A crack-resistant and wear-resistant paint and its preparation method

Abstract

This invention relates to the field of composite material technology and discloses a crack-resistant and wear-resistant paint and its preparation method. The method includes pretreatment of fillers, preparation of modified resin matrix, grinding of dispersing aids, crosslinking and curing stages, and aging treatment. By plasma activation treatment of ceramic microspheres, the surface activity of the filler is enhanced, and its interfacial compatibility with the resin matrix is ​​improved, avoiding early cracking of the coating due to poor interfacial bonding. At the same time, the activated filler and nano-alumina form a gradient-dispersed reinforcing network structure in the matrix, improving the overall density and wear resistance of the coating. A composite system of epoxy-modified acrylic resin and polyurethane prepolymer is used. Through the reaction of isocyanate curing agents with the active groups in the resin during the crosslinking and curing stage, a stable structure is formed, enhancing the toughness and adhesion of the paint film, thereby inhibiting cracking and peeling of the coating during use.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, specifically to a crack-resistant and wear-resistant paint and its preparation method. Background Technology

[0002] Paint is a chemical mixture that can firmly cover the surface of an object, serving as a protective, decorative, marking, and other special-purpose coating. It is named after the fact that people originally used vegetable oil as the main raw material to produce paint. Paint is a viscous oily pigment that is flammable when undried. It is insoluble in water, slightly soluble in fats, soluble in alcohols, aldehydes, ethers, benzene, and alkanes, and readily soluble in gasoline, kerosene, and diesel oil. Regardless of its type or form, paint is composed of three basic substances: film-forming substances, secondary film-forming substances, and auxiliary film-forming substances.

[0003] Currently, paint production involves a variety of raw materials and complex processes. When preparing crack-resistant and wear-resistant paints, conventional filler treatment methods are difficult to effectively improve the interfacial bonding strength between the filler and the resin matrix. If the filler surface is not activated, it may lead to uneven dispersion of the filler in the matrix or insufficient interfacial bonding force, which can easily cause early cracking of the coating or a decrease in wear resistance, and cannot guarantee the long-term durability of the paint.

[0004] Therefore, a crack-resistant and wear-resistant paint and its preparation method are proposed to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a crack-resistant and wear-resistant paint and its preparation method, which solves the problem mentioned in the background technology that uneven dispersion of fillers in the matrix or insufficient interfacial bonding force can easily lead to early cracking of the coating or a decrease in wear resistance, thus failing to guarantee the long-term durability of the paint.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a crack-resistant and wear-resistant paint, comprising the following steps:

[0007] Step 1: Pretreatment of the filler material. Select ceramic microspheres with a particle size of 50-80 micrometers and place them in a plasma treatment device under a vacuum of 1×10⁻⁶. -2 Up to 1×10 -3 Under conditions of Pa and power of 400-600W, argon gas is introduced for 10-20 minutes to obtain activated ceramic microspheres;

[0008] Step 2: Prepare the modified resin matrix. Add 60-80 parts of epoxy modified acrylic resin and 20-30 parts of polyurethane prepolymer to the reactor. Under nitrogen protection, heat to 70-80℃ and stir at 300-500r / min for 30-40 minutes.

[0009] Step 3: Grinding the dispersing agent. Mix 15-25 parts of activated ceramic microspheres, 5-10 parts of nano alumina, and 0.5-1 parts of defoamer obtained in Step 1 with the modified resin matrix obtained in Step 2. Use a three-roll mill to grind the mixture 3-5 times under a roller gap pressure of 0.3-0.5MPa until the fineness is ≤20 micrometers.

[0010] Step 4: Crosslinking and curing stage. Add 2-4% of the total mass of isocyanate curing agent to the grinding product and stir at a low speed of 200-300 r / min at 40-50℃ for 15-25 minutes, while controlling the viscosity at 800-1200 cps.

[0011] Step 5: Maturation treatment. Transfer the product to a sealed container and let it stand at 25-30℃ for 24-48 hours, stirring at 60r / min for 5 minutes every 6 hours.

[0012] Preferably, the pretreatment of ceramic microspheres in step one further includes a preliminary purification process, specifically:

[0013] The ceramic microspheres were first soaked in hydrofluoric acid solution for 1-2 hours, then rinsed with deionized water until neutral, dried at 110℃ for 2 hours, and then subjected to plasma treatment.

[0014] The concentration of the hydrofluoric acid solution is 4.5-5.5%, and ultrasonic assisted treatment is used during soaking, with an ultrasonic frequency of 40kHz and a power of 200W.

[0015] Preferably, in step two, the epoxy-modified acrylic resin has an epoxy value of 0.08-0.12 eq / 100g and a hydroxyl value of 50-70 mg KOH / g;

[0016] The NCO content of the polyurethane prepolymer is 6-8%, and the polyurethane prepolymer is prepared by reacting toluene diisocyanate and polyether polyol at 70-80℃ for 3-5 hours.

[0017] Preferably, the nano-alumina in step three has a particle size of 30-50 nm, a specific surface area of ​​≥150 m² / g, and is surface-treated with silane coupling agent KH-550 before use at a temperature of 80°C for 1 hour.

[0018] The defoamer is a modified polysiloxane compound with a viscosity of 200-400 mPa·s. It is added in three equal portions, with a 10-minute interval between each addition.

[0019] Preferably, the isocyanate curing agent in step four is a mixture of HDI trimer and IPDI trimer, with a mass ratio of 1:1 to 1:2. When adding it, it needs to be diluted to a concentration of 50% with propylene glycol methyl ether acetate beforehand, and allowed to stand for 30 minutes to remove bubbles after dilution.

[0020] Preferably, during the curing process in step five, viscosity changes need to be monitored. When the viscosity fluctuation exceeds the initial value ±10%, the curing time is extended by 12 hours and the stirring frequency is increased to once every 4 hours. The humidity of the curing environment is controlled at 40-60%.

[0021] Preferably, the roller temperature of the three-roll mill is 25-35℃, and the roller surface residue is cleaned after each cycle during the grinding process to ensure uniform grinding.

[0022] Preferably, in step two, the nitrogen protection flow rate is 10-15 L / min, the pressure inside the reactor is maintained at 0.1-0.2 MPa, the stirring paddle has an anchor structure, and the gap between the paddle blade and the reactor wall is 5-10 mm.

[0023] A crack-resistant and abrasion-resistant paint, the composition of which, by weight, comprises:

[0024] The ingredients are: 60-80 parts epoxy-modified acrylic resin, 20-30 parts polyurethane prepolymer, 15-25 parts activated ceramic microspheres, 5-10 parts nano alumina, 0.5-1 part defoamer, and isocyanate curing agent.

[0025] Preferably, the activated ceramic microspheres and nano-alumina form a gradient-dispersed reinforced network structure after the paint is cured, wherein the nano-alumina fills the gaps between the ceramic microspheres and forms chemical bonds with the resin matrix through a silane coupling agent.

[0026] Compared with the prior art, the present invention provides a crack-resistant and wear-resistant paint and its preparation method, which has the following beneficial effects:

[0027] 1. In this invention, by performing plasma activation treatment on ceramic microspheres, the surface activity of the filler is enhanced, the interfacial compatibility between the filler and the resin matrix is ​​improved, and the early cracking of the coating caused by poor interfacial bonding is avoided. At the same time, the activated filler and nano alumina form a gradient-dispersed reinforced network structure in the matrix, thereby improving the overall density and wear resistance of the coating.

[0028] 2. In this invention, a composite system of epoxy-modified acrylic resin and polyurethane prepolymer is used. During the cross-linking and curing stage, isocyanate curing agents react with the active groups in the resin to form a stable structure, which enhances the toughness and adhesion of the paint film, thereby inhibiting cracking and peeling of the coating during use.

[0029] 3. In this invention, by controlling the roller gap pressure and the number of cycles of the three-roll mill, the filler is ensured to be uniformly dispersed in the resin matrix to achieve the specified fineness, avoiding local stress concentration caused by particle agglomeration or uneven dispersion, thereby improving the impact resistance and surface smoothness of the coating; by combining the process of static setting and stirring, the components of the system are fully diffused and the subsequent reaction is completed, eliminating internal stress and improving the chemical stability and physical property consistency of the coating system. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1: A method for preparing a crack-resistant and wear-resistant paint, comprising the following steps:

[0032] Step 1: Pretreatment of the filler material. Select ceramic microspheres with a particle size of 50 micrometers and place them in a plasma treatment device under a vacuum of 1×10⁻⁶. -2 Under the conditions of Pa and power of 400W, argon gas was introduced for 10 minutes to obtain activated ceramic microspheres;

[0033] Step 2: Prepare the modified resin matrix. Add 60 parts of epoxy modified acrylic resin and 20 parts of polyurethane prepolymer to the reactor, heat to 70°C under nitrogen protection, and stir and mix at 300 r / min for 30 minutes.

[0034] Step 3: Grinding the dispersing agent. Mix 15 parts of activated ceramic microspheres, 5 parts of nano alumina, and 0.5 parts of defoamer obtained in Step 1 with the modified resin matrix obtained in Step 2. Grind the mixture three times using a three-roll mill at a roller gap pressure of 0.3 MPa until the fineness is ≤20 micrometers.

[0035] Step 4: Crosslinking and curing stage. Add 2% isocyanate curing agent of the total mass of the system to the grinding product, stir at 200 r / min at 40℃ for 15 minutes, and control the viscosity at 800 cps.

[0036] Step 5: Maturation treatment. Transfer the product to a sealed container and let it stand at 25°C for 24 hours, stirring at 60 r / min for 5 minutes every 6 hours.

[0037] The pretreatment of ceramic microspheres in step one also includes a preliminary purification process, specifically:

[0038] The ceramic microspheres were first soaked in hydrofluoric acid solution for 1 hour, then rinsed with deionized water until neutral, dried at 110°C for 2 hours, and then subjected to plasma treatment.

[0039] The hydrofluoric acid solution concentration was 4.5%, and ultrasonic assisted treatment was used during soaking, with an ultrasonic frequency of 40kHz and a power of 200W.

[0040] In step two, the epoxy value of the epoxy-modified acrylic resin is 0.08 eq / 100g, and the hydroxyl value is 50 mg KOH / g.

[0041] The NCO content of the polyurethane prepolymer is 6%, and the polyurethane prepolymer is prepared by reacting toluene diisocyanate and polyether polyol at a mass ratio of 1:1.2 at 70°C for 3 hours.

[0042] In step three, the nano-alumina has a particle size of 30nm, a specific surface area of ​​≥150m² / g, and is surface-treated with silane coupling agent KH-550 before use at a temperature of 80℃ for 1 hour.

[0043] The defoamer is a modified polysiloxane compound with a viscosity of 200 mPa·s. It is added in three equal portions, with a 10-minute interval between each addition.

[0044] In step four, the isocyanate curing agent is a mixture of HDI trimer and IPDI trimer in a mass ratio of 1:1. When adding it, it needs to be diluted to a concentration of 50% with propylene glycol methyl ether acetate beforehand, and then allowed to stand for 30 minutes to remove bubbles.

[0045] During the curing process in step five, viscosity changes need to be monitored. When the viscosity fluctuation exceeds ±10% of the initial value, the curing time should be extended by 12 hours and the stirring frequency should be increased to once every 4 hours. The humidity of the curing environment should be controlled at 40%.

[0046] The roller temperature of the three-roll mill is 25℃. After each cycle during the grinding process, the residue on the roller surface is cleaned to ensure uniform grinding.

[0047] In step two, the nitrogen protection flow rate is 10 L / min, the pressure inside the reactor is maintained at 0.1 MPa, the agitator is an anchor-type structure, and the gap between the agitator blade and the reactor wall is 5 mm.

[0048] A crack-resistant and abrasion-resistant paint, the composition of which, by weight, comprises:

[0049] The mixture consists of 60 parts epoxy-modified acrylic resin, 20 parts polyurethane prepolymer, 15 parts activated ceramic microspheres, 5 parts nano-alumina, 0.5 parts defoamer, and isocyanate curing agent.

[0050] After the paint is cured, activated ceramic microspheres and nano-alumina form a gradient-dispersed reinforced network structure, in which nano-alumina fills the gaps between ceramic microspheres and forms chemical bonds with the resin matrix through a silane coupling agent.

[0051] Example 2: A method for preparing a crack-resistant and wear-resistant paint, comprising the following steps:

[0052] Step 1: Pretreatment of the filler material. Select ceramic microspheres with a particle size of 70 micrometers and place them in a plasma treatment device under a vacuum of 1×10⁻⁶. -2 Under the conditions of Pa and 500W power, argon gas was introduced for 15 minutes to obtain activated ceramic microspheres;

[0053] Step 2: Prepare the modified resin matrix. Add 70 parts of epoxy modified acrylic resin and 25 parts of polyurethane prepolymer to the reactor, heat to 75°C under nitrogen protection, and stir and mix at 400 r / min for 35 minutes.

[0054] Step 3: Grinding the dispersing agent. Mix 20 parts of activated ceramic microspheres, 7 parts of nano alumina, and 0.7 parts of defoamer obtained in Step 1 with the modified resin matrix obtained in Step 2. Grind the mixture 4 times using a three-roll mill at a roller gap pressure of 0.4 MPa until the fineness is ≤20 micrometers.

[0055] Step 4: Crosslinking and curing stage. Add 3% isocyanate curing agent of the total mass of the system to the grinding product, and stir at a low speed of 250r / min at 45℃ for 20 minutes, while controlling the viscosity at 1000cps.

[0056] Step 5: Maturation treatment. Transfer the product to a sealed container and let it stand at 28°C for 36 hours, stirring at 60 r / min for 5 minutes every 6 hours.

[0057] The pretreatment of ceramic microspheres in step one also includes a preliminary purification process, specifically:

[0058] The ceramic microspheres were first soaked in hydrofluoric acid solution for 1.5 hours, then rinsed with deionized water until neutral, dried at 110°C for 2 hours, and then subjected to plasma treatment.

[0059] The hydrofluoric acid solution concentration was 5.0%, and ultrasonic assisted treatment was used during soaking, with an ultrasonic frequency of 40kHz and a power of 200W.

[0060] In step two, the epoxy-modified acrylic resin has an epoxy value of 0.10 eq / 100g and a hydroxyl value of 60 mg KOH / g.

[0061] The NCO content of the polyurethane prepolymer is 7%, and the polyurethane prepolymer is prepared by reacting toluene diisocyanate and polyether polyol at a mass ratio of 1:1.5 at 75°C for 4 hours.

[0062] In step three, the nano-alumina has a particle size of 40nm, a specific surface area of ​​≥150m² / g, and is surface-treated with silane coupling agent KH-550 before use at a temperature of 80℃ for 1 hour.

[0063] The defoamer is a modified polysiloxane compound with a viscosity of 300 mPa·s. It is added in three equal portions, with a 10-minute interval between each addition.

[0064] In step four, the isocyanate curing agent is a mixture of HDI trimer and IPDI trimer in a mass ratio of 1:1.5. When adding it, it needs to be diluted to a concentration of 50% with propylene glycol methyl ether acetate beforehand, and then allowed to stand for 30 minutes to degas.

[0065] During the curing process in step five, viscosity changes need to be monitored. When the viscosity fluctuation exceeds ±10% of the initial value, the curing time is extended by 12 hours and the stirring frequency is increased to once every 4 hours. The humidity of the curing environment is controlled at 50%.

[0066] The roller temperature of the three-roll mill is 30℃. After each cycle during the grinding process, the residue on the roller surface is cleaned to ensure uniform grinding.

[0067] In step two, the nitrogen protection flow rate is 13 L / min, the pressure inside the reactor is maintained at 0.15 MPa, the agitator is an anchor-type structure, and the gap between the agitator blade and the reactor wall is 7 mm.

[0068] A crack-resistant and abrasion-resistant paint, the composition of which, by weight, comprises:

[0069] 70 parts epoxy-modified acrylic resin, 25 parts polyurethane prepolymer, 20 parts activated ceramic microspheres, 7 parts nano alumina, 0.7 parts defoamer, and isocyanate curing agent.

[0070] After the paint is cured, activated ceramic microspheres and nano-alumina form a gradient-dispersed reinforced network structure, in which nano-alumina fills the gaps between ceramic microspheres and forms chemical bonds with the resin matrix through a silane coupling agent.

[0071] Example 3: A method for preparing a crack-resistant and wear-resistant paint, comprising the following steps:

[0072] Step 1: Pretreatment of the filler material. Select ceramic microspheres with a particle size of 80 micrometers and place them in a plasma treatment device under a vacuum of 1×10⁻⁶. -3 Under the conditions of Pa and power of 600W, argon gas was introduced for 20 minutes to obtain activated ceramic microspheres;

[0073] Step 2: Prepare the modified resin matrix. Add 80 parts of epoxy modified acrylic resin and 30 parts of polyurethane prepolymer to the reactor. Heat to 80°C under nitrogen protection and stir at 500 r / min for 40 minutes.

[0074] Step 3: Grinding the dispersing agent. Mix 25 parts of activated ceramic microspheres, 10 parts of nano alumina, and 1 part of defoamer obtained in Step 1 with the modified resin matrix obtained in Step 2. Grind the mixture 5 times using a three-roll mill at a roller gap pressure of 0.5 MPa until the fineness is ≤20 micrometers.

[0075] Step 4: Crosslinking and curing stage. Add 4% isocyanate curing agent of the total mass of the system to the grinding product, stir at 300 r / min at 50℃ for 25 minutes, and control the viscosity at 1200 cps.

[0076] Step 5: Maturation treatment. Transfer the product to a sealed container and let it stand at 30°C for 48 hours, stirring at 60 r / min for 5 minutes every 6 hours.

[0077] The pretreatment of ceramic microspheres in step one also includes a preliminary purification process, specifically:

[0078] The ceramic microspheres were first soaked in hydrofluoric acid solution for 2 hours, then rinsed with deionized water until neutral, dried at 110°C for 2 hours, and then subjected to plasma treatment.

[0079] The hydrofluoric acid solution concentration was 5.5%, and ultrasonic assisted treatment was used during soaking, with an ultrasonic frequency of 40kHz and a power of 200W.

[0080] In step two, the epoxy value of the epoxy-modified acrylic resin is 0.12 eq / 100g, and the hydroxyl value is 70 mg KOH / g.

[0081] The NCO content of the polyurethane prepolymer is 8%, and the polyurethane prepolymer is prepared by reacting toluene diisocyanate and polyether polyol at a mass ratio of 1:1.8 at 80°C for 5 hours.

[0082] In step three, the nano-alumina has a particle size of 50nm, a specific surface area of ​​≥150m² / g, and is surface-treated with silane coupling agent KH-550 before use at a temperature of 80℃ for 1 hour.

[0083] The defoamer is a modified polysiloxane compound with a viscosity of 400 mPa·s. It is added in three equal portions, with a 10-minute interval between each addition.

[0084] In step four, the isocyanate curing agent is a mixture of HDI trimer and IPDI trimer in a mass ratio of 1:2. When adding it, it needs to be diluted to a concentration of 50% with propylene glycol methyl ether acetate beforehand, and then allowed to stand for 30 minutes to remove bubbles.

[0085] During the curing process in step five, viscosity changes need to be monitored. When the viscosity fluctuation exceeds ±10% of the initial value, the curing time should be extended by 12 hours and the stirring frequency should be increased to once every 4 hours. The humidity of the curing environment should be controlled at 60%.

[0086] The roller temperature of the three-roll mill is 35℃. After each cycle during the grinding process, the residue on the roller surface is cleaned to ensure uniform grinding.

[0087] In step two, the nitrogen protection flow rate is 15 L / min, the pressure inside the reactor is maintained at 0.2 MPa, the agitator is an anchor-type structure, and the gap between the agitator blade and the reactor wall is 10 mm.

[0088] A crack-resistant and abrasion-resistant paint, the composition of which, by weight, comprises:

[0089] 80 parts epoxy-modified acrylic resin, 30 parts polyurethane prepolymer, 25 parts activated ceramic microspheres, 10 parts nano alumina, 1 part defoamer, and isocyanate curing agent.

[0090] After the paint is cured, activated ceramic microspheres and nano-alumina form a gradient-dispersed reinforced network structure, in which nano-alumina fills the gaps between ceramic microspheres and forms chemical bonds with the resin matrix through a silane coupling agent.

[0091] Comparative Example 1: The difference between this comparative example and Example 1 is that the ceramic microspheres were not subjected to plasma activation treatment during the preparation of the paint in this comparative example, and the original ceramic microspheres were used directly.

[0092] Comparative Example 2 differs from Example 1 in that nano-alumina was not added during the preparation of the paint in this comparative example.

[0093] Comparative Example 3 differs from Example 1 in that: this comparative example does not use a composite matrix of epoxy-modified acrylic resin and polyurethane prepolymer, but only uses a single epoxy resin as the film-forming substance.

[0094] Comparative Example 4 differs from Example 1 in that the curing process is omitted in this comparative example, and the grinding is carried out directly.

[0095] The performance of the crack-resistant and wear-resistant paints prepared in Examples 1-3 and Comparative Examples 1-4 was tested. The test items and test methods are as follows:

[0096] Adhesion testing was conducted using the cross-cut test method, employing a cross-cut tester with a cut spacing of 2 mm.

[0097] Abrasion resistance test: using a rubber grinding wheel, the mass loss was calculated under a 500g load and 500 revolutions.

[0098] Impact resistance testing is conducted using an impact tester.

[0099] The flexibility test was conducted using a shaft bending tester to evaluate the crack resistance of the paint film.

[0100] The test data of the crack-resistant and wear-resistant paints prepared in Examples 1-3 and Comparative Examples 1-4 are recorded in the table below:

[0101] Group Adhesion test (grade) Mass loss (g) Impact resistance (kg·cm) Minimum bending diameter (mm) Example 1 Level 1 0.02g 50kg·cm 2mm Example 2 Level 0 0.015g 55kg·cm 2mm Example 3 Level 0 0.01g 60kg·cm 1mm Comparative Example 1 Level 3 0.05g 30kg·cm 4mm Comparative Example 2 Level 2 0.04g 40kg·cm 3mm Comparative Example 3 Level 4 0.06g 20kg·cm 6mm Comparative Example 4 Level 2 0.03g 45kg·cm 3mm

[0102] By comparing and analyzing the data in the table, it can be seen that the crack-resistant and wear-resistant paints prepared using the processes in Examples 1-3 have significantly better performance than the paints prepared using the processes in Comparative Examples 1-4. This indicates that the present invention enhances the surface activity of the filler by plasma activation treatment of ceramic microspheres, improves its interfacial compatibility with the resin matrix, and avoids early cracking of the coating due to weak interfacial bonding. At the same time, the activated filler and nano-alumina form a gradient-dispersed reinforcing network structure in the matrix, improving the overall density and wear resistance of the coating. The composite system of epoxy-modified acrylic resin and polyurethane prepolymer, through isocyanate... During the cross-linking and curing stage, ester-based curing agents react with active groups in the resin to form a stable structure, enhancing the toughness and adhesion of the paint film and thus inhibiting cracking and peeling during use. By controlling the roller gap pressure and cycle number of the three-roll mill, the filler is ensured to be uniformly dispersed in the resin matrix to achieve the specified fineness, avoiding local stress concentration caused by particle agglomeration or uneven dispersion, and improving the impact resistance and surface smoothness of the coating. Through a process combining static and stirring, the components of the system are fully diffused and the subsequent reaction is completed, eliminating internal stress and improving the chemical stability and physical property consistency of the coating system.

[0103] By comparing and analyzing the relevant data in the table, it can be seen that the anti-crack and wear-resistant paint prepared by the process of the present invention has excellent wear resistance, crack resistance, adhesion and hardness.

[0104] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "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. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0105] 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, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a crack-resistant and wear-resistant paint, characterized in that: Includes the following steps: Step 1: Pretreatment of the filler material. Select ceramic microspheres with a particle size of 50-80 micrometers and place them in a plasma treatment device under a vacuum of 1×10⁻⁶. -2 Up to 1×10 -3 Under conditions of Pa and power of 400-600W, argon gas is introduced for 10-20 minutes to obtain activated ceramic microspheres; Step 2: Prepare the modified resin matrix. Add 60-80 parts of epoxy modified acrylic resin and 20-30 parts of polyurethane prepolymer to the reactor. Under nitrogen protection, heat to 70-80℃ and stir at 300-500r / min for 30-40 minutes. Step 3: Grinding the dispersing agent. Mix 15-25 parts of activated ceramic microspheres, 5-10 parts of nano alumina, and 0.5-1 parts of defoamer obtained in Step 1 with the modified resin matrix obtained in Step 2. Use a three-roll mill to grind the mixture 3-5 times under a roller gap pressure of 0.3-0.5MPa until the fineness is ≤20 micrometers. Step 4: Crosslinking and curing stage. Add 2-4% of the total mass of isocyanate curing agent to the grinding product and stir at a low speed of 200-300 r / min at 40-50℃ for 15-25 minutes, while controlling the viscosity at 800-1200 cps. Step 5: Maturation treatment. Transfer the product to a sealed container and let it stand at 25-30℃ for 24-48 hours, stirring at 60r / min for 5 minutes every 6 hours.

2. The method for preparing a crack-resistant and wear-resistant paint according to claim 1, characterized in that: The pretreatment of ceramic microspheres in step one also includes a preliminary purification process, specifically: The ceramic microspheres were first soaked in hydrofluoric acid solution for 1-2 hours, then rinsed with deionized water until neutral, dried at 110℃ for 2 hours, and then subjected to plasma treatment. The concentration of the hydrofluoric acid solution is 4.5-5.5%, and ultrasonic assisted treatment is used during soaking, with an ultrasonic frequency of 40kHz and a power of 200W.

3. The method for preparing a crack-resistant and wear-resistant paint according to claim 1, characterized in that: In step two, the epoxy-modified acrylic resin has an epoxy value of 0.08-0.12 eq / 100g and a hydroxyl value of 50-70 mg KOH / g. The NCO content of the polyurethane prepolymer is 6-8%, and the polyurethane prepolymer is prepared by reacting toluene diisocyanate and polyether polyol at 70-80℃ for 3-5 hours.

4. The method for preparing a crack-resistant and wear-resistant paint according to claim 1, characterized in that: In step three, the nano-alumina has a particle size of 30-50nm, a specific surface area of ​​≥150m² / g, and is surface-treated with silane coupling agent KH-550 before use at a temperature of 80℃ for 1 hour. The defoamer is a modified polysiloxane compound with a viscosity of 200-400 mPa·s. It is added in three equal portions, with a 10-minute interval between each addition.

5. The method for preparing a crack-resistant and wear-resistant paint according to claim 1, characterized in that: In step four, the isocyanate curing agent is a mixture of HDI trimer and IPDI trimer in a mass ratio of 1:1 to 1:

2. When adding it, it needs to be diluted to a concentration of 50% with propylene glycol methyl ether acetate beforehand, and allowed to stand for 30 minutes to remove bubbles after dilution.

6. The method for preparing a crack-resistant and wear-resistant paint according to claim 1, characterized in that: During the curing process in step five, viscosity changes need to be monitored. When the viscosity fluctuation exceeds ±10% of the initial value, the curing time is extended by 12 hours and the stirring frequency is increased to once every 4 hours. The humidity of the curing environment is controlled at 40-60%.

7. The method for preparing a crack-resistant and wear-resistant paint according to claim 1, characterized in that: The roller temperature of the three-roll mill is 25-35℃. After each cycle during the grinding process, the residue on the roller surface is cleaned to ensure uniform grinding.

8. The method for preparing a crack-resistant and wear-resistant paint according to claim 1, characterized in that: In step two, the nitrogen protection flow rate is 10-15 L / min, the pressure inside the reactor is maintained at 0.1-0.2 MPa, the stirring paddle has an anchor structure, and the gap between the paddle blade and the reactor wall is 5-10 mm.

9. A crack-resistant and wear-resistant paint, prepared by the method for preparing a crack-resistant and wear-resistant paint according to any one of claims 1-8, characterized in that: The paint consists of the following components by weight: The ingredients are: 60-80 parts epoxy-modified acrylic resin, 20-30 parts polyurethane prepolymer, 15-25 parts activated ceramic microspheres, 5-10 parts nano alumina, 0.5-1 part defoamer, and isocyanate curing agent.

10. The crack-resistant and wear-resistant paint according to claim 9, characterized in that: The activated ceramic microspheres and nano-alumina form a gradient-dispersed reinforced network structure after the paint is cured, wherein the nano-alumina fills the gaps between the ceramic microspheres and forms chemical bonds with the resin matrix through a silane coupling agent.