A patching agent, its preparation method and use

Abstract

The present application belongs to the technical field of repair agent, and particularly relates to a repair agent, a preparation method and application thereof. The repair agent comprises component A and component B. The component A comprises 100-150 parts by weight of aliphatic epoxy resin, 100-150 parts by weight of metal ceramic powder, 50-100 parts by weight of anti-sulfur toughening alloy powder and 30-80 parts by weight of low-friction self-lubricating powder. The component B comprises 40-60 parts by weight of curing agent. The repair agent has good flexibility, self-lubricating property, processability, good anti-sulfur corrosion capacity, strong bonding strength and internal bonding strength. After curing, the repair agent has very stable bonding strength in slurry containing sulfur corrosion and chlorine ion corrosion, and the cured structure still maintains high strength even in a slurry environment at 70 DEG C.

Description

Technical Field

[0001] This invention belongs to the field of repair agent technology, specifically relating to a repair agent, its preparation method, and its application. Background Technology

[0002] Surface engineering, as an important means of maintenance, has received increasing attention. As an important part of the discipline of surface engineering, surface technology includes electroplating, brush plating, thermal spraying, and adhesive coating. These repair methods complement each other and have become necessary emergency measures for equipment maintenance. They repair scrapped parts, bring old parts back to life, and save enterprises from huge economic losses. Equipment maintenance has become an integral part of productivity.

[0003] Compared with surface coating technology, welding, thermal spraying and electroplating, surface coating technology is simpler. It does not require special equipment or consume heat and electricity. Simply apply the prepared repair agent to the cleaned surface to be repaired. After curing, it is as hard as metal and can be machined in various ways to meet the maintenance needs of parts such as wear resistance, corrosion resistance, dimensional restoration, defect filling, and sealing.

[0004] Metal repair compound is a key technology for surface coating and bonding in equipment maintenance. It is a putty-like composite material widely used for wear and corrosion resistance repair and pre-protective coating of parts, as well as for repairing various defects of parts (such as cracks, scratches, dimensional deviations, casting porosity, sand holes) and sealing leaks. The process is simple and easy to implement. Just mix the two components of the composite material evenly in proportion, apply it to the rust-removed and degreased surface, and then touch up after curing. It is a labor-saving, time-saving, economical, durable, flexible, convenient and ideal new repair material, and is one of the fastest developing composite materials at present. Summary of the Invention

[0005] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0006] Epoxy repair putty, prepared from resin and solid powder fillers (e.g., alumina powder, silicon carbide powder, brown corundum powder), is a traditional repair material on the market, used to fill cracks, repair damaged metal surfaces, and bond various materials. Due to the limitations of the inherent properties of resin and the limitations of solid powder fillers, traditional epoxy repair agents on the market have the following problems: (1) high brittleness; (2) poor self-lubricating properties; (3) poor processability; (4) limited adaptability to substrates and low bonding strength.

[0007] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a repair agent that possesses good flexibility, self-lubricating properties, processability, good resistance to sulfur corrosion, and strong bonding and internal bonding strength. After curing, this repair agent exhibits very stable bonding strength in slurries containing sulfur and chloride ions, and the cured structure maintains high strength even in a slurry environment at 70°C.

[0008] The repair agent of this invention includes component A and component B. Component A includes 100-150 parts by weight of aliphatic epoxy resin, 100-150 parts by weight of cermet powder, 50-100 parts by weight of sulfur-resistant toughening alloy powder and 30-80 parts by weight of low-friction self-lubricating powder. Component B includes 40-60 parts by weight of curing agent.

[0009] The advantages and technical effects of the repair agent in this invention are as follows: 1. In this invention, an aliphatic epoxy resin with good flexibility is used, which makes the repair agent perform better in dealing with thermal expansion, contraction and mechanical stress; 2. In this invention, low-friction self-lubricating powder is added to the repair agent, so that after the repair agent is applied to the surface of the flow part, it becomes smoother with the scouring of the fluid, and the wear resistance and toughness are also very good; 3. In this invention, a solid particle filler composed of metal ceramic powder and sulfur-resistant toughening alloy powder is used in conjunction with the epoxy resin system. This solid filler has the toughness of metal and the high hardness of ceramic, and it does not damage the cutting tool during processing, and can produce a smooth and delicate machined surface, with very good processing performance; 4. In this invention, alloy powder with good sulfur corrosion resistance is added, which greatly improves the sulfur corrosion resistance of the repair agent in the sulfur-containing slurry environment; 5. In this invention, the repair agent can be cured at room temperature or under heating conditions according to the temperature, humidity and other conditions of the repair site, and the curing time can be controlled to 1-12 hours, which is convenient for construction operations.

[0010] In some embodiments, the cermet powder includes at least one of WC-Ni, WC-Co, Cr3C2-Ni, and Cr3C2-Co; the sulfur-resistant toughening alloy powder includes at least one of NiCr alloy, NiCrTi alloy, and Inconel 625 alloy; and the low-friction self-lubricating powder includes at least one of TiN, SiN, and BN.

[0011] In some embodiments, the curing agent comprises a polyamide curing agent.

[0012] In some embodiments, the repair agent further includes at least one of a diluent, a toughening agent, a defoamer, a pigment, and a leveling agent.

[0013] This invention also provides a method for preparing the repair agent, comprising the following steps:

[0014] (1) Component A: Prepare aliphatic epoxy resin, and then add metal ceramic powder, sulfur-resistant toughening alloy powder and low-friction self-lubricating powder;

[0015] (2) Component B: Prepare curing agent.

[0016] The advantages and technical effects of the preparation method of this invention are as follows: 1. The method of this invention, by configuring components A and B respectively, can avoid premature reaction between the curing agent and the aliphatic epoxy resin, resulting in gel hardening of the repair agent and inability to carry out construction operations; 2. The method of this invention is simple and easy to operate, and is convenient for promotion and application in industrial production.

[0017] In some embodiments, step (1) further includes immersing the metal ceramic powder, sulfur-resistant toughened alloy powder, and low-friction self-lubricating powder in an alkaline solution for etching treatment before adding them to an aliphatic epoxy resin.

[0018] In some embodiments, the alkaline solution is NaOH with a mass fraction of 20-50%; the etching temperature is 30-70°C; and the etching time is 20-45 min.

[0019] In some embodiments, step (1) further includes adding an auxiliary agent, which includes at least one of a diluent, a toughening agent, a defoamer, a pigment, and a leveling agent.

[0020] In some embodiments, in step (2), the curing agent is a polyamide curing agent, and the preparation of the polyamide curing agent includes: reacting the amide and the acid anhydride at 100-120°C and 101.3-121.56 kPa for 4-6 hours.

[0021] The application of the repair agent of the present invention or the repair agent prepared by the preparation method of the present invention in a sulfur-containing slurry environment. Detailed Implementation

[0022] The repair agent of this invention includes component A and component B. Component A includes 100-150 parts by weight of aliphatic epoxy resin, 100-150 parts by weight of cermet powder, 50-100 parts by weight of sulfur-resistant toughening alloy powder and 30-80 parts by weight of low-friction self-lubricating powder. Component B includes 40-60 parts by weight of curing agent.

[0023] The repair agent of this invention uses aliphatic epoxy resin with good flexibility, which makes the repair agent perform better in the face of thermal expansion, contraction and mechanical stress. Low-friction self-lubricating powder is added to the repair agent, so that after the repair agent is applied to the surface of the flow-through component, it becomes smoother with each pass-through, and also has excellent wear resistance and toughness. A solid particle filler composed of cermet powder and sulfur-resistant toughening alloy powder is used in conjunction with the epoxy resin system. This solid filler has the toughness of metal and the high hardness of ceramic, and it does not damage the cutting tool during processing, while producing a smooth and delicate machined surface, exhibiting excellent processing performance. The addition of alloy powder with good sulfur corrosion resistance greatly improves the repair agent's resistance to sulfur corrosion in sulfur-containing slurry environments. The repair agent can be cured at room temperature or under heating conditions according to the temperature and humidity of the repair site, and the curing time can be controlled to 1–12 hours, facilitating construction.

[0024] In some embodiments, preferably, the cermet powder includes at least one of WC-Ni, WC-Co, Cr3C2-Ni, and Cr3C2-Co; the sulfur-resistant toughening alloy powder includes at least one of NiCr alloy, NiCrTi alloy, and Inconel 625 alloy; and the low-friction self-lubricating powder includes at least one of TiN, SiN, and BN.

[0025] In some embodiments, preferably, the curing agent comprises a polyamide curing agent.

[0026] In some embodiments, preferably, the repair agent further includes at least one of a diluent, a toughening agent, a defoamer, a pigment, and a leveling agent.

[0027] This invention also provides a method for preparing the repair agent, comprising the following steps:

[0028] (1) Component A: Prepare aliphatic epoxy resin, and then add metal ceramic powder, sulfur-resistant toughening alloy powder and low-friction self-lubricating powder;

[0029] (2) Component B: Prepare curing agent.

[0030] The preparation method of this invention, which separately configures components A and B, can avoid premature reaction between the curing agent and aliphatic epoxy resin, resulting in gel hardening of the repair agent and inability to perform construction operations; the process is simple and easy to operate, and is convenient for promotion and application in industrial production.

[0031] In some embodiments, preferably, the preparation of the aliphatic epoxy resin in step (1) includes:

[0032] a. Using hydrogen peroxide as an oxidant, propylene oxide is prepared by epoxidation of aliphatic compounds in an acidic environment.

[0033] b. Mix the propylene oxide obtained in step (a) with bisphenol A epoxy resin evenly and react to obtain an aliphatic epoxy resin.

[0034] More preferably, in step (b), the weight ratio of propylene oxide to bisphenol A epoxy resin is 8:2.

[0035] In some embodiments, preferably, step (1) further includes immersing the cermet powder, sulfur-resistant toughened alloy powder, and low-friction self-lubricating powder in an alkaline solution for etching treatment before adding them to an aliphatic epoxy resin. More preferably, the alkaline solution is NaOH with a mass fraction of 20-50%; the etching treatment temperature is 30-70°C, and the etching treatment time is 20-45 minutes. Even more preferably, after the etching treatment, solid-liquid separation is performed to filter out the powder, and the powder is rinsed with clean water until the pH value of the washing solution is 7-8, and the powder is then dried for later use.

[0036] In this embodiment of the invention, etching the powder particles can further increase the surface roughness of the powder particles, improve the adhesion of the resin to the powder particles, and enable the repair agent to have excellent bonding strength after curing. Even in a slurry environment at 70°C, the cured structure still has high bonding strength.

[0037] In some embodiments, preferably, step (1) further includes adding an auxiliary agent, which includes at least one of a diluent, toughening agent, defoamer, pigment, and leveling agent. More preferably, the amount of the diluent added is 3-10%, the amount of the toughening agent added is 1-3%, the amount of the defoamer added is 0.5-1.5%, and the amount of the leveling agent added is 1-1.5%; the amount of the auxiliary agent added is based on the mass of the mixture formed after mixing component A and component B. Even more preferably, the diluent is an active diluent, which includes at least one of propylene glycidyl ether, butyl glycidyl ether, and phenyl glycidyl ether; the toughening agent includes carboxyl-terminated modified nitrile rubber; the defoamer includes polydimethylsiloxane (PDMS); and the leveling agent includes polyacrylate.

[0038] In some embodiments, preferably, in step (2), the curing agent is a polyamide curing agent, and the preparation of the polyamide curing agent includes: reacting an amide and an anhydride at 100-120°C and 101.3-121.56 kPa for 4-6 hours. More preferably, the molar ratio of the amide to the anhydride is (1-1.5):1. Even more preferably, after the reaction is completed, the curing agent is subjected to dehydration, decolorization, and filtration treatment.

[0039] The application of the repair agent of the present invention or the repair agent prepared by the preparation method of the present invention in a sulfur-containing slurry environment.

[0040] The technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0041] Example 1

[0042] Component A

[0043] (1) Stir 100 parts by weight of aliphatic epoxy resin at a speed of 60 rpm on a disperser to avoid foaming.

[0044] (2) Add 100 parts by weight of cermet powder (60 parts of 300 mesh WC-Ni powder and 40 parts of 270 mesh Cr3C2-Ni powder), stir for 45 minutes, then add 60 parts by weight of sulfur-resistant toughening alloy powder (300 mesh NiCr alloy powder) and stir again for 30-60 minutes. After the slurry color is uniform, add 40 parts by weight of low friction self-lubricating powder (300 mesh TiN powder: SiN powder: BN powder weight ratio 1:1:1) and stir again for 30-60 minutes.

[0045] (3) Transfer the mud to a vacuum mixer, evacuate to a low pressure of 10Pa, and further stir and degas. After vacuum stirring for 30 minutes, restore to normal pressure, put the mud in the clay state into a plastic bag and tie it, then put it into a plastic bucket, seal it and store it away from light.

[0046] Component B: Prepare 40 parts by weight of polyamide curing agent: Mix amide and acid anhydride in a 1:1 molar ratio, react at 100℃ and 101.3KPa for 5h, and then dehydrate, decolorize, and filter to remove impurities. Store the synthesized polyamide curing agent in a cool, dry, and well-ventilated place.

[0047] When using the repair agent, mix component A and component B, then add 5 parts by weight of diluent and mix thoroughly.

[0048] Example 2

[0049] Component A

[0050] (1) Stir 120 parts by weight of aliphatic epoxy resin at a speed of 60 rpm on a disperser to avoid foaming;

[0051] (2) Add 120 parts by weight of metal ceramic powder (70 parts of 300 mesh WC-Ni powder and 30 parts of 270 mesh WC-Co powder), stir for 50 minutes, then add 80 parts by weight of sulfur-resistant toughening alloy powder (300 mesh NiCr alloy powder) and stir again for 45 minutes. After the slurry color is uniform, add 40 parts by weight of low friction self-lubricating powder (300 mesh TiN powder and 300 mesh BN powder, weight ratio 1:1) and stir again for 45 minutes.

[0052] (3) Transfer the mud to a vacuum mixer, evacuate to a low pressure of 10Pa, and further stir and degas. After vacuum stirring for 30 minutes, restore to normal pressure, put the mud in the clay state into a plastic bag and tie it, then put it into a plastic bucket, seal it and store it away from light.

[0053] Component B: Prepare 50 parts by weight of polyamide curing agent: Mix amide and acid anhydride at a molar ratio of 1:1.5, react at 110℃ and 110KPa for 6 hours, and then perform dehydration, decolorization, and filtration to remove impurities. Store the synthesized polyamide curing agent in a cool, dry, and well-ventilated place.

[0054] When using the repair agent, mix component A and component B, then add 10 parts by weight of diluent and mix thoroughly.

[0055] Example 3

[0056] Component A

[0057] (1) Stir 150 parts by weight of aliphatic epoxy resin at a speed of 50 rpm on a disperser to avoid foaming.

[0058] (2) Add 150 parts by weight of cermet powder (70 parts of 300 mesh WC-Ni powder and 30 parts of 270 mesh Cr3C2-Co powder), stir for 50 minutes, then add 100 parts by weight of sulfur-resistant toughening alloy powder (300 mesh NiCr alloy powder) and stir again for 50 minutes. After the slurry color is uniform, add 80 parts by weight of low friction self-lubricating powder (such as 300 mesh TiN powder and 300 mesh SiN powder, with a weight ratio of 1:1) and stir again for 60 minutes.

[0059] (3) Transfer the mud to a vacuum mixer, evacuate to a low pressure of 8Pa, and further stir and degas. After vacuum stirring for 45 minutes, restore to normal pressure, put the mud in the clay state into a plastic bag and tie it, then put it into a plastic bucket, seal it and store it away from light.

[0060] Component B: Prepare 60 parts by weight of polyamide curing agent: Mix amide and acid anhydride at a molar ratio of 1:1.2, react at 110℃ and 121.56KPa for 4h, and then dehydrate, decolorize, and filter to remove impurities. Store the synthesized polyamide curing agent in a cool, dry, and well-ventilated place.

[0061] When using the repair agent, mix component A and component B, then add 15 parts by weight of diluent and mix thoroughly.

[0062] Example 4

[0063] The preparation method of this embodiment is the same as that of Example 1, except that: before adding the metal-ceramic mixed powder, sulfur-resistant toughened alloy powder, and low-friction self-lubricating powder in step (2), the powder is first etched in a 30% NaOH solution at 50°C for 30 minutes, filtered, rinsed with water, and then dried.

[0064] Comparative Example 1

[0065] The preparation method of this comparative example is the same as that of Example 1, except that WC-Ni in step (2) is replaced with WC and Cr3C2-Ni is replaced with Cr3C2.

[0066] Comparative Example 2

[0067] The comparative example uses a commonly used diamond abrasive repair agent in the prior art, which consists of 20 parts bisphenol epoxy resin, 2 parts benzyl glycidyl ether, 75 parts silicon carbide powder, 22 parts polyetheramine curing agent, and 1.5 parts propyltriethoxysilane, by weight.

[0068] The repair agents prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to curing treatment. In Examples 1-4 and Comparative Example 1, components A and B were directly mixed and stirred evenly, cured at 50°C for 5 hours, and then cured at 80°C for 1 hour. Comparative Example 2 used the same curing conditions as Examples 1-4 and Comparative Example 1 (since bisphenol epoxy resin is a thermosetting resin, it can be cured by direct heat treatment). Repair agent samples were obtained, and the performance of the repair agent samples was tested. The results are shown in Table 1.

[0069] Table 1

[0070]

[0071] Note: Adhesion is evaluated by peel strength after the repair agent is uniformly applied to the substrate. The test method is to separate the repair agent coating from the substrate at a separation angle of 180 degrees and monitor the average load per unit width of the bonding line.

[0072] Test conditions for tensile strength: Refer to GB / T 6329-1996 "Determination of tensile strength of butt joints of adhesives".

[0073] Shear strength test conditions: Refer to GB / T 33334-2016 "Test method for tensile shear strength of single lap joint of adhesives (composite to composite)".

[0074] Test method for resistance to sulfur-containing slurry corrosion: The repair agent sample is immersed in sulfur-containing slurry, and the changes in properties such as weight change, volume expansion, or tensile strength of the repair agent sample relative to the initial sample after immersion are tested to evaluate the sample's resistance to sulfur-containing slurry corrosion. This invention evaluates the sample's resistance to sulfur-containing slurry corrosion based on the change in tensile strength of the sample relative to the initial sample after immersion. The corrosion slurry is a mixed solution of sodium sulfate and sodium chloride, with a total mass concentration of 5% (Na2SO4:NaCl = 4:1). The pH of the mixed solution is controlled to 6 by adding H2SO4, and the immersion corrosion time is 180 days. When the decrease in tensile strength of the sample relative to the initial sample after immersion does not exceed 3%, the sample is considered to have excellent resistance to sulfur-containing slurry corrosion.

[0075] Test method for high-temperature corrosion resistance: The workpiece coated with the repair agent and the repair agent sample were immersed in a 70°C corrosion slurry for 3 days, and the peel strength and tensile strength were tested. The corrosion slurry was a mixed solution of sodium sulfate and sodium chloride, with a total mass concentration of 5% (Na2SO4:NaCl = 4:1). The pH of the mixed solution was controlled to be 6 by adding H2SO4. The peel strength and tensile strength loss of the repair agents prepared in Examples 1-3 were within 10%, and the peel strength and tensile strength loss of the repair agent prepared in Example 4 were within 5%. However, the peel strength and tensile strength loss of the repair agents prepared in Comparative Examples 1 and 2 both exceeded 50%. This indicates that the repair agents prepared in the examples have good performance in a 70°C sulfur-containing slurry environment and have outstanding high-temperature corrosion resistance.

[0076] Self-lubricating property: The self-lubricating property of a sample is qualitatively evaluated by observing the surface condition of the sample after wear using a wear testing machine. When the sample has excellent self-lubricating property, the surface of the sample is smooth and has low roughness during the wear process; when the sample has poor self-lubricating property, the surface of the sample becomes increasingly rough and sticky as it is worn.

[0077] Machinability: Qualitative evaluation is conducted by performing machining tests such as turning and grinding on the samples. When the machinability of the repair agent sample is excellent, the processing difficulty is small, the processing efficiency is high, and the tool wear is small. Conversely, when the machinability of the sample is poor, the sample is difficult to process, the processing efficiency is low, and the tool wear is large.

[0078] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0079] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A patching agent, characterized by, The repair agent comprises component A and component B, the component A comprises 100-150 parts by weight of aliphatic epoxy resin, 100-150 parts by weight of cermet powder, 50-100 parts by weight of anti-sulfur toughening alloy powder and 30-80 parts by weight of low-friction self-lubricating powder, the component B comprises 40-60 parts by weight of curing agent; The cermet powder comprises at least one of WC-Ni, WC-Co, Cr3C2-Ni and Cr3C2-Co; the anti-sulfur toughening alloy powder comprises at least one of NiCr alloy, NiCrTi alloy and Inconel 625 alloy; the low-friction self-lubricating powder comprises at least one of TiN, SiN and BN.

2. The patch of claim 1 wherein, The curing agent comprises polyamide curing agent.

3. The patch of claim 1 or 2, wherein The repair agent further comprises at least one of diluent, toughening agent, defoaming agent, pigment and leveling agent.

4. A method of preparing the patch of any one of claims 1 to 3, characterized in that, The method comprises the following steps: (1) configuring component A: preparing aliphatic epoxy resin, and then adding cermet powder, anti-sulfur toughening alloy powder and low-friction self-lubricating powder; (2) configuring component B: preparing curing agent.

5. The method of claim 4, wherein the patch is prepared by the steps of: In the step (1), the cermet powder, anti-sulfur toughening alloy powder and low-friction self-lubricating powder are respectively soaked in alkaline solution for etching treatment before being added into the aliphatic epoxy resin.

6. The method of claim 5, wherein the patch is prepared by the steps of: The alkaline solution is NaOH with mass fraction of 20-50%; the etching treatment is carried out at temperature of 30-70 ℃ for 20-45 min.

7. The method of claim 4, wherein the patch is prepared by the steps of: In the step (1), an auxiliary agent is further added, the auxiliary agent comprises at least one of diluent, toughening agent, defoaming agent, pigment and leveling agent.

8. The method of claim 4, wherein the patch is prepared by the steps of: In the step (2), the curing agent is polyamide curing agent, and the preparation of the polyamide curing agent comprises: reacting amide and acid anhydride at 100-120 ℃ and 101.3-121.56 kPa for 4-6 h.

9. Application of the repair agent according to any one of claims 1-3 or prepared by the preparation method according to any one of claims 4-8 in sulfur-containing slurry environment.

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