High-strength heat-resistant thixotropic metal repairing agent as well as preparation method and application thereof

Abstract

The invention belongs to the field of polymer composite materials, and discloses a high-strength heat-resistant thixotropic metal repairing agent and a preparation method and application thereof.The repairing agent is prepared from a component A and a component B according to the mass ratio of 100: (1-5), the component A comprises the following components in parts by weight: 100 parts of high-strength heat-resistant vinyl ester resin, 15-25 parts of modified alumina powder, 20-30 parts of chopped glass fiber powder, 10-15 parts of iron oxide black, 1-2 parts of a dispersing agent BYK-W908, 1-2 parts of a coupling agent KH570, 0.5-1 part of an accelerant N, N-dimethyl benzylamine and 10-15 parts of fumed silica; and the component B comprises the following components in parts by weight: 8-12 parts of a carrier solvent, 5-10 parts of an initiator and 3-8 parts of a thixotropic agent. According to the metal repairing agent disclosed by the invention, the comprehensive performance balance of rapid curing, high strength, high temperature resistance and high thixotropy is realized through the collaborative design of two components and optimization of a gradient filler reinforcing system, a double-thixotropic agent regulation mechanism and a rapid curing system, and the technical limitations of low curing rate, low temperature resistance grade and easiness in sagging of a traditional repairing agent are effectively overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer composite materials, in particular to a high-strength heat-resistant thixotropic metal repair agent and a preparation method and application thereof. BACKGROUND

[0002] In the industrial field, core components such as turbine blades of aircraft engines, high-temperature pipelines of petrochemicals, cylinder blocks of automobile engines, and metal components of nuclear power equipment are long-term exposed to harsh service environments such as high temperature (200-300℃), vibration, and corrosion, and are prone to surface pit, crack, and local defect damage due to wear, stress fatigue, and medium corrosion. If such damage is not repaired in time, it will cause equipment sealing failure, structural strength attenuation, and even unplanned shutdown or safety accidents, so it is urgent to develop a rapid and reliable metal component repair technology.

[0003] The existing metal repair agent has significant technical limitations in actual application and cannot meet the needs of industrial harsh working conditions. The main technical defects are as follows: 1) low curing efficiency: the gel time of conventional repair agents is generally more than 2 hours, and complete curing requires more than 24 hours, which prolongs the equipment downtime period and significantly increases the production loss of enterprises; 2) insufficient temperature resistance: the long-term use temperature of most products is lower than 150℃, and the glass transition temperature (Tg) is <200℃, which easily causes softening deformation and a sharp decrease in mechanical strength under high-temperature working conditions of 200-300℃, and cannot guarantee long-term stable service; 3) lack of thixotropy: flow hanging phenomenon is easy to occur when repairing vertical surfaces, inclined surfaces, or complex surfaces (such as component corners and grooves), which makes it difficult to accurately control the thickness and geometric shape of the repair layer, resulting in poor uniformity and insufficient dimensional accuracy of the repaired part; 4) slow development of strength: the strength grows slowly in the initial curing stage, and the 2-hour strength is usually less than 50%, so the repaired component needs to be left for a long time before it can be put into use, further aggravating the equipment downtime loss. SUMMARY

[0004] In view of the above technical bottlenecks, the present application optimizes the dual-component synergistic design, gradient filler reinforcement system, dual-thixotropic agent regulation mechanism, and rapid curing system to develop a high-strength heat-resistant thixotropic metal repair agent and a preparation method and application thereof, so as to achieve a balance of comprehensive performance such as "rapid curing-high strength-resistance to high temperature-high thixotropy".

[0005] To achieve the above purpose, the following technical solutions are adopted in the present application:

[0006] The first aspect of the present application is to provide a high-strength heat-resistant thixotropic metal repair agent, which is prepared from A component and B component with a mass ratio of 100: (1-5). The formulations of the components are as follows in terms of mass fraction:

[0007] A component: high-strength heat-resistant vinyl ester resin 100 parts, modified alumina powder 15-25 parts, chopped glass fiber powder 20-30 parts, iron oxide black 10-15 parts, dispersant BYK-W908 1-2 parts, coupling agent KH570 1-2 parts, promoter N,N-dimethyl benzylamine 0.5-1 part, fumed white carbon black 10-15 parts;

[0008] B component: carrier solvent 8-12 parts, initiator 5-10 parts, thixotropic agent 3-8 parts; the initiator is one or two of t-butyl peroxypivalate, t-butyl peroxynonoate, t-butyl peroxynonanoate.

[0009] Preferably, the high-strength heat-resistant vinyl ester resin is derived from patent CN202410697443.4, and the molecular structure contains a theoretical 4 functional group, and the cast body glass transition temperature is ≥220℃.

[0010] Preferably, the modified alumina powder has a mesh size of 1200-3000 mesh, a purity of ≥99%, and a Mohs hardness of 9.

[0011] Preferably, the chopped glass fiber powder has a mesh size of 200-500 mesh, and a fiber length of 0.1-0.3 mm.

[0012] Preferably, the iron oxide black has a mesh size of 700-900 mesh.

[0013] Preferably, the specific surface area of the fumed white carbon black is ≥200 m² / g.

[0014] Preferably, the particle size of the precipitated white carbon black is 10-20 nm.

[0015] Preferably, the carrier solvent is one or two of dibutyl phthalate, dioctyl phthalate, and dimethyl silicone oil; the thixotropic agent is one or two of precipitated white carbon black and fumed white carbon black.

[0016] Preferably, the A component formula is as follows in terms of mass parts: high-strength heat-resistant vinyl ester resin 100 parts, modified alumina powder 20 parts, chopped glass fiber powder 25 parts, iron oxide black 12 parts, dispersant BYK-W908 1.5 parts, coupling agent KH570 1.5 parts, promoter N,N-dimethyl benzylamine 0.8 parts, fumed white carbon black 12 parts.

[0017] Preferably, the initiator is tert-butyl peroxy isononanoate, the gel speed of which is between that of tert-butyl peroxy pivalate (too fast) and tert-butyl peroxy neodecanoate (too slow), meeting the timeliness requirement of "fast curing"; meanwhile, its decomposition rate is moderate, and it can continuously release free radicals in the later stage, promoting deepening of crosslinking and improving the speed of post-curing strength, which is superior to tert-butyl peroxy pivalate (insufficient free radicals in the later stage) and close to the strength development trend of tert-butyl peroxy neodecanoate.

[0018] Preferably, the B component is formulated as follows in terms of mass fraction: dimethyl silicone oil 10 parts, tert-butyl peroxy isononanoate 5 parts, and precipitated white carbon black 8 parts.

[0019] Preferably, the B component is formulated as follows in terms of mass fraction: dimethyl silicone oil 10 parts, tert-butyl peroxy isononanoate 5 parts, and fumed white carbon black 3 parts.

[0020] The second aspect of the present application is to provide a preparation method of the high-strength heat-resistant thixotropic metal repair agent as described in any one of the above aspects, comprising the following steps:

[0021] (1) Preparation of the A component

[0022] ① Pretreatment of the matrix: add the high-strength heat-resistant vinyl ester resin in the formula ratio into a planetary disperser with temperature control and stirring function, and stir at a low speed of 300 rpm, then add the dispersant BYK-W908 and the coupling agent KH570, and stir for 5 min until they are uniformly mixed;

[0023] ② Dispersion of the gradient filler: keep stirring, and then add the modified alumina powder, the chopped glass fiber powder and the iron oxide black in the formula ratio one by one, stir for 2 min after each addition, and then increase the speed to 1500 rpm after all the raw materials are added, and disperse at a high speed for 10 min under the condition of 25-30℃;

[0024] ③ Thixotropy adjustment and storage: reduce the speed to 500 rpm, add the accelerator N,N-dimethylbenzylamine and the fumed white carbon black in the formula ratio, stir for 8 min until a uniform thixotropic paste is formed, then detect the thixotropic index, which is 4.2-4.8, and then store the A component in a sealed container at 5-30℃ in the dark;

[0025] (2) Preparation of the B component

[0026] ① Mixing of raw materials: add the carrier solvent, the initiator and the thixotropic agent in the formula ratio into a kneader one by one, and preliminarily knead for 10 min to form a coarse paste;

[0027] ② Fine grinding: transfer the coarse paste into a three-roll grinder, control the roll gap to be 5-10 μm and the roll temperature to be below 30℃, and grind for 3 times to ensure no particles and uniform dispersion;

[0028] ③Storage: B group components are loaded into brown light-sealed containers, stored at 5~20℃, to prevent the initiator from decomposing under light, with a shelf life of 6 months.

[0029] Preferably, in step (1) ②, the temperature is controlled by the planetary dispersion machine jacket to avoid the heat generated by high-speed stirring from causing the resin to prematurely crosslink.

[0030] The third aspect of the present application is to provide a high-strength heat-resistant thixotropic metal repair agent as described in any one of the above for use in and application in the repair of petroleum chemical (high-temperature pipeline), metallurgy (steel roller), aerospace ground equipment, automobile engineering machinery (exhaust manifold), kiln (furnace door), and general industry (high-temperature fan), carbon fiber (glass fiber) composite material products, etc.

[0031] Preferably, the high-strength heat-resistant thixotropic metal repair agent can achieve about 30 min gel, 2 h strength reaching more than 80% of the full curing strength, and 12 h reaching more than 90% at room temperature.

[0032] Preferably, the high-strength heat-resistant thixotropic metal repair agent has a long-term use temperature of not less than 250℃, a glass transition temperature of not less than 300℃, a steel-steel shear strength of not less than 15 MPa, and a thixotropic index of 4.2~4.8.

[0033] The technical scheme adopted by the present application has the following technical effects compared with the prior art:

[0034] The high-strength heat-resistant thixotropic metal repair agent provided by the present application can achieve about 30 min gel, 2 h strength reaching more than 80% of the full curing strength, and 12 h reaching more than 90% at room temperature, has a long-term use temperature of not less than 250℃, a glass transition temperature of not less than 300℃, a steel-steel shear strength of not less than 15 MPa, and a thixotropic index of 4.2~4.8; the repair agent can be used for repairing high-temperature and complex profile metal parts in the fields of aerospace, petrochemical, etc., effectively overcoming the technical limitations of slow curing rate, low temperature resistance level, and easy sagging of traditional repair agents. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is the differential scanning calorimetry curve (DSC) of the high-strength heat-resistant thixotropic metal repair agent of the present application;

[0036] Figure 2 is the thermogravimetric curve (TG) / differential scanning calorimetry curve (DSC) of the high-strength heat-resistant thixotropic metal repair agent of the present application. DETAILED DESCRIPTION

[0037] The present application aims to provide a high-strength heat-resistant thixotropic metal repair agent with excellent comprehensive performance to achieve the following key objectives:

[0038] Fast curing performance: gelation is completed in about 30 minutes at room temperature, the strength can reach more than 80% of the full curing strength within 2 hours, and more than 90% within 12 hours, meeting the timeliness requirements of equipment rapid repair.

[0039] Excellent high-temperature resistance: long-term use temperature is not less than 250℃, and glass transition temperature is not less than 300℃, ensuring the structural stability and mechanical properties under high-temperature working conditions.

[0040] Significant thixotropy: no sagging phenomenon during construction on vertical surfaces and complex surfaces, excellent plasticizing ability, ensuring the dimensional accuracy of the repaired part.

[0041] High bonding strength: steel-steel shear strength is not less than 15 MPa, combined with metal substrate to ensure compactness, and the performance after repair is close to the original component.

[0042] Adjustable operation time: by adjusting the ratio of two components, the gel time can be accurately controlled in the range of 15-45 min to adapt to different construction conditions.

[0043] The present application adopts a two-component collaborative design, through precise selection of raw materials, optimization of ratio and process, realizes the performance balance of fast curing, high temperature resistance, excellent thixotropy and high bonding strength, and the specific technical scheme is as follows:

[0044] 1, Component composition (by mass fraction), as shown in Table 1:

[0045]

[0046] 2, Ratio relationship

[0047] The mass ratio of A component to B component is 100: (1-5), and the gel time is accurately controlled by adjusting the amount of B component to adapt to different scenes (at 23℃ environment):

[0048] 100:1: gel time is about 45 min, suitable for large area, complex shape repair, with sufficient operation time;

[0049] 100:3: gel time is 25-35 min, which is the optimal ratio, considering operation and curing efficiency, suitable for conventional repair;

[0050] 100:5: gel time is about 15 min, suitable for small area, emergency plugging, and fast curing.

[0051] 3, Preparation process

[0052] (1) Preparation of A component:

[0053] ① Base pretreatment: 100 parts of high-strength heat-resistant vinyl ester resin are added to a planetary disperser with temperature control and stirring function, and stirred at a low speed of 300 rpm, 1-2 parts of dispersing agent BYK-W908 and 1-2 parts of coupling agent KH570 are added, and stirred for 5 min until mixed uniformly, to lay a foundation for filler dispersion;

[0054] ② Gradient filler dispersion: keep stirring, add 15-25 parts of modified alumina powder, 20-30 parts of chopped glass fiber powder, and 10-15 parts of 800 mesh iron oxide black in turn, and stir for 2 min after each addition to avoid agglomeration; after all the raw materials are added, the speed is increased to 1500 rpm, and the temperature is controlled at 25-30℃ by the planetary disperser jacket to disperse at a high speed for 10 min to prevent premature crosslinking of the resin;

[0055] ③ Thixotropy adjustment and storage: reduce the speed to 500 rpm, add 0.5-1 parts of accelerator N,N-dimethylbenzylamine and 10-15 parts of fumed white carbon black, and stir for 8 min to form a uniform thixotropic paste; after detecting the thixotropic index of 4.2-4.8, the A component is loaded into a sealed container and stored at 5-30℃ in the dark, with a shelf life of 6 months.

[0056] (2) Preparation of B component:

[0057] ① Raw material mixing: 8-12 parts of carrier solvent, 5-10 parts of initiator and 3-8 parts of thixotropic agent are added to a kneader in turn, and preliminary kneading is carried out for 10 min to form a coarse paste;

[0058] ② Fine grinding: the coarse paste is transferred to a three-roll grinding machine, the roll distance is controlled at 5-10 μm, and the roll temperature is below 30℃, and grinding is carried out for 3 times to ensure no particles and uniform dispersion;

[0059] ③ Storage: the B component is loaded into a brown light-proof sealed container and stored at 5-20℃ to prevent the initiator from decomposing under light, with a shelf life of 6 months.

[0060] The high-strength heat-resistant thixotropic metal repair agent provided by the application can gel in about 30 min at room temperature, the bonding strength can reach more than 80% of the full curing strength after 2 hours, more than 90% after 12 hours, the long-term temperature resistance is not less than 250℃, the glass transition temperature (Tg) is ≥300℃, the steel-steel shear strength is ≥15 MPa, the thixotropic index is 4.2-4.8, and there is no sagging phenomenon during construction; the product effectively overcomes the technical limitations of traditional repair agents such as slow curing speed and poor temperature resistance, and is suitable for repairing high-temperature metal parts in the fields of aerospace, petrochemical industry, etc.

[0061] The measured performance of the repair agent of the present application has the following advantages compared with the existing conventional repair agent (using commercially available Loctite 44143 metal repair agent) under the condition of room temperature, A:B = 100:3 (preferably the ratio) as shown in Table 2:

[0062]

[0063] The high-strength heat-resistant thixotropic metal repair agent provided by the present application has the following core innovations:

[0064] Resin-filler synergistic reinforcement system: based on the gradient filling strategy of modified alumina powder (microscopic filling, improving material hardness and high temperature stability) and short glass fiber powder (macroscopic reinforcement, improving toughness and crack resistance), combined with high-strength heat-resistant vinyl ester resin matrix, the chemical bonding of resin-filler-substrate interface is realized through coupling agent KH570. The strength retention rate of the system is ≥85% after aging at 250℃ / 1000h, which solves the industry technical bottleneck of high strength retention under high temperature working conditions.

[0065] Dual thixotropic agent synergistic regulation mechanism: the synergistic effect of A component fumed silica (main thixotropic agent, constructing three-dimensional network structure) and B component precipitated silica (auxiliary thixotropic agent, inhibiting delamination and strengthening thixotropy) makes the thixotropic index stable and maintained at 4.2~4.8. This design achieves the dual characteristics of "fluidity during construction (convenient for shaping) and no sagging after solidification (ensuring dimensional accuracy)", which meets the repair needs of various curved configurations.

[0066] Fast curing-high strength balance technology: through the precise molar ratio of tert-butyl peroxyisopropylate (initiator) and N,N-dimethylbenzylamine (accelerator), controllable gelation within 30 min is realized; combined with the reinforcing effect of gradient filler, the material has a strength of more than 80% of the initial strength after 2h of curing, more than 90% after 12h, and the steel-steel shear strength is ≥15 MPa, which solves the technical paradox between fast curing system and high strength demand.

[0067] Adjustable performance and long-term storage compatibility: through the ratio design of A:B = 100:(1~5), the gel time can be precisely controlled in the range of 15~45 min, which is suitable for different construction scenes. The B component uses dimethyl silicone oil as a separation medium, effectively isolating oxygen and ultraviolet light, inhibiting the pre-decomposition of the initiator, so that the storage stability of A and B components is 6 months, thereby solving the technical contradiction of long-term storage of fast curing materials.

[0068] The performance of the high-strength heat-resistant thixotropic metal repair agent of the present application is tested by the following performance test method:

[0069] Steel-steel shear strength: tested according to GB / T7124-2008 standard, sample is steel-steel bonding piece, tensile speed 2 mm / min;

[0070] Gel time: tested according to GB / T13477.5-2002 standard, record the time from mixing completion to non-sticky hand at room temperature (23℃±2℃);

[0071] Glass transition temperature (Tg): tested by differential scanning calorimetry (DSC), heating rate 5℃ / min, N2 atmosphere;

[0072] Long-term use temperature: tested by 250℃ / 1000h heat aging test, shear strength retention rate after aging, retention rate≥85% is judged as long-term use temperature≥250℃;

[0073] Thixotropy index: tested by rotary viscometer, viscosity at static state (1 rpm) and shear state (100 rpm) are tested respectively, thixotropy index = static viscosity / shear viscosity;

[0074] 2h / 12h strength ratio: tested according to GB / T2567-2021, tensile strength after curing for 2h and 12h, and the ratio to the completely cured (24h) strength;

[0075] Sagging resistance: apply 10mm thick repair agent on vertical steel sheet, stand for 30min at room temperature, observe whether sagging or deformation occurs.

[0076] The application will be described in detail and specifically through specific examples, so that the application can be better understood, but the following examples do not limit the scope of the application. The raw materials used in the examples are all commercially available conventional products, among which the high-strength heat-resistant vinyl ester resin is the 4-functional high-strength heat-resistant vinyl ester resin prepared in Example 4 of patent CN202410697443.4, and other raw materials such as modified alumina powder, chopped glass fiber powder, fumed white carbon black, etc. are all industrial-grade pure.

[0077] Example 1 (preferred ratio, A:B=100:3)

[0078] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0079] A component: high-strength heat-resistant vinyl ester resin 100 parts, 2000 mesh modified alumina powder 20 parts (purity 99%), 300 mesh chopped glass fiber powder 25 parts (length 0.2 mm), 800 mesh iron oxide black 12 parts, dispersant BYK-W908 1.5 parts, coupling agent KH570 1.5 parts, accelerator N,N-dimethylbenzylamine 0.8 parts, fumed white carbon black 12 parts (specific surface area 200 m² / g).

[0080] B component: dimethyl silicone oil 10 parts, tert-butyl peroxy isononanoate 5 parts, precipitated white carbon black 8 parts.

[0081] A:B mass ratio = 100:3 (A component 100 parts, B component 3 parts).

[0082] Based on the above formula, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0083] A component preparation: 100 parts of high-strength heat-resistant vinyl ester resin are added to a jacketed temperature-controlled planetary disperser, stirred at a low speed of 300 rpm, 1.5 parts of BYK-W908 and 1.5 parts of KH570 are added, and stirred for 5 min until dissolved; 20 parts of modified alumina powder, 25 parts of chopped glass fiber powder, and 12 parts of 800 mesh iron oxide black are added in turn, each time stirring for 2 min; the speed is increased to 1500 rpm, and high-speed dispersion is carried out for 10 min at 28°C; reduce to 500 rpm, add 0.8 parts of accelerator and 12 parts of fumed white carbon black, stir for 8 min, detect thixotropic index 4.5, and seal for storage.

[0084] B component preparation: 10 parts of dimethyl silicone oil, 5 parts of tert-butyl peroxy isononanoate and 8 parts of precipitated white carbon black are added to a kneader in turn, and a rough paste is formed by preliminary kneading for 10 min; the rough paste is transferred to a three-roll mill, the roll gap is controlled to be 5-10 μm, the roll temperature is below 30°C, and the grinding is carried out for 3 times to ensure no particles and uniform dispersion; seal and store in a brown bottle.

[0085] Mixed use: weigh A and B components in proportion, mass ratio A:B = 100:3, stir for 2.5 min until the color is consistent, and complete the coating within 15 min.

[0086] Example 2 (A:B = 100:1, large area repair adaptation)

[0087] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0088] A component: high-strength heat-resistant vinyl ester resin 100 parts, modified alumina powder 20 parts (purity 99%), 300 mesh chopped glass fiber powder 25 parts (length 0.2 mm), 800 mesh iron oxide black 12 parts, dispersant BYK-W908 1.5 parts, coupling agent KH570 1.5 parts, accelerator N,N-dimethyl benzylamine 0.8 parts, fumed white carbon black 12 parts (specific surface area 200 m² / g).

[0089] B component: dimethyl silicone oil 10 parts, tert-butyl peroxy isononanoate 5 parts, precipitated white carbon black 8 parts.

[0090] A:B mass ratio = 100:1 (A component 100 parts, B component 1 part).

[0091] Based on the above formula, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0092] The preparation process is the same as that of Example 1. When mixing, 100 parts of A component and 1 part of B component are stirred uniformly, and the operation time is reserved for 30 min (adapted to large area repair).

[0093] Example 3 (A:B=100:5, emergency plugging adaptation)

[0094] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0095] A component: 100 parts of high-strength heat-resistant vinyl ester resin, 20 parts of 2000 mesh modified alumina powder (purity 99%), 25 parts of 300 mesh chopped glass fiber powder (length 0.2 mm), 12 parts of 800 mesh black iron oxide, 1.5 parts of dispersant BYK-W908, 1.5 parts of coupling agent KH570, 0.8 parts of accelerator N,N-dimethylbenzylamine, and 12 parts of fumed white carbon black (specific surface area 200 m² / g).

[0096] B component: 10 parts of dimethyl silicone oil, 5 parts of tert-butyl peroxy isononanoate, and 8 parts of precipitated white carbon black.

[0097] A:B mass ratio=100:5 (100 parts of A component and 5 parts of B component).

[0098] Based on the above formula, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0099] The preparation process is the same as that of Example 1. When mixing, 100 parts of A component and 5 parts of B component are stirred uniformly, and the coating is completed within 10 min (adapted to emergency plugging).

[0100] Example 4 (modified alumina powder 3000 mesh, high density repair)

[0101] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0102] A component: 100 parts of high-strength heat-resistant vinyl ester resin, 22 parts of 3000 mesh modified alumina powder (purity 99%), 25 parts of 300 mesh chopped glass fiber powder, 12 parts of 800 mesh black iron oxide, 1.5 parts of BYK-W908, 1.5 parts of KH570, 0.8 parts of accelerator, and 12 parts of fumed white carbon black.

[0103] B component: 10 parts of dimethyl silicone oil, 5 parts of tert-butyl peroxy isononanoate, and 8 parts of precipitated white carbon black.

[0104] A:B mass ratio=100:3 (100 parts of A component and 3 parts of B component).

[0105] Based on the above formula, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0106] The same as Example 1, only the mesh number of the modified alumina powder is adjusted to 3000 mesh (to improve the filling density).

[0107] Example 5 (short glass fiber powder 500 mesh, high toughness repair)

[0108] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0109] A component: high-strength heat-resistant vinyl ester resin 100 parts, 2000 mesh modified alumina powder 20 parts, 500 mesh short glass fiber powder 28 parts (length 0.1 mm), 800 mesh iron oxide black 12 parts, BYK-W908 1.5 parts, KH570 1.5 parts, accelerator 0.8 parts, fumed white carbon black 12 parts.

[0110] B component: dimethyl silicone oil 10 parts, tert-butyl peroxy isononanoate 5 parts, precipitated white carbon black 8 parts.

[0111] A:B mass ratio = 100:3 (A component 100 parts, B component 3 parts).

[0112] Based on the above formula, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0113] The same as Example 1, only the mesh number of the short glass fiber powder is adjusted to 500 mesh (to improve toughness).

[0114] Comparative Example 1 (A component without fumed white carbon black, thixotropy is missing)

[0115] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0116] A component: high-strength heat-resistant vinyl ester resin 100 parts, 2000 mesh modified alumina powder 20 parts (purity 99%), 300 mesh short glass fiber powder 25 parts (length 0.2 mm), 800 mesh iron oxide black 12 parts, dispersant BYK-W908 1.5 parts, coupling agent KH570 1.5 parts, accelerator N,N-dimethylbenzylamine 0.8 parts.

[0117] B component: dimethyl silicone oil 10 parts, tert-butyl peroxy isononanoate 5 parts, precipitated white carbon black 8 parts.

[0118] A:B mass ratio = 100:3 (A component 100 parts, B component 3 parts).

[0119] Based on the above formula, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0120] The same as Example 1, only omit the addition of the A component fumed white carbon black.

[0121] Comparative Example 2 (without short-cut glass fiber powder, insufficient toughness and high-temperature stability)

[0122] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0123] A component: 100 parts of high-strength heat-resistant vinyl ester resin, 20 parts of 2000-mesh modified alumina powder (purity 99%), 12 parts of 800-mesh black iron oxide, 1.5 parts of dispersant BYK-W908, 1.5 parts of coupling agent KH570, 0.8 parts of accelerator N,N-dimethylbenzylamine, and 12 parts of fumed white carbon black (specific surface area 200 m² / g).

[0124] B component: 10 parts of dimethyl silicone oil, 5 parts of tert-butyl peroxy isononanoate, and 8 parts of precipitated white carbon black.

[0125] A:B mass ratio = 100:3 (100 parts of A component and 3 parts of B component).

[0126] Based on the above formulation, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0127] The same as Example 1, only omit the addition of the A component short-cut glass fiber powder.

[0128] Comparative Example 3 (using ordinary vinyl ester resin, insufficient temperature resistance)

[0129] A high-strength heat-resistant thixotropic metal repair agent is prepared from the following components:

[0130] A component: 100 parts of ordinary vinyl ester resin (model number: 901), 20 parts of 2000-mesh modified alumina powder (purity 99%), 25 parts of 300-mesh short-cut glass fiber powder (length 0.2 mm), 12 parts of 800-mesh black iron oxide, 1.5 parts of dispersant BYK-W908, 1.5 parts of coupling agent KH570, 0.8 parts of accelerator N,N-dimethylbenzylamine, and 12 parts of fumed white carbon black (specific surface area 200 m² / g).

[0131] B component: 10 parts of dimethyl silicone oil, 5 parts of tert-butyl peroxy isononanoate, and 8 parts of precipitated white carbon black.

[0132] A:B mass ratio = 100:3 (100 parts of A component and 3 parts of B component).

[0133] Based on the above formulation, the specific preparation method of the high-strength heat-resistant thixotropic metal repair agent is as follows:

[0134] The same as Example 1, only replace the high-strength heat-resistant vinyl ester resin with a common vinyl ester resin (model: 901).

[0135] Performance test:

[0136] The high-strength heat-resistant thixotropic metal repair agent prepared in Examples 1 to 5 and Comparative Examples 1 to 3 above was subjected to performance testing and comparative analysis using the corresponding test methods, and the test data are shown in Table 3 below.

[0137]

[0138] From the analysis of the test data in Table 3, it can be seen that the metal repair agent prepared in Example 4 is the optimal example, with the best overall performance, a steel-steel shear strength of 17.5 MPa, a gel time of 29 min (taking into account operation and efficiency), a glass transition temperature (Tg) of 342℃, a long-term use temperature of 282℃, and a thixotropic index of 4.5, 2 h / 12 h strength ratio and high-temperature strength retention rate are all at a high level, no flow, fully meet the core needs of "fast curing-high strength heat-resistant-excellent thixotropy".

[0139] Two-component ratio influence: Comparative Examples 1~3, A:B=100:3 has the best overall performance, 100:1 has sufficient operation time but reduced curing efficiency, 100:5 has fast curing but narrow operation window, only suitable for emergency scenarios.

[0140] Key raw material role: fumed white carbon black is the core of thixotropic performance (comparative example 1 thixotropic index drops sharply, flow failure); chopped glass fiber powder is the key to improving toughness and high-temperature stability (comparative example 2 strength and high-temperature retention rate decrease significantly); high-strength heat-resistant vinyl ester resin is the basis of temperature resistance, comparative example 3 glass transition temperature (Tg) and long-term use temperature drop sharply, cannot meet the high-temperature demand.

[0141] Raw material parameter influence: Example 4 (3000 mesh modified alumina) has higher density than Example 1, and slightly better strength and temperature resistance; Example 5 (500 mesh chopped glass fiber) has better toughness than Example 1, and slightly better high-temperature retention rate, but the overall performance improvement is limited, indicating that the preferred parameters (3000 mesh modified alumina, 300 mesh chopped glass fiber) of the present application have achieved performance balance.

[0142] In addition, taking the high-strength heat-resistant thixotropic metal repair agent prepared in Example 4 as an example, the physical properties of the repair agent were measured by thermal analysis techniques as the temperature or time changed. For example, Figure 1The differential scanning calorimetry curve (DSC) shown, the glass transition is shown as a stepwise offset of the baseline on the DSC curve, and the glass transition temperature Tg of the metal repair agent is 361.1℃ from the DSC graph. It is shown that the metal repair agent can maintain a rigid structure at high temperature and is not prone to softening, deformation and other problems due to temperature rise, and has excellent thermal stability. The metal repair agent does not undergo glass transition until about 361.1℃, which shows that it can maintain performance in a temperature environment much higher than conventional polymers, and therefore has good temperature resistance.

[0143] and the thermogravimetric curve (TG curve, upper red curve) / differential scanning calorimetry curve (DSC, lower green curve) as shown in Figure 2 The low-temperature section (30℃~350℃ or so): the weight is maintained at more than 96%, almost no weight loss, which shows that the metal repair agent is stable in this temperature range, and there is no loss of volatile components (such as low molecular solvent, unreacted monomer, etc.), which preliminarily embodies the low-temperature thermal stability. The medium-temperature section (351.39℃~422.06℃ or so): from "start Y=96.613%, start X=351.39℃" to "start Y=70.583%, start X=422.06℃", the weight decreases from about 96.6% to about 70.6%, which is the main weight loss interval, corresponding to the thermal decomposition of the organic binder phase or part of the components in the sample (such as polymer chain rupture, functional group decomposition, etc.). The high-temperature section (422.06℃~504.2℃): the weight further slowly decreases from about 70.6%, but still has a certain residual mass (finally about 65% or so), which shows that even at about 500℃, the sample is not completely decomposed, and there is a high-temperature resistant residual phase (such as inorganic filler, thermally stable crosslinked structure, etc.).

[0144] From the above thermal analysis, it can be seen that the metal repair agent of the present application has almost no weight loss below 300℃, and has no obvious glass transition, which shows that it has good thermal stability at low and medium temperatures. The main weight loss occurs at 350℃~420℃, but there is a large amount of residue even at 500℃, which shows that there are high-temperature resistant components (such as inorganic reinforcing phase, stable chemical bonding structure) in the system, which can maintain a certain structural integrity at high temperature, and therefore has good temperature resistance.

[0145] The specific embodiments of the present application are described in detail above, but they are only examples, and the present application is not limited to the specific embodiments described above. Any equivalent modifications and alternatives to the present application made by those skilled in the art are also within the scope of the present application. Therefore, any equivalent transformation and modification made without departing from the spirit and scope of the present application should be covered within the scope of the present application.

Claims

1. A high-strength, heat-resistant, thixotropic metal repair agent, characterized in that, It is formulated from component A and component B in a mass ratio of 100:(1~5). The formula of each component by mass parts is as follows: Component A: 100 parts high-strength heat-resistant vinyl ester resin, 15-25 parts modified alumina powder, 20-30 parts chopped glass fiber powder, 10-15 parts iron oxide black, 1-2 parts dispersant BYK-W908, 1-2 parts coupling agent KH570, 0.5-1 part accelerator N,N-dimethylbenzylamine, and 10-15 parts fumed silica; Component B: 8-12 parts of carrier solvent, 5-10 parts of initiator, and 3-8 parts of thixotropic agent; the initiator is one or two of tert-butyl peroxypentanoate, tert-butyl peroxyisononanoate, and tert-butyl peroxypentanoate.

2. The high-strength, heat-resistant, thixotropic metal repair agent according to claim 1, characterized in that, The high-strength, heat-resistant vinyl ester resin is derived from patent CN202410697443.

4. Its molecular structure contains theoretically 4 functional groups, and its glass transition temperature is ≥220℃.

3. The high-strength, heat-resistant, thixotropic metal repair agent according to claim 1, characterized in that, The modified alumina powder has a mesh size of 1200~3000 mesh, a purity of ≥99%, and a Mohs hardness of 9.

4. The high-strength, heat-resistant, thixotropic metal repair agent according to claim 1, characterized in that, The chopped glass fiber powder has a mesh size of 200-500 and a fiber length of 0.1-0.3 mm.

5. The high-strength, heat-resistant, thixotropic metal repair agent according to claim 1, characterized in that, The specific surface area of ​​the fumed silica is ≥200 m² / g.

6. The high-strength, heat-resistant, thixotropic metal repair agent according to claim 1, characterized in that, The carrier solvent is one or two of dibutyl phthalate, dioctyl phthalate, and dimethyl silicone oil; the thixotropic agent is one or two of precipitated silica and fumed silica.

7. The high-strength, heat-resistant, thixotropic metal repair agent according to claim 1, characterized in that, The formulation of component A by weight is as follows: 100 parts high-strength heat-resistant vinyl ester resin, 20 parts modified alumina powder, 25 parts chopped glass fiber powder, 12 parts iron oxide black, 1.5 parts dispersant BYK-W908, 1.5 parts coupling agent KH570, 0.8 parts accelerator N,N-dimethylbenzylamine, and 12 parts fumed silica.

8. The high-strength, heat-resistant, thixotropic metal repair agent according to claim 1, characterized in that, The formula for component B, by weight, is as follows: 10 parts dimethyl silicone oil, 5 parts tert-butyl peroxide, and 8 parts precipitated silica.

9. A method for preparing a high-strength, heat-resistant, thixotropic metal repair agent as described in any one of claims 1 to 8, characterized in that, Includes the following steps: (1) Preparation of component A ① Matrix pretreatment: Add the high-strength heat-resistant vinyl ester resin in the formula ratio to a planetary disperser with temperature control and stirring function, stir at a low speed of 300 rpm, add dispersant BYK-W908 and coupling agent KH570, and stir for 5 min until the mixture is uniform. ② Gradient filler dispersion: While maintaining stirring, add modified alumina powder, chopped glass fiber powder and iron oxide black in sequence according to the formula ratio. Stir for 2 minutes after each addition. After all the raw materials are added, increase the speed to 1500 rpm and disperse at high speed for 10 minutes at 25~30℃. ③Thixotropic adjustment and storage: Reduce the rotation speed to 500 rpm, add the accelerator N,N-dimethylbenzylamine and fumed silica in the formula ratio, stir for 8 min until a uniform thixotropic paste is formed, and after the thixotropic index is measured to be 4.2~4.8, put component A into a sealed container and store it at 5~30℃ away from light. (2) Preparation of component B ① Raw material mixing: Add the carrier solvent, initiator and thixotropic agent in the formula ratio to the kneader in sequence, and knead for 10 minutes to form a coarse paste; ② Fine grinding: Transfer the coarse paste into a three-roll mill, control the roller gap to 5~10 μm, the roller temperature to below 30℃, and grind 3 times to ensure no particles and uniform dispersion; ③ Storage: Place component B in a brown, light-proof, airtight container and store at 5~20℃ away from light.

10. The application of a high-strength, heat-resistant, thixotropic metal repair agent as described in any one of claims 1 to 8 in the use and repair of petrochemical, metallurgical, aerospace equipment, automotive engineering machinery, kilns and general industrial products, and carbon fiber composite materials.

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