A fast-curing epoxy floor coating and a method for preparing the same

Abstract

This invention relates to a rapid-curing epoxy floor coating and its preparation method, belonging to the field of coating technology. Through the synergistic effect of hydrophobic modification of siloxanes and shielding by three-dimensional network blended fillers, a comprehensive anti-corrosion and water-resistant system from the surface to the interior is constructed. This solves the common industry problems of high water absorption, easy water vapor penetration, easy whitening and blistering under long-term high humidity, and interlayer delamination in traditional water-based epoxy floor coatings. In the preparation process of the modified epoxy resin, long-chain hydrophobic flexible segments of polypropylene glycol are introduced, and hydrophobic segments are also introduced through esterification grafting to achieve physical hydrophobicity. Then, hyperbranched macromolecules are synthesized in situ, and flexible acidified polyamide is covalently bonded to rigid lanthanum trioxide, constructing a continuous three-dimensional cross-linked network inside the coating. This fills the micropores of the epoxy matrix, extends the penetration path of corrosive media, and improves the anti-corrosion performance of the epoxy floor coating in harsh corrosive environments.

Description

Technical Field

[0001] This invention belongs to the field of coating technology and relates to a rapid-curing epoxy floor coating and its preparation method. Background Technology

[0002] With its excellent adhesion, wear and corrosion resistance, easy cleaning, and good decorative properties, epoxy floor coatings have become the mainstream floor coating material for industrial plants, underground garages, warehousing and logistics, electronic cleanrooms, precision manufacturing workshops, and other places, playing a key role in improving the durability, cleanliness, and efficiency of the floor.

[0003] Currently, most mainstream two-component epoxy flooring systems use conventional aliphatic amines and polyamides as curing agents, which have significant drawbacks under normal temperature construction conditions: long curing cycles, with surface drying typically requiring 4-8 hours, actual drying ≥24 hours, and complete cross-linking curing taking up to 7 days. To address the slow curing issue, existing technologies often introduce low-molecular-weight, highly reactive amines and add phenolic or tertiary amine accelerators to achieve rapid curing. However, these methods generally suffer from insufficient balance between performance and application: rapid curing can lead to concentrated exothermic reactions, increased internal stress in the paint film, resulting in shrinkage cracking and poor leveling properties; increased brittleness of the paint film, decreased impact and scratch resistance, and simultaneous decline in resistance to chemical media and yellowing; some systems have excessively short pot life, poor on-site operability, and are difficult to adapt to large-area continuous construction. Furthermore, most rapid-curing formulations struggle to achieve key properties such as abrasion resistance, impermeability, and heavy-load tolerance, failing to meet the long-term application requirements of demanding conditions such as heavy traffic, high cleanliness, and high corrosion.

[0004] Chinese invention patent application CN112812651A discloses a graphene-based wear-resistant epoxy floor coating that can cure quickly. It includes a water-based epoxy sealing primer, a water-based epoxy floor intermediate coat, and a water-based epoxy floor topcoat. The water-based epoxy sealing primer, water-based epoxy floor intermediate coat, and water-based epoxy floor topcoat are all composed of component A and component B. Both component A and component B contain polyamide resin curing agent and graphene, which have the characteristics of fast curing speed and good physical properties.

[0005] The coatings in the above scheme are prone to microscopic defects such as micropores and microcracks after curing and molding, which cannot effectively block the penetration of alkaline media. They still have technical defects such as poor alkali resistance, easy blistering and whitening in alkaline environment, and interlayer peeling. Summary of the Invention

[0006] The purpose of this invention is to provide a fast-curing epoxy floor coating and its preparation method. By preparing a highly active fast-curing curing agent, a siloxane hydrophobically modified epoxy and a three-dimensional rigid-flexible blend filler, a two-component compound is used to achieve fast curing, strong alkali resistance and corrosion resistance and excellent mechanical properties.

[0007] The objective of this invention can be achieved through the following technical solutions: A method for preparing a rapid-curing epoxy floor coating includes the following steps: Step 1: Add benzyldimethylamine, ethylenediamine, and thiourea to the reactor, and obtain the modified epoxy curing agent through polycondensation reaction.

[0008] Step 2: Epoxy resin E-51 is sequentially modified by etherification and ring-opening with polypropylene glycol, followed by esterification and grafting with methacrylic acid and carboxyl-terminated polydimethylsiloxane to obtain modified epoxy resin.

[0009] Step 3: Hyperbranched macromolecules are synthesized in situ using trimellitic anhydride and trimethylolpropane as monomers. The acidified polyamide is covalently bonded to lanthanum trioxide through esterification to obtain a blend filler with a three-dimensional cross-linked network structure.

[0010] Step 4: Mix the modified epoxy curing agent, defoamer, wetting agent, pigment, blended filler, anti-settling agent, deionized water and dispersant evenly to obtain component A; mix the modified epoxy resin, reactive diluent and cosolvent evenly to obtain component B; mix component A and component B evenly in a mass ratio of 1:2 to obtain a fast-curing epoxy floor coating.

[0011] The mass ratio of modified epoxy curing agent, defoamer, wetting agent, pigment, blended filler, anti-settling agent, deionized water and dispersant is 40-60:0.1-0.5:0.1-0.5:1-10:10-20:0.1-1.0:20-40:0.1-1.0.

[0012] The mass ratio of modified epoxy resin, reactive diluent, and cosolvent is 40-60:10-15:5-10.

[0013] Furthermore, the specific preparation process of the modified epoxy curing agent is as follows: Benzyl dimethylamine, ethylenediamine, and thiourea are added to a reaction vessel and reacted at 120-130℃ for 40-50 minutes. The mixture is then cooled to 50-55℃ to obtain a modified epoxy curing agent.

[0014] Furthermore, the mass ratio of benzyldimethylamine, ethylenediamine, and thiourea is 318.47-358.47: 60.10-70.10: 91.34-121.34.

[0015] Furthermore, the specific preparation process of the modified epoxy resin is as follows: Epoxy resin E-51 was added to a reactor, and a mixed solution of polypropylene glycol and tetraethylammonium bromide was added at 60-65℃. The mixture was reacted at 95-100℃ for 1-2 hours. Methacrylic acid, p-hydroxyanisole, tetraethylammonium bromide and carboxyl-terminated polydimethylsiloxane were mixed evenly at 20-25℃ and added dropwise to the reactor over 60-80 minutes. The temperature was raised to 100-110℃. After the acid value met the standard, the modified epoxy resin was obtained.

[0016] Furthermore, the mass ratio of epoxy resin E-51, polypropylene glycol, tetraethylammonium bromide, methacrylic acid, p-hydroxyanisole, and carboxyl-terminated polydimethylsiloxane is 1000-1200: 108.20-128.20: 17.30-24.30: 417.30-457.30: 0.83-0.93: 30-40.

[0017] The molecular weight of carboxyl-terminated polydimethylsiloxane is 1000-1500.

[0018] Furthermore, the specific preparation process of the blend filler is as follows: Trimeric trioxide, p-toluenesulfonic acid, and deionized water were added to a reaction vessel. Acidified polyamide was added at 140-145℃ and 300-500 r / min, and the mixture was stirred for 10-15 min. Lanthanum trioxide was then added, and the mixture was stirred for 10-15 min. Trimethylolpropane was then added, and the mixture was stirred until completely dissolved. Stirring was stopped, and the mixture was poured into a glass petri dish. The mixture was reacted at 140-150℃ and 0.7-0.8 MPa for 1-2 h. The mixture was then ground to obtain the blended filler.

[0019] Furthermore, the ratio of trimellitic anhydride, p-toluenesulfonic acid, deionized water, acidified polyamide, lanthanum trioxide, and trimethylolpropane is 80-120g: 0.2-0.5g: 600-700mL: 50-60g: 50-60g: 14-20g.

[0020] Furthermore, the specific preparation process of acidified polyamide is as follows: Maleic acid and deionized water were added to a reaction vessel, followed by polyamide. The mixture was ultrasonically stirred for 15-20 minutes and allowed to stand at 20-25°C for 24-26 hours. The mixture was then filtered under reduced pressure, washed, and dried to obtain acidified polyamide.

[0021] Furthermore, the ratio of maleic acid, deionized water, and polyamide is 1200-1600mL: 800-1200mL: 50-100g.

[0022] An epoxy floor coating based on rapid curing is obtained by uniformly mixing component A and component B in a mass ratio of 1:2.

[0023] Component A includes modified epoxy curing agent, defoamer, wetting agent, pigment, blend filler, anti-settling agent, deionized water, and dispersant.

[0024] Component B includes modified epoxy resin, reactive diluent, and cosolvent.

[0025] The beneficial effects of this invention are: 1. This invention utilizes the synergistic effect of hydrophobic modification of siloxanes and shielding by three-dimensional network blended fillers to construct a comprehensive anti-corrosion and water-resistant system from the surface to the interior. This solves the common industry problems of high water absorption, easy water vapor penetration, easy whitening and blistering under long-term high humidity, and interlayer delamination of traditional water-based epoxy floor coatings. In the preparation process of modified epoxy resin, long-chain hydrophobic flexible segments of polypropylene glycol are introduced. At the same time, Si-O-Si hydrophobic segments are introduced through esterification grafting to achieve physical hydrophobicity. Then, hyperbranched macromolecules are synthesized in situ using trimellitic anhydride-trimethylolpropane to covalently bond flexible acidified polyamide with rigid lanthanum trioxide, constructing a continuous three-dimensional cross-linked network inside the coating. This fills the micropores of the epoxy matrix, extends the penetration path of corrosive media, and prevents whitening, blistering, and delamination on damp substrates and in high-humidity environments such as underground garages, thus improving the anti-corrosion performance of epoxy floor coatings in harsh corrosive environments.

[0026] 2. This invention, through the preparation of modified epoxy curing agents and modified epoxy resins, breaks through the technical bottleneck of traditional epoxy coatings, which can only cure slowly at room temperature, cure slowly at low temperatures, and are prone to surface drying but not internal drying defects. It achieves rapid and uniform curing over a wide temperature range. Benzyl dimethylamine has high tertiary amine catalytic activity and forms a dual system of highly active amine and highly efficient catalysis with the thiourea-ethylenediamine condensation product. The thiocyanate ions generated by the high-temperature isomerization of thiourea can further activate the epoxy ring-opening and enhance the activity of the curing agent. The introduction of highly active allyl double bonds and Si-O-Si active sites into the epoxy molecule significantly improves the resin's reactivity, and the curing process is free from the defect of surface drying but not internal drying. It is fully suitable for harsh scenarios such as winter construction and tight deadlines for underground garage construction.

[0027] 3. This invention achieves a mechanical balance between flexible toughening and rigid reinforcement through the synergistic effect of modified epoxy curing agents and blended fillers. It breaks through the contradiction of traditional epoxy flooring being brittle when wear-resistant and soft when toughened. Maleic acid acidifies polyamide, and mild hydrolysis increases the carboxyl group density on the polyamide surface, resulting in a tighter bond with the resin and providing a flexible impact-resistant substrate. Then, hyperbranched macromolecules covalently bridge the flexible polyamide and rigid lanthanum trioxide. The rigid component improves hardness and wear resistance, while the flexible component absorbs impact energy. The highly active curing agent increases the crosslinking density, thereby improving impact resistance and adhesion. Detailed Implementation

[0028] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.

[0029] Example 1: This example provides a fast-curing epoxy floor coating, prepared through the following steps: S1: Add 318.47g benzyldimethylamine, 60.10g ethylenediamine and 91.34g thiourea to the reactor and react at 120℃ for 40min. Then cool down to 50℃ to obtain the modified epoxy curing agent.

[0030] Thiourea undergoes an amine condensation reaction with ethylenediamine at high temperatures. Thiourea readily transforms into its isomer, ammonium thiocyanate (NH4SCN), at high temperatures. Ammonium thiocyanate readily decomposes into thiocyanic acid (HSCN) and NH3. Ammonium thiocyanate can react with benzyldimethylamine. Ultimately, the components in epoxy curing agents can be divided into two categories: the condensation product of thiourea and ethylenediamine, where thiourea is converted into ammonium thiocyanate, and then reacts with benzyldimethylamine. Thiourea molecules have a large number of active hydrogens. Introducing thiourea into amine curing agents can not only improve the reactivity and accelerate the reaction rate, but also lower the curing temperature of amine curing agents.

[0031] S2: Add 1000g of epoxy resin E-51 to the reactor. Add a mixed solution of 108.20g of polypropylene glycol and 2.00g of tetraethylammonium bromide at 60℃ and react at 95℃ for 1h. Mix 417.30g of methacrylic acid, 0.83g of p-hydroxyanisole, 15.30g of tetraethylammonium bromide and 30g of carboxyl-terminated polydimethylsiloxane (molecular weight 1000) evenly at 20℃ and add it dropwise to the reactor over 60min. After the acid addition is complete, raise the temperature to 100℃ and measure the acid value every 1h. When the acid value is <5mgKOH / g, cool down and discharge the material to obtain the modified epoxy resin.

[0032] The hydroxyl groups of polypropylene glycol attack the epoxy groups of epoxy resin E-51 at high temperatures, undergoing a ring-opening addition reaction. This introduces flexible diethylene glycol segments into the epoxy resin backbone, disrupting the molecular chain regularity and reducing intermolecular forces, thereby reducing the viscosity and toughening of the resin. The carboxyl groups of methacrylic acid and carboxyl-terminated polydimethylsiloxane undergo esterification and ring-opening reactions with the remaining epoxy groups at high temperatures, introducing highly active allyl double bonds and Si-O-Si flexible hydrophobic segments into the resin molecules. This significantly enhances the room temperature curing reactivity of the epoxy resin. P-hydroxyanisole specifically inhibits the self-polymerization of acrylic acid double bonds, ensuring that the reaction occurs only between the carboxyl groups and epoxy groups.

[0033] S3: Add 1200mL maleic acid and 800mL deionized water to the reactor, add 50g polyamide, stir ultrasonically for 15min, let stand at 20℃ for 24h, filter under reduced pressure, wash, and dry to obtain acidified polyamide.

[0034] Using maleic acid as an acidifying agent, polyamide (PA) is acid-modified at room temperature. The H+ ions from the maleic acid ionize... + By attacking the amide bonds on the polyamide molecular chain, causing partial hydrolysis and protonation, a large number of active carboxyl groups are introduced into the polyamide surface, completing the acidification modification of the polyamide and obtaining acidified polyamide with a surface rich in reaction sites. This lays the functional group foundation for subsequent bonding reactions with hyperbranched macromolecules and inorganic fillers.

[0035] S4: Add 80g trimellitic anhydride, 0.2g p-toluenesulfonic acid and 600mL deionized water to a reaction vessel. Add 50g acidified polyamide at 140℃ and 300r / min and stir for 10min. Then add 50g lanthanum trioxide and stir for 10min. Add 14g trimethylolpropane and stir until completely dissolved. Stop stirring and pour the mixed suspension into a Φ12cm glass petri dish. Place it in a vacuum drying oven and react at 140℃ and 0.7MPa for 1h. Grind to obtain the blended filler.

[0036] Using trimellitic anhydride and trimethylolpropane as monomers and p-toluenesulfonic acid as catalyst, hyperbranched macromolecules rich in hydroxyl and carboxyl groups on the surface are synthesized in situ under high temperature conditions. The hydroxyl groups of the hyperbranched macromolecules undergo esterification with the carboxyl groups on the surface of acidified polyamide, and the carboxyl groups undergo esterification with the hydroxyl groups on the surface of lanthanum trioxide. The flexible acidified polyamide and rigid lanthanum trioxide are bonded together by covalent bonds into a homogeneous whole, forming a blend filler with a three-dimensional cross-linked network structure inside.

[0037] S5: Add 40g of modified epoxy curing agent to a dispersion tank, and add 0.1g of defoamer NY-6560, 0.1g of wetting agent NY-2177, 1g of pigment titanium dioxide, 10g of blended filler, 0.1g of anti-settling agent, 20g of deionized water and 0.1g of dispersant at 200r / min. Stir for 10min to obtain component A.

[0038] Add 40g of modified epoxy resin to a dispersion tank, add 10g of reactive diluent 1,6-hexanediol diglycidyl ether and 5g of cosolvent dipropylene glycol methyl ether at 200r / min, stir for 10min to obtain component B.

[0039] Mix component A and component B evenly at a mass ratio of 1:2 to obtain a fast-curing epoxy floor coating.

[0040] Example 2: This example provides a fast-curing epoxy floor coating, prepared through the following steps: S1: 338.47g benzyldimethylamine, 65.10g ethylenediamine and 106.34g thiourea were added to the reactor and reacted at 125℃ for 45min. The temperature was then lowered to 52℃ to obtain the modified epoxy curing agent.

[0041] S2: Add 1100g of epoxy resin E-51 to the reactor. Add a mixed solution of 118.20g of polypropylene glycol and 3.00g of tetraethylammonium bromide at 62℃ and react at 97℃ for 1.5h. Mix 437.30g of methacrylic acid, 0.88g of p-hydroxyanisole, 17.80g of tetraethylammonium bromide and 35g of carboxyl-terminated polydimethylsiloxane (molecular weight 1000) evenly at 22℃ and add it dropwise to the reactor over 70min. After the acid addition is complete, raise the temperature to 105℃ and measure the acid value every 1h. When the acid value is <5mg KOH / g, cool down and discharge the material to obtain the modified epoxy resin.

[0042] S3: Add 1400mL of maleic acid and 1000mL of deionized water to the reactor, add 75g of polyamide, stir ultrasonically for 17min, let stand at 22℃ for 25h, filter under reduced pressure, wash, and dry to obtain acidified polyamide.

[0043] S4: Add 100g trimellitic anhydride, 0.35g p-toluenesulfonic acid and 650mL deionized water to a reaction vessel. Add 55g acidified polyamide at 142℃ and 400r / min and stir for 12min. Then add 55g lanthanum trioxide and stir for 12min. Add 17g trimethylolpropane and stir until completely dissolved. Stop stirring and pour the mixed suspension into a Φ12cm glass petri dish. Place it in a vacuum drying oven and react at 145℃ and 0.75MPa for 1.5h. Grind to obtain the blended filler.

[0044] S5: Add 50g of modified epoxy curing agent to a dispersion tank, and add 0.3g of defoamer NY-6560, 0.3g of wetting agent NY-2177, 5.5g of pigment titanium dioxide, 15g of blended filler, 0.55g of anti-settling agent, 30g of deionized water and 0.55g of dispersant at 350r / min. Stir for 15min to obtain component A.

[0045] Add 50g of modified epoxy resin to a dispersion tank, add 12.5g of reactive diluent 1,6-hexanediol diglycidyl ether and 7.5g of cosolvent dipropylene glycol methyl ether at 350r / min, and stir for 15min to obtain component B.

[0046] Mix component A and component B evenly at a mass ratio of 1:2 to obtain a fast-curing epoxy floor coating.

[0047] Example 3: This example provides a fast-curing epoxy floor coating, prepared through the following steps: S1: Add 358.47g benzyldimethylamine, 70.10g ethylenediamine and 121.34g thiourea to the reactor and react at 130℃ for 50min. Then cool down to 55℃ to obtain the modified epoxy curing agent.

[0048] S2: Add 1200g of epoxy resin E-51 to the reactor. Add a mixed solution of 128.20g of polypropylene glycol and 4.00g of tetraethylammonium bromide at 65℃ and react at 100℃ for 2 hours. Mix 457.30g of methacrylic acid, 0.93g of p-hydroxyanisole, 20.30g of tetraethylammonium bromide and 40g of carboxyl-terminated polydimethylsiloxane (molecular weight 1000) evenly at 25℃ and add it dropwise to the reactor over 80 minutes. After the acid addition is complete, raise the temperature to 110℃ and measure the acid value every 1 hour. When the acid value is <5mgKOH / g, cool down and discharge the material to obtain the modified epoxy resin.

[0049] S3: Add 1600mL of maleic acid and 1200mL of deionized water to the reactor, add 100g of polyamide, stir ultrasonically for 20min, let stand at 25℃ for 26h, filter under reduced pressure, wash, and dry to obtain acidified polyamide.

[0050] S4: Add 120g trimellitic anhydride, 0.5g p-toluenesulfonic acid and 700mL deionized water to a reaction vessel. Add 60g acidified polyamide at 145℃ and 500r / min and stir for 15min. Then add 60g lanthanum trioxide and stir for 15min. Add 20g trimethylolpropane and stir until completely dissolved. Stop stirring and pour the mixed suspension into a Φ12cm glass petri dish. Place it in a vacuum drying oven and react at 150℃ and 0.8MPa for 2h. Grind to obtain the blended filler.

[0051] S5: Add 60g of modified epoxy curing agent to a dispersion tank, and add 0.5g of defoamer NY-6560, 0.5g of wetting agent NY-2177, 10g of pigment titanium dioxide, 20g of blended filler, 1.0g of anti-settling agent, 40g of deionized water and 1.0g of dispersant at 500r / min. Stir for 20min to obtain component A.

[0052] Add 60g of modified epoxy resin to a dispersion tank, add 15g of reactive diluent 1,6-hexanediol diglycidyl ether and 10g of cosolvent dipropylene glycol methyl ether at 500r / min, and stir for 20min to obtain component B.

[0053] Mix component A and component B evenly at a mass ratio of 1:2 to obtain a fast-curing epoxy floor coating.

[0054] Example 4: This example provides a fast-curing epoxy floor coating. The difference from Example 1 is that in S2, a carboxyl-terminated polydimethylsiloxane with a molecular weight of 1200 is used instead of a carboxyl-terminated polydimethylsiloxane with a molecular weight of 1000.

[0055] Example 5: This example provides a fast-curing epoxy floor coating. The difference from Example 1 is that in S2, a carboxyl-terminated polydimethylsiloxane with a molecular weight of 1500 is used instead of a carboxyl-terminated polydimethylsiloxane with a molecular weight of 1000.

[0056] Comparative Example 1: This comparative example provides a fast-curing epoxy floor coating. The difference from Example 1 is that epoxy resin E-51 is used instead of modified epoxy resin in step S5.

[0057] Comparative Example 2: This comparative example provides a fast-curing epoxy floor coating. The difference from Example 1 is that double-flying powder is used instead of blended filler in step S5.

[0058] Comparative Example 3: This comparative example provides a fast-curing epoxy floor coating, which differs from Example 1 in that the carboxyl-terminated polydimethylsiloxane is removed in step S2.

[0059] Comparative Example 4: This comparative example provides a fast-curing epoxy floor coating. The difference from Example 1 is that step S5 uses SM-650 waterborne polyamide curing agent instead of modified epoxy curing agent.

[0060] The sources of some of the raw materials involved in the above embodiments are as follows: Benzyl dimethylamine: 98% purity, purchased from Hubei Xinghengye Technology Co., Ltd.; Ethylenediamine: purity ≥98%, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Thiourea: purity ≥99%, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Epoxy resin E-51: 99% purity, purchased from Jinan Qingtian Chemical Technology Co., Ltd. Polypropylene glycol: PPG400, purity ≥99.9%, purchased from Sanda Chemical (Nantong) Co., Ltd.; Tetraethylammonium bromide: 99% purity, purchased from Wuhan Shuer Biotechnology Co., Ltd.; Maleic acid: 98% purity, purchased from Shandong Xinyingshun New Materials Co., Ltd.; Polyamide: 100% purity, purchased from Shanghai Wochengying Trading Co., Ltd. Trimeric trioxide: 99% purity, purchased from Shandong Chongcheng Energy Technology Co., Ltd.; p-Toluenesulfonic acid: 99% purity, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Lanthanum trioxide: 99.99% purity, purchased from Shandong Desheng New Materials Co., Ltd.

[0061] Carboxyl-terminated polydimethylsiloxane: molecular weight 1000-1500, custom-made, purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0062] The epoxy floor coatings based on rapid curing prepared in Examples 1-5 and Comparative Examples 1-4 were used to prepare coating films according to the requirements of GB / T22374—2018 "Floor Coating Materials" and tested. Specific test items included coating appearance, drying time, alkali resistance, and tensile bond strength. The drying time test was conducted at (23±2)℃ and 10℃. The test results are as follows: Table 1. Overview of Coating Performance Tests As shown in Table 1, the surface drying time and actual drying time of Examples 1-5 are all shorter than those of Comparative Examples 1-4, indicating that the curing speed of Examples 1-5 is faster. This may be because the fast-curing epoxy curing agent prepared in Examples 1-5 has high reactivity, the strong tertiary amine catalytic effect of benzyl dimethylamine and the thiourea-ethylenediamine condensation product synergistically improve the curing efficiency, the active hydrogen introduced by thiourea further reduces the curing activation energy, and the modified epoxy resin carries highly active allyl double bonds, which greatly increases the crosslinking rate with the curing agent, thus achieving rapid curing.

[0063] As shown in Table 1, the alkali resistance of Examples 1-5 is better than that of Comparative Examples 1-4. This may be because Examples 1-5 use carboxyl-terminated polydimethylsiloxane to hydrophobically modify the epoxy resin, thereby constructing a surface hydrophobic barrier. At the same time, the blended filler forms a three-dimensional cross-linked network to fill the micro-defects in the coating and block the penetration path of alkaline media.

[0064] After curing, the epoxy floor coatings based on rapid curing prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to performance testing: Mechanical performance testing: Refer to industry standard HG / T3829—2006 and national standard GB / T 22374—2018.

[0065] The test results are as follows: Table 2 Summary of Mechanical Performance Tests

[0066] As shown in Tables 1 and 2, the tensile bond strength and impact resistance of Examples 1-5 are higher than those of Comparative Examples 1-4, indicating that the mechanical properties of Examples 1-5 are superior. This may be because Examples 1-5 use a fast-curing epoxy curing agent to significantly increase the crosslinking density of the coating, and the modified epoxy resin is grafted with polypropylene glycol to achieve flexible toughening. The blended filler constructs a three-dimensional network structure with rigidity and flexibility through hyperbranched macromolecular covalent bonding of flexible acidified polyamide and rigid lanthanum trioxide, which not only enhances the bonding strength between the coating and the substrate and improves the hardness, but also absorbs impact energy by relying on the flexible component.

[0067] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for preparing a rapid-curing epoxy floor coating, characterized in that, Includes the following steps: Step 1: Add benzyl dimethylamine, ethylenediamine, and thiourea to the reaction vessel, and obtain the modified epoxy curing agent through polycondensation reaction; Step 2: Epoxy resin E-51 is sequentially modified by etherification and ring-opening with polypropylene glycol, followed by esterification and grafting with methacrylic acid and carboxyl-terminated polydimethylsiloxane to obtain modified epoxy resin. Step 3: Hyperbranched macromolecules are synthesized in situ using trimellitic anhydride and trimethylolpropane as monomers. The acidified polyamide is covalently bonded to lanthanum trioxide through esterification to obtain a blend filler with a three-dimensional cross-linked network structure. Step 4: Mix the modified epoxy curing agent, defoamer, wetting agent, pigment, blended filler, anti-settling agent, deionized water and dispersant evenly to obtain component A; mix the modified epoxy resin, reactive diluent and cosolvent evenly to obtain component B; mix component A and component B evenly in a mass ratio of 1:2 to obtain a fast-curing epoxy floor coating.

2. The method for preparing a rapid-curing epoxy floor coating according to claim 1, characterized in that, The mass ratio of the modified epoxy curing agent, defoamer, wetting agent, pigment, blended filler, anti-settling agent, deionized water and dispersant is 40-60:0.1-0.5:0.1-0.5:1-10:10-20:0.1-1.0:20-40:0.1-1.0; The mass ratio of the modified epoxy resin, reactive diluent, and cosolvent is 40-60:10-15:5-10.

3. The method for preparing a rapid-curing epoxy floor coating according to claim 1, characterized in that, The specific preparation process of the modified epoxy curing agent mentioned in step one is as follows: Benzyl dimethylamine, ethylenediamine and thiourea are added to a reaction vessel and reacted at 120-130℃ for 40-50 minutes. The temperature is then lowered to 50-55℃ to obtain a modified epoxy curing agent. The mass ratio of benzyldimethylamine, ethylenediamine, and thiourea is 318.47-358.47: 60.10-70.10: 91.34-121.

34.

4. The method for preparing a rapid-curing epoxy floor coating according to claim 1, characterized in that, The specific preparation process of the modified epoxy resin mentioned in step two is as follows: Epoxy resin E-51 was added to a reactor, and a mixed solution of polypropylene glycol and tetraethylammonium bromide was added at 60-65℃. The mixture was reacted at 95-100℃ for 1-2 hours. Methacrylic acid, p-hydroxyanisole, tetraethylammonium bromide and carboxyl-terminated polydimethylsiloxane were mixed evenly at 20-25℃ and added dropwise to the reactor over 60-80 minutes. The temperature was raised to 100-110℃. After the acid value met the standard, the modified epoxy resin was obtained.

5. The method for preparing a rapid-curing epoxy floor coating according to claim 4, characterized in that, The mass ratio of epoxy resin E-51, polypropylene glycol, tetraethylammonium bromide, methacrylic acid, p-hydroxyanisole, and carboxyl-terminated polydimethylsiloxane is 1000-1200: 108.20-128.20: 17.30-24.30: 417.30-457.30: 0.83-0.93: 30-40; The molecular weight of the carboxyl-terminated polydimethylsiloxane is 1000-1500.

6. The method for preparing a rapid-curing epoxy floor coating according to claim 1, characterized in that, The specific preparation process of the blended filler mentioned in step three is as follows: Trimeric trioxide, p-toluenesulfonic acid, and deionized water were added to a reaction vessel. Acidified polyamide was added at 140-145℃ and 300-500 rpm, and the mixture was stirred for 10-15 minutes. Lanthanum trioxide was then added, and the mixture was stirred for another 10-15 minutes. Trimethylolpropane was added, and the mixture was stirred until completely dissolved. Stirring was then stopped, and the mixture was poured into a glass petri dish. The reaction was carried out at 140-150℃ and 0.7-0.8 MPa for 1-2 hours. Grinding yields a blended filler.

7. The method for preparing a rapid-curing epoxy floor coating according to claim 6, characterized in that, The ratio of trimellitic anhydride, p-toluenesulfonic acid, deionized water, acidified polyamide, lanthanum trioxide, and trimethylolpropane is 80-120g: 0.2-0.5g: 600-700mL: 50-60g: 50-60g: 14-20g.

8. The method for preparing a rapid-curing epoxy floor coating according to claim 6, characterized in that, The specific preparation process of the acidified polyamide is as follows: Maleic acid and deionized water were added to a reaction vessel, followed by polyamide. The mixture was ultrasonically stirred for 15-20 minutes and allowed to stand at 20-25°C for 24-26 hours. The mixture was then filtered under reduced pressure, washed, and dried to obtain acidified polyamide.

9. The method for preparing a rapid-curing epoxy floor coating according to claim 8, characterized in that, The ratio of maleic acid, deionized water and polyamide is 1200-1600mL: 800-1200mL: 50-100g.

10. A rapid-curing epoxy floor coating, characterized in that, The epoxy floor coating is prepared by the preparation method described in any one of claims 1-9; the epoxy floor coating based on rapid curing comprises component A and component B in a mass ratio of 1:2; Component A includes a modified epoxy curing agent, a defoamer, a wetting agent, a pigment, a blend filler, an anti-settling agent, deionized water, and a dispersant; Component B includes modified epoxy resin, reactive diluent, and cosolvent.

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