Polyurethane adhesive, preparation method and application

Abstract

The invention belongs to the technical field of cable repairing materials, and discloses a polyurethane adhesive as well as a preparation method and application thereof. The polyurethane adhesive comprises the following components in parts by mass: 100 parts of a curing agent A, 100 parts of masterbatch B, 15-50 parts of a flame retardant C, 1-1.5 parts of toner and 5-100 parts of a primer solution D. According to the invention, the bonding peeling strength with a cable outer sheath material can be realized, and an original sheath body can be torn. By improving the bonding strength, the repair adhesive can be ensured to be tightly combined with the outer sheath of the cable, the damaged area and the thickness are repaired without special extension and thickening, the repaired cable is ensured to be consistent with the thickness of the original cable, the master batch and the curing agent adopt a carbon-black-free filling system, and black, red and yellow modified toner pigments with the same color as the original cable are matched, so that the repair effect is improved. And the repaired color is consistent with the color of the original cable. The problems that a traditional repairing adhesive is usually filled with carbon black, is single in color and is not matched with the primary color of the cable are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cable repair materials, and particularly relates to a polyurethane adhesive, a preparation method and an application thereof. Background Art

[0002] Due to the particularity of coal mine production, the problem of damage to the outer sheath of mobile cables is inevitable. A data survey in 2018 showed that during the repair of underground cables in a large coal mine, the repair volume of damaged sheaths accounted for about 93.8% of the total, and the repair volume of cable head docking accounted for 6.2%. It can be seen that the damage to the cable is mainly the damage to the sheath. According to the "Coal Mine Safety Regulations", the repair connection of rubber-sheathed cables (including the repair of rubber-sheathed cables with damaged insulation and sheath) must use flame-retardant materials for vulcanization hot repair or cold repair with the same efficiency as hot repair. The current repair methods mainly include vulcanization hot repair technology and polyurethane cold repair glue technology for mine-used rubber-sheathed flexible cables (in accordance with MT / T 351.1-2005).

[0003] In the prior art regarding the vulcanization hot repair technology, the vulcanization hot repair stage has the following steps: (1) Mold preparation, selected according to the cable model, and the mold should be 2-5 mm larger than the outer diameter of the cable; (2) The cable is placed in the vulcanizer mold, and the outer layer of the cable is protected with an aqueous release agent or a high-pressure heat-resistant film to prevent adhesion between its surface and the mold, and to make the outer layer of the cable bright and flat; (3) Press the cable, close the mold cover, tighten the screw handwheel, and adjust the jack to press the cable tightly with the mold; (4) Power on and heat up. After preheating for 10 to 15 minutes, when the temperature rises to 120 °C, the raw rubber will become soft. At this time, the hot repairer should be rotated and the handwheel should be tightened again to prevent pores in the mold. When the temperature rises to 140 to 150 °C, it can stay for 10 to 25 minutes, but not exceed 30 minutes; (5) Cool down and open the mold, cut off the power supply for heat preservation, and let it cool naturally. Generally, it takes 1.5 hours to form. When the temperature drops below 80 °C, the jack can be loosened, and the cable can be taken out of the mold to trim the outer shape. It should be noted that during the heating-up stage, the temperature should not rise too fast, otherwise honeycomb pores will appear in the raw rubber. And when the repair length exceeds the mold length, it is necessary to perform segmented vulcanization with an overlapping length of 30 to 40 mm. Its disadvantages are long time consumption, high labor intensity, short damaged repair range, and the tools are non-explosion-proof tools and cannot be used underground.

[0004] In the prior art of polyurethane cold patch glue technology for mining rubber flexible cables, this technology adopts a two-component curing system. Components A and B will undergo a chemical reaction after mixing and gradually cure to form a sealing layer, which plays a role in repairing the outer sheath of the cable, adopting a two-component curing system. Disadvantages of existing products: The outer sheath of mining cables mostly uses difficult-to-bond materials such as polyvinyl chloride (PVC), which has a low surface energy (PVC surface energy ≈ 36 mN / m), and contains migration components such as flame retardants (such as aluminum hydroxide) and plasticizers (DOP). These factors result in insufficient bonding strength between the repair glue and the cable outer sheath. To ensure sealing, the cable repair glue technology needs to expand the repair area (the extension of the damaged area ≥ 50 mm) and increase the thickness (≥ 10 mm of the original sheath thickness). This will make the repaired cable outer sheath become bulky, not only affecting the appearance of the cable, but also possibly increasing the weight and occupied space of the cable, bringing inconvenience to the laying and use of the cable. During long-term use, the glue layer is prone to separating from the cable outer sheath, affecting the repair effect. Currently, only black repair glue is available, which does not match the original color of the cable and affects the aesthetics. Moreover, the mechanical and physical properties of the cured glue layer are low, with poor flexibility (elongation at break ≤ 100%), and it is prone to cracking due to cable bending. In the complex environment of coal mines, cables need to be frequently bent and moved, and this glue layer with poor flexibility is prone to cracks, reducing the weather resistance and service life of the repair body. Summary of the Invention

[0005] To overcome the problems existing in the related technologies, the disclosed embodiments of the present invention provide a polyurethane adhesive, a preparation method, and an application, specifically related to the field of polyurethane cold patch repair for mining mobile cables. Specifically, a cable repair product with comprehensive functions, simple operation, high-strength bonding, adjustable color, and consistent thickness is proposed.

[0006] The technical solution is as follows: A polyurethane adhesive, which is composed of, by mass: 10 - 100 parts of curing agent A, 100 parts of masterbatch B, 15 - 50 parts of flame retardant C, 1 - 1.5 parts of color powder, and 5 - 100 parts of primer D.

[0007] Further, the component of curing agent A is an aromatic diamine compound;

[0008] The masterbatch B is an NCO-terminated polyurethane prepolymer formed by the reaction of macromolecular polyols and isocyanates.

[0009] Further, the flame retardant C is chlorinated paraffin;

[0010] The primer D is composed of, by mass: 60 - 65 parts of polyurethane, 0.5 - 2 parts of leveling agent, 30 - 40 parts of diluent, and 0.5 - 2 parts of accelerator;

[0011] The color powder is one of quinacridone red, permanent yellow, and carbon black.

[0012] Further, the polyurethane resin is prepared by reacting an organic polyisocyanate and an oligomeric polyol;

[0013] The organic polyisocyanate is selected from one or more of TDI, MDI, and PAPI;

[0014] The oligomeric polyol is selected from one or more of polypropylene glycol with a molecular weight of 800 - 2000 or diol adipate hexanediol with a molecular weight of 200 - 500;

[0015] The leveling agent is a polyether - modified polysiloxane;

[0016] The diluent is selected from one or more of ethyl acetate, dichloromethane, and butyl acetate;

[0017] The accelerator: one or more of triethylenediamine, bis(dimethylaminoethyl) ether, dimethylcyclohexylamine, and dibutyltin dilaurate.

[0018] Another object of the present invention is to provide a preparation method of a polyurethane adhesive, including:

[0019] S1, weigh the curing agent A, masterbatch B, flame retardant C, color powder, and primer D by mass parts;

[0020] S2, respectively prepare the primer D and the colored mixed adhesive solution;

[0021] S3, store the prepared primer and the colored mixed adhesive solution separately, and apply them according to the construction steps of the cable in the conveyor belt repair.

[0022] In step S2, the preparation of the primer D includes:

[0023] S2101, prepare the polyurethane resin, add the polyurethane resin to the diluent at room temperature, and stir for 30 - 50 min;

[0024] S2102, add the leveling agent and the accelerator to the system, stir for 10 min, package and seal for storage to obtain the primer.

[0025] In step S2, the preparation of the colored mixed adhesive solution includes:

[0026] S2201, pour the flame retardant C and the color powder into the masterbatch B adhesive solution, stir evenly to ensure that the color powder is completely dissolved and the color is uniform, and stir for 2 - 3 minutes; obtain the masterbatch B mixed solution;

[0027] In S2202, pour the curing agent A glue into the masterbatch B mixture, and stir clockwise thoroughly for 1 - 2 minutes until the color and texture of the mixed glue are uniform, obtaining a colored mixed glue.

[0028] In step S2, the preparation of the colored mixed glue further includes:

[0029] Step (1), pour the flame retardant C and color powder into the curing agent A glue, stir evenly to ensure that the color powder is completely dissolved and the color is uniform, and stir for 2 - 3 minutes; obtain the curing agent A glue mixture.

[0030] Step (2), pour the masterbatch B glue into the curing agent A glue mixture, and stir clockwise thoroughly for 1 - 2 minutes until the color and texture of the mixed glue are uniform, obtaining a colored mixed glue.

[0031] In step S3, it is applied to the construction steps in the repair of the cable on the conveyor belt, including:

[0032] Step 1, surface treatment of the damaged cable;

[0033] Step 2, prepare the primer D for the cable and brush it on the polished cable surface;

[0034] Step 3, film preparation; including cutting the film, cutting the injection port, and brushing the release agent;

[0035] Step 4, fixing the film; including tying the film tightly and sealing the gaps;

[0036] Step 5, preparation of the colored mixed glue;

[0037] Step 6, operation of extracting the colored mixed glue and injecting the colored mixed glue;

[0038] Step 7, closing the injection port;

[0039] Step 8, curing and demolding.

[0040] Another object of the present invention is to provide an application of a polyurethane adhesive in the repair of different - colored cables. This application utilizes the polyurethane adhesive. Different - colored cables include red cables, yellow cables, and black cables.

[0041] Combining all the above - mentioned technical solutions, the beneficial effects of the present invention are as follows: The rapid bonding of the polyvinyl chloride outer sheath and the polyurethane repair glue in cable repair can significantly improve the bonding strength between the two. After repair, the thickness and color can reach consistency, improving the use safety performance and aesthetics of the cable.

[0042] The bonding and peeling strength of the present invention with the cable outer sheath material can tear the original sheath body. By improving the bonding strength, it can ensure that the repair adhesive is closely combined with the cable outer sheath, and there is no need to specially extend and thicken the damaged area and thickness. After repair, it is ensured that the thickness is the same as that of the original cable. The mother glue and the curing agent adopt a carbon black-free filling system, and are equipped with black, red, and yellow modified color powder pigments of the same color system as the original cable to ensure that the color after repair is the same as that of the original cable. It solves the problems that traditional repair adhesives usually use carbon black filling, have a single color, and do not match the original color of the cable. Brief Description of the Drawings

[0043] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments in line with the present disclosure, and are used together with the specification to explain the principles of the present disclosure;

[0044] Figure 1 It is a flowchart of the polyurethane adhesive method provided by an embodiment of the present invention;

[0045] Figure 2 It is a flowchart of the preparation of the primer D provided by an embodiment of the present invention;

[0046] Figure 3 It is a flowchart of the preparation of the colored mixed glue provided by an embodiment of the present invention;

[0047] Figure 4 It is an effect diagram of the black polyurethane adhesive of the present invention;

[0048] Figure 5 It is an effect diagram of the black cable repair of the present invention;

[0049] Figure 6 It is an effect diagram of the red cable repair of the present invention;

[0050] Figure 7 It is an effect diagram of the yellow cable repair of the present invention;

[0051] Figure 8 It is an effect diagram of the bonding strength test of the product of the present invention. Detailed Embodiments

[0052] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed embodiments of the present invention in conjunction with the drawings. Many specific details are set forth in the following description to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0053] The present invention solves the existing technical problems such as poor adhesion, color mismatch, uneven thickness, and impatience of existing products.

[0054] Example 1. The polyurethane adhesive provided by the embodiment of the present invention is a kind of material for cable repair glue.

[0055] It is composed of, by mass parts: 10 - 100 parts of curing agent A, 100 parts of masterbatch B, 15 - 50 parts of flame retardant C, 1 - 1.5 parts of color powder, and 5 - 100 parts of primer liquid D (determined according to the size of the cable repair area).

[0056] Exemplarily, the present invention uses 100 parts of masterbatch B as a reference component. Under 100 parts of masterbatch B, the selection range of the curing agent can be 10 - 100 parts. The reason for choosing 100 parts of the curing agent as a reference component is mainly that for the later product positioning of small packages of 0.25 KG / set, the masterbatch is 100 grams, which is convenient for product matching, so the curing agent is selected at 100 parts. It can be understood that 100 parts of masterbatch B is only a reference example, and the proportion of each component equipped according to production needs can be adjusted accordingly with reference to this ratio.

[0057] The component of the curing agent A is an aromatic diamine compound.

[0058] The masterbatch B is an end - NCO polyurethane prepolymer formed by the reaction of macromolecular polyols and isocyanates (such as TDI, MDI, etc.).

[0059] The flame retardant C is chlorinated paraffin.

[0060] The primer liquid D is composed of, by mass parts: 60 - 65 parts of polyurethane, 0.5 - 2 parts of leveling agent, 30 - 40 parts of diluent, and 0.5 - 2 parts of accelerator.

[0061] The polyurethane resin is prepared by the reaction of organic polyisocyanates and low - molecular - weight polyols.

[0062] The organic polyisocyanates are selected from one or more of TDI, MDI, and PAPI.

[0063] The low - molecular - weight polyols are selected from one or more of polypropylene glycol with a molecular weight of 800 - 2000 or polyhexamethylene adipate diol with a molecular weight of 200 - 500.

[0064] The leveling agent uses polyether - modified polysiloxane.

[0065] The diluent uses one or more of ethyl acetate, dichloromethane, and butyl acetate.

[0066] The accelerator: one or more of triethylenediamine, bis(dimethylaminoethyl) ether, dimethylcyclohexylamine, and dibutyltin dilaurate.

[0067] The curing agent A and the masterbatch B of the present invention provide high - strength mechanical properties.

[0068] Flame retardant C improves the flame retardancy and temperature resistance of the repair adhesive.

[0069] Primer D is a cable primer used to pretreat the cable surface and enhance the adhesion of the adhesive.

[0070] Color powder: Provide three kinds of color powders, namely quinacridone red (1.5 parts), permanent yellow (1.5 parts), and carbon black (1 part). Users can flexibly mix according to the cable color to ensure that the appearance of the repaired cable is consistent with the original color.

[0071] The said color powder: is a modified color powder to ensure compatibility with the repair adhesive liquid.

[0072] As can be seen from the above embodiments, the cable repair adhesive has broad application prospects in the coal mining industry. In order to meet the requirements of safety regulations and improve the safety and reliability of cables, coal mining enterprises will be more inclined to choose this high-performance repair adhesive. With the development of the coal mining industry and the continuous improvement of safety requirements, the market demand for this repair adhesive will also continue to increase. The superiority of the products of the present invention is obvious and has been recognized by major coal mines. Its products have obtained the material coding of the National Energy Group, laying a brand effect for further product promotion, and the expected revenue is in the tens of millions of output value. The present invention solves the existing technical problems of the existing products, such as poor adhesion, mismatched color, uneven thickness, and impatience.

[0073] With the improvement of civilized production in the industry, people's requirements for the aesthetics after repair are also further improved. Due to the technical prejudice that has existed in the market for nearly 30 years in the products of this technical field, the existing technical problems such as poor adhesion, mismatched color, uneven thickness, and impatience have always been technical problems that cable repair engineers urgently want to solve but have not been able to solve. The damage of the outer sheath of mobile mining cables is a common problem in coal mining production enterprises. Traditional cable repair adhesive products have existed in the market for nearly 30 years and are generally recognized as temporary repair products. The single repair color is no longer suitable for the diversification of current cable colors, and there has been no professional to innovate and upgrade the product technology. With the continuous improvement of civilized production and safety requirements in the coal mining industry, the market urgently needs a product with comprehensive functions, simple operation, adjustable color, and fast curing, which can achieve the purpose of one-time repair and permanent use.

[0074] Example 2, as Figure 1 shown, the preparation method of the polyurethane adhesive provided by the embodiment of the present invention includes:

[0075] S1, weigh curing agent A, masterbatch B, flame retardant C, color powder, and primer D according to parts by mass;

[0076] S2, respectively prepare primer D and the colored mixed adhesive liquid;

[0077] S3. Store the prepared primer solution and the colored mixed adhesive solution separately, and apply them according to the construction steps in the conveyor belt repair of the cable.

[0078] Example 3. As Figure 2 shown, the preparation of the primer solution D in step S2 includes:

[0079] S2101. Prepare polyurethane resin, add the polyurethane resin to the diluent at room temperature, and stir for 30 - 50 min;

[0080] S2102. Add the leveling agent and the accelerator to the system, stir for 10 min, package and seal for storage to obtain the primer solution.

[0081] Example 4. As Figure 3 shown, in step S2, the preparation of the colored mixed adhesive solution includes:

[0082] S2201. Pour the flame retardant C and the color powder into the mother rubber B adhesive solution, stir evenly to ensure that the color powder is completely dissolved and the color is uniform, and stir for 2 - 3 minutes; obtain the mother rubber B mixed solution;

[0083] S2202. Pour the curing agent A adhesive solution into the mother rubber B mixed solution, stir clockwise evenly for 1 - 2 minutes until the color and texture of the mixed adhesive solution are uniform, and obtain the colored mixed adhesive solution.

[0084] Among them, the curing agent A adhesive solution is a light yellow transparent liquid, and the mother rubber B is a colorless transparent liquid.

[0085] Another exemplary one is that in step S2, the preparation of the colored mixed adhesive solution may further include:

[0086] Step (1). Pour the flame retardant C and the color powder into the curing agent A adhesive solution, stir evenly to ensure that the color powder is completely dissolved and the color is uniform, and stir for 2 - 3 minutes; obtain the curing agent A adhesive solution mixed solution;

[0087] Step (2). Pour the mother rubber B adhesive solution into the curing agent A adhesive solution mixed solution, stir clockwise evenly for 1 - 2 minutes until the color and texture of the mixed adhesive solution are uniform, and obtain the colored mixed adhesive solution.

[0088] This preparation method can further simplify the on-site shaping use of subsequent products.

[0089] Another exemplary one is that the present invention provides an application of a polyurethane adhesive in the repair of cables of different colors, and this application utilizes the polyurethane adhesive.

[0090] Example 5. In step S3, during the construction steps of the cable in the conveyor belt repair, according to market demand and operational flexibility, the product is positioned as a small package, 0.25 kg / set. The selected ratio of curing agent A glue to mother glue B glue is 1:1. The reason is that the product is convenient for sub-packaging and matching. The actual net weight of glue A is 100 grams, and the actual net weight of glue B is 100 grams. The original design is based on the 1:1 selection to facilitate the sub-packaging and use of the product. Component C is a flame retardant. The final experimental data of the addition amount is sent to Shanghai Coal Science Testing Technology Co., Ltd. The issued detection report of passing the flame retardancy test determines the range of the final addition ratio. Component D is a primer and does not participate in the reaction with other components. The reason for positioning it at 10 parts is to match the sufficient primer weight according to the actual repaired damaged length of each set.

[0091] Specifically, it includes the following steps:

[0092] Step 1, surface treatment: Use a carbon-free brush lithium battery electric grinding head or a metal file to polish the damaged part of the cable until a fresh interface is exposed, ensuring that the surface is flat, free of oil, dust, and oxide layer.

[0093] Step 2, primer treatment: Apply the primer solution. Prepare the primer solution D for the cable. Use a supporting primer brush to evenly apply the primer solution thinly on the polished cable surface. It is recommended to apply it twice (with a recommended interval of 2 minutes) to ensure complete coverage. Wait for 5 to 10 minutes until the primer is surface dry (the touch is not sticky). During this period, the film can be prepared.

[0094] Step 3, film preparation; including:

[0095] Cut the film: Cut a transparent film of appropriate size according to the size of the cable repair area.

[0096] Cut the injection port: Use a utility knife to cut 1 to 2 injection ports on the film. If the cable is poured horizontally, it is recommended to cut two or more injection ports; if the cable is poured vertically, it is recommended to cut a slightly larger injection port. The design of the injection port helps to discharge the bubbles generated during injection.

[0097] Apply the release agent: Apply a layer of grease-based release agent (such as petroleum jelly or machine oil, lubricating oil, etc.) on the inner side of the film to facilitate easy demolding after curing.

[0098] Step 4, fix the film; including:

[0099] Tighten the film: Wrap the cut film around the cable repair area and use a cable tie to tighten both ends of the film. Leave at least 3 cm at both ends for cable tie fixation.

[0100] Seal the gap: Use tape to firmly stick the gap in the middle of the film to prevent glue leakage when injecting the glue.

[0101] Step 5, Preparation of the mixed adhesive solution with color;

[0102] Step 6, Injection of the mixed adhesive solution with color; includes:

[0103] Extraction of the mixed adhesive solution with color: Use the supporting syringe to extract the prepared mixed adhesive solution with color.

[0104] Operation of injecting the mixed adhesive solution with color: Inject the mixed adhesive solution with color from the pre-cut injection port on the film, and inject slowly to ensure that the mixed adhesive solution with color fully fills the repair area, while discharging air bubbles. During the injection process, the film can be gently tapped to help discharge the air bubbles.

[0105] Step 7, Sealing the injection port After the injection of the glue is completed, immediately seal all the injection ports with tape to prevent the mixed adhesive solution with color from flowing back or air from entering.

[0106] Step 8, Curing and demolding, Waiting for curing: Initial demolding can be carried out in 30 minutes at room temperature (20 - 25 °C).

[0107] Among the above construction steps for the repair of the cable on the conveyor belt, the relevant product indicators are shown in Table 1.

[0108] Table 1 Product indicators

[0109]

[0110]

[0111] In the above relevant steps, the syringe: is used to precisely control the amount of the adhesive, improve the density after repair, and facilitate operation.

[0112] The brush: is used to evenly apply the primer solution to ensure that the surface of the cable is fully wetted.

[0113] The transparent film: is used to cover the repair area, facilitate the observation of the filling situation of the adhesive solution, facilitate the injection and molding of the adhesive solution, and ensure the aesthetics after repair. (The transparent film is made of PET (polyethylene terephthalate), with a thickness of 0.2 mm - 0.3 mm, hardness).

[0114] The scraper: is used to level the repair adhesive to make the repair surface smooth and traceless.

[0115] Example 6, The polyurethane adhesive provided by the embodiment of the present invention is composed of, by mass: 100 parts of curing agent A, 100 parts of masterbatch B, 20 parts of flame retardant C, 1 part of carbon black, and 10 parts of primer solution D. The effect diagram is as Figure 4 Schematic diagram of the black polyurethane adhesive.

[0116] Example 7. The polyurethane adhesive provided by the embodiment of the present invention is composed of, by mass: 100 parts of curing agent A, 100 parts of masterbatch B, 60 parts of flame retardant C, 1.5 parts of quinacridone red, and 10 parts of primer D.

[0117] Example 8. The polyurethane adhesive provided by the embodiment of the present invention is composed of, by mass: 100 parts of curing agent A, 100 parts of masterbatch B, 40 parts of flame retardant C, 1.5 parts of permanent yellow, and 10 parts of primer D.

[0118] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0119] To further illustrate the relevant effects of the embodiments of the present invention, the following experiments are carried out.

[0120] The feature of color customization solves the problem of color mismatch in the existing repair technology. The traditional repair glue has a single color and a large difference from the original color of the cable. The current product can be customized according to the color of the original cable, and the appearance of the repaired cable is consistent with the original cable, improving the aesthetics.

[0121] Such as Figure 5 The repair effect diagram of the black cable, Figure 6 is the repair effect diagram of the red cable, Figure 7 is the repair effect diagram of the yellow cable;

[0122] The primer is applied to the rapid bonding of the polyvinyl chloride outer sheath and the cable repair glue in cable repair. Its bonding strength can tear the sheath, significantly improving the bonding strength between the two, ensuring the sealing performance, and there is no need to expand and thicken the damaged area during repair, avoiding the swelling of the outer sheath after repair and the increase in the amount of repair material used. It can evenly cover the damaged part, making the thickness of the repaired cable outer sheath uniform and not affecting the bending performance and appearance of the cable.

[0123] Figure 8 is the test effect diagram of the bonding strength of the product of the present invention. The fracture of the bonding failure is tested. Through Figure 8 It shows that the bonding strength of the product of the present invention is greater than the body strength of the cable sheath material itself. The physical property test report is shown in Table 2, indicating that the performance of the repaired product is higher than the physical properties of the original cable sheath.

[0124] Table 2 Physical Property Test Report

[0125] Inspection Items Technical Requirements Inspection Results Conclusion <![CDATA[Tensile strength before aging, N / mm 2 > ≥11.0 13.7 √ Elongation at Break before Aging, % ≥250 310 √ <![CDATA[After aging in an air oven at 75℃ for 240 h, tensile strength, N / mm 2 > - 14.3 - Elongation at Break after 240h Aging in 75℃ Air Oven, % ≥200 320 √ Tensile Strength Change Rate after 240h Aging in 75℃ Air Oven, % ≥-15 +4 √ Elongation at Break Change Rate after 240h Aging in 75℃ Air Oven, % ≥-25 +3 √ Tear Strength Test, N / mm ≥5.0 5.2 √

[0126] In the table, the "√" sign indicates that the item is qualified;

[0127] The "×" sign indicates that the item is unqualified;

[0128] The "-" sign indicates that this item standard is not required.

[0129] Furthermore, the PET transparent film selected in the present invention can be flexibly cut according to the thickness and length of the repaired cable, which not only ensures the aesthetics after repair but also greatly reduces the mold cost. Its transparent feature also facilitates observing the state during the injection of the glue solution. The syringe glue injection process selected in the present invention has a higher density and better quality after molding compared to the original natural pouring.

[0130] As described above, only the relatively preferred specific implementation manner of the present invention is provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A polyurethane adhesive, characterized in that, The polyurethane adhesive is composed of, by mass parts: 10 - 100 parts of curing agent A, 100 parts of masterbatch B, 15 - 50 parts of flame retardant C, 1 - 1.5 parts of color powder, and 5 - 100 parts of primer solution D.

2. The polyurethane adhesive according to claim 1, wherein The component of the curing agent A is an aromatic diamine compound; The masterbatch B is an NCO - terminated polyurethane prepolymer formed by the reaction of a macromolecular polyol and an isocyanate.

3. The polyurethane adhesive according to claim 1, wherein The flame retardant C is chlorinated paraffin; The primer solution D is composed of, by mass parts: 60 - 65 parts of polyurethane, 0.5 - 2 parts of leveling agent, 30 - 40 parts of diluent, and 0.5 - 2 parts of accelerator; The color powder is one of quinacridone red, permanent yellow, and carbon black.

4. The polyurethane adhesive according to claim 3, characterized in that, The polyurethane resin is prepared by the reaction of an organic polyisocyanate and an oligomeric polyol; The organic polyisocyanate is selected from one or more of TDI, MDI, and PAPI; The oligomeric polyol is selected from one or more of polypropylene glycol with a molecular weight of 800 - 2000 or poly(hexamethylene adipate) diol with a molecular weight of 200 - 500; The leveling agent uses polyether - modified polysiloxane; The diluent uses one or more of ethyl acetate, dichloromethane, and butyl acetate; The accelerator: one or more of triethylenediamine, bis(dimethylaminoethyl) ether, dimethylcyclohexylamine, and dibutyltin dilaurate.

5. A method for preparing a polyurethane adhesive, characterized in that, It is used for the preparation of the polyurethane adhesive according to any one of claims 1 - 4. The preparation method includes: S1, Weigh the curing agent A, masterbatch B, flame retardant C, color powder, and primer solution D by mass parts; S2, Prepare the primer solution D and the colored mixed glue solution respectively; S3, Store the prepared primer solution and the colored mixed glue solution separately, and apply them according to the construction steps of the cable in the conveyor belt repair.

6. The preparation method of the polyurethane adhesive according to claim 5, characterized in that, In step S2, the preparation of the primer solution D includes: S2101, Prepare the polyurethane resin. Add the polyurethane resin to the diluent at room temperature and stir for 30 - 50 min; S2102, Add the leveling agent and the accelerator to the system, stir for 10 min, package and seal for storage to obtain the primer solution.

7. The preparation method of the polyurethane adhesive according to claim 5, characterized in that, In step S2, the preparation of the colored mixed glue solution includes: S2201, Pour the flame retardant C and the color powder into the masterbatch B glue solution, stir evenly to ensure that the color powder is completely dissolved and the color is uniform, and stir for 2 - 3 minutes; obtain the masterbatch B mixed solution; S2202, Pour the curing agent A glue solution into the masterbatch B mixed solution, stir clockwise evenly for 1 - 2 minutes until the color and texture of the mixed glue solution are uniform, and obtain the colored mixed glue solution.

8. The preparation method of the polyurethane adhesive according to claim 5, characterized in that, In step S2, the preparation of the colored mixed glue solution further includes: Step (1), Pour the flame retardant C and the color powder into the curing agent A glue solution, stir evenly to ensure that the color powder is completely dissolved and the color is uniform, and stir for 2 - 3 minutes; obtain the curing agent A glue solution mixture; Step (2), Pour the masterbatch B glue solution into the curing agent A glue solution mixture, stir clockwise evenly for 1 - 2 minutes until the color and texture of the mixed glue solution are uniform, and obtain the colored mixed glue solution.

9. The preparation method of the polyurethane adhesive according to claim 5, wherein In step S3, the application according to the construction steps of the cable in the conveyor belt repair includes: Step 1, surface treatment of the damaged cable; Step 2, preparation of the primer D for the cable, and brushing it on the polished cable surface; Step 3, film preparation; including cutting the film, cutting the injection port, and brushing the release agent; Step 4, fixing the film; including tying the film tightly and sealing the gap; Step 5, preparation of the colored mixed adhesive solution; Step 6, operation of extracting the colored mixed adhesive solution and injecting the colored mixed adhesive solution; Step 7, closing the injection port; Step 8, curing and demolding.

10. Application of a polyurethane adhesive in repairing cables of different colors, characterized in that, This application utilizes the polyurethane adhesive according to any one of claims 1-4.

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