl melamine, 14 parts bio-based modified adhesive resin, 4 parts anti-fatigue agent, and 4 parts black paste.

[0081] The preparation method of the adhesive for the joint of the PVC / PVG solid-core flame-retardant conveyor belt for coal mines includes the following steps:

[0082] Step 1: Add phosphate ester, polyester plasticizer, epoxidized soybean oil, organotin stabilizer, and black paste into a dispersing mixer and stir for 2 minutes;

[0083] Step 2: Add vinyl chloride-vinyl acetate copolymer paste resin and 1 / 2 of polyvinyl chloride paste resin into a dispersing mixer and stir for 5 minutes;

[0084] Step 3: Raise the dispersion disc and scrape the wall, then add the bio-based modified adhesive resin and the remaining 1 / 2 of the polyvinyl chloride paste resin into the dispersion mixer and stir for 5 minutes;

[0085] Step 4: Raise the dispersion disc and scrape the wall. Add hexamethoxymethyl melamine and the anti-fatigue agent into the dispersion mixer and stir for 5 minutes. Raise the dispersion disc and scrape the wall.

[0086] Step 5: Turn on the vacuum and stir for 40 minutes to obtain the adhesive.

[0087] Note: The temperature inside the stirring vessel should be controlled below 40℃ in all the above steps.

[0088] Using the joint adhesive from Example 1, 1800S*1600mm (2+2) PVG solid core tape, joint samples were prepared under vulcanization conditions of 150℃ / 0.7MPa / 20min, and the following durability tests were performed:

[0089] ①Joint dynamic durability test: The joint dynamic durability strengthening test was carried out on a double-drum dynamic fatigue test bench. The test results showed that when the number of tension pulsation cycles was greater than 40,000, the joint was intact and did not break.

[0090] ② Adhesion test of the cover adhesive on the samples before and after the joint dynamic durability test; the test results show that the adhesive strength of the cover adhesive at the joint did not decrease significantly.

[0091] Table 3 Test results of Example 3

[0092]

[0093] Example 4

[0094] Take an 1800S*1600mm (2+2) PVG solid core strip, use the joint adhesive in Example 1, and prepare a joint sample under vulcanization conditions of 160℃ / 1.8MPa / 23min for the following durability test.

[0095] ①Joint dynamic durability test: The joint dynamic durability strengthening test was carried out on a double-roller dynamic fatigue test bench. The test results showed that the joint was intact and did not break when the number of tension pulsation cycles was greater than 40,000.

[0096] ② Adhesion test of the cover adhesive before and after the joint dynamic durability test: The test results show that the adhesive strength of the cover adhesive at the joint did not decrease significantly.

[0097] Table 4 Test Results of Example 4

[0098]

[0099] The test results of Examples 1 and 4 show that the durability of the vulcanized joints made using the adhesive of the present invention under low temperature, short time, low pressure and high temperature, long time, high pressure conditions are at the same level.

[0100] Comparative Example 1

[0101] Take 1800S*1600mm (2+2) PVG solid core tape, and use commercially available joint adhesive (viscosity 5000~9000cPS / 25℃, fineness ≤50μm) to prepare joint samples under vulcanization conditions of 160℃ / 1.8MPa / 23min. The following durability tests are then conducted:

[0102] ①Joint dynamic durability test: The joint dynamic durability strengthening test was carried out on a double-drum dynamic fatigue test bench. The test results showed that when the number of tension pulsation cycles was greater than 40,000, the joint was intact and did not break.

[0103] ② Adhesion test of the cover adhesive before and after the joint dynamic durability test: The test results show that the adhesive strength of the cover adhesive at the joint did not decrease significantly.

[0104] Table 5 shows the test results of Comparative Example 1.

[0105]

[0106] The test results of Example 4 and Comparative Example 1 show that the durability of the vulcanized joints prepared by using the adhesive of the present invention under high temperature, long time and high pressure conditions is at the same level as that of commercially available adhesives.

[0107] Comparative Example 2

[0108] Take 1800S*1600mm (2+2) PVG solid core tape, and use commercially available joint adhesive (the adhesive of Comparative Example 1) to prepare joint samples under vulcanization conditions of 150℃ / 0.7MPa / 20min, and conduct the following durability tests:

[0109] ①Joint dynamic durability test: The joint dynamic durability strengthening test was carried out on a double-drum dynamic fatigue test bench. The test results showed that the joint broke when the tension pulsation cycle number was 12032.

[0110] ② Adhesion test of the cover adhesive on the samples before and after the joint dynamic durability test.

[0111] Table 6 shows the test results of Comparative Example 2.

[0112]

[0113] The test results of Example 1 and Comparative Example 2 show that the durability of the vulcanized joint prepared using the adhesive of the present invention under low temperature, short time and low pressure conditions is significantly better than that of the vulcanized joint prepared using commercially available adhesive.

[0114] As can be seen from the above embodiments, the adhesive provided in this invention, when used to construct vulcanized joints under short-time, low-temperature, and low-pressure conditions, exhibits good fatigue resistance. Furthermore, this invention reduces costs and facilitates application.

[0115] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A type of adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts, characterized in that, Based on parts by weight, it comprises the following components: The adhesive comprises 60-80 parts of polyvinyl chloride paste resin, 20-40 parts of vinyl chloride-vinyl acetate copolymer paste resin, 50-70 parts of phosphate esters, 10-20 parts of polyester plasticizer, 5-10 parts of epoxidized soybean oil, 3-5 parts of organotin stabilizer, 2-3 parts of hexamethoxymethyl melamine, 10-20 parts of bio-based modified adhesive resin, and 2-4 parts of anti-fatigue agent; the adhesive also includes 4-6 parts of black paste; the adhesive does not include powder flame retardant.

2. The adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts according to claim 1, characterized in that, The polyvinyl chloride paste resin has an average degree of polymerization of 1200~1400 and a type B viscosity of 2000~6000 mPa·s at 30°C.

3. The adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts according to claim 1, characterized in that, The average degree of polymerization of the vinyl chloride-vinyl acetate copolymer paste resin is 900~1100, and the viscosity of type B at 30°C is 1500~4000 mPa·s.

4. The adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts according to any one of claims 1-3, characterized in that, The phosphate esters are triaryl phosphate esters and / or trihaloalkyl phosphate esters.

5. The adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts according to claim 4, characterized in that, The viscosity of the polyester plasticizer at 25°C is 2700~3500 cPS; the epoxy value of the epoxidized soybean oil is greater than 6.

6. The adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts according to any one of claims 1-3, characterized in that, The organotin stabilizer is thiol methyltin.

7. A method for preparing the adhesive for splicing PVC / PVG solid woven flame-retardant conveyor belts according to any one of claims 1-6, characterized in that, include: Weigh out the following components by weight: polyvinyl chloride paste resin, vinyl chloride-vinyl acetate copolymer paste resin, phosphate esters, polyester plasticizer, epoxidized soybean oil, organotin stabilizer, hexamethoxymethyl melamine, bio-based modified adhesive resin, and anti-fatigue agent. Mix them together to obtain the adhesive paste.

8. The application of the adhesive as described in any one of claims 1-6 in the vulcanization preparation of PVC / PVG solid woven flame-retardant conveyor belt joints.

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