Special epoxy AB adhesive for back mesh as well as preparation method and application of special epoxy AB adhesive

Abstract

The invention relates to the technical field of epoxy AB adhesives, in particular to a special epoxy AB adhesive for a back mesh as well as a preparation method and application of the special epoxy AB adhesive for the back mesh, and the epoxy A adhesive is prepared from the following components in percentage by weight: a component A: 40-60% of bisphenol A epoxy resin; 10-20% of carboxyl-terminated nitrile rubber; 5%-10% of nano SiO2; 1-3% of a silane coupling agent; 5-10% of a reactive diluent; 3-8% of a plasticizer; the component B comprises 50-70% of a fatty amine curing agent; 10-20% of polyether amine; 1-3% of an accelerant; and 10-20% of nano calcium carbonate. Through an interpenetrating network structure formed by the carboxyl-terminated nitrile rubber and the epoxy resin, the peel strength of the adhesive reaches 15-20 N / mm and is improved by 50% or above compared with that of traditional epoxy glue, the peeling stress between a back mesh material and a matrix can be effectively resisted, and the stability and reliability of the structure are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy AB adhesives, and particularly relates to an epoxy AB adhesive special for backing nets, a preparation method thereof, and an application thereof. Background Art

[0002] Epoxy resins refer to a general term for compounds that contain two or more epoxy groups in a molecular structure and can form a three-dimensional cross-linked cured compound under appropriate chemical reagents and suitable conditions. There are many types of them. According to their chemical structures, they can be divided into glycidyl ether type, glycidyl ester type, glycidyl amine type, alicyclic epoxy resins, epoxy resins containing inorganic elements, new epoxy resins (such as hydantoin epoxy resins, imide epoxy resins, etc.). Among various epoxy resins, bisphenol A epoxy resin is a major variety with the largest output and the widest use. According to its molecular weight, it can be divided into low, medium, high, and ultra-high molecular weight epoxy resins (poly(phenylene oxide) resins). Low molecular weight resins can be cured at room temperature or high temperature, but high molecular weight epoxy resins must be cured at high temperature, while ultra-high molecular weight poly(phenylene oxide) resins do not require a curing agent and can form a tough film at high temperature.

[0003] In the prior art, there is a preparation method of a high yellowing-resistant epoxy AB adhesive with the publication number CN118620564A; this high yellowing-resistant epoxy AB adhesive consists of component A and component B; among them, component A is composed of the following raw materials in parts by weight: 20 - 30 parts of composite epoxy resin, 3 - 6 parts of diluent, 3 - 5 parts of toughening agent, 2 - 5 parts of coupling agent, and 2 - 5 parts of antioxidant; component B is composed of the following raw materials in parts by weight: 3 - 6 parts of diluent, 4 - 6 parts of curing agent, 2 - 4 parts of thickening and thinning adjusting solvent, and 3 - 7 parts of functional filler; the high yellowing-resistant epoxy AB adhesive prepared by the present invention not only has good mechanical properties but also has excellent yellowing resistance, effectively ensuring its quality and quality.

[0004] Compared with the existing epoxy AB adhesives, there are still the following problems:

[0005] The problem that the existing epoxy AB adhesive used for backing net bonding has relatively poor temperature resistance performance, which easily leads to the problem of structural damage of the epoxy AB adhesive. For this reason, we propose an epoxy AB adhesive special for backing nets, a preparation method thereof, and an application thereof. Summary of the Invention

[0006] The purpose of the present invention is to provide an epoxy AB adhesive special for backing nets, a preparation method thereof, and an application thereof, so as to solve the problems raised in the above background art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A special epoxy AB adhesive for the back net. This epoxy AB adhesive, the epoxy A adhesive is composed of the following components according to the weight ratio:

[0009] Component A:

[0010] Bisphenol A epoxy resin 40 - 60%;

[0011] Carboxyl-terminated nitrile rubber 10 - 20%;

[0012] Nano-SiO2 5 - 10%;

[0013] Silane coupling agent 1 - 3%;

[0014] Reactive diluent 5 - 10%;

[0015] Plasticizer 3 - 8%;

[0016] Component B:

[0017] Modified aliphatic amine curing agent 50 - 70%;

[0018] Polyetheramine 10 - 20%;

[0019] Accelerator 1 - 3%;

[0020] Nano-calcium carbonate 10 - 20%.

[0021] Preferably, the particle size of the nano-SiO2 is 50 - 100 nm, and the specific surface area is 200 - 300 m 2 / g.

[0022] Preferably, the silane coupling agent is one or more of KH-550, methyltrichlorosilane, aminosilane, vinylsilane, epoxysilane, and allyltrimethoxysilane.

[0023] Preferably, the reactive diluent is one or more of benzyl glycidyl ether, n-butyl glycidyl ether, phenyl glycidyl ether, cresol glycidyl ether, polyethylene glycol diglycidyl ether, benzyl alcohol, and tributyl phosphate.

[0024] Preferably, the plasticizer is one or more of dioctyl phthalate, dimethyl phthalate, diisononyl phthalate, and diisodecyl phthalate.

[0025] Preferably, the modified aliphatic amine curing agent is T-31.

[0026] Preferably, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0027] A preparation method of a special epoxy AB adhesive for the back net, comprising the following steps:

[0028] Step S1, Preparation of Component A: Epoxy resin, carboxyl-terminated nitrile rubber, nano-SiO2, KH-550, diluent and plasticizer are added into a reaction kettle according to precise proportions. Under the temperature condition of 60 - 80 °C, with a stirring speed of 300 - 500 r / min, continuously stir for 30 - 60 min until a uniform and transparent system is formed;

[0029] Step S2, Preparation of Component B: The curing agent, polyetheramine, accelerator and nano-calcium carbonate are successively added into a high-speed disperser. Under normal temperature environment, disperse at a high speed of 1000 - 1500 r / min for 15 - 20 min to ensure that each component is fully mixed to form a uniform paste.

[0030] A method for using a special epoxy AB adhesive for back net includes the following steps:

[0031] Step 1, Mixing: Weigh Component A and Component B in an equal proportion of 1:1 and mix them. Use mechanical stirring or manual stirring to fully stir evenly to obtain Mixture A;

[0032] Step 2, Dilution: Add a specified amount of water to Mixture C and stir evenly;

[0033] Step 3, Adding Cement: Add a specified amount of 425 white cement (for white plates) or cement (for gray plates), stir evenly, and obtain Mixture D;

[0034] Step 4, Gluing and Curing: After the back net glue is mixed, apply Mixture D on the bonding surfaces of the back net material and the matrix material to fill and repair the gaps in the stone. Under normal circumstances, the board can be collected in 2 hours. It is recommended to enter the next process after 3 days. In the case of assembly line operation, under the temperature condition of 55 - 65 °C, control the drying of the board surface for 1.5 - 2.5 h, and it can directly enter the next process.

[0035] A special epoxy AB adhesive for back net is used for back net bonding and fixing.

[0036] In summary, the beneficial effects of the present invention are:

[0037] Through the interpenetrating network structure formed by carboxyl-terminated nitrile rubber and epoxy resin in the present invention, the peel strength of the adhesive reaches 15 - 20 N / mm (GB / T2791), which is more than 50% higher than that of traditional epoxy adhesives (less than 12 N / mm), and can effectively resist the peel stress between the back net material and the matrix, ensuring the stability and reliability of the structure.

[0038] The synergistic effect of the nano-SiO2 and silane coupling agent in the present invention enables the adhesive to have a tensile shear strength retention rate of greater than or equal to 90% (GB / T 7124) after continuous testing for 500 hours in an environment of 85°C / 85% RH, significantly improving the performance stability of the adhesive in a humid and hot environment and extending the service life of the back net structure.

[0039] The design of the dual-curing system adopted in the present invention greatly shortens the curing time of the adhesive. The normal-temperature curing time is shortened from more than 24 hours in the traditional case to 2 - 4 hours, and the heat-curing only takes 30 minutes, meeting the strict requirements of industrial assembly line production for production efficiency and effectively reducing the production cost and time cost.

[0040] The elongation at break of the adhesive in the present invention is greater than 15%, having good flexibility and impact resistance; the long-term use temperature is less than or equal to 150°C, and the short-term heat resistance can reach 200°C, being able to meet the usage requirements under extreme working conditions and providing a reliable guarantee for the application of the back net material in different fields. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] Embodiment 1:

[0043] A preparation method of an epoxy AB adhesive special for a back net includes the following steps:

[0044] Step S1, preparation of component A: Add 50% of bisphenol A epoxy resin, 15% of carboxyl-terminated nitrile rubber, 8% of nano-SiO2, 2% of KH-550, 8% of diluent, and 7% of plasticizer into a reaction kettle in precise proportions, and continuously stir at a stirring speed of 300 - 500 r / min at a temperature of 60 - 80°C for 30 - 60 minutes until a uniform and transparent system is formed;

[0045] Step S2, preparation of component B: Add 60% of modified aliphatic amine curing agent, 15% of polyetheramine, 2% of 2,4,6-tris(dimethylaminomethyl)phenol, and 23% of nano-calcium carbonate into a high-speed disperser in sequence, and disperse at a high speed of 1000 - 1500 r / min at normal temperature for 15 - 20 minutes to ensure that each component is fully mixed to form a uniform paste;

[0046] Step S3, Mixing and Curing: Weigh components A and B accurately according to the pre-determined weight ratio, mix them, and stir well by mechanical stirring or manual stirring. Then quickly apply the adhesive to the bonding surfaces of the back net material and the matrix material, apply appropriate pressure, and select to cure at room temperature for 2 - 4 hours or heat to 60°C and cure for 30 minutes according to actual production requirements.

[0047] Example 2:

[0048] A preparation method of a special epoxy AB adhesive for back nets, comprising the following steps:

[0049] Step S1, Preparation of Component A: Add 45% of bisphenol A epoxy resin, 20% of carboxyl-terminated nitrile rubber, 10% of nano-SiO2, 3% of silane coupling agent, 10% of reactive diluent, and 7% of plasticizer into the reaction kettle according to precise ratios. Under the temperature condition of 60 - 80°C, continuously stir at a stirring speed of 300 - 500 r / min for 30 - 60 minutes until a uniform and transparent system is formed;

[0050] Step S2, Preparation of Component B: Add 55% of modified aliphatic amine curing agent, 20% of polyetheramine, 3% of accelerator, and 22% of nano-calcium carbonate into the high-speed disperser in sequence. Under normal temperature environment, disperse at a high speed of 1000 - 1500 r / min for 15 - 20 minutes to ensure that all components are fully mixed to form a uniform paste;

[0051] Step S3, Mixing and Curing: Weigh components A and B accurately according to the pre-determined weight ratio, mix them, and stir well by mechanical stirring or manual stirring. Then quickly apply the adhesive to the bonding surfaces of the back net material and the matrix material, apply appropriate pressure, and select to cure at room temperature for 2 - 4 hours or heat to 60°C and cure for 30 minutes according to actual production requirements.

[0052] Example 3:

[0053] A preparation method of a special epoxy AB adhesive for back nets, comprising the following steps:

[0054] Step S1, Preparation of Component A: Add 40% of epoxy resin, 20% of carboxyl-terminated nitrile rubber, 10% of nano-SiO2, 3% of KH-550, 10% of benzyl glycidyl ether, and 7% of dioctyl phthalate into the reaction kettle according to precise ratios. Under the temperature condition of 60 - 80°C, continuously stir at a stirring speed of 300 - 500 r / min for 30 - 60 minutes until a uniform and transparent system is formed;

[0055] Step S2, Preparation of Component B: Add 50% of T-31 curing agent, 20% of D-230 polyetheramine, 3% of accelerator, and 27% of nano-CaCO3 into a high-speed disperser in sequence. Under normal temperature environment, disperse at a high speed of 1000 - 1500 r / min for 15 - 20 min to ensure that each component is fully mixed to form a uniform paste;

[0056] Step S3, Mixing and Curing: Weigh Components A and B accurately according to the pre-determined weight ratio, mix them, and stir well by mechanical stirring or manual stirring. Then quickly coat the adhesive on the bonding surfaces of the back net material and the matrix material, apply appropriate pressure, and select normal temperature curing for 2 - 4 hours or heating to 60°C for curing for 30 min according to actual production requirements.

[0057] Example 4:

[0058] A preparation method of a special epoxy AB adhesive for back net, comprising the following steps:

[0059] Step S1, Preparation of Component A: Add 60% of E-51 epoxy resin, 10% of carboxyl-terminated nitrile rubber, 5% of nano-SiO2, 1% of KH-550, 5% of benzyl glycidyl ether, and 4% of dioctyl phthalate into a reaction kettle according to precise proportions. Under the temperature condition of 60 - 80°C, stir continuously at a stirring speed of 300 - 500 r / min for 30 - 60 min until a uniform and transparent system is formed;

[0060] Step S2, Preparation of Component B: Add 70% of T-31 curing agent, 10% of D-230 polyetheramine, 1% of accelerator, and 19% of nano-CaCO3 into a high-speed disperser in sequence. Under normal temperature environment, disperse at a high speed of 1000 - 1500 r / min for 15 - 20 min to ensure that each component is fully mixed to form a uniform paste;

[0061] Step S3, Mixing and Curing: Weigh Components A and B accurately according to the pre-determined weight ratio, mix them, and stir well by mechanical stirring or manual stirring. Then quickly coat the adhesive on the bonding surfaces of the back net material and the matrix material, apply appropriate pressure, and select normal temperature curing for 2 - 4 hours or heating to 60°C for curing for 30 min according to actual production requirements.

[0062] Example 5 (Comparative Example)

[0063] Formulation:

[0064] Commercially available epoxy AB glue (Comparative Document CN202411525431.X)

[0065] Without adding carboxyl-terminated nitrile rubber and nano-SiO2

[0066] Performance indicators:

[0067] Tensile shear strength: 18 MPa

[0068] Peel strength: 10 N / mm

[0069] Resistance to damp heat aging (500 h): Strength retention rate 55%

[0070] Curing time: 24 hours at room temperature

[0071] Performance testing methods

[0072] 1. Tensile shear strength test (GB / T7124~2008)

[0073] Specimen preparation: Coat the adhesive on an aluminum alloy sheet (25 mm×50 mm×2 mm), with an overlap area of 12.5 mm×25 mm, and test after curing.

[0074] Testing equipment: Universal testing machine (accuracy ±1%), tensile rate 2 mm / min.

[0075] Environmental conditions: 23℃±2℃, humidity 50%±5%.

[0076] 2. Peel strength test (GB / T2791~1995)

[0077] Specimen preparation: Coat the adhesive on a glass fiber mesh and an aluminum plate (100 mm×25 mm×2 mm), and test after curing.

[0078] Testing equipment: Universal testing machine, peel rate 100 mm / min.

[0079] Result calculation: Take the average value of 5 specimens, unit N / mm.

[0080] 3. Resistance to damp heat aging test (GB / T2573~2008)

[0081] Environmental conditions: 85℃ / 85%RH constant temperature and humidity chamber, for 500 hours continuously.

[0082] Performance evaluation: Strength retention rate before and after aging = (strength after aging / initial strength)×100%.

[0083] 4. Curing time test

[0084] Room temperature curing: Use a probe to detect the surface curing degree every 30 min after applying the glue, and record the complete curing time.

[0085] Heating curing: Place the glued specimen in an oven at 60℃ and record the curing time.

[0086] 5. Tensile Elongation at Break Test (GB / T 2567~2008)

[0087] Specimen shape: dumbbell-shaped, gauge length 50 mm.

[0088] Testing equipment: universal testing machine, tensile rate 50 mm / min.

[0089] Result calculation: Tensile elongation at break = (gauge length at break ~ initial gauge length) / initial gauge length × 100%.

[0090] 6. Heat Resistance Test

[0091] Testing method: Place the cured adhesive specimen in an oven, heat it to 150°C at a rate of 5°C / min, keep it at this temperature for 2 hours, and then observe whether it softens.

[0092] Case of Comparative Analysis

[0093] Case 1: Example 1 of the present invention vs. Comparative Document CN202411525431.X

[0094] Performance IndexExample 1 of the Present InventionComparative DocumentPerformance Improvement of Adhesive

[0095] Tensile Shear Strength25 MPa18 MPa+38.9%

[0096] Peel Strength18 N / mm10 N / mm+80%

[0097] Retention Rate of Damp Heat Aging92%55%+67.3%

[0098] Normal Temperature Curing Time3 hours24 hours~87.5%

[0099] Case 2: Example 2 of the present invention vs. Commercially Available Epoxy AB Adhesive

[0100] Performance IndexExample 2 of the Present InventionCommercially Available Epoxy AB AdhesivePerformance Improvement

[0101] Tensile Elongation at Break16%4%+300%

[0102] Short-Term Heat Resistance200°CNo softening120°CSoftening+66.7%

[0103] Peel Strength20 N / mm12 N / mm+66.7%

[0104] Data Analysis and Conclusion

[0105] Effect of Rubber Toughening: When the content of carboxyl-terminated nitrile rubber increases from 10% to 20%, the peel strength increases from 16 N / mm to 20 N / mm (Example 4 vs. Example 2), and the tensile elongation at break increases from 15% to 18%, verifying the toughening effect of the interpenetrating network structure.

[0106] Nano synergistic effect: When the content of nano-SiO2 increases from 5% to 10%, the retention rate of heat and humidity aging increases from 88% to 92% (Example 3 vs Example 1), indicating that the active interface layer effectively inhibits interface damage in a humid and hot environment.

[0107] Advantages of the curing system: The dual-curing system shortens the room-temperature curing time to 2 - 4 hours, and only 20 - 35 minutes for heat curing, far exceeding the 24-hour curing requirement of traditional epoxy adhesives.

[0108] Specific steps of the performance testing method for the special epoxy AB adhesive for the back net:

[0109] 1. Tensile shear strength test (in accordance with GB / T7124 - 2008)

[0110] 1.1 Specimen preparation

[0111] Material preparation: Prepare aluminum alloy sheets with dimensions of 25mm × 50mm × 2mm. The surface of the aluminum alloy sheets should be smooth, free of oil stains and oxide layers. They can be polished with sandpaper and cleaned thoroughly with organic solvents such as acetone.

[0112] Gluing operation: Thoroughly mix Component A and Component B of the special epoxy AB adhesive for the back net according to the specified weight ratio (such as 1:1 - 3:1). Use tools such as a spatula to evenly coat the adhesive on the bonding part of the aluminum alloy sheet. Control the coating thickness within an appropriate range (such as 0.1 - 0.2mm) to ensure that the lap joint area is 12.5mm × 25mm.

[0113] Curing treatment: Cure the glued aluminum alloy sheets according to the specified curing conditions (such as 2 - 4 hours at room temperature or 30 minutes at 60°C, etc.). During the curing process, ensure that the specimens are not affected by external forces and environmental factors.

[0114] 1.2 Testing equipment and operation

[0115] Equipment selection: Use a universal testing machine, requiring the accuracy of the testing machine to reach ±1% and be able to accurately measure the tensile force and displacement.

[0116] Install the specimen: Install the cured specimen on the fixture of the universal testing machine, ensuring that the specimen is firmly installed and the force application direction is consistent with the tensile direction of the testing machine.

[0117] Set parameters: Set the tensile rate to 2mm / min, and start the testing machine to conduct the tensile test.

[0118] 1.3 Data recording and processing

[0119] Record data: During the test, the testing machine automatically records the force and displacement data during the stretching process until the specimen fails, and records the maximum tensile force.

[0120] Calculate strength: According to the maximum tensile force and the lap area, calculate the tensile shear strength. Tensile shear strength (MPa) = maximum tensile force (N) / lap area (mm 2 ). At least 5 specimens should be tested for each formula, and the average value is taken as the final result.

[0121] 2. Peel strength test (according to GB / T2791~1995)

[0122] 2.1 Specimen preparation

[0123] Material preparation: Prepare fiberglass mesh and aluminum plate. The size of the aluminum plate is 100mm×25mm×2mm, and the surface of the aluminum plate is cleaned.

[0124] Gluing operation: After mixing components A and B of the adhesive evenly, coat them evenly on the bonding parts of the fiberglass mesh and the aluminum plate. After gluing, fit the two together and apply a certain pressure to expel air bubbles to ensure good bonding.

[0125] Curing treatment: Cure according to the specified curing conditions. After curing, place the specimen for a period of time to make its performance stable.

[0126] 2.2 Testing equipment and operation

[0127] Equipment selection: Use a universal testing machine for the peel test.

[0128] Install the specimen: Fix one end of the specimen on the fixture of the testing machine and fix the other end in a suitable way to ensure that the specimen is evenly stressed during the peeling process.

[0129] Set parameters: Set the peel rate to 100mm / min, and start the testing machine for the peel test.

[0130] 2.3 Data recording and processing

[0131] Record data: Record the change data of the peel force with the peel length during the test, and take the average peel force in the stable peeling stage.

[0132] Calculate strength: Peel strength (N / mm) = average peel force (N) / specimen width (mm). Similarly, at least 5 specimens should be tested and the average value is taken.

[0133] 3. Damp heat aging resistance test (according to GB / T2573~2008)

[0134] 3.1 Specimen preparation

[0135] Prepare specimens with the same specifications and processes as those for the tensile shear strength test, and the number is determined according to the test requirements (such as 5 - 10).

[0136] 3.2 Test environment setting

[0137] Set the thermo - hygrostat to an environmental condition of 85°C / 85% RH. After the environment inside the box stabilizes, place the specimens into the box.

[0138] 3.3 Aging test process

[0139] Let the specimens continuously stay in the thermo - hygrostat for 500 hours. During this period, regularly observe the appearance changes of the specimens (such as whether there are bubbles, cracks, etc.).

[0140] 3.4 Performance evaluation

[0141] After the aging test is completed, take out the specimens from the box and let them stand at room temperature for a period of time to balance the temperature. Then, conduct the tensile shear strength test on the aged specimens according to the tensile shear strength test method, and calculate the retention rate of the tensile shear strength before and after aging. The strength retention rate (%) = (strength after aging / initial strength) × 100%.

[0142] 4. Curing time test

[0143] 4.1 Normal - temperature curing time test

[0144] Gluing operation: After mixing components A and B evenly, apply a layer of adhesive on a flat test plate, keeping the gluing thickness and area consistent.

[0145] Detection process: Start timing from the moment of gluing. Every 30 minutes, gently touch the surface of the adhesive with a probe. When the probe no longer adheres to the glue and the surface of the adhesive has a certain hardness, record the time at this moment as the normal - temperature curing time.

[0146] 4.2 Heat - curing time test

[0147] Gluing operation: Similarly, apply the mixed adhesive on the test plate.

[0148] Heat treatment: Quickly place the test plate coated with the adhesive into an oven at 60°C and start timing. Open the oven every certain period of time (such as 5 minutes) to observe the curing situation of the adhesive. When the adhesive is completely cured (such as no stickiness when touched by hand and the hardness reaches the requirement), record the heat - curing time.

[0149] 5. Elongation at break test (in accordance with GB / T2567 - 2008)

[0150] 5.1 Specimen preparation

[0151] Mold Preparation: Use a dumbbell-shaped mold. The dimensions of the mold should meet the standard requirements, and the gauge length is 50 mm.

[0152] Casting and Molding: Slowly pour the mixed adhesive into the mold to avoid generating air bubbles, and then cure it according to the specified curing conditions.

[0153] Demolding Treatment: After curing, carefully remove the specimen from the mold, check whether there are defects on the surface of the specimen. If there are defects, it should be prepared again.

[0154] 5.2 Testing Equipment and Operations

[0155] Equipment Selection: Use a universal testing machine for tensile testing.

[0156] Install the Specimen: Install the dumbbell-shaped specimen on the fixture of the testing machine, ensure that the clamping force of the fixture on the specimen is appropriate, does not damage the specimen, and can ensure that the specimen is evenly stressed during the tensile process.

[0157] Set Parameters: Set the tensile rate to 50 mm / min, start the testing machine for tensile testing until the specimen breaks.

[0158] 5.3 Data Recording and Processing

[0159] Record Data: Record the gauge length when the specimen breaks.

[0160] Calculate Elongation at Break: Elongation at break (%) = (gauge length at break - initial gauge length) / initial gauge length × 100%. Test at least 5 specimens and take the average value.

[0161] 6. Heat Resistance Test

[0162] 6.1 Specimen Preparation

[0163] Prepare specimens with the same specifications as those for the tensile shear strength test, with the number of specimens being 3 - 5.

[0164] 6.2 Test Procedure

[0165] Put the specimens into the oven, raise the oven temperature to 150°C at a heating rate of 5°C / min, and then keep the temperature constant for 2 hours.

[0166] 6.3 Result Observation

[0167] After 2 hours, turn off the oven. After the specimens cool down to room temperature, take them out and observe whether there are phenomena such as softening and deformation of the specimens to judge the heat resistance performance of the adhesive. Specific Example 1:

[0169] A method for using a special epoxy AB adhesive for back mesh, characterized by comprising the following steps:

[0170] Step 1, Mixing: Weigh components A and B in equal proportion of 1:1 and mix them. Use mechanical stirring or manual stirring to fully stir evenly to obtain mixture A;

[0171] Step 2, Diluting: Add a specified amount of water to mixture C and stir evenly;

[0172] Step 3, Adding Cement: Add a specified amount of 425 white cement (for white class boards) or cement (for grey class boards), stir evenly, and then prepare mixture D;

[0173] Step 4, Gluing and Curing: After the back net glue is mixed, apply mixture D on the bonding surfaces of the back net material and the substrate material to fill and repair the gaps of the stone. Under normal circumstances, the board can be taken in 2 hours. It is recommended to enter the next process after 3 days. In the case of assembly line operation, under the condition of temperature 55 - 65 °C, control the board surface to be dried for 1.5 - 2.5 h, and it can directly enter the next process.

[0174]

[0175] The parts not elaborated in detail in the present invention belong to the well-known technology of those skilled in the art.

[0176] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A special epoxy AB adhesive for back nets, characterized in that, The epoxy AB adhesive, the epoxy A adhesive is composed of the following components according to the weight ratio: Component A: Bisphenol A epoxy resin 40-60%; Carboxyl-terminated nitrile rubber 10-20%; Nano-SiO2 5-10%; Silane coupling agent 1-3%; Reactive diluent 5-10%; Plasticizer 3-8%; Component B: Modified aliphatic amine curing agent 50-70%; Polyetheramine 10-20%; Accelerator 1-3%; Nano calcium carbonate 10-20%.

2. The epoxy AB adhesive special for the back net according to claim 1, wherein: The particle size of the nano-SiO2 is 50 to 100 nm, and the specific surface area is 200 to 300 m 2 / g.

3. The epoxy AB adhesive for the special back net according to claim 1, characterized in that: The silane coupling agent is one or several of KH-550, methyltrichlorosilane, aminosilane, vinylsilane, epoxysilane and allyltrimethoxysilane.

4. The epoxy AB adhesive for back net as claimed in claim 1, wherein: The reactive diluent is one or several of benzyl glycidyl ether, n-butyl glycidyl ether, phenyl glycidyl ether, cresol glycidyl ether, polyethylene glycol diglycidyl ether, benzyl alcohol, tributyl phosphate.

5. The epoxy AB adhesive for special use on the back net according to claim 1, characterized in that: The plasticizer is one or several of dioctyl phthalate, dimethyl phthalate, diisononyl phthalate, diisodecyl phthalate.

6. The epoxy AB adhesive for special use on the back net according to claim 1, wherein: The modified aliphatic amine curing agent is T-31.

7. The epoxy AB adhesive for back net as claimed in claim 1, wherein: The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

8. The preparation method of a special epoxy AB adhesive for a back net according to any one of claims 1 to 7, characterized in that It includes the following steps: Step S1, Preparation of Component A: Add epoxy resin, carboxyl-terminated nitrile rubber, nano-SiO2, KH-550, diluent and plasticizer into the reaction kettle according to the precise ratio, and under the temperature condition of 60-80 °C, continuously stir at a stirring speed of 300-500 r / min for 30-60 min until a uniform and transparent system is formed; Step S2, Preparation of Component B: Add the curing agent, polyetheramine, accelerator and nano calcium carbonate into the high-speed disperser in sequence, and under the normal temperature environment, disperse at a high speed of 1000-1500 r / min for 15-20 min to ensure that each component is fully mixed to form a uniform paste.

9. The method for using a special epoxy AB adhesive for a back net according to claim 8, characterized in that, It includes the following steps: Step 1, Mixing: Weigh Components A and B in equal proportion of 1:1 and mix them, and fully stir them evenly by mechanical stirring or manual stirring to obtain Mixture A; Step 2, Dilution: Add a specified amount of water to Mixture C and stir evenly; Step 3, Adding Cement: Add a specified amount of 425 white cement or cement, stir evenly, and prepare Mixture D; Step 4, Glue Coating and Curing: After the back net glue is mixed, apply Mixture D on the bonding surfaces of the back net material and the substrate material to fill and repair the gaps of the stone. Under normal circumstances, the board can be taken in 2 hours. It is recommended to enter the next process after 3 days. Under the condition of assembly line operation, under the temperature condition of 55-65 °C, control the drying of the board surface for 1.5-2.5 h, and it can directly enter the next process.

10. A special epoxy AB adhesive for back net according to any one of claims 1-9 is applied to back net bonding and fixing.

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