A modified epoxy resin and its preparation method and use

Abstract

This invention belongs to the field of resin materials technology, and relates to a modified epoxy resin, its preparation method, and its uses. The modified epoxy resin comprises component A and component B. The raw materials for preparing component A contain 60-100 parts by weight of epoxy resin; the raw materials for preparing component B contain 10-45 parts by weight of an amine curing agent and 5-40 parts by weight of aspartic polyurea prepolymer. Using the modified epoxy resin and its preparation method of this invention, the chemical reaction between the epoxy groups in the epoxy resin and the secondary amine groups in the aspartic polyurea prepolymer can easily and readily introduce polyaspartic ester segments into the epoxy resin molecule. This significantly improves the toughness, elongation at break, impact resistance, and fatigue resistance of the epoxy resin while maintaining its high strength, making it suitable for preparing high-performance epoxy resin coatings, adhesives, flooring, and repair mortars, etc., and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of resin materials and relates to a modified epoxy resin and a preparation method and application thereof. Background Art

[0002] Epoxy resin is a class of compounds containing two or more epoxy groups in the molecule. It is the polycondensation product of epichlorohydrin and bisphenol A, polyols, polyacids or polyamines. The curing reaction of epoxy resin and curing agent can form a three-dimensional cross-linked network structure, which gives it excellent thermal properties, high dimensional stability, good mechanical properties, adhesion and processability and other excellent properties.

[0003] Epoxy resins are widely used in aerospace, electronics, transportation, construction and chemical industries. However, the shortcomings of epoxy resins, such as high brittleness and poor toughness, also restrict their application. Toughening modification can broaden the application of epoxy resins in the field of high impact fracture strength and high toughness materials. Therefore, toughening modification of epoxy resins has always been a hot topic in scientific research.

[0004] Common epoxy resin modification methods include physical modification and chemical modification. Physical modification is to blend rubber elastomer or thermoplastic resin with good heat resistance as the second component with epoxy resin; chemical modification is to change the chemical structure of the cross-linked network, such as introducing "flexible segments" into the cross-linked network to improve the activity of the network chain molecules, or increase the distance between cross-linking points.

[0005] Polyurethane modified epoxy resin is a chemical modification method that can not only introduce flexible segments into the epoxy resin network structure, but also polyurethane contains active amide groups and has good compatibility with epoxy resin, which are all favorable factors for polyurethane modified epoxy resin. However, the introduction of polyurethane flexible segments also significantly reduces the strength and heat resistance of epoxy resin. Therefore, for high-strength and high-toughness epoxy resin systems, polyurethane modified epoxy resin is difficult to meet the performance requirements.

[0006] Polyaspartic acid ester (structural formula shown in Formula I below) is a macromolecular compound with secondary amine groups, which has large steric hindrance, and the high-density ester bonds on the side chains also provide strong polar groups for the macromolecular chains. Polyaspartic acid ester has a small molecular weight and low viscosity, and its cured product polyaspartic acid ester polyurea (abbreviated as aspartic acid polyurea) has strong cohesion, high strength, good toughness, high hardness, good adhesion to the base surface, good weather resistance, and good acid and alkali resistance. Therefore, compared with polyurethane, aspartic acid polyurea has more outstanding mechanical properties. The reaction principle of polyaspartic acid ester polyurea (aspartic acid polyurea) is shown in Formula II below.

[0007] Summary of the invention

[0008] The primary purpose of the present invention is to provide a modified epoxy resin, which can introduce multiple repeating polyaspartic acid ester segments into the epoxy resin network structure through chemical modification, and significantly improve the toughness, elongation at break, impact resistance and fatigue resistance of the epoxy resin while maintaining the high strength of the epoxy resin, so that it is suitable for preparing high-performance epoxy resin coatings, adhesives, flooring and repair mortars, etc., and has broad application prospects.

[0009] To achieve this object, in a basic embodiment, the present invention provides a modified epoxy resin, wherein the modified epoxy resin comprises component A and component B.

[0010] The raw materials for preparing the A component include 60-100 parts of epoxy resin by weight;

[0011] The raw materials for preparing the B component include 10-45 parts of amine curing agent and 5-40 parts of aspartame prepolymer by weight.

[0012] In a preferred embodiment, the present invention provides a modified epoxy resin, wherein the epoxy resin is a compound containing two or more epoxy groups in the molecule, selected from one or more of bisphenol A epoxy resins E-44, E-51, and E-20.

[0013] In a preferred embodiment, the present invention provides a modified epoxy resin, wherein the amine curing agent is an organic amine compound selected from one or more of aliphatic amines, alicyclic amines, aromatic amines and polyamides.

[0014] In a preferred embodiment, the present invention provides a modified epoxy resin, wherein the raw materials for preparing the aspartic polyurea prepolymer include 2-10 parts of diisocyanate and 90-98 parts of polyaspartic acid ester in a weight ratio;

[0015] The molar ratio R of polyaspartic acid ester to diisocyanate in the aspart polyurea prepolymer is 2.1-3, the polyaspartic acid ester is excessive, all -NCO groups react, and the obtained aspart polyurea prepolymer has no -NCO group, does not react with moisture, and has good storage stability.

[0016] In a more preferred embodiment, the present invention provides a modified epoxy resin, wherein:

[0017] The diisocyanate is selected from one or more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), and lysine diisocyanate (LDI);

[0018] The polyaspartic acid ester is a reaction product of a secondary amine group and an isocyanate, and is one or more of F-420, F-520, NH-1420, and NH-1520.

[0019] In a more preferred embodiment, the present invention provides a modified epoxy resin, wherein the preparation method of the aspartame prepolymer comprises the following steps:

[0020] (1) adding polyaspartic acid ester into a reaction kettle, stirring and heating to 100-130° C., and dehydrating under vacuum conditions for 1-4 hours;

[0021] (2) lowering the temperature to below 50°C, starting stirring (speed of 300-1000 r / mim), slowly adding diisocyanate, reacting for 0.5-2 hours, then raising the temperature to 60-90°C, and continuing the reaction for 2-3 hours;

[0022] (3) After the reaction is completed, the temperature is lowered to below 50°C and the material is discharged for later use.

[0023] In a preferred embodiment, the present invention provides a modified epoxy resin, wherein the raw materials for preparing the A component further comprise 1-10 parts of a reactive diluent, 0-300 parts of a pigment, 0-40 parts of a solvent, and 0-5 parts of a high-performance additive by weight ratio;

[0024] The raw materials for preparing the B component further include 0-2 parts of an accelerator, 0-220 parts of a pigment and filler, 0-30 parts of a solvent, and 0-5 parts of a high-performance additive in terms of weight ratio.

[0025] In a preferred embodiment, the present invention provides a modified epoxy resin, wherein:

[0026] The reactive diluent is a low molecular weight epoxy compound containing an epoxy group, selected from one or more of propylene oxide propylene ether, butyl glycidyl ether, glycerol epoxy resin, and epichlorohydrin, preferably one or more of propylene oxide butyl ether (501), dipropylene oxide ethyl ether (669), tripropylene oxide propyl ether (662), and propylene oxide benzyl ether (692);

[0027] The pigment filler is selected from one or more of titanium dioxide, iron yellow, iron red, carbon black, kaolin, cement, heavy calcium, barium sulfate, magnesium oxide, calcium oxide, wollastonite, silica powder, and talc;

[0028] The solvent is an inactive diluent selected from one or more of n-butanol, toluene, xylene, solvent oil, cyclohexanone, and butyl acetate;

[0029] The high-performance additive is one or more of a defoamer, a leveling agent, an anti-settling agent, a thixotropic agent, and a coupling agent;

[0030] The accelerator is an amine accelerator, selected from one or more of DMP-30, triethylamine, triethanolamine and pyridine.

[0031] The second object of the present invention is to provide a method for preparing the modified epoxy resin as described above, so as to utilize the chemical reaction between the epoxy group in the epoxy resin and the secondary amine group in the aspartic acid polyurea prepolymer to simply and easily introduce the polyaspartic acid ester segment into the epoxy resin molecule, thereby significantly improving the toughness, elongation at break, impact resistance and fatigue resistance of the epoxy resin while maintaining the high strength of the epoxy resin, so that the epoxy resin is suitable for preparing high-performance epoxy resin coatings, adhesives, floorings and repair mortars, etc., and has broad application prospects.

[0032] To achieve this object, in a basic embodiment, the present invention provides a method for preparing the modified epoxy resin as described above, the preparation method comprising the following steps:

[0033] (1) Preparation of component A: Add the raw materials in proportion to a stirred tank and mix for 1-3 hours. Then, according to the particle size requirements, stir or grind to the corresponding particle size to obtain component A;

[0034] (2) Preparation of component B: Add the raw materials in proportion to a stirred tank and mix for 1-3 hours. Then, according to the particle size requirements, stir or grind to the corresponding particle size to obtain component B;

[0035] (3) Mix component A and component B in a certain proportion and solidify them during construction at room temperature.

[0036] The third object of the present invention is to provide the use of the modified epoxy resin as described above for preparing high-performance epoxy resin coatings, adhesives, flooring or repair mortar.

[0037] To achieve this object, in a basic embodiment, the present invention provides the use of the modified epoxy resin as described above for preparing high-performance epoxy resin coatings, adhesives, floors or repair mortars.

[0038] The beneficial effect of the present invention is that by utilizing the modified epoxy resin and the preparation method thereof, the chemical reaction between the epoxy group in the epoxy resin and the secondary amine group in the aspartic acid polyurea prepolymer can be utilized to simply and easily introduce the polyaspartic acid ester segment into the epoxy resin molecule, thereby significantly improving the toughness, elongation at break, impact resistance and fatigue resistance of the epoxy resin while maintaining the high strength of the epoxy resin, making the epoxy resin suitable for preparing high-performance epoxy resin coatings, adhesives, floor coverings and repair mortars, etc., and having broad application prospects. DETAILED DESCRIPTION

[0039] The specific embodiments of the present invention are further described below in conjunction with the examples. The reagents and equipment in the examples can all be purchased from the market.

[0040] Example 1: Preparation of modified epoxy resin (I)

[0041] This embodiment provides an asparagine polyurea modified epoxy resin. The raw material formula for preparing component A includes: 100 kg of epoxy resin (E-51); the raw material formula for preparing component B includes: 40 kg of amine curing agent (650) and 10 kg of asparagine polyurea prepolymer.

[0042] The specific preparation steps are as follows:

[0043] Preparation of component A:

[0044] Add 100 kg of epoxy resin (E-51) into the stirring kettle and pack for later use to obtain component A and component B:

[0045] 40 kg of amine curing agent (650) and 10 kg of aspartame prepolymer were added into a stirring kettle and mixed for 1 hour. After mixing evenly, component B was obtained and packaged for later use.

[0046] Wherein, the preparation of asparagine polyurea prepolymer:

[0047] 1) Add 94.8 kg of polyaspartic acid ester (F-420) into a reactor, stir and heat to 100° C., and dehydrate under vacuum for 4 hours;

[0048] 2) Lower the temperature to below 50°C, start high-speed stirring (stirring speed 500r / min), slowly add 5kg of toluene diisocyanate (TDI), react for 1 hour, then raise the temperature to 70°C and continue to react for 2 hours;

[0049] 3) After the reaction is completed, cool to below 50°C and discharge the material for later use.

[0050] During construction, mix components A and B evenly in a mass ratio of 2:1 and cure at room temperature.

[0051] Example 2: Preparation of modified epoxy resin (II)

[0052] The present embodiment provides an asparagine polyurea modified epoxy resin. The raw material formula for preparing component A includes: 95 kg of epoxy resin (E-51) and 5 kg of reactive diluent (692); the raw material formula for preparing component B includes: 20 kg of amine curing agent (T31), 15 kg of amine curing agent (650), 15 kg of asparagine polyurea prepolymer, and 1 kg of accelerator (DMP-30).

[0053] The specific preparation steps are as follows:

[0054] Preparation of component A:

[0055] 95 kg of epoxy resin (E-51) and 5 kg of active diluent (692) were added into a stirring kettle in sequence and stirred for 1 hour. Component A was obtained by mixing evenly and packaged for later use.

[0056] Preparation of component B:

[0057] 20 kg of amine curing agent (T31), 15 kg of amine curing agent (650), 15 kg of asparagine polyurea prepolymer, and 1 kg of accelerator (DMP-30) were added to a stirring kettle and mixed for 1 hour. After mixing evenly, component A was obtained and packaged for later use.

[0058] Wherein, the preparation of asparagine polyurea prepolymer:

[0059] 1) Add 98 kg of polyaspartic acid ester (F-5 20) into a reactor, stir and heat to 110°C, and dehydrate under vacuum for 3 hours;

[0060] 2) Lower the temperature to below 50°C, start high-speed stirring (stirring speed 800r / min), slowly add 2kg of toluene diisocyanate (TDI), react for 1 hour, then raise the temperature to 90°C and continue to react for 3 hours;

[0061] 3) After the reaction is completed, cool to below 50°C and discharge the material for later use.

[0062] During construction, mix components A and B evenly in a mass ratio of 2:1 and cure at room temperature.

[0063] Example 3: Preparation of modified epoxy resin (III)

[0064] The present embodiment provides an asparagine polyurea modified epoxy resin building structural adhesive. The raw material formula for preparing component A includes: 45 kg of epoxy resin (E-51), 45 kg of epoxy resin (E-44), 10 kg of reactive diluent (501), 150 kg of pigment (600 mesh heavy calcium), 1 kg of defoamer (BYK-065), and 1 kg of thixotropic agent (fumed silica); the raw material formula for preparing component B includes: 10 kg of amine curing agent (T31), 25 kg of asparagine polyurea prepolymer, 0.5 kg of accelerator (DMP-30), 50 kg of pigment (600 mesh heavy calcium), and 0.5 kg of coupling agent (KH-550).

[0065] The specific preparation steps are as follows:

[0066] Preparation of component A:

[0067] 45 kg of epoxy resin (E-51), 45 kg of epoxy resin (E-44), 10 kg of active diluent (501), 1 kg of defoamer (BYK-065), 1 kg of thixotropic agent (fumed silica), and 150 kg of pigment (600 mesh heavy calcium) were sequentially added into a stirring tank and mixed for 2 hours. Then, according to the particle size requirements, the mixture was stirred to the corresponding particle size to obtain component A, which was packaged for later use.

[0068] Preparation of component B:

[0069] 10kg of amine curing agent (T31), 25kg of asparagine polyurea prepolymer, 0.5kg of accelerator (DMP-30), 50kg of pigment (600 mesh heavy calcium), and 0.5kg of coupling agent (KH-550) are added to the stirring kettle in sequence and mixed for 2h. Then, according to the particle size requirements, the B component is prepared after stirring to the corresponding particle size and packaged for later use.

[0070] Wherein, the preparation of asparagine polyurea prepolymer:

[0071] 1) Add 90 kg of polyaspartic acid into a reactor, stir and heat to 130° C., and dehydrate under vacuum for 1 hour;

[0072] 2) The temperature was lowered to below 50°C, high-speed stirring was started (stirring speed 1000 r / min), 10 kg of diisocyanate (MDI-50) was slowly added, and the reaction was continued for 1 hour, then the temperature was raised to 60°C and the reaction was continued for 3 hours;

[0073] 3) After the reaction is completed, cool to below 50°C and discharge the material for later use.

[0074] During construction, mix components A and B evenly in a mass ratio of 3:1 and cure at room temperature.

[0075] Example 4: Preparation of modified epoxy resin (IV)

[0076] The present embodiment provides an asparagine polyurea modified epoxy resin repair mortar. The raw material formula for preparing component A includes: 70 kg of epoxy resin (E-44), 30 kg of active diluent (692), 250 kg of pigment (200 mesh quartz sand), and 2 kg of pigment (titanium dioxide); the raw material formula for preparing component B includes: 15 kg of amine curing agent (T31), 20 kg of amine curing agent (593), 15 kg of asparagine polyurea prepolymer, 1 kg of accelerator (DMP-30), 125 kg of pigment (200 mesh quartz sand), 1 kg of pigment (iron black), and 1 kg of coupling agent (KH-550).

[0077] The specific preparation steps are as follows:

[0078] Preparation of component A:

[0079] 70 kg of epoxy resin (E-44), 30 kg of active diluent (692), 250 kg of pigment (200 mesh quartz sand), and 2 kg of pigment (titanium dioxide) are sequentially added into a stirring kettle and mixed for 2 hours. Then, according to the particle size requirements, component A is obtained after grinding to the corresponding particle size and packaging.

[0080] Preparation of component B:

[0081] 15 kg of amine curing agent (T31), 20 kg of amine curing agent (593), 15 kg of asparagine polyurea prepolymer, 1 kg of accelerator (DMP-30), 125 kg of pigment (200 mesh quartz sand), 1 kg of pigment (iron black), and 1 kg of coupling agent (KH-550) are added to a stirring kettle in sequence and mixed for 2 hours. Then, according to the particle size requirements, the component B is obtained after grinding to the corresponding particle size and packaging for later use.

[0082] Wherein, the preparation of asparagine polyurea prepolymer:

[0083] 1) Add 92 kg of polyaspartic acid into a reactor, stir and heat to 130° C., and dehydrate under vacuum for 1 hour;

[0084] 2) The temperature was lowered to below 50°C, high-speed stirring was started (stirring speed 1000 r / min), 8 kg of hexamethylene diisocyanate (HDI) was slowly added, and the reaction was continued for 1 hour, and then the temperature was raised to 90°C and the reaction was continued for 2 hours;

[0085] 3) After the reaction is completed, cool to below 50°C and discharge the material for later use.

[0086] During construction, mix components A and B evenly in a mass ratio of 2:1 and cure at room temperature.

[0087] Example 5: Preparation of modified epoxy resin (V)

[0088] The present embodiment provides an asparagus polyurea modified epoxy resin floor coating. The raw material formula for preparing component A includes: 60 kg of epoxy resin (E-20), 20 kg of epoxy resin (E-44), 1 kg of active diluent (501), 2.5 kg of defoamer (BYK-065), 2.5 kg of leveling agent (BYK-333), 20 kg of solvent (n-butanol and xylene in a mass ratio of 1:1), 300 kg of pigment (325 mesh quartz powder), 100 kg of granulated powder, ... kg, pigment and filler (iron yellow) 2kg; the raw material formula for preparing component B includes: amine curing agent (9201) 20kg, aspartame polyurea prepolymer 30kg, accelerator (DMP-30) 2kg, defoamer (BYK-065) 2kg, leveling agent (BYK-333) 2kg, solvent (n-butanol and xylene mass ratio 1:1) 10kg, pigment and filler (iron black) 1kg, pigment and filler (325 mesh quartz powder) 150kg.

[0089] The specific preparation steps are as follows:

[0090] Preparation of component A:

[0091] 60 kg of epoxy resin (E-20), 20 kg of epoxy resin (E-44), 1 kg of active diluent (501), 2.5 kg of defoamer (BYK-065), 2.5 kg of leveling agent (BYK-333), 20 kg of solvent (n-butanol and xylene mass ratio 1:1), 300 kg of pigment (325 mesh quartz powder), 2 kg of pigment (iron yellow) are added into a stirring tank in sequence and mixed for 3 hours. Then, according to the particle size requirements, the components are ground to the corresponding particle size to obtain component A, which is packaged for later use.

[0092] Preparation of component B:

[0093] 20 kg of amine curing agent (9201), 30 kg of asparagine polyurea prepolymer, 2 kg of accelerator (DMP-30), 2 kg of defoamer (BYK-065), 2 kg of leveling agent (BYK-333), 10 kg of solvent (n-butanol and xylene mass ratio of 1:1), 1 kg of pigment (iron black), 150 kg of pigment (325 mesh quartz powder) are added into a stirring kettle in sequence and mixed for 3 hours. Then, according to the particle size requirements, grind to the corresponding particle size to obtain component B, which is packaged for later use.

[0094] Wherein, the preparation of asparagine polyurea prepolymer:

[0095] 1) Add 92 kg of polyaspartic acid into a reactor, stir and heat to 130° C., and dehydrate under vacuum for 1 hour;

[0096] 2) The temperature was lowered to below 50°C, high-speed stirring was started (stirring speed 300 r / min), 8 kg of isophorone diisocyanate (IPDI) was slowly added, and the reaction was continued for 1 hour, and then the temperature was raised to 90°C and the reaction was continued for 2 hours;

[0097] 3) After the reaction is completed, cool to below 50°C and discharge the material for later use.

[0098] During construction, mix components A and B evenly in a mass ratio of 2:1 and cure at room temperature.

[0099] Example 6: Preparation of modified epoxy resin (VI)

[0100] The present embodiment provides a two-component modified epoxy resin anti-corrosion coating. The raw material formula for preparing component A includes: 60 kg of epoxy resin (E-20), 10 kg of active diluent (743), 1 kg of defoamer (BYK-065), 1 kg of leveling agent (BYK-333), 40 kg of solvent (xylene), 100 kg of pigments and fillers (mica powder), and 100 kg of pigments and fillers (precipitated barium sulfate); the raw material formula for preparing component B includes: 30 kg of amine curing agent (MH-3165), 10 kg of amine curing agent (650), 40 kg of asparagine polyurea prepolymer, 1 kg of accelerator (DMP-30), 30 kg of solvent (xylene), 1 kg of defoamer (BYK-065), 1 kg of leveling agent (BYK-333), 110 kg of pigments and fillers (mica powder), and 110 kg of pigments and fillers (precipitated barium sulfate).

[0101] The specific preparation steps are as follows:

[0102] Preparation of component A:

[0103] 60 kg of epoxy resin (E-20), 10 kg of active diluent (743), 1 kg of defoamer (BYK-065), 1 kg of leveling agent (BYK-333), 40 kg of solvent (xylene), 100 kg of pigment (mica powder), and 100 kg of pigment (precipitated barium sulfate) are sequentially added into a stirring tank and mixed for 2 hours. Then, according to the particle size requirements, component A is obtained after grinding to the corresponding particle size and packaging for later use.

[0104] Preparation of component B:

[0105] 30 kg of amine curing agent (MH-3165), 10 kg of amine curing agent (650), 40 kg of asparagine polyurea prepolymer, 1 kg of accelerator (DMP-30), 30 kg of solvent (xylene), 1 kg of defoaming agent (BYK-065), 1 kg of leveling agent (BYK-333), 110 kg of pigments and fillers (mica powder), and 110 kg of pigments and fillers (precipitated barium sulfate) are sequentially added into a stirring kettle and mixed for 2 hours. Then, according to the particle size requirements, the components are ground to the corresponding particle size to obtain component B, which is packaged for later use.

[0106] Wherein, the preparation of asparagine polyurea prepolymer:

[0107] 1) Add 94.8 kg of polyaspartic acid ester (HN-420) into a reactor, stir and heat to 100° C., and dehydrate under vacuum for 4 hours;

[0108] 2) The temperature was lowered to below 50°C, high-speed stirring was started (stirring speed 800 r / min), 5 kg of toluene diisocyanate (TDI) was slowly added, and the reaction was continued for 1 hour, and then the temperature was raised to 70°C and the reaction was continued for 2.5 hours;

[0109] 3) After the reaction is completed, cool to below 50°C and discharge the material for later use.

[0110] During construction, mix components A and B in a mass ratio of 1:1 and cure at room temperature.

[0111] Example 7: Performance test of the modified epoxy resin obtained in Examples 1-6

[0112] The properties of the modified epoxy resins obtained in Examples 1-6 were tested according to relevant industry standards and national standards. The results are shown in Table 1 below.

[0113] Table 1 Performance test results of modified epoxy resin obtained in Examples 1-6

[0114]

[0115]

[0116] The asparagine polyurea modified epoxy resin material in Examples 1-6 introduces multiple polyaspartic acid ester segments into the epoxy resin molecule by utilizing the reaction between the epoxy group in the epoxy resin and the secondary amine group of the asparagine polyurea prepolymer, thereby improving the toughness, elongation at break, impact resistance and fatigue resistance of the adhesive while maintaining the high strength of the epoxy resin structural adhesive. The above preparation method is simple and highly operable, and is suitable for preparing high-performance building structural adhesives, anti-corrosion coatings, floor adhesives, repair mortars and other materials.

[0117] The above embodiments are merely illustrative of the present invention, and the present invention may also be implemented in other specific ways or other specific forms without departing from the gist or essential features of the present invention. Therefore, the described embodiments should be considered illustrative rather than restrictive in any respect. The scope of the present invention should be described by the appended claims, and any changes equivalent to the intent and scope of the claims should also be included within the scope of the present invention.

Claims

1. A modified epoxy resin, characterized in that: The modified epoxy resin comprises component A and component B. The raw materials for preparing the A component include 60-100 parts of epoxy resin by weight; The raw materials for preparing the B component include 10-45 parts of amine curing agent and 5-40 parts of aspartame prepolymer by weight; The raw materials for preparing the aspartame polyurea prepolymer include 2-10 parts of diisocyanate and 90-98 parts of polyaspartic acid ester in weight ratio; The molar ratio R of polyaspartic acid ester to diisocyanate in the aspartic acid polyurea prepolymer is 2.1-3, the polyaspartic acid ester is excessive, all -NCO groups react, and the obtained aspartic acid polyurea prepolymer has no -NCO group, does not react with moisture, and has good storage stability; The preparation method of the asparagine polyurea prepolymer comprises the following steps: (1) adding polyaspartic acid ester into a reaction kettle, stirring and heating to 100-130° C., and dehydrating under vacuum conditions for 1-4 hours; (2) lowering the temperature to below 50°C, starting stirring, slowly adding diisocyanate, reacting for 0.5-2 hours, then raising the temperature to 60-90°C, and continuing the reaction for 2-3 hours; (3) After the reaction is completed, the temperature is lowered to below 50°C and the material is discharged for standby use; The amine curing agent is 650, or T31, or a mixture of T31 and 650, or a mixture of T31 and 593.

2. The modified epoxy resin according to claim 1, characterized in that: The epoxy resin is a compound containing two or more epoxy groups in a molecule, and is selected from one or more of bisphenol A epoxy resins E-44, E-51, and E-20.

3. The modified epoxy resin according to claim 1, characterized in that: The diisocyanate is selected from one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate; The polyaspartic acid ester is a reaction product of a secondary amine group and an isocyanate, and is one or more of F-420, F-520, NH-1420, and NH-1520.

4. The modified epoxy resin according to any one of claims 1 to 3, characterized in that: The raw materials for preparing the A component further include 1-10 parts of active diluent, 0-300 parts of pigment filler, 0-40 parts of solvent, and 0-5 parts of high-performance additives according to weight ratio; The raw materials for preparing the B component further include 0-2 parts of an accelerator, 0-220 parts of a pigment and filler, 0-30 parts of a solvent, and 0-5 parts of a high-performance additive in terms of weight ratio.

5. The modified epoxy resin according to claim 4, characterized in that: The active diluent is a low molecular weight epoxy compound containing an epoxy group, selected from one or more of propylene oxide propylene ether, butyl glycidyl ether, glycerol epoxy resin, and epichlorohydrin; The pigment filler is selected from one or more of titanium dioxide, iron yellow, iron red, carbon black, kaolin, cement, heavy calcium, barium sulfate, magnesium oxide, calcium oxide, wollastonite, silica powder, and talc; The solvent is an inactive diluent selected from one or more of n-butanol, toluene, xylene, solvent oil, cyclohexanone, and butyl acetate; The high-performance additive is one or more of a defoamer, a leveling agent, an anti-settling agent, a thixotropic agent, and a coupling agent; The accelerator is an amine accelerator, selected from one or more of DMP-30, triethylamine, triethanolamine and pyridine.

6. A method for preparing a modified epoxy resin according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: (1) Preparation of component A: Add the raw materials in proportion to a stirred tank and mix for 1-3 hours. Then, according to the particle size requirements, stir or grind to the corresponding particle size to obtain component A; (2) Preparation of component B: Add the raw materials in proportion to a stirred tank and mix for 1-3 hours. Then, according to the particle size requirements, stir or grind to the corresponding particle size to obtain component B; (3) Mix component A and component B in a certain proportion and solidify them during construction at room temperature.

7. Use of the modified epoxy resin according to any one of claims 1 to 5 for preparing high-performance epoxy resin coatings, adhesives, floor coverings or repair mortars.

Images