Low-temperature high-toughness acrylate adhesive and preparation method thereof

Abstract

The invention discloses a low-temperature high-toughness acrylate adhesive and a preparation method thereof, and relates to the technical field of acrylate adhesives. The low-temperature high-toughness acrylate adhesive comprises a component A and a component B. The component A comprises 40-50 parts of a modified graft copolymer, 30-40 parts of a modified elastomer, 5-10 parts of an antioxidant, 5-10 parts of an initiator, 0.1-0.3 part of an accelerant, 5-10 parts of a flexibilizer, 5-8 parts of a stabilizer, 0.3-0.5 part of a defoaming agent and 0.3-0.5 part of a coupling agent. The component B comprises 50-70 parts of peroxide, 30-40 parts of a plasticizer and 2-4 parts of a thickening agent; the dosage ratio of the component A to the component B is 10: 1. The acrylate adhesive with a modified formula is more resistant to low temperature, has high polymerization degree and a plurality of branched chains, forms a spatial network structure through mutual crosslinking, and has higher toughness.

Description

Technical Field

[0001] The present invention relates to the technical field of acrylate adhesives, and particularly relates to a low-temperature and high-toughness acrylate adhesive and a preparation method thereof. Background Art

[0002] Acrylate adhesives are polymer materials based on acrylic acid or methacrylic acid. In terms of the core principle, acrylate adhesives achieve the bonding effect through intermolecular van der Waals forces, hydrogen bonds, and partial chemical cross-linking. Its history can be traced back to the mid-20th century. Initially, these materials were mainly used to improve the performance of traditional adhesives, such as enhancing the bonding strength and weather resistance. With the continuous optimization of the formulation and production process, acrylate adhesives have been significantly improved in terms of bonding performance and chemical resistance.

[0003] Existing acrylate adhesives can bond materials such as steel, iron, aluminum, titanium, stainless steel, plastics, glass, and ceramics, and are applicable to the manufacturing, installation, and repair of automobiles, motorcycles, mechatronic engineering, chemical pipelines, handicrafts, and household appliances, and can provide relatively high shear strength, peel strength, and chemical resistance. Despite many advantages, acrylate adhesives also have some limitations. For example, their bonding performance is poor under extreme temperature conditions, they lack toughness, and are prone to failure, which limits their application in certain specific fields. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention provides a low-temperature and high-toughness acrylate adhesive and a preparation method thereof, which greatly improve the toughness and low-temperature adhesiveness of the cured colloid.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A low-temperature and high-toughness acrylate adhesive, comprising component A and component B. Component A includes 40-50 parts of a modified graft copolymer, 30-40 parts of a modified elastomer, 5-10 parts of an antioxidant, 5-10 parts of an initiator, 0.1-0.3 parts of an accelerator, 5-10 parts of a toughening agent, 5-8 parts of a stabilizer, 0.3-0.5 parts of an antifoaming agent, and 0.3-0.5 parts of a coupling agent; Component B includes 50-70 parts of a peroxide, 30-40 parts of a plasticizer, and 2-4 parts of a thickener; The dosage ratio of component A to component B is A∶B = 10∶1.

[0006] Furthermore, for the modified graft copolymer, the modified graft copolymer comprises the following raw materials: 10-30 parts of butadiene-styrene rubber particles, 50-80 parts of methyl methacrylate monomer, 20-40 parts of toluene, 5-10 parts of tris(2,4-di-tert-butylphenyl) phosphite, 1-3 parts of azobisisobutyronitrile, 4-8 parts of chitosan quaternary ammonium salt, 3-5 parts of carbon fiber, and 3-8 parts of nano-titanium dioxide.

[0007] Furthermore, the modified graft copolymer is prepared by the following steps: A1. Dissolve butadiene-styrene rubber particles and methyl methacrylate monomer in toluene solvent, then add tris(2,4-di-tert-butylphenyl) phosphite, stir at a speed of 300 - 600 r / min for 20 - 60 minutes, and then add azobisisobutyronitrile, continue to stir at a speed of 300 - 600 r / min for 20 - 60 minutes to generate a graft copolymer;

[0008] A2. Add chitosan quaternary ammonium salt to the above solution and stir at a stirring speed of 300 - 500 r / min for 15 - 30 minutes;

[0009] A3. Heat the above mixture to 100 - 200 °C, add carbon fiber, and stir at a speed of 400 - 600 r / min for 10 - 30 minutes;

[0010] A4. Add nano-titanium dioxide to the above mixture, stir at a speed of 400 - 600 r / min for 20 - 60 minutes, then pour it into a reaction kettle, seal the reaction kettle and put it into a heating box to raise the temperature to 90 - 120 °C; A5. Grind the product into particles with a size of 10 - 50 μm, wash it, and dry it at 50 - 70 °C for 10 - 16 h to obtain the required modified graft copolymer.

[0011] Furthermore, the modified elastomer comprises the following raw materials: 80 - 160 parts of ethylene-propylene-diene monomer rubber, 4 - 10 parts of dimethyl maleate, 1 - 5 parts of benzoyl peroxide, 5 - 10 parts of paraffin oil, 5 - 10 parts of EPDM sulfonate ionomer, 50 - 80 parts of deionized water, 10 - 20 parts of quaternary ammonium salt, 10 - 20 parts of hexafluoropropylene, 10 - 20 parts of propylene monomer, 30 - 80 parts of methyl acrylate, 1 - 5 parts of benzoyl peroxide, 20 - 70 parts of toluene, 5 - 10 parts of benzophenone solution; Furthermore, the specific preparation steps of the modified elastomer are as follows: B1. Take half of the ethylene-propylene-diene monomer rubber and add it to a twin-screw extruder, heat it to 140 - 180 °C, then sequentially add dimethyl maleate, benzoyl peroxide and paraffin oil, and mix and stir at a rotation speed of 600 - 1000 r / min for 10 - 30 minutes to obtain a graft copolymer; B2. Mix the graft copolymer and ethylene-propylene-diene monomer rubber at room temperature and stir at a stirring speed of 400 - 700 r / min for 10 - 30 minutes to obtain a high-toughness elastomer; B3. The obtained high-toughness elastomer and EPDM sulfonate ionomer are melt-blended in a screw extruder at 150 - 200 °C to obtain Substance A; B4. Add deionized water to the polymerization reactor, slowly add the emulsifier under the stirring condition of 400 - 600 r / min, then add hexafluoropropene and propylene monomers to the reactor, and introduce nitrogen gas, controlling the reaction temperature at 50 - 80 °C; Mix the obtained product with Substance A and stir at a stirring speed of 400 - 500 r / min for 10 - 30 minutes to obtain Substance B;

[0012] B5. Take methyl acrylate and benzoyl peroxide and add them to a three-necked flask equipped with a nitrogen protection device, then add toluene and stir at room temperature for 30 - 60 minutes, then heat the system, control the temperature at 60 - 80 °C, and continuously introduce nitrogen gas, and stir and react for 3 - 5 hours to obtain an acrylate polymer; Then add the polymer to the benzophenone solution, continuously introduce nitrogen gas and irradiate the reaction system with ultraviolet light, and turn off the light source when the viscosity of the reaction system significantly increases to obtain a photocuring material; Add the photocuring material to Substance B and stir at a stirring speed of 400 - 500 r / min for 20 - 40 minutes to obtain the required modified elastomer.

[0013] Further, the antioxidant is tris(2,4-di-tert-butylphenyl) phosphite; the initiator is benzoyl peroxide; the accelerator is N,N-dimethyl-p-toluidine.

[0014] Further, the toughening agent is one or more of liquid polysulfide rubber, liquid polybutadiene rubber, liquid nitrile rubber and styrene-butadiene rubber.

[0015] Further, the stabilizer is composed of a low-carbon fatty amine and a metal chelating agent mixed in a mass ratio of 1:1; the defoaming agent is methyl silicone oil.

[0016] Further, the coupling agent is one of KH-550 and KH-560.

[0017] Further, the peroxide is one or more of phthaloyl peroxide, lauroyl peroxide and cumene hydroperoxide.

[0018] Further, the plasticizer is one or more of dimethyl phthalate, diethyl phthalate, dibutyl phthalate and dioctyl phthalate.

[0019] Further, the thickening agent is polymethyl methacrylate.

[0020] A low-temperature high-toughness acrylate adhesive is prepared by the following steps: C1. Prepare Component A. In a three-necked flask equipped with a stirring device, a thermometer, and a condenser, sequentially add the modified graft copolymer, toughening agent, and antioxidant. Start the stirring device, control the stirring speed at 600 - 800 r / min, slowly heat up to 50 - 60 °C, maintain this temperature for 30 - 60 minutes, then quickly add the modified elastomer, initiator, and accelerator to the three-necked flask. At the same time, increase the stirring speed to 400 - 500 r / min. After stirring for 30 - 60 minutes, add the stabilizer, defoaming agent, and coupling agent. Control the reaction temperature at 60 - 80 °C and continue the reaction for 2 - 4 hours. Stop stirring and pour it into an open container while it is hot to obtain Component A. C2. Prepare Component B. Sequentially add the peroxide, plasticizer, and thickener into the dispersion kettle, and stir at a speed of 300 - 400 r / min for 30 - 60 minutes to obtain Component B. C3. Finally, add Component A and Component B into the dispersion kettle simultaneously, and stir at a stirring speed of 300 - 400 r / min for 30 - 60 minutes to obtain the acrylate adhesive. The dosage ratio of Component A to Component B is A∶B = 10∶1.

[0021] The present invention provides a low-temperature and high-toughness acrylate adhesive and its preparation method, which has the following beneficial effects: 1. This low-temperature and high-toughness acrylate adhesive uses methyl methacrylate as the basic resin and adds butadiene-styrene rubber to form a graft copolymer, which has good low-temperature resistance. The prepared adhesive will not easily fail in extremely cold environments. At the same time, it also adds a modified elastomer formed by dimethyl maleate and ethylene-propylene diene monomer to synergistically toughen the adhesive and improve the toughness of the adhesive.

[0022] 2. In the modified graft copolymer, first use azobisisobutyronitrile to initiate the copolymerization reaction of butadiene-styrene rubber particles and methyl methacrylate monomers. The active chain of methyl methacrylate will undergo a graft reaction with the active sites on the molecular chain of butadiene-styrene rubber to generate a graft copolymer, improving the low-temperature resistance of the substance. Then add chitosan quaternary ammonium salt. Its positively charged quaternary ammonium group can strongly attract the negative charge on the surface of bacteria and has a destructive effect on the cell membrane of bacteria, providing antibacterial properties for the adhesive. Then add carbon fiber. For methyl methacrylate-butadiene-styrene graft copolymer, its polar part will preferentially adsorb on the active sites on the surface of carbon fiber, enhancing the mechanical properties and thermal stability of the substance. Finally, add nano-titanium dioxide. Nano-titanium dioxide can absorb and scatter ultraviolet light, reduce the damage of ultraviolet light to the adhesive, and effectively extend the service life of the adhesive.

[0023] 3. In the modified elastomer, first add ethylene propylene diene monomer (EPDM) rubber and dimethyl maleate. Through the action of initiator benzoyl peroxide, free radicals are generated at the tertiary carbon positions on the molecular chain of EPDM rubber, and an addition reaction occurs between the free radicals and dimethyl maleate, thereby grafting dimethyl maleate onto the molecular chain of EPDM rubber. The product has good flexibility and elastic recovery ability. Then mix it with EPDM rubber to obtain a high-toughness elastomer. Next, add EPDM sulfonate ionomer and hexafluoropropylene and propylene monomers. The prepared adhesive has thermal stability, weather resistance, and corrosion resistance. Then add a photocuring material to enable the adhesive to achieve rapid curing and improve production efficiency.

[0024] 4. The acrylate adhesive with the modified formula is more resistant to low temperatures, has a high degree of polymerization and multiple branches, and cross-links with each other to form a three-dimensional network structure, making it more ductile. When subjected to impact, it can absorb a large amount of energy through the stretching and deformation of the molecular chain, thereby effectively preventing the bonded object from being damaged under impact load. Specific embodiments

[0025] 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0026] Example 1 A low-temperature and high-toughness acrylate adhesive, including component A and component B. Component A includes 40 parts of modified graft copolymer, 30 parts of modified elastomer, 5 parts of antioxidant, 5 parts of initiator, 0.1 part of accelerator, 5 parts of toughening agent, 5 parts of stabilizer, 0.3 part of defoaming agent, and 0.3 part of coupling agent; Component B includes 50 parts of peroxide, 30 parts of plasticizer, and 2 parts of thickener; the dosage ratio of component A to component B is A∶B = 10∶1.

[0027] The production process of the low-temperature and high-toughness acrylate adhesive is as follows: C1. Prepare component A. In a three-necked flask equipped with a stirring device, a thermometer, and a condenser, sequentially add the modified graft copolymer, liquid polysulfide rubber, and tris(2,4-di-tert-butylphenyl) phosphite. Start the stirring device, control the stirring speed at 600 r / min, slowly heat up to 50 °C, and maintain this temperature for 30 minutes. Then quickly add the modified elastomer, benzoyl peroxide, and N,N-dimethyl-p-toluidine to the three-necked flask, and at the same time increase the stirring speed to 400 r / min. After stirring for 30 minutes, add the stabilizer, methyl silicone oil, and KH-550. Control the reaction temperature at 60 °C and continue the reaction for 2 hours. Stop stirring and pour it into an open container while it is hot to obtain component A. C2. Prepare Component B. Add phthaloyl peroxide, dimethyl phthalate and polymethyl methacrylate into the dispersion kettle in sequence, with a stirring speed of 300 r / min, and stir for 30 minutes to obtain Component B. C3. Finally, add Component A and Component B into the dispersion kettle simultaneously, and stir at a speed of 300 r / min for 30 minutes to obtain the acrylate adhesive. The dosage ratio of Component A to Component B is A:B = 10:1.

[0028] The modified graft copolymer contains the following raw materials: 10 parts of butadiene-styrene rubber particles, 50 parts of methyl methacrylate monomer, 20 parts of toluene, 5 parts of tris(2,4-di-tert-butylphenyl) phosphite, 1 part of azobisisobutyronitrile, 4 parts of chitosan quaternary ammonium salt, 3 parts of carbon fiber, and 3 parts of nano-titanium dioxide.

[0029] The modified graft copolymer is prepared through the following steps: A1. Dissolve the butadiene-styrene rubber particles and methyl methacrylate monomer in toluene solvent, then add tris(2,4-di-tert-butylphenyl) phosphite, stir at a speed of 300 r / min for 20 minutes, and then add azobisisobutyronitrile, and continue to stir at a speed of 300 r / min for 20 minutes to generate a graft copolymer. A2. Add chitosan quaternary ammonium salt into the above solution, and stir at a stirring speed of 300 r / min for 15 minutes. A3. Heat the above mixture to 100 °C, add carbon fiber, and stir at a speed of 400 r / min for 10 minutes. A4. Add nano-titanium dioxide into the above mixture, stir at a speed of 400 r / min for 20 minutes, then pour it into the reaction kettle, seal the reaction kettle and put it into the heating box to raise the temperature to 90 °C. A5. Grind the product into particles with a size of 10 μm, wash it, and dry it at 50 °C for 10 h to obtain the required modified graft copolymer.

[0030] The modified elastomer contains the following raw materials: 80 parts of ethylene-propylene-diene monomer rubber, 4 parts of dimethyl maleate, 1 part of benzoyl peroxide, 5 parts of paraffin oil, 5 parts of EPDM sulfonate ionomer, 50 parts of deionized water, 10 parts of quaternary ammonium salt, 10 parts of hexafluoropropylene, 10 parts of propylene monomer, 30 parts of methyl acrylate, 1 part of benzoyl peroxide, 20 parts of toluene, and 5 parts of benzophenone solution. The modified elastomer is prepared through the following steps: B1. Take half of the ethylene-propylene-diene monomer rubber and add it to the twin-screw extruder, heat it to 140 °C, and then add dimethyl maleate, benzoyl peroxide and paraffin oil in sequence, and mix and stir at a speed of 600 r / min for 10 minutes to obtain a graft copolymer. B2. Mix the graft copolymer with ethylene-propylene-diene monomer rubber at room temperature, stir at a speed of 400 r / min for 10 minutes to obtain a high-toughness elastomer; B3. Melt-blend the obtained high-toughness elastomer with EPDM sulfonate ionomer in a screw extruder at 150 °C to obtain Substance A; B4. Add deionized water to the polymerization reactor, slowly add quaternary ammonium salt under the stirring condition of 400 r / min, then add hexafluoropropylene and propylene monomers to the reactor, and introduce nitrogen gas, controlling the reaction temperature at 50 °C; Mix the obtained product with Substance A and stir at a speed of 400 r / min for 10 minutes to obtain Substance B; B5. Take methyl acrylate and benzoyl peroxide and add them to a three-necked flask equipped with a nitrogen protection device, then add toluene and stir at room temperature for 30 minutes, then heat the system, control the temperature at 60 °C, and continuously introduce nitrogen gas, stir and react for 3 hours to obtain an acrylate polymer; Then add the polymer to a benzophenone solution, continuously introduce nitrogen gas and irradiate the reaction system with ultraviolet light, and turn off the light source when the viscosity of the reaction system increases significantly to obtain a photocurable material; Add the photocurable material to Substance B and stir at a speed of 400 r / min for 20 minutes to obtain the required modified elastomer.

[0031] Example 2 A low-temperature high-toughness acrylate adhesive, comprising Component A and Component B. Component A includes 50 parts of modified graft copolymer, 40 parts of modified elastomer, 10 parts of antioxidant, 10 parts of initiator, 0.3 parts of accelerator, 10 parts of toughening agent, 8 parts of stabilizer, 0.5 parts of defoaming agent and 0.5 parts of coupling agent; Component B includes 70 parts of peroxide, 40 parts of plasticizer, and 4 parts of thickener; The dosage ratio of Component A to Component B is A∶B = 10∶1.

[0032] The specific production process of this low-temperature high-toughness acrylate adhesive is as follows: C1. Prepare Component A. In a three-necked flask equipped with a stirring device, a thermometer and a condenser, sequentially add the modified graft copolymer, liquid polybutadiene rubber, tris(2,4-di-tert-butylphenyl) phosphite, turn on the stirring device, control the stirring speed at 800 r / min, slowly heat up to 60 °C, maintain this temperature for 60 minutes, then quickly add the modified elastomer, benzoyl peroxide, N,N-dimethyl-p-toluidine to the three-necked flask, and at the same time increase the stirring speed to 500 r / min, stir for 60 minutes and then add the stabilizer, methyl silicone oil and KH-560, control the reaction temperature at 80 °C, continuously react for 4 hours, stop stirring, and pour it into an open container while it is hot to obtain Component A; C2. Prepare Component B. Add lauroyl peroxide, diethyl phthalate, and polymethyl methacrylate into the dispersion kettle in sequence. The stirring speed is 400 r / min, and stir for 60 minutes to obtain Component B. C3. Finally, add Component A and Component B into the dispersion kettle simultaneously, and stir at a speed of 400 r / min for 60 minutes to obtain the acrylate adhesive. The dosage ratio of Component A to Component B is A∶B = 10∶1.

[0033] The modified graft copolymer comprises the following raw materials: 30 parts of butadiene-styrene rubber particles, 80 parts of methyl methacrylate monomer, 40 parts of toluene, 10 parts of tris(2,4-di-tert-butylphenyl) phosphite, 3 parts of azobisisobutyronitrile, 8 parts of chitosan quaternary ammonium salt, 5 parts of carbon fiber, and 8 parts of nano titanium dioxide.

[0034] The modified graft copolymer is prepared through the following steps: A1. Dissolve the butadiene-styrene rubber particles and methyl methacrylate monomer in toluene solvent, then add tris(2,4-di-tert-butylphenyl) phosphite, stir at a speed of 600 r / min for 60 minutes, and then add azobisisobutyronitrile, and continue to stir at a speed of 600 r / min for 60 minutes to generate a graft copolymer. A2. Add the chitosan quaternary ammonium salt into the above solution, and stir at a stirring speed of 500 r / min for 30 minutes. A3. Heat the above mixture to 200 °C, add carbon fiber, and stir at a speed of 600 r / min for 30 minutes. A4. Add nano titanium dioxide into the above mixture, stir at a speed of 600 r / min for 60 minutes, then pour it into the reaction kettle, seal the reaction kettle, and put it into the heating box to raise the temperature to 120 °C. A5. Grind the product into particles with a size of 50 μm, wash it, and dry it at 70 °C for 16 h to obtain the required modified graft copolymer.

[0035] The modified elastomer comprises the following raw materials: 160 parts of ethylene-propylene-diene monomer rubber, 10 parts of dimethyl maleate, 5 parts of benzoyl peroxide, 10 parts of paraffin oil, 10 parts of EPDM sulfonate ionomer, 80 parts of deionized water, 20 parts of quaternary ammonium salt, 20 parts of hexafluoropropylene, 20 parts of propylene monomer, 80 parts of methyl acrylate, 5 parts of benzoyl peroxide, 70 parts of toluene, and 10 parts of benzophenone solution. The modified elastomer is prepared through the following steps: B1. Take half of the ethylene-propylene-diene monomer rubber and add it to the twin-screw extruder, heat it to 180 °C, then add dimethyl maleate, benzoyl peroxide, and paraffin oil in sequence, and mix and stir at a speed of 1000 r / min for 30 minutes to obtain a graft copolymer. B2. Mix the graft copolymer with the ethylene-propylene-diene monomer rubber at room temperature, and stir at a stirring speed of 700 r / min for 30 minutes to obtain a high-toughness elastomer; B3. Melt-blend the obtained high-toughness elastomer with the EPDM sulfonate ionomer in a screw extruder at 200 °C to obtain Substance A; B4. Add deionized water to the polymerization reactor, slowly add the quaternary ammonium salt under the stirring condition of 600 r / min, then add hexafluoropropylene and propylene monomers to the reactor, and introduce nitrogen gas, controlling the reaction temperature at 80 °C; Mix the obtained product with Substance A, and stir at a stirring speed of 500 r / min for 30 minutes to obtain Substance B; B5. Take methyl acrylate and benzoyl peroxide and add them to a three-necked flask equipped with a nitrogen protection device, then add toluene and stir at room temperature for 60 minutes, then heat the system, control the temperature at 80 °C, and continuously introduce nitrogen gas, and stir and react for 5 hours to obtain an acrylate polymer; Then add the polymer to the benzophenone solution, continuously introduce nitrogen gas and irradiate the reaction system with ultraviolet light, and turn off the light source when the viscosity of the reaction system increases significantly to obtain a photocurable material; Add the photocurable material to Substance B, and stir at a stirring speed of 500 r / min for 40 minutes to obtain the required modified elastomer.

[0036] Example 3 A low-temperature and high-toughness acrylate adhesive, comprising Component A and Component B. Component A includes 45 parts of a modified graft copolymer, 35 parts of a modified elastomer, 7 parts of an antioxidant, 8 parts of an initiator, 0.2 parts of an accelerator, 7 parts of a toughening agent, 6 parts of a stabilizer, 0.4 parts of an antifoaming agent, and 0.4 parts of a coupling agent; Component B includes 60 parts of a peroxide, 35 parts of a plasticizer, and 3 parts of a thickener; The dosage ratio of Component A to Component B is A∶B = 10∶1.

[0037] The specific production process of this low-temperature and high-toughness acrylate adhesive is as follows: C1. Prepare Component A. In a three-necked flask equipped with a stirring device, a thermometer, and a condenser, sequentially add the modified graft copolymer, liquid nitrile rubber, and tris(2,4-di-tert-butylphenyl) phosphite, turn on the stirring device, control the stirring speed at 700 r / min, slowly heat up to 55 °C, and maintain this temperature for 45 minutes. Then quickly add the modified elastomer, benzoyl peroxide, and N,N-dimethyl-p-benzidine to the three-necked flask, and at the same time increase the stirring speed to 450 r / min. After stirring for 45 minutes, add the stabilizer, methyl silicone oil, and KH-560, control the reaction temperature at 70 °C, and continue to react for 3 hours. Stop stirring and pour it into an open container while it is hot to obtain Component A; C2. Prepare Component B. Add cumene hydroperoxide, dibutyl phthalate, and polymethyl methacrylate into the dispersion kettle in sequence. The stirring speed is 350 r / min, and stir for 45 minutes to obtain Component B. C3. Finally, add Component A and Component B into the dispersion kettle simultaneously, and stir at a stirring speed of 350 r / min for 45 minutes to obtain the acrylate adhesive. The dosage ratio of Component A to Component B is A∶B = 10∶1.

[0038] The modified graft copolymer contains the following raw materials: 20 parts of butadiene-styrene rubber particles, 65 parts of methyl methacrylate monomer, 30 parts of toluene, 7 parts of tris(2,4-di-tert-butylphenyl) phosphite, 2 parts of azobisisobutyronitrile, 6 parts of chitosan quaternary ammonium salt, 4 parts of carbon fiber, and 5 parts of nano titanium dioxide. The modified graft copolymer is prepared through the following steps: A1. Dissolve the butadiene-styrene rubber particles and methyl methacrylate monomer in the toluene solvent, then add tris(2,4-di-tert-butylphenyl) phosphite, stir at a speed of 450 r / min for 40 minutes, and then add azobisisobutyronitrile, and continue to stir at a speed of 450 r / min for 40 minutes to generate a graft copolymer. A2. Add chitosan quaternary ammonium salt to the above solution and stir at a stirring speed of 400 r / min for 22 minutes. A3. Heat the above mixture to 150 °C, add carbon fiber, and stir at a speed of 500 r / min for 20 minutes. A4. Add nano titanium dioxide to the above mixture, stir at a speed of 500 r / min for 40 minutes, then pour it into the reaction kettle, seal the reaction kettle, and place it in a heating box to raise the temperature to 105 °C. A5. Grind the product into particles with a size of 30 μm, wash it, and dry it at 60 °C for 13 h to obtain the required modified graft copolymer.

[0039] The modified elastomer contains the following raw materials: 120 parts of ethylene-propylene-diene monomer rubber, 7 parts of dimethyl maleate, 3 parts of benzoyl peroxide, 7 parts of paraffin oil, 7 parts of EPDM sulfonate ionomer, 65 parts of deionized water, 15 parts of quaternary ammonium salt, 15 parts of hexafluoropropylene, 15 parts of propylene monomer, 55 parts of methyl acrylate, 3 parts of benzoyl peroxide, 45 parts of toluene, and 7 parts of benzophenone solution. The modified elastomer is prepared through the following steps: B1. Take half of the ethylene-propylene-diene monomer rubber and add it to the twin-screw extruder, heat it to 160 °C, then add dimethyl maleate, benzoyl peroxide, and paraffin oil in sequence, and mix and stir at a rotation speed of 800 r / min for 20 minutes to obtain a graft copolymer. B2. Mix the graft copolymer and the binary ethylene-propylene rubber at room temperature, stir at a speed of 550 r / min for 20 minutes to obtain a high-toughness elastomer; B3. Melt-blend the obtained high-toughness elastomer and the EPDM sulfonate ionomer in a screw extruder at 175 °C to obtain Substance A; B4. Add deionized water to the polymerization reactor, slowly add the quaternary ammonium salt under stirring at 500 r / min, then add hexafluoropropylene and propylene monomers to the reactor, and introduce nitrogen gas, controlling the reaction temperature at 65 °C; Mix the obtained product with Substance A and stir at a speed of 450 r / min for 20 minutes to obtain Substance B; B5. Take methyl acrylate and benzoyl peroxide and add them to a three-necked flask equipped with a nitrogen protection device, then add toluene and stir at room temperature for 45 minutes, then heat the system, control the temperature at 70 °C, and continuously introduce nitrogen gas, and stir and react for 4 hours to obtain an acrylate polymer; Then add the polymer to the benzophenone solution, continuously introduce nitrogen gas and irradiate the reaction system with ultraviolet light, and turn off the light source when the viscosity of the reaction system increases significantly to obtain a photocurable material; Add the photocurable material to Substance B and stir at a speed of 450 r / min for 30 minutes to obtain the required modified elastomer.

[0040] Comparative Example 1 This comparative example is the same as Example 3 except that the graft copolymer is not added.

[0041] Comparative Example 2 This comparative example is the same as Example 3 except that the modified elastomer is not added.

[0042] Performance Test Perform the following performance tests on a low-temperature high-toughness acrylate adhesive prepared in Examples 1-3 and Comparative Examples 1-3. The test results are shown in the following table: Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tensile strength (MPa) 18.6 19.1 19.6 19.4 17.1 Initial shear strength (MPa) 24.5 25.3 25.8 25.4 21.6 Shear strength after corrosion aging (MPa) 16.8 17.6 17.9 17.8 14.3 Impact strength 25 25 26 25 22 Curing time at 0°C (h) 16.5 16.1 15.4 17.6 15.8 Antibacterial rate (%) 97% 98% 98% 50% 98% As can be seen from the tabular test data, when the addition amounts of various substances and the operating conditions in Example 3 are at the intermediate values, compared with the addition amounts of substances and the operating conditions in Example 1 and Example 2, the tensile strength, initial shear strength, shear strength after corrosion aging, and impact strength of the acrylate adhesive prepared are all improved, the curing time at 0 °C is reduced, and the antibacterial rate is stronger than that in Example 1 and the same as that in Example 2. It can be seen that the adhesive prepared in Example 3 is already the optimal formulation. In Comparative Example 1, the modified graft copolymer was not added, and compared with Example 3, it can be seen that the curing time at 0 °C was prolonged and the antibacterial rate was significantly reduced. In Comparative Example 2, the modified elastomer was not added, and compared with Example 3, its tensile strength, initial shear strength, shear strength after corrosion aging, and impact strength were all reduced. Therefore, the acrylate adhesive added with the modified graft copolymer and the modified elastomer has excellent low-temperature resistance, toughness, impact strength, and antibacterial properties.

[0043] The above content is only an example and illustration of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution. As long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A low-temperature, high-toughness acrylic adhesive, characterized in that: The invention comprises component A and component B, wherein the component A comprises 40-50 parts of a modified graft copolymer, 30-40 parts of a modified elastomer, 5-10 parts of an antioxidant, 5-10 parts of an initiator, 0.1-0.3 parts of an accelerator, 5-10 parts of a toughening agent, 5-8 parts of a stabilizer, 0.3-0.5 parts of a defoaming agent and 0.3-0.5 parts of a coupling agent; the component B comprises 50-70 parts of a peroxide, 30-40 parts of a plasticizer and 2-4 parts of a thickener; and the dosage ratio of the component A to the component B is A:B=10:

1.

2. The low-temperature, high-toughness acrylic adhesive according to claim 1, characterized in that: The modified graft copolymer comprises the following raw materials: 10-30 parts of butadiene-styrene rubber particles, 50-80 parts of methyl methacrylate monomer, 20-40 parts of toluene, 5-10 parts of tris(2,4-di-tert-butylphenyl)phosphite, 1-3 parts of azobisisobutyronitrile, 4-8 parts of chitosan quaternary ammonium salt, 3-5 parts of carbon fiber, and 3-8 parts of nano titanium dioxide; The modified graft copolymer is prepared by the following steps: A1. Dissolve butadiene-styrene rubber particles and methyl methacrylate monomer in toluene solvent, add tris(2,4-di-tert-butylphenyl)phosphite, stir at 300-600 r / min for 20-60 minutes, then add azobisisobutyronitrile, and continue stirring at 300-600 r / min for 20-60 minutes to generate a graft copolymer; A2. Add chitosan quaternary ammonium salt to the above solution and stir at a stirring speed of 300-500 r / min for 15-30 minutes; A3. Heat the above mixed solution to 100-200°C, add carbon fiber, and stir at 400-600r / min for 10-30 minutes; A4. Add nano titanium dioxide to the above mixed solution, stir at 400-600 r / min for 20-60 minutes, then pour into the reactor, seal the reactor and place it in a heating box to heat to 90-120°C; A5. Grind the product into particles with a size of 10-50 μm, wash it, and dry it at 50-70° C. for 10-16 hours to obtain the desired modified graft copolymer.

3. The low-temperature, high-toughness acrylic adhesive according to claim 1, characterized in that: The modified elastomer comprises the following raw materials: 80-160 parts of EPDM rubber, 4-10 parts of dimethyl maleate, 1-5 parts of benzoyl peroxide, 5-10 parts of paraffin oil, 5-10 parts of EPDM sulfonate ionomer, 50-80 parts of deionized water, 10-20 parts of quaternary ammonium salt, 10-20 parts of hexafluoropropylene, 10-20 parts of propylene monomer, 30-80 parts of methyl acrylate, 1-5 parts of benzoyl peroxide, 20-70 parts of toluene, and 5-10 parts of benzophenone solution; The modified elastomer is prepared by the following steps: B1, take half of the EPDM rubber and add it into a twin-screw extruder, heat it to 140-180°C, then add dimethyl maleate, benzoyl peroxide and paraffin oil in sequence, mix and stir at a speed of 600-1000 r / min for 10-30 minutes to obtain a graft copolymer; B2, mixing the graft copolymer with EPDM rubber at room temperature, stirring at a stirring speed of 400-700 r / min for 10-30 minutes to obtain a high-toughness elastomer; B3, melt-blending the obtained high-toughness elastomer with EPDM sulfonate ionomer in a screw extruder at 150-200° C. to obtain substance A; B4, adding deionized water to the polymerization reactor, slowly adding quaternary ammonium salt under stirring condition of 400-600r / min, then adding hexafluoropropylene and propylene monomer into the reactor, and introducing nitrogen, controlling the reaction temperature at 50-80°C; mixing the obtained product with substance A, stirring at a stirring speed of 400-500r / min for 10-30 minutes to obtain substance B; B5. Take methyl acrylate and benzoyl peroxide and add them to a three-necked flask containing a nitrogen protection device, then add toluene and stir at room temperature for 30-60 minutes, then heat the system, control the temperature at 60-80°C, and continue to introduce nitrogen, and stir the reaction for 3-5 hours to obtain an acrylate polymer; then add the polymer to a benzophenone solution, continue to introduce nitrogen and irradiate the reaction system with ultraviolet light, and turn off the light source when the viscosity of the reaction system increases significantly to obtain a photocurable material; add the photocurable material to substance B, and stir at a stirring speed of 400-500 r / min for 20-40 minutes to obtain the desired modified elastomer.

4. The low-temperature, high-toughness acrylic adhesive according to claim 1, characterized in that: The antioxidant is tris(2,4-di-tert-butylphenyl)phosphite; and the initiator is benzoyl peroxide.

5. The low-temperature high-toughness acrylic adhesive according to claim 1, characterized in that: The accelerator is N,N-dimethyl-p-tolidine.

6. The low-temperature high-toughness acrylic adhesive according to claim 1, characterized in that: The toughening agent is one or more of liquid polysulfide rubber, liquid polybutadiene rubber, liquid nitrile rubber and styrene-butadiene rubber.

7. The low-temperature high-toughness acrylic adhesive according to claim 1, characterized in that: The stabilizer is composed of a mixture of low-carbon fatty amine and metal chelating agent in a mass ratio of 1:1; and the defoaming agent is methyl silicone oil.

8. The low-temperature high-toughness acrylic adhesive according to claim 1, characterized in that: The coupling agent is one of KH-550 and KH-560.

9. The low-temperature, high-toughness acrylic adhesive according to claim 1, characterized in that: The peroxide is one or more of phthaloyl peroxide, lauroyl peroxide, and cumene hydroperoxide; the plasticizer is one or more of dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and dioctyl phthalate; and the thickener is polymethyl methacrylate.

10. A method for preparing a low-temperature high-toughness acrylic adhesive, characterized in that: The following steps are involved: C1. Prepare component A. In a three-necked flask equipped with a stirring device, a thermometer, and a condenser, add the modified graft copolymer, the toughening agent, and the antioxidant in sequence, turn on the stirring device, control the stirring speed at 600-800 r / min, slowly raise the temperature to 50-60°C, maintain this temperature for 30-60 minutes, then quickly add the modified elastomer, initiator, and accelerator to the three-necked flask, and increase the stirring speed to 400-500 r / min. After stirring for 30-60 minutes, add the stabilizer, defoamer, and coupling agent, control the reaction temperature at 60-80°C, continue the reaction for 2-4 hours, stop stirring, and pour into an open container while hot to obtain component A; C2. Prepare component B. Add peroxide, plasticizer and thickener into the dispersion kettle in sequence. Stir at a speed of 300-400 r / min. Stir for 30-60 minutes to obtain component B. C3. Finally, add component A and component B into a dispersion kettle at the same time, stir at a stirring speed of 300-400 r / min for 30-60 minutes to obtain the acrylic adhesive, wherein the usage ratio of component A to component B is A:B=10:1.

Images