Modified epoxy resin adhesive as well as preparation method and application thereof

Abstract

The invention relates to the technical field of mucilage glue, in particular to modified epoxy resin mucilage glue and a preparation method and application thereof.Bisphenol A epoxy resin, a curing agent, a defoaming agent, a coupling agent, a diluent, auxiliaries and filler are mixed to obtain the single-component epoxy resin mucilage glue which is high in curing rate and high in adhesion. The curing agent is obtained by mixing a curing agent A and a curing agent B. The curing agent A prepared by taking phenolic aldehyde amine as a core material and isocyanate as a wall material can crack and release the curing agent at a relatively high temperature so as to be cured with epoxy resin; in the curing agent B capable of being cured at medium and low temperatures, the core material 2, 4, 6-tri (dimethylaminomethyl) phenol is wrapped by glyceryl tristearate and is combined with the biochar due to the adsorption effect, the stability of the curing agent B in the adhesive can be further enhanced, and the biochar can also be used as a filler to enhance the interface adhesive force of the epoxy resin, so that the adhesive strength of the epoxy resin is improved. Wide application prospects are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of viscose, in particular to a modified epoxy resin viscose and a preparation method and application thereof. Background Art

[0002] Epoxy resin is a high molecular polymer with the molecular formula (C 11 H 12 Epoxy (O3)n refers to a class of polymers containing two or more epoxy groups in their molecules. It is an amorphous, viscous liquid that becomes plastic upon heating and has no distinct melting point. It softens upon heating, gradually melting and becoming sticky. It is insoluble in water and does not harden on its own, making it of little use in its own right. It is a condensation product of epichlorohydrin and bisphenol A or a polyol. Due to the chemical activity of the epoxy group, it can be ring-opened with a variety of compounds containing active hydrogen, which can then be cured and cross-linked to form a network structure, making it a thermosetting resin.

[0003] Epoxy resin curing agent is an additive that chemically reacts with epoxy resin to form a three-dimensional network polymer, wrapping the composite material aggregate in the network and turning the linear resin into a tough solid. When a certain amount of curing agent is added to the epoxy resin, it gradually solidifies and is used as a binder.

[0004] As an important general-purpose adhesive, epoxy resin adhesive is widely used in automobile manufacturing, clean energy, electronic devices and other fields due to its excellent mechanical properties, thermal stability, chemical stability and insulation properties.

[0005] Since its emergence around 1950, epoxy resin adhesives have experienced rapid development in performance, variety, and applications. Epoxy resins and their curing systems possess unique and exceptional properties. The continuous emergence of new epoxy resins, curing agents, and additives has made them a key adhesive class with superior performance, a wide variety, and broad adaptability. They are widely used in bonding polar materials such as metal, glass, cement, wood, and plastics, earning them the reputation of a universal adhesive.

[0006] In the prior art, for example, patent document CN115260962B discloses a room temperature curing fast epoxy resin adhesive and its preparation method, which is composed of component A and component B; wherein component A is prepared from the following raw materials in parts by weight: 40-50 parts of bisphenol A epoxy resin, 5-10 parts of homemade modified epoxy resin, 10-15 parts of nano rubber toughening agent, 25-35 parts of barium sulfate, 1-3 parts of KH560, and 0.5-3 parts of fumed silica; component B is prepared from the following raw materials in parts by weight: Composition: 50-65 parts of modified amine curing agent, 1-8 parts of bisphenol A, 35-45 parts of barium sulfate, 0.5-3 parts of KH550, and 0.5-3 parts of fumed silica; in this invention, the homemade modified amine curing agent gives the epoxy adhesive a higher cross-linking density and better chemical stability, and cures at a stable speed at room temperature, but this two-component adhesive must be packaged and transported separately, and after the adhesive solution is prepared, its service life is limited, which limits the applicability of the two-component adhesive to a certain extent.

[0007] Patent technology document CN111171285B discloses a kind of epoxy resin curing agent microcapsule with polyurethane as shell material and its preparation method. In this invention, diisocyanate monomer is reacted with small molecule diol, macromolecular polyol and hydrophilic polyol to synthesize isocyanate-terminated polyurethane prepolymer, then epoxy resin curing agent is dispersed in the prepolymer, water is added to make polyurethane prepolymer aqueous dispersion containing curing agent, and finally epoxy resin curing agent microcapsule with polyurethane as shell material is prepared by interfacial polymerization with water-soluble amine. In this invention, a curing agent is synthesized, which can effectively isolate the curing agent and epoxy resin and react during storage at room temperature, which is conducive to transportation and packaging. However, this curing agent can only release the curing agent at high temperature. While rapidly heating to increase the curing rate, it is easy to cause increased internal stress in the material and uneven heating, which in turn leads to a decrease in the bonding strength of the epoxy resin adhesive.

[0008] Therefore, according to the above-mentioned related technologies, there is an urgent need to develop a modified epoxy resin adhesive and its preparation method and application. Summary of the Invention

[0009] In view of this, the object of the present invention is to provide a modified epoxy resin adhesive and a preparation method and application thereof, so as to provide a modified epoxy resin adhesive with strong adhesion and fast curing rate.

[0010] Based on the above objectives, the present invention provides a modified epoxy resin adhesive and a preparation method and application thereof.

[0011] A modified epoxy resin adhesive comprises the following raw materials in parts by weight:

[0012] Bisphenol A epoxy resin 41-50 parts; curing agent 28-36 parts; defoaming agent 0.5-1 parts; coupling agent 2-4 parts; diluent 4-8 parts; auxiliary agent 0.3-0.5 parts; filler 7-12 parts;

[0013] The curing agent is obtained by mixing curing agent A and curing agent B in a mass ratio of 6-9:1.4-1.8;

[0014] The curing agent A is prepared from phenolic amine and 4,4,-dicyclohexylmethane diisocyanate;

[0015] The curing agent B is prepared from 2,4,6-tris(dimethylaminomethyl)phenol, tristearate and biochar;

[0016] The auxiliary agent is obtained by mixing auxiliary agent A and auxiliary agent B in a mass ratio of 4-8:0.3-0.5;

[0017] The auxiliary agent A is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole;

[0018] The auxiliary agent B is a few-layer molybdenum disulfide.

[0019] Preferably, the preparation method of the curing agent A is as follows:

[0020] Step A1. Add liquid paraffin and 3% by mass of Span85 to a beaker, stir evenly, then add phenalkamine and continue stirring to obtain Emulsion A.

[0021] Step A2. Add 4,4-dicyclohexylmethane diisocyanate and liquid paraffin to a beaker, stir for 10-15 minutes, and then add dropwise to emulsion A. React at room temperature for 50-65 minutes. After heating for reaction, wash with cyclohexane and air-dry naturally to obtain curing agent A.

[0022] Preferably, the mass ratio of liquid paraffin, Span85 and phenalkamine in step A1 is 47-55:1.3-1.6:4.5-5.2;

[0023] The mass ratio of 4,4,-dicyclohexylmethane diisocyanate, liquid paraffin and emulsion A in step A2 is 4-7:10-18:25-32;

[0024] The temperature during the heating reaction is 45-53° C. and the time is 4.5-5.5 hours.

[0025] Preferably, the preparation method of the curing agent B is as follows:

[0026] Step B1. After cleaning, crushing, and drying the sugarcane straw, carbonizing it at 450-500°C, 5g of the sugarcane straw was soaked in 20-25g of a 40% KOH solution, stirred for 12-13 hours, allowed to stand for 20-24 hours, and then dried at 110-120°C for 48-50 hours. After cooling, the sugarcane straw was washed twice with a 1 mol / L hydrochloric acid solution and then with deionized water, and then dried at 60-70°C for 3-4 hours to obtain biochar.

[0027] Step B2. Add a surfactant to deionized water, stir well, then add n-octanol defoamer, heat and stir to obtain a mixed solution A;

[0028] Step B3. Mixing 2,4,6-tris(dimethylaminomethyl)phenol and glyceryl tristearate and heating to obtain a mixture B;

[0029] Step B4. Add mixed solution B to mixed solution A, heat and stir to obtain a dispersion, then pour ice water into the dispersion, filter, wash with deionized water, and dry, then add to biochar, stir for 8-13 minutes, and ultrasonically treat for 2-5 minutes to obtain curing agent B.

[0030] Preferably, the mass ratio of deionized water, surfactant and defoaming agent in step B2 is 30-40:0.72-0.8:0.1-0.2;

[0031] The surfactant is any one of sodium dodecylbenzenesulfonate and Tween;

[0032] The temperature during the heating and stirring is 55-62°C and the time is 25-35 minutes;

[0033] The mass ratio of 2,4,6-tris(dimethylaminomethyl)phenol to tristearin in step B3 is 2.3-3.7:1;

[0034] The heating temperature is 82-90° C. and the heating time is 40-55 minutes.

[0035] Preferably, the mass ratio of mixed solution B, mixed solution A, ice water and biochar is 1.6-2.5:130-140:18-22:8-13;

[0036] The temperature during the heating and stirring is 60-68°C and the time is 6-9 minutes;

[0037] The drying temperature is 55-60° C. and the drying time is 30-40 minutes.

[0038] Preferably, the preparation method of the auxiliary agent B is as follows:

[0039] Molybdenum disulfide was added to a 95% ethanol solution by mass, stirred evenly, and then poured into a jet cavitation device. The parameters were set to obtain a suspension, and the suspension was dried at 75-85°C to obtain a few-layer molybdenum disulfide.

[0040] The molybdenum disulfide and ethanol solution are used in a ratio of 1-1.5 g to 100-150 mL.

[0041] The pressure in the parameters is 150000-170000 KPa, and the temperature of the circulating cooling water bath is 8-13°C.

[0042] Preferably, the diluent is at least one of benzyl glycidyl ether, neodecanoic acid glycidyl ester, and phenyl glycidyl ether;

[0043] The filler is any one of calcium carbonate and silicon powder;

[0044] The defoamer is defoamer BYK066N;

[0045] The coupling agent is coupling agent Z-6040.

[0046] A method for preparing a modified epoxy resin adhesive comprises the following steps:

[0047] Mix bisphenol A epoxy resin, curing agent, defoaming agent, coupling agent, diluent, additives and filler, stir evenly, and perform vacuum degassing to obtain modified epoxy resin adhesive;

[0048] The stirring rate during the degassing is 200-260 r / min and the temperature is 30-35°C.

[0049] The invention discloses an application of a modified epoxy resin adhesive, wherein the modified epoxy resin adhesive is used as an adhesive in the field of construction.

[0050] Beneficial effects of the present invention:

[0051] The present invention provides a modified epoxy resin adhesive, a preparation method thereof, and an application thereof. The present invention obtains a one-component epoxy resin adhesive with a fast curing rate and strong adhesion by mixing bisphenol A epoxy resin, a curing agent, a defoaming agent, a coupling agent, a diluent, an auxiliary agent, and a filler. The curing agent in the present invention is obtained by mixing curing agent A and curing agent B. Curing agent A, which is prepared with phenalkamine as a core material and isocyanate as a wall material, can break and release the curing agent at a relatively high temperature, thereby curing with the epoxy resin. In curing agent B, which can be cured at medium and low temperatures, the core material 2,4,6-tris(dimethylaminomethyl)phenol is wrapped in tristearate and combined with biochar due to adsorption, which can further enhance the stability of curing agent B in the adhesive. The biochar can also be used as a filler to enhance the interfacial adhesion of the epoxy resin.

[0052] In the present invention, the 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole in the auxiliary agent can effectively absorb ultraviolet rays and convert them into heat energy, promote the cracking and release of the curing agent, and reduce ultraviolet damage to the material by absorbing ultraviolet radiation, thereby reducing the generation of cracks inside the material; the few-layer molybdenum disulfide in the auxiliary agent can also absorb photon energy and convert it into heat energy, and can further improve the mechanical properties of the epoxy resin adhesive. The two synergistically enhance the effect and work together with the curing agent to improve the curing rate while avoiding the generation of large thermal stress and uneven mixing inside the epoxy resin caused by rapid temperature increase, thereby affecting the curing effect. Compared with the existing technology, the present invention has broad application prospects. DETAILED DESCRIPTION

[0053] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0054] The sources and properties of some of the raw materials used in the present invention are as follows:

[0055] 4,4-Dicyclohexylmethane diisocyanate was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Span85 was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; liquid paraffin was purchased from Foshan Xilong Chemical Co., Ltd.; phenolamine T31 was purchased from Guangzhou Huayue Viscose Chemical Co., Ltd.; 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole was purchased from Hubei Weideli Chemical Technology Co., Ltd.; coupling agent Z-6040 was purchased from Dow Corning; bisphenol A epoxy resin E51 was purchased from Jiangsu Yangnong Jinhu Chemical.

[0056] Example 1: A method for preparing a modified epoxy resin adhesive, comprising the following steps:

[0057] S1. Add 47g of liquid paraffin and 1.3g of 3% Span85 to a beaker, stir evenly, then add 4.5g of phenalkamine and continue stirring to obtain emulsion A;

[0058] S2. 4 g of 4,4-dicyclohexylmethane diisocyanate and 10 g of liquid paraffin were added to a beaker, stirred for 10 min, and then added dropwise to 25 g of emulsion A. The mixture was reacted at room temperature for 50 min, then heated to 45 ° C and reacted for 4.5 h. The mixture was washed with cyclohexane and air-dried to obtain curing agent A.

[0059] S3. After washing, crushing, and drying the sugarcane straw, carbonizing it at 450°C, 5g of the sugarcane straw was immersed in 20g of a 40% KOH solution, stirred for 12h, allowed to stand for 20h, and then dried at 110°C for 48h. After cooling, the mixture was washed twice with 1mol / L hydrochloric acid solution and then with deionized water, and then dried at 60°C for 3h to obtain biochar.

[0060] S4. To 30g of deionized water was added 0.72g of sodium dodecylbenzenesulfonate, stirred, and then 0.1g of n-octanol defoamer was added, heated to 55 ° C and stirred for 25min to obtain a mixed solution A;

[0061] S5. Mix 2.3 g of 2,4,6-tris(dimethylaminomethyl)phenol and 1 g of glyceryl tristearate and heat to 82°C for 40 min to obtain a mixture B;

[0062] S6. 1.6 g of mixed solution B was added to 130 g of mixed solution A, and the mixture was heated and stirred at 60°C for 6 min to obtain a dispersion. 18 g of ice water was then poured into the dispersion, filtered, washed with deionized water, and dried at 55°C for 30 min. The dispersion was then added to 8 g of biochar, stirred for 8 min, and ultrasonically treated for 2 min to obtain curing agent B.

[0063] S7. 1 g of molybdenum disulfide was added to 100 mL of a 95% ethanol solution by mass, stirred, and poured into a jet cavitation device at a pressure of 150,000 kPa and a circulating cooling water bath at 8°C to obtain a suspension, which was then dried at 75°C to obtain a few-layer molybdenum disulfide.

[0064] S8 6g of curing agent A and 1.4g of curing agent B were mixed to obtain a curing agent; then 4g2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole was mixed with 0.3g of a few-layer molybdenum disulfide to obtain an additive;

[0065] S9.41g bisphenol A epoxy resin, 28g curing agent, 0.5g defoaming agent BYK066N, 2g coupling agent Z-6040, 4g benzyl glycidyl ether, 0.3g auxiliary agent, and 7-12g calcium carbonate are mixed, stirred evenly, and vacuum degassed at a temperature of 30°C and a stirring rate of 200 r / min to obtain a modified epoxy resin adhesive.

[0066] Example 2: A method for preparing a modified epoxy resin adhesive, comprising the following steps:

[0067] S1. Add 50g of liquid paraffin and 1.4g of 3% Span85 to a beaker, stir evenly, then add 4.8g of phenalkamine and continue stirring to obtain emulsion A;

[0068] S2. 5 g of 4,4-dicyclohexylmethane diisocyanate and 13 g of liquid paraffin were added to a beaker, stirred for 12 min, and then added dropwise to 28 g of emulsion A. The mixture was reacted at room temperature for 55 min, then heated to 48 ° C and reacted for 5 h. The mixture was washed with cyclohexane and air-dried to obtain curing agent A.

[0069] S3. After washing, crushing, and drying the sugarcane straw, carbonizing it at 470°C, 5g of the sugarcane straw was immersed in 22g of a 40% KOH solution, stirred for 12.5h, allowed to stand for 22h, and then dried at 115°C for 49h. After cooling, the mixture was washed twice with 1mol / L hydrochloric acid solution and then with deionized water, and then dried at 63°C for 3.5h to obtain biochar.

[0070] S4. To 33g of deionized water was added 0.75g of sodium dodecylbenzenesulfonate, stirred, and then 0.14g of n-octanol defoamer was added, heated to 58 ° C and stirred for 28min to obtain a mixed solution A;

[0071] S5. Mix 2.7 g of 2,4,6-tris(dimethylaminomethyl)phenol and 1 g of glyceryl tristearate and heat to 85°C for 45 min to obtain a mixture B;

[0072] S6. 1.9 g of mixed solution B was added to 134 g of mixed solution A, and the mixture was heated and stirred at 63°C for 7 min to obtain a dispersion. 20 g of ice water was then poured into the dispersion, filtered, washed with deionized water, and dried at 57°C for 35 min. The dispersion was then added to 10 g of biochar, stirred for 10 min, and ultrasonically treated for 3 min to obtain curing agent B.

[0073] S7. 1.2 g of molybdenum disulfide was added to 120 mL of a 95% ethanol solution by mass, stirred, and poured into a jet cavitation device at a pressure of 160,000 kPa and a circulating cooling water bath temperature of 10 ° C to obtain a suspension, which was dried at 78 ° C to obtain a few layers of molybdenum disulfide;

[0074] S8 7g of curing agent A and 1.6g of curing agent B were mixed to obtain a curing agent; then 5g2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole was mixed with 0.4g of a few-layer molybdenum disulfide to obtain an additive;

[0075] S9.44g bisphenol A epoxy resin, 31g curing agent, 0.7g defoaming agent BYK066N, 3g coupling agent Z-6040, 5g benzyl glycidyl ether, 0.4g auxiliary agent, and 9g calcium carbonate were mixed and stirred evenly. Then, vacuum degassing was performed at a temperature of 32°C and a stirring rate of 220r / min to obtain a modified epoxy resin adhesive.

[0076] Example 3: A method for preparing a modified epoxy resin adhesive, comprising the following steps:

[0077] S1. Add 52g of liquid paraffin and 1.5g of 3% Span85 to a beaker, stir well, then add 5g of phenalkamine and continue stirring to obtain emulsion A;

[0078] S2. 6 g of 4,4-dicyclohexylmethane diisocyanate and 16 g of liquid paraffin were added to a beaker, stirred for 14 min, and then added dropwise to 30 g of emulsion A. The mixture was reacted at room temperature for 60 min, then heated to 50 ° C and reacted for 5 h. The mixture was washed with cyclohexane and air-dried to obtain curing agent A.

[0079] S3. After washing, crushing, and drying the sugarcane straw, carbonizing it at 480°C, 5g of the sugarcane straw was immersed in 24g of a 40% KOH solution, stirred for 13h, allowed to stand for 23h, and then dried at 120°C for 50h. After cooling, the mixture was washed twice with 1mol / L hydrochloric acid solution and then with deionized water, and then dried at 68°C for 3.5h to obtain biochar.

[0080] S4. To 37g of deionized water was added 0.77g of sodium dodecylbenzenesulfonate, stirred, and then 0.17g of n-octanol defoamer was added, heated to 60 ° C and stirred for 32min to obtain a mixed solution A;

[0081] S5. Mix 3.2 g of 2,4,6-tris(dimethylaminomethyl)phenol and 1 g of glyceryl tristearate and heat to 88°C for 50 min to obtain a mixture B;

[0082] S6. Add 2.2 g of mixed solution B to 137 g of mixed solution A, heat and stir at 66°C for 8 min to obtain a dispersion. Then, pour 21 g of ice water into the dispersion, filter, wash with deionized water, and dry at 58°C for 38 min. Then, add 11 g of biochar, stir for 11 min, and ultrasonicate for 4 min to obtain curing agent B.

[0083] S7. 1.4 g of molybdenum disulfide was added to 140 mL of a 95% ethanol solution by mass, stirred, and poured into a jet cavitation device at a pressure of 160,000 kPa and a circulating cooling water bath temperature of 11°C to obtain a suspension, which was dried at 82°C to obtain a few-layer molybdenum disulfide.

[0084] S8 6g of curing agent A and 1.6g of curing agent B were mixed to obtain a curing agent; then 7g2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole was mixed with 0.5g of a few-layer molybdenum disulfide to obtain an additive;

[0085] S9.47g bisphenol A epoxy resin, 34g curing agent, 0.8g defoaming agent BYK066N, 3.5g coupling agent Z-6040, 7g benzyl glycidyl ether, 0.5g auxiliary agent, and 10g calcium carbonate were mixed and stirred evenly. Then, vacuum degassing was performed at a temperature of 35°C and a stirring rate of 260r / min to obtain a modified epoxy resin adhesive.

[0086] Example 4: A method for preparing a modified epoxy resin adhesive, comprising the following steps:

[0087] S1. Add 55g of liquid paraffin and 1.6g of 3% Span85 to a beaker, stir evenly, then add 5.2g of phenalkamine and continue stirring to obtain emulsion A;

[0088] S2. 7 g of 4,4-dicyclohexylmethane diisocyanate and 18 g of liquid paraffin were added to a beaker, stirred for 15 min, and then added dropwise to 32 g of emulsion A. The mixture was reacted at room temperature for 65 min, then heated to 53 ° C and reacted for 5.5 h. The mixture was washed with cyclohexane and air-dried to obtain curing agent A.

[0089] S3. After washing, crushing, and drying the sugarcane straw, carbonizing it at 500°C, 5g of the sugarcane straw was immersed in 25g of a 40% KOH solution, stirred for 13 hours, allowed to stand for 24 hours, and then dried at 120°C for 50 hours. After cooling, the sugarcane straw was washed twice with a 1 mol / L hydrochloric acid solution and then with deionized water, and then dried at 70°C for 4 hours to obtain biochar.

[0090] S4. To 40g of deionized water was added 0.8g of sodium dodecylbenzenesulfonate, stirred, and then 0.2g of n-octanol defoamer was added, heated to 62 ° C and stirred for 35min to obtain a mixed solution A;

[0091] S5. Mix 3.7 g of 2,4,6-tris(dimethylaminomethyl)phenol and 1 g of glyceryl tristearate and heat to 90°C for 55 min to obtain a mixture B;

[0092] S6. Add 2.5 g of mixed solution B to 140 g of mixed solution A, heat and stir at 68°C for 9 min to obtain a dispersion. Then, pour 22 g of ice water into the dispersion, filter, wash with deionized water, and dry at 60°C for 40 min. Then, add 13 g of biochar, stir for 13 min, and ultrasonicate for 5 min to obtain curing agent B.

[0093] S7. 1.5 g of molybdenum disulfide was added to 150 mL of a 95% ethanol solution by mass, stirred, and poured into a jet cavitation device at a pressure of 170,000 kPa and a circulating cooling water bath temperature of 13 ° C to obtain a suspension, which was dried at 85 ° C to obtain a few layers of molybdenum disulfide;

[0094] S8 9g of curing agent A and 1.8g of curing agent B were mixed to obtain a curing agent; then 8g2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole was mixed with 0.5g of a few-layer molybdenum disulfide to obtain an additive;

[0095] S9. Mix 50g of bisphenol A epoxy resin, 36g of curing agent, 1g of defoamer BYK066N, 4g of coupling agent Z-6040, 8g of benzyl glycidyl ether, 0.5g of auxiliary agent, and 12g of calcium carbonate. Stir thoroughly and vacuum degas at 35°C and a stirring rate of 260 r / min to obtain a modified epoxy resin adhesive.

[0096] Comparative Example 1:

[0097] Compared with Example 1, curing agent A was not added during the preparation of the modified epoxy resin adhesive in this comparative example. The remaining steps and parameters were the same and will not be repeated in this comparative example. Finally, a modified epoxy resin adhesive was obtained.

[0098] Comparative Example 2:

[0099] Compared with Example 1, curing agent B was not added during the preparation of the modified epoxy resin adhesive in this comparative example. The remaining steps and parameters were the same and will not be repeated in this comparative example. Finally, a modified epoxy resin adhesive was obtained.

[0100] Comparative Example 3:

[0101] Compared with Example 1, no auxiliary agent was added during the preparation of the modified epoxy resin adhesive in this comparative example. The remaining steps and parameters were the same and will not be repeated in this comparative example. Finally, a modified epoxy resin adhesive was obtained.

[0102] Comparative Example 4:

[0103] Compared with Example 1, biochar was not added during the preparation of curing agent B in this comparative example. The remaining steps and parameters were the same and will not be repeated in this comparative example. Finally, a modified epoxy resin adhesive was obtained.

[0104] Comparative Example 5:

[0105] Compared with Example 1, this comparative example only replaces "6g curing agent A and 1.4g curing agent B" with "6g curing agent B and 1.4g curing agent A", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a modified epoxy resin adhesive is obtained.

[0106] Comparative Example 6:

[0107] Compared with Example 1, this comparative example only replaces "4g 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and 0.3g of a few-layer molybdenum disulfide" with "4g of a few-layer molybdenum disulfide and 0.3g of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a modified epoxy resin adhesive is obtained.

[0108] Performance testing:

[0109] Storage stability test: After the modified epoxy resin adhesives prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were prepared, the viscosity of the products was tested at room temperature (24° C.), and then the products were stored under the following conditions:

[0110] Condition 1: Store at room temperature (24°C) for 3 months

[0111] Condition 2: Storage at -5°C for 18 months

[0112] After storage, return the product to 24°C and test its viscosity. If the viscosity increase does not exceed 50%, it is considered to be storable.

[0113] Referring to the ASTM D-2240 test standard, hardness tests were performed on the modified epoxy resin adhesives prepared in Examples 1 to 4 and Comparative Examples 1 to 6, respectively.

[0114] Referring to the ASTM D-638 test standard, the tensile strength test of the modified epoxy resin adhesives prepared in Examples 1 to 4 and Comparative Examples 1 to 6 was performed;

[0115] Referring to the ASTM D-638 test standard, the elongation test was performed on the modified epoxy resin adhesives prepared in Examples 1 to 4 and Comparative Examples 1 to 6, respectively;

[0116] With reference to the ISO 4587 test standard, the modified epoxy resin adhesives prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were subjected to tensile shear strength tests.

[0117] Table 1

[0118] project Storage stability hardness Tensile strength / MPa Elongation / % Tensile shear strength / MPa Example 1 qualified 85 38 15 24 Example 2 qualified 82 33 13 25 Example 3 qualified 80 35 17 27 Example 4 qualified 86 39 14 20 Comparative Example 1 Unqualified 63 23 6 14 Comparative Example 2 Unqualified 66 26 8 17 Comparative Example 3 qualified 69 25 10 16 Comparative Example 4 Unqualified 72 27 11 20 Comparative Example 5 qualified 68 25 9 16 Comparative Example 6 qualified 70 27 11 21

[0119] Data Analysis:

[0120] As can be seen from Table 1, the modified epoxy resin adhesive prepared by the present invention has better storage stability, higher hardness, tensile strength, elongation and tensile shear strength. This may be because the curing agent in the present invention is obtained by mixing curing agent A and curing agent B, wherein the curing agent A prepared with phenolic amine as the core material and isocyanate as the wall material can break and release the curing agent at a higher temperature, and then cure with the epoxy resin; and in the curing agent B that can be cured at medium and low temperatures, the core material 2,4,6-tris(dimethylaminomethyl)phenol is wrapped in tristearate and combined with biochar due to adsorption, which can further enhance the stability of curing agent B in the adhesive, and biochar can also be used as a filler to enhance the interfacial adhesion of the epoxy resin; the 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole in the auxiliary agent can effectively absorb ultraviolet rays and convert them into heat energy, promoting curing. The rupture and release of the activator, and by absorbing ultraviolet radiation, reduce ultraviolet damage to the material, thereby reducing the generation of cracks inside the material; the few layers of molybdenum disulfide in the additive can also absorb photon energy and convert it into heat energy, and can further improve the mechanical properties of the epoxy resin adhesive. The two work synergistically and work together with the curing agent. During the curing temperature rise process, the tristearate in the curing agent B, which can be cured at medium and low temperatures, first breaks and releases 2,4,6-tris(dimethylaminomethyl)phenol, which is cured first. When heated to a certain temperature, the curing agent A breaks and cures with the epoxy resin, which improves the curing rate while avoiding large thermal stress and uneven mixing inside the epoxy resin caused by rapid heating, thereby affecting the curing effect; and the curing agent A and the curing agent B are mixed in a specific ratio, which not only improves the overall curing rate but also avoids overly tight cross-linking, which makes the system brittle, thereby affecting the impact resistance of the epoxy resin adhesive.

[0121] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0122] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A modified epoxy resin adhesive, characterized in that: Including the following raw materials by weight: Bisphenol A epoxy resin 41-50 parts; curing agent 28-36 parts; defoaming agent 0.5-1 parts; coupling agent 2-4 parts; diluent 4-8 parts; auxiliary agent 0.3-0.5 parts; filler 7-12 parts; The curing agent is obtained by mixing curing agent A and curing agent B in a mass ratio of 6-9:1.4-1.8; The curing agent A is prepared from phenolic amine and 4,4,-dicyclohexylmethane diisocyanate; The curing agent B is prepared from 2,4,6-tris(dimethylaminomethyl)phenol, tristearate and biochar; The auxiliary agent is obtained by mixing auxiliary agent A and auxiliary agent B in a mass ratio of 4-8:0.3-0.5; The auxiliary agent A is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole; The auxiliary agent B is a few-layer molybdenum disulfide.

2. The modified epoxy resin adhesive according to claim 1, characterized in that The preparation method of the curing agent A is as follows: Step A1. Add liquid paraffin and 3% by mass of Span85 to a beaker, stir evenly, then add phenalkamine and continue stirring to obtain Emulsion A. Step A2. Add 4,4-dicyclohexylmethane diisocyanate and liquid paraffin to a beaker, stir for 10-15 minutes, and then add dropwise to emulsion A. React at room temperature for 50-65 minutes. After heating for reaction, wash with cyclohexane and air-dry naturally to obtain curing agent A.

3. The modified epoxy resin adhesive according to claim 2, characterized in that The mass ratio of liquid paraffin, Span85 and phenalkamine in step A1 is 47-55:1.3-1.6:4.5-5.2; The mass ratio of 4,4,-dicyclohexylmethane diisocyanate, liquid paraffin and emulsion A in step A2 is 4-7:10-18:25-32; The temperature during the heating reaction is 45-53° C. and the time is 4.5-5.5 hours.

4. The modified epoxy resin adhesive according to claim 1, characterized in that The preparation method of the curing agent B is as follows: Step B1. After cleaning, crushing, and drying the sugarcane straw, carbonizing it at 450-500°C, 5g of the sugarcane straw was soaked in 20-25g of a 40% KOH solution, stirred for 12-13 hours, allowed to stand for 20-24 hours, and then dried at 110-120°C for 48-50 hours. After cooling, the sugarcane straw was washed twice with a 1 mol / L hydrochloric acid solution and then with deionized water, and then dried at 60-70°C for 3-4 hours to obtain biochar. Step B2. Add a surfactant to deionized water, stir evenly, then add n-octanol defoamer, heat and stir to obtain a mixed solution A; Step B3. Mixing 2,4,6-tris(dimethylaminomethyl)phenol and glyceryl tristearate and heating to obtain a mixture B; Step B4. Add mixed solution B to mixed solution A, heat and stir to obtain a dispersion, then pour ice water into the dispersion, filter, wash with deionized water, and dry, then add to biochar, stir for 8-13 minutes, and ultrasonically treat for 2-5 minutes to obtain curing agent B.

5. The modified epoxy resin adhesive according to claim 4, characterized in that The mass ratio of deionized water, surfactant and defoaming agent in step B2 is 30-40:0.72-0.8:0.1-0.2; The surfactant is any one of sodium dodecylbenzenesulfonate and Tween; The temperature during the heating and stirring is 55-62°C and the time is 25-35 minutes; The mass ratio of 2,4,6-tris(dimethylaminomethyl)phenol to tristearin in step B3 is 2.3-3.7:1; The heating temperature is 82-90° C. and the heating time is 40-55 minutes.

6. The modified epoxy resin adhesive according to claim 4, characterized in that The mass ratio of mixed solution B, mixed solution A, ice water and biochar is 1.6-2.5:130-140:18-22:8-13; The temperature during the heating and stirring is 60-68°C and the time is 6-9 minutes; The drying temperature is 55-60° C. and the drying time is 30-40 minutes.

7. The modified epoxy resin adhesive according to claim 1, characterized in that The preparation method of the auxiliary agent B is as follows: Molybdenum disulfide was added to a 95% ethanol solution by mass, stirred evenly, and then poured into a jet cavitation device. The parameters were set to obtain a suspension, and the suspension was dried at 75-85°C to obtain a few-layer molybdenum disulfide. The molybdenum disulfide and ethanol solution are used in a ratio of 1-1.5 g to 100-150 mL. The pressure in the parameters is 150000-170000 KPa, and the temperature of the circulating cooling water bath is 8-13°C.

8. The modified epoxy resin adhesive according to claim 1, characterized in that The diluent is at least one of benzyl glycidyl ether, neodecanoic acid glycidyl ester, and phenyl glycidyl ether; The filler is any one of calcium carbonate and silicon powder; The defoamer is defoamer BYK066N; The coupling agent is coupling agent Z-6040.

9. The method for preparing the modified epoxy resin adhesive according to any one of claims 1 to 8, characterized in that: The following steps are involved: Mix bisphenol A epoxy resin, curing agent, defoaming agent, coupling agent, diluent, additives and filler, stir evenly, and perform vacuum degassing to obtain modified epoxy resin adhesive; The stirring rate during the degassing is 200-260 r / min and the temperature is 30-35°C.

10. The use of the modified epoxy resin adhesive according to any one of claims 1 to 8, characterized in that: The modified epoxy resin adhesive is used as an adhesive in the field of construction.