Polyaspartic acid ester polyurea coating as well as preparation and use methods thereof

Abstract

The invention relates to the technical field of concrete structure protection materials, in particular to a polyaspartic acid ester polyurea coating and a preparation and use method thereof.The polyaspartic acid ester polyurea coating comprises a component A and a component B, and the mass ratio of the component A to the component B is (80-120): (70-110); wherein the component A is prepared from the following components in parts by mass: 30 to 50 parts of modified polyaspartic acid ester, 5 to 15 parts of chain extender, 1 to 5 parts of activated molecular sieve, 15 to 35 parts of body filler, 1 to 5 parts of thixotropic agent, 0.5 to 1.5 parts of defoaming agent, 0.5 to 1.5 parts of dispersing agent, 0.5 to 1.5 parts of flatting agent and 1 to 3 parts of pigment; the component B comprises the following components in parts by weight: 60-80 parts of a tripolymer curing agent and 10-30 parts of a high-activity prepolymer; the curing agent has good hydrophobicity and heat resistance, and the curing time is not influenced by a low-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete structure protective materials, and in particular to a polyaspartic acid ester polyurea coating and a preparation and use method thereof. Background Art

[0002] Concrete structures are exposed to the elements for long periods of time, and their inherent barrier capacity is limited. Under the physical and chemical erosion of the atmosphere, water, and climate, structural degradation is inevitable, resulting in a reduced service life. Therefore, it is necessary to protect the surface of concrete structures. Polyaspartic acid polyurea, as a new type of protective coating, is highly favored due to its lightweight, aesthetically pleasing, economical, easy-to-apply, and excellent performance.

[0003] Polyaspartic acid ester polyurea is a new type of aliphatic polyurea. While retaining the excellent properties of polyurea, it reduces the resin's curing rate and improves processability. It is known as the third-generation polyurea. However, because it is derived from the reaction of the secondary amino groups of polyaspartic acid ester with isocyanate, the introduction of hydrophilic groups leads to coatings that are susceptible to moisture absorption, poor hydrophobicity, and poor thermal performance. Furthermore, polyaspartic acid ester polyurea has a long pot life and a slow cure rate. Furthermore, the reaction between polyaspartic acid ester and isocyanate is much more sensitive to temperature and humidity than the reaction between hydroxypropyl resin and isocyanate. Consequently, the curing time of polyaspartic acid ester and isocyanate is significantly prolonged in low-temperature and low-humidity environments, making coating application more difficult and limiting its application.

[0004] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a polyaspartic acid ester polyurea coating and a preparation and use method thereof, which has good hydrophobicity and heat resistance and the curing time is not affected by low temperature environment.

[0006] The first object of the present invention is to provide a polyaspartic acid ester polyurea coating, which comprises a component A and a component B, wherein the mass ratio of the component A to the component B is 80-120:70-110;

[0007] Calculated by mass, component A includes:

[0008] 30-50 parts of modified polyaspartic acid ester, 5-15 parts of chain extender, 1-5 parts of activated molecular sieve, 15-35 parts of bulk filler, 1-5 parts of thixotropic agent, 0.5-1.5 parts of defoaming agent, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent and 1-3 parts of pigment;

[0009] Component B includes:

[0010] 60-80 parts of trimer curing agent and 10-30 parts of high-activity prepolymer.

[0011] As a preferred embodiment of the present invention, the modified polyaspartic acid ester is prepared by reacting ethyl trifluoromaleate with 2-mercaptoethylamine, wherein the thiol group in the 2-mercaptoethylamine does not participate in the reaction, and the primary amine is converted into a secondary amine through a Michael addition reaction;

[0012] The above equivalent SH (thiol) and secondary amine groups can ensure moderate reaction activity and avoid the polyurea coating from being too fast or too slow. At the same time, the thiol and amine groups act as bifunctional crosslinkers and can form a complex network structure with the isocyanate group to improve the overall performance of the coating.

[0013] As a preferred embodiment of the present invention, the structural formula of the modified polyaspartic acid ester is: HSCH2CH2NHCOCH(CF3)COOCH2CH3, and the molecular formula is C8H 12 F3NO3S, a modified polyaspartic acid ester, has a secondary amino group and a thiol group, both with an equivalent weight of 259.246 g / eq;

[0014] The preparation method of modified polyaspartic acid ester is as follows:

[0015] A dry 250 mL three-necked flask was equipped with a magnetic rod, a constant pressure dropping funnel and a nitrogen inlet, and nitrogen was introduced to replace the air to maintain a nitrogen atmosphere. 20 mmol of ethyl trifluoromaleate was dissolved in 50 mL of anhydrous THF and transferred to the constant pressure dropping funnel. 22 mmol of 2-mercaptoethylamine was dissolved in 30 mL of anhydrous THF and added to the three-necked flask.

[0016] Place the reaction flask in an ice bath (0°C) and stir at a rate of 100-300 rpm. Slowly add the ethyl trifluoromaleate solution dropwise. After the addition is complete, continue the reaction at 0°C for 1-2 hours, then at room temperature for 12-24 hours. After the reaction is complete, remove the solvent by vacuum rotary evaporation to obtain the modified polyaspartic acid ester.

[0017] More specifically, the reaction equation is:

[0018] C2H7NS+C6H7F3O4→C8H 12 F3NO3S+H2O;

[0019] The preparation reaction of modified polyaspartic acid ester is a nucleophilic addition reaction. Specifically, the primary amino group (NH2) of 2-mercaptoethylamine acts as a nucleophile, attacking the β-carbon atom of ethyl trifluoromaleate with a pair of lone electrons. At the same time, the π bond between the β-carbon atom and the α-carbon atom is broken, and the electron cloud is transferred to the α-carbon atom, forming a carbon anion intermediate. The carbon anion intermediate is unstable and will capture a proton from other molecules in the reaction system (such as water in the solvent or unreacted 2-mercaptoethylamine molecules) to generate the final Michael addition product.

[0020] The modified polyaspartic acid ester group contains three carbon-fluorine (CF) bonds, which have very high bond energy, making the arrangement between the molecular chains more compact and regular. When heated, this tight molecular arrangement structure can limit the movement of the molecular chains and reduce the degree of thermal motion of the molecular chains, thereby improving the heat resistance of the material; at the same time, the tight molecular arrangement also helps to prevent the transfer of heat within the material, further enhancing the heat resistance of the material.

[0021] As a preferred embodiment of the present invention, the trimer curing agent is one or more of HDI, IPDI or HMDI; HDI, IPDI or HMDI is an aliphatic trimer curing agent; the structural characteristics of the trimer curing agent used in the present invention enable the cured coating to have a high crosslinking density, giving the aspartic polyurea coating good mechanical properties; at the same time, the trimer curing agent is aliphatic, and the three-dimensional network structure formed with the modified polyaspartic acid ester can significantly improve the weather resistance of the polyurea coating, maintain the color and gloss stability of the coating in long-term outdoor environments, and resist erosion by factors such as ultraviolet rays, oxygen, and moisture.

[0022] As a preferred embodiment of the present invention, the highly active prepolymer is one or more of XDI, HDI or PDI prepolymers; the isocyanate groups in the highly active prepolymer are relatively free and do not form a stable cyclic structure like a trimer; the isocyanate groups in the highly active prepolymer have relatively small steric hindrance and high reactivity; the reactivity of the isocyanate groups mainly comes from the difference in electronegativity between nitrogen and oxygen atoms in the structure, which makes the carbon atoms carry partial positive charge and are easily attacked by nucleophilic reagents; at the same time, the highly active prepolymer is an aliphatic prepolymer, which ensures the reactivity while improving the weather resistance of the coating.

[0023] As a preferred embodiment of the present invention, the chain extender is one or more of diethylenetriamine, triethylenetetramine, or 1,4-butanediamine; the amino group in the chain extender has a relatively low electronegativity of the nitrogen atom and a weak binding force on the lone pair of electrons, making it easy for the lone pair of electrons on the amino group to attack the positively charged carbon atom in the isocyanate group in the highly reactive prepolymer, resulting in a higher reactivity than the modified polyaspartic acid ester; the highly reactive prepolymer and the chain extender can react preferentially in a targeted manner to form a polyurethane network structure while rapidly releasing heat. This heat release is global, raising the overall reaction temperature of the material, promoting the reaction between the modified polyaspartic acid ester and the trimer curing agent, and effectively increasing the reaction speed of the material at low temperatures;

[0024] More specifically, the modified polyaspartic acid ester reacts with the trimer curing agent to form an aspartic polyurea network. The thiol (-SH) group reacts preferentially with the isocyanate group in the trimer curing agent due to its stronger nucleophilicity. The reaction equation is: C8H 12 F3NO3S+C 18 H 21 N3O6→C 26 H 33 F3N4O9S; After the thiol groups in the system are completely consumed, the remaining secondary amine groups (-NH-) react with the isocyanate groups. The reaction equation is: 26 H 33 F3N4O9S+2C 18 H 21 N3O6→C 62 H 75 F3N 10 O 21 S, can significantly improve the hydrophobicity and heat resistance of polyurea coatings while ensuring a longer application period;

[0025] The highly active prepolymer reacts preferentially with the chain extender to form a polyurethane network structure. The reaction equation is: C6H 12 N2+C 16 H 26 N4O6→C 22 H 38 N6O6; The polyurethane network is interspersed in the asparagine polyurea network to form an interpenetrating network structure. This interpenetrating network structure makes the two networks intertwined with each other, producing a synergistic effect: on the one hand, the physical entanglement and interaction between the two networks increase the density and stability of the network structure, and improve the mechanical properties of the polyurea coating, such as strength and toughness; on the other hand, the two networks have different chemical compositions and structures, and each has unique performance advantages. The hydrophobicity and heat resistance of the asparagine polyurea network are combined with the structural characteristics of the polyurethane network, so that the polyurea coating can exhibit better comprehensive performance under different environmental conditions.

[0026] As a preferred embodiment of the present invention, the activated molecular sieve is one or more of 3A, 4A or 5A activated molecular sieves; the use of activated molecular sieves can directionally adsorb moisture in the material or construction environment, so that the polyurea coating can fully react to form a more complete and dense cross-linked structure, thereby improving the mechanical properties and durability of the coating; at the same time, the activated molecular sieve can also ensure that the performance of the coating is stable during storage.

[0027] As a preferred embodiment of the present invention, the physical filler is one or more of carbonates, silicates or metal oxides, preferably microsilica powder, magnesium carbonate, and zinc oxide; the physical filler can play a role in heat insulation and high temperature resistance in the polyurea coating, improve the thermal stability of the coating, enable it to maintain good performance in a high temperature environment, and reduce the occurrence of thermal deformation and thermal aging; at the same time, the physical filler can fill the tiny pores and defects on the surface of the coated object, making the coating smoother, improving the adhesion and hiding power of the coating to the substrate, and reducing the amount of coating used.

[0028] As a preferred embodiment of the present invention, the thixotropic agent is one or more of fumed silica, organic bentonite or polyamide wax; the thixotropic agent can improve the construction performance, increase the structural viscosity to prevent sagging when at rest, and reduce the viscosity when subjected to shear force to facilitate coating, thereby ensuring uniform coating and efficient construction; during storage, the thixotropic agent can prevent precipitation and stratification, and the three-dimensional network structure formed by the thixotropic agent wraps the pigment and filler to prevent sedimentation, maintain the uniform dispersion of the various components of the coating, and extend the storage period.

[0029] As a preferred embodiment of the present invention, the defoamer is an organosilicon defoamer, including one or more of polysiloxane, modified polysiloxane or polysiloxane containing hydrophobic particles, preferably polysiloxane defoamer BYK141, modified polysiloxane defoamer BYK-A525 and polysiloxane defoamer BYK093 containing hydrophobic particles; the hydrophilic groups of the organosilicon defoamer interact with liquid molecules, reduce the surface tension of the liquid, and quickly release bubbles from the liquid; the lipophilic groups adsorb on the surface of the bubbles, hinder gas aggregation, inhibit bubble generation, effectively eliminate mechanical bubbles generated during the mixing process of the coating, and avoid defects in the material due to excessive bubbles, thereby affecting the mechanical properties of the coating.

[0030] Furthermore, the dispersant is one or more of anionic, cationic or nonionic, preferably anionic dispersant BYK110, cationic dispersant BYK109 and nonionic dispersant BYK102; the dispersant can reduce the viscosity of the system, improve the dispersion efficiency of pigments and fillers, prevent particle agglomeration and sedimentation, enhance the wettability of pigments and fillers, and improve the gloss, hiding power and stability of the coating.

[0031] Furthermore, the leveling agent is a silicone leveling agent, which is one or more of polyether-modified silicone, alkyl-modified silicone or fluorine-modified silicone, preferably polyether-modified silicone leveling agent BYK320, alkyl-modified silicone leveling agent BYK323 and fluorine-modified silicone leveling agent SF334; the molecules of the silicone leveling agent contain silicon-oxygen bonds, with the methyl groups arranged outward, and can quickly migrate to the surface of the coating. By virtue of its low surface free energy, it reduces the surface tension of the coating, promotes better spreading of the coating, and achieves leveling; at the same time, it can reduce the contact angle between the coating and the substrate, improve the adhesion to the substrate, and improve the wettability of pigments and fillers; it can form a weak network structure in the coating, which is destroyed by shear force during construction, and the coating has good fluidity, which is convenient for construction and leveling. After construction, the network is restored to prevent sagging and accurately control the rheology.

[0032] Furthermore, the pigment is an inorganic gray pigment, preferably carbon black, iron oxide gray, or ultramarine gray; the pigment used in the present invention has a high-purity gray tone, good light resistance and weather resistance, and excellent tinting strength and hiding power.

[0033] A second object of the present invention is to provide a method for preparing a polyaspartic acid ester polyurea coating, comprising:

[0034] Adding modified polyaspartic acid ester, chain extender, thixotropic agent, defoamer, dispersant and leveling agent, and dispersing uniformly to obtain a mixture M;

[0035] Adding activated molecular sieve, bulk filler and pigment to the mixture M and dispersing them evenly to obtain component A;

[0036] The trimer curing agent and the highly reactive prepolymer are uniformly dispersed to obtain component B;

[0037] The components A and B are mixed evenly to obtain a polyaspartic acid ester polyurea coating.

[0038] Furthermore, the preparation method of component A is as follows:

[0039] Place the modified polyaspartic acid ester in a reactor with a stirring speed of 800-1000 r / min. After heating to 60-80°C, add a chain extender, a defoamer, a dispersant, a leveling agent and a thixotropic agent, stir for 30 minutes, add activated molecular sieves, physical fillers and pigments, stir for 60 minutes, and cool to room temperature to obtain component A.

[0040] Furthermore, the preparation method of component B is as follows:

[0041] Place the trimer curing agent and high-activity prepolymer in a reaction kettle, stir at a speed of 500-800 r / min, heat to 60-80°C, stir for 60 minutes, and cool to room temperature to obtain component B.

[0042] The preparation method of the present invention is carried out at 60-80°C and normal pressure, without the need for high temperature and high pressure conditions. The mild environment can avoid the decomposition and failure of components such as the modified polyaspartic acid ester sulfhydryl group, thereby ensuring the stable performance of each component; at the same time, it reduces equipment requirements and energy consumption, simplifies process operations, improves production safety and economy, and is conducive to industrial promotion.

[0043] A third object of the present invention is to provide a method for using a polyaspartic acid ester polyurea coating, comprising:

[0044] Mix component A and component B according to the mass ratio and spray evenly on the surface of the concrete structure.

[0045] Further, pour component A into the A barrel of the polyurea sprayer, stir at a speed of 500 r / min, stir for 50 to 60 seconds, stir evenly, and set aside;

[0046] Further, pour component B into the B barrel of the polyurea sprayer, stir at a speed of 500 r / min, stir for 30 to 40 seconds, stir evenly, and set aside;

[0047] Furthermore, component A and component B are evenly sprayed on the surface of the concrete structure using a polyurea sprayer nozzle, with a spraying speed of 10 to 30 g / s and a cross-linking and curing time of 60 to 120 minutes.

[0048] The method for using the polyaspartic acid ester polyurea coating of the present invention is simple and easy to operate, does not require complicated manual mixing, has a uniform and efficient spraying process, has a moderate cross-linking and curing time, can quickly form a film, significantly improves construction efficiency, is suitable for coating large-area concrete surfaces, and has both construction convenience and engineering practicality.

[0049] Compared with the prior art, the present invention has the following advantages: 1) the thiol group in the modified polyaspartic acid ester provided by the present invention can react with the isocyanate in the highly active prepolymer to form a relatively stable thiourea structure. The reaction equation is: HSCH2CH2NHCOCH(CF3)CH2COOCH2CH3+OCN(CH2)6NCO→S(CO-NH(CH2)6NCO)CH2CH2NHCOCH(CF3)CH2COOCH2CH3. The electronegativity of the sulfur atom in the thiourea group is 0. The larger the size of the fluorine atoms, the more electronegative they are, and the smaller the size of the fluorine atoms. This will change the distribution of electron clouds on the molecular surface, forming an effect similar to that of sulfur-containing hydrophobic groups, reducing the attraction to water molecules. At the same time, the fluorine atoms in the CF bonds have extremely high electronegativity, which makes the fluorine-containing groups have a strong electron-withdrawing ability. The presence of fluorine atoms changes the distribution of electron cloud density on the molecular surface, weakens the intermolecular forces, and reduces the surface energy. At the same time, fluorine atoms form a microstructure similar to the "lotus effect" on the surface of the material, so that water molecules can only form weak van der Waals forces with the fluorine atoms on the surface of the material, significantly improving the hydrophobicity of the material.

[0050] 2) The isocyanate groups in the highly active prepolymer provided by the present invention are relatively free, with relatively little steric hindrance, and thus have a higher reactivity than the trimer curing agent. The amino groups in the chain extender have relatively low electronegativity in their nitrogen atoms, resulting in weak binding force on lone pairs of electrons, allowing the lone pairs of electrons on the amino groups to easily attack the positively charged carbon atoms in the isocyanate, resulting in a higher reactivity than the modified polyaspartic acid ester. The preferential directional reaction between the two can quickly release heat, increase the overall reaction temperature of the material, promote the reaction between the modified polyaspartic acid ester and the trimer curing agent, and effectively increase the reaction speed of the material in a low-temperature environment.

[0051] 3) The modified polyaspartic acid ester in the moisture-heat-resistant polyaspartic acid ester polyurea coating provided by the present invention reacts with the trimer curing agent to form an aspartic acid polyurea network, which can significantly improve the hydrophobicity and heat resistance of the polyurea coating while ensuring a long application period; and the high-activity prepolymer and the chain extender react preferentially with each other to form a polyurethane network structure, and provide high reaction heat to promote the formation of the aspartic acid polyurea network under low temperature conditions. The polyurethane network is interspersed in the aspartic acid polyurea network to form an interpenetrating network structure, producing a synergistic effect, which can greatly improve the performance of the polyurea coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 Schematic diagram of the interpenetrating synergistic effect between the aspartic acid polyurea network and the polyurethane network formed after the reaction of the modified polyaspartic acid ester and the trimer curing agent in Example 2 of the present invention;

[0053] Figure 2 Schematic diagram of the effect of the reaction between modified polyaspartic acid ester and trimer curing agent in Example 2 of the present invention to improve hydrophobicity and heat resistance;

[0054] Figure numerals: 1, aspartame network structure; 2, polyurethane network structure; 3, thiourea structure; 4, carbon-fluorine (CF) group. DETAILED DESCRIPTION

[0055] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0056] The sources of raw materials used in this specific embodiment are as follows:

[0057] Ethyl trifluoromaleate: Shanghai Furui Fine Chemical Co., Ltd.;

[0058] 2-Mercaptoethylamine: Jiujiang Huirong Chemical Co., Ltd.

[0059] Trimer curing agent: HT-100, Wanhua Chemical Group Co., Ltd.; Z4470, Desmodur W, Covestro AG;

[0060] Highly reactive prepolymers: Takenate 500, D-3725N, Mitsui Chemicals, Inc.; SC7930, LANXESS Chemical (China) Co., Ltd.

[0061] Chain extenders: diethylenetriamine, triethylenetetramine, Shandong Mingsheng Chemical Technology Co., Ltd.; 1,4-butanediamine, Shanghai Aladdin Biochemical Technology Co., Ltd.

[0062] Activated molecular sieves: 3A activated molecular sieve, 4A activated molecular sieve, 5A activated molecular sieve, Jiangxi Heyuan Environmental Protection New Materials Co., Ltd.;

[0063] Physical fillers: microsilica fume, Shandong Boken Silicon Materials Co., Ltd.; magnesium carbonate, Lianyungang Guansu Industrial Co., Ltd.; zinc oxide, Shandong Yousuo Chemical Technology Co., Ltd.

[0064] Thixotropic agent: R972, Evonik Specialty Chemicals Co., Ltd.; BP-186, Guangzhou Zhenwei Chemical Technology Co., Ltd.; OPTIMA, Arkema (China) Investment Co., Ltd.

[0065] Defoaming agents: BYK-A525, BYK141, BYK093, BYK Chemical Company, Germany;

[0066] Dispersants: BYK110, BYK109, BYK102, BYK Chemical Company, Germany;

[0067] Leveling agent: BYK320, BYK323, BYK Chemical Company of Germany; SF334, Xiamen Aikema Chemical Co., Ltd.

[0068] Pigments: MA100, 5008, Shanghai Jinghong Chemical Technology Co., Ltd.; 686, Shanghai Shenhong Pigment Co., Ltd.;

[0069] Low-activity prepolymer: H2122A, Jining Sunbright Biotechnology Co., Ltd.

[0070] Unmodified polyaspartic acid ester: NH1420, Covestro Polymers (China) Co., Ltd.

[0071] Example 1:

[0072] The heat-resistant polyaspartic acid ester polyurea coating provided in this embodiment is composed of component A and component B, which are mixed in a mass ratio of 80:70. Calculated by mass, component A includes:

[0073] 30 parts of modified polyaspartic acid ester, 5 parts of diethylenetriamine, 1 part of 3A activated molecular sieve, 15 parts of magnesium carbonate, 1 part of R972, 0.5 parts of BYK-A525, 0.5 parts of BYK110, 0.5 parts of BYK320, 1 part of MA100;

[0074] Component B includes: 60 parts HT-100, 10 parts Takenate 500.

[0075] The present embodiment provides a method for preparing a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0076] S1. Place 30 parts of modified polyaspartic acid ester in a reactor, stir at a stirring speed of 800 r / min, heat to 60°C, add 1 part of R972, 0.5 parts of BYK-A525, 0.5 parts of BYK110 and 0.5 parts of BYK320, stir for 30 minutes, add 1 part of 3A activated molecular sieve, 15 parts of magnesium carbonate and 1 part of MA100, stir for 60 minutes, and cool to room temperature to obtain component A;

[0077] S2. Place 60 parts of HT-100 and 10 parts of Takenate 500 in a reactor, heat to 60°C, stir at a speed of 500 r / min, stir for 60 minutes, and cool to room temperature to obtain component B;

[0078] The preparation method of modified polyaspartic acid ester is as follows: add a magnet to a dry 250mL three-necked flask, assemble a constant pressure dropping funnel and a nitrogen tube, introduce nitrogen to replace the air, and maintain a nitrogen environment. Dissolve 20mmol of ethyl trifluoromaleate in 50mL of anhydrous THF and transfer it to a constant pressure dropping funnel. Dissolve 22mmol of 2-mercaptoethylamine in 30mL of anhydrous THF and add it to the three-necked flask. Place the reaction flask in an ice bath (0℃) and stir at a stirring rate of 100r / min, and slowly add the ethyl trifluoromaleate solution dropwise. After the addition is complete, continue to react at 0℃ for 1 hour, and then react at room temperature for 12 hours. After the reaction is completed, remove the solvent by vacuum rotary evaporation to obtain modified polyaspartic acid ester.

[0079] The present embodiment provides a method for using a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0080] P1. Pour component A into the A barrel of the polyurea sprayer, stir at a speed of 500 r / min for 50 seconds, stir evenly, and set aside;

[0081] P2. Pour component B into the B barrel of the polyurea sprayer, stir at a speed of 500r / min for 30s, stir evenly, and set aside;

[0082] P3. The slurry obtained from P1 and P2 was mixed at a mass ratio of 80:70 at a high speed through the nozzle of a polyurea sprayer, and sprayed evenly on the surface of the concrete structure at a spraying speed of 10g / s. The repair was completed after cross-linking and curing for 60 minutes.

[0083] The following performance tests were performed to obtain the data in Table 1:

[0084] Table 1: Performance indicators of the asparagus polyurea coating in Example 1

[0085]

[0086] In the above tests: hydrophobicity is mainly evaluated by two indicators: contact angle and water absorption rate;

[0087] Heat resistance test method: Place the aspartame polyurea coating in a blast oven, heat it at 80°C for 14 days, cool it to room temperature and condition it for 16 hours, test its tensile properties, and evaluate its heat resistance by tensile strength retention and elongation at break;

[0088] The tensile strength retention rate is the ratio of the tensile strength of the coating film before heating to the tensile strength of the coating film after heating.

[0089] Example 2:

[0090] The heat-resistant polyaspartic acid ester polyurea coating provided in this embodiment is composed of component A and component B, which are mixed in a mass ratio of 100:90. Calculated by mass, component A includes:

[0091] 40 parts modified polyaspartic acid ester, 10 parts triethylenetetramine, 3 parts 4A activated molecular sieve, 25 parts microsilica fume, 3 parts BP186, 1 part BYK141, 1 part BYK109, 1 part BYK323, 2 parts 5008;

[0092] Component B includes: 70 parts Z4470, 20 parts D-3725N.

[0093] The present embodiment provides a method for preparing a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0094] S1. Place 40 parts of modified polyaspartic acid ester in a reactor, stir at a stirring speed of 900 r / min, heat to 70°C, add 10 parts of triethylenetetramine, 3 parts of BP186, 1 part of BYK141, 1 part of BYK109, and 1 part of BYK323, stir for 30 minutes, add 3 parts of 4A activated molecular sieve, 25 parts of microsilica powder and 2 parts of 5008, stir for 60 minutes, and cool to room temperature to obtain component A;

[0095] S2. Place 70 parts of Z4470 and 20 parts of D-3725N in a reactor, heat to 70°C, stir at a speed of 650 r / min, stir for 60 minutes, and cool to room temperature to obtain component B;

[0096] The preparation method of modified polyaspartic acid ester is as follows: add a magnet to a dry 250mL three-necked flask, assemble a constant pressure dropping funnel and a nitrogen tube, introduce nitrogen to replace the air, and maintain a nitrogen environment. Dissolve 20mmol of ethyl trifluoromaleate in 50mL of anhydrous THF and transfer it to a constant pressure dropping funnel. Dissolve 22mmol of 2-mercaptoethylamine in 30mL of anhydrous THF and add it to the three-necked flask. Place the reaction flask in an ice bath (0℃) and stir at a stirring rate of 200r / min, and slowly add the ethyl trifluoromaleate solution dropwise. After the addition is complete, continue to react at 0℃ for 1.5 hours, and then react at room temperature for 18 hours. After the reaction is completed, remove the solvent by vacuum rotary evaporation to obtain modified polyaspartic acid ester.

[0097] The present embodiment provides a method for using a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0098] P1. Pour component A into the A barrel of the polyurea sprayer, stirring at a speed of 500 r / min for 55 seconds, stir evenly, and set aside;

[0099] P2. Pour component B into the B barrel of the polyurea sprayer, stir at a speed of 500 r / min for 35 seconds, stir evenly, and set aside;

[0100] P3. The slurries obtained from P1 and P2 were mixed at a mass ratio of 100:90 through the nozzle of a polyurea sprayer at high speed, and sprayed evenly on the surface of the concrete structure at a spraying speed of 20g / s. The repair was completed after cross-linking and curing for 90 minutes.

[0101] The following performance tests were performed to obtain the data in Table 2:

[0102] Table 2: Performance indicators of the asparagus polyurea coating in Example 2

[0103]

[0104] Example 3:

[0105] The heat-resistant polyaspartic acid ester polyurea coating provided in this embodiment is composed of component A and component B, which are mixed in a mass ratio of 120:110. Calculated by mass, component A includes:

[0106] 50 parts of modified polyaspartic acid ester, 15 parts of 1,4-butanediamine, 5 parts of 5A activated molecular sieve, 35 parts of zinc oxide, 5 parts of OPTIMA, 1.5 parts of BYK093, 1.5 parts of BYK102, 1.5 parts of SF334, 3 parts of 686;

[0107] Component B includes: 80 parts of Desmodur W and 30 parts of SC7930.

[0108] The present embodiment provides a method for preparing a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0109] S1. Place 50 parts of modified polyaspartic acid ester in a reactor, stir at a stirring speed of 1000 r / min, heat to 80°C, add 5 parts of OPTIMA, 1.5 parts of BYK093, 1.5 parts of BYK102, and 1.5 parts of SF334, stir for 30 minutes, add 5 parts of 5A activated molecular sieve, 35 parts of zinc oxide and 3 parts of 686, stir for 60 minutes, and cool to room temperature to obtain component A.

[0110] S2. Place 80 parts of Desmodur W and 30 parts of SC7930 in a reactor, heat to 80°C, stir at a speed of 800 r / min, stir for 60 minutes, and cool to room temperature to obtain component B.

[0111] The preparation method of modified polyaspartic acid ester is as follows: add a magnet to a dry 250mL three-necked flask, assemble a constant pressure dropping funnel and a nitrogen tube, introduce nitrogen to replace the air, and maintain a nitrogen environment. Dissolve 20mmol of ethyl trifluoromaleate in 50mL of anhydrous THF and transfer it to a constant pressure dropping funnel. Dissolve 22mmol of 2-mercaptoethylamine in 30mL of anhydrous THF and add it to the three-necked flask. Place the reaction flask in an ice bath (0℃) and stir at a stirring rate of 300r / min, and slowly add the ethyl trifluoromaleate solution dropwise. After the addition is complete, continue to react at 0℃ for 2 hours, and then react at room temperature for 24 hours. After the reaction is completed, remove the solvent by vacuum rotary evaporation to obtain modified polyaspartic acid ester.

[0112] The present embodiment provides a method for using a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0113] P1. Pour component A into the A barrel of the polyurea sprayer, stir at a speed of 500 r / min for 60 seconds, stir evenly, and set aside;

[0114] P2. Pour component B into the B barrel of the polyurea sprayer, stir at a speed of 500r / min for 40s, stir evenly, and set aside;

[0115] P3. The slurry obtained from P1 and P2 was mixed at a mass ratio of 120:110 at a high speed through the nozzle of a polyurea sprayer, and sprayed evenly on the surface of the concrete structure at a spraying speed of 30g / s. The repair was completed after cross-linking and curing for 120 minutes.

[0116] The following performance tests were performed to obtain the data in Table 3:

[0117] Table 3: Performance indicators of aspartame polyurea coating in Example 3

[0118]

[0119] Comparative Example 1:

[0120] The heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is composed of component A and component B, which are mixed in a mass ratio of 100:90; calculated by mass, component A includes:

[0121] 40 parts NH1420, 10 parts triethylenetetramine, 3 parts 4A activated molecular sieve, 25 parts microsilica fume, 3 parts BP186, 1 part BYK141, 1 part BYK109, 1 part BYK323, 2 parts 5008;

[0122] Component B includes: 70 parts Z4470, 20 parts D-3725N.

[0123] The present embodiment provides a method for preparing a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0124] S1. Place 40 parts of NH1420 in a reactor, stir at a speed of 900 r / min, heat to 70°C, add 10 parts of triethylenetetramine, 3 parts of BP186, 1 part of BYK141, 1 part of BYK109, and 1 part of BYK323, stir for 30 minutes, add 3 parts of 4A activated molecular sieve, 25 parts of microsilica powder and 2 parts of 5008, stir for 60 minutes, and cool to room temperature to obtain component A.

[0125] S2. Place 70 parts of Z4470 and 20 parts of D-3725N in a reactor, heat to 70°C, stir at a speed of 650 r / min, stir for 60 minutes, and cool to room temperature to obtain component B.

[0126] The method of using the moisture-heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is the same as that in Example 2.

[0127] The following performance tests were performed to obtain the data in Table 4:

[0128] Table 4: Performance indicators of aspartame polyurea coating in Comparative Example 1

[0129]

[0130] Compared with Example 2, only unmodified polyaspartic acid ester NH1420 was added to Comparative Example 1, but triethylenetetramine and D-3725N were added. From the data, the contact angle of the aspartic polyurea coating was significantly reduced, the water absorption rate increased from 1.2% in Example 2 to 5.6%, the tensile strength retention rate was only 75%, and the elongation at break was reduced by 78%, indicating that there are no thiol groups and fluorine-containing groups in the structure of the unmodified NH1420, and it is impossible to react with the curing agent to form a thiourea group with good hydrophobicity and a CF bond with strong heat resistance; the surface drying time and the actual drying time are comparable to those in Example 2, indicating that the heat released by the reaction of triethylenetetramine and D-3725N can significantly shorten the reaction time under low temperature conditions.

[0131] Comparative Example 2:

[0132] The heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is composed of component A and component B, which are mixed in a mass ratio of 100:90; calculated by mass, component A includes:

[0133] 40 parts modified polyaspartic acid ester, 3 parts 4A activated molecular sieve, 25 parts microsilica fume, 3 parts BP186, 1 part BYK141, 1 part BYK109, 1 part BYK323, 2 parts 5008;

[0134] Component B includes: 70 parts of Z4470.

[0135] The present embodiment provides a method for preparing a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0136] S1. Place 40 parts of modified polyaspartic acid ester in a reactor, stir at a stirring speed of 900 r / min, heat to 70°C, add 3 parts of BP186, 1 part of BYK141, 1 part of BYK109, and 1 part of BYK323, stir for 30 minutes, add 3 parts of 4A activated molecular sieve, 25 parts of microsilica powder and 2 parts of 5008, stir for 60 minutes, and cool to room temperature to obtain component A.

[0137] S2. Place 70 parts of Z4470 in a reactor, heat to 70°C, stir at a speed of 650 r / min, stir for 60 minutes, and cool to room temperature to obtain component B.

[0138] The preparation method of modified polyaspartic acid ester is as follows: add a magnet to a dry 250mL three-necked flask, assemble a constant pressure dropping funnel and a nitrogen tube, introduce nitrogen to replace the air, and maintain a nitrogen environment. Dissolve 20mmol of ethyl trifluoromaleate in 50mL of anhydrous THF and transfer it to a constant pressure dropping funnel. Dissolve 22mmol of 2-mercaptoethylamine in 30mL of anhydrous THF and add it to the three-necked flask. Place the reaction flask in an ice bath (0℃) and stir at a stirring rate of 200r / min, and slowly add the ethyl trifluoromaleate solution dropwise. After the addition is complete, continue to react at 0℃ for 1.5 hours, and then react at room temperature for 18 hours. After the reaction is completed, remove the solvent by vacuum rotary evaporation to obtain modified polyaspartic acid ester.

[0139] The method of using the moisture-heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is the same as that in Example 2.

[0140] The following performance tests were performed to obtain the data in Table 5:

[0141] Table 5: Performance indicators of aspartame polyurea coating in comparative example 2

[0142]

[0143] Compared with Example 2, Comparative Example 2 added modified polyaspartic acid ester, but did not add triethylenetetramine and D-3725N. From the data, the contact angle, water absorption, tensile strength retention, and elongation at break of the coating were all comparable to those in Example 2, indicating that the thiourea groups generated by the reaction of the modified polyaspartic acid ester with the curing agent can reduce the attraction to water and improve the hydrophobicity of the coating; the C-F bonds therein can reduce the degree of thermal motion of the molecular chain, significantly improving the heat resistance of the coating; and the curing speed of the coating at low temperatures is greatly prolonged, with the surface dry time and through dry time extended to 12 hours and 24 hours, respectively. This indicates that although the modified polyaspartic acid ester improves the hydrophobicity and heat resistance, it lacks the high heat released by the reaction of triethylenetetramine and D-3725N to provide a reaction environment, resulting in the system still having the problem of slow reaction at low temperatures.

[0144] Comparative Example 3:

[0145] The heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is composed of component A and component B, which are mixed in a mass ratio of 100:90; calculated by mass, component A includes:

[0146] 40 parts NH1420, 3 parts 4A activated molecular sieve, 25 parts microsilica fume, 3 parts BP186, 1 part BYK141, 1 part BYK109, 1 part BYK323, 2 parts 5008;

[0147] Component B includes: 70 parts of Z4470.

[0148] The present embodiment provides a method for preparing a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0149] S1. Place 40 parts of NH1420 in a reactor, stir at a speed of 900 r / min, heat to 70°C, add 3 parts of BP186, 1 part of BYK141, 1 part of BYK109, and 1 part of BYK323, stir for 30 minutes, add 3 parts of 4A activated molecular sieve, 25 parts of microsilica powder and 2 parts of 5008, stir for 60 minutes, and cool to room temperature to obtain component A.

[0150] S2. Place 70 parts of Z4470 in a reactor, heat to 70°C, stir at a speed of 650 r / min, stir for 60 minutes, and cool to room temperature to obtain component B.

[0151] The method of using the moisture-heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is the same as that in Example 2.

[0152] The following performance tests were performed to obtain the data in Table 6:

[0153] Table 6: Performance indicators of aspartame polyurea coating in comparative example 3

[0154]

[0155] Compared with Example 2, in Comparative Example 3, modified polyaspartic acid ester, triethylenetetramine, and D-3725N were not added. From the data, the curing time of the coating at low temperature was greatly extended, indicating that the lack of high heat released by the reaction of triethylenetetramine and D-3725N to provide the system reaction temperature resulted in a slow reaction rate of the coating at low temperature; the contact angle of the coating was only 60°, and the water absorption rate increased to 5.9%, indicating that the absence of thiourea groups in the reaction product of unmodified NH1420 and curing agent increased the attraction of the coating to water, resulting in poor hydrophobicity; through heat resistance test comparison, the tensile strength retention rate of the coating dropped to 65%, and the elongation at break decreased to 102%, indicating that the absence of C-F bonds in unmodified NH1420 could not restrict the thermal motion of the molecular chain, resulting in poor heat resistance.

[0156] Comparative Example 4:

[0157] The heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is composed of component A and component B, which are mixed in a mass ratio of 100:90; calculated by mass, component A includes:

[0158] 40 parts modified polyaspartic acid ester, 10 parts triethylenetetramine, 3 parts 4A activated molecular sieve, 25 parts microsilica fume, 3 parts BP186, 1 part BYK141, 1 part BYK109, 1 part BYK323, 2 parts 5008;

[0159] Component B includes: 70 parts Z4470, 20 parts H2122A.

[0160] The present embodiment provides a method for preparing a moisture-heat-resistant polyaspartic acid ester polyurea coating, comprising the following steps:

[0161] S1. Place 40 parts of modified polyaspartic acid ester in a reactor, stir at a speed of 900 r / min, heat to 70°C, add 10 parts of triethylenetetramine, 3 parts of BP186, 1 part of BYK141, 1 part of BYK109, and 1 part of BYK323, stir for 30 minutes, add 3 parts of 4A activated molecular sieve, 25 parts of microsilica powder and 2 parts of 5008, stir for 60 minutes, and cool to room temperature to obtain component A.

[0162] S2. Place 70 parts of Z4470 and 20 parts of H2122A in a reactor, heat to 70°C, stir at a speed of 650 r / min, stir for 60 minutes, and cool to room temperature to obtain component B.

[0163] The preparation method of modified polyaspartic acid ester is as follows: add a magnet to a dry 250mL three-necked flask, assemble a constant pressure dropping funnel and a nitrogen tube, introduce nitrogen to replace the air, and maintain a nitrogen environment. Dissolve 20mmol of ethyl trifluoromaleate in 50mL of anhydrous THF and transfer it to a constant pressure dropping funnel. Dissolve 22mmol of 2-mercaptoethylamine in 30mL of anhydrous THF and add it to the three-necked flask. Place the reaction flask in an ice bath (0℃) and stir at a stirring rate of 200r / min, and slowly add the ethyl trifluoromaleate solution dropwise. After the addition is complete, continue to react at 0℃ for 1.5 hours, and then react at room temperature for 18 hours. After the reaction is completed, remove the solvent by vacuum rotary evaporation to obtain modified polyaspartic acid ester.

[0164] The method of using the moisture-heat-resistant polyaspartic acid ester polyurea coating provided in this comparative example is the same as that in Example 2.

[0165] The following performance tests were performed to obtain the data in Table 7:

[0166] Table 7: Performance indicators of the aspartame polyurea coating in Comparative Example 4:

[0167]

[0168]

[0169] Compared with Example 2, Comparative Example 4 incorporated a modified polyaspartic acid ester, but no high-reactivity prepolymer, and only the low-reactivity prepolymer H2122A. The data showed that the coating's low-temperature curing time was somewhat shorter than when the high-reactivity prepolymer was added, but the overall reaction rate remained relatively slow, with a dry time exceeding 20 hours. The coating's contact angle, water absorption, tensile strength retention, and elongation at break were comparable to those in Example 2, indicating that the sulfhydryl groups and C—F bonds in the modified polyaspartic acid ester significantly improved the coating's hydrophobicity and heat resistance in the reaction system.

[0170] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A polyaspartic acid ester polyurea coating, characterized in that: The polyaspartic acid ester polyurea coating comprises component A and component B, wherein the mass ratio of component A to component B is 80-120:70-110; Wherein, calculated by mass, the A component includes: 30-50 parts of modified polyaspartic acid ester, 5-15 parts of chain extender, 1-5 parts of activated molecular sieve, 15-35 parts of bulk filler, 1-5 parts of thixotropic agent, 0.5-1.5 parts of defoaming agent, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent and 1-3 parts of pigment; The B component includes: 60-80 parts of trimer curing agent and 10-30 parts of high-activity prepolymer.

2. The polyaspartic acid ester polyurea coating according to claim 1, wherein The modified polyaspartic acid ester is prepared by reacting ethyl trifluoromaleate with 2-mercaptoethylamine, and the primary amine of 2-mercaptoethylamine is converted into a secondary amine through a Michael addition reaction.

3. The polyaspartic acid ester polyurea coating according to claim 1, characterized in that: The trimer curing agent is one or more of HDI, IPDI or HMDI.

4. The polyaspartic acid ester polyurea coating according to claim 1, wherein The highly active prepolymer is one or more of XDI, HDI or PDI prepolymers.

5. The polyaspartic acid ester polyurea coating according to claim 1, characterized in that: The chain extender is one or more of diethylenetriamine, triethylenetetramine or 1,4-butanediamine.

6. The polyaspartic acid ester polyurea coating according to claim 1, characterized in that: The activated molecular sieve is one or more of 3A, 4A or 5A activated molecular sieves.

7. The polyaspartic acid ester polyurea coating according to claim 1, characterized in that: The physical filler is one or more of carbonate, silicate or metal oxide.

8. The polyaspartic acid ester polyurea coating according to claim 1, characterized in that: The thixotropic agent is one or more of fumed silica, organic bentonite or polyamide wax.

9. The method for preparing the polyaspartic acid ester polyurea coating according to any one of claims 1 to 8, characterized in that: include: adding the modified polyaspartic acid ester, the chain extender, the thixotropic agent, the defoamer, the dispersant and the leveling agent, and dispersing them uniformly to obtain a mixture M; Adding the activated molecular sieve, the physical filler and the pigment to the mixture M and dispersing them evenly to obtain component A; uniformly dispersing the trimer curing agent and the highly active prepolymer to obtain component B; The component A and the component B are mixed evenly to obtain the polyaspartic acid ester polyurea coating.

10. The method for using the polyaspartic acid ester polyurea coating according to claim 9, wherein: include: The component A and the component B are mixed according to a mass ratio and sprayed evenly on the surface of the concrete structure.

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